[PATCH 00/16] device thermal limits represented in device tree nodes (v3)

[PATCH 00/16] device thermal limits represented in device tree nodes (v3)

[Eduardo Valentin]

Hello all,

Here is the continuation of work of representing hardware thermal properties
in device tree infrastructure. The present patch series is the third version
of this work. Previous versions were sent as RFCs and can be found here:
RFCv2: http://lkml.org/lkml/2013/8/23/594
RFCv1: http://lkml.org/lkml/2013/7/22/319

The major change between RFCv2 and this version is the fact that I am now
designing the binding accordingly to the common practice of creating links
from consumers to producers, as seen in regulators for instance. The change
make a thermal zone node point to used cooling devices and used sensor devices.
As direct need, cooling devices then need to be properly represented.
I am proposing to have cooling properties inside existing nodes, e.g. fan nodes,
cpu nodes. The change also required me to modify the existing thermal core
code to allow decoupling thermal zones from sensor code. Currently, the
binding proposal covers for the situation in which one thermal zone has
several sensor devices. Although this situation is not covered by the
current thermal framework code, and thus not supported by this series.
I believe this is not a stopper for this series, it can be done
in later patch sets.

The second patch includes a detailed documentation with examples
and the proposed code. In this patch series, a part from the dt parser,
there are changes in the cpufreq code to load the cpu cooling device,
also changes in the following sensor drivers: tmp102, lm75 and ti-soc-thermal.
Several changes in TI's SoC DT bindings are also included, as source
of tested examples.

The present patch series was tested on OMAP4430, OMAP4460, OMAP5430 and DRA7,
although the DRA7 changes were not sent as the core device tree support is
currently in the process to find its way to upstream.

All best,

Eduardo Valentin (16):
  drivers: thermal: allow registering without .get_temp
  drivers: thermal: introduce device tree parser
  drivers: thermal: cpu_cooling: introduce of_cpufreq_cooling_register
  cpufreq: cpufreq-cpu0: add dt node parsing for cooling device
    properties
  hwmon: lm75: expose to thermal fw via DT nodes
  hwmon: tmp102: expose to thermal fw via DT nodes
  thermal: ti-soc-thermal: use thermal DT infrastructure
  arm: dts: add omap4 CPU thermal data
  arm: dts: add omap4430 thermal data
  arm: dts: add omap4460 thermal data
  arm: dts: add cooling properties on omap4430 cpu node
  arm: dts: add cooling properties on omap4460 cpu node
  arm: dts: add omap5 GPU thermal data
  arm: dts: add omap5 CORE thermal data
  arm: dts: add omap5 thermal data
  arm: dts: add cooling properties on omap5 cpu node

 .../devicetree/bindings/cpufreq/cpufreq-cpu0.txt   |   7 +
 .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
 arch/arm/boot/dts/omap4-cpu-thermal.dtsi           |  41 ++
 arch/arm/boot/dts/omap443x.dtsi                    |  15 +-
 arch/arm/boot/dts/omap4460.dtsi                    |  15 +-
 arch/arm/boot/dts/omap5-core-thermal.dtsi          |  28 +
 arch/arm/boot/dts/omap5-gpu-thermal.dtsi           |  28 +
 arch/arm/boot/dts/omap5.dtsi                       |  15 +-
 drivers/cpufreq/Kconfig                            |   2 +-
 drivers/cpufreq/cpufreq-cpu0.c                     |  16 +
 drivers/hwmon/lm75.c                               |  46 +-
 drivers/hwmon/tmp102.c                             |  28 +
 drivers/thermal/Kconfig                            |  14 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/cpu_cooling.c                      |  31 +
 drivers/thermal/of-thermal.c                       | 763 +++++++++++++++++++++
 drivers/thermal/thermal_core.c                     |  19 +-
 drivers/thermal/thermal_core.h                     |   9 +
 drivers/thermal/ti-soc-thermal/ti-thermal-common.c |  77 ++-
 include/dt-bindings/thermal/thermal.h              |  27 +
 include/linux/cpu_cooling.h                        |  25 +
 include/linux/thermal.h                            |  28 +-
 22 files changed, 1701 insertions(+), 32 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
 create mode 100644 arch/arm/boot/dts/omap4-cpu-thermal.dtsi
 create mode 100644 arch/arm/boot/dts/omap5-core-thermal.dtsi
 create mode 100644 arch/arm/boot/dts/omap5-gpu-thermal.dtsi
 create mode 100644 drivers/thermal/of-thermal.c
 create mode 100644 include/dt-bindings/thermal/thermal.h

-- 
1.8.2.1.342.gfa7285d

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[PATCH 01/16] drivers: thermal: allow registering without .get_temp

[Eduardo Valentin]

This patch changes the thermal core driver to allow
registration of thermal zones without the .get_temp callback.

The idea behind this change is to allow lazy registration
of sensor callbacks.

The thermal zone will be disabled whenever the ops
does not contain a .get_temp callback. The sysfs interface
will be returning -EINVAL on any temperature read operation.

Cc: Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
---
 drivers/thermal/thermal_core.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 4962a6a..8a94300 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -402,7 +402,7 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
 	enum thermal_trip_type type;
 #endif
 
-	if (!tz || IS_ERR(tz))
+	if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
 		goto exit;
 
 	mutex_lock(&tz->lock);
@@ -455,6 +455,9 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 {
 	int count;
 
+	if (!tz->ops->get_temp)
+		return;
+
 	update_temperature(tz);
 
 	for (count = 0; count < tz->trips; count++)
@@ -1384,7 +1387,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips)
 		return ERR_PTR(-EINVAL);
 
-	if (!ops || !ops->get_temp)
+	if (!ops)
 		return ERR_PTR(-EINVAL);
 
 	if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
@@ -1488,6 +1491,9 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 
 	INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);
 
+	if (!tz->ops->get_temp)
+		thermal_zone_device_set_polling(tz, 0);
+
 	thermal_zone_device_update(tz);
 
 	if (!result)
-- 
1.8.2.1.342.gfa7285d

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[PATCH 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

This patch introduces a device tree bindings for
describing the hardware thermal behavior and limits.
Also a parser to read and interpret the data and feed
it in the thermal framework is presented.

This patch introduces a thermal data parser for device
tree. The parsed data is used to build thermal zones
and thermal binding parameters. The output data
can then be used to deploy thermal policies.

This patch adds also documentation regarding this
API and how to define tree nodes to use
this infrastructure.

Note that, in order to be able to have control
on the sensor registration on the DT thermal zone,
it was required to allow changing the thermal zone
.get_temp callback. For this reason, this patch
also removes the 'const' modifier from the .ops
field of thermal zone devices.

Cc: Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
---
 .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
 drivers/thermal/Kconfig                            |  13 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/of-thermal.c                       | 763 +++++++++++++++++++++
 drivers/thermal/thermal_core.c                     |   9 +-
 drivers/thermal/thermal_core.h                     |   9 +
 include/dt-bindings/thermal/thermal.h              |  27 +
 include/linux/thermal.h                            |  28 +-
 8 files changed, 1345 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
 create mode 100644 drivers/thermal/of-thermal.c
 create mode 100644 include/dt-bindings/thermal/thermal.h

diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
new file mode 100644
index 0000000..6664533
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/thermal.txt
@@ -0,0 +1,498 @@
+* Thermal Framework Device Tree descriptor
+
+Generic binding to provide a way of defining hardware thermal
+structure using device tree. A thermal structure includes thermal
+zones and their components, such as trip points, polling intervals,
+sensors and cooling devices binding descriptors.
+
+The target of device tree thermal descriptors is to describe only
+the hardware thermal aspects, not how the system must control or which
+algorithm or policy must be taken in place.
+
+There are five types of nodes involved to describe thermal bindings:
+- sensors: used to describe the device source of temperature sensing;
+- cooling devices: used to describe devices source of power dissipation control;
+- trip points: used to describe points in temperature domain defined to
+make the system aware of hardware limits;
+- cooling attachments: used to describe links between trip points and
+cooling devices;
+- thermal zones: used to describe thermal data within the hardware;
+
+It follows a description of each type of these device tree nodes.
+
+* Sensor devices
+
+Sensor devices are nodes providing temperature sensing capabilities on thermal
+zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
+providing temperature data to thermal zones. Temperature sensor devices may
+control one or more internal sensors.
+
+Required property:
+- #sensor-cells:	Used to provide sensor device specific information
+			while referring to it. Must be at least 1, in order
+			to identify uniquely the sensor instances within
+			the IC. See thermal zone binding for more details
+			on how consumers refer to sensor devices.
+
+* Cooling device nodes
+
+Cooling devices are nodes providing control on power dissipation. There
+are essentially two ways to provide control on power dissipation. First
+is by means of regulating device performance, which is known as passive
+cooling. Second is by means of activating devices in order to remove
+the dissipated heat, which is known as active cooling, e.g. regulating
+fan speeds. In both cases, cooling devices shall have a way to determine
+the level of cooling.
+
+Required property:
+- cooling-min-level:	A unsigned integer indicating the smallest
+			cooling level accepted. Typically 0.
+- cooling-max-level:	An unsigned integer indicating the largest
+			cooling level accepted.
+- #cooling-cells:	Used to provide cooling device specific information
+			while referring to it. Must be at least 2, in order
+			to specify minimum and maximum cooling level used
+			in the reference. See Cooling device attachments section
+			below for more details on how consumers refer to
+			cooling devices.
+
+* Trip points
+
+The trip node is a node to describe a point in the temperature domain
+in which the system takes an action. This node describes just the point,
+not the action.
+
+Required properties:
+- temperature:		the trip temperature level, in milliCelsius.
+- hysteresis:		a (low) hysteresis value on 'temperature'. This is a
+			relative value, in milliCelsius.
+- type:			the trip type. Here is the type mapping:
+	THERMAL_TRIP_ACTIVE	0:	A trip point to enable active cooling
+	THERMAL_TRIP_PASSIVE	1:	A trip point to enable passive cooling
+	THERMAL_TRIP_HOT	2:	A trip point to notify emergency
+	THERMAL_TRIP_CRITICAL	3:	Hardware not reliable.
+
+Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
+
+* Cooling device attachments
+
+The cooling device attachments node is a node to describe how cooling devices
+get assigned to trip points of the zone. The cooling devices are expected
+to be loaded in the target system.
+
+Required properties:
+- cooling-device:	A phandle of a cooling device with its parameters,
+			referring to which cooling device is used in this
+			binding. The required parameters are: the minimum
+			cooling level and the maximum cooling level used
+			in this attach.
+- trip:			A phandle of a trip point node within the same thermal
+			zone.
+
+Optional property:
+- contribution:		The cooling contribution to the thermal zone of the
+			referred cooling device at the referred trip point.
+			The contribution is a value from 0 to 100. The sum
+			of all cooling contributions within a thermal zone
+			must never exceed 100.
+
+Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
+limit parameters means:
+(i)   - minimum level allowed for minimum cooling level used in the reference.
+(ii)  - maximum level allowed for maximum cooling level used in the reference.
+Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
+
+* Thermal zones
+
+The thermal-zone node is the node containing all the required info
+for describing a thermal zone, including its cdev bindings. The thermal_zone
+node must contain, apart from its own properties, one node containing
+trip nodes and one node containing all the zone cooling attachments.
+
+Required properties:
+- passive-delay:	The maximum number of milliseconds to wait between polls
+			when performing passive cooling.
+- polling-delay:	The maximum number of milliseconds to wait between polls
+			when checking this thermal zone.
+- sensors:		A list of sensor phandles and their parameters. The
+			required parameter is the sensor id, in order to
+			identify internal sensors when the sensor IC features
+			several sensing units.
+- trips:		A sub-node containing several trip point nodes required
+			to describe the thermal zone.
+- cooling-attachments	A sub-node containing several cooling device attaches
+			nodes, used to describe the relation between trips
+			and cooling devices.
+
+Optional property:
+- coefficients:		An array of integers (one signed cell) containing
+			coefficients to compose a linear relation between
+			the sensors described in the sensors property.
+			Coefficients defaults to 1, in case this property
+			is not specified. A simple linear polynomial is used:
+			Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
+
+			The coefficients are ordered and they match with sensors
+			by means of sensor ID. Additional coefficients are
+			interpreted as constant offsets.
+
+Note: The delay properties are bound to the maximum dT/dt (temperature
+derivative over time) in two situations for a thermal zone:
+(i)  - when active cooling is activated (passive-delay); and
+(ii) - when the zone just needs to be monitored (polling-delay).
+The maximum dT/dt is highly bound to hardware power consumption and dissipation
+capability.
+
+* Examples
+
+Below are several examples on how to use thermal data descriptors
+using device tree bindings:
+
+(a) - CPU thermal zone
+
+The CPU thermal zone example below describes how to setup one thermal zone
+using one single sensor as temperature source and many cooling devices and
+power dissipation control sources.
+
+#include <dt-bindings/thermal/thermal.h>
+
+cpus {
+	cpu0: cpu@0 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <3>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+	...
+};
+
+&i2c1 {
+	...
+	fan0: fan@0x48 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <9>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+                cpu-alert0: cpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_ACTIVE>;
+                };
+                cpu-alert1: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-alert0>;
+			cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
+		};
+		attach1 {
+			trip = <&cpu-alert1>;
+			cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
+		};
+		attach2 {
+			trip = <&cpu-alert1>;
+			cooling-device =
+				<&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
+		};
+	};
+};
+
+In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
+the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
+via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
+zone 'cpu-thermal' using its cooling levels from its minimum to 4, when it
+reaches trip point 'cpu-alert0' at 90C, as an example of active cooling. The
+same cooling device is used at 'cpu-alert1', but from 5 to its maximum level.
+The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
+passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
+which is a trip point at 100C.
+
+(b) - IC with several internal sensors
+
+The example below describes how to deploy several thermal zones based off a
+single sensor IC, assuming it has several internal sensors. This is a common
+case on SoC designs with several internal IPs that may need different thermal
+requirements, and thus may have their own sensor to monitor or detect internal
+hotspots in their silicon.
+
+#include <dt-bindings/thermal/thermal.h>
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                cpu-alert: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+gpu-thermal: gpu-thermal {
+	passive-delay = <120>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     1>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                gpu-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                gpu-crit: gpu-crit {
+                        temperature = <105000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+dsp-thermal: dsp-thermal {
+	passive-delay = <50>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     2>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                dsp-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                dsp-crit: gpu-crit {
+                        temperature = <135000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+In the example above there is one bandgap IC which has the capability to
+monitor three sensors. The hardware has been designed so that sensors are
+placed on different places in the DIE to monitor different temperature
+hotspots: one for CPU thermal zone, one for GPU thermal zone and the
+other to monitor a DSP thermal zone.
+
+Thus, there is a need to assign each sensor provided by the bandgap IC
+to different thermal zones. This is achieved by means of using the
+#sensor-cells property and using the first parameter as sensor ID.
+In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
+bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
+is used to monitor DSP thermal zone. Each zone may be uncorrelated,
+having its own dT/dt requirements, trips and cooling attachments.
+
+
+(c) - Several sensors within one single thermal zone
+
+The example below illustrates how to use more than one sensor within
+one thermal zone.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc: sensor@0x49 {
+		...
+		#sensor-cells = <1>;
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0	0>,
+		  <&adc		0>;
+
+		/* hotspot = 100 * bandgap - 120 * adc + 484 */
+	coefficients = 		<100	-120	484>;
+
+        trips {
+		...
+        };
+
+	cooling-attachments {
+		...
+	};
+};
+
+In some cases, there is a need to use more than one sensor to extrapolate
+a thermal hotspot in the silicon. The above example illustrate this situation.
+For instance, it may be the case that a sensor external to CPU IP may be place
+close to CPU hotspot and together with internal CPU sensor, it is used
+to determine the hotspot. The hyppotetical extrapolation rule would be:
+		hotspot = 100 * bandgap - 120 * adc + 484
+
+The same idea can be used to add fixed offset:
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+		hotspot = 1 * adc + 6000
+
+In the above equation, the hotspot is always 6C higher than what is read
+from the sensor ADC. The binding would be then:
+		/* sensor       ID */
+        sensors =  <&adc	0>;
+
+		/* hotspot = 1 * adc + 6000 */
+	coefficients = 		<1	6000>;
+
+(d) - Board thermal
+
+The board thermal example below illustrates how to setup one thermal zone
+with many sensors and many cooling devices.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc-dummy: sensor@0x50 {
+		...
+		#sensor-cells = <1>; /* sensor internal ID */
+	};
+};
+
+batt-thermal {
+	passive-delay = <500>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+	/* sensor       ID */
+	sensors = <&adc-dummy     4>;
+
+	trips {
+		...
+	};
+
+	cooling-attachments {
+		...
+	};
+};
+
+board-thermal: board-thermal {
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+		/* sensor       ID */
+	sensors = <&adc-dummy     0>,
+		  <&adc-dummy     1>,
+		  <&adc-dymmy     2>;
+			/*
+			 * An array of coefficients describing the sensor
+			 * linear relation. E.g.:
+			 * z = c1*x1 + c2*x2 + c3*x3
+			 */
+	coefficients =		<1200	-345	890>;
+
+	trips {
+		/* Trips are based on resulting linear equation */
+		cpu-trip: cpu-trip {
+			temperature = <60000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		gpu-trip: gpu-trip {
+			temperature = <55000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		}
+		lcd-trip: lcp-trip {
+			temperature = <53000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		crit-trip: crit-trip {
+			temperature = <68000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_CRITICAL>;
+		};
+	};
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-trip>;
+			cooling-device = <&cpu0 0 2>;
+			contribution = <55>;
+		};
+		attach1 {
+			trip = <&gpu-trip>;
+			cooling-device = <&gpu0 0 2>;
+			contribution = <20>;
+		};
+		attach2 {
+			trip = <&lcd-trip>;
+			cooling-device = <&lcd0 5 10>;
+			contribution = <15>;
+		};
+	};
+};
+
+The above example is a mix of previous examples, a sensor IP with several internal
+sensors used to monitor different zones, one of them is composed by several sensors and
+with different cooling devices.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index dbfc390..dd81eb8 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -29,6 +29,19 @@ config THERMAL_HWMON
 	  Say 'Y' here if you want all thermal sensors to
 	  have hwmon sysfs interface too.
 
+config THERMAL_OF
+	bool
+	prompt "APIs to parse thermal data out of device tree"
+	depends on OF
+	default y
+	help
+	  This options provides helpers to add the support to
+	  read and parse thermal data definitions out of the
+	  device tree blob.
+
+	  Say 'Y' here if you need to build thermal infrastructure
+	  based on device tree.
+
 choice
 	prompt "Default Thermal governor"
 	default THERMAL_DEFAULT_GOV_STEP_WISE
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 584b363..4b03956 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
 
 # interface to/from other layers providing sensors
 thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
+thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
 
 # governors
 thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
new file mode 100644
index 0000000..a6dde56
--- /dev/null
+++ b/drivers/thermal/of-thermal.c
@@ -0,0 +1,763 @@
+/*
+ *  of-thermal.c - Generic Thermal Management device tree support.
+ *
+ *  Copyright (C) 2013 Texas Instruments
+ *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
+ *
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/string.h>
+
+/***   Private data structures to represent thermal device tree data ***/
+
+/**
+ * struct __thermal_trip - representation of a point in temperature domain
+ * @np: pointer to struct device_node that this trip point was created from
+ * @temperature: temperature value in miliCelsius
+ * @hysteresis: relative hysteresis in miliCelsius
+ * @type: trip point type
+ */
+
+struct __thermal_trip {
+	struct device_node *np;
+	unsigned long int temperature;
+	unsigned long int hysteresis;
+	enum thermal_trip_type type;
+};
+
+/**
+ * struct __thermal_bind_param - a match between trip and cooling device
+ * @cooling_device: a pointer to identify the referred cooling device
+ * @trip_id: the trip point index
+ * @usage: the percentage (from 0 to 100) of cooling contribution
+ * @min: minimum cooling level used at this trip point
+ * @max: maximum cooling level used at this trip point
+ */
+
+struct __thermal_bind_params {
+	struct device_node *cooling_device;
+	unsigned int trip_id;
+	unsigned int usage;
+	unsigned long min;
+	unsigned long max;
+};
+
+/**
+ * struct __thermal_zone - internal representation of a thermal zone
+ * @mode: current thermal zone device mode (enabled/disabled)
+ * @passive_delay: polling interval while passive cooling is activated
+ * @polling_delay: zone polling interval
+ * @ntrips: number of trip points
+ * @trips: an array of trip points (0..ntrips - 1)
+ * @num_tbps: number of thermal bind params
+ * @tbps: an array of thermal bind params (0..num_tbps - 1)
+ * @sensor_data: sensor private data used while reading temperature and trend
+ * @get_temp: sensor callback to read temperature
+ * @get_trend: sensor callback to read temperature trend
+ */
+
+struct __thermal_zone {
+	enum thermal_device_mode mode;
+	int passive_delay;
+	int polling_delay;
+
+	/* trip data */
+	int ntrips;
+	struct __thermal_trip *trips;
+
+	/* cooling binding data */
+	int num_tbps;
+	struct __thermal_bind_params *tbps;
+
+	/* sensor interface */
+	void *sensor_data;
+	int (*get_temp)(void *, long *);
+	int (*get_trend)(void *, long *);
+};
+
+/***   DT thermal zone device callbacks   ***/
+
+static int of_thermal_get_temp(struct thermal_zone_device *tz,
+			       unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (!data->get_temp)
+		return -EINVAL;
+
+	return data->get_temp(data->sensor_data, temp);
+}
+
+static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
+				enum thermal_trend *trend)
+{
+	struct __thermal_zone *data = tz->devdata;
+	long dev_trend;
+	int r;
+
+	if (!data->get_trend)
+		return -EINVAL;
+
+	r = data->get_trend(data->sensor_data, &dev_trend);
+	if (r)
+		return r;
+
+	if (dev_trend > 0)
+		*trend = THERMAL_TREND_RAISING;
+	else if (dev_trend < 0)
+		*trend = THERMAL_TREND_DROPPING;
+	else
+		*trend = THERMAL_TREND_STABLE;
+
+	return 0;
+}
+
+static int of_thermal_bind(struct thermal_zone_device *thermal,
+			   struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to bind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_bind_cooling_device(thermal,
+						tbp->trip_id, cdev,
+						tbp->min,
+						tbp->max);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_unbind(struct thermal_zone_device *thermal,
+			     struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to unbind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_unbind_cooling_device(thermal,
+						tbp->trip_id, cdev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_get_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode *mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	*mode = data->mode;
+
+	return 0;
+}
+
+static int of_thermal_set_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	mutex_lock(&tz->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		tz->polling_delay = data->polling_delay;
+	else
+		tz->polling_delay = 0;
+
+	mutex_unlock(&tz->lock);
+
+	data->mode = mode;
+	thermal_zone_device_update(tz);
+
+	return 0;
+}
+
+static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
+				    enum thermal_trip_type *type)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*type = data->trips[trip].type;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*temp = data->trips[trip].temperature;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].temperature = temp;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long *hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*hyst = data->trips[trip].hysteresis;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].hysteresis = hyst;
+
+	return 0;
+}
+
+static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+	int i;
+
+	for (i = 0; i < data->ntrips; i++)
+		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = data->trips[i].temperature;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static struct thermal_zone_device_ops of_thermal_ops = {
+	.get_mode = of_thermal_get_mode,
+	.set_mode = of_thermal_set_mode,
+
+	.get_trip_type = of_thermal_get_trip_type,
+	.get_trip_temp = of_thermal_get_trip_temp,
+	.set_trip_temp = of_thermal_set_trip_temp,
+	.get_trip_hyst = of_thermal_get_trip_hyst,
+	.set_trip_hyst = of_thermal_set_trip_hyst,
+	.get_crit_temp = of_thermal_get_crit_temp,
+
+	.bind = of_thermal_bind,
+	.unbind = of_thermal_unbind,
+};
+
+/***   sensor API   ***/
+
+static struct thermal_zone_device *
+thermal_zone_of_add_sensor(struct device_node *zone,
+			   struct device_node *sensor, void *data,
+			   int (*get_temp)(void *, long *),
+			   int (*get_trend)(void *, long *))
+{
+	struct thermal_zone_device *tzd;
+	struct __thermal_zone *tz;
+
+	tzd = thermal_zone_get_zone_by_name(zone->name);
+	if (IS_ERR(tzd)) {
+		pr_err("zone not yet registered %s\n", zone->name);
+		return ERR_PTR(-EPROBE_DEFER);
+	}
+
+	tz = tzd->devdata;
+
+	mutex_lock(&tzd->lock);
+	tz->get_temp = get_temp;
+	tz->get_trend = get_trend;
+	tz->sensor_data = data;
+
+	tzd->ops->get_temp = of_thermal_get_temp;
+	tzd->ops->get_trend = of_thermal_get_trend;
+	mutex_unlock(&tzd->lock);
+
+	return tzd;
+}
+
+/**
+ * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @sensor_id: a sensor identifier, in case the sensor IP has more
+ *             than one sensors
+ * @data: a private pointer (owned by the caller) that will be passed
+ *        back, when a temperature reading is needed.
+ * @get_temp: a pointer to a function that reads the sensor temperature.
+ * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ *
+ * This function will search the list of thermal zones described in device
+ * tree and look for the zone that refer to the sensor device pointed by
+ * @dev->of_node as temperature providers. For the zone pointing to the
+ * sensor node, the sensor will be added to the DT thermal zone device.
+ *
+ * The thermal zone temperature is provided by the @get_temp function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * The thermal zone temperature trend is provided by the @get_trend function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * TODO:
+ * 01 - This function must enqueue the new sensor instead of using
+ * it as the only source of temperature values.
+ *
+ * 02 - There must be a way to match the sensor with all thermal zones
+ * that refer to it.
+ *
+ * Return: On success returns a valid struct thermal_zone_device,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	struct device_node *np, *child, *sensor_np;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		dev_err(dev, "unable to find thermal zones\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	if (!dev || !dev->of_node) {
+		dev_err(dev, "invalid device struct\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	sensor_np = dev->of_node;
+
+	for_each_child_of_node(np, child) {
+		struct of_phandle_args sensor_specs;
+		int ret;
+
+		/* For now, thermal framework supports only 1 sensor per zone */
+		ret = of_parse_phandle_with_args(child, "sensors",
+						 "#sensor-cells",
+						 0, &sensor_specs);
+		if (ret) {
+			dev_err(dev, "zone without sensors\n");
+			continue;
+		}
+
+		if (sensor_specs.args_count < 1) {
+			dev_err(dev, "must contain at least 1 parameter\n");
+			continue;
+		}
+
+		if (sensor_specs.np == sensor_np &&
+		    sensor_specs.args[0] == sensor_id) {
+			of_node_put(np);
+			return thermal_zone_of_add_sensor(child, sensor_np,
+							  data,
+							  get_temp,
+							  get_trend);
+		}
+	}
+	of_node_put(np);
+
+	return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
+
+/**
+ * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
+ *
+ * This function removes the sensor callbacks and private data from the
+ * thermal zone device registered with thermal_zone_of_sensor_register()
+ * API. It will also silent the zone by remove the .get_temp() and .get_trend()
+ * thermal zone device callbacks.
+ *
+ * TODO: When the support to several sensors per zone is added, this
+ * function must search the sensor list based on @dev parameter.
+ *
+ */
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tzd)
+{
+	struct __thermal_zone *tz = tzd->devdata;
+
+	/* no __thermal_zone, nothing to be done */
+	if (!tz)
+		return;
+
+	mutex_lock(&tzd->lock);
+	tzd->ops->get_temp = NULL;
+	tzd->ops->get_trend = NULL;
+
+	tz->get_temp = NULL;
+	tz->get_trend = NULL;
+	tz->sensor_data = NULL;
+	mutex_unlock(&tzd->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
+
+/***   functions parsing device tree nodes   ***/
+
+/**
+ * thermal_of_populate_bind_params - parse and fill cooling attachment data
+ * @np: DT node containing a cooling-attachment node
+ * @__tbp: data structure to be filled with cooling attachment info
+ * @trips: array of thermal zone trip points
+ * @ntrips: number of trip points inside trips.
+ *
+ * This function parses a cooling-attachment type of node represented by
+ * @np parameter and fills the read data into @__tbp data structure.
+ * It needs the already parsed array of trip points of the thermal zone
+ * in consideration.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_bind_params(struct device_node *np,
+					   struct __thermal_bind_params *__tbp,
+					   struct __thermal_trip *trips,
+					   int ntrips)
+{
+	struct of_phandle_args cooling_spec;
+	struct device_node *trip;
+	int ret, i;
+	u32 prop;
+
+	/* Default weight. Usage is optional */
+	__tbp->usage = 0;
+	ret = of_property_read_u32(np, "usage", &prop);
+	if (ret == 0)
+		__tbp->usage = prop;
+
+	trip = of_parse_phandle(np, "trip", 0);
+	if (!trip) {
+		pr_err("missing trip property\n");
+		return -ENODEV;
+	}
+
+	/* match using device_node */
+	for (i = 0; i < ntrips; i++)
+		if (trip == trips[i].np) {
+			__tbp->trip_id = i;
+			break;
+		}
+
+	if (i == ntrips) {
+		ret = -ENODEV;
+		goto end;
+	}
+
+	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
+					 0, &cooling_spec);
+	if (ret < 0) {
+		pr_err("missing cooling_device property\n");
+		goto end;
+	}
+	__tbp->cooling_device = cooling_spec.np;
+	if (cooling_spec.args_count >= 2) { /* at least min and max */
+		__tbp->min = cooling_spec.args[0];
+		__tbp->max = cooling_spec.args[1];
+	} else {
+		pr_err("wrong reference to cooling device, missing limits\n");
+	}
+
+end:
+	of_node_put(trip);
+
+	return ret;
+}
+
+/**
+ * thermal_of_populate_trip - parse and fill one trip point data
+ * @np: DT node containing a trip point node
+ * @trip: trip point data structure to be filled up
+ *
+ * This function parses a trip point type of node represented by
+ * @np parameter and fills the read data into @trip data structure.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_trip(struct device_node *np,
+				    struct __thermal_trip *trip)
+{
+	int prop;
+	int ret;
+
+	ret = of_property_read_u32(np, "temperature", &prop);
+	if (ret < 0) {
+		pr_err("missing temperature property\n");
+		return ret;
+	}
+	trip->temperature = prop;
+
+	ret = of_property_read_u32(np, "hysteresis", &prop);
+	if (ret < 0) {
+		pr_err("missing hysteresis property\n");
+		return ret;
+	}
+	trip->hysteresis = prop;
+
+	ret = of_property_read_u32(np, "type", &prop);
+	if (ret < 0) {
+		pr_err("missing type property\n");
+		return ret;
+	}
+	trip->type = prop;
+
+	/* Required for cooling attachment matching */
+	trip->np = np;
+
+	return 0;
+}
+
+/**
+ * thermal_of_build_thermal_zone - parse and fill one thermal zone data
+ * @np: DT node containing a thermal zone node
+ *
+ * This function parses a thermal zone type of node represented by
+ * @np parameter and fills the read data into a __thermal_zone data structure
+ * and return this pointer.
+ *
+ * Return: On success returns a valid struct __thermal_zone,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+static struct __thermal_zone *
+thermal_of_build_thermal_zone(struct device_node *np)
+{
+	struct device_node *child, *gchild;
+	struct __thermal_zone *tz;
+	int ret, i;
+	u32 prop;
+
+	if (!np) {
+		pr_err("no thermal zone np\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
+	if (!tz) {
+		pr_err("not enough memory for thermal of zone\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(np, "passive-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing passive_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->passive_delay = prop;
+
+	ret = of_property_read_u32(np, "polling-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing polling_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->polling_delay = prop;
+
+	/* trips */
+	child = of_get_child_by_name(np, "trips");
+
+	/* No trips provided */
+	if (!child)
+		goto finish;
+
+	tz->ntrips = of_get_child_count(child);
+	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
+	if (!tz->trips)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_trip(gchild, &tz->trips[i++]);
+
+	of_node_put(child);
+
+	/* cooling-attachments */
+	child = of_get_child_by_name(np, "cooling-attachments");
+
+	/* cooling-attachments provided */
+	if (!child)
+		goto finish;
+
+	tz->num_tbps = of_get_child_count(child);
+	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
+	if (!tz->tbps)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
+						tz->trips, tz->ntrips);
+
+finish:
+	tz->mode = THERMAL_DEVICE_DISABLED;
+
+	return tz;
+}
+
+/**
+ * of_parse_thermal_zones - parse device tree thermal data
+ *
+ * Initialization function that can be called by machine initialization
+ * code to parse thermal data and populate the thermal framework
+ * with hardware thermal zones info. This function only parses thermal zones.
+ * Cooling devices and sensor devices nodes are supposed to be parsed
+ * by their respective drivers.
+ *
+ * Return: 0 on success, proper error code otherwise
+ *
+ */
+int __init of_parse_thermal_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+	struct thermal_zone_device_ops *ops;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return 0;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+		struct thermal_zone_params *tzp;
+
+		tz = thermal_of_build_thermal_zone(child);
+		if (IS_ERR(tz)) {
+			pr_err("failed to build thermal zone %ld\n",
+			       PTR_ERR(tz));
+			return 0;
+		}
+
+		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal ops\n");
+			return 0;
+		}
+		memcpy(ops, &of_thermal_ops, sizeof(*ops));
+
+		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal zone params\n");
+			return 0;
+		}
+		/* No hwmon because there might be hwmon drivers registering */
+		tzp->no_hwmon = true;
+
+		zone = thermal_zone_device_register(child->name, tz->ntrips,
+						    0, tz,
+						    ops, tzp,
+						    tz->passive_delay,
+						    tz->polling_delay);
+		if (IS_ERR(zone))
+			pr_err("Failed to build %s zone %ld\n", child->name,
+			       PTR_ERR(zone));
+	}
+	return 0;
+}
+
+/**
+ * of_thermal_destroy_zones - remove all zones parsed and allocated resources
+ *
+ * Finds all zones parsed and added to the thermal framework and remove them
+ * from the system, together with their resources.
+ *
+ */
+void __exit of_thermal_destroy_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+
+		zone = thermal_zone_get_zone_by_name(child->name);
+		if (IS_ERR(zone))
+			continue;
+
+		thermal_zone_device_unregister(zone);
+		kfree(zone->tzp);
+		kfree(zone->ops);
+		tz = zone->devdata;
+		kfree(tz->tbps);
+		kfree(tz->trips);
+		kfree(tz);
+	}
+}
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 8a94300..a733241 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
  */
 struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int trips, int mask, void *devdata,
-	const struct thermal_zone_device_ops *ops,
+	struct thermal_zone_device_ops *ops,
 	const struct thermal_zone_params *tzp,
 	int passive_delay, int polling_delay)
 {
@@ -1751,8 +1751,14 @@ static int __init thermal_init(void)
 	if (result)
 		goto unregister_class;
 
+	result = of_parse_thermal_zones();
+	if (result)
+		goto exit_netlink;
+
 	return 0;
 
+exit_netlink:
+	genetlink_exit();
 unregister_governors:
 	thermal_unregister_governors();
 unregister_class:
@@ -1768,6 +1774,7 @@ error:
 
 static void __exit thermal_exit(void)
 {
+	of_thermal_destroy_zones();
 	genetlink_exit();
 	class_unregister(&thermal_class);
 	thermal_unregister_governors();
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 7cf2f66..3db339f 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
 static inline void thermal_gov_user_space_unregister(void) {}
 #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
 
+/* device tree support */
+#ifdef CONFIG_THERMAL_OF
+int of_parse_thermal_zones(void);
+void of_thermal_destroy_zones(void);
+#else
+static inline int of_parse_thermal_zones(void) { return 0; }
+static inline void of_thermal_destroy_zones(void) { }
+#endif
+
 #endif /* __THERMAL_CORE_H__ */
diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h
new file mode 100644
index 0000000..6dd6ccd
--- /dev/null
+++ b/include/dt-bindings/thermal/thermal.h
@@ -0,0 +1,27 @@
+/*
+ * This header provides constants for most thermal bindings.
+ *
+ * Copyright (C) 2013 Texas Instruments
+ *	Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
+ *
+ * GPLv2 only
+ */
+
+#ifndef _DT_BINDINGS_THERMAL_THERMAL_H
+#define _DT_BINDINGS_THERMAL_THERMAL_H
+
+/*
+ * Here are the thermal trip types. This must
+ * match with enum thermal_trip_type at
+ * include/linux/thermal.h
+ */
+#define THERMAL_TRIP_ACTIVE		0
+#define THERMAL_TRIP_PASSIVE		1
+#define THERMAL_TRIP_HOT		2
+#define THERMAL_TRIP_CRITICAL		3
+
+/* On cooling devices upper and lower limits */
+#define THERMAL_NO_LIMIT		(-1UL)
+
+#endif
+
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index b268d3c..b780c5b 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -143,6 +143,7 @@ struct thermal_cooling_device {
 	int id;
 	char type[THERMAL_NAME_LENGTH];
 	struct device device;
+	struct device_node *np;
 	void *devdata;
 	const struct thermal_cooling_device_ops *ops;
 	bool updated; /* true if the cooling device does not need update */
@@ -172,7 +173,7 @@ struct thermal_zone_device {
 	int emul_temperature;
 	int passive;
 	unsigned int forced_passive;
-	const struct thermal_zone_device_ops *ops;
+	struct thermal_zone_device_ops *ops;
 	const struct thermal_zone_params *tzp;
 	struct thermal_governor *governor;
 	struct list_head thermal_instances;
@@ -242,8 +243,31 @@ struct thermal_genl_event {
 };
 
 /* Function declarations */
+#ifdef CONFIG_THERMAL_OF
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *));
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz);
+#else
+static inline struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	return NULL;
+}
+
+static inline
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz)
+{
+}
+
+#endif
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
-		void *, const struct thermal_zone_device_ops *,
+		void *, struct thermal_zone_device_ops *,
 		const struct thermal_zone_params *, int, int);
 void thermal_zone_device_unregister(struct thermal_zone_device *);
 
-- 
1.8.2.1.342.gfa7285d

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[PATCHv2 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

This patch introduces a device tree bindings for
describing the hardware thermal behavior and limits.
Also a parser to read and interpret the data and feed
it in the thermal framework is presented.

This patch introduces a thermal data parser for device
tree. The parsed data is used to build thermal zones
and thermal binding parameters. The output data
can then be used to deploy thermal policies.

This patch adds also documentation regarding this
API and how to define tree nodes to use
this infrastructure.

Note that, in order to be able to have control
on the sensor registration on the DT thermal zone,
it was required to allow changing the thermal zone
.get_temp callback. For this reason, this patch
also removes the 'const' modifier from the .ops
field of thermal zone devices.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
 drivers/thermal/Kconfig                            |  13 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/of-thermal.c                       | 753 +++++++++++++++++++++
 drivers/thermal/thermal_core.c                     |   9 +-
 drivers/thermal/thermal_core.h                     |   9 +
 include/dt-bindings/thermal/thermal.h              |  27 +
 include/linux/thermal.h                            |  28 +-
 8 files changed, 1335 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
 create mode 100644 drivers/thermal/of-thermal.c
 create mode 100644 include/dt-bindings/thermal/thermal.h
---

Hi all,

As per Guenter's request, I changed this code to fail silently while
registering sensor drivers.

Cheers,

Eduardo

diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
new file mode 100644
index 0000000..6664533
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/thermal.txt
@@ -0,0 +1,498 @@
+* Thermal Framework Device Tree descriptor
+
+Generic binding to provide a way of defining hardware thermal
+structure using device tree. A thermal structure includes thermal
+zones and their components, such as trip points, polling intervals,
+sensors and cooling devices binding descriptors.
+
+The target of device tree thermal descriptors is to describe only
+the hardware thermal aspects, not how the system must control or which
+algorithm or policy must be taken in place.
+
+There are five types of nodes involved to describe thermal bindings:
+- sensors: used to describe the device source of temperature sensing;
+- cooling devices: used to describe devices source of power dissipation control;
+- trip points: used to describe points in temperature domain defined to
+make the system aware of hardware limits;
+- cooling attachments: used to describe links between trip points and
+cooling devices;
+- thermal zones: used to describe thermal data within the hardware;
+
+It follows a description of each type of these device tree nodes.
+
+* Sensor devices
+
+Sensor devices are nodes providing temperature sensing capabilities on thermal
+zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
+providing temperature data to thermal zones. Temperature sensor devices may
+control one or more internal sensors.
+
+Required property:
+- #sensor-cells:	Used to provide sensor device specific information
+			while referring to it. Must be at least 1, in order
+			to identify uniquely the sensor instances within
+			the IC. See thermal zone binding for more details
+			on how consumers refer to sensor devices.
+
+* Cooling device nodes
+
+Cooling devices are nodes providing control on power dissipation. There
+are essentially two ways to provide control on power dissipation. First
+is by means of regulating device performance, which is known as passive
+cooling. Second is by means of activating devices in order to remove
+the dissipated heat, which is known as active cooling, e.g. regulating
+fan speeds. In both cases, cooling devices shall have a way to determine
+the level of cooling.
+
+Required property:
+- cooling-min-level:	A unsigned integer indicating the smallest
+			cooling level accepted. Typically 0.
+- cooling-max-level:	An unsigned integer indicating the largest
+			cooling level accepted.
+- #cooling-cells:	Used to provide cooling device specific information
+			while referring to it. Must be at least 2, in order
+			to specify minimum and maximum cooling level used
+			in the reference. See Cooling device attachments section
+			below for more details on how consumers refer to
+			cooling devices.
+
+* Trip points
+
+The trip node is a node to describe a point in the temperature domain
+in which the system takes an action. This node describes just the point,
+not the action.
+
+Required properties:
+- temperature:		the trip temperature level, in milliCelsius.
+- hysteresis:		a (low) hysteresis value on 'temperature'. This is a
+			relative value, in milliCelsius.
+- type:			the trip type. Here is the type mapping:
+	THERMAL_TRIP_ACTIVE	0:	A trip point to enable active cooling
+	THERMAL_TRIP_PASSIVE	1:	A trip point to enable passive cooling
+	THERMAL_TRIP_HOT	2:	A trip point to notify emergency
+	THERMAL_TRIP_CRITICAL	3:	Hardware not reliable.
+
+Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
+
+* Cooling device attachments
+
+The cooling device attachments node is a node to describe how cooling devices
+get assigned to trip points of the zone. The cooling devices are expected
+to be loaded in the target system.
+
+Required properties:
+- cooling-device:	A phandle of a cooling device with its parameters,
+			referring to which cooling device is used in this
+			binding. The required parameters are: the minimum
+			cooling level and the maximum cooling level used
+			in this attach.
+- trip:			A phandle of a trip point node within the same thermal
+			zone.
+
+Optional property:
+- contribution:		The cooling contribution to the thermal zone of the
+			referred cooling device at the referred trip point.
+			The contribution is a value from 0 to 100. The sum
+			of all cooling contributions within a thermal zone
+			must never exceed 100.
+
+Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
+limit parameters means:
+(i)   - minimum level allowed for minimum cooling level used in the reference.
+(ii)  - maximum level allowed for maximum cooling level used in the reference.
+Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
+
+* Thermal zones
+
+The thermal-zone node is the node containing all the required info
+for describing a thermal zone, including its cdev bindings. The thermal_zone
+node must contain, apart from its own properties, one node containing
+trip nodes and one node containing all the zone cooling attachments.
+
+Required properties:
+- passive-delay:	The maximum number of milliseconds to wait between polls
+			when performing passive cooling.
+- polling-delay:	The maximum number of milliseconds to wait between polls
+			when checking this thermal zone.
+- sensors:		A list of sensor phandles and their parameters. The
+			required parameter is the sensor id, in order to
+			identify internal sensors when the sensor IC features
+			several sensing units.
+- trips:		A sub-node containing several trip point nodes required
+			to describe the thermal zone.
+- cooling-attachments	A sub-node containing several cooling device attaches
+			nodes, used to describe the relation between trips
+			and cooling devices.
+
+Optional property:
+- coefficients:		An array of integers (one signed cell) containing
+			coefficients to compose a linear relation between
+			the sensors described in the sensors property.
+			Coefficients defaults to 1, in case this property
+			is not specified. A simple linear polynomial is used:
+			Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
+
+			The coefficients are ordered and they match with sensors
+			by means of sensor ID. Additional coefficients are
+			interpreted as constant offsets.
+
+Note: The delay properties are bound to the maximum dT/dt (temperature
+derivative over time) in two situations for a thermal zone:
+(i)  - when active cooling is activated (passive-delay); and
+(ii) - when the zone just needs to be monitored (polling-delay).
+The maximum dT/dt is highly bound to hardware power consumption and dissipation
+capability.
+
+* Examples
+
+Below are several examples on how to use thermal data descriptors
+using device tree bindings:
+
+(a) - CPU thermal zone
+
+The CPU thermal zone example below describes how to setup one thermal zone
+using one single sensor as temperature source and many cooling devices and
+power dissipation control sources.
+
+#include <dt-bindings/thermal/thermal.h>
+
+cpus {
+	cpu0: cpu@0 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <3>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+	...
+};
+
+&i2c1 {
+	...
+	fan0: fan@0x48 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <9>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+                cpu-alert0: cpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_ACTIVE>;
+                };
+                cpu-alert1: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-alert0>;
+			cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
+		};
+		attach1 {
+			trip = <&cpu-alert1>;
+			cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
+		};
+		attach2 {
+			trip = <&cpu-alert1>;
+			cooling-device =
+				<&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
+		};
+	};
+};
+
+In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
+the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
+via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
+zone 'cpu-thermal' using its cooling levels from its minimum to 4, when it
+reaches trip point 'cpu-alert0' at 90C, as an example of active cooling. The
+same cooling device is used at 'cpu-alert1', but from 5 to its maximum level.
+The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
+passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
+which is a trip point at 100C.
+
+(b) - IC with several internal sensors
+
+The example below describes how to deploy several thermal zones based off a
+single sensor IC, assuming it has several internal sensors. This is a common
+case on SoC designs with several internal IPs that may need different thermal
+requirements, and thus may have their own sensor to monitor or detect internal
+hotspots in their silicon.
+
+#include <dt-bindings/thermal/thermal.h>
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                cpu-alert: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+gpu-thermal: gpu-thermal {
+	passive-delay = <120>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     1>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                gpu-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                gpu-crit: gpu-crit {
+                        temperature = <105000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+dsp-thermal: dsp-thermal {
+	passive-delay = <50>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     2>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                dsp-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                dsp-crit: gpu-crit {
+                        temperature = <135000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+In the example above there is one bandgap IC which has the capability to
+monitor three sensors. The hardware has been designed so that sensors are
+placed on different places in the DIE to monitor different temperature
+hotspots: one for CPU thermal zone, one for GPU thermal zone and the
+other to monitor a DSP thermal zone.
+
+Thus, there is a need to assign each sensor provided by the bandgap IC
+to different thermal zones. This is achieved by means of using the
+#sensor-cells property and using the first parameter as sensor ID.
+In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
+bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
+is used to monitor DSP thermal zone. Each zone may be uncorrelated,
+having its own dT/dt requirements, trips and cooling attachments.
+
+
+(c) - Several sensors within one single thermal zone
+
+The example below illustrates how to use more than one sensor within
+one thermal zone.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc: sensor@0x49 {
+		...
+		#sensor-cells = <1>;
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0	0>,
+		  <&adc		0>;
+
+		/* hotspot = 100 * bandgap - 120 * adc + 484 */
+	coefficients = 		<100	-120	484>;
+
+        trips {
+		...
+        };
+
+	cooling-attachments {
+		...
+	};
+};
+
+In some cases, there is a need to use more than one sensor to extrapolate
+a thermal hotspot in the silicon. The above example illustrate this situation.
+For instance, it may be the case that a sensor external to CPU IP may be place
+close to CPU hotspot and together with internal CPU sensor, it is used
+to determine the hotspot. The hyppotetical extrapolation rule would be:
+		hotspot = 100 * bandgap - 120 * adc + 484
+
+The same idea can be used to add fixed offset:
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+		hotspot = 1 * adc + 6000
+
+In the above equation, the hotspot is always 6C higher than what is read
+from the sensor ADC. The binding would be then:
+		/* sensor       ID */
+        sensors =  <&adc	0>;
+
+		/* hotspot = 1 * adc + 6000 */
+	coefficients = 		<1	6000>;
+
+(d) - Board thermal
+
+The board thermal example below illustrates how to setup one thermal zone
+with many sensors and many cooling devices.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc-dummy: sensor@0x50 {
+		...
+		#sensor-cells = <1>; /* sensor internal ID */
+	};
+};
+
+batt-thermal {
+	passive-delay = <500>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+	/* sensor       ID */
+	sensors = <&adc-dummy     4>;
+
+	trips {
+		...
+	};
+
+	cooling-attachments {
+		...
+	};
+};
+
+board-thermal: board-thermal {
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+		/* sensor       ID */
+	sensors = <&adc-dummy     0>,
+		  <&adc-dummy     1>,
+		  <&adc-dymmy     2>;
+			/*
+			 * An array of coefficients describing the sensor
+			 * linear relation. E.g.:
+			 * z = c1*x1 + c2*x2 + c3*x3
+			 */
+	coefficients =		<1200	-345	890>;
+
+	trips {
+		/* Trips are based on resulting linear equation */
+		cpu-trip: cpu-trip {
+			temperature = <60000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		gpu-trip: gpu-trip {
+			temperature = <55000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		}
+		lcd-trip: lcp-trip {
+			temperature = <53000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		crit-trip: crit-trip {
+			temperature = <68000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_CRITICAL>;
+		};
+	};
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-trip>;
+			cooling-device = <&cpu0 0 2>;
+			contribution = <55>;
+		};
+		attach1 {
+			trip = <&gpu-trip>;
+			cooling-device = <&gpu0 0 2>;
+			contribution = <20>;
+		};
+		attach2 {
+			trip = <&lcd-trip>;
+			cooling-device = <&lcd0 5 10>;
+			contribution = <15>;
+		};
+	};
+};
+
+The above example is a mix of previous examples, a sensor IP with several internal
+sensors used to monitor different zones, one of them is composed by several sensors and
+with different cooling devices.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index dbfc390..dd81eb8 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -29,6 +29,19 @@ config THERMAL_HWMON
 	  Say 'Y' here if you want all thermal sensors to
 	  have hwmon sysfs interface too.
 
+config THERMAL_OF
+	bool
+	prompt "APIs to parse thermal data out of device tree"
+	depends on OF
+	default y
+	help
+	  This options provides helpers to add the support to
+	  read and parse thermal data definitions out of the
+	  device tree blob.
+
+	  Say 'Y' here if you need to build thermal infrastructure
+	  based on device tree.
+
 choice
 	prompt "Default Thermal governor"
 	default THERMAL_DEFAULT_GOV_STEP_WISE
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 584b363..4b03956 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
 
 # interface to/from other layers providing sensors
 thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
+thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
 
 # governors
 thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
new file mode 100644
index 0000000..857d40c
--- /dev/null
+++ b/drivers/thermal/of-thermal.c
@@ -0,0 +1,753 @@
+/*
+ *  of-thermal.c - Generic Thermal Management device tree support.
+ *
+ *  Copyright (C) 2013 Texas Instruments
+ *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/string.h>
+
+/***   Private data structures to represent thermal device tree data ***/
+
+/**
+ * struct __thermal_trip - representation of a point in temperature domain
+ * @np: pointer to struct device_node that this trip point was created from
+ * @temperature: temperature value in miliCelsius
+ * @hysteresis: relative hysteresis in miliCelsius
+ * @type: trip point type
+ */
+
+struct __thermal_trip {
+	struct device_node *np;
+	unsigned long int temperature;
+	unsigned long int hysteresis;
+	enum thermal_trip_type type;
+};
+
+/**
+ * struct __thermal_bind_param - a match between trip and cooling device
+ * @cooling_device: a pointer to identify the referred cooling device
+ * @trip_id: the trip point index
+ * @usage: the percentage (from 0 to 100) of cooling contribution
+ * @min: minimum cooling level used at this trip point
+ * @max: maximum cooling level used at this trip point
+ */
+
+struct __thermal_bind_params {
+	struct device_node *cooling_device;
+	unsigned int trip_id;
+	unsigned int usage;
+	unsigned long min;
+	unsigned long max;
+};
+
+/**
+ * struct __thermal_zone - internal representation of a thermal zone
+ * @mode: current thermal zone device mode (enabled/disabled)
+ * @passive_delay: polling interval while passive cooling is activated
+ * @polling_delay: zone polling interval
+ * @ntrips: number of trip points
+ * @trips: an array of trip points (0..ntrips - 1)
+ * @num_tbps: number of thermal bind params
+ * @tbps: an array of thermal bind params (0..num_tbps - 1)
+ * @sensor_data: sensor private data used while reading temperature and trend
+ * @get_temp: sensor callback to read temperature
+ * @get_trend: sensor callback to read temperature trend
+ */
+
+struct __thermal_zone {
+	enum thermal_device_mode mode;
+	int passive_delay;
+	int polling_delay;
+
+	/* trip data */
+	int ntrips;
+	struct __thermal_trip *trips;
+
+	/* cooling binding data */
+	int num_tbps;
+	struct __thermal_bind_params *tbps;
+
+	/* sensor interface */
+	void *sensor_data;
+	int (*get_temp)(void *, long *);
+	int (*get_trend)(void *, long *);
+};
+
+/***   DT thermal zone device callbacks   ***/
+
+static int of_thermal_get_temp(struct thermal_zone_device *tz,
+			       unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (!data->get_temp)
+		return -EINVAL;
+
+	return data->get_temp(data->sensor_data, temp);
+}
+
+static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
+				enum thermal_trend *trend)
+{
+	struct __thermal_zone *data = tz->devdata;
+	long dev_trend;
+	int r;
+
+	if (!data->get_trend)
+		return -EINVAL;
+
+	r = data->get_trend(data->sensor_data, &dev_trend);
+	if (r)
+		return r;
+
+	if (dev_trend > 0)
+		*trend = THERMAL_TREND_RAISING;
+	else if (dev_trend < 0)
+		*trend = THERMAL_TREND_DROPPING;
+	else
+		*trend = THERMAL_TREND_STABLE;
+
+	return 0;
+}
+
+static int of_thermal_bind(struct thermal_zone_device *thermal,
+			   struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to bind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_bind_cooling_device(thermal,
+						tbp->trip_id, cdev,
+						tbp->min,
+						tbp->max);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_unbind(struct thermal_zone_device *thermal,
+			     struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to unbind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_unbind_cooling_device(thermal,
+						tbp->trip_id, cdev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_get_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode *mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	*mode = data->mode;
+
+	return 0;
+}
+
+static int of_thermal_set_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	mutex_lock(&tz->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		tz->polling_delay = data->polling_delay;
+	else
+		tz->polling_delay = 0;
+
+	mutex_unlock(&tz->lock);
+
+	data->mode = mode;
+	thermal_zone_device_update(tz);
+
+	return 0;
+}
+
+static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
+				    enum thermal_trip_type *type)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*type = data->trips[trip].type;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*temp = data->trips[trip].temperature;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].temperature = temp;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long *hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*hyst = data->trips[trip].hysteresis;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].hysteresis = hyst;
+
+	return 0;
+}
+
+static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+	int i;
+
+	for (i = 0; i < data->ntrips; i++)
+		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = data->trips[i].temperature;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static struct thermal_zone_device_ops of_thermal_ops = {
+	.get_mode = of_thermal_get_mode,
+	.set_mode = of_thermal_set_mode,
+
+	.get_trip_type = of_thermal_get_trip_type,
+	.get_trip_temp = of_thermal_get_trip_temp,
+	.set_trip_temp = of_thermal_set_trip_temp,
+	.get_trip_hyst = of_thermal_get_trip_hyst,
+	.set_trip_hyst = of_thermal_set_trip_hyst,
+	.get_crit_temp = of_thermal_get_crit_temp,
+
+	.bind = of_thermal_bind,
+	.unbind = of_thermal_unbind,
+};
+
+/***   sensor API   ***/
+
+static struct thermal_zone_device *
+thermal_zone_of_add_sensor(struct device_node *zone,
+			   struct device_node *sensor, void *data,
+			   int (*get_temp)(void *, long *),
+			   int (*get_trend)(void *, long *))
+{
+	struct thermal_zone_device *tzd;
+	struct __thermal_zone *tz;
+
+	tzd = thermal_zone_get_zone_by_name(zone->name);
+	if (IS_ERR(tzd))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	tz = tzd->devdata;
+
+	mutex_lock(&tzd->lock);
+	tz->get_temp = get_temp;
+	tz->get_trend = get_trend;
+	tz->sensor_data = data;
+
+	tzd->ops->get_temp = of_thermal_get_temp;
+	tzd->ops->get_trend = of_thermal_get_trend;
+	mutex_unlock(&tzd->lock);
+
+	return tzd;
+}
+
+/**
+ * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @sensor_id: a sensor identifier, in case the sensor IP has more
+ *             than one sensors
+ * @data: a private pointer (owned by the caller) that will be passed
+ *        back, when a temperature reading is needed.
+ * @get_temp: a pointer to a function that reads the sensor temperature.
+ * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ *
+ * This function will search the list of thermal zones described in device
+ * tree and look for the zone that refer to the sensor device pointed by
+ * @dev->of_node as temperature providers. For the zone pointing to the
+ * sensor node, the sensor will be added to the DT thermal zone device.
+ *
+ * The thermal zone temperature is provided by the @get_temp function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * The thermal zone temperature trend is provided by the @get_trend function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * TODO:
+ * 01 - This function must enqueue the new sensor instead of using
+ * it as the only source of temperature values.
+ *
+ * 02 - There must be a way to match the sensor with all thermal zones
+ * that refer to it.
+ *
+ * Return: On success returns a valid struct thermal_zone_device,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	struct device_node *np, *child, *sensor_np;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np)
+		return ERR_PTR(-ENODEV);
+
+	if (!dev || !dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	sensor_np = dev->of_node;
+
+	for_each_child_of_node(np, child) {
+		struct of_phandle_args sensor_specs;
+		int ret;
+
+		/* For now, thermal framework supports only 1 sensor per zone */
+		ret = of_parse_phandle_with_args(child, "sensors",
+						 "#sensor-cells",
+						 0, &sensor_specs);
+		if (ret)
+			continue;
+
+		if (sensor_specs.args_count < 1)
+			continue;
+
+		if (sensor_specs.np == sensor_np &&
+		    sensor_specs.args[0] == sensor_id) {
+			of_node_put(np);
+			return thermal_zone_of_add_sensor(child, sensor_np,
+							  data,
+							  get_temp,
+							  get_trend);
+		}
+	}
+	of_node_put(np);
+
+	return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
+
+/**
+ * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
+ *
+ * This function removes the sensor callbacks and private data from the
+ * thermal zone device registered with thermal_zone_of_sensor_register()
+ * API. It will also silent the zone by remove the .get_temp() and .get_trend()
+ * thermal zone device callbacks.
+ *
+ * TODO: When the support to several sensors per zone is added, this
+ * function must search the sensor list based on @dev parameter.
+ *
+ */
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tzd)
+{
+	struct __thermal_zone *tz = tzd->devdata;
+
+	/* no __thermal_zone, nothing to be done */
+	if (!tz)
+		return;
+
+	mutex_lock(&tzd->lock);
+	tzd->ops->get_temp = NULL;
+	tzd->ops->get_trend = NULL;
+
+	tz->get_temp = NULL;
+	tz->get_trend = NULL;
+	tz->sensor_data = NULL;
+	mutex_unlock(&tzd->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
+
+/***   functions parsing device tree nodes   ***/
+
+/**
+ * thermal_of_populate_bind_params - parse and fill cooling attachment data
+ * @np: DT node containing a cooling-attachment node
+ * @__tbp: data structure to be filled with cooling attachment info
+ * @trips: array of thermal zone trip points
+ * @ntrips: number of trip points inside trips.
+ *
+ * This function parses a cooling-attachment type of node represented by
+ * @np parameter and fills the read data into @__tbp data structure.
+ * It needs the already parsed array of trip points of the thermal zone
+ * in consideration.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_bind_params(struct device_node *np,
+					   struct __thermal_bind_params *__tbp,
+					   struct __thermal_trip *trips,
+					   int ntrips)
+{
+	struct of_phandle_args cooling_spec;
+	struct device_node *trip;
+	int ret, i;
+	u32 prop;
+
+	/* Default weight. Usage is optional */
+	__tbp->usage = 0;
+	ret = of_property_read_u32(np, "usage", &prop);
+	if (ret == 0)
+		__tbp->usage = prop;
+
+	trip = of_parse_phandle(np, "trip", 0);
+	if (!trip) {
+		pr_err("missing trip property\n");
+		return -ENODEV;
+	}
+
+	/* match using device_node */
+	for (i = 0; i < ntrips; i++)
+		if (trip == trips[i].np) {
+			__tbp->trip_id = i;
+			break;
+		}
+
+	if (i == ntrips) {
+		ret = -ENODEV;
+		goto end;
+	}
+
+	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
+					 0, &cooling_spec);
+	if (ret < 0) {
+		pr_err("missing cooling_device property\n");
+		goto end;
+	}
+	__tbp->cooling_device = cooling_spec.np;
+	if (cooling_spec.args_count >= 2) { /* at least min and max */
+		__tbp->min = cooling_spec.args[0];
+		__tbp->max = cooling_spec.args[1];
+	} else {
+		pr_err("wrong reference to cooling device, missing limits\n");
+	}
+
+end:
+	of_node_put(trip);
+
+	return ret;
+}
+
+/**
+ * thermal_of_populate_trip - parse and fill one trip point data
+ * @np: DT node containing a trip point node
+ * @trip: trip point data structure to be filled up
+ *
+ * This function parses a trip point type of node represented by
+ * @np parameter and fills the read data into @trip data structure.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_trip(struct device_node *np,
+				    struct __thermal_trip *trip)
+{
+	int prop;
+	int ret;
+
+	ret = of_property_read_u32(np, "temperature", &prop);
+	if (ret < 0) {
+		pr_err("missing temperature property\n");
+		return ret;
+	}
+	trip->temperature = prop;
+
+	ret = of_property_read_u32(np, "hysteresis", &prop);
+	if (ret < 0) {
+		pr_err("missing hysteresis property\n");
+		return ret;
+	}
+	trip->hysteresis = prop;
+
+	ret = of_property_read_u32(np, "type", &prop);
+	if (ret < 0) {
+		pr_err("missing type property\n");
+		return ret;
+	}
+	trip->type = prop;
+
+	/* Required for cooling attachment matching */
+	trip->np = np;
+
+	return 0;
+}
+
+/**
+ * thermal_of_build_thermal_zone - parse and fill one thermal zone data
+ * @np: DT node containing a thermal zone node
+ *
+ * This function parses a thermal zone type of node represented by
+ * @np parameter and fills the read data into a __thermal_zone data structure
+ * and return this pointer.
+ *
+ * Return: On success returns a valid struct __thermal_zone,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+static struct __thermal_zone *
+thermal_of_build_thermal_zone(struct device_node *np)
+{
+	struct device_node *child, *gchild;
+	struct __thermal_zone *tz;
+	int ret, i;
+	u32 prop;
+
+	if (!np) {
+		pr_err("no thermal zone np\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
+	if (!tz) {
+		pr_err("not enough memory for thermal of zone\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(np, "passive-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing passive_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->passive_delay = prop;
+
+	ret = of_property_read_u32(np, "polling-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing polling_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->polling_delay = prop;
+
+	/* trips */
+	child = of_get_child_by_name(np, "trips");
+
+	/* No trips provided */
+	if (!child)
+		goto finish;
+
+	tz->ntrips = of_get_child_count(child);
+	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
+	if (!tz->trips)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_trip(gchild, &tz->trips[i++]);
+
+	of_node_put(child);
+
+	/* cooling-attachments */
+	child = of_get_child_by_name(np, "cooling-attachments");
+
+	/* cooling-attachments provided */
+	if (!child)
+		goto finish;
+
+	tz->num_tbps = of_get_child_count(child);
+	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
+	if (!tz->tbps)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
+						tz->trips, tz->ntrips);
+
+finish:
+	tz->mode = THERMAL_DEVICE_DISABLED;
+
+	return tz;
+}
+
+/**
+ * of_parse_thermal_zones - parse device tree thermal data
+ *
+ * Initialization function that can be called by machine initialization
+ * code to parse thermal data and populate the thermal framework
+ * with hardware thermal zones info. This function only parses thermal zones.
+ * Cooling devices and sensor devices nodes are supposed to be parsed
+ * by their respective drivers.
+ *
+ * Return: 0 on success, proper error code otherwise
+ *
+ */
+int __init of_parse_thermal_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+	struct thermal_zone_device_ops *ops;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return 0;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+		struct thermal_zone_params *tzp;
+
+		tz = thermal_of_build_thermal_zone(child);
+		if (IS_ERR(tz)) {
+			pr_err("failed to build thermal zone %ld\n",
+			       PTR_ERR(tz));
+			return 0;
+		}
+
+		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal ops\n");
+			return 0;
+		}
+		memcpy(ops, &of_thermal_ops, sizeof(*ops));
+
+		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal zone params\n");
+			return 0;
+		}
+		/* No hwmon because there might be hwmon drivers registering */
+		tzp->no_hwmon = true;
+
+		zone = thermal_zone_device_register(child->name, tz->ntrips,
+						    0, tz,
+						    ops, tzp,
+						    tz->passive_delay,
+						    tz->polling_delay);
+		if (IS_ERR(zone))
+			pr_err("Failed to build %s zone %ld\n", child->name,
+			       PTR_ERR(zone));
+	}
+	return 0;
+}
+
+/**
+ * of_thermal_destroy_zones - remove all zones parsed and allocated resources
+ *
+ * Finds all zones parsed and added to the thermal framework and remove them
+ * from the system, together with their resources.
+ *
+ */
+void __exit of_thermal_destroy_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+
+		zone = thermal_zone_get_zone_by_name(child->name);
+		if (IS_ERR(zone))
+			continue;
+
+		thermal_zone_device_unregister(zone);
+		kfree(zone->tzp);
+		kfree(zone->ops);
+		tz = zone->devdata;
+		kfree(tz->tbps);
+		kfree(tz->trips);
+		kfree(tz);
+	}
+}
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 8a94300..a733241 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
  */
 struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int trips, int mask, void *devdata,
-	const struct thermal_zone_device_ops *ops,
+	struct thermal_zone_device_ops *ops,
 	const struct thermal_zone_params *tzp,
 	int passive_delay, int polling_delay)
 {
@@ -1751,8 +1751,14 @@ static int __init thermal_init(void)
 	if (result)
 		goto unregister_class;
 
+	result = of_parse_thermal_zones();
+	if (result)
+		goto exit_netlink;
+
 	return 0;
 
+exit_netlink:
+	genetlink_exit();
 unregister_governors:
 	thermal_unregister_governors();
 unregister_class:
@@ -1768,6 +1774,7 @@ error:
 
 static void __exit thermal_exit(void)
 {
+	of_thermal_destroy_zones();
 	genetlink_exit();
 	class_unregister(&thermal_class);
 	thermal_unregister_governors();
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 7cf2f66..3db339f 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
 static inline void thermal_gov_user_space_unregister(void) {}
 #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
 
+/* device tree support */
+#ifdef CONFIG_THERMAL_OF
+int of_parse_thermal_zones(void);
+void of_thermal_destroy_zones(void);
+#else
+static inline int of_parse_thermal_zones(void) { return 0; }
+static inline void of_thermal_destroy_zones(void) { }
+#endif
+
 #endif /* __THERMAL_CORE_H__ */
diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h
new file mode 100644
index 0000000..6dd6ccd
--- /dev/null
+++ b/include/dt-bindings/thermal/thermal.h
@@ -0,0 +1,27 @@
+/*
+ * This header provides constants for most thermal bindings.
+ *
+ * Copyright (C) 2013 Texas Instruments
+ *	Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * GPLv2 only
+ */
+
+#ifndef _DT_BINDINGS_THERMAL_THERMAL_H
+#define _DT_BINDINGS_THERMAL_THERMAL_H
+
+/*
+ * Here are the thermal trip types. This must
+ * match with enum thermal_trip_type at
+ * include/linux/thermal.h
+ */
+#define THERMAL_TRIP_ACTIVE		0
+#define THERMAL_TRIP_PASSIVE		1
+#define THERMAL_TRIP_HOT		2
+#define THERMAL_TRIP_CRITICAL		3
+
+/* On cooling devices upper and lower limits */
+#define THERMAL_NO_LIMIT		(-1UL)
+
+#endif
+
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index b268d3c..b780c5b 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -143,6 +143,7 @@ struct thermal_cooling_device {
 	int id;
 	char type[THERMAL_NAME_LENGTH];
 	struct device device;
+	struct device_node *np;
 	void *devdata;
 	const struct thermal_cooling_device_ops *ops;
 	bool updated; /* true if the cooling device does not need update */
@@ -172,7 +173,7 @@ struct thermal_zone_device {
 	int emul_temperature;
 	int passive;
 	unsigned int forced_passive;
-	const struct thermal_zone_device_ops *ops;
+	struct thermal_zone_device_ops *ops;
 	const struct thermal_zone_params *tzp;
 	struct thermal_governor *governor;
 	struct list_head thermal_instances;
@@ -242,8 +243,31 @@ struct thermal_genl_event {
 };
 
 /* Function declarations */
+#ifdef CONFIG_THERMAL_OF
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *));
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz);
+#else
+static inline struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	return NULL;
+}
+
+static inline
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz)
+{
+}
+
+#endif
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
-		void *, const struct thermal_zone_device_ops *,
+		void *, struct thermal_zone_device_ops *,
 		const struct thermal_zone_params *, int, int);
 void thermal_zone_device_unregister(struct thermal_zone_device *);
 
-- 
1.8.2.1.342.gfa7285d

Re: [PATCHv2 02/16] drivers: thermal: introduce device tree parser

[Guenter Roeck]

On Wed, Sep 18, 2013 at 12:03:09PM -0400, Eduardo Valentin wrote:
> This patch introduces a device tree bindings for
> describing the hardware thermal behavior and limits.
> Also a parser to read and interpret the data and feed
> it in the thermal framework is presented.
> 
> This patch introduces a thermal data parser for device
> tree. The parsed data is used to build thermal zones
> and thermal binding parameters. The output data
> can then be used to deploy thermal policies.
> 
> This patch adds also documentation regarding this
> API and how to define tree nodes to use
> this infrastructure.
> 
> Note that, in order to be able to have control
> on the sensor registration on the DT thermal zone,
> it was required to allow changing the thermal zone
> .get_temp callback. For this reason, this patch
> also removes the 'const' modifier from the .ops
> field of thermal zone devices.
> 
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: linux-pm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
> ---
>  .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
>  drivers/thermal/Kconfig                            |  13 +
>  drivers/thermal/Makefile                           |   1 +
>  drivers/thermal/of-thermal.c                       | 753 +++++++++++++++++++++
>  drivers/thermal/thermal_core.c                     |   9 +-
>  drivers/thermal/thermal_core.h                     |   9 +
>  include/dt-bindings/thermal/thermal.h              |  27 +
>  include/linux/thermal.h                            |  28 +-
>  8 files changed, 1335 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
>  create mode 100644 drivers/thermal/of-thermal.c
>  create mode 100644 include/dt-bindings/thermal/thermal.h
> ---
> 
> Hi all,
> 
> As per Guenter's request, I changed this code to fail silently while
> registering sensor drivers.
> 
> Cheers,
> 
> Eduardo
> 
> diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
> new file mode 100644
> index 0000000..6664533
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/thermal.txt
> @@ -0,0 +1,498 @@
> +* Thermal Framework Device Tree descriptor
> +
> +Generic binding to provide a way of defining hardware thermal
> +structure using device tree. A thermal structure includes thermal
> +zones and their components, such as trip points, polling intervals,
> +sensors and cooling devices binding descriptors.
> +
> +The target of device tree thermal descriptors is to describe only
> +the hardware thermal aspects, not how the system must control or which
> +algorithm or policy must be taken in place.
> +
> +There are five types of nodes involved to describe thermal bindings:
> +- sensors: used to describe the device source of temperature sensing;
> +- cooling devices: used to describe devices source of power dissipation control;
> +- trip points: used to describe points in temperature domain defined to
> +make the system aware of hardware limits;
> +- cooling attachments: used to describe links between trip points and
> +cooling devices;
> +- thermal zones: used to describe thermal data within the hardware;
> +
> +It follows a description of each type of these device tree nodes.
> +
> +* Sensor devices
> +
> +Sensor devices are nodes providing temperature sensing capabilities on thermal
> +zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
> +providing temperature data to thermal zones. Temperature sensor devices may
> +control one or more internal sensors.
> +
> +Required property:
> +- #sensor-cells:	Used to provide sensor device specific information
> +			while referring to it. Must be at least 1, in order
> +			to identify uniquely the sensor instances within
> +			the IC. See thermal zone binding for more details
> +			on how consumers refer to sensor devices.
> +
> +* Cooling device nodes
> +
> +Cooling devices are nodes providing control on power dissipation. There
> +are essentially two ways to provide control on power dissipation. First
> +is by means of regulating device performance, which is known as passive
> +cooling. Second is by means of activating devices in order to remove
> +the dissipated heat, which is known as active cooling, e.g. regulating
> +fan speeds. In both cases, cooling devices shall have a way to determine
> +the level of cooling.
> +
> +Required property:
> +- cooling-min-level:	A unsigned integer indicating the smallest
> +			cooling level accepted. Typically 0.
> +- cooling-max-level:	An unsigned integer indicating the largest
> +			cooling level accepted.
> +- #cooling-cells:	Used to provide cooling device specific information
> +			while referring to it. Must be at least 2, in order
> +			to specify minimum and maximum cooling level used
> +			in the reference. See Cooling device attachments section
> +			below for more details on how consumers refer to
> +			cooling devices.
> +
> +* Trip points
> +
> +The trip node is a node to describe a point in the temperature domain
> +in which the system takes an action. This node describes just the point,
> +not the action.
> +
> +Required properties:
> +- temperature:		the trip temperature level, in milliCelsius.
> +- hysteresis:		a (low) hysteresis value on 'temperature'. This is a
> +			relative value, in milliCelsius.
> +- type:			the trip type. Here is the type mapping:
> +	THERMAL_TRIP_ACTIVE	0:	A trip point to enable active cooling
> +	THERMAL_TRIP_PASSIVE	1:	A trip point to enable passive cooling
> +	THERMAL_TRIP_HOT	2:	A trip point to notify emergency
> +	THERMAL_TRIP_CRITICAL	3:	Hardware not reliable.
> +
> +Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
> +
> +* Cooling device attachments
> +
> +The cooling device attachments node is a node to describe how cooling devices
> +get assigned to trip points of the zone. The cooling devices are expected
> +to be loaded in the target system.
> +
> +Required properties:
> +- cooling-device:	A phandle of a cooling device with its parameters,
> +			referring to which cooling device is used in this
> +			binding. The required parameters are: the minimum
> +			cooling level and the maximum cooling level used
> +			in this attach.
> +- trip:			A phandle of a trip point node within the same thermal
> +			zone.
> +
> +Optional property:
> +- contribution:		The cooling contribution to the thermal zone of the
> +			referred cooling device at the referred trip point.
> +			The contribution is a value from 0 to 100. The sum
> +			of all cooling contributions within a thermal zone
> +			must never exceed 100.
> +
> +Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
> +limit parameters means:
> +(i)   - minimum level allowed for minimum cooling level used in the reference.
> +(ii)  - maximum level allowed for maximum cooling level used in the reference.
> +Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
> +
> +* Thermal zones
> +
> +The thermal-zone node is the node containing all the required info
> +for describing a thermal zone, including its cdev bindings. The thermal_zone
> +node must contain, apart from its own properties, one node containing
> +trip nodes and one node containing all the zone cooling attachments.
> +
> +Required properties:
> +- passive-delay:	The maximum number of milliseconds to wait between polls
> +			when performing passive cooling.
> +- polling-delay:	The maximum number of milliseconds to wait between polls
> +			when checking this thermal zone.
> +- sensors:		A list of sensor phandles and their parameters. The
> +			required parameter is the sensor id, in order to
> +			identify internal sensors when the sensor IC features
> +			several sensing units.
> +- trips:		A sub-node containing several trip point nodes required
> +			to describe the thermal zone.
> +- cooling-attachments	A sub-node containing several cooling device attaches
> +			nodes, used to describe the relation between trips
> +			and cooling devices.
> +
> +Optional property:
> +- coefficients:		An array of integers (one signed cell) containing
> +			coefficients to compose a linear relation between
> +			the sensors described in the sensors property.
> +			Coefficients defaults to 1, in case this property
> +			is not specified. A simple linear polynomial is used:
> +			Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
> +
> +			The coefficients are ordered and they match with sensors
> +			by means of sensor ID. Additional coefficients are
> +			interpreted as constant offsets.
> +
> +Note: The delay properties are bound to the maximum dT/dt (temperature
> +derivative over time) in two situations for a thermal zone:
> +(i)  - when active cooling is activated (passive-delay); and
> +(ii) - when the zone just needs to be monitored (polling-delay).
> +The maximum dT/dt is highly bound to hardware power consumption and dissipation
> +capability.
> +
> +* Examples
> +
> +Below are several examples on how to use thermal data descriptors
> +using device tree bindings:
> +
> +(a) - CPU thermal zone
> +
> +The CPU thermal zone example below describes how to setup one thermal zone
> +using one single sensor as temperature source and many cooling devices and
> +power dissipation control sources.
> +
> +#include <dt-bindings/thermal/thermal.h>
> +
> +cpus {
> +	cpu0: cpu@0 {
> +		...
> +		cooling-min-level = <0>;
> +		cooling-max-level = <3>;
> +		#cooling-cells = <2>; /* min followed by max */
> +	};
> +	...
> +};
> +
> +&i2c1 {
> +	...
> +	fan0: fan@0x48 {
> +		...
> +		cooling-min-level = <0>;
> +		cooling-max-level = <9>;
> +		#cooling-cells = <2>; /* min followed by max */
> +	};
> +};
> +
> +bandgap0: bandgap@0x0000ED00 {
> +	...
> +	#sensor-cells = <1>;
> +};
> +
> +cpu-thermal: cpu-thermal {
> +	passive-delay = <250>; /* milliseconds */
> +	polling-delay = <1000>; /* milliseconds */
> +
> +		/* sensor       ID */
> +        sensors = <&bandgap0     0>;
> +
> +        trips {
> +                cpu-alert0: cpu-alert {
> +                        temperature = <90000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_ACTIVE>;
> +                };
> +                cpu-alert1: cpu-alert {
> +                        temperature = <100000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_PASSIVE>;
> +                };
> +                cpu-crit: cpu-crit {
> +                        temperature = <125000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_CRITICAL>;
> +                };
> +        };
> +
> +	cooling-attachments {
> +		attach0 {
> +			trip = <&cpu-alert0>;
> +			cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
> +		};
> +		attach1 {
> +			trip = <&cpu-alert1>;
> +			cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
> +		};
> +		attach2 {
> +			trip = <&cpu-alert1>;
> +			cooling-device =
> +				<&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
> +		};
> +	};
> +};
> +
> +In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
> +the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
> +via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
> +zone 'cpu-thermal' using its cooling levels from its minimum to 4, when it
> +reaches trip point 'cpu-alert0' at 90C, as an example of active cooling. The
> +same cooling device is used at 'cpu-alert1', but from 5 to its maximum level.
> +The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
> +passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
> +which is a trip point at 100C.
> +
> +(b) - IC with several internal sensors
> +
> +The example below describes how to deploy several thermal zones based off a
> +single sensor IC, assuming it has several internal sensors. This is a common
> +case on SoC designs with several internal IPs that may need different thermal
> +requirements, and thus may have their own sensor to monitor or detect internal
> +hotspots in their silicon.
> +
> +#include <dt-bindings/thermal/thermal.h>
> +
> +bandgap0: bandgap@0x0000ED00 {
> +	...
> +	#sensor-cells = <1>;
> +};
> +
> +cpu-thermal: cpu-thermal {
> +	passive-delay = <250>; /* milliseconds */
> +	polling-delay = <1000>; /* milliseconds */
> +
> +		/* sensor       ID */
> +        sensors = <&bandgap0     0>;
> +
> +        trips {
> +		/* each zone within the SoC may have its own trips */
> +                cpu-alert: cpu-alert {
> +                        temperature = <100000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_PASSIVE>;
> +                };
> +                cpu-crit: cpu-crit {
> +                        temperature = <125000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_CRITICAL>;
> +                };
> +        };
> +
> +	cooling-attachments {
> +		/* each zone within the SoC may have its own cooling */
> +		...
> +	};
> +};
> +
> +gpu-thermal: gpu-thermal {
> +	passive-delay = <120>; /* milliseconds */
> +	polling-delay = <1000>; /* milliseconds */
> +
> +		/* sensor       ID */
> +        sensors = <&bandgap0     1>;
> +
> +        trips {
> +		/* each zone within the SoC may have its own trips */
> +                gpu-alert: gpu-alert {
> +                        temperature = <90000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_PASSIVE>;
> +                };
> +                gpu-crit: gpu-crit {
> +                        temperature = <105000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_CRITICAL>;
> +                };
> +        };
> +
> +	cooling-attachments {
> +		/* each zone within the SoC may have its own cooling */
> +		...
> +	};
> +};
> +
> +dsp-thermal: dsp-thermal {
> +	passive-delay = <50>; /* milliseconds */
> +	polling-delay = <1000>; /* milliseconds */
> +
> +		/* sensor       ID */
> +        sensors = <&bandgap0     2>;
> +
> +        trips {
> +		/* each zone within the SoC may have its own trips */
> +                dsp-alert: gpu-alert {
> +                        temperature = <90000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_PASSIVE>;
> +                };
> +                dsp-crit: gpu-crit {
> +                        temperature = <135000>; /* milliCelsius */
> +                        hysteresis = <2000>; /* milliCelsius */
> +                        type = <THERMAL_TRIP_CRITICAL>;
> +                };
> +        };
> +
> +	cooling-attachments {
> +		/* each zone within the SoC may have its own cooling */
> +		...
> +	};
> +};
> +
> +In the example above there is one bandgap IC which has the capability to
> +monitor three sensors. The hardware has been designed so that sensors are
> +placed on different places in the DIE to monitor different temperature
> +hotspots: one for CPU thermal zone, one for GPU thermal zone and the
> +other to monitor a DSP thermal zone.
> +
> +Thus, there is a need to assign each sensor provided by the bandgap IC
> +to different thermal zones. This is achieved by means of using the
> +#sensor-cells property and using the first parameter as sensor ID.
> +In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
> +bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
> +is used to monitor DSP thermal zone. Each zone may be uncorrelated,
> +having its own dT/dt requirements, trips and cooling attachments.
> +
> +
> +(c) - Several sensors within one single thermal zone
> +
> +The example below illustrates how to use more than one sensor within
> +one thermal zone.
> +
> +#include <dt-bindings/thermal/thermal.h>
> +
> +&i2c1 {
> +	...
> +	adc: sensor@0x49 {
> +		...
> +		#sensor-cells = <1>;
> +	};
> +};
> +
> +bandgap0: bandgap@0x0000ED00 {
> +	...
> +	#sensor-cells = <1>;
> +};
> +
> +cpu-thermal: cpu-thermal {
> +	passive-delay = <250>; /* milliseconds */
> +	polling-delay = <1000>; /* milliseconds */
> +
> +		/* sensor       ID */
> +        sensors = <&bandgap0	0>,
> +		  <&adc		0>;
> +
> +		/* hotspot = 100 * bandgap - 120 * adc + 484 */
> +	coefficients = 		<100	-120	484>;
> +
> +        trips {
> +		...
> +        };
> +
> +	cooling-attachments {
> +		...
> +	};
> +};
> +
> +In some cases, there is a need to use more than one sensor to extrapolate
> +a thermal hotspot in the silicon. The above example illustrate this situation.
> +For instance, it may be the case that a sensor external to CPU IP may be place
> +close to CPU hotspot and together with internal CPU sensor, it is used
> +to determine the hotspot. The hyppotetical extrapolation rule would be:
> +		hotspot = 100 * bandgap - 120 * adc + 484
> +
> +The same idea can be used to add fixed offset:
> +	passive-delay = <1000>; /* milliseconds */
> +	polling-delay = <2500>; /* milliseconds */
> +		hotspot = 1 * adc + 6000
> +
> +In the above equation, the hotspot is always 6C higher than what is read
> +from the sensor ADC. The binding would be then:
> +		/* sensor       ID */
> +        sensors =  <&adc	0>;
> +
> +		/* hotspot = 1 * adc + 6000 */
> +	coefficients = 		<1	6000>;
> +
> +(d) - Board thermal
> +
> +The board thermal example below illustrates how to setup one thermal zone
> +with many sensors and many cooling devices.
> +
> +#include <dt-bindings/thermal/thermal.h>
> +
> +&i2c1 {
> +	...
> +	adc-dummy: sensor@0x50 {
> +		...
> +		#sensor-cells = <1>; /* sensor internal ID */
> +	};
> +};
> +
> +batt-thermal {
> +	passive-delay = <500>; /* milliseconds */
> +	polling-delay = <2500>; /* milliseconds */
> +
> +	/* sensor       ID */
> +	sensors = <&adc-dummy     4>;
> +
> +	trips {
> +		...
> +	};
> +
> +	cooling-attachments {
> +		...
> +	};
> +};
> +
> +board-thermal: board-thermal {
> +	passive-delay = <1000>; /* milliseconds */
> +	polling-delay = <2500>; /* milliseconds */
> +
> +		/* sensor       ID */
> +	sensors = <&adc-dummy     0>,
> +		  <&adc-dummy     1>,
> +		  <&adc-dymmy     2>;
> +			/*
> +			 * An array of coefficients describing the sensor
> +			 * linear relation. E.g.:
> +			 * z = c1*x1 + c2*x2 + c3*x3
> +			 */
> +	coefficients =		<1200	-345	890>;
> +
> +	trips {
> +		/* Trips are based on resulting linear equation */
> +		cpu-trip: cpu-trip {
> +			temperature = <60000>; /* milliCelsius */
> +			hysteresis = <2000>; /* milliCelsius */
> +			type = <THERMAL_TRIP_PASSIVE>;
> +		};
> +		gpu-trip: gpu-trip {
> +			temperature = <55000>; /* milliCelsius */
> +			hysteresis = <2000>; /* milliCelsius */
> +			type = <THERMAL_TRIP_PASSIVE>;
> +		}
> +		lcd-trip: lcp-trip {
> +			temperature = <53000>; /* milliCelsius */
> +			hysteresis = <2000>; /* milliCelsius */
> +			type = <THERMAL_TRIP_PASSIVE>;
> +		};
> +		crit-trip: crit-trip {
> +			temperature = <68000>; /* milliCelsius */
> +			hysteresis = <2000>; /* milliCelsius */
> +			type = <THERMAL_TRIP_CRITICAL>;
> +		};
> +	};
> +
> +	cooling-attachments {
> +		attach0 {
> +			trip = <&cpu-trip>;
> +			cooling-device = <&cpu0 0 2>;
> +			contribution = <55>;
> +		};
> +		attach1 {
> +			trip = <&gpu-trip>;
> +			cooling-device = <&gpu0 0 2>;
> +			contribution = <20>;
> +		};
> +		attach2 {
> +			trip = <&lcd-trip>;
> +			cooling-device = <&lcd0 5 10>;
> +			contribution = <15>;
> +		};
> +	};
> +};
> +
> +The above example is a mix of previous examples, a sensor IP with several internal
> +sensors used to monitor different zones, one of them is composed by several sensors and
> +with different cooling devices.
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index dbfc390..dd81eb8 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -29,6 +29,19 @@ config THERMAL_HWMON
>  	  Say 'Y' here if you want all thermal sensors to
>  	  have hwmon sysfs interface too.
>  
> +config THERMAL_OF
> +	bool
> +	prompt "APIs to parse thermal data out of device tree"
> +	depends on OF
> +	default y
> +	help
> +	  This options provides helpers to add the support to
> +	  read and parse thermal data definitions out of the
> +	  device tree blob.
> +
> +	  Say 'Y' here if you need to build thermal infrastructure
> +	  based on device tree.
> +
>  choice
>  	prompt "Default Thermal governor"
>  	default THERMAL_DEFAULT_GOV_STEP_WISE
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 584b363..4b03956 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
>  
>  # interface to/from other layers providing sensors
>  thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
> +thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
>  
>  # governors
>  thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
> new file mode 100644
> index 0000000..857d40c
> --- /dev/null
> +++ b/drivers/thermal/of-thermal.c
> @@ -0,0 +1,753 @@
> +/*
> + *  of-thermal.c - Generic Thermal Management device tree support.
> + *
> + *  Copyright (C) 2013 Texas Instruments
> + *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
> + *
> + *
> + *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + *
> + *  This program is free software; you can redistribute it and/or modify
> + *  it under the terms of the GNU General Public License as published by
> + *  the Free Software Foundation; version 2 of the License.
> + *
> + *  This program is distributed in the hope that it will be useful, but
> + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + *  General Public License for more details.
> + *
> + *  You should have received a copy of the GNU General Public License along
> + *  with this program; if not, write to the Free Software Foundation, Inc.,
> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + */
> +#include <linux/thermal.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/err.h>
> +#include <linux/export.h>
> +#include <linux/string.h>
> +
> +/***   Private data structures to represent thermal device tree data ***/
> +
> +/**
> + * struct __thermal_trip - representation of a point in temperature domain
> + * @np: pointer to struct device_node that this trip point was created from
> + * @temperature: temperature value in miliCelsius
> + * @hysteresis: relative hysteresis in miliCelsius
> + * @type: trip point type
> + */
> +
> +struct __thermal_trip {
> +	struct device_node *np;
> +	unsigned long int temperature;
> +	unsigned long int hysteresis;
> +	enum thermal_trip_type type;
> +};
> +
> +/**
> + * struct __thermal_bind_param - a match between trip and cooling device
> + * @cooling_device: a pointer to identify the referred cooling device
> + * @trip_id: the trip point index
> + * @usage: the percentage (from 0 to 100) of cooling contribution
> + * @min: minimum cooling level used at this trip point
> + * @max: maximum cooling level used at this trip point
> + */
> +
> +struct __thermal_bind_params {
> +	struct device_node *cooling_device;
> +	unsigned int trip_id;
> +	unsigned int usage;
> +	unsigned long min;
> +	unsigned long max;
> +};
> +
> +/**
> + * struct __thermal_zone - internal representation of a thermal zone
> + * @mode: current thermal zone device mode (enabled/disabled)
> + * @passive_delay: polling interval while passive cooling is activated
> + * @polling_delay: zone polling interval
> + * @ntrips: number of trip points
> + * @trips: an array of trip points (0..ntrips - 1)
> + * @num_tbps: number of thermal bind params
> + * @tbps: an array of thermal bind params (0..num_tbps - 1)
> + * @sensor_data: sensor private data used while reading temperature and trend
> + * @get_temp: sensor callback to read temperature
> + * @get_trend: sensor callback to read temperature trend
> + */
> +
> +struct __thermal_zone {
> +	enum thermal_device_mode mode;
> +	int passive_delay;
> +	int polling_delay;
> +
> +	/* trip data */
> +	int ntrips;
> +	struct __thermal_trip *trips;
> +
> +	/* cooling binding data */
> +	int num_tbps;
> +	struct __thermal_bind_params *tbps;
> +
> +	/* sensor interface */
> +	void *sensor_data;
> +	int (*get_temp)(void *, long *);
> +	int (*get_trend)(void *, long *);
> +};
> +
> +/***   DT thermal zone device callbacks   ***/
> +
> +static int of_thermal_get_temp(struct thermal_zone_device *tz,
> +			       unsigned long *temp)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (!data->get_temp)
> +		return -EINVAL;
> +
> +	return data->get_temp(data->sensor_data, temp);
> +}
> +
> +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
> +				enum thermal_trend *trend)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +	long dev_trend;
> +	int r;
> +
> +	if (!data->get_trend)
> +		return -EINVAL;
> +
> +	r = data->get_trend(data->sensor_data, &dev_trend);
> +	if (r)
> +		return r;
> +
> +	if (dev_trend > 0)
> +		*trend = THERMAL_TREND_RAISING;
> +	else if (dev_trend < 0)
> +		*trend = THERMAL_TREND_DROPPING;
> +	else
> +		*trend = THERMAL_TREND_STABLE;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_bind(struct thermal_zone_device *thermal,
> +			   struct thermal_cooling_device *cdev)
> +{
> +	struct __thermal_zone *data = thermal->devdata;
> +	int i;
> +
> +	if (!data || IS_ERR(data))
> +		return -ENODEV;
> +
> +	/* find where to bind */
> +	for (i = 0; i < data->num_tbps; i++) {
> +		struct __thermal_bind_params *tbp = data->tbps + i;
> +
> +		if (tbp->cooling_device == cdev->np) {
> +			int ret;
> +
> +			ret = thermal_zone_bind_cooling_device(thermal,
> +						tbp->trip_id, cdev,
> +						tbp->min,
> +						tbp->max);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int of_thermal_unbind(struct thermal_zone_device *thermal,
> +			     struct thermal_cooling_device *cdev)
> +{
> +	struct __thermal_zone *data = thermal->devdata;
> +	int i;
> +
> +	if (!data || IS_ERR(data))
> +		return -ENODEV;
> +
> +	/* find where to unbind */
> +	for (i = 0; i < data->num_tbps; i++) {
> +		struct __thermal_bind_params *tbp = data->tbps + i;
> +
> +		if (tbp->cooling_device == cdev->np) {
> +			int ret;
> +
> +			ret = thermal_zone_unbind_cooling_device(thermal,
> +						tbp->trip_id, cdev);
> +			if (ret)
> +				return ret;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int of_thermal_get_mode(struct thermal_zone_device *tz,
> +			       enum thermal_device_mode *mode)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	*mode = data->mode;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_set_mode(struct thermal_zone_device *tz,
> +			       enum thermal_device_mode mode)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	mutex_lock(&tz->lock);
> +
> +	if (mode == THERMAL_DEVICE_ENABLED)
> +		tz->polling_delay = data->polling_delay;
> +	else
> +		tz->polling_delay = 0;
> +
> +	mutex_unlock(&tz->lock);
> +
> +	data->mode = mode;
> +	thermal_zone_device_update(tz);
> +
> +	return 0;
> +}
> +
> +static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
> +				    enum thermal_trip_type *type)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (trip >= data->ntrips || trip < 0)
> +		return -EDOM;
> +
> +	*type = data->trips[trip].type;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
> +				    unsigned long *temp)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (trip >= data->ntrips || trip < 0)
> +		return -EDOM;
> +
> +	*temp = data->trips[trip].temperature;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
> +				    unsigned long temp)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (trip >= data->ntrips || trip < 0)
> +		return -EDOM;
> +
> +	/* thermal fw should take care of data->mask & (1 << trip) */
> +	data->trips[trip].temperature = temp;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
> +				    unsigned long *hyst)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (trip >= data->ntrips || trip < 0)
> +		return -EDOM;
> +
> +	*hyst = data->trips[trip].hysteresis;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
> +				    unsigned long hyst)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +
> +	if (trip >= data->ntrips || trip < 0)
> +		return -EDOM;
> +
> +	/* thermal fw should take care of data->mask & (1 << trip) */
> +	data->trips[trip].hysteresis = hyst;
> +
> +	return 0;
> +}
> +
> +static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
> +				    unsigned long *temp)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +	int i;
> +
> +	for (i = 0; i < data->ntrips; i++)
> +		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
> +			*temp = data->trips[i].temperature;
> +			return 0;
> +		}
> +
> +	return -EINVAL;
> +}
> +
> +static struct thermal_zone_device_ops of_thermal_ops = {
> +	.get_mode = of_thermal_get_mode,
> +	.set_mode = of_thermal_set_mode,
> +
> +	.get_trip_type = of_thermal_get_trip_type,
> +	.get_trip_temp = of_thermal_get_trip_temp,
> +	.set_trip_temp = of_thermal_set_trip_temp,
> +	.get_trip_hyst = of_thermal_get_trip_hyst,
> +	.set_trip_hyst = of_thermal_set_trip_hyst,
> +	.get_crit_temp = of_thermal_get_crit_temp,
> +
> +	.bind = of_thermal_bind,
> +	.unbind = of_thermal_unbind,
> +};
> +
> +/***   sensor API   ***/
> +
> +static struct thermal_zone_device *
> +thermal_zone_of_add_sensor(struct device_node *zone,
> +			   struct device_node *sensor, void *data,
> +			   int (*get_temp)(void *, long *),
> +			   int (*get_trend)(void *, long *))
> +{
> +	struct thermal_zone_device *tzd;
> +	struct __thermal_zone *tz;
> +
> +	tzd = thermal_zone_get_zone_by_name(zone->name);
> +	if (IS_ERR(tzd))
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	tz = tzd->devdata;
> +
> +	mutex_lock(&tzd->lock);
> +	tz->get_temp = get_temp;
> +	tz->get_trend = get_trend;
> +	tz->sensor_data = data;
> +
> +	tzd->ops->get_temp = of_thermal_get_temp;
> +	tzd->ops->get_trend = of_thermal_get_trend;
> +	mutex_unlock(&tzd->lock);
> +
> +	return tzd;
> +}
> +
> +/**
> + * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
> + * @dev: a valid struct device pointer of a sensor device. Must contain
> + *       a valid .of_node, for the sensor node.
> + * @sensor_id: a sensor identifier, in case the sensor IP has more
> + *             than one sensors
> + * @data: a private pointer (owned by the caller) that will be passed
> + *        back, when a temperature reading is needed.
> + * @get_temp: a pointer to a function that reads the sensor temperature.
> + * @get_trend: a pointer to a function that reads the sensor temperature trend.
> + *
> + * This function will search the list of thermal zones described in device
> + * tree and look for the zone that refer to the sensor device pointed by
> + * @dev->of_node as temperature providers. For the zone pointing to the
> + * sensor node, the sensor will be added to the DT thermal zone device.
> + *
> + * The thermal zone temperature is provided by the @get_temp function
> + * pointer. When called, it will have the private pointer @data back.
> + *
> + * The thermal zone temperature trend is provided by the @get_trend function
> + * pointer. When called, it will have the private pointer @data back.
> + *
> + * TODO:
> + * 01 - This function must enqueue the new sensor instead of using
> + * it as the only source of temperature values.
> + *
> + * 02 - There must be a way to match the sensor with all thermal zones
> + * that refer to it.
> + *
> + * Return: On success returns a valid struct thermal_zone_device,
> + * otherwise, it returns a corresponding ERR_PTR(). Caller must
> + * check the return value with help of IS_ERR() helper.
> + */
> +struct thermal_zone_device *
> +thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
> +				void *data, int (*get_temp)(void *, long *),
> +				int (*get_trend)(void *, long *))
> +{
> +	struct device_node *np, *child, *sensor_np;
> +
> +	np = of_find_node_by_name(NULL, "thermal-zones");
> +	if (!np)
> +		return ERR_PTR(-ENODEV);
> +
> +	if (!dev || !dev->of_node)
> +		return ERR_PTR(-EINVAL);
> +
> +	sensor_np = dev->of_node;
> +
> +	for_each_child_of_node(np, child) {
> +		struct of_phandle_args sensor_specs;
> +		int ret;
> +
> +		/* For now, thermal framework supports only 1 sensor per zone */
> +		ret = of_parse_phandle_with_args(child, "sensors",
> +						 "#sensor-cells",
> +						 0, &sensor_specs);
> +		if (ret)
> +			continue;
> +
> +		if (sensor_specs.args_count < 1)
> +			continue;
> +
> +		if (sensor_specs.np == sensor_np &&
> +		    sensor_specs.args[0] == sensor_id) {
> +			of_node_put(np);
> +			return thermal_zone_of_add_sensor(child, sensor_np,
> +							  data,
> +							  get_temp,
> +							  get_trend);
> +		}
> +	}
> +	of_node_put(np);
> +
> +	return ERR_PTR(-ENODEV);
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
> +
> +/**
> + * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
> + * @dev: a valid struct device pointer of a sensor device. Must contain
> + *       a valid .of_node, for the sensor node.
> + * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
> + *
> + * This function removes the sensor callbacks and private data from the
> + * thermal zone device registered with thermal_zone_of_sensor_register()
> + * API. It will also silent the zone by remove the .get_temp() and .get_trend()
> + * thermal zone device callbacks.
> + *
> + * TODO: When the support to several sensors per zone is added, this
> + * function must search the sensor list based on @dev parameter.
> + *
> + */
> +void thermal_zone_of_sensor_unregister(struct device *dev,
> +				       struct thermal_zone_device *tzd)
> +{
> +	struct __thermal_zone *tz = tzd->devdata;
> +

You might want to check for a NULL thermal zone device before dereferencing it.

Guenter

> +	/* no __thermal_zone, nothing to be done */
> +	if (!tz)
> +		return;
> +
> +	mutex_lock(&tzd->lock);
> +	tzd->ops->get_temp = NULL;
> +	tzd->ops->get_trend = NULL;
> +
> +	tz->get_temp = NULL;
> +	tz->get_trend = NULL;
> +	tz->sensor_data = NULL;
> +	mutex_unlock(&tzd->lock);
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
> +
> +/***   functions parsing device tree nodes   ***/
> +
> +/**
> + * thermal_of_populate_bind_params - parse and fill cooling attachment data
> + * @np: DT node containing a cooling-attachment node
> + * @__tbp: data structure to be filled with cooling attachment info
> + * @trips: array of thermal zone trip points
> + * @ntrips: number of trip points inside trips.
> + *
> + * This function parses a cooling-attachment type of node represented by
> + * @np parameter and fills the read data into @__tbp data structure.
> + * It needs the already parsed array of trip points of the thermal zone
> + * in consideration.
> + *
> + * Return: 0 on success, proper error code otherwise
> + */
> +static int thermal_of_populate_bind_params(struct device_node *np,
> +					   struct __thermal_bind_params *__tbp,
> +					   struct __thermal_trip *trips,
> +					   int ntrips)
> +{
> +	struct of_phandle_args cooling_spec;
> +	struct device_node *trip;
> +	int ret, i;
> +	u32 prop;
> +
> +	/* Default weight. Usage is optional */
> +	__tbp->usage = 0;
> +	ret = of_property_read_u32(np, "usage", &prop);
> +	if (ret == 0)
> +		__tbp->usage = prop;
> +
> +	trip = of_parse_phandle(np, "trip", 0);
> +	if (!trip) {
> +		pr_err("missing trip property\n");
> +		return -ENODEV;
> +	}
> +
> +	/* match using device_node */
> +	for (i = 0; i < ntrips; i++)
> +		if (trip == trips[i].np) {
> +			__tbp->trip_id = i;
> +			break;
> +		}
> +
> +	if (i == ntrips) {
> +		ret = -ENODEV;
> +		goto end;
> +	}
> +
> +	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
> +					 0, &cooling_spec);
> +	if (ret < 0) {
> +		pr_err("missing cooling_device property\n");
> +		goto end;
> +	}
> +	__tbp->cooling_device = cooling_spec.np;
> +	if (cooling_spec.args_count >= 2) { /* at least min and max */
> +		__tbp->min = cooling_spec.args[0];
> +		__tbp->max = cooling_spec.args[1];
> +	} else {
> +		pr_err("wrong reference to cooling device, missing limits\n");
> +	}
> +
> +end:
> +	of_node_put(trip);
> +
> +	return ret;
> +}
> +
> +/**
> + * thermal_of_populate_trip - parse and fill one trip point data
> + * @np: DT node containing a trip point node
> + * @trip: trip point data structure to be filled up
> + *
> + * This function parses a trip point type of node represented by
> + * @np parameter and fills the read data into @trip data structure.
> + *
> + * Return: 0 on success, proper error code otherwise
> + */
> +static int thermal_of_populate_trip(struct device_node *np,
> +				    struct __thermal_trip *trip)
> +{
> +	int prop;
> +	int ret;
> +
> +	ret = of_property_read_u32(np, "temperature", &prop);
> +	if (ret < 0) {
> +		pr_err("missing temperature property\n");
> +		return ret;
> +	}
> +	trip->temperature = prop;
> +
> +	ret = of_property_read_u32(np, "hysteresis", &prop);
> +	if (ret < 0) {
> +		pr_err("missing hysteresis property\n");
> +		return ret;
> +	}
> +	trip->hysteresis = prop;
> +
> +	ret = of_property_read_u32(np, "type", &prop);
> +	if (ret < 0) {
> +		pr_err("missing type property\n");
> +		return ret;
> +	}
> +	trip->type = prop;
> +
> +	/* Required for cooling attachment matching */
> +	trip->np = np;
> +
> +	return 0;
> +}
> +
> +/**
> + * thermal_of_build_thermal_zone - parse and fill one thermal zone data
> + * @np: DT node containing a thermal zone node
> + *
> + * This function parses a thermal zone type of node represented by
> + * @np parameter and fills the read data into a __thermal_zone data structure
> + * and return this pointer.
> + *
> + * Return: On success returns a valid struct __thermal_zone,
> + * otherwise, it returns a corresponding ERR_PTR(). Caller must
> + * check the return value with help of IS_ERR() helper.
> + */
> +static struct __thermal_zone *
> +thermal_of_build_thermal_zone(struct device_node *np)
> +{
> +	struct device_node *child, *gchild;
> +	struct __thermal_zone *tz;
> +	int ret, i;
> +	u32 prop;
> +
> +	if (!np) {
> +		pr_err("no thermal zone np\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
> +	if (!tz) {
> +		pr_err("not enough memory for thermal of zone\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	ret = of_property_read_u32(np, "passive-delay", &prop);
> +	if (ret < 0) {
> +		pr_err("missing passive_delay property\n");
> +		return ERR_PTR(ret);
> +	}
> +	tz->passive_delay = prop;
> +
> +	ret = of_property_read_u32(np, "polling-delay", &prop);
> +	if (ret < 0) {
> +		pr_err("missing polling_delay property\n");
> +		return ERR_PTR(ret);
> +	}
> +	tz->polling_delay = prop;
> +
> +	/* trips */
> +	child = of_get_child_by_name(np, "trips");
> +
> +	/* No trips provided */
> +	if (!child)
> +		goto finish;
> +
> +	tz->ntrips = of_get_child_count(child);
> +	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
> +	if (!tz->trips)
> +		return ERR_PTR(-ENOMEM);
> +	i = 0;
> +	for_each_child_of_node(child, gchild)
> +		thermal_of_populate_trip(gchild, &tz->trips[i++]);
> +
> +	of_node_put(child);
> +
> +	/* cooling-attachments */
> +	child = of_get_child_by_name(np, "cooling-attachments");
> +
> +	/* cooling-attachments provided */
> +	if (!child)
> +		goto finish;
> +
> +	tz->num_tbps = of_get_child_count(child);
> +	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
> +	if (!tz->tbps)
> +		return ERR_PTR(-ENOMEM);
> +	i = 0;
> +	for_each_child_of_node(child, gchild)
> +		thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
> +						tz->trips, tz->ntrips);
> +
> +finish:
> +	tz->mode = THERMAL_DEVICE_DISABLED;
> +
> +	return tz;
> +}
> +
> +/**
> + * of_parse_thermal_zones - parse device tree thermal data
> + *
> + * Initialization function that can be called by machine initialization
> + * code to parse thermal data and populate the thermal framework
> + * with hardware thermal zones info. This function only parses thermal zones.
> + * Cooling devices and sensor devices nodes are supposed to be parsed
> + * by their respective drivers.
> + *
> + * Return: 0 on success, proper error code otherwise
> + *
> + */
> +int __init of_parse_thermal_zones(void)
> +{
> +	struct device_node *np, *child;
> +	struct __thermal_zone *tz;
> +	struct thermal_zone_device_ops *ops;
> +
> +	np = of_find_node_by_name(NULL, "thermal-zones");
> +	if (!np) {
> +		pr_err("unable to find thermal zones\n");
> +		return 0;
> +	}
> +
> +	for_each_child_of_node(np, child) {
> +		struct thermal_zone_device *zone;
> +		struct thermal_zone_params *tzp;
> +
> +		tz = thermal_of_build_thermal_zone(child);
> +		if (IS_ERR(tz)) {
> +			pr_err("failed to build thermal zone %ld\n",
> +			       PTR_ERR(tz));
> +			return 0;
> +		}
> +
> +		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
> +		if (!ops) {
> +			pr_err("no memory available for thermal ops\n");
> +			return 0;
> +		}
> +		memcpy(ops, &of_thermal_ops, sizeof(*ops));
> +
> +		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
> +		if (!ops) {
> +			pr_err("no memory available for thermal zone params\n");
> +			return 0;
> +		}
> +		/* No hwmon because there might be hwmon drivers registering */
> +		tzp->no_hwmon = true;
> +
> +		zone = thermal_zone_device_register(child->name, tz->ntrips,
> +						    0, tz,
> +						    ops, tzp,
> +						    tz->passive_delay,
> +						    tz->polling_delay);
> +		if (IS_ERR(zone))
> +			pr_err("Failed to build %s zone %ld\n", child->name,
> +			       PTR_ERR(zone));
> +	}
> +	return 0;
> +}
> +
> +/**
> + * of_thermal_destroy_zones - remove all zones parsed and allocated resources
> + *
> + * Finds all zones parsed and added to the thermal framework and remove them
> + * from the system, together with their resources.
> + *
> + */
> +void __exit of_thermal_destroy_zones(void)
> +{
> +	struct device_node *np, *child;
> +	struct __thermal_zone *tz;
> +
> +	np = of_find_node_by_name(NULL, "thermal-zones");
> +	if (!np) {
> +		pr_err("unable to find thermal zones\n");
> +		return;
> +	}
> +
> +	for_each_child_of_node(np, child) {
> +		struct thermal_zone_device *zone;
> +
> +		zone = thermal_zone_get_zone_by_name(child->name);
> +		if (IS_ERR(zone))
> +			continue;
> +
> +		thermal_zone_device_unregister(zone);
> +		kfree(zone->tzp);
> +		kfree(zone->ops);
> +		tz = zone->devdata;
> +		kfree(tz->tbps);
> +		kfree(tz->trips);
> +		kfree(tz);
> +	}
> +}
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 8a94300..a733241 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
>   */
>  struct thermal_zone_device *thermal_zone_device_register(const char *type,
>  	int trips, int mask, void *devdata,
> -	const struct thermal_zone_device_ops *ops,
> +	struct thermal_zone_device_ops *ops,
>  	const struct thermal_zone_params *tzp,
>  	int passive_delay, int polling_delay)
>  {
> @@ -1751,8 +1751,14 @@ static int __init thermal_init(void)
>  	if (result)
>  		goto unregister_class;
>  
> +	result = of_parse_thermal_zones();
> +	if (result)
> +		goto exit_netlink;
> +
>  	return 0;
>  
> +exit_netlink:
> +	genetlink_exit();
>  unregister_governors:
>  	thermal_unregister_governors();
>  unregister_class:
> @@ -1768,6 +1774,7 @@ error:
>  
>  static void __exit thermal_exit(void)
>  {
> +	of_thermal_destroy_zones();
>  	genetlink_exit();
>  	class_unregister(&thermal_class);
>  	thermal_unregister_governors();
> diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
> index 7cf2f66..3db339f 100644
> --- a/drivers/thermal/thermal_core.h
> +++ b/drivers/thermal/thermal_core.h
> @@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
>  static inline void thermal_gov_user_space_unregister(void) {}
>  #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
>  
> +/* device tree support */
> +#ifdef CONFIG_THERMAL_OF
> +int of_parse_thermal_zones(void);
> +void of_thermal_destroy_zones(void);
> +#else
> +static inline int of_parse_thermal_zones(void) { return 0; }
> +static inline void of_thermal_destroy_zones(void) { }
> +#endif
> +
>  #endif /* __THERMAL_CORE_H__ */
> diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h
> new file mode 100644
> index 0000000..6dd6ccd
> --- /dev/null
> +++ b/include/dt-bindings/thermal/thermal.h
> @@ -0,0 +1,27 @@
> +/*
> + * This header provides constants for most thermal bindings.
> + *
> + * Copyright (C) 2013 Texas Instruments
> + *	Eduardo Valentin <eduardo.valentin@ti.com>
> + *
> + * GPLv2 only
> + */
> +
> +#ifndef _DT_BINDINGS_THERMAL_THERMAL_H
> +#define _DT_BINDINGS_THERMAL_THERMAL_H
> +
> +/*
> + * Here are the thermal trip types. This must
> + * match with enum thermal_trip_type at
> + * include/linux/thermal.h
> + */
> +#define THERMAL_TRIP_ACTIVE		0
> +#define THERMAL_TRIP_PASSIVE		1
> +#define THERMAL_TRIP_HOT		2
> +#define THERMAL_TRIP_CRITICAL		3
> +
> +/* On cooling devices upper and lower limits */
> +#define THERMAL_NO_LIMIT		(-1UL)
> +
> +#endif
> +
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index b268d3c..b780c5b 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -143,6 +143,7 @@ struct thermal_cooling_device {
>  	int id;
>  	char type[THERMAL_NAME_LENGTH];
>  	struct device device;
> +	struct device_node *np;
>  	void *devdata;
>  	const struct thermal_cooling_device_ops *ops;
>  	bool updated; /* true if the cooling device does not need update */
> @@ -172,7 +173,7 @@ struct thermal_zone_device {
>  	int emul_temperature;
>  	int passive;
>  	unsigned int forced_passive;
> -	const struct thermal_zone_device_ops *ops;
> +	struct thermal_zone_device_ops *ops;
>  	const struct thermal_zone_params *tzp;
>  	struct thermal_governor *governor;
>  	struct list_head thermal_instances;
> @@ -242,8 +243,31 @@ struct thermal_genl_event {
>  };
>  
>  /* Function declarations */
> +#ifdef CONFIG_THERMAL_OF
> +struct thermal_zone_device *
> +thermal_zone_of_sensor_register(struct device *dev, int id,
> +				void *data, int (*get_temp)(void *, long *),
> +				int (*get_trend)(void *, long *));
> +void thermal_zone_of_sensor_unregister(struct device *dev,
> +				       struct thermal_zone_device *tz);
> +#else
> +static inline struct thermal_zone_device *
> +thermal_zone_of_sensor_register(struct device *dev, int id,
> +				void *data, int (*get_temp)(void *, long *),
> +				int (*get_trend)(void *, long *))
> +{
> +	return NULL;
> +}
> +
> +static inline
> +void thermal_zone_of_sensor_unregister(struct device *dev,
> +				       struct thermal_zone_device *tz)
> +{
> +}
> +
> +#endif
>  struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
> -		void *, const struct thermal_zone_device_ops *,
> +		void *, struct thermal_zone_device_ops *,
>  		const struct thermal_zone_params *, int, int);
>  void thermal_zone_device_unregister(struct thermal_zone_device *);
>  
> -- 
> 1.8.2.1.342.gfa7285d
> 
> 

Re: [PATCHv2 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 51668 bytes --]

On 18-09-2013 13:08, Guenter Roeck wrote:
> On Wed, Sep 18, 2013 at 12:03:09PM -0400, Eduardo Valentin wrote:
>> This patch introduces a device tree bindings for
>> describing the hardware thermal behavior and limits.
>> Also a parser to read and interpret the data and feed
>> it in the thermal framework is presented.
>>
>> This patch introduces a thermal data parser for device
>> tree. The parsed data is used to build thermal zones
>> and thermal binding parameters. The output data
>> can then be used to deploy thermal policies.
>>
>> This patch adds also documentation regarding this
>> API and how to define tree nodes to use
>> this infrastructure.
>>
>> Note that, in order to be able to have control
>> on the sensor registration on the DT thermal zone,
>> it was required to allow changing the thermal zone
>> .get_temp callback. For this reason, this patch
>> also removes the 'const' modifier from the .ops
>> field of thermal zone devices.
>>
>> Cc: Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>> Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>> ---
>>  .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
>>  drivers/thermal/Kconfig                            |  13 +
>>  drivers/thermal/Makefile                           |   1 +
>>  drivers/thermal/of-thermal.c                       | 753 +++++++++++++++++++++
>>  drivers/thermal/thermal_core.c                     |   9 +-
>>  drivers/thermal/thermal_core.h                     |   9 +
>>  include/dt-bindings/thermal/thermal.h              |  27 +
>>  include/linux/thermal.h                            |  28 +-
>>  8 files changed, 1335 insertions(+), 3 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
>>  create mode 100644 drivers/thermal/of-thermal.c
>>  create mode 100644 include/dt-bindings/thermal/thermal.h
>> ---
>>
>> Hi all,
>>
>> As per Guenter's request, I changed this code to fail silently while
>> registering sensor drivers.
>>
>> Cheers,
>>
>> Eduardo
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
>> new file mode 100644
>> index 0000000..6664533
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/thermal/thermal.txt
>> @@ -0,0 +1,498 @@
>> +* Thermal Framework Device Tree descriptor
>> +
>> +Generic binding to provide a way of defining hardware thermal
>> +structure using device tree. A thermal structure includes thermal
>> +zones and their components, such as trip points, polling intervals,
>> +sensors and cooling devices binding descriptors.
>> +
>> +The target of device tree thermal descriptors is to describe only
>> +the hardware thermal aspects, not how the system must control or which
>> +algorithm or policy must be taken in place.
>> +
>> +There are five types of nodes involved to describe thermal bindings:
>> +- sensors: used to describe the device source of temperature sensing;
>> +- cooling devices: used to describe devices source of power dissipation control;
>> +- trip points: used to describe points in temperature domain defined to
>> +make the system aware of hardware limits;
>> +- cooling attachments: used to describe links between trip points and
>> +cooling devices;
>> +- thermal zones: used to describe thermal data within the hardware;
>> +
>> +It follows a description of each type of these device tree nodes.
>> +
>> +* Sensor devices
>> +
>> +Sensor devices are nodes providing temperature sensing capabilities on thermal
>> +zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
>> +providing temperature data to thermal zones. Temperature sensor devices may
>> +control one or more internal sensors.
>> +
>> +Required property:
>> +- #sensor-cells:	Used to provide sensor device specific information
>> +			while referring to it. Must be at least 1, in order
>> +			to identify uniquely the sensor instances within
>> +			the IC. See thermal zone binding for more details
>> +			on how consumers refer to sensor devices.
>> +
>> +* Cooling device nodes
>> +
>> +Cooling devices are nodes providing control on power dissipation. There
>> +are essentially two ways to provide control on power dissipation. First
>> +is by means of regulating device performance, which is known as passive
>> +cooling. Second is by means of activating devices in order to remove
>> +the dissipated heat, which is known as active cooling, e.g. regulating
>> +fan speeds. In both cases, cooling devices shall have a way to determine
>> +the level of cooling.
>> +
>> +Required property:
>> +- cooling-min-level:	A unsigned integer indicating the smallest
>> +			cooling level accepted. Typically 0.
>> +- cooling-max-level:	An unsigned integer indicating the largest
>> +			cooling level accepted.
>> +- #cooling-cells:	Used to provide cooling device specific information
>> +			while referring to it. Must be at least 2, in order
>> +			to specify minimum and maximum cooling level used
>> +			in the reference. See Cooling device attachments section
>> +			below for more details on how consumers refer to
>> +			cooling devices.
>> +
>> +* Trip points
>> +
>> +The trip node is a node to describe a point in the temperature domain
>> +in which the system takes an action. This node describes just the point,
>> +not the action.
>> +
>> +Required properties:
>> +- temperature:		the trip temperature level, in milliCelsius.
>> +- hysteresis:		a (low) hysteresis value on 'temperature'. This is a
>> +			relative value, in milliCelsius.
>> +- type:			the trip type. Here is the type mapping:
>> +	THERMAL_TRIP_ACTIVE	0:	A trip point to enable active cooling
>> +	THERMAL_TRIP_PASSIVE	1:	A trip point to enable passive cooling
>> +	THERMAL_TRIP_HOT	2:	A trip point to notify emergency
>> +	THERMAL_TRIP_CRITICAL	3:	Hardware not reliable.
>> +
>> +Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
>> +
>> +* Cooling device attachments
>> +
>> +The cooling device attachments node is a node to describe how cooling devices
>> +get assigned to trip points of the zone. The cooling devices are expected
>> +to be loaded in the target system.
>> +
>> +Required properties:
>> +- cooling-device:	A phandle of a cooling device with its parameters,
>> +			referring to which cooling device is used in this
>> +			binding. The required parameters are: the minimum
>> +			cooling level and the maximum cooling level used
>> +			in this attach.
>> +- trip:			A phandle of a trip point node within the same thermal
>> +			zone.
>> +
>> +Optional property:
>> +- contribution:		The cooling contribution to the thermal zone of the
>> +			referred cooling device at the referred trip point.
>> +			The contribution is a value from 0 to 100. The sum
>> +			of all cooling contributions within a thermal zone
>> +			must never exceed 100.
>> +
>> +Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
>> +limit parameters means:
>> +(i)   - minimum level allowed for minimum cooling level used in the reference.
>> +(ii)  - maximum level allowed for maximum cooling level used in the reference.
>> +Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
>> +
>> +* Thermal zones
>> +
>> +The thermal-zone node is the node containing all the required info
>> +for describing a thermal zone, including its cdev bindings. The thermal_zone
>> +node must contain, apart from its own properties, one node containing
>> +trip nodes and one node containing all the zone cooling attachments.
>> +
>> +Required properties:
>> +- passive-delay:	The maximum number of milliseconds to wait between polls
>> +			when performing passive cooling.
>> +- polling-delay:	The maximum number of milliseconds to wait between polls
>> +			when checking this thermal zone.
>> +- sensors:		A list of sensor phandles and their parameters. The
>> +			required parameter is the sensor id, in order to
>> +			identify internal sensors when the sensor IC features
>> +			several sensing units.
>> +- trips:		A sub-node containing several trip point nodes required
>> +			to describe the thermal zone.
>> +- cooling-attachments	A sub-node containing several cooling device attaches
>> +			nodes, used to describe the relation between trips
>> +			and cooling devices.
>> +
>> +Optional property:
>> +- coefficients:		An array of integers (one signed cell) containing
>> +			coefficients to compose a linear relation between
>> +			the sensors described in the sensors property.
>> +			Coefficients defaults to 1, in case this property
>> +			is not specified. A simple linear polynomial is used:
>> +			Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
>> +
>> +			The coefficients are ordered and they match with sensors
>> +			by means of sensor ID. Additional coefficients are
>> +			interpreted as constant offsets.
>> +
>> +Note: The delay properties are bound to the maximum dT/dt (temperature
>> +derivative over time) in two situations for a thermal zone:
>> +(i)  - when active cooling is activated (passive-delay); and
>> +(ii) - when the zone just needs to be monitored (polling-delay).
>> +The maximum dT/dt is highly bound to hardware power consumption and dissipation
>> +capability.
>> +
>> +* Examples
>> +
>> +Below are several examples on how to use thermal data descriptors
>> +using device tree bindings:
>> +
>> +(a) - CPU thermal zone
>> +
>> +The CPU thermal zone example below describes how to setup one thermal zone
>> +using one single sensor as temperature source and many cooling devices and
>> +power dissipation control sources.
>> +
>> +#include <dt-bindings/thermal/thermal.h>
>> +
>> +cpus {
>> +	cpu0: cpu@0 {
>> +		...
>> +		cooling-min-level = <0>;
>> +		cooling-max-level = <3>;
>> +		#cooling-cells = <2>; /* min followed by max */
>> +	};
>> +	...
>> +};
>> +
>> +&i2c1 {
>> +	...
>> +	fan0: fan@0x48 {
>> +		...
>> +		cooling-min-level = <0>;
>> +		cooling-max-level = <9>;
>> +		#cooling-cells = <2>; /* min followed by max */
>> +	};
>> +};
>> +
>> +bandgap0: bandgap@0x0000ED00 {
>> +	...
>> +	#sensor-cells = <1>;
>> +};
>> +
>> +cpu-thermal: cpu-thermal {
>> +	passive-delay = <250>; /* milliseconds */
>> +	polling-delay = <1000>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +        sensors = <&bandgap0     0>;
>> +
>> +        trips {
>> +                cpu-alert0: cpu-alert {
>> +                        temperature = <90000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_ACTIVE>;
>> +                };
>> +                cpu-alert1: cpu-alert {
>> +                        temperature = <100000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_PASSIVE>;
>> +                };
>> +                cpu-crit: cpu-crit {
>> +                        temperature = <125000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_CRITICAL>;
>> +                };
>> +        };
>> +
>> +	cooling-attachments {
>> +		attach0 {
>> +			trip = <&cpu-alert0>;
>> +			cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
>> +		};
>> +		attach1 {
>> +			trip = <&cpu-alert1>;
>> +			cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
>> +		};
>> +		attach2 {
>> +			trip = <&cpu-alert1>;
>> +			cooling-device =
>> +				<&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
>> +		};
>> +	};
>> +};
>> +
>> +In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
>> +the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
>> +via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
>> +zone 'cpu-thermal' using its cooling levels from its minimum to 4, when it
>> +reaches trip point 'cpu-alert0' at 90C, as an example of active cooling. The
>> +same cooling device is used at 'cpu-alert1', but from 5 to its maximum level.
>> +The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
>> +passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
>> +which is a trip point at 100C.
>> +
>> +(b) - IC with several internal sensors
>> +
>> +The example below describes how to deploy several thermal zones based off a
>> +single sensor IC, assuming it has several internal sensors. This is a common
>> +case on SoC designs with several internal IPs that may need different thermal
>> +requirements, and thus may have their own sensor to monitor or detect internal
>> +hotspots in their silicon.
>> +
>> +#include <dt-bindings/thermal/thermal.h>
>> +
>> +bandgap0: bandgap@0x0000ED00 {
>> +	...
>> +	#sensor-cells = <1>;
>> +};
>> +
>> +cpu-thermal: cpu-thermal {
>> +	passive-delay = <250>; /* milliseconds */
>> +	polling-delay = <1000>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +        sensors = <&bandgap0     0>;
>> +
>> +        trips {
>> +		/* each zone within the SoC may have its own trips */
>> +                cpu-alert: cpu-alert {
>> +                        temperature = <100000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_PASSIVE>;
>> +                };
>> +                cpu-crit: cpu-crit {
>> +                        temperature = <125000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_CRITICAL>;
>> +                };
>> +        };
>> +
>> +	cooling-attachments {
>> +		/* each zone within the SoC may have its own cooling */
>> +		...
>> +	};
>> +};
>> +
>> +gpu-thermal: gpu-thermal {
>> +	passive-delay = <120>; /* milliseconds */
>> +	polling-delay = <1000>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +        sensors = <&bandgap0     1>;
>> +
>> +        trips {
>> +		/* each zone within the SoC may have its own trips */
>> +                gpu-alert: gpu-alert {
>> +                        temperature = <90000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_PASSIVE>;
>> +                };
>> +                gpu-crit: gpu-crit {
>> +                        temperature = <105000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_CRITICAL>;
>> +                };
>> +        };
>> +
>> +	cooling-attachments {
>> +		/* each zone within the SoC may have its own cooling */
>> +		...
>> +	};
>> +};
>> +
>> +dsp-thermal: dsp-thermal {
>> +	passive-delay = <50>; /* milliseconds */
>> +	polling-delay = <1000>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +        sensors = <&bandgap0     2>;
>> +
>> +        trips {
>> +		/* each zone within the SoC may have its own trips */
>> +                dsp-alert: gpu-alert {
>> +                        temperature = <90000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_PASSIVE>;
>> +                };
>> +                dsp-crit: gpu-crit {
>> +                        temperature = <135000>; /* milliCelsius */
>> +                        hysteresis = <2000>; /* milliCelsius */
>> +                        type = <THERMAL_TRIP_CRITICAL>;
>> +                };
>> +        };
>> +
>> +	cooling-attachments {
>> +		/* each zone within the SoC may have its own cooling */
>> +		...
>> +	};
>> +};
>> +
>> +In the example above there is one bandgap IC which has the capability to
>> +monitor three sensors. The hardware has been designed so that sensors are
>> +placed on different places in the DIE to monitor different temperature
>> +hotspots: one for CPU thermal zone, one for GPU thermal zone and the
>> +other to monitor a DSP thermal zone.
>> +
>> +Thus, there is a need to assign each sensor provided by the bandgap IC
>> +to different thermal zones. This is achieved by means of using the
>> +#sensor-cells property and using the first parameter as sensor ID.
>> +In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
>> +bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
>> +is used to monitor DSP thermal zone. Each zone may be uncorrelated,
>> +having its own dT/dt requirements, trips and cooling attachments.
>> +
>> +
>> +(c) - Several sensors within one single thermal zone
>> +
>> +The example below illustrates how to use more than one sensor within
>> +one thermal zone.
>> +
>> +#include <dt-bindings/thermal/thermal.h>
>> +
>> +&i2c1 {
>> +	...
>> +	adc: sensor@0x49 {
>> +		...
>> +		#sensor-cells = <1>;
>> +	};
>> +};
>> +
>> +bandgap0: bandgap@0x0000ED00 {
>> +	...
>> +	#sensor-cells = <1>;
>> +};
>> +
>> +cpu-thermal: cpu-thermal {
>> +	passive-delay = <250>; /* milliseconds */
>> +	polling-delay = <1000>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +        sensors = <&bandgap0	0>,
>> +		  <&adc		0>;
>> +
>> +		/* hotspot = 100 * bandgap - 120 * adc + 484 */
>> +	coefficients = 		<100	-120	484>;
>> +
>> +        trips {
>> +		...
>> +        };
>> +
>> +	cooling-attachments {
>> +		...
>> +	};
>> +};
>> +
>> +In some cases, there is a need to use more than one sensor to extrapolate
>> +a thermal hotspot in the silicon. The above example illustrate this situation.
>> +For instance, it may be the case that a sensor external to CPU IP may be place
>> +close to CPU hotspot and together with internal CPU sensor, it is used
>> +to determine the hotspot. The hyppotetical extrapolation rule would be:
>> +		hotspot = 100 * bandgap - 120 * adc + 484
>> +
>> +The same idea can be used to add fixed offset:
>> +	passive-delay = <1000>; /* milliseconds */
>> +	polling-delay = <2500>; /* milliseconds */
>> +		hotspot = 1 * adc + 6000
>> +
>> +In the above equation, the hotspot is always 6C higher than what is read
>> +from the sensor ADC. The binding would be then:
>> +		/* sensor       ID */
>> +        sensors =  <&adc	0>;
>> +
>> +		/* hotspot = 1 * adc + 6000 */
>> +	coefficients = 		<1	6000>;
>> +
>> +(d) - Board thermal
>> +
>> +The board thermal example below illustrates how to setup one thermal zone
>> +with many sensors and many cooling devices.
>> +
>> +#include <dt-bindings/thermal/thermal.h>
>> +
>> +&i2c1 {
>> +	...
>> +	adc-dummy: sensor@0x50 {
>> +		...
>> +		#sensor-cells = <1>; /* sensor internal ID */
>> +	};
>> +};
>> +
>> +batt-thermal {
>> +	passive-delay = <500>; /* milliseconds */
>> +	polling-delay = <2500>; /* milliseconds */
>> +
>> +	/* sensor       ID */
>> +	sensors = <&adc-dummy     4>;
>> +
>> +	trips {
>> +		...
>> +	};
>> +
>> +	cooling-attachments {
>> +		...
>> +	};
>> +};
>> +
>> +board-thermal: board-thermal {
>> +	passive-delay = <1000>; /* milliseconds */
>> +	polling-delay = <2500>; /* milliseconds */
>> +
>> +		/* sensor       ID */
>> +	sensors = <&adc-dummy     0>,
>> +		  <&adc-dummy     1>,
>> +		  <&adc-dymmy     2>;
>> +			/*
>> +			 * An array of coefficients describing the sensor
>> +			 * linear relation. E.g.:
>> +			 * z = c1*x1 + c2*x2 + c3*x3
>> +			 */
>> +	coefficients =		<1200	-345	890>;
>> +
>> +	trips {
>> +		/* Trips are based on resulting linear equation */
>> +		cpu-trip: cpu-trip {
>> +			temperature = <60000>; /* milliCelsius */
>> +			hysteresis = <2000>; /* milliCelsius */
>> +			type = <THERMAL_TRIP_PASSIVE>;
>> +		};
>> +		gpu-trip: gpu-trip {
>> +			temperature = <55000>; /* milliCelsius */
>> +			hysteresis = <2000>; /* milliCelsius */
>> +			type = <THERMAL_TRIP_PASSIVE>;
>> +		}
>> +		lcd-trip: lcp-trip {
>> +			temperature = <53000>; /* milliCelsius */
>> +			hysteresis = <2000>; /* milliCelsius */
>> +			type = <THERMAL_TRIP_PASSIVE>;
>> +		};
>> +		crit-trip: crit-trip {
>> +			temperature = <68000>; /* milliCelsius */
>> +			hysteresis = <2000>; /* milliCelsius */
>> +			type = <THERMAL_TRIP_CRITICAL>;
>> +		};
>> +	};
>> +
>> +	cooling-attachments {
>> +		attach0 {
>> +			trip = <&cpu-trip>;
>> +			cooling-device = <&cpu0 0 2>;
>> +			contribution = <55>;
>> +		};
>> +		attach1 {
>> +			trip = <&gpu-trip>;
>> +			cooling-device = <&gpu0 0 2>;
>> +			contribution = <20>;
>> +		};
>> +		attach2 {
>> +			trip = <&lcd-trip>;
>> +			cooling-device = <&lcd0 5 10>;
>> +			contribution = <15>;
>> +		};
>> +	};
>> +};
>> +
>> +The above example is a mix of previous examples, a sensor IP with several internal
>> +sensors used to monitor different zones, one of them is composed by several sensors and
>> +with different cooling devices.
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index dbfc390..dd81eb8 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -29,6 +29,19 @@ config THERMAL_HWMON
>>  	  Say 'Y' here if you want all thermal sensors to
>>  	  have hwmon sysfs interface too.
>>  
>> +config THERMAL_OF
>> +	bool
>> +	prompt "APIs to parse thermal data out of device tree"
>> +	depends on OF
>> +	default y
>> +	help
>> +	  This options provides helpers to add the support to
>> +	  read and parse thermal data definitions out of the
>> +	  device tree blob.
>> +
>> +	  Say 'Y' here if you need to build thermal infrastructure
>> +	  based on device tree.
>> +
>>  choice
>>  	prompt "Default Thermal governor"
>>  	default THERMAL_DEFAULT_GOV_STEP_WISE
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index 584b363..4b03956 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
>>  
>>  # interface to/from other layers providing sensors
>>  thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
>> +thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
>>  
>>  # governors
>>  thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
>> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
>> new file mode 100644
>> index 0000000..857d40c
>> --- /dev/null
>> +++ b/drivers/thermal/of-thermal.c
>> @@ -0,0 +1,753 @@
>> +/*
>> + *  of-thermal.c - Generic Thermal Management device tree support.
>> + *
>> + *  Copyright (C) 2013 Texas Instruments
>> + *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>> + *
>> + *
>> + *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + *
>> + *  This program is free software; you can redistribute it and/or modify
>> + *  it under the terms of the GNU General Public License as published by
>> + *  the Free Software Foundation; version 2 of the License.
>> + *
>> + *  This program is distributed in the hope that it will be useful, but
>> + *  WITHOUT ANY WARRANTY; without even the implied warranty of
>> + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + *  General Public License for more details.
>> + *
>> + *  You should have received a copy of the GNU General Public License along
>> + *  with this program; if not, write to the Free Software Foundation, Inc.,
>> + *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
>> + *
>> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> + */
>> +#include <linux/thermal.h>
>> +#include <linux/slab.h>
>> +#include <linux/types.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/err.h>
>> +#include <linux/export.h>
>> +#include <linux/string.h>
>> +
>> +/***   Private data structures to represent thermal device tree data ***/
>> +
>> +/**
>> + * struct __thermal_trip - representation of a point in temperature domain
>> + * @np: pointer to struct device_node that this trip point was created from
>> + * @temperature: temperature value in miliCelsius
>> + * @hysteresis: relative hysteresis in miliCelsius
>> + * @type: trip point type
>> + */
>> +
>> +struct __thermal_trip {
>> +	struct device_node *np;
>> +	unsigned long int temperature;
>> +	unsigned long int hysteresis;
>> +	enum thermal_trip_type type;
>> +};
>> +
>> +/**
>> + * struct __thermal_bind_param - a match between trip and cooling device
>> + * @cooling_device: a pointer to identify the referred cooling device
>> + * @trip_id: the trip point index
>> + * @usage: the percentage (from 0 to 100) of cooling contribution
>> + * @min: minimum cooling level used at this trip point
>> + * @max: maximum cooling level used at this trip point
>> + */
>> +
>> +struct __thermal_bind_params {
>> +	struct device_node *cooling_device;
>> +	unsigned int trip_id;
>> +	unsigned int usage;
>> +	unsigned long min;
>> +	unsigned long max;
>> +};
>> +
>> +/**
>> + * struct __thermal_zone - internal representation of a thermal zone
>> + * @mode: current thermal zone device mode (enabled/disabled)
>> + * @passive_delay: polling interval while passive cooling is activated
>> + * @polling_delay: zone polling interval
>> + * @ntrips: number of trip points
>> + * @trips: an array of trip points (0..ntrips - 1)
>> + * @num_tbps: number of thermal bind params
>> + * @tbps: an array of thermal bind params (0..num_tbps - 1)
>> + * @sensor_data: sensor private data used while reading temperature and trend
>> + * @get_temp: sensor callback to read temperature
>> + * @get_trend: sensor callback to read temperature trend
>> + */
>> +
>> +struct __thermal_zone {
>> +	enum thermal_device_mode mode;
>> +	int passive_delay;
>> +	int polling_delay;
>> +
>> +	/* trip data */
>> +	int ntrips;
>> +	struct __thermal_trip *trips;
>> +
>> +	/* cooling binding data */
>> +	int num_tbps;
>> +	struct __thermal_bind_params *tbps;
>> +
>> +	/* sensor interface */
>> +	void *sensor_data;
>> +	int (*get_temp)(void *, long *);
>> +	int (*get_trend)(void *, long *);
>> +};
>> +
>> +/***   DT thermal zone device callbacks   ***/
>> +
>> +static int of_thermal_get_temp(struct thermal_zone_device *tz,
>> +			       unsigned long *temp)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (!data->get_temp)
>> +		return -EINVAL;
>> +
>> +	return data->get_temp(data->sensor_data, temp);
>> +}
>> +
>> +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
>> +				enum thermal_trend *trend)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +	long dev_trend;
>> +	int r;
>> +
>> +	if (!data->get_trend)
>> +		return -EINVAL;
>> +
>> +	r = data->get_trend(data->sensor_data, &dev_trend);
>> +	if (r)
>> +		return r;
>> +
>> +	if (dev_trend > 0)
>> +		*trend = THERMAL_TREND_RAISING;
>> +	else if (dev_trend < 0)
>> +		*trend = THERMAL_TREND_DROPPING;
>> +	else
>> +		*trend = THERMAL_TREND_STABLE;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_bind(struct thermal_zone_device *thermal,
>> +			   struct thermal_cooling_device *cdev)
>> +{
>> +	struct __thermal_zone *data = thermal->devdata;
>> +	int i;
>> +
>> +	if (!data || IS_ERR(data))
>> +		return -ENODEV;
>> +
>> +	/* find where to bind */
>> +	for (i = 0; i < data->num_tbps; i++) {
>> +		struct __thermal_bind_params *tbp = data->tbps + i;
>> +
>> +		if (tbp->cooling_device == cdev->np) {
>> +			int ret;
>> +
>> +			ret = thermal_zone_bind_cooling_device(thermal,
>> +						tbp->trip_id, cdev,
>> +						tbp->min,
>> +						tbp->max);
>> +			if (ret)
>> +				return ret;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_unbind(struct thermal_zone_device *thermal,
>> +			     struct thermal_cooling_device *cdev)
>> +{
>> +	struct __thermal_zone *data = thermal->devdata;
>> +	int i;
>> +
>> +	if (!data || IS_ERR(data))
>> +		return -ENODEV;
>> +
>> +	/* find where to unbind */
>> +	for (i = 0; i < data->num_tbps; i++) {
>> +		struct __thermal_bind_params *tbp = data->tbps + i;
>> +
>> +		if (tbp->cooling_device == cdev->np) {
>> +			int ret;
>> +
>> +			ret = thermal_zone_unbind_cooling_device(thermal,
>> +						tbp->trip_id, cdev);
>> +			if (ret)
>> +				return ret;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_get_mode(struct thermal_zone_device *tz,
>> +			       enum thermal_device_mode *mode)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	*mode = data->mode;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_set_mode(struct thermal_zone_device *tz,
>> +			       enum thermal_device_mode mode)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	mutex_lock(&tz->lock);
>> +
>> +	if (mode == THERMAL_DEVICE_ENABLED)
>> +		tz->polling_delay = data->polling_delay;
>> +	else
>> +		tz->polling_delay = 0;
>> +
>> +	mutex_unlock(&tz->lock);
>> +
>> +	data->mode = mode;
>> +	thermal_zone_device_update(tz);
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
>> +				    enum thermal_trip_type *type)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (trip >= data->ntrips || trip < 0)
>> +		return -EDOM;
>> +
>> +	*type = data->trips[trip].type;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
>> +				    unsigned long *temp)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (trip >= data->ntrips || trip < 0)
>> +		return -EDOM;
>> +
>> +	*temp = data->trips[trip].temperature;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
>> +				    unsigned long temp)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (trip >= data->ntrips || trip < 0)
>> +		return -EDOM;
>> +
>> +	/* thermal fw should take care of data->mask & (1 << trip) */
>> +	data->trips[trip].temperature = temp;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
>> +				    unsigned long *hyst)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (trip >= data->ntrips || trip < 0)
>> +		return -EDOM;
>> +
>> +	*hyst = data->trips[trip].hysteresis;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
>> +				    unsigned long hyst)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +
>> +	if (trip >= data->ntrips || trip < 0)
>> +		return -EDOM;
>> +
>> +	/* thermal fw should take care of data->mask & (1 << trip) */
>> +	data->trips[trip].hysteresis = hyst;
>> +
>> +	return 0;
>> +}
>> +
>> +static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
>> +				    unsigned long *temp)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +	int i;
>> +
>> +	for (i = 0; i < data->ntrips; i++)
>> +		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
>> +			*temp = data->trips[i].temperature;
>> +			return 0;
>> +		}
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static struct thermal_zone_device_ops of_thermal_ops = {
>> +	.get_mode = of_thermal_get_mode,
>> +	.set_mode = of_thermal_set_mode,
>> +
>> +	.get_trip_type = of_thermal_get_trip_type,
>> +	.get_trip_temp = of_thermal_get_trip_temp,
>> +	.set_trip_temp = of_thermal_set_trip_temp,
>> +	.get_trip_hyst = of_thermal_get_trip_hyst,
>> +	.set_trip_hyst = of_thermal_set_trip_hyst,
>> +	.get_crit_temp = of_thermal_get_crit_temp,
>> +
>> +	.bind = of_thermal_bind,
>> +	.unbind = of_thermal_unbind,
>> +};
>> +
>> +/***   sensor API   ***/
>> +
>> +static struct thermal_zone_device *
>> +thermal_zone_of_add_sensor(struct device_node *zone,
>> +			   struct device_node *sensor, void *data,
>> +			   int (*get_temp)(void *, long *),
>> +			   int (*get_trend)(void *, long *))
>> +{
>> +	struct thermal_zone_device *tzd;
>> +	struct __thermal_zone *tz;
>> +
>> +	tzd = thermal_zone_get_zone_by_name(zone->name);
>> +	if (IS_ERR(tzd))
>> +		return ERR_PTR(-EPROBE_DEFER);
>> +
>> +	tz = tzd->devdata;
>> +
>> +	mutex_lock(&tzd->lock);
>> +	tz->get_temp = get_temp;
>> +	tz->get_trend = get_trend;
>> +	tz->sensor_data = data;
>> +
>> +	tzd->ops->get_temp = of_thermal_get_temp;
>> +	tzd->ops->get_trend = of_thermal_get_trend;
>> +	mutex_unlock(&tzd->lock);
>> +
>> +	return tzd;
>> +}
>> +
>> +/**
>> + * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
>> + * @dev: a valid struct device pointer of a sensor device. Must contain
>> + *       a valid .of_node, for the sensor node.
>> + * @sensor_id: a sensor identifier, in case the sensor IP has more
>> + *             than one sensors
>> + * @data: a private pointer (owned by the caller) that will be passed
>> + *        back, when a temperature reading is needed.
>> + * @get_temp: a pointer to a function that reads the sensor temperature.
>> + * @get_trend: a pointer to a function that reads the sensor temperature trend.
>> + *
>> + * This function will search the list of thermal zones described in device
>> + * tree and look for the zone that refer to the sensor device pointed by
>> + * @dev->of_node as temperature providers. For the zone pointing to the
>> + * sensor node, the sensor will be added to the DT thermal zone device.
>> + *
>> + * The thermal zone temperature is provided by the @get_temp function
>> + * pointer. When called, it will have the private pointer @data back.
>> + *
>> + * The thermal zone temperature trend is provided by the @get_trend function
>> + * pointer. When called, it will have the private pointer @data back.
>> + *
>> + * TODO:
>> + * 01 - This function must enqueue the new sensor instead of using
>> + * it as the only source of temperature values.
>> + *
>> + * 02 - There must be a way to match the sensor with all thermal zones
>> + * that refer to it.
>> + *
>> + * Return: On success returns a valid struct thermal_zone_device,
>> + * otherwise, it returns a corresponding ERR_PTR(). Caller must
>> + * check the return value with help of IS_ERR() helper.
>> + */
>> +struct thermal_zone_device *
>> +thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
>> +				void *data, int (*get_temp)(void *, long *),
>> +				int (*get_trend)(void *, long *))
>> +{
>> +	struct device_node *np, *child, *sensor_np;
>> +
>> +	np = of_find_node_by_name(NULL, "thermal-zones");
>> +	if (!np)
>> +		return ERR_PTR(-ENODEV);
>> +
>> +	if (!dev || !dev->of_node)
>> +		return ERR_PTR(-EINVAL);
>> +
>> +	sensor_np = dev->of_node;
>> +
>> +	for_each_child_of_node(np, child) {
>> +		struct of_phandle_args sensor_specs;
>> +		int ret;
>> +
>> +		/* For now, thermal framework supports only 1 sensor per zone */
>> +		ret = of_parse_phandle_with_args(child, "sensors",
>> +						 "#sensor-cells",
>> +						 0, &sensor_specs);
>> +		if (ret)
>> +			continue;
>> +
>> +		if (sensor_specs.args_count < 1)
>> +			continue;
>> +
>> +		if (sensor_specs.np == sensor_np &&
>> +		    sensor_specs.args[0] == sensor_id) {
>> +			of_node_put(np);
>> +			return thermal_zone_of_add_sensor(child, sensor_np,
>> +							  data,
>> +							  get_temp,
>> +							  get_trend);
>> +		}
>> +	}
>> +	of_node_put(np);
>> +
>> +	return ERR_PTR(-ENODEV);
>> +}
>> +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
>> +
>> +/**
>> + * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
>> + * @dev: a valid struct device pointer of a sensor device. Must contain
>> + *       a valid .of_node, for the sensor node.
>> + * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
>> + *
>> + * This function removes the sensor callbacks and private data from the
>> + * thermal zone device registered with thermal_zone_of_sensor_register()
>> + * API. It will also silent the zone by remove the .get_temp() and .get_trend()
>> + * thermal zone device callbacks.
>> + *
>> + * TODO: When the support to several sensors per zone is added, this
>> + * function must search the sensor list based on @dev parameter.
>> + *
>> + */
>> +void thermal_zone_of_sensor_unregister(struct device *dev,
>> +				       struct thermal_zone_device *tzd)
>> +{
>> +	struct __thermal_zone *tz = tzd->devdata;
>> +
> 
> You might want to check for a NULL thermal zone device before dereferencing it.

Good point Guenter, thanks for your time reviewing this code.

I am resending this patch only with this fix as its v3.

Eduardo

> 
> Guenter
> 
>> +	/* no __thermal_zone, nothing to be done */
>> +	if (!tz)
>> +		return;
>> +
>> +	mutex_lock(&tzd->lock);
>> +	tzd->ops->get_temp = NULL;
>> +	tzd->ops->get_trend = NULL;
>> +
>> +	tz->get_temp = NULL;
>> +	tz->get_trend = NULL;
>> +	tz->sensor_data = NULL;
>> +	mutex_unlock(&tzd->lock);
>> +}
>> +EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
>> +
>> +/***   functions parsing device tree nodes   ***/
>> +
>> +/**
>> + * thermal_of_populate_bind_params - parse and fill cooling attachment data
>> + * @np: DT node containing a cooling-attachment node
>> + * @__tbp: data structure to be filled with cooling attachment info
>> + * @trips: array of thermal zone trip points
>> + * @ntrips: number of trip points inside trips.
>> + *
>> + * This function parses a cooling-attachment type of node represented by
>> + * @np parameter and fills the read data into @__tbp data structure.
>> + * It needs the already parsed array of trip points of the thermal zone
>> + * in consideration.
>> + *
>> + * Return: 0 on success, proper error code otherwise
>> + */
>> +static int thermal_of_populate_bind_params(struct device_node *np,
>> +					   struct __thermal_bind_params *__tbp,
>> +					   struct __thermal_trip *trips,
>> +					   int ntrips)
>> +{
>> +	struct of_phandle_args cooling_spec;
>> +	struct device_node *trip;
>> +	int ret, i;
>> +	u32 prop;
>> +
>> +	/* Default weight. Usage is optional */
>> +	__tbp->usage = 0;
>> +	ret = of_property_read_u32(np, "usage", &prop);
>> +	if (ret == 0)
>> +		__tbp->usage = prop;
>> +
>> +	trip = of_parse_phandle(np, "trip", 0);
>> +	if (!trip) {
>> +		pr_err("missing trip property\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	/* match using device_node */
>> +	for (i = 0; i < ntrips; i++)
>> +		if (trip == trips[i].np) {
>> +			__tbp->trip_id = i;
>> +			break;
>> +		}
>> +
>> +	if (i == ntrips) {
>> +		ret = -ENODEV;
>> +		goto end;
>> +	}
>> +
>> +	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
>> +					 0, &cooling_spec);
>> +	if (ret < 0) {
>> +		pr_err("missing cooling_device property\n");
>> +		goto end;
>> +	}
>> +	__tbp->cooling_device = cooling_spec.np;
>> +	if (cooling_spec.args_count >= 2) { /* at least min and max */
>> +		__tbp->min = cooling_spec.args[0];
>> +		__tbp->max = cooling_spec.args[1];
>> +	} else {
>> +		pr_err("wrong reference to cooling device, missing limits\n");
>> +	}
>> +
>> +end:
>> +	of_node_put(trip);
>> +
>> +	return ret;
>> +}
>> +
>> +/**
>> + * thermal_of_populate_trip - parse and fill one trip point data
>> + * @np: DT node containing a trip point node
>> + * @trip: trip point data structure to be filled up
>> + *
>> + * This function parses a trip point type of node represented by
>> + * @np parameter and fills the read data into @trip data structure.
>> + *
>> + * Return: 0 on success, proper error code otherwise
>> + */
>> +static int thermal_of_populate_trip(struct device_node *np,
>> +				    struct __thermal_trip *trip)
>> +{
>> +	int prop;
>> +	int ret;
>> +
>> +	ret = of_property_read_u32(np, "temperature", &prop);
>> +	if (ret < 0) {
>> +		pr_err("missing temperature property\n");
>> +		return ret;
>> +	}
>> +	trip->temperature = prop;
>> +
>> +	ret = of_property_read_u32(np, "hysteresis", &prop);
>> +	if (ret < 0) {
>> +		pr_err("missing hysteresis property\n");
>> +		return ret;
>> +	}
>> +	trip->hysteresis = prop;
>> +
>> +	ret = of_property_read_u32(np, "type", &prop);
>> +	if (ret < 0) {
>> +		pr_err("missing type property\n");
>> +		return ret;
>> +	}
>> +	trip->type = prop;
>> +
>> +	/* Required for cooling attachment matching */
>> +	trip->np = np;
>> +
>> +	return 0;
>> +}
>> +
>> +/**
>> + * thermal_of_build_thermal_zone - parse and fill one thermal zone data
>> + * @np: DT node containing a thermal zone node
>> + *
>> + * This function parses a thermal zone type of node represented by
>> + * @np parameter and fills the read data into a __thermal_zone data structure
>> + * and return this pointer.
>> + *
>> + * Return: On success returns a valid struct __thermal_zone,
>> + * otherwise, it returns a corresponding ERR_PTR(). Caller must
>> + * check the return value with help of IS_ERR() helper.
>> + */
>> +static struct __thermal_zone *
>> +thermal_of_build_thermal_zone(struct device_node *np)
>> +{
>> +	struct device_node *child, *gchild;
>> +	struct __thermal_zone *tz;
>> +	int ret, i;
>> +	u32 prop;
>> +
>> +	if (!np) {
>> +		pr_err("no thermal zone np\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
>> +	if (!tz) {
>> +		pr_err("not enough memory for thermal of zone\n");
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "passive-delay", &prop);
>> +	if (ret < 0) {
>> +		pr_err("missing passive_delay property\n");
>> +		return ERR_PTR(ret);
>> +	}
>> +	tz->passive_delay = prop;
>> +
>> +	ret = of_property_read_u32(np, "polling-delay", &prop);
>> +	if (ret < 0) {
>> +		pr_err("missing polling_delay property\n");
>> +		return ERR_PTR(ret);
>> +	}
>> +	tz->polling_delay = prop;
>> +
>> +	/* trips */
>> +	child = of_get_child_by_name(np, "trips");
>> +
>> +	/* No trips provided */
>> +	if (!child)
>> +		goto finish;
>> +
>> +	tz->ntrips = of_get_child_count(child);
>> +	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
>> +	if (!tz->trips)
>> +		return ERR_PTR(-ENOMEM);
>> +	i = 0;
>> +	for_each_child_of_node(child, gchild)
>> +		thermal_of_populate_trip(gchild, &tz->trips[i++]);
>> +
>> +	of_node_put(child);
>> +
>> +	/* cooling-attachments */
>> +	child = of_get_child_by_name(np, "cooling-attachments");
>> +
>> +	/* cooling-attachments provided */
>> +	if (!child)
>> +		goto finish;
>> +
>> +	tz->num_tbps = of_get_child_count(child);
>> +	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
>> +	if (!tz->tbps)
>> +		return ERR_PTR(-ENOMEM);
>> +	i = 0;
>> +	for_each_child_of_node(child, gchild)
>> +		thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
>> +						tz->trips, tz->ntrips);
>> +
>> +finish:
>> +	tz->mode = THERMAL_DEVICE_DISABLED;
>> +
>> +	return tz;
>> +}
>> +
>> +/**
>> + * of_parse_thermal_zones - parse device tree thermal data
>> + *
>> + * Initialization function that can be called by machine initialization
>> + * code to parse thermal data and populate the thermal framework
>> + * with hardware thermal zones info. This function only parses thermal zones.
>> + * Cooling devices and sensor devices nodes are supposed to be parsed
>> + * by their respective drivers.
>> + *
>> + * Return: 0 on success, proper error code otherwise
>> + *
>> + */
>> +int __init of_parse_thermal_zones(void)
>> +{
>> +	struct device_node *np, *child;
>> +	struct __thermal_zone *tz;
>> +	struct thermal_zone_device_ops *ops;
>> +
>> +	np = of_find_node_by_name(NULL, "thermal-zones");
>> +	if (!np) {
>> +		pr_err("unable to find thermal zones\n");
>> +		return 0;
>> +	}
>> +
>> +	for_each_child_of_node(np, child) {
>> +		struct thermal_zone_device *zone;
>> +		struct thermal_zone_params *tzp;
>> +
>> +		tz = thermal_of_build_thermal_zone(child);
>> +		if (IS_ERR(tz)) {
>> +			pr_err("failed to build thermal zone %ld\n",
>> +			       PTR_ERR(tz));
>> +			return 0;
>> +		}
>> +
>> +		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
>> +		if (!ops) {
>> +			pr_err("no memory available for thermal ops\n");
>> +			return 0;
>> +		}
>> +		memcpy(ops, &of_thermal_ops, sizeof(*ops));
>> +
>> +		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
>> +		if (!ops) {
>> +			pr_err("no memory available for thermal zone params\n");
>> +			return 0;
>> +		}
>> +		/* No hwmon because there might be hwmon drivers registering */
>> +		tzp->no_hwmon = true;
>> +
>> +		zone = thermal_zone_device_register(child->name, tz->ntrips,
>> +						    0, tz,
>> +						    ops, tzp,
>> +						    tz->passive_delay,
>> +						    tz->polling_delay);
>> +		if (IS_ERR(zone))
>> +			pr_err("Failed to build %s zone %ld\n", child->name,
>> +			       PTR_ERR(zone));
>> +	}
>> +	return 0;
>> +}
>> +
>> +/**
>> + * of_thermal_destroy_zones - remove all zones parsed and allocated resources
>> + *
>> + * Finds all zones parsed and added to the thermal framework and remove them
>> + * from the system, together with their resources.
>> + *
>> + */
>> +void __exit of_thermal_destroy_zones(void)
>> +{
>> +	struct device_node *np, *child;
>> +	struct __thermal_zone *tz;
>> +
>> +	np = of_find_node_by_name(NULL, "thermal-zones");
>> +	if (!np) {
>> +		pr_err("unable to find thermal zones\n");
>> +		return;
>> +	}
>> +
>> +	for_each_child_of_node(np, child) {
>> +		struct thermal_zone_device *zone;
>> +
>> +		zone = thermal_zone_get_zone_by_name(child->name);
>> +		if (IS_ERR(zone))
>> +			continue;
>> +
>> +		thermal_zone_device_unregister(zone);
>> +		kfree(zone->tzp);
>> +		kfree(zone->ops);
>> +		tz = zone->devdata;
>> +		kfree(tz->tbps);
>> +		kfree(tz->trips);
>> +		kfree(tz);
>> +	}
>> +}
>> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
>> index 8a94300..a733241 100644
>> --- a/drivers/thermal/thermal_core.c
>> +++ b/drivers/thermal/thermal_core.c
>> @@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
>>   */
>>  struct thermal_zone_device *thermal_zone_device_register(const char *type,
>>  	int trips, int mask, void *devdata,
>> -	const struct thermal_zone_device_ops *ops,
>> +	struct thermal_zone_device_ops *ops,
>>  	const struct thermal_zone_params *tzp,
>>  	int passive_delay, int polling_delay)
>>  {
>> @@ -1751,8 +1751,14 @@ static int __init thermal_init(void)
>>  	if (result)
>>  		goto unregister_class;
>>  
>> +	result = of_parse_thermal_zones();
>> +	if (result)
>> +		goto exit_netlink;
>> +
>>  	return 0;
>>  
>> +exit_netlink:
>> +	genetlink_exit();
>>  unregister_governors:
>>  	thermal_unregister_governors();
>>  unregister_class:
>> @@ -1768,6 +1774,7 @@ error:
>>  
>>  static void __exit thermal_exit(void)
>>  {
>> +	of_thermal_destroy_zones();
>>  	genetlink_exit();
>>  	class_unregister(&thermal_class);
>>  	thermal_unregister_governors();
>> diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
>> index 7cf2f66..3db339f 100644
>> --- a/drivers/thermal/thermal_core.h
>> +++ b/drivers/thermal/thermal_core.h
>> @@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
>>  static inline void thermal_gov_user_space_unregister(void) {}
>>  #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
>>  
>> +/* device tree support */
>> +#ifdef CONFIG_THERMAL_OF
>> +int of_parse_thermal_zones(void);
>> +void of_thermal_destroy_zones(void);
>> +#else
>> +static inline int of_parse_thermal_zones(void) { return 0; }
>> +static inline void of_thermal_destroy_zones(void) { }
>> +#endif
>> +
>>  #endif /* __THERMAL_CORE_H__ */
>> diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h
>> new file mode 100644
>> index 0000000..6dd6ccd
>> --- /dev/null
>> +++ b/include/dt-bindings/thermal/thermal.h
>> @@ -0,0 +1,27 @@
>> +/*
>> + * This header provides constants for most thermal bindings.
>> + *
>> + * Copyright (C) 2013 Texas Instruments
>> + *	Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>> + *
>> + * GPLv2 only
>> + */
>> +
>> +#ifndef _DT_BINDINGS_THERMAL_THERMAL_H
>> +#define _DT_BINDINGS_THERMAL_THERMAL_H
>> +
>> +/*
>> + * Here are the thermal trip types. This must
>> + * match with enum thermal_trip_type at
>> + * include/linux/thermal.h
>> + */
>> +#define THERMAL_TRIP_ACTIVE		0
>> +#define THERMAL_TRIP_PASSIVE		1
>> +#define THERMAL_TRIP_HOT		2
>> +#define THERMAL_TRIP_CRITICAL		3
>> +
>> +/* On cooling devices upper and lower limits */
>> +#define THERMAL_NO_LIMIT		(-1UL)
>> +
>> +#endif
>> +
>> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
>> index b268d3c..b780c5b 100644
>> --- a/include/linux/thermal.h
>> +++ b/include/linux/thermal.h
>> @@ -143,6 +143,7 @@ struct thermal_cooling_device {
>>  	int id;
>>  	char type[THERMAL_NAME_LENGTH];
>>  	struct device device;
>> +	struct device_node *np;
>>  	void *devdata;
>>  	const struct thermal_cooling_device_ops *ops;
>>  	bool updated; /* true if the cooling device does not need update */
>> @@ -172,7 +173,7 @@ struct thermal_zone_device {
>>  	int emul_temperature;
>>  	int passive;
>>  	unsigned int forced_passive;
>> -	const struct thermal_zone_device_ops *ops;
>> +	struct thermal_zone_device_ops *ops;
>>  	const struct thermal_zone_params *tzp;
>>  	struct thermal_governor *governor;
>>  	struct list_head thermal_instances;
>> @@ -242,8 +243,31 @@ struct thermal_genl_event {
>>  };
>>  
>>  /* Function declarations */
>> +#ifdef CONFIG_THERMAL_OF
>> +struct thermal_zone_device *
>> +thermal_zone_of_sensor_register(struct device *dev, int id,
>> +				void *data, int (*get_temp)(void *, long *),
>> +				int (*get_trend)(void *, long *));
>> +void thermal_zone_of_sensor_unregister(struct device *dev,
>> +				       struct thermal_zone_device *tz);
>> +#else
>> +static inline struct thermal_zone_device *
>> +thermal_zone_of_sensor_register(struct device *dev, int id,
>> +				void *data, int (*get_temp)(void *, long *),
>> +				int (*get_trend)(void *, long *))
>> +{
>> +	return NULL;
>> +}
>> +
>> +static inline
>> +void thermal_zone_of_sensor_unregister(struct device *dev,
>> +				       struct thermal_zone_device *tz)
>> +{
>> +}
>> +
>> +#endif
>>  struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
>> -		void *, const struct thermal_zone_device_ops *,
>> +		void *, struct thermal_zone_device_ops *,
>>  		const struct thermal_zone_params *, int, int);
>>  void thermal_zone_device_unregister(struct thermal_zone_device *);
>>  
>> -- 
>> 1.8.2.1.342.gfa7285d
>>
>>
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 295 bytes --]

[PATCHv3 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

This patch introduces a device tree bindings for
describing the hardware thermal behavior and limits.
Also a parser to read and interpret the data and feed
it in the thermal framework is presented.

This patch introduces a thermal data parser for device
tree. The parsed data is used to build thermal zones
and thermal binding parameters. The output data
can then be used to deploy thermal policies.

This patch adds also documentation regarding this
API and how to define tree nodes to use
this infrastructure.

Note that, in order to be able to have control
on the sensor registration on the DT thermal zone,
it was required to allow changing the thermal zone
.get_temp callback. For this reason, this patch
also removes the 'const' modifier from the .ops
field of thermal zone devices.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 .../devicetree/bindings/thermal/thermal.txt        | 498 ++++++++++++++
 drivers/thermal/Kconfig                            |  13 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/of-thermal.c                       | 758 +++++++++++++++++++++
 drivers/thermal/thermal_core.c                     |   9 +-
 drivers/thermal/thermal_core.h                     |   9 +
 include/dt-bindings/thermal/thermal.h              |  27 +
 include/linux/thermal.h                            |  28 +-
 8 files changed, 1340 insertions(+), 3 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt
 create mode 100644 drivers/thermal/of-thermal.c
 create mode 100644 include/dt-bindings/thermal/thermal.h
---

Hello all,

Here is yet another version with very minor change. The
third version of this code now includes a check for
NULL parameters in the sensor unregister API, as requested
by Guenter.

Eduardo

diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
new file mode 100644
index 0000000..6664533
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/thermal.txt
@@ -0,0 +1,498 @@
+* Thermal Framework Device Tree descriptor
+
+Generic binding to provide a way of defining hardware thermal
+structure using device tree. A thermal structure includes thermal
+zones and their components, such as trip points, polling intervals,
+sensors and cooling devices binding descriptors.
+
+The target of device tree thermal descriptors is to describe only
+the hardware thermal aspects, not how the system must control or which
+algorithm or policy must be taken in place.
+
+There are five types of nodes involved to describe thermal bindings:
+- sensors: used to describe the device source of temperature sensing;
+- cooling devices: used to describe devices source of power dissipation control;
+- trip points: used to describe points in temperature domain defined to
+make the system aware of hardware limits;
+- cooling attachments: used to describe links between trip points and
+cooling devices;
+- thermal zones: used to describe thermal data within the hardware;
+
+It follows a description of each type of these device tree nodes.
+
+* Sensor devices
+
+Sensor devices are nodes providing temperature sensing capabilities on thermal
+zones. Typical devices are I2C ADC converters and bandgaps. Theses are nodes
+providing temperature data to thermal zones. Temperature sensor devices may
+control one or more internal sensors.
+
+Required property:
+- #sensor-cells:	Used to provide sensor device specific information
+			while referring to it. Must be at least 1, in order
+			to identify uniquely the sensor instances within
+			the IC. See thermal zone binding for more details
+			on how consumers refer to sensor devices.
+
+* Cooling device nodes
+
+Cooling devices are nodes providing control on power dissipation. There
+are essentially two ways to provide control on power dissipation. First
+is by means of regulating device performance, which is known as passive
+cooling. Second is by means of activating devices in order to remove
+the dissipated heat, which is known as active cooling, e.g. regulating
+fan speeds. In both cases, cooling devices shall have a way to determine
+the level of cooling.
+
+Required property:
+- cooling-min-level:	A unsigned integer indicating the smallest
+			cooling level accepted. Typically 0.
+- cooling-max-level:	An unsigned integer indicating the largest
+			cooling level accepted.
+- #cooling-cells:	Used to provide cooling device specific information
+			while referring to it. Must be at least 2, in order
+			to specify minimum and maximum cooling level used
+			in the reference. See Cooling device attachments section
+			below for more details on how consumers refer to
+			cooling devices.
+
+* Trip points
+
+The trip node is a node to describe a point in the temperature domain
+in which the system takes an action. This node describes just the point,
+not the action.
+
+Required properties:
+- temperature:		the trip temperature level, in milliCelsius.
+- hysteresis:		a (low) hysteresis value on 'temperature'. This is a
+			relative value, in milliCelsius.
+- type:			the trip type. Here is the type mapping:
+	THERMAL_TRIP_ACTIVE	0:	A trip point to enable active cooling
+	THERMAL_TRIP_PASSIVE	1:	A trip point to enable passive cooling
+	THERMAL_TRIP_HOT	2:	A trip point to notify emergency
+	THERMAL_TRIP_CRITICAL	3:	Hardware not reliable.
+
+Refer to include/dt-bindings/thermal/thermal.h for definition of these consts.
+
+* Cooling device attachments
+
+The cooling device attachments node is a node to describe how cooling devices
+get assigned to trip points of the zone. The cooling devices are expected
+to be loaded in the target system.
+
+Required properties:
+- cooling-device:	A phandle of a cooling device with its parameters,
+			referring to which cooling device is used in this
+			binding. The required parameters are: the minimum
+			cooling level and the maximum cooling level used
+			in this attach.
+- trip:			A phandle of a trip point node within the same thermal
+			zone.
+
+Optional property:
+- contribution:		The cooling contribution to the thermal zone of the
+			referred cooling device at the referred trip point.
+			The contribution is a value from 0 to 100. The sum
+			of all cooling contributions within a thermal zone
+			must never exceed 100.
+
+Note: Using the THERMAL_NO_LIMIT (-1L) constant in the cooling-device phandle
+limit parameters means:
+(i)   - minimum level allowed for minimum cooling level used in the reference.
+(ii)  - maximum level allowed for maximum cooling level used in the reference.
+Refer to include/dt-bindings/thermal/thermal.h for definition of this constant.
+
+* Thermal zones
+
+The thermal-zone node is the node containing all the required info
+for describing a thermal zone, including its cdev bindings. The thermal_zone
+node must contain, apart from its own properties, one node containing
+trip nodes and one node containing all the zone cooling attachments.
+
+Required properties:
+- passive-delay:	The maximum number of milliseconds to wait between polls
+			when performing passive cooling.
+- polling-delay:	The maximum number of milliseconds to wait between polls
+			when checking this thermal zone.
+- sensors:		A list of sensor phandles and their parameters. The
+			required parameter is the sensor id, in order to
+			identify internal sensors when the sensor IC features
+			several sensing units.
+- trips:		A sub-node containing several trip point nodes required
+			to describe the thermal zone.
+- cooling-attachments	A sub-node containing several cooling device attaches
+			nodes, used to describe the relation between trips
+			and cooling devices.
+
+Optional property:
+- coefficients:		An array of integers (one signed cell) containing
+			coefficients to compose a linear relation between
+			the sensors described in the sensors property.
+			Coefficients defaults to 1, in case this property
+			is not specified. A simple linear polynomial is used:
+			Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
+
+			The coefficients are ordered and they match with sensors
+			by means of sensor ID. Additional coefficients are
+			interpreted as constant offsets.
+
+Note: The delay properties are bound to the maximum dT/dt (temperature
+derivative over time) in two situations for a thermal zone:
+(i)  - when active cooling is activated (passive-delay); and
+(ii) - when the zone just needs to be monitored (polling-delay).
+The maximum dT/dt is highly bound to hardware power consumption and dissipation
+capability.
+
+* Examples
+
+Below are several examples on how to use thermal data descriptors
+using device tree bindings:
+
+(a) - CPU thermal zone
+
+The CPU thermal zone example below describes how to setup one thermal zone
+using one single sensor as temperature source and many cooling devices and
+power dissipation control sources.
+
+#include <dt-bindings/thermal/thermal.h>
+
+cpus {
+	cpu0: cpu@0 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <3>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+	...
+};
+
+&i2c1 {
+	...
+	fan0: fan@0x48 {
+		...
+		cooling-min-level = <0>;
+		cooling-max-level = <9>;
+		#cooling-cells = <2>; /* min followed by max */
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+                cpu-alert0: cpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_ACTIVE>;
+                };
+                cpu-alert1: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-alert0>;
+			cooling-device = <&fan0 THERMAL_NO_LIMITS 4>;
+		};
+		attach1 {
+			trip = <&cpu-alert1>;
+			cooling-device = <&fan0 5 THERMAL_NO_LIMITS>;
+		};
+		attach2 {
+			trip = <&cpu-alert1>;
+			cooling-device =
+				<&cpu0 THERMAL_NO_LIMITS THERMAL_NO_LIMITS>;
+		};
+	};
+};
+
+In the example above, the ADC sensor at address 0x0000ED00 is used to monitor
+the zone 'cpu-thermal' using its the sensor 0. The fan0, a fan device controlled
+via I2C bus 1, at adress 0x48, is used to remove the heat out of the thermal
+zone 'cpu-thermal' using its cooling levels from its minimum to 4, when it
+reaches trip point 'cpu-alert0' at 90C, as an example of active cooling. The
+same cooling device is used at 'cpu-alert1', but from 5 to its maximum level.
+The cpu@0 device is also linked to the same thermal zone, 'cpu-thermal', as a
+passive cooling device, using all its cooling levels at trip point 'cpu-alert1',
+which is a trip point at 100C.
+
+(b) - IC with several internal sensors
+
+The example below describes how to deploy several thermal zones based off a
+single sensor IC, assuming it has several internal sensors. This is a common
+case on SoC designs with several internal IPs that may need different thermal
+requirements, and thus may have their own sensor to monitor or detect internal
+hotspots in their silicon.
+
+#include <dt-bindings/thermal/thermal.h>
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     0>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                cpu-alert: cpu-alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu-crit: cpu-crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+gpu-thermal: gpu-thermal {
+	passive-delay = <120>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     1>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                gpu-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                gpu-crit: gpu-crit {
+                        temperature = <105000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+dsp-thermal: dsp-thermal {
+	passive-delay = <50>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0     2>;
+
+        trips {
+		/* each zone within the SoC may have its own trips */
+                dsp-alert: gpu-alert {
+                        temperature = <90000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                dsp-crit: gpu-crit {
+                        temperature = <135000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		/* each zone within the SoC may have its own cooling */
+		...
+	};
+};
+
+In the example above there is one bandgap IC which has the capability to
+monitor three sensors. The hardware has been designed so that sensors are
+placed on different places in the DIE to monitor different temperature
+hotspots: one for CPU thermal zone, one for GPU thermal zone and the
+other to monitor a DSP thermal zone.
+
+Thus, there is a need to assign each sensor provided by the bandgap IC
+to different thermal zones. This is achieved by means of using the
+#sensor-cells property and using the first parameter as sensor ID.
+In the example, then, bandgap.sensor0 is used to monitor CPU thermal zone,
+bandgap.sensor1 is used to monitor GPU thermal zone and bandgap.sensor2
+is used to monitor DSP thermal zone. Each zone may be uncorrelated,
+having its own dT/dt requirements, trips and cooling attachments.
+
+
+(c) - Several sensors within one single thermal zone
+
+The example below illustrates how to use more than one sensor within
+one thermal zone.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc: sensor@0x49 {
+		...
+		#sensor-cells = <1>;
+	};
+};
+
+bandgap0: bandgap@0x0000ED00 {
+	...
+	#sensor-cells = <1>;
+};
+
+cpu-thermal: cpu-thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap0	0>,
+		  <&adc		0>;
+
+		/* hotspot = 100 * bandgap - 120 * adc + 484 */
+	coefficients = 		<100	-120	484>;
+
+        trips {
+		...
+        };
+
+	cooling-attachments {
+		...
+	};
+};
+
+In some cases, there is a need to use more than one sensor to extrapolate
+a thermal hotspot in the silicon. The above example illustrate this situation.
+For instance, it may be the case that a sensor external to CPU IP may be place
+close to CPU hotspot and together with internal CPU sensor, it is used
+to determine the hotspot. The hyppotetical extrapolation rule would be:
+		hotspot = 100 * bandgap - 120 * adc + 484
+
+The same idea can be used to add fixed offset:
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+		hotspot = 1 * adc + 6000
+
+In the above equation, the hotspot is always 6C higher than what is read
+from the sensor ADC. The binding would be then:
+		/* sensor       ID */
+        sensors =  <&adc	0>;
+
+		/* hotspot = 1 * adc + 6000 */
+	coefficients = 		<1	6000>;
+
+(d) - Board thermal
+
+The board thermal example below illustrates how to setup one thermal zone
+with many sensors and many cooling devices.
+
+#include <dt-bindings/thermal/thermal.h>
+
+&i2c1 {
+	...
+	adc-dummy: sensor@0x50 {
+		...
+		#sensor-cells = <1>; /* sensor internal ID */
+	};
+};
+
+batt-thermal {
+	passive-delay = <500>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+	/* sensor       ID */
+	sensors = <&adc-dummy     4>;
+
+	trips {
+		...
+	};
+
+	cooling-attachments {
+		...
+	};
+};
+
+board-thermal: board-thermal {
+	passive-delay = <1000>; /* milliseconds */
+	polling-delay = <2500>; /* milliseconds */
+
+		/* sensor       ID */
+	sensors = <&adc-dummy     0>,
+		  <&adc-dummy     1>,
+		  <&adc-dymmy     2>;
+			/*
+			 * An array of coefficients describing the sensor
+			 * linear relation. E.g.:
+			 * z = c1*x1 + c2*x2 + c3*x3
+			 */
+	coefficients =		<1200	-345	890>;
+
+	trips {
+		/* Trips are based on resulting linear equation */
+		cpu-trip: cpu-trip {
+			temperature = <60000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		gpu-trip: gpu-trip {
+			temperature = <55000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		}
+		lcd-trip: lcp-trip {
+			temperature = <53000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_PASSIVE>;
+		};
+		crit-trip: crit-trip {
+			temperature = <68000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_CRITICAL>;
+		};
+	};
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu-trip>;
+			cooling-device = <&cpu0 0 2>;
+			contribution = <55>;
+		};
+		attach1 {
+			trip = <&gpu-trip>;
+			cooling-device = <&gpu0 0 2>;
+			contribution = <20>;
+		};
+		attach2 {
+			trip = <&lcd-trip>;
+			cooling-device = <&lcd0 5 10>;
+			contribution = <15>;
+		};
+	};
+};
+
+The above example is a mix of previous examples, a sensor IP with several internal
+sensors used to monitor different zones, one of them is composed by several sensors and
+with different cooling devices.
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index dbfc390..dd81eb8 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -29,6 +29,19 @@ config THERMAL_HWMON
 	  Say 'Y' here if you want all thermal sensors to
 	  have hwmon sysfs interface too.
 
+config THERMAL_OF
+	bool
+	prompt "APIs to parse thermal data out of device tree"
+	depends on OF
+	default y
+	help
+	  This options provides helpers to add the support to
+	  read and parse thermal data definitions out of the
+	  device tree blob.
+
+	  Say 'Y' here if you need to build thermal infrastructure
+	  based on device tree.
+
 choice
 	prompt "Default Thermal governor"
 	default THERMAL_DEFAULT_GOV_STEP_WISE
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 584b363..4b03956 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
 
 # interface to/from other layers providing sensors
 thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
+thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
 
 # governors
 thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
new file mode 100644
index 0000000..e895fa4
--- /dev/null
+++ b/drivers/thermal/of-thermal.c
@@ -0,0 +1,758 @@
+/*
+ *  of-thermal.c - Generic Thermal Management device tree support.
+ *
+ *  Copyright (C) 2013 Texas Instruments
+ *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/string.h>
+
+/***   Private data structures to represent thermal device tree data ***/
+
+/**
+ * struct __thermal_trip - representation of a point in temperature domain
+ * @np: pointer to struct device_node that this trip point was created from
+ * @temperature: temperature value in miliCelsius
+ * @hysteresis: relative hysteresis in miliCelsius
+ * @type: trip point type
+ */
+
+struct __thermal_trip {
+	struct device_node *np;
+	unsigned long int temperature;
+	unsigned long int hysteresis;
+	enum thermal_trip_type type;
+};
+
+/**
+ * struct __thermal_bind_param - a match between trip and cooling device
+ * @cooling_device: a pointer to identify the referred cooling device
+ * @trip_id: the trip point index
+ * @usage: the percentage (from 0 to 100) of cooling contribution
+ * @min: minimum cooling level used at this trip point
+ * @max: maximum cooling level used at this trip point
+ */
+
+struct __thermal_bind_params {
+	struct device_node *cooling_device;
+	unsigned int trip_id;
+	unsigned int usage;
+	unsigned long min;
+	unsigned long max;
+};
+
+/**
+ * struct __thermal_zone - internal representation of a thermal zone
+ * @mode: current thermal zone device mode (enabled/disabled)
+ * @passive_delay: polling interval while passive cooling is activated
+ * @polling_delay: zone polling interval
+ * @ntrips: number of trip points
+ * @trips: an array of trip points (0..ntrips - 1)
+ * @num_tbps: number of thermal bind params
+ * @tbps: an array of thermal bind params (0..num_tbps - 1)
+ * @sensor_data: sensor private data used while reading temperature and trend
+ * @get_temp: sensor callback to read temperature
+ * @get_trend: sensor callback to read temperature trend
+ */
+
+struct __thermal_zone {
+	enum thermal_device_mode mode;
+	int passive_delay;
+	int polling_delay;
+
+	/* trip data */
+	int ntrips;
+	struct __thermal_trip *trips;
+
+	/* cooling binding data */
+	int num_tbps;
+	struct __thermal_bind_params *tbps;
+
+	/* sensor interface */
+	void *sensor_data;
+	int (*get_temp)(void *, long *);
+	int (*get_trend)(void *, long *);
+};
+
+/***   DT thermal zone device callbacks   ***/
+
+static int of_thermal_get_temp(struct thermal_zone_device *tz,
+			       unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (!data->get_temp)
+		return -EINVAL;
+
+	return data->get_temp(data->sensor_data, temp);
+}
+
+static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
+				enum thermal_trend *trend)
+{
+	struct __thermal_zone *data = tz->devdata;
+	long dev_trend;
+	int r;
+
+	if (!data->get_trend)
+		return -EINVAL;
+
+	r = data->get_trend(data->sensor_data, &dev_trend);
+	if (r)
+		return r;
+
+	if (dev_trend > 0)
+		*trend = THERMAL_TREND_RAISING;
+	else if (dev_trend < 0)
+		*trend = THERMAL_TREND_DROPPING;
+	else
+		*trend = THERMAL_TREND_STABLE;
+
+	return 0;
+}
+
+static int of_thermal_bind(struct thermal_zone_device *thermal,
+			   struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to bind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_bind_cooling_device(thermal,
+						tbp->trip_id, cdev,
+						tbp->min,
+						tbp->max);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_unbind(struct thermal_zone_device *thermal,
+			     struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to unbind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_unbind_cooling_device(thermal,
+						tbp->trip_id, cdev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_get_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode *mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	*mode = data->mode;
+
+	return 0;
+}
+
+static int of_thermal_set_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	mutex_lock(&tz->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		tz->polling_delay = data->polling_delay;
+	else
+		tz->polling_delay = 0;
+
+	mutex_unlock(&tz->lock);
+
+	data->mode = mode;
+	thermal_zone_device_update(tz);
+
+	return 0;
+}
+
+static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
+				    enum thermal_trip_type *type)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*type = data->trips[trip].type;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*temp = data->trips[trip].temperature;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].temperature = temp;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long *hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*hyst = data->trips[trip].hysteresis;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal fw should take care of data->mask & (1 << trip) */
+	data->trips[trip].hysteresis = hyst;
+
+	return 0;
+}
+
+static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+	int i;
+
+	for (i = 0; i < data->ntrips; i++)
+		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = data->trips[i].temperature;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static struct thermal_zone_device_ops of_thermal_ops = {
+	.get_mode = of_thermal_get_mode,
+	.set_mode = of_thermal_set_mode,
+
+	.get_trip_type = of_thermal_get_trip_type,
+	.get_trip_temp = of_thermal_get_trip_temp,
+	.set_trip_temp = of_thermal_set_trip_temp,
+	.get_trip_hyst = of_thermal_get_trip_hyst,
+	.set_trip_hyst = of_thermal_set_trip_hyst,
+	.get_crit_temp = of_thermal_get_crit_temp,
+
+	.bind = of_thermal_bind,
+	.unbind = of_thermal_unbind,
+};
+
+/***   sensor API   ***/
+
+static struct thermal_zone_device *
+thermal_zone_of_add_sensor(struct device_node *zone,
+			   struct device_node *sensor, void *data,
+			   int (*get_temp)(void *, long *),
+			   int (*get_trend)(void *, long *))
+{
+	struct thermal_zone_device *tzd;
+	struct __thermal_zone *tz;
+
+	tzd = thermal_zone_get_zone_by_name(zone->name);
+	if (IS_ERR(tzd))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	tz = tzd->devdata;
+
+	mutex_lock(&tzd->lock);
+	tz->get_temp = get_temp;
+	tz->get_trend = get_trend;
+	tz->sensor_data = data;
+
+	tzd->ops->get_temp = of_thermal_get_temp;
+	tzd->ops->get_trend = of_thermal_get_trend;
+	mutex_unlock(&tzd->lock);
+
+	return tzd;
+}
+
+/**
+ * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @sensor_id: a sensor identifier, in case the sensor IP has more
+ *             than one sensors
+ * @data: a private pointer (owned by the caller) that will be passed
+ *        back, when a temperature reading is needed.
+ * @get_temp: a pointer to a function that reads the sensor temperature.
+ * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ *
+ * This function will search the list of thermal zones described in device
+ * tree and look for the zone that refer to the sensor device pointed by
+ * @dev->of_node as temperature providers. For the zone pointing to the
+ * sensor node, the sensor will be added to the DT thermal zone device.
+ *
+ * The thermal zone temperature is provided by the @get_temp function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * The thermal zone temperature trend is provided by the @get_trend function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * TODO:
+ * 01 - This function must enqueue the new sensor instead of using
+ * it as the only source of temperature values.
+ *
+ * 02 - There must be a way to match the sensor with all thermal zones
+ * that refer to it.
+ *
+ * Return: On success returns a valid struct thermal_zone_device,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	struct device_node *np, *child, *sensor_np;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np)
+		return ERR_PTR(-ENODEV);
+
+	if (!dev || !dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	sensor_np = dev->of_node;
+
+	for_each_child_of_node(np, child) {
+		struct of_phandle_args sensor_specs;
+		int ret;
+
+		/* For now, thermal framework supports only 1 sensor per zone */
+		ret = of_parse_phandle_with_args(child, "sensors",
+						 "#sensor-cells",
+						 0, &sensor_specs);
+		if (ret)
+			continue;
+
+		if (sensor_specs.args_count < 1)
+			continue;
+
+		if (sensor_specs.np == sensor_np &&
+		    sensor_specs.args[0] == sensor_id) {
+			of_node_put(np);
+			return thermal_zone_of_add_sensor(child, sensor_np,
+							  data,
+							  get_temp,
+							  get_trend);
+		}
+	}
+	of_node_put(np);
+
+	return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
+
+/**
+ * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
+ *
+ * This function removes the sensor callbacks and private data from the
+ * thermal zone device registered with thermal_zone_of_sensor_register()
+ * API. It will also silent the zone by remove the .get_temp() and .get_trend()
+ * thermal zone device callbacks.
+ *
+ * TODO: When the support to several sensors per zone is added, this
+ * function must search the sensor list based on @dev parameter.
+ *
+ */
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tzd)
+{
+	struct __thermal_zone *tz;
+
+	if (!dev || !tzd || !tzd->devdata)
+		return;
+
+	tz = tzd->devdata;
+
+	/* no __thermal_zone, nothing to be done */
+	if (!tz)
+		return;
+
+	mutex_lock(&tzd->lock);
+	tzd->ops->get_temp = NULL;
+	tzd->ops->get_trend = NULL;
+
+	tz->get_temp = NULL;
+	tz->get_trend = NULL;
+	tz->sensor_data = NULL;
+	mutex_unlock(&tzd->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
+
+/***   functions parsing device tree nodes   ***/
+
+/**
+ * thermal_of_populate_bind_params - parse and fill cooling attachment data
+ * @np: DT node containing a cooling-attachment node
+ * @__tbp: data structure to be filled with cooling attachment info
+ * @trips: array of thermal zone trip points
+ * @ntrips: number of trip points inside trips.
+ *
+ * This function parses a cooling-attachment type of node represented by
+ * @np parameter and fills the read data into @__tbp data structure.
+ * It needs the already parsed array of trip points of the thermal zone
+ * in consideration.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_bind_params(struct device_node *np,
+					   struct __thermal_bind_params *__tbp,
+					   struct __thermal_trip *trips,
+					   int ntrips)
+{
+	struct of_phandle_args cooling_spec;
+	struct device_node *trip;
+	int ret, i;
+	u32 prop;
+
+	/* Default weight. Usage is optional */
+	__tbp->usage = 0;
+	ret = of_property_read_u32(np, "usage", &prop);
+	if (ret == 0)
+		__tbp->usage = prop;
+
+	trip = of_parse_phandle(np, "trip", 0);
+	if (!trip) {
+		pr_err("missing trip property\n");
+		return -ENODEV;
+	}
+
+	/* match using device_node */
+	for (i = 0; i < ntrips; i++)
+		if (trip == trips[i].np) {
+			__tbp->trip_id = i;
+			break;
+		}
+
+	if (i == ntrips) {
+		ret = -ENODEV;
+		goto end;
+	}
+
+	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
+					 0, &cooling_spec);
+	if (ret < 0) {
+		pr_err("missing cooling_device property\n");
+		goto end;
+	}
+	__tbp->cooling_device = cooling_spec.np;
+	if (cooling_spec.args_count >= 2) { /* at least min and max */
+		__tbp->min = cooling_spec.args[0];
+		__tbp->max = cooling_spec.args[1];
+	} else {
+		pr_err("wrong reference to cooling device, missing limits\n");
+	}
+
+end:
+	of_node_put(trip);
+
+	return ret;
+}
+
+/**
+ * thermal_of_populate_trip - parse and fill one trip point data
+ * @np: DT node containing a trip point node
+ * @trip: trip point data structure to be filled up
+ *
+ * This function parses a trip point type of node represented by
+ * @np parameter and fills the read data into @trip data structure.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_trip(struct device_node *np,
+				    struct __thermal_trip *trip)
+{
+	int prop;
+	int ret;
+
+	ret = of_property_read_u32(np, "temperature", &prop);
+	if (ret < 0) {
+		pr_err("missing temperature property\n");
+		return ret;
+	}
+	trip->temperature = prop;
+
+	ret = of_property_read_u32(np, "hysteresis", &prop);
+	if (ret < 0) {
+		pr_err("missing hysteresis property\n");
+		return ret;
+	}
+	trip->hysteresis = prop;
+
+	ret = of_property_read_u32(np, "type", &prop);
+	if (ret < 0) {
+		pr_err("missing type property\n");
+		return ret;
+	}
+	trip->type = prop;
+
+	/* Required for cooling attachment matching */
+	trip->np = np;
+
+	return 0;
+}
+
+/**
+ * thermal_of_build_thermal_zone - parse and fill one thermal zone data
+ * @np: DT node containing a thermal zone node
+ *
+ * This function parses a thermal zone type of node represented by
+ * @np parameter and fills the read data into a __thermal_zone data structure
+ * and return this pointer.
+ *
+ * Return: On success returns a valid struct __thermal_zone,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+static struct __thermal_zone *
+thermal_of_build_thermal_zone(struct device_node *np)
+{
+	struct device_node *child, *gchild;
+	struct __thermal_zone *tz;
+	int ret, i;
+	u32 prop;
+
+	if (!np) {
+		pr_err("no thermal zone np\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
+	if (!tz) {
+		pr_err("not enough memory for thermal of zone\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ret = of_property_read_u32(np, "passive-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing passive_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->passive_delay = prop;
+
+	ret = of_property_read_u32(np, "polling-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing polling_delay property\n");
+		return ERR_PTR(ret);
+	}
+	tz->polling_delay = prop;
+
+	/* trips */
+	child = of_get_child_by_name(np, "trips");
+
+	/* No trips provided */
+	if (!child)
+		goto finish;
+
+	tz->ntrips = of_get_child_count(child);
+	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
+	if (!tz->trips)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_trip(gchild, &tz->trips[i++]);
+
+	of_node_put(child);
+
+	/* cooling-attachments */
+	child = of_get_child_by_name(np, "cooling-attachments");
+
+	/* cooling-attachments provided */
+	if (!child)
+		goto finish;
+
+	tz->num_tbps = of_get_child_count(child);
+	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
+	if (!tz->tbps)
+		return ERR_PTR(-ENOMEM);
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
+						tz->trips, tz->ntrips);
+
+finish:
+	tz->mode = THERMAL_DEVICE_DISABLED;
+
+	return tz;
+}
+
+/**
+ * of_parse_thermal_zones - parse device tree thermal data
+ *
+ * Initialization function that can be called by machine initialization
+ * code to parse thermal data and populate the thermal framework
+ * with hardware thermal zones info. This function only parses thermal zones.
+ * Cooling devices and sensor devices nodes are supposed to be parsed
+ * by their respective drivers.
+ *
+ * Return: 0 on success, proper error code otherwise
+ *
+ */
+int __init of_parse_thermal_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+	struct thermal_zone_device_ops *ops;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return 0;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+		struct thermal_zone_params *tzp;
+
+		tz = thermal_of_build_thermal_zone(child);
+		if (IS_ERR(tz)) {
+			pr_err("failed to build thermal zone %ld\n",
+			       PTR_ERR(tz));
+			return 0;
+		}
+
+		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal ops\n");
+			return 0;
+		}
+		memcpy(ops, &of_thermal_ops, sizeof(*ops));
+
+		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
+		if (!ops) {
+			pr_err("no memory available for thermal zone params\n");
+			return 0;
+		}
+		/* No hwmon because there might be hwmon drivers registering */
+		tzp->no_hwmon = true;
+
+		zone = thermal_zone_device_register(child->name, tz->ntrips,
+						    0, tz,
+						    ops, tzp,
+						    tz->passive_delay,
+						    tz->polling_delay);
+		if (IS_ERR(zone))
+			pr_err("Failed to build %s zone %ld\n", child->name,
+			       PTR_ERR(zone));
+	}
+	return 0;
+}
+
+/**
+ * of_thermal_destroy_zones - remove all zones parsed and allocated resources
+ *
+ * Finds all zones parsed and added to the thermal framework and remove them
+ * from the system, together with their resources.
+ *
+ */
+void __exit of_thermal_destroy_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+
+		zone = thermal_zone_get_zone_by_name(child->name);
+		if (IS_ERR(zone))
+			continue;
+
+		thermal_zone_device_unregister(zone);
+		kfree(zone->tzp);
+		kfree(zone->ops);
+		tz = zone->devdata;
+		kfree(tz->tbps);
+		kfree(tz->trips);
+		kfree(tz);
+	}
+}
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 8a94300..a733241 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1371,7 +1371,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
  */
 struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int trips, int mask, void *devdata,
-	const struct thermal_zone_device_ops *ops,
+	struct thermal_zone_device_ops *ops,
 	const struct thermal_zone_params *tzp,
 	int passive_delay, int polling_delay)
 {
@@ -1751,8 +1751,14 @@ static int __init thermal_init(void)
 	if (result)
 		goto unregister_class;
 
+	result = of_parse_thermal_zones();
+	if (result)
+		goto exit_netlink;
+
 	return 0;
 
+exit_netlink:
+	genetlink_exit();
 unregister_governors:
 	thermal_unregister_governors();
 unregister_class:
@@ -1768,6 +1774,7 @@ error:
 
 static void __exit thermal_exit(void)
 {
+	of_thermal_destroy_zones();
 	genetlink_exit();
 	class_unregister(&thermal_class);
 	thermal_unregister_governors();
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 7cf2f66..3db339f 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
 static inline void thermal_gov_user_space_unregister(void) {}
 #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
 
+/* device tree support */
+#ifdef CONFIG_THERMAL_OF
+int of_parse_thermal_zones(void);
+void of_thermal_destroy_zones(void);
+#else
+static inline int of_parse_thermal_zones(void) { return 0; }
+static inline void of_thermal_destroy_zones(void) { }
+#endif
+
 #endif /* __THERMAL_CORE_H__ */
diff --git a/include/dt-bindings/thermal/thermal.h b/include/dt-bindings/thermal/thermal.h
new file mode 100644
index 0000000..6dd6ccd
--- /dev/null
+++ b/include/dt-bindings/thermal/thermal.h
@@ -0,0 +1,27 @@
+/*
+ * This header provides constants for most thermal bindings.
+ *
+ * Copyright (C) 2013 Texas Instruments
+ *	Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * GPLv2 only
+ */
+
+#ifndef _DT_BINDINGS_THERMAL_THERMAL_H
+#define _DT_BINDINGS_THERMAL_THERMAL_H
+
+/*
+ * Here are the thermal trip types. This must
+ * match with enum thermal_trip_type at
+ * include/linux/thermal.h
+ */
+#define THERMAL_TRIP_ACTIVE		0
+#define THERMAL_TRIP_PASSIVE		1
+#define THERMAL_TRIP_HOT		2
+#define THERMAL_TRIP_CRITICAL		3
+
+/* On cooling devices upper and lower limits */
+#define THERMAL_NO_LIMIT		(-1UL)
+
+#endif
+
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index b268d3c..b780c5b 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -143,6 +143,7 @@ struct thermal_cooling_device {
 	int id;
 	char type[THERMAL_NAME_LENGTH];
 	struct device device;
+	struct device_node *np;
 	void *devdata;
 	const struct thermal_cooling_device_ops *ops;
 	bool updated; /* true if the cooling device does not need update */
@@ -172,7 +173,7 @@ struct thermal_zone_device {
 	int emul_temperature;
 	int passive;
 	unsigned int forced_passive;
-	const struct thermal_zone_device_ops *ops;
+	struct thermal_zone_device_ops *ops;
 	const struct thermal_zone_params *tzp;
 	struct thermal_governor *governor;
 	struct list_head thermal_instances;
@@ -242,8 +243,31 @@ struct thermal_genl_event {
 };
 
 /* Function declarations */
+#ifdef CONFIG_THERMAL_OF
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *));
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz);
+#else
+static inline struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	return NULL;
+}
+
+static inline
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tz)
+{
+}
+
+#endif
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
-		void *, const struct thermal_zone_device_ops *,
+		void *, struct thermal_zone_device_ops *,
 		const struct thermal_zone_params *, int, int);
 void thermal_zone_device_unregister(struct thermal_zone_device *);
 
-- 
1.8.2.1.342.gfa7285d

Re: [PATCHv3 02/16] drivers: thermal: introduce device tree parser

[Joe Perches]

On Wed, 2013-09-18 at 15:02 -0400, Eduardo Valentin wrote:
> This patch introduces a device tree bindings for
> describing the hardware thermal behavior and limits.
> Also a parser to read and interpret the data and feed
> it in the thermal framework is presented.

trivial notes:

> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
[]
> +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
> +				enum thermal_trend *trend)
> +{
> +	struct __thermal_zone *data = tz->devdata;
> +	long dev_trend;
> +	int r;
> +
> +	if (!data->get_trend)
> +		return -EINVAL;
> +
> +	r = data->get_trend(data->sensor_data, &dev_trend);
> +	if (r)
> +		return r;
> +
> +	if (dev_trend > 0)
> +		*trend = THERMAL_TREND_RAISING;
> +	else if (dev_trend < 0)
> +		*trend = THERMAL_TREND_DROPPING;
> +	else
> +		*trend = THERMAL_TREND_STABLE;
> +
> +	return 0;
> +}

If readings are within some non zero noise level,
perhaps stable should be returned.

> +static struct __thermal_zone *
> +thermal_of_build_thermal_zone(struct device_node *np)
> +{
> +	struct device_node *child, *gchild;
> +	struct __thermal_zone *tz;
> +	int ret, i;
> +	u32 prop;
> +
> +	if (!np) {
> +		pr_err("no thermal zone np\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
> +	if (!tz) {
> +		pr_err("not enough memory for thermal of zone\n");

Unnecessary OOM message.
All allocs without GFP_NOWARN get a dump_stack()

> +int __init of_parse_thermal_zones(void)
> +{
[]
> +		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
> +		if (!ops) {
> +			pr_err("no memory available for thermal ops\n");
> +			return 0;
> +		}
> +		memcpy(ops, &of_thermal_ops, sizeof(*ops));
> +
> +		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
> +		if (!ops) {
> +			pr_err("no memory available for thermal zone params\n");
> +			return 0;
> +		}

a couple more OOMs.

Re: [PATCHv3 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 2836 bytes --]

Hello Joe,

Thanks for reviewing this code. Couple of replies.

 18-09-2013 15:11, Joe Perches wrote:
> On Wed, 2013-09-18 at 15:02 -0400, Eduardo Valentin wrote:
>> This patch introduces a device tree bindings for
>> describing the hardware thermal behavior and limits.
>> Also a parser to read and interpret the data and feed
>> it in the thermal framework is presented.
> 
> trivial notes:


No issues.

> 
>> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
> []
>> +static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
>> +				enum thermal_trend *trend)
>> +{
>> +	struct __thermal_zone *data = tz->devdata;
>> +	long dev_trend;
>> +	int r;
>> +
>> +	if (!data->get_trend)
>> +		return -EINVAL;
>> +
>> +	r = data->get_trend(data->sensor_data, &dev_trend);
>> +	if (r)
>> +		return r;
>> +
>> +	if (dev_trend > 0)
>> +		*trend = THERMAL_TREND_RAISING;
>> +	else if (dev_trend < 0)
>> +		*trend = THERMAL_TREND_DROPPING;
>> +	else
>> +		*trend = THERMAL_TREND_STABLE;
>> +
>> +	return 0;
>> +}
> 
> If readings are within some non zero noise level,
> perhaps stable should be returned.

Yes, there should be some sort of threshold for temperature trend. But I
am not sure this is the right place to implement this. This type of
feature is in my TODO list, but I am planing to get it done within the
core code of the thermal framework.


> 
>> +static struct __thermal_zone *
>> +thermal_of_build_thermal_zone(struct device_node *np)
>> +{
>> +	struct device_node *child, *gchild;
>> +	struct __thermal_zone *tz;
>> +	int ret, i;
>> +	u32 prop;
>> +
>> +	if (!np) {
>> +		pr_err("no thermal zone np\n");
>> +		return ERR_PTR(-EINVAL);
>> +	}
>> +
>> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
>> +	if (!tz) {
>> +		pr_err("not enough memory for thermal of zone\n");
> 
> Unnecessary OOM message.
> All allocs without GFP_NOWARN get a dump_stack()
> 
>> +int __init of_parse_thermal_zones(void)
>> +{
> []
>> +		ops = kzalloc(sizeof(*ops), GFP_KERNEL);
>> +		if (!ops) {
>> +			pr_err("no memory available for thermal ops\n");
>> +			return 0;
>> +		}
>> +		memcpy(ops, &of_thermal_ops, sizeof(*ops));
>> +
>> +		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
>> +		if (!ops) {
>> +			pr_err("no memory available for thermal zone params\n");
>> +			return 0;
>> +		}
> 
> a couple more OOMs.
> 

Hmmm.. I am pretty sure you have a good point. But to me seams to be
still a common practice to have drivers outputing error messages when
allocation fails. A simple git grep -A 4 kzalloc for instance, shows
that there are still quite a considerable amount of occurrences of such
practice.


> 
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCHv3 02/16] drivers: thermal: introduce device tree parser

[Joe Perches]

On Wed, 2013-09-18 at 15:44 -0400, Eduardo Valentin wrote:
> Hello Joe,

Hello Eduardo.

>  18-09-2013 15:11, Joe Perches wrote:
> > On Wed, 2013-09-18 at 15:02 -0400, Eduardo Valentin wrote:
> >> This patch introduces a device tree bindings for
> >> describing the hardware thermal behavior and limits.
> >> Also a parser to read and interpret the data and feed
> >> it in the thermal framework is presented.
> > 
> > trivial notes:
[]
> > If readings are within some non zero noise level,
> > perhaps stable should be returned.
> 
> Yes, there should be some sort of threshold for temperature trend. But I
> am not sure this is the right place to implement this. This type of
> feature is in my TODO list, but I am planing to get it done within the
> core code of the thermal framework.

No worries, one day...  Just wanted to bring it to attention.

> >> +static struct __thermal_zone *
> >> +thermal_of_build_thermal_zone(struct device_node *np)
> >> +{
[]
> >> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
> >> +	if (!tz) {
> >> +		pr_err("not enough memory for thermal of zone\n");
> > 
> > Unnecessary OOM message.
> > All allocs without GFP_NOWARN get a dump_stack()

[]

> Hmmm.. I am pretty sure you have a good point. But to me seams to be
> still a common practice to have drivers outputing error messages when
> allocation fails. A simple git grep -A 4 kzalloc for instance, shows
> that there are still quite a considerable amount of occurrences of such
> practice.

True though a considerable number have been removed.
I think these should all be deleted eventually and
there's no good reason to add more.

Re: [PATCHv3 02/16] drivers: thermal: introduce device tree parser

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 2060 bytes --]

On 18-09-2013 15:59, Joe Perches wrote:
> On Wed, 2013-09-18 at 15:44 -0400, Eduardo Valentin wrote:
>> Hello Joe,
> 
> Hello Eduardo.
> 
>>  18-09-2013 15:11, Joe Perches wrote:
>>> On Wed, 2013-09-18 at 15:02 -0400, Eduardo Valentin wrote:
>>>> This patch introduces a device tree bindings for
>>>> describing the hardware thermal behavior and limits.
>>>> Also a parser to read and interpret the data and feed
>>>> it in the thermal framework is presented.
>>>
>>> trivial notes:
> []
>>> If readings are within some non zero noise level,
>>> perhaps stable should be returned.
>>
>> Yes, there should be some sort of threshold for temperature trend. But I
>> am not sure this is the right place to implement this. This type of
>> feature is in my TODO list, but I am planing to get it done within the
>> core code of the thermal framework.
> 
> No worries, one day...  Just wanted to bring it to attention.

Thanks, no worries, I should be working on it at some point in near
future. It does not hurt to add a TODO mark above this code though.

> 
>>>> +static struct __thermal_zone *
>>>> +thermal_of_build_thermal_zone(struct device_node *np)
>>>> +{
> []
>>>> +	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
>>>> +	if (!tz) {
>>>> +		pr_err("not enough memory for thermal of zone\n");
>>>
>>> Unnecessary OOM message.
>>> All allocs without GFP_NOWARN get a dump_stack()
> 
> []
> 
>> Hmmm.. I am pretty sure you have a good point. But to me seams to be
>> still a common practice to have drivers outputing error messages when
>> allocation fails. A simple git grep -A 4 kzalloc for instance, shows
>> that there are still quite a considerable amount of occurrences of such
>> practice.
> 
> True though a considerable number have been removed.
> I think these should all be deleted eventually and
> there's no good reason to add more.


I see.  I will repost with your suggestion. Thanks.

> 
> 
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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[PATCH 07/16] thermal: ti-soc-thermal: use thermal DT infrastructure

[Eduardo Valentin]

This patch improves the ti-soc-thermal driver by adding the
support to build the thermal zones based on DT nodes.

The driver will have two options now to build the thermal
zones. The first option is the zones originally coded
in this driver. So, the driver behavior will be same
if there is no DT node describing the zones. The second
option, when it is found a DT node with thermal data,
will used the common infrastructure to build the thermal
zone and bind its cooling devices.

In case the driver loads thermal data using the legacy
mode, this driver still adds to the system
a cpufreq cooling device. Loading the thermal data from
DT, the driver assumes someone else will add the cpufreq
cooling device, like the cpufreq driver.

Cc: Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
---
 drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 77 +++++++++++++++++-----
 1 file changed, 62 insertions(+), 15 deletions(-)

diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
index 4f8b9af..1d373ec 100644
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -31,6 +31,7 @@
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/cpu_cooling.h>
+#include <linux/of.h>
 
 #include "ti-thermal.h"
 #include "ti-bandgap.h"
@@ -44,6 +45,7 @@ struct ti_thermal_data {
 	enum thermal_device_mode mode;
 	struct work_struct thermal_wq;
 	int sensor_id;
+	bool our_zone;
 };
 
 static void ti_thermal_work(struct work_struct *work)
@@ -75,11 +77,10 @@ static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
 
 /* thermal zone ops */
 /* Get temperature callback function for thermal zone*/
-static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
-				      unsigned long *temp)
+static inline int __ti_thermal_get_temp(void *devdata, long *temp)
 {
 	struct thermal_zone_device *pcb_tz = NULL;
-	struct ti_thermal_data *data = thermal->devdata;
+	struct ti_thermal_data *data = devdata;
 	struct ti_bandgap *bgp;
 	const struct ti_temp_sensor *s;
 	int ret, tmp, slope, constant;
@@ -117,6 +118,14 @@ static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
 	return ret;
 }
 
+static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
+				      unsigned long *temp)
+{
+	struct ti_thermal_data *data = thermal->devdata;
+
+	return __ti_thermal_get_temp(data, temp);
+}
+
 /* Bind callback functions for thermal zone */
 static int ti_thermal_bind(struct thermal_zone_device *thermal,
 			   struct thermal_cooling_device *cdev)
@@ -229,11 +238,9 @@ static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	return 0;
 }
 
-/* Get the temperature trend callback functions for thermal zone */
-static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
-				int trip, enum thermal_trend *trend)
+static int __ti_thermal_get_trend(void *p, long *trend)
 {
-	struct ti_thermal_data *data = thermal->devdata;
+	struct ti_thermal_data *data = p;
 	struct ti_bandgap *bgp;
 	int id, tr, ret = 0;
 
@@ -244,6 +251,22 @@ static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
 	if (ret)
 		return ret;
 
+	*trend = tr;
+
+	return 0;
+}
+
+/* Get the temperature trend callback functions for thermal zone */
+static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
+				int trip, enum thermal_trend *trend)
+{
+	int ret;
+	long tr;
+
+	ret = __ti_thermal_get_trend(thermal->devdata, &tr);
+	if (ret)
+		return ret;
+
 	if (tr > 0)
 		*trend = THERMAL_TREND_RAISING;
 	else if (tr < 0)
@@ -307,16 +330,23 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
 	if (!data)
 		return -EINVAL;
 
-	/* Create thermal zone */
-	data->ti_thermal = thermal_zone_device_register(domain,
+	/* in case this is specified by DT */
+	data->ti_thermal = thermal_zone_of_sensor_register(bgp->dev, id,
+					data, __ti_thermal_get_temp,
+					__ti_thermal_get_trend);
+	if (IS_ERR(data->ti_thermal)) {
+		/* Create thermal zone */
+		data->ti_thermal = thermal_zone_device_register(domain,
 				OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,
 				NULL, FAST_TEMP_MONITORING_RATE,
 				FAST_TEMP_MONITORING_RATE);
-	if (IS_ERR(data->ti_thermal)) {
-		dev_err(bgp->dev, "thermal zone device is NULL\n");
-		return PTR_ERR(data->ti_thermal);
+		if (IS_ERR(data->ti_thermal)) {
+			dev_err(bgp->dev, "thermal zone device is NULL\n");
+			return PTR_ERR(data->ti_thermal);
+		}
+		data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
+		data->our_zone = true;
 	}
-	data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
 	ti_bandgap_set_sensor_data(bgp, id, data);
 	ti_bandgap_write_update_interval(bgp, data->sensor_id,
 					data->ti_thermal->polling_delay);
@@ -330,7 +360,13 @@ int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
 
-	thermal_zone_device_unregister(data->ti_thermal);
+	if (data && data->ti_thermal) {
+		if (data->our_zone)
+			thermal_zone_device_unregister(data->ti_thermal);
+		else
+			thermal_zone_of_sensor_unregister(bgp->dev,
+							  data->ti_thermal);
+	}
 
 	return 0;
 }
@@ -349,6 +385,15 @@ int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
 {
 	struct ti_thermal_data *data;
+	struct device_node *np = bgp->dev->of_node;
+
+	/*
+	 * We are assuming here that if one deploys the zone
+	 * using DT, then it must be aware that the cooling device
+	 * loading has to happen via cpufreq driver.
+	 */
+	if (of_find_property(np, "#sensor-cells", NULL))
+		return 0;
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
 	if (!data || IS_ERR(data))
@@ -379,7 +424,9 @@ int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
 	struct ti_thermal_data *data;
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
-	cpufreq_cooling_unregister(data->cool_dev);
+
+	if (data && data->cool_dev)
+		cpufreq_cooling_unregister(data->cool_dev);
 
 	return 0;
 }
-- 
1.8.2.1.342.gfa7285d

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[PATCH 03/16] drivers: thermal: cpu_cooling: introduce of_cpufreq_cooling_register

[Eduardo Valentin]

This patch introduces an API to register cpufreq cooling device
based on device tree node.

The registration via device tree node differs from normal
registration due to the fact that it is needed to fill
the device_node structure in order to be able to match
the cooling devices with trip points.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 drivers/thermal/Kconfig       |  1 +
 drivers/thermal/cpu_cooling.c | 31 +++++++++++++++++++++++++++++++
 include/linux/cpu_cooling.h   | 25 +++++++++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index dd81eb8..9e7cc3f 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -91,6 +91,7 @@ config THERMAL_GOV_USER_SPACE
 config CPU_THERMAL
 	bool "generic cpu cooling support"
 	depends on CPU_FREQ
+	depends on THERMAL_OF
 	select CPU_FREQ_TABLE
 	help
 	  This implements the generic cpu cooling mechanism through frequency
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index d179028..cd2f532 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -491,6 +491,37 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
 
 /**
+ * of_cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	struct thermal_cooling_device *cdev;
+
+	if (!np)
+		return ERR_PTR(-EINVAL);
+
+	cdev = cpufreq_cooling_register(clip_cpus);
+	if (IS_ERR(cdev))
+		return cdev;
+
+	cdev->np = np;
+
+	return cdev;
+}
+EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
+
+/**
  * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
  * @cdev: thermal cooling device pointer.
  *
diff --git a/include/linux/cpu_cooling.h b/include/linux/cpu_cooling.h
index a5d52ee..c303d38 100644
--- a/include/linux/cpu_cooling.h
+++ b/include/linux/cpu_cooling.h
@@ -24,6 +24,7 @@
 #ifndef __CPU_COOLING_H__
 #define __CPU_COOLING_H__
 
+#include <linux/of.h>
 #include <linux/thermal.h>
 #include <linux/cpumask.h>
 
@@ -36,6 +37,24 @@ struct thermal_cooling_device *
 cpufreq_cooling_register(const struct cpumask *clip_cpus);
 
 /**
+ * of_cpufreq_cooling_register - create cpufreq cooling device based on DT.
+ * @np: a valid struct device_node to the cooling device device tree node.
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen
+ */
+#ifdef CONFIG_THERMAL_OF
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus);
+#else
+static inline struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	return NULL;
+}
+#endif
+
+/**
  * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
  * @cdev: thermal cooling device pointer.
  */
@@ -48,6 +67,12 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 {
 	return NULL;
 }
+static inline struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	return NULL;
+}
 static inline
 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 {
-- 
1.8.2.1.342.gfa7285d

[PATCH 04/16] cpufreq: cpufreq-cpu0: add dt node parsing for cooling device properties

[Eduardo Valentin]

This patch changes the cpufreq-cpu0 driver to consider if
a cpu needs cooling (with cpufreq). In case the cooling is needed,
the cpu0 device tree node needs to be properly configured
with cooling device properties.

In case these properties are present,, the driver will
load a cpufreq cooling device in the system. The cpufreq-cpu0
driver is not interested in determining how the system should
be using the cooling device. The driver is responsible
only of loading the cooling device.

Describing how the cooling device will be used can be
accomplished by setting up a thermal zone that references
and is composed by the cpufreq cooling device.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 .../devicetree/bindings/cpufreq/cpufreq-cpu0.txt         |  7 +++++++
 drivers/cpufreq/Kconfig                                  |  2 +-
 drivers/cpufreq/cpufreq-cpu0.c                           | 16 ++++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
index 051f764..f055515 100644
--- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
@@ -15,6 +15,10 @@ Optional properties:
 - clock-latency: Specify the possible maximum transition latency for clock,
   in unit of nanoseconds.
 - voltage-tolerance: Specify the CPU voltage tolerance in percentage.
+- #cooling-cells:
+- cooling-min-level:
+- cooling-max-level:
+     Please refer to Documentation/devicetree/bindings/thermal/thermal.txt.
 
 Examples:
 
@@ -33,6 +37,9 @@ cpus {
 			198000  850000
 		>;
 		clock-latency = <61036>; /* two CLK32 periods */
+		#cooling-cells = <2>;
+		cooling-min-level = <0>;
+		cooling-max-level = <2>;
 	};
 
 	cpu@1 {
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 534fcb8..92e6921 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -186,7 +186,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
 
 config GENERIC_CPUFREQ_CPU0
 	tristate "Generic CPU0 cpufreq driver"
-	depends on HAVE_CLK && REGULATOR && PM_OPP && OF
+	depends on HAVE_CLK && REGULATOR && PM_OPP && OF && CPU_THERMAL
 	select CPU_FREQ_TABLE
 	help
 	  This adds a generic cpufreq driver for CPU0 frequency management.
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index cbfffa9..c573e95 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -12,7 +12,9 @@
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
+#include <linux/cpu_cooling.h>
 #include <linux/cpufreq.h>
+#include <linux/cpumask.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -20,6 +22,7 @@
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
+#include <linux/thermal.h>
 
 static unsigned int transition_latency;
 static unsigned int voltage_tolerance; /* in percentage */
@@ -28,6 +31,7 @@ static struct device *cpu_dev;
 static struct clk *cpu_clk;
 static struct regulator *cpu_reg;
 static struct cpufreq_frequency_table *freq_table;
+static struct thermal_cooling_device *cdev;
 
 static int cpu0_verify_speed(struct cpufreq_policy *policy)
 {
@@ -255,6 +259,17 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 		goto out_free_table;
 	}
 
+	/*
+	 * For now, just loading the cooling device;
+	 * thermal DT code takes care of matching them.
+	 */
+	if (of_find_property(np, "#cooling-cells", NULL)) {
+		cdev = of_cpufreq_cooling_register(np, cpu_present_mask);
+		if (IS_ERR(cdev))
+			pr_err("running cpufreq without cooling device: %ld\n",
+			       PTR_ERR(cdev));
+	}
+
 	of_node_put(np);
 	return 0;
 
@@ -267,6 +282,7 @@ out_put_node:
 
 static int cpu0_cpufreq_remove(struct platform_device *pdev)
 {
+	cpufreq_cooling_unregister(cdev);
 	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
 	opp_free_cpufreq_table(cpu_dev, &freq_table);
 
-- 
1.8.2.1.342.gfa7285d

[PATCH 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to lm75 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the lm75 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 drivers/hwmon/lm75.c | 46 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 5 deletions(-)

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index c03b490..2ba09ef 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -27,6 +27,8 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/thermal.h>
 #include "lm75.h"
 
 
@@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = {
 /* Each client has this additional data */
 struct lm75_data {
 	struct device		*hwmon_dev;
+	struct thermal_zone_device	*tz;
 	struct mutex		update_lock;
 	u8			orig_conf;
 	u8			resolution;	/* In bits, between 9 and 12 */
@@ -90,22 +93,42 @@ static struct lm75_data *lm75_update_device(struct device *dev);
 
 /*-----------------------------------------------------------------------*/
 
+static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
+{
+	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
+}
+
 /* sysfs attributes for hwmon */
 
+static int lm75_read_temp(void *dev, long *temp)
+{
+	struct lm75_data *data = lm75_update_device(dev);
+	long temperature;
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	temperature = lm75_reg_to_mc(data->temp[0], data->resolution);
+	if (temperature < 0)
+		dev_warn(data->hwmon_dev,
+			 "operating in negative temp: %ld\n", temperature);
+
+	*temp = temperature;
+
+	return 0;
+}
+
 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct lm75_data *data = lm75_update_device(dev);
-	long temp;
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-	temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)
-	       >> (data->resolution - 8);
-
-	return sprintf(buf, "%ld\n", temp);
+	return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
+						    data->resolution));
 }
 
 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -271,6 +294,17 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		goto exit_remove;
 	}
 
+	data->tz = thermal_zone_of_sensor_register(&client->dev,
+						   0,
+						   &client->dev,
+						   lm75_read_temp, NULL);
+	if (IS_ERR(data->tz)) {
+		dev_warn(&client->dev,
+			 "Could not parse thermal data in device tree: %ld\n",
+			 PTR_ERR(data->tz));
+		data->tz = NULL;
+	}
+
 	dev_info(&client->dev, "%s: sensor '%s'\n",
 		 dev_name(data->hwmon_dev), client->name);
 
@@ -285,6 +319,8 @@ static int lm75_remove(struct i2c_client *client)
 {
 	struct lm75_data *data = i2c_get_clientdata(client);
 
+	/* thermal zone life cycle is not our responsibility */
+	thermal_zone_of_sensor_unregister(&client->dev, data->tz);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &lm75_group);
 	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
-- 
1.8.2.1.342.gfa7285d

Re: [PATCH 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
> This patch adds to lm75 temperature sensor the possibility
> to expose itself as thermal zone device, registered on the
> thermal framework.
>
> The thermal zone is built only if a device tree node
> describing a thermal zone for this sensor is present
> inside the lm75 DT node. Otherwise, the driver behavior
> will be the same.
>
> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
> ---
>   drivers/hwmon/lm75.c | 46 +++++++++++++++++++++++++++++++++++++++++-----
>   1 file changed, 41 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
> index c03b490..2ba09ef 100644
> --- a/drivers/hwmon/lm75.c
> +++ b/drivers/hwmon/lm75.c
> @@ -27,6 +27,8 @@
>   #include <linux/hwmon-sysfs.h>
>   #include <linux/err.h>
>   #include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/thermal.h>
>   #include "lm75.h"
>
>
> @@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = {
>   /* Each client has this additional data */
>   struct lm75_data {
>   	struct device		*hwmon_dev;
> +	struct thermal_zone_device	*tz;
>   	struct mutex		update_lock;
>   	u8			orig_conf;
>   	u8			resolution;	/* In bits, between 9 and 12 */
> @@ -90,22 +93,42 @@ static struct lm75_data *lm75_update_device(struct device *dev);
>
>   /*-----------------------------------------------------------------------*/
>
> +static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
> +{
> +	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
> +}
> +
>   /* sysfs attributes for hwmon */
>
> +static int lm75_read_temp(void *dev, long *temp)
> +{
> +	struct lm75_data *data = lm75_update_device(dev);
> +	long temperature;
> +
> +	if (IS_ERR(data))
> +		return PTR_ERR(data);
> +
> +	temperature = lm75_reg_to_mc(data->temp[0], data->resolution);
> +	if (temperature < 0)
> +		dev_warn(data->hwmon_dev,
> +			 "operating in negative temp: %ld\n", temperature);

Please drop this warning. It is not the responsibility of the chip driver
to declare valid operational conditions, much less an arbitrary one
like zero degrees C.

Guenter

> +
> +	*temp = temperature;
> +
> +	return 0;
> +}
> +
>   static ssize_t show_temp(struct device *dev, struct device_attribute *da,
>   			 char *buf)
>   {
>   	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
>   	struct lm75_data *data = lm75_update_device(dev);
> -	long temp;
>
>   	if (IS_ERR(data))
>   		return PTR_ERR(data);
>
> -	temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)
> -	       >> (data->resolution - 8);
> -
> -	return sprintf(buf, "%ld\n", temp);
> +	return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
> +						    data->resolution));
>   }
>
>   static ssize_t set_temp(struct device *dev, struct device_attribute *da,
> @@ -271,6 +294,17 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
>   		goto exit_remove;
>   	}
>
> +	data->tz = thermal_zone_of_sensor_register(&client->dev,
> +						   0,
> +						   &client->dev,
> +						   lm75_read_temp, NULL);
> +	if (IS_ERR(data->tz)) {
> +		dev_warn(&client->dev,
> +			 "Could not parse thermal data in device tree: %ld\n",
> +			 PTR_ERR(data->tz));
> +		data->tz = NULL;
> +	}
> +
>   	dev_info(&client->dev, "%s: sensor '%s'\n",
>   		 dev_name(data->hwmon_dev), client->name);
>
> @@ -285,6 +319,8 @@ static int lm75_remove(struct i2c_client *client)
>   {
>   	struct lm75_data *data = i2c_get_clientdata(client);
>
> +	/* thermal zone life cycle is not our responsibility */
> +	thermal_zone_of_sensor_unregister(&client->dev, data->tz);
>   	hwmon_device_unregister(data->hwmon_dev);
>   	sysfs_remove_group(&client->dev.kobj, &lm75_group);
>   	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
>

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[PATCHv2 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to lm75 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the lm75 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
---
 drivers/hwmon/lm75.c | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

---

Guenter,

Here is a version without the warnings, as requested.

Eduardo

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index c03b490..e42e361 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -27,6 +27,8 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/thermal.h>
 #include "lm75.h"
 
 
@@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = {
 /* Each client has this additional data */
 struct lm75_data {
 	struct device		*hwmon_dev;
+	struct thermal_zone_device	*tz;
 	struct mutex		update_lock;
 	u8			orig_conf;
 	u8			resolution;	/* In bits, between 9 and 12 */
@@ -90,22 +93,36 @@ static struct lm75_data *lm75_update_device(struct device *dev);
 
 /*-----------------------------------------------------------------------*/
 
+static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
+{
+	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
+}
+
 /* sysfs attributes for hwmon */
 
+static int lm75_read_temp(void *dev, long *temp)
+{
+	struct lm75_data *data = lm75_update_device(dev);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	*temp = lm75_reg_to_mc(data->temp[0], data->resolution);
+
+	return 0;
+}
+
 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct lm75_data *data = lm75_update_device(dev);
-	long temp;
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-	temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)
-	       >> (data->resolution - 8);
-
-	return sprintf(buf, "%ld\n", temp);
+	return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
+						    data->resolution));
 }
 
 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -271,6 +288,13 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		goto exit_remove;
 	}
 
+	data->tz = thermal_zone_of_sensor_register(&client->dev,
+						   0,
+						   &client->dev,
+						   lm75_read_temp, NULL);
+	if (IS_ERR(data->tz))
+		data->tz = NULL;
+
 	dev_info(&client->dev, "%s: sensor '%s'\n",
 		 dev_name(data->hwmon_dev), client->name);
 
@@ -285,6 +309,8 @@ static int lm75_remove(struct i2c_client *client)
 {
 	struct lm75_data *data = i2c_get_clientdata(client);
 
+	/* thermal zone life cycle is not our responsibility */
+	thermal_zone_of_sensor_unregister(&client->dev, data->tz);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &lm75_group);
 	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
-- 
1.8.2.1.342.gfa7285d

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[PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to lm75 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the lm75 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 drivers/hwmon/lm75.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)
---
Hi Guenter,

Very minor change, removing comment, as requested.

Eduardo

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index c03b490..1d3600a 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -27,6 +27,8 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/thermal.h>
 #include "lm75.h"
 
 
@@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = {
 /* Each client has this additional data */
 struct lm75_data {
 	struct device		*hwmon_dev;
+	struct thermal_zone_device	*tz;
 	struct mutex		update_lock;
 	u8			orig_conf;
 	u8			resolution;	/* In bits, between 9 and 12 */
@@ -90,22 +93,36 @@ static struct lm75_data *lm75_update_device(struct device *dev);
 
 /*-----------------------------------------------------------------------*/
 
+static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
+{
+	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
+}
+
 /* sysfs attributes for hwmon */
 
+static int lm75_read_temp(void *dev, long *temp)
+{
+	struct lm75_data *data = lm75_update_device(dev);
+
+	if (IS_ERR(data))
+		return PTR_ERR(data);
+
+	*temp = lm75_reg_to_mc(data->temp[0], data->resolution);
+
+	return 0;
+}
+
 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 			 char *buf)
 {
 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 	struct lm75_data *data = lm75_update_device(dev);
-	long temp;
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
 
-	temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)
-	       >> (data->resolution - 8);
-
-	return sprintf(buf, "%ld\n", temp);
+	return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index],
+						    data->resolution));
 }
 
 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -271,6 +288,13 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		goto exit_remove;
 	}
 
+	data->tz = thermal_zone_of_sensor_register(&client->dev,
+						   0,
+						   &client->dev,
+						   lm75_read_temp, NULL);
+	if (IS_ERR(data->tz))
+		data->tz = NULL;
+
 	dev_info(&client->dev, "%s: sensor '%s'\n",
 		 dev_name(data->hwmon_dev), client->name);
 
@@ -285,6 +309,7 @@ static int lm75_remove(struct i2c_client *client)
 {
 	struct lm75_data *data = i2c_get_clientdata(client);
 
+	thermal_zone_of_sensor_unregister(&client->dev, data->tz);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &lm75_group);
 	lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
-- 
1.8.2.1.342.gfa7285d

Re: [PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/18/2013 09:21 AM, Eduardo Valentin wrote:
> This patch adds to lm75 temperature sensor the possibility
> to expose itself as thermal zone device, registered on the
> thermal framework.
>
> The thermal zone is built only if a device tree node
> describing a thermal zone for this sensor is present
> inside the lm75 DT node. Otherwise, the driver behavior
> will be the same.
>
> Cc: Jean Delvare <khali@linux-fr.org>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: lm-sensors@lm-sensors.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>

Acked-by: Guenter Roeck <linux@roeck-us.net>

I assume this will be sent upstream through the thermal tree ?

Guenter

Re: [PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 1172 bytes --]

On 21-09-2013 14:06, Guenter Roeck wrote:
> On 09/18/2013 09:21 AM, Eduardo Valentin wrote:
>> This patch adds to lm75 temperature sensor the possibility
>> to expose itself as thermal zone device, registered on the
>> thermal framework.
>>
>> The thermal zone is built only if a device tree node
>> describing a thermal zone for this sensor is present
>> inside the lm75 DT node. Otherwise, the driver behavior
>> will be the same.
>>
>> Cc: Jean Delvare <khali@linux-fr.org>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: lm-sensors@lm-sensors.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
> 
> Acked-by: Guenter Roeck <linux@roeck-us.net>
> 

Cool! thanks again for taking the time to review this.

> I assume this will be sent upstream through the thermal tree ?

Yeah, that is the idea, at least for the core part. The hwmon changes I
believe goes via hwmon tree, right?


I still need acks from device tree maintainers before moving forward,
though.


> 
> Guenter
> 
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/21/2013 04:30 PM, Eduardo Valentin wrote:
> On 21-09-2013 14:06, Guenter Roeck wrote:
>> On 09/18/2013 09:21 AM, Eduardo Valentin wrote:
>>> This patch adds to lm75 temperature sensor the possibility
>>> to expose itself as thermal zone device, registered on the
>>> thermal framework.
>>>
>>> The thermal zone is built only if a device tree node
>>> describing a thermal zone for this sensor is present
>>> inside the lm75 DT node. Otherwise, the driver behavior
>>> will be the same.
>>>
>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
>>> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>>> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
>>> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>>
>> Acked-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>>
>
> Cool! thanks again for taking the time to review this.
>
>> I assume this will be sent upstream through the thermal tree ?
>
> Yeah, that is the idea, at least for the core part. The hwmon changes I
> believe goes via hwmon tree, right?
>

Not necessarily, as the hwmon code depends on the core code.
In such cases it is quite common that both are sent through the same tree.

Guenter

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Re: [PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 1457 bytes --]

On 21-09-2013 19:56, Guenter Roeck wrote:
> On 09/21/2013 04:30 PM, Eduardo Valentin wrote:
>> On 21-09-2013 14:06, Guenter Roeck wrote:
>>> On 09/18/2013 09:21 AM, Eduardo Valentin wrote:
>>>> This patch adds to lm75 temperature sensor the possibility
>>>> to expose itself as thermal zone device, registered on the
>>>> thermal framework.
>>>>
>>>> The thermal zone is built only if a device tree node
>>>> describing a thermal zone for this sensor is present
>>>> inside the lm75 DT node. Otherwise, the driver behavior
>>>> will be the same.
>>>>
>>>> Cc: Jean Delvare <khali@linux-fr.org>
>>>> Cc: Guenter Roeck <linux@roeck-us.net>
>>>> Cc: lm-sensors@lm-sensors.org
>>>> Cc: linux-kernel@vger.kernel.org
>>>> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
>>>
>>> Acked-by: Guenter Roeck <linux@roeck-us.net>
>>>
>>
>> Cool! thanks again for taking the time to review this.
>>
>>> I assume this will be sent upstream through the thermal tree ?
>>
>> Yeah, that is the idea, at least for the core part. The hwmon changes I
>> believe goes via hwmon tree, right?
>>
> 
> Not necessarily, as the hwmon code depends on the core code.
> In such cases it is quite common that both are sent through the same tree.

If this works for you I can queue these changes via the thermal tree.

> 
> Guenter
> 
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCHv3 05/16] hwmon: lm75: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/21/2013 05:23 PM, Eduardo Valentin wrote:
> On 21-09-2013 19:56, Guenter Roeck wrote:
>> On 09/21/2013 04:30 PM, Eduardo Valentin wrote:
>>> On 21-09-2013 14:06, Guenter Roeck wrote:
>>>> On 09/18/2013 09:21 AM, Eduardo Valentin wrote:
>>>>> This patch adds to lm75 temperature sensor the possibility
>>>>> to expose itself as thermal zone device, registered on the
>>>>> thermal framework.
>>>>>
>>>>> The thermal zone is built only if a device tree node
>>>>> describing a thermal zone for this sensor is present
>>>>> inside the lm75 DT node. Otherwise, the driver behavior
>>>>> will be the same.
>>>>>
>>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
>>>>> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>>>>> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
>>>>> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>>>>> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>>>>
>>>> Acked-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>>>>
>>>
>>> Cool! thanks again for taking the time to review this.
>>>
>>>> I assume this will be sent upstream through the thermal tree ?
>>>
>>> Yeah, that is the idea, at least for the core part. The hwmon changes I
>>> believe goes via hwmon tree, right?
>>>
>>
>> Not necessarily, as the hwmon code depends on the core code.
>> In such cases it is quite common that both are sent through the same tree.
>
> If this works for you I can queue these changes via the thermal tree.
>

Ok with me.

Guenter


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[PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to tmp102 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the tmp102 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 drivers/hwmon/tmp102.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index d7b47ab..e432444 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -27,6 +27,8 @@
 #include <linux/mutex.h>
 #include <linux/device.h>
 #include <linux/jiffies.h>
+#include <linux/thermal.h>
+#include <linux/of.h>
 
 #define	DRIVER_NAME "tmp102"
 
@@ -50,6 +52,7 @@
 
 struct tmp102 {
 	struct device *hwmon_dev;
+	struct thermal_zone_device *tz;
 	struct mutex lock;
 	u16 config_orig;
 	unsigned long last_update;
@@ -93,6 +96,19 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
 	return tmp102;
 }
 
+static int tmp102_read_temp(void *dev, long *temp)
+{
+	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
+
+	if (tmp102->temp[0] < 0)
+		dev_warn(tmp102->hwmon_dev,
+			 "operating in negative temp: %d\n", tmp102->temp[0]);
+
+	*temp = tmp102->temp[0];
+
+	return 0;
+}
+
 static ssize_t tmp102_show_temp(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
@@ -204,6 +220,16 @@ static int tmp102_probe(struct i2c_client *client,
 		goto fail_remove_sysfs;
 	}
 
+	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
+						     &client->dev,
+						     tmp102_read_temp, NULL);
+	if (IS_ERR(tmp102->tz)) {
+		dev_warn(&client->dev,
+			 "Could not parse thermal data in device tree: %ld\n",
+			 PTR_ERR(tmp102->tz));
+		tmp102->tz = NULL;
+	}
+
 	dev_info(&client->dev, "initialized\n");
 
 	return 0;
@@ -220,6 +246,8 @@ static int tmp102_remove(struct i2c_client *client)
 {
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);
 
+	/* thermal zone life cycle is not our responsibility */
+	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
 	hwmon_device_unregister(tmp102->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
 
-- 
1.8.2.1.342.gfa7285d

Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
> This patch adds to tmp102 temperature sensor the possibility
> to expose itself as thermal zone device, registered on the
> thermal framework.
>
> The thermal zone is built only if a device tree node
> describing a thermal zone for this sensor is present
> inside the tmp102 DT node. Otherwise, the driver behavior
> will be the same.
>
> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
> ---
>   drivers/hwmon/tmp102.c | 28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
>
> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
> index d7b47ab..e432444 100644
> --- a/drivers/hwmon/tmp102.c
> +++ b/drivers/hwmon/tmp102.c
> @@ -27,6 +27,8 @@
>   #include <linux/mutex.h>
>   #include <linux/device.h>
>   #include <linux/jiffies.h>
> +#include <linux/thermal.h>
> +#include <linux/of.h>
>
>   #define	DRIVER_NAME "tmp102"
>
> @@ -50,6 +52,7 @@
>
>   struct tmp102 {
>   	struct device *hwmon_dev;
> +	struct thermal_zone_device *tz;
>   	struct mutex lock;
>   	u16 config_orig;
>   	unsigned long last_update;
> @@ -93,6 +96,19 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
>   	return tmp102;
>   }
>
> +static int tmp102_read_temp(void *dev, long *temp)
> +{
> +	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
> +
> +	if (tmp102->temp[0] < 0)
> +		dev_warn(tmp102->hwmon_dev,
> +			 "operating in negative temp: %d\n", tmp102->temp[0]);
> +

Please drop this warning.

Guenter

> +	*temp = tmp102->temp[0];
> +
> +	return 0;
> +}
> +
>   static ssize_t tmp102_show_temp(struct device *dev,
>   				struct device_attribute *attr,
>   				char *buf)
> @@ -204,6 +220,16 @@ static int tmp102_probe(struct i2c_client *client,
>   		goto fail_remove_sysfs;
>   	}
>
> +	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
> +						     &client->dev,
> +						     tmp102_read_temp, NULL);
> +	if (IS_ERR(tmp102->tz)) {
> +		dev_warn(&client->dev,
> +			 "Could not parse thermal data in device tree: %ld\n",
> +			 PTR_ERR(tmp102->tz));

Please drop this warning. You already create error messages in
thermal_zone_of_sensor_register(). That should be sufficient.
The same applies to the lm75 patch.

As a side note, I would suggest to provide devm_ functions for registration.
We are introducing those for hwmon registration, which enables us to remove
most _remove functions. It would be great if we can keep it that way.

On a higher level, I don't think it is a good idea to make thermal zones
and thermal zone data mandatory. Many systems may neither need nor want it.

Guenter

> +		tmp102->tz = NULL;
> +	}
> +
>   	dev_info(&client->dev, "initialized\n");
>
>   	return 0;
> @@ -220,6 +246,8 @@ static int tmp102_remove(struct i2c_client *client)
>   {
>   	struct tmp102 *tmp102 = i2c_get_clientdata(client);
>
> +	/* thermal zone life cycle is not our responsibility */
> +	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
>   	hwmon_device_unregister(tmp102->hwmon_dev);
>   	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
>
>

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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 4499 bytes --]

On 15-09-2013 19:33, Guenter Roeck wrote:
> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
>> This patch adds to tmp102 temperature sensor the possibility
>> to expose itself as thermal zone device, registered on the
>> thermal framework.
>>
>> The thermal zone is built only if a device tree node
>> describing a thermal zone for this sensor is present
>> inside the tmp102 DT node. Otherwise, the driver behavior
>> will be the same.
>>
>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
>> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
>> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>> ---
>>   drivers/hwmon/tmp102.c | 28 ++++++++++++++++++++++++++++
>>   1 file changed, 28 insertions(+)
>>
>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
>> index d7b47ab..e432444 100644
>> --- a/drivers/hwmon/tmp102.c
>> +++ b/drivers/hwmon/tmp102.c
>> @@ -27,6 +27,8 @@
>>   #include <linux/mutex.h>
>>   #include <linux/device.h>
>>   #include <linux/jiffies.h>
>> +#include <linux/thermal.h>
>> +#include <linux/of.h>
>>
>>   #define    DRIVER_NAME "tmp102"
>>
>> @@ -50,6 +52,7 @@
>>
>>   struct tmp102 {
>>       struct device *hwmon_dev;
>> +    struct thermal_zone_device *tz;
>>       struct mutex lock;
>>       u16 config_orig;
>>       unsigned long last_update;
>> @@ -93,6 +96,19 @@ static struct tmp102 *tmp102_update_device(struct
>> i2c_client *client)
>>       return tmp102;
>>   }
>>
>> +static int tmp102_read_temp(void *dev, long *temp)
>> +{
>> +    struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
>> +
>> +    if (tmp102->temp[0] < 0)
>> +        dev_warn(tmp102->hwmon_dev,
>> +             "operating in negative temp: %d\n", tmp102->temp[0]);
>> +
> 
> Please drop this warning.
> 

Done for both drivers.

> Guenter
> 
>> +    *temp = tmp102->temp[0];
>> +
>> +    return 0;
>> +}
>> +
>>   static ssize_t tmp102_show_temp(struct device *dev,
>>                   struct device_attribute *attr,
>>                   char *buf)
>> @@ -204,6 +220,16 @@ static int tmp102_probe(struct i2c_client *client,
>>           goto fail_remove_sysfs;
>>       }
>>
>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
>> +                             &client->dev,
>> +                             tmp102_read_temp, NULL);
>> +    if (IS_ERR(tmp102->tz)) {
>> +        dev_warn(&client->dev,
>> +             "Could not parse thermal data in device tree: %ld\n",
>> +             PTR_ERR(tmp102->tz));
> 
> Please drop this warning. You already create error messages in
> thermal_zone_of_sensor_register(). That should be sufficient.
> The same applies to the lm75 patch.

OK. Done for both.

> 
> As a side note, I would suggest to provide devm_ functions for
> registration.
> We are introducing those for hwmon registration, which enables us to remove
> most _remove functions. It would be great if we can keep it that way.
> 

Right. This side note is taken. Actually this is on my todo list for
quite a while. But I believe this should not block this series, should
it? I will be probably cleaning the thermal framework code after this
current work is accepted at least.

> On a higher level, I don't think it is a good idea to make thermal zones
> and thermal zone data mandatory. Many systems may neither need nor want it.
> 

Well, I agree with you. Did you see something hard required in the patch
I sent. I made it so that it could continue the driver probe without
thermal zones, as you requested.


I will repost both patches in reply to our thread.

Eduardo

> Guenter
> 
>> +        tmp102->tz = NULL;
>> +    }
>> +
>>       dev_info(&client->dev, "initialized\n");
>>
>>       return 0;
>> @@ -220,6 +246,8 @@ static int tmp102_remove(struct i2c_client *client)
>>   {
>>       struct tmp102 *tmp102 = i2c_get_clientdata(client);
>>
>> +    /* thermal zone life cycle is not our responsibility */
>> +    thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
>>       hwmon_device_unregister(tmp102->hwmon_dev);
>>       sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
>>
>>
> 
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 5929 bytes --]

On 18-09-2013 07:18, Guenter Roeck wrote:
> On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
>> On 15-09-2013 19:33, Guenter Roeck wrote:
>>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
>>>> This patch adds to tmp102 temperature sensor the possibility to
>>>> expose itself as thermal zone device, registered on the thermal
>>>> framework.
>>>> 
>>>> The thermal zone is built only if a device tree node describing
>>>> a thermal zone for this sensor is present inside the tmp102 DT
>>>> node. Otherwise, the driver behavior will be the same.
>>>> 
>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
>>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
>>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
>>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
>>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
>>>> 
>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
>>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
>>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
>>>> <linux/mutex.h> #include <linux/device.h> #include
>>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
>>>> <linux/of.h>
>>>> 
>>>> #define    DRIVER_NAME "tmp102"
>>>> 
>>>> @@ -50,6 +52,7 @@
>>>> 
>>>> struct tmp102 { struct device *hwmon_dev; +    struct
>>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
>>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
>>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
>>>> tmp102; }
>>>> 
>>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
>>>> struct tmp102 *tmp102 =
>>>> tmp102_update_device(to_i2c_client(dev)); + +    if
>>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
>>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
>>> 
>>> Please drop this warning.
>>> 
>> 
>> Done for both drivers.
>> 
>>> Guenter
>>> 
>>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
>>>> ssize_t tmp102_show_temp(struct device *dev, struct
>>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
>>>> int tmp102_probe(struct i2c_client *client, goto
>>>> fail_remove_sysfs; }
>>>> 
>>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
>>>> 0, +                             &client->dev, +
>>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
>>>> dev_warn(&client->dev, +             "Could not parse thermal
>>>> data in device tree: %ld\n", +
>>>> PTR_ERR(tmp102->tz));
>>> 
>>> Please drop this warning. You already create error messages in 
>>> thermal_zone_of_sensor_register(). That should be sufficient. The
>>> same applies to the lm75 patch.
>> 
>> OK. Done for both.
>> 
>>> 
>>> As a side note, I would suggest to provide devm_ functions for 
>>> registration. We are introducing those for hwmon registration,
>>> which enables us to remove most _remove functions. It would be
>>> great if we can keep it that way.
>>> 
>> 
>> Right. This side note is taken. Actually this is on my todo list
>> for quite a while. But I believe this should not block this series,
>> should it? I will be probably cleaning the thermal framework code
>> after this current work is accepted at least.
>> 
>>> On a higher level, I don't think it is a good idea to make
>>> thermal zones and thermal zone data mandatory. Many systems may
>>> neither need nor want it.
>>> 
>> 
>> Well, I agree with you. Did you see something hard required in the
>> patch I sent. I made it so that it could continue the driver probe
>> without thermal zones, as you requested.
>> 
> If it is not mandatory you should not dump an error message to the
> console in the thermal registration function. Since you do, you at
> least consider it mandatory if that function is called.
> 
> So please either drop the error message from the registration
> function or add a check into the drivers to only register into the
> thermal subsystem if there is a respective thermal entry for that
> sensor in the devicetree data.
> 
> There are systes out there with literally dozens of temperature
> sensors. In many cases, those are purely for system health
> monitoring, not for thermal management. I don't want to end up in a
> situation where users complain about dozens of error messages on the
> console and no way to avoid it but providing dummy thermal subsystem
> data.
> 

Now I see.


Then I will rollback to the previous version in which lm sensors were
first probing for thermal properties within their dt node. Something like:
diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index dc96598..cb1c663 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
                goto fail_remove_sysfs;
        }

-       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
-                                                    &client->dev,
-                                                    tmp102_read_temp,
NULL);
-       if (IS_ERR(tmp102->tz))
-               tmp102->tz = NULL;
+       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
+               tmp102->tz =
thermal_zone_of_sensor_register(&client->dev, 0,
+                                                            &client->dev,
+
tmp102_read_temp, NULL);
+               if (IS_ERR(tmp102->tz))
+                       tmp102->tz = NULL;
+       }

        dev_info(&client->dev, "initialized\n");


Does it sound reasonable?


> Guenter
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On Wed, Sep 18, 2013 at 10:29:09AM -0400, Eduardo Valentin wrote:
> On 18-09-2013 07:18, Guenter Roeck wrote:
> > On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
> >> On 15-09-2013 19:33, Guenter Roeck wrote:
> >>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
> >>>> This patch adds to tmp102 temperature sensor the possibility to
> >>>> expose itself as thermal zone device, registered on the thermal
> >>>> framework.
> >>>> 
> >>>> The thermal zone is built only if a device tree node describing
> >>>> a thermal zone for this sensor is present inside the tmp102 DT
> >>>> node. Otherwise, the driver behavior will be the same.
> >>>> 
> >>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
> >>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
> >>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
> >>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
> >>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
> >>>> 
> >>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
> >>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
> >>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
> >>>> <linux/mutex.h> #include <linux/device.h> #include
> >>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
> >>>> <linux/of.h>
> >>>> 
> >>>> #define    DRIVER_NAME "tmp102"
> >>>> 
> >>>> @@ -50,6 +52,7 @@
> >>>> 
> >>>> struct tmp102 { struct device *hwmon_dev; +    struct
> >>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
> >>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
> >>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
> >>>> tmp102; }
> >>>> 
> >>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
> >>>> struct tmp102 *tmp102 =
> >>>> tmp102_update_device(to_i2c_client(dev)); + +    if
> >>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
> >>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
> >>> 
> >>> Please drop this warning.
> >>> 
> >> 
> >> Done for both drivers.
> >> 
> >>> Guenter
> >>> 
> >>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
> >>>> ssize_t tmp102_show_temp(struct device *dev, struct
> >>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
> >>>> int tmp102_probe(struct i2c_client *client, goto
> >>>> fail_remove_sysfs; }
> >>>> 
> >>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
> >>>> 0, +                             &client->dev, +
> >>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
> >>>> dev_warn(&client->dev, +             "Could not parse thermal
> >>>> data in device tree: %ld\n", +
> >>>> PTR_ERR(tmp102->tz));
> >>> 
> >>> Please drop this warning. You already create error messages in 
> >>> thermal_zone_of_sensor_register(). That should be sufficient. The
> >>> same applies to the lm75 patch.
> >> 
> >> OK. Done for both.
> >> 
> >>> 
> >>> As a side note, I would suggest to provide devm_ functions for 
> >>> registration. We are introducing those for hwmon registration,
> >>> which enables us to remove most _remove functions. It would be
> >>> great if we can keep it that way.
> >>> 
> >> 
> >> Right. This side note is taken. Actually this is on my todo list
> >> for quite a while. But I believe this should not block this series,
> >> should it? I will be probably cleaning the thermal framework code
> >> after this current work is accepted at least.
> >> 
> >>> On a higher level, I don't think it is a good idea to make
> >>> thermal zones and thermal zone data mandatory. Many systems may
> >>> neither need nor want it.
> >>> 
> >> 
> >> Well, I agree with you. Did you see something hard required in the
> >> patch I sent. I made it so that it could continue the driver probe
> >> without thermal zones, as you requested.
> >> 
> > If it is not mandatory you should not dump an error message to the
> > console in the thermal registration function. Since you do, you at
> > least consider it mandatory if that function is called.
> > 
> > So please either drop the error message from the registration
> > function or add a check into the drivers to only register into the
> > thermal subsystem if there is a respective thermal entry for that
> > sensor in the devicetree data.
> > 
> > There are systes out there with literally dozens of temperature
> > sensors. In many cases, those are purely for system health
> > monitoring, not for thermal management. I don't want to end up in a
> > situation where users complain about dozens of error messages on the
> > console and no way to avoid it but providing dummy thermal subsystem
> > data.
> > 
> 
> Now I see.
> 
> 
> Then I will rollback to the previous version in which lm sensors were
> first probing for thermal properties within their dt node. Something like:
> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
> index dc96598..cb1c663 100644
> --- a/drivers/hwmon/tmp102.c
> +++ b/drivers/hwmon/tmp102.c
> @@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
>                 goto fail_remove_sysfs;
>         }
> 
> -       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
> -                                                    &client->dev,
> -                                                    tmp102_read_temp,
> NULL);
> -       if (IS_ERR(tmp102->tz))
> -               tmp102->tz = NULL;
> +       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
> +               tmp102->tz =
> thermal_zone_of_sensor_register(&client->dev, 0,
> +                                                            &client->dev,
> +
> tmp102_read_temp, NULL);
> +               if (IS_ERR(tmp102->tz))
> +                       tmp102->tz = NULL;
> +       }
> 
>         dev_info(&client->dev, "initialized\n");
> 
> 
> Does it sound reasonable?
> 
Personally I would prefer if the registration code fails silently.
Pushing the above code into each driver is just adding the same code
repeatedly all over the place.

Also, each sensor instance will still result in an error if there
is no global "thermal-zones" entry. Checking for that global entry
in each driver would be even more excessive, and I just don't like
that noisyness.

Also, I think you'll need to create devicetree bindings documents
for the two sensors.

Guenter
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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 7166 bytes --]

On 18-09-2013 11:17, Guenter Roeck wrote:
> On Wed, Sep 18, 2013 at 10:29:09AM -0400, Eduardo Valentin wrote:
>> On 18-09-2013 07:18, Guenter Roeck wrote:
>>> On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
>>>> On 15-09-2013 19:33, Guenter Roeck wrote:
>>>>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
>>>>>> This patch adds to tmp102 temperature sensor the possibility to
>>>>>> expose itself as thermal zone device, registered on the thermal
>>>>>> framework.
>>>>>>
>>>>>> The thermal zone is built only if a device tree node describing
>>>>>> a thermal zone for this sensor is present inside the tmp102 DT
>>>>>> node. Otherwise, the driver behavior will be the same.
>>>>>>
>>>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
>>>>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
>>>>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
>>>>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
>>>>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
>>>>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
>>>>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
>>>>>> <linux/mutex.h> #include <linux/device.h> #include
>>>>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
>>>>>> <linux/of.h>
>>>>>>
>>>>>> #define    DRIVER_NAME "tmp102"
>>>>>>
>>>>>> @@ -50,6 +52,7 @@
>>>>>>
>>>>>> struct tmp102 { struct device *hwmon_dev; +    struct
>>>>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
>>>>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
>>>>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
>>>>>> tmp102; }
>>>>>>
>>>>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
>>>>>> struct tmp102 *tmp102 =
>>>>>> tmp102_update_device(to_i2c_client(dev)); + +    if
>>>>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
>>>>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
>>>>>
>>>>> Please drop this warning.
>>>>>
>>>>
>>>> Done for both drivers.
>>>>
>>>>> Guenter
>>>>>
>>>>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
>>>>>> ssize_t tmp102_show_temp(struct device *dev, struct
>>>>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
>>>>>> int tmp102_probe(struct i2c_client *client, goto
>>>>>> fail_remove_sysfs; }
>>>>>>
>>>>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
>>>>>> 0, +                             &client->dev, +
>>>>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
>>>>>> dev_warn(&client->dev, +             "Could not parse thermal
>>>>>> data in device tree: %ld\n", +
>>>>>> PTR_ERR(tmp102->tz));
>>>>>
>>>>> Please drop this warning. You already create error messages in 
>>>>> thermal_zone_of_sensor_register(). That should be sufficient. The
>>>>> same applies to the lm75 patch.
>>>>
>>>> OK. Done for both.
>>>>
>>>>>
>>>>> As a side note, I would suggest to provide devm_ functions for 
>>>>> registration. We are introducing those for hwmon registration,
>>>>> which enables us to remove most _remove functions. It would be
>>>>> great if we can keep it that way.
>>>>>
>>>>
>>>> Right. This side note is taken. Actually this is on my todo list
>>>> for quite a while. But I believe this should not block this series,
>>>> should it? I will be probably cleaning the thermal framework code
>>>> after this current work is accepted at least.
>>>>
>>>>> On a higher level, I don't think it is a good idea to make
>>>>> thermal zones and thermal zone data mandatory. Many systems may
>>>>> neither need nor want it.
>>>>>
>>>>
>>>> Well, I agree with you. Did you see something hard required in the
>>>> patch I sent. I made it so that it could continue the driver probe
>>>> without thermal zones, as you requested.
>>>>
>>> If it is not mandatory you should not dump an error message to the
>>> console in the thermal registration function. Since you do, you at
>>> least consider it mandatory if that function is called.
>>>
>>> So please either drop the error message from the registration
>>> function or add a check into the drivers to only register into the
>>> thermal subsystem if there is a respective thermal entry for that
>>> sensor in the devicetree data.
>>>
>>> There are systes out there with literally dozens of temperature
>>> sensors. In many cases, those are purely for system health
>>> monitoring, not for thermal management. I don't want to end up in a
>>> situation where users complain about dozens of error messages on the
>>> console and no way to avoid it but providing dummy thermal subsystem
>>> data.
>>>
>>
>> Now I see.
>>
>>
>> Then I will rollback to the previous version in which lm sensors were
>> first probing for thermal properties within their dt node. Something like:
>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
>> index dc96598..cb1c663 100644
>> --- a/drivers/hwmon/tmp102.c
>> +++ b/drivers/hwmon/tmp102.c
>> @@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
>>                 goto fail_remove_sysfs;
>>         }
>>
>> -       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
>> -                                                    &client->dev,
>> -                                                    tmp102_read_temp,
>> NULL);
>> -       if (IS_ERR(tmp102->tz))
>> -               tmp102->tz = NULL;
>> +       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
>> +               tmp102->tz =
>> thermal_zone_of_sensor_register(&client->dev, 0,
>> +                                                            &client->dev,
>> +
>> tmp102_read_temp, NULL);
>> +               if (IS_ERR(tmp102->tz))
>> +                       tmp102->tz = NULL;
>> +       }
>>
>>         dev_info(&client->dev, "initialized\n");
>>
>>
>> Does it sound reasonable?
>>
> Personally I would prefer if the registration code fails silently.
> Pushing the above code into each driver is just adding the same code
> repeatedly all over the place.

Fair enough. It becomes tedious and just duplicating code. I agree.

So I will keep the v2 I just sent and remove the annoying error messages
from of-thermal.c while registering the sensors.

> 
> Also, each sensor instance will still result in an error if there
> is no global "thermal-zones" entry. Checking for that global entry
> in each driver would be even more excessive, and I just don't like
> that noisyness.
> 
> Also, I think you'll need to create devicetree bindings documents
> for the two sensors.
> 

Why would I? There is only one extra property and that is already
documented. I think the sensor still falls into the dummy dt node.

> Guenter
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On Wed, Sep 18, 2013 at 11:54:18AM -0400, Eduardo Valentin wrote:
> On 18-09-2013 11:17, Guenter Roeck wrote:
> > On Wed, Sep 18, 2013 at 10:29:09AM -0400, Eduardo Valentin wrote:
> >> On 18-09-2013 07:18, Guenter Roeck wrote:
> >>> On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
> >>>> On 15-09-2013 19:33, Guenter Roeck wrote:
> >>>>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
> >>>>>> This patch adds to tmp102 temperature sensor the possibility to
> >>>>>> expose itself as thermal zone device, registered on the thermal
> >>>>>> framework.
> >>>>>>
> >>>>>> The thermal zone is built only if a device tree node describing
> >>>>>> a thermal zone for this sensor is present inside the tmp102 DT
> >>>>>> node. Otherwise, the driver behavior will be the same.
> >>>>>>
> >>>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
> >>>>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
> >>>>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
> >>>>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
> >>>>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
> >>>>>>
> >>>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
> >>>>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
> >>>>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
> >>>>>> <linux/mutex.h> #include <linux/device.h> #include
> >>>>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
> >>>>>> <linux/of.h>
> >>>>>>
> >>>>>> #define    DRIVER_NAME "tmp102"
> >>>>>>
> >>>>>> @@ -50,6 +52,7 @@
> >>>>>>
> >>>>>> struct tmp102 { struct device *hwmon_dev; +    struct
> >>>>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
> >>>>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
> >>>>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
> >>>>>> tmp102; }
> >>>>>>
> >>>>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
> >>>>>> struct tmp102 *tmp102 =
> >>>>>> tmp102_update_device(to_i2c_client(dev)); + +    if
> >>>>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
> >>>>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
> >>>>>
> >>>>> Please drop this warning.
> >>>>>
> >>>>
> >>>> Done for both drivers.
> >>>>
> >>>>> Guenter
> >>>>>
> >>>>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
> >>>>>> ssize_t tmp102_show_temp(struct device *dev, struct
> >>>>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
> >>>>>> int tmp102_probe(struct i2c_client *client, goto
> >>>>>> fail_remove_sysfs; }
> >>>>>>
> >>>>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
> >>>>>> 0, +                             &client->dev, +
> >>>>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
> >>>>>> dev_warn(&client->dev, +             "Could not parse thermal
> >>>>>> data in device tree: %ld\n", +
> >>>>>> PTR_ERR(tmp102->tz));
> >>>>>
> >>>>> Please drop this warning. You already create error messages in 
> >>>>> thermal_zone_of_sensor_register(). That should be sufficient. The
> >>>>> same applies to the lm75 patch.
> >>>>
> >>>> OK. Done for both.
> >>>>
> >>>>>
> >>>>> As a side note, I would suggest to provide devm_ functions for 
> >>>>> registration. We are introducing those for hwmon registration,
> >>>>> which enables us to remove most _remove functions. It would be
> >>>>> great if we can keep it that way.
> >>>>>
> >>>>
> >>>> Right. This side note is taken. Actually this is on my todo list
> >>>> for quite a while. But I believe this should not block this series,
> >>>> should it? I will be probably cleaning the thermal framework code
> >>>> after this current work is accepted at least.
> >>>>
> >>>>> On a higher level, I don't think it is a good idea to make
> >>>>> thermal zones and thermal zone data mandatory. Many systems may
> >>>>> neither need nor want it.
> >>>>>
> >>>>
> >>>> Well, I agree with you. Did you see something hard required in the
> >>>> patch I sent. I made it so that it could continue the driver probe
> >>>> without thermal zones, as you requested.
> >>>>
> >>> If it is not mandatory you should not dump an error message to the
> >>> console in the thermal registration function. Since you do, you at
> >>> least consider it mandatory if that function is called.
> >>>
> >>> So please either drop the error message from the registration
> >>> function or add a check into the drivers to only register into the
> >>> thermal subsystem if there is a respective thermal entry for that
> >>> sensor in the devicetree data.
> >>>
> >>> There are systes out there with literally dozens of temperature
> >>> sensors. In many cases, those are purely for system health
> >>> monitoring, not for thermal management. I don't want to end up in a
> >>> situation where users complain about dozens of error messages on the
> >>> console and no way to avoid it but providing dummy thermal subsystem
> >>> data.
> >>>
> >>
> >> Now I see.
> >>
> >>
> >> Then I will rollback to the previous version in which lm sensors were
> >> first probing for thermal properties within their dt node. Something like:
> >> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
> >> index dc96598..cb1c663 100644
> >> --- a/drivers/hwmon/tmp102.c
> >> +++ b/drivers/hwmon/tmp102.c
> >> @@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
> >>                 goto fail_remove_sysfs;
> >>         }
> >>
> >> -       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
> >> -                                                    &client->dev,
> >> -                                                    tmp102_read_temp,
> >> NULL);
> >> -       if (IS_ERR(tmp102->tz))
> >> -               tmp102->tz = NULL;
> >> +       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
> >> +               tmp102->tz =
> >> thermal_zone_of_sensor_register(&client->dev, 0,
> >> +                                                            &client->dev,
> >> +
> >> tmp102_read_temp, NULL);
> >> +               if (IS_ERR(tmp102->tz))
> >> +                       tmp102->tz = NULL;
> >> +       }
> >>
> >>         dev_info(&client->dev, "initialized\n");
> >>
> >>
> >> Does it sound reasonable?
> >>
> > Personally I would prefer if the registration code fails silently.
> > Pushing the above code into each driver is just adding the same code
> > repeatedly all over the place.
> 
> Fair enough. It becomes tedious and just duplicating code. I agree.
> 
> So I will keep the v2 I just sent and remove the annoying error messages
> from of-thermal.c while registering the sensors.
> 
> > 
> > Also, each sensor instance will still result in an error if there
> > is no global "thermal-zones" entry. Checking for that global entry
> > in each driver would be even more excessive, and I just don't like
> > that noisyness.
> > 
> > Also, I think you'll need to create devicetree bindings documents
> > for the two sensors.
> > 
> 
> Why would I? There is only one extra property and that is already
> documented. I think the sensor still falls into the dummy dt node.
> 
I'll leave that up to the devicetree folks to decide.

Guenter
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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 7813 bytes --]

On 18-09-2013 11:57, Guenter Roeck wrote:
> On Wed, Sep 18, 2013 at 11:54:18AM -0400, Eduardo Valentin wrote:
>> On 18-09-2013 11:17, Guenter Roeck wrote:
>>> On Wed, Sep 18, 2013 at 10:29:09AM -0400, Eduardo Valentin wrote:
>>>> On 18-09-2013 07:18, Guenter Roeck wrote:
>>>>> On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
>>>>>> On 15-09-2013 19:33, Guenter Roeck wrote:
>>>>>>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
>>>>>>>> This patch adds to tmp102 temperature sensor the possibility to
>>>>>>>> expose itself as thermal zone device, registered on the thermal
>>>>>>>> framework.
>>>>>>>>
>>>>>>>> The thermal zone is built only if a device tree node describing
>>>>>>>> a thermal zone for this sensor is present inside the tmp102 DT
>>>>>>>> node. Otherwise, the driver behavior will be the same.
>>>>>>>>
>>>>>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
>>>>>>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
>>>>>>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
>>>>>>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
>>>>>>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
>>>>>>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
>>>>>>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
>>>>>>>> <linux/mutex.h> #include <linux/device.h> #include
>>>>>>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
>>>>>>>> <linux/of.h>
>>>>>>>>
>>>>>>>> #define    DRIVER_NAME "tmp102"
>>>>>>>>
>>>>>>>> @@ -50,6 +52,7 @@
>>>>>>>>
>>>>>>>> struct tmp102 { struct device *hwmon_dev; +    struct
>>>>>>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
>>>>>>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
>>>>>>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
>>>>>>>> tmp102; }
>>>>>>>>
>>>>>>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
>>>>>>>> struct tmp102 *tmp102 =
>>>>>>>> tmp102_update_device(to_i2c_client(dev)); + +    if
>>>>>>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
>>>>>>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
>>>>>>>
>>>>>>> Please drop this warning.
>>>>>>>
>>>>>>
>>>>>> Done for both drivers.
>>>>>>
>>>>>>> Guenter
>>>>>>>
>>>>>>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
>>>>>>>> ssize_t tmp102_show_temp(struct device *dev, struct
>>>>>>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
>>>>>>>> int tmp102_probe(struct i2c_client *client, goto
>>>>>>>> fail_remove_sysfs; }
>>>>>>>>
>>>>>>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
>>>>>>>> 0, +                             &client->dev, +
>>>>>>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
>>>>>>>> dev_warn(&client->dev, +             "Could not parse thermal
>>>>>>>> data in device tree: %ld\n", +
>>>>>>>> PTR_ERR(tmp102->tz));
>>>>>>>
>>>>>>> Please drop this warning. You already create error messages in 
>>>>>>> thermal_zone_of_sensor_register(). That should be sufficient. The
>>>>>>> same applies to the lm75 patch.
>>>>>>
>>>>>> OK. Done for both.
>>>>>>
>>>>>>>
>>>>>>> As a side note, I would suggest to provide devm_ functions for 
>>>>>>> registration. We are introducing those for hwmon registration,
>>>>>>> which enables us to remove most _remove functions. It would be
>>>>>>> great if we can keep it that way.
>>>>>>>
>>>>>>
>>>>>> Right. This side note is taken. Actually this is on my todo list
>>>>>> for quite a while. But I believe this should not block this series,
>>>>>> should it? I will be probably cleaning the thermal framework code
>>>>>> after this current work is accepted at least.
>>>>>>
>>>>>>> On a higher level, I don't think it is a good idea to make
>>>>>>> thermal zones and thermal zone data mandatory. Many systems may
>>>>>>> neither need nor want it.
>>>>>>>
>>>>>>
>>>>>> Well, I agree with you. Did you see something hard required in the
>>>>>> patch I sent. I made it so that it could continue the driver probe
>>>>>> without thermal zones, as you requested.
>>>>>>
>>>>> If it is not mandatory you should not dump an error message to the
>>>>> console in the thermal registration function. Since you do, you at
>>>>> least consider it mandatory if that function is called.
>>>>>
>>>>> So please either drop the error message from the registration
>>>>> function or add a check into the drivers to only register into the
>>>>> thermal subsystem if there is a respective thermal entry for that
>>>>> sensor in the devicetree data.
>>>>>
>>>>> There are systes out there with literally dozens of temperature
>>>>> sensors. In many cases, those are purely for system health
>>>>> monitoring, not for thermal management. I don't want to end up in a
>>>>> situation where users complain about dozens of error messages on the
>>>>> console and no way to avoid it but providing dummy thermal subsystem
>>>>> data.
>>>>>
>>>>
>>>> Now I see.
>>>>
>>>>
>>>> Then I will rollback to the previous version in which lm sensors were
>>>> first probing for thermal properties within their dt node. Something like:
>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
>>>> index dc96598..cb1c663 100644
>>>> --- a/drivers/hwmon/tmp102.c
>>>> +++ b/drivers/hwmon/tmp102.c
>>>> @@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
>>>>                 goto fail_remove_sysfs;
>>>>         }
>>>>
>>>> -       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
>>>> -                                                    &client->dev,
>>>> -                                                    tmp102_read_temp,
>>>> NULL);
>>>> -       if (IS_ERR(tmp102->tz))
>>>> -               tmp102->tz = NULL;
>>>> +       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
>>>> +               tmp102->tz =
>>>> thermal_zone_of_sensor_register(&client->dev, 0,
>>>> +                                                            &client->dev,
>>>> +
>>>> tmp102_read_temp, NULL);
>>>> +               if (IS_ERR(tmp102->tz))
>>>> +                       tmp102->tz = NULL;
>>>> +       }
>>>>
>>>>         dev_info(&client->dev, "initialized\n");
>>>>
>>>>
>>>> Does it sound reasonable?
>>>>
>>> Personally I would prefer if the registration code fails silently.
>>> Pushing the above code into each driver is just adding the same code
>>> repeatedly all over the place.
>>
>> Fair enough. It becomes tedious and just duplicating code. I agree.
>>
>> So I will keep the v2 I just sent and remove the annoying error messages
>> from of-thermal.c while registering the sensors.
>>
>>>
>>> Also, each sensor instance will still result in an error if there
>>> is no global "thermal-zones" entry. Checking for that global entry
>>> in each driver would be even more excessive, and I just don't like
>>> that noisyness.
>>>
>>> Also, I think you'll need to create devicetree bindings documents
>>> for the two sensors.
>>>
>>
>> Why would I? There is only one extra property and that is already
>> documented. I think the sensor still falls into the dummy dt node.
>>
> I'll leave that up to the devicetree folks to decide.

OK. Fair enough. Let s see what they have to say. Mark, Pawel, Stephen?

Guenter, any other objections a part from those I already fixed?

> 
> Guenter
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On Wed, Sep 18, 2013 at 12:23:31PM -0400, Eduardo Valentin wrote:
> On 18-09-2013 11:57, Guenter Roeck wrote:
> > On Wed, Sep 18, 2013 at 11:54:18AM -0400, Eduardo Valentin wrote:
> >> On 18-09-2013 11:17, Guenter Roeck wrote:
> >>> On Wed, Sep 18, 2013 at 10:29:09AM -0400, Eduardo Valentin wrote:
> >>>> On 18-09-2013 07:18, Guenter Roeck wrote:
> >>>>> On Tue, Sep 17, 2013 at 06:29:45PM -0400, Eduardo Valentin wrote:
> >>>>>> On 15-09-2013 19:33, Guenter Roeck wrote:
> >>>>>>> On 09/15/2013 03:02 PM, Eduardo Valentin wrote:
> >>>>>>>> This patch adds to tmp102 temperature sensor the possibility to
> >>>>>>>> expose itself as thermal zone device, registered on the thermal
> >>>>>>>> framework.
> >>>>>>>>
> >>>>>>>> The thermal zone is built only if a device tree node describing
> >>>>>>>> a thermal zone for this sensor is present inside the tmp102 DT
> >>>>>>>> node. Otherwise, the driver behavior will be the same.
> >>>>>>>>
> >>>>>>>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org> Cc: Guenter Roeck
> >>>>>>>> <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Cc:
> >>>>>>>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Eduardo Valentin
> >>>>>>>> <eduardo.valentin-l0cyMroinI0@public.gmane.org> --- drivers/hwmon/tmp102.c | 28
> >>>>>>>> ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
> >>>>>>>>
> >>>>>>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c 
> >>>>>>>> index d7b47ab..e432444 100644 --- a/drivers/hwmon/tmp102.c +++
> >>>>>>>> b/drivers/hwmon/tmp102.c @@ -27,6 +27,8 @@ #include
> >>>>>>>> <linux/mutex.h> #include <linux/device.h> #include
> >>>>>>>> <linux/jiffies.h> +#include <linux/thermal.h> +#include
> >>>>>>>> <linux/of.h>
> >>>>>>>>
> >>>>>>>> #define    DRIVER_NAME "tmp102"
> >>>>>>>>
> >>>>>>>> @@ -50,6 +52,7 @@
> >>>>>>>>
> >>>>>>>> struct tmp102 { struct device *hwmon_dev; +    struct
> >>>>>>>> thermal_zone_device *tz; struct mutex lock; u16 config_orig; 
> >>>>>>>> unsigned long last_update; @@ -93,6 +96,19 @@ static struct
> >>>>>>>> tmp102 *tmp102_update_device(struct i2c_client *client) return
> >>>>>>>> tmp102; }
> >>>>>>>>
> >>>>>>>> +static int tmp102_read_temp(void *dev, long *temp) +{ +
> >>>>>>>> struct tmp102 *tmp102 =
> >>>>>>>> tmp102_update_device(to_i2c_client(dev)); + +    if
> >>>>>>>> (tmp102->temp[0] < 0) +        dev_warn(tmp102->hwmon_dev, +
> >>>>>>>> "operating in negative temp: %d\n", tmp102->temp[0]); +
> >>>>>>>
> >>>>>>> Please drop this warning.
> >>>>>>>
> >>>>>>
> >>>>>> Done for both drivers.
> >>>>>>
> >>>>>>> Guenter
> >>>>>>>
> >>>>>>>> +    *temp = tmp102->temp[0]; + +    return 0; +} + static
> >>>>>>>> ssize_t tmp102_show_temp(struct device *dev, struct
> >>>>>>>> device_attribute *attr, char *buf) @@ -204,6 +220,16 @@ static
> >>>>>>>> int tmp102_probe(struct i2c_client *client, goto
> >>>>>>>> fail_remove_sysfs; }
> >>>>>>>>
> >>>>>>>> +    tmp102->tz = thermal_zone_of_sensor_register(&client->dev,
> >>>>>>>> 0, +                             &client->dev, +
> >>>>>>>> tmp102_read_temp, NULL); +    if (IS_ERR(tmp102->tz)) { +
> >>>>>>>> dev_warn(&client->dev, +             "Could not parse thermal
> >>>>>>>> data in device tree: %ld\n", +
> >>>>>>>> PTR_ERR(tmp102->tz));
> >>>>>>>
> >>>>>>> Please drop this warning. You already create error messages in 
> >>>>>>> thermal_zone_of_sensor_register(). That should be sufficient. The
> >>>>>>> same applies to the lm75 patch.
> >>>>>>
> >>>>>> OK. Done for both.
> >>>>>>
> >>>>>>>
> >>>>>>> As a side note, I would suggest to provide devm_ functions for 
> >>>>>>> registration. We are introducing those for hwmon registration,
> >>>>>>> which enables us to remove most _remove functions. It would be
> >>>>>>> great if we can keep it that way.
> >>>>>>>
> >>>>>>
> >>>>>> Right. This side note is taken. Actually this is on my todo list
> >>>>>> for quite a while. But I believe this should not block this series,
> >>>>>> should it? I will be probably cleaning the thermal framework code
> >>>>>> after this current work is accepted at least.
> >>>>>>
> >>>>>>> On a higher level, I don't think it is a good idea to make
> >>>>>>> thermal zones and thermal zone data mandatory. Many systems may
> >>>>>>> neither need nor want it.
> >>>>>>>
> >>>>>>
> >>>>>> Well, I agree with you. Did you see something hard required in the
> >>>>>> patch I sent. I made it so that it could continue the driver probe
> >>>>>> without thermal zones, as you requested.
> >>>>>>
> >>>>> If it is not mandatory you should not dump an error message to the
> >>>>> console in the thermal registration function. Since you do, you at
> >>>>> least consider it mandatory if that function is called.
> >>>>>
> >>>>> So please either drop the error message from the registration
> >>>>> function or add a check into the drivers to only register into the
> >>>>> thermal subsystem if there is a respective thermal entry for that
> >>>>> sensor in the devicetree data.
> >>>>>
> >>>>> There are systes out there with literally dozens of temperature
> >>>>> sensors. In many cases, those are purely for system health
> >>>>> monitoring, not for thermal management. I don't want to end up in a
> >>>>> situation where users complain about dozens of error messages on the
> >>>>> console and no way to avoid it but providing dummy thermal subsystem
> >>>>> data.
> >>>>>
> >>>>
> >>>> Now I see.
> >>>>
> >>>>
> >>>> Then I will rollback to the previous version in which lm sensors were
> >>>> first probing for thermal properties within their dt node. Something like:
> >>>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
> >>>> index dc96598..cb1c663 100644
> >>>> --- a/drivers/hwmon/tmp102.c
> >>>> +++ b/drivers/hwmon/tmp102.c
> >>>> @@ -216,11 +216,13 @@ static int tmp102_probe(struct i2c_client *client,
> >>>>                 goto fail_remove_sysfs;
> >>>>         }
> >>>>
> >>>> -       tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
> >>>> -                                                    &client->dev,
> >>>> -                                                    tmp102_read_temp,
> >>>> NULL);
> >>>> -       if (IS_ERR(tmp102->tz))
> >>>> -               tmp102->tz = NULL;
> >>>> +       if ((of_find_property(client->dev.of_node, "#sensor-cells", NULL)) {
> >>>> +               tmp102->tz =
> >>>> thermal_zone_of_sensor_register(&client->dev, 0,
> >>>> +                                                            &client->dev,
> >>>> +
> >>>> tmp102_read_temp, NULL);
> >>>> +               if (IS_ERR(tmp102->tz))
> >>>> +                       tmp102->tz = NULL;
> >>>> +       }
> >>>>
> >>>>         dev_info(&client->dev, "initialized\n");
> >>>>
> >>>>
> >>>> Does it sound reasonable?
> >>>>
> >>> Personally I would prefer if the registration code fails silently.
> >>> Pushing the above code into each driver is just adding the same code
> >>> repeatedly all over the place.
> >>
> >> Fair enough. It becomes tedious and just duplicating code. I agree.
> >>
> >> So I will keep the v2 I just sent and remove the annoying error messages
> >> from of-thermal.c while registering the sensors.
> >>
> >>>
> >>> Also, each sensor instance will still result in an error if there
> >>> is no global "thermal-zones" entry. Checking for that global entry
> >>> in each driver would be even more excessive, and I just don't like
> >>> that noisyness.
> >>>
> >>> Also, I think you'll need to create devicetree bindings documents
> >>> for the two sensors.
> >>>
> >>
> >> Why would I? There is only one extra property and that is already
> >> documented. I think the sensor still falls into the dummy dt node.
> >>
> > I'll leave that up to the devicetree folks to decide.
> 
> OK. Fair enough. Let s see what they have to say. Mark, Pawel, Stephen?
> 
> Guenter, any other objections a part from those I already fixed?
> 
Not in the drivers, except that I am quite sure that the unregister call
will cause a NULL pointer access if the passed thermal zone is NULL.
I'll comment on that separetely in the related patch.

Guenter
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[PATCHv2 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to tmp102 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the tmp102 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
---
 drivers/hwmon/tmp102.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

---

Guenter,

Here is a version without the warnings, as requested.

Eduardo

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index d7b47ab..dc96598 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -27,6 +27,8 @@
 #include <linux/mutex.h>
 #include <linux/device.h>
 #include <linux/jiffies.h>
+#include <linux/thermal.h>
+#include <linux/of.h>
 
 #define	DRIVER_NAME "tmp102"
 
@@ -50,6 +52,7 @@
 
 struct tmp102 {
 	struct device *hwmon_dev;
+	struct thermal_zone_device *tz;
 	struct mutex lock;
 	u16 config_orig;
 	unsigned long last_update;
@@ -93,6 +96,15 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
 	return tmp102;
 }
 
+static int tmp102_read_temp(void *dev, long *temp)
+{
+	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
+
+	*temp = tmp102->temp[0];
+
+	return 0;
+}
+
 static ssize_t tmp102_show_temp(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
@@ -204,6 +216,12 @@ static int tmp102_probe(struct i2c_client *client,
 		goto fail_remove_sysfs;
 	}
 
+	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
+						     &client->dev,
+						     tmp102_read_temp, NULL);
+	if (IS_ERR(tmp102->tz))
+		tmp102->tz = NULL;
+
 	dev_info(&client->dev, "initialized\n");
 
 	return 0;
@@ -220,6 +238,8 @@ static int tmp102_remove(struct i2c_client *client)
 {
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);
 
+	/* thermal zone life cycle is not our responsibility */
+	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
 	hwmon_device_unregister(tmp102->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
 
-- 
1.8.2.1.342.gfa7285d

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Re: [PATCHv2 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On Tue, Sep 17, 2013 at 06:34:05PM -0400, Eduardo Valentin wrote:
> This patch adds to tmp102 temperature sensor the possibility
> to expose itself as thermal zone device, registered on the
> thermal framework.
> 
> The thermal zone is built only if a device tree node
> describing a thermal zone for this sensor is present
> inside the tmp102 DT node. Otherwise, the driver behavior
> will be the same.
> 
> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
> ---
>  drivers/hwmon/tmp102.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> ---
> 
> Guenter,
> 
> Here is a version without the warnings, as requested.
> 
> Eduardo
> 
> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
> index d7b47ab..dc96598 100644
> --- a/drivers/hwmon/tmp102.c
> +++ b/drivers/hwmon/tmp102.c
> @@ -27,6 +27,8 @@
>  #include <linux/mutex.h>
>  #include <linux/device.h>
>  #include <linux/jiffies.h>
> +#include <linux/thermal.h>
> +#include <linux/of.h>
>  
>  #define	DRIVER_NAME "tmp102"
>  
> @@ -50,6 +52,7 @@
>  
>  struct tmp102 {
>  	struct device *hwmon_dev;
> +	struct thermal_zone_device *tz;
>  	struct mutex lock;
>  	u16 config_orig;
>  	unsigned long last_update;
> @@ -93,6 +96,15 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
>  	return tmp102;
>  }
>  
> +static int tmp102_read_temp(void *dev, long *temp)
> +{
> +	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
> +
> +	*temp = tmp102->temp[0];
> +
> +	return 0;
> +}
> +
>  static ssize_t tmp102_show_temp(struct device *dev,
>  				struct device_attribute *attr,
>  				char *buf)
> @@ -204,6 +216,12 @@ static int tmp102_probe(struct i2c_client *client,
>  		goto fail_remove_sysfs;
>  	}
>  
> +	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
> +						     &client->dev,
> +						     tmp102_read_temp, NULL);
> +	if (IS_ERR(tmp102->tz))
> +		tmp102->tz = NULL;
> +
>  	dev_info(&client->dev, "initialized\n");
>  
>  	return 0;
> @@ -220,6 +238,8 @@ static int tmp102_remove(struct i2c_client *client)
>  {
>  	struct tmp102 *tmp102 = i2c_get_clientdata(client);
>  
> +	/* thermal zone life cycle is not our responsibility */

This comment does not provide any value. Please drop it from both drivers.
Sorry I missed that earlier.

> +	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
>  	hwmon_device_unregister(tmp102->hwmon_dev);
>  	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
>  
> -- 
> 1.8.2.1.342.gfa7285d
> 
> 
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Re: [PATCHv2 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

[-- Attachment #1: Type: text/plain, Size: 3201 bytes --]

On 18-09-2013 07:06, Guenter Roeck wrote:
> On Tue, Sep 17, 2013 at 06:34:05PM -0400, Eduardo Valentin wrote:
>> This patch adds to tmp102 temperature sensor the possibility
>> to expose itself as thermal zone device, registered on the
>> thermal framework.
>>
>> The thermal zone is built only if a device tree node
>> describing a thermal zone for this sensor is present
>> inside the tmp102 DT node. Otherwise, the driver behavior
>> will be the same.
>>
>> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
>> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
>> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
>> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>
>> ---
>>  drivers/hwmon/tmp102.c | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> ---
>>
>> Guenter,
>>
>> Here is a version without the warnings, as requested.
>>
>> Eduardo
>>
>> diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
>> index d7b47ab..dc96598 100644
>> --- a/drivers/hwmon/tmp102.c
>> +++ b/drivers/hwmon/tmp102.c
>> @@ -27,6 +27,8 @@
>>  #include <linux/mutex.h>
>>  #include <linux/device.h>
>>  #include <linux/jiffies.h>
>> +#include <linux/thermal.h>
>> +#include <linux/of.h>
>>  
>>  #define	DRIVER_NAME "tmp102"
>>  
>> @@ -50,6 +52,7 @@
>>  
>>  struct tmp102 {
>>  	struct device *hwmon_dev;
>> +	struct thermal_zone_device *tz;
>>  	struct mutex lock;
>>  	u16 config_orig;
>>  	unsigned long last_update;
>> @@ -93,6 +96,15 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
>>  	return tmp102;
>>  }
>>  
>> +static int tmp102_read_temp(void *dev, long *temp)
>> +{
>> +	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
>> +
>> +	*temp = tmp102->temp[0];
>> +
>> +	return 0;
>> +}
>> +
>>  static ssize_t tmp102_show_temp(struct device *dev,
>>  				struct device_attribute *attr,
>>  				char *buf)
>> @@ -204,6 +216,12 @@ static int tmp102_probe(struct i2c_client *client,
>>  		goto fail_remove_sysfs;
>>  	}
>>  
>> +	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
>> +						     &client->dev,
>> +						     tmp102_read_temp, NULL);
>> +	if (IS_ERR(tmp102->tz))
>> +		tmp102->tz = NULL;
>> +
>>  	dev_info(&client->dev, "initialized\n");
>>  
>>  	return 0;
>> @@ -220,6 +238,8 @@ static int tmp102_remove(struct i2c_client *client)
>>  {
>>  	struct tmp102 *tmp102 = i2c_get_clientdata(client);
>>  
>> +	/* thermal zone life cycle is not our responsibility */
> 
> This comment does not provide any value. Please drop it from both drivers.
> Sorry I missed that earlier.

Yeah, I even forgot to drop it myself. No problem, I am resending both
without it.

> 
>> +	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
>>  	hwmon_device_unregister(tmp102->hwmon_dev);
>>  	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
>>  
>> -- 
>> 1.8.2.1.342.gfa7285d
>>
>>
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 295 bytes --]

[PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Eduardo Valentin]

This patch adds to tmp102 temperature sensor the possibility
to expose itself as thermal zone device, registered on the
thermal framework.

The thermal zone is built only if a device tree node
describing a thermal zone for this sensor is present
inside the tmp102 DT node. Otherwise, the driver behavior
will be the same.

Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: lm-sensors@lm-sensors.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 drivers/hwmon/tmp102.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
---
Hi Guenter,

Very minor change, removing comment, as requested.

Eduardo

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index d7b47ab..6748b45 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -27,6 +27,8 @@
 #include <linux/mutex.h>
 #include <linux/device.h>
 #include <linux/jiffies.h>
+#include <linux/thermal.h>
+#include <linux/of.h>
 
 #define	DRIVER_NAME "tmp102"
 
@@ -50,6 +52,7 @@
 
 struct tmp102 {
 	struct device *hwmon_dev;
+	struct thermal_zone_device *tz;
 	struct mutex lock;
 	u16 config_orig;
 	unsigned long last_update;
@@ -93,6 +96,15 @@ static struct tmp102 *tmp102_update_device(struct i2c_client *client)
 	return tmp102;
 }
 
+static int tmp102_read_temp(void *dev, long *temp)
+{
+	struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
+
+	*temp = tmp102->temp[0];
+
+	return 0;
+}
+
 static ssize_t tmp102_show_temp(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
@@ -204,6 +216,12 @@ static int tmp102_probe(struct i2c_client *client,
 		goto fail_remove_sysfs;
 	}
 
+	tmp102->tz = thermal_zone_of_sensor_register(&client->dev, 0,
+						     &client->dev,
+						     tmp102_read_temp, NULL);
+	if (IS_ERR(tmp102->tz))
+		tmp102->tz = NULL;
+
 	dev_info(&client->dev, "initialized\n");
 
 	return 0;
@@ -220,6 +238,7 @@ static int tmp102_remove(struct i2c_client *client)
 {
 	struct tmp102 *tmp102 = i2c_get_clientdata(client);
 
+	thermal_zone_of_sensor_unregister(&client->dev, tmp102->tz);
 	hwmon_device_unregister(tmp102->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
 
-- 
1.8.2.1.342.gfa7285d

Re: [PATCH 06/16] hwmon: tmp102: expose to thermal fw via DT nodes

[Guenter Roeck]

On 09/18/2013 09:23 AM, Eduardo Valentin wrote:
> This patch adds to tmp102 temperature sensor the possibility
> to expose itself as thermal zone device, registered on the
> thermal framework.
>
> The thermal zone is built only if a device tree node
> describing a thermal zone for this sensor is present
> inside the tmp102 DT node. Otherwise, the driver behavior
> will be the same.
>
> Cc: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
> Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>
> Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
> Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin-l0cyMroinI0@public.gmane.org>

Acked-by: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>


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[PATCH 08/16] arm: dts: add omap4 CPU thermal data

[Eduardo Valentin]

This patch changes a dtsi file to contain the thermal data
for MPU domain on OMAP4 and later SoCs. This data will
enable the passive cooling with CPUfreq cooling device
at 100C and the system will do a thermal shutdown at 125C.

This thermal data can be reused across TI SoC devices.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap4-cpu-thermal.dtsi | 41 ++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 arch/arm/boot/dts/omap4-cpu-thermal.dtsi

diff --git a/arch/arm/boot/dts/omap4-cpu-thermal.dtsi b/arch/arm/boot/dts/omap4-cpu-thermal.dtsi
new file mode 100644
index 0000000..dd69788
--- /dev/null
+++ b/arch/arm/boot/dts/omap4-cpu-thermal.dtsi
@@ -0,0 +1,41 @@
+/*
+ * Device Tree Source for OMAP4/5 SoC CPU thermal
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
+ * Contact: Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <dt-bindings/thermal/thermal.h>
+
+cpu_thermal: cpu_thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+        sensors = <&bandgap     0>;
+
+        trips {
+                cpu_alert0: cpu_alert {
+                        temperature = <100000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_PASSIVE>;
+                };
+                cpu_crit: cpu_crit {
+                        temperature = <125000>; /* milliCelsius */
+                        hysteresis = <2000>; /* milliCelsius */
+                        type = <THERMAL_TRIP_CRITICAL>;
+                };
+        };
+
+	cooling-attachments {
+		attach0 {
+			trip = <&cpu_alert0>;
+			cooling-device =
+				<&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+		};
+	};
+};
-- 
1.8.2.1.342.gfa7285d


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[PATCH 09/16] arm: dts: add omap4430 thermal data

[Eduardo Valentin]

This patch changes the dtsi entry on omap4430 to contain
the thermal data. This data will enable the passive
cooling with CPUfreq cooling device at 100C and the
system will do a thermal shutdown at 125C.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap443x.dtsi | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/omap443x.dtsi b/arch/arm/boot/dts/omap443x.dtsi
index bcf455e..6987df9 100644
--- a/arch/arm/boot/dts/omap443x.dtsi
+++ b/arch/arm/boot/dts/omap443x.dtsi
@@ -12,7 +12,7 @@
 
 / {
 	cpus {
-		cpu@0 {
+		cpu0: cpu@0 {
 			/* OMAP443x variants OPP50-OPPNT */
 			operating-points = <
 				/* kHz    uV */
@@ -25,9 +25,15 @@
 		};
 	};
 
-	bandgap {
+	thermal-zones{
+		#include "omap4-cpu-thermal.dtsi"
+	};
+
+	bandgap: bandgap {
 		reg = <0x4a002260 0x4
 		       0x4a00232C 0x4>;
 		compatible = "ti,omap4430-bandgap";
+
+		#sensor-cells = <1>;
 	};
 };
-- 
1.8.2.1.342.gfa7285d


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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 10/16] arm: dts: add omap4460 thermal data

[Eduardo Valentin]

This patch changes the dtsi entry on omap4460 to contain
the thermal data. This data will enable the passive
cooling with CPUfreq cooling device at 100C and the
system will do a thermal shutdown at 125C.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap4460.dtsi | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/omap4460.dtsi b/arch/arm/boot/dts/omap4460.dtsi
index c2f0f39..b6b9b83 100644
--- a/arch/arm/boot/dts/omap4460.dtsi
+++ b/arch/arm/boot/dts/omap4460.dtsi
@@ -12,7 +12,7 @@
 / {
 	cpus {
 		/* OMAP446x 'standard device' variants OPP50 to OPPTurbo */
-		cpu@0 {
+		cpu0: cpu@0 {
 			operating-points = <
 				/* kHz    uV */
 				350000  1025000
@@ -30,12 +30,18 @@
 		ti,hwmods = "debugss";
 	};
 
-	bandgap {
+	thermal-zones{
+		#include "omap4-cpu-thermal.dtsi"
+	};
+
+	bandgap: bandgap {
 		reg = <0x4a002260 0x4
 		       0x4a00232C 0x4
 		       0x4a002378 0x18>;
 		compatible = "ti,omap4460-bandgap";
 		interrupts = <0 126 IRQ_TYPE_LEVEL_HIGH>; /* talert */
 		gpios = <&gpio3 22 0>; /* tshut */
+
+		#sensor-cells = <1>;
 	};
 };
-- 
1.8.2.1.342.gfa7285d

[PATCH 11/16] arm: dts: add cooling properties on omap4430 cpu node

[Eduardo Valentin]

OMAP4430 devices can reach high temperatures and thus
needs to have cpufreq-cooling on systems running on it.

This patch adds the required cooling device properties
so that cpufreq-cpu0 driver loads the cooling device.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap443x.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/omap443x.dtsi b/arch/arm/boot/dts/omap443x.dtsi
index 6987df9..5737e49 100644
--- a/arch/arm/boot/dts/omap443x.dtsi
+++ b/arch/arm/boot/dts/omap443x.dtsi
@@ -22,6 +22,11 @@
 				1008000 1375000
 			>;
 			clock-latency = <300000>; /* From legacy driver */
+
+			/* cooling options */
+			cooling-min-level = <0>;
+			cooling-max-level = <3>;
+			#cooling-cells = <2>; /* min followed by max */
 		};
 	};
 
-- 
1.8.2.1.342.gfa7285d

[PATCH 12/16] arm: dts: add cooling properties on omap4460 cpu node

[Eduardo Valentin]

OMAP4460 devices can reach high temperatures and thus
needs to have cpufreq-cooling on systems running on it.

This patch adds the required cooling device properties
so that cpufreq-cpu0 driver loads the cooling device.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap4460.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/omap4460.dtsi b/arch/arm/boot/dts/omap4460.dtsi
index b6b9b83..0806f03 100644
--- a/arch/arm/boot/dts/omap4460.dtsi
+++ b/arch/arm/boot/dts/omap4460.dtsi
@@ -20,6 +20,11 @@
 				920000  1313000
 			>;
 			clock-latency = <300000>; /* From legacy driver */
+
+			/* cooling options */
+			cooling-min-level = <0>;
+			cooling-max-level = <2>;
+			#cooling-cells = <2>; /* min followed by max */
 		};
 	};
 
-- 
1.8.2.1.342.gfa7285d

[PATCH 13/16] arm: dts: add omap5 GPU thermal data

[Eduardo Valentin]

This patch changes a dtsi file to contain the thermal data
for GPU domain on OMAP5 and later SoCs. This data will
enable a thermal shutdown at 125C.

This thermal data can be reused across TI SoC devices.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap5-gpu-thermal.dtsi | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 arch/arm/boot/dts/omap5-gpu-thermal.dtsi

diff --git a/arch/arm/boot/dts/omap5-gpu-thermal.dtsi b/arch/arm/boot/dts/omap5-gpu-thermal.dtsi
new file mode 100644
index 0000000..08a1290
--- /dev/null
+++ b/arch/arm/boot/dts/omap5-gpu-thermal.dtsi
@@ -0,0 +1,28 @@
+/*
+ * Device Tree Source for OMAP543x SoC GPU thermal
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
+ * Contact: Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <dt-bindings/thermal/thermal.h>
+
+gpu_thermal: gpu_thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+	sensors = <&bandgap     1>;
+
+	trips {
+		gpu_crit: gpu_crit {
+			temperature = <125000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_CRITICAL>;
+		};
+	};
+};
-- 
1.8.2.1.342.gfa7285d


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[PATCH 14/16] arm: dts: add omap5 CORE thermal data

[Eduardo Valentin]

This patch changes a dtsi file to contain the thermal data
for CORE domain on OMAP5 and later SoCs. This data will
enable a thermal shutdown at 125C.

This thermal data can be reused across TI SoC devices.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap5-core-thermal.dtsi | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 arch/arm/boot/dts/omap5-core-thermal.dtsi

diff --git a/arch/arm/boot/dts/omap5-core-thermal.dtsi b/arch/arm/boot/dts/omap5-core-thermal.dtsi
new file mode 100644
index 0000000..1fdd32e
--- /dev/null
+++ b/arch/arm/boot/dts/omap5-core-thermal.dtsi
@@ -0,0 +1,28 @@
+/*
+ * Device Tree Source for OMAP543x SoC CORE thermal
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
+ * Contact: Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <dt-bindings/thermal/thermal.h>
+
+core_thermal: core_thermal {
+	passive-delay = <250>; /* milliseconds */
+	polling-delay = <1000>; /* milliseconds */
+
+		/* sensor       ID */
+	sensors = <&bandgap     2>;
+
+	trips {
+		core_crit: core_crit {
+			temperature = <125000>; /* milliCelsius */
+			hysteresis = <2000>; /* milliCelsius */
+			type = <THERMAL_TRIP_CRITICAL>;
+		};
+	};
+};
-- 
1.8.2.1.342.gfa7285d

[PATCH 15/16] arm: dts: add omap5 thermal data

[Eduardo Valentin]

This patch changes the dtsi entry on omap5 to contain
the thermal data. This data will enable the passive
cooling with CPUfreq cooling device at 100C. The
system will do a thermal shutdown at 125C whenever
any of its sensors sees this level.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap5.dtsi | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
index 07be2cd..b2ca0cf 100644
--- a/arch/arm/boot/dts/omap5.dtsi
+++ b/arch/arm/boot/dts/omap5.dtsi
@@ -33,7 +33,7 @@
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-		cpu@0 {
+		cpu0: cpu@0 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a15";
 			reg = <0x0>;
@@ -45,6 +45,12 @@
 		};
 	};
 
+	thermal-zones {
+		#include "omap4-cpu-thermal.dtsi"
+		#include "omap5-gpu-thermal.dtsi"
+		#include "omap5-core-thermal.dtsi"
+	};
+
 	timer {
 		compatible = "arm,armv7-timer";
 		/* PPI secure/nonsecure IRQ */
@@ -704,13 +710,15 @@
 			};
 		};
 
-		bandgap@4a0021e0 {
+		bandgap: bandgap@4a0021e0 {
 			reg = <0x4a0021e0 0xc
 			       0x4a00232c 0xc
 			       0x4a002380 0x2c
 			       0x4a0023C0 0x3c>;
 			interrupts = <GIC_SPI 126 IRQ_TYPE_LEVEL_HIGH>;
 			compatible = "ti,omap5430-bandgap";
+
+			#sensor-cells = <1>;
 		};
 	};
 };
-- 
1.8.2.1.342.gfa7285d

[PATCH 16/16] arm: dts: add cooling properties on omap5 cpu node

[Eduardo Valentin]

OMAP5 devices can reach high temperatures and thus
needs to have cpufreq-cooling on systems running on it.

This patch adds the required cooling device properties
so that cpufreq-cpu0 driver loads the cooling device.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-omap@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 arch/arm/boot/dts/omap5.dtsi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
index b2ca0cf..9eb95b7 100644
--- a/arch/arm/boot/dts/omap5.dtsi
+++ b/arch/arm/boot/dts/omap5.dtsi
@@ -37,6 +37,9 @@
 			device_type = "cpu";
 			compatible = "arm,cortex-a15";
 			reg = <0x0>;
+
+			/* cooling options */
+			#cooling-cells = <2>; /* min followed by max */
 		};
 		cpu@1 {
 			device_type = "cpu";
-- 
1.8.2.1.342.gfa7285d