[PATCH V3 0/5] bcm2835: add thermal driver

[PATCH V3 0/5] bcm2835: add thermal driver

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add a thermal driver for the TSENSE device of the bcm2835 SOC.

If the firmware enables the HW, then the configuration is not touched.
In case the firmware has not enabled the device, then we try to set
it up correctly (which unfortunately can not get tested).

It exposes temperature and a critical trip point
(using a hardcoded default of 80C or the temperature configured
in the control register by the firmware, which reads as
407C currently)

The calibrations are (potentially) different for bcm2835, bcm2836
and bcm2837 and can get selected by the compatible property
in the device tree.

The driver also exposes the registers via debugfs.

Possible future enhancements:
* the device has the ability to trigger interrupts on reaching
  the programmed critical temperature.
  I have no knowledge which interrupt could be responsible
  for this on the ARM side, so if we get to know which irq
  it is we can implement that
* the device can also reset the HW after the trip point
  has been reached (also with some delay, so that corrective
  actions can get taken) - this is currently not enabled by the
  firmware, but could.
* we could define more trip points for THERMAL_TRIP_HOT
* make the trip point limits modifiable (ops.set_trip_temp)

Changelog:
 V1 -> V2: renamed dt-binding documentation file
       	   added specific settings depending on compatible
	   added trip point based on register
	   setting up ctrl-register if HW is not enabled by firmware
	     as per recommendation of Eric (untested)
	   check that clock frequency is in range
	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
 	   added driver to multi_v7_defconfig
 V2 -> V3: made a module in multi_v7_defconfig
           fixed typo in dt-binding document

Martin Sperl (5):
  dt: bindings: add thermal device driver for bcm2835
  thermal: bcm2835: add thermal driver for bcm2835 soc
  ARM: bcm2835: add thermal node to device-tree of bcm283x
  ARM: bcm2835: add thermal driver to default_config
  ARM: multi_v7_defconfig: bcm2835: add bcm2835-thermal driver

 .../bindings/thermal/brcm,bcm2835-thermal.txt      |  17 ++
 arch/arm/boot/dts/bcm283x.dtsi                     |   6 +
 arch/arm/configs/bcm2835_defconfig                 |   2 +
 arch/arm/configs/multi_v7_defconfig                |   1 +
 drivers/thermal/Kconfig                            |   5 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/bcm/Kconfig                        |   4 +
 drivers/thermal/bcm/Makefile                       |   1 +
 drivers/thermal/bcm/bcm2835_thermal.c              | 326 +++++++++++++++++++++
 9 files changed, 363 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
 create mode 100644 drivers/thermal/bcm/Kconfig
 create mode 100644 drivers/thermal/bcm/Makefile
 create mode 100644 drivers/thermal/bcm/bcm2835_thermal.c

--
2.1.4

[PATCH V3 1/5] dt: bindings: add thermal device driver for bcm2835

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add dt-binding documentation for bcm2835 SOC thermal sensor.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>

Changelog:
 V1 -> V2: renamed file to follow naming conventions
 V2 -> V3: removed 0x in node name
---
 .../bindings/thermal/brcm,bcm2835-thermal.txt           | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt

diff --git a/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt b/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
new file mode 100644
index 0000000..474531d
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/brcm,bcm2835-thermal.txt
@@ -0,0 +1,17 @@
+Binding for Thermal Sensor driver for BCM2835 SoCs.
+
+Required parameters:
+-------------------
+
+compatible: 	should be one of: "brcm,bcm2835-thermal",
+		"brcm,bcm2836-thermal" or "brcm,bcm2837-thermal"
+reg:		Address range of the thermal registers.
+clocks: 	Phandle of the clock used by the thermal sensor.
+
+Example:
+
+thermal: thermal@7e212000 {
+	compatible = "brcm,bcm2835-thermal";
+	reg = <0x7e212000 0x8>;
+	clocks = <&clocks BCM2835_CLOCK_TSENS>;
+};
--
2.1.4

[PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add basic thermal driver for bcm2835 SOC.

This driver currently relies on the firmware setting up the
tsense HW block and does not set it up itself.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>

ChangeLog:
 V1 -> V2: added specific settings depending on compatiblity
	   added trip point based on register
	   setting up ctrl-register if HW is not enabled by firmware
	     as per recommendation of Eric (untested)
	   check that clock frequency is in range
	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
---
 drivers/thermal/Kconfig               |   5 +
 drivers/thermal/Makefile              |   1 +
 drivers/thermal/bcm/Kconfig           |   4 +
 drivers/thermal/bcm/Makefile          |   1 +
 drivers/thermal/bcm/bcm2835_thermal.c | 326 ++++++++++++++++++++++++++++++++++
 5 files changed, 337 insertions(+)
 create mode 100644 drivers/thermal/bcm/Kconfig
 create mode 100644 drivers/thermal/bcm/Makefile
 create mode 100644 drivers/thermal/bcm/bcm2835_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3c3dc4a..5b63d45 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -383,6 +383,11 @@ config MTK_THERMAL
 	  Enable this option if you want to have support for thermal management
 	  controller present in Mediatek SoCs
 
+menu "Broadcom thermal drivers"
+depends on ARCH_BCM || COMPILE_TEST
+source "drivers/thermal/bcm/Kconfig"
+endmenu
+
 menu "Texas Instruments thermal drivers"
 depends on ARCH_HAS_BANDGAP || COMPILE_TEST
 depends on HAS_IOMEM
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 8e9cbc3..6df1aa3 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -49,3 +49,4 @@ obj-$(CONFIG_ST_THERMAL)	+= st/
 obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
 obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
+obj-y				+= bcm/
diff --git a/drivers/thermal/bcm/Kconfig b/drivers/thermal/bcm/Kconfig
new file mode 100644
index 0000000..62245ae
--- /dev/null
+++ b/drivers/thermal/bcm/Kconfig
@@ -0,0 +1,4 @@
+config BCM2835_THERMAL
+       tristate "Thermal sensors on bcm2835 SoC"
+       help
+         Support for thermal sensors on Broadcom bcm2835 SoCs.
diff --git a/drivers/thermal/bcm/Makefile b/drivers/thermal/bcm/Makefile
new file mode 100644
index 0000000..13456d2
--- /dev/null
+++ b/drivers/thermal/bcm/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_BCM2835_THERMAL)		:= bcm2835_thermal.o
diff --git a/drivers/thermal/bcm/bcm2835_thermal.c b/drivers/thermal/bcm/bcm2835_thermal.c
new file mode 100644
index 0000000..73138cb
--- /dev/null
+++ b/drivers/thermal/bcm/bcm2835_thermal.c
@@ -0,0 +1,326 @@
+/*
+ * Driver for Broadcom BCM2835 soc temperature sensor
+ *
+ * Copyright (C) 2015 Martin Sperl
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#define BCM2835_TS_TSENSCTL			0x00
+#define BCM2835_TS_TSENSSTAT			0x04
+
+#define BCM2835_TS_TSENSCTL_PRWDW		BIT(0)
+#define BCM2835_TS_TSENSCTL_RSTB		BIT(1)
+#define BCM2835_TS_TSENSCTL_CTRL_BITS		3
+#define BCM2835_TS_TSENSCTL_CTRL_SHIFT		2
+#define BCM2835_TS_TSENSCTL_CTRL_MASK		    \
+	GENMASK(BCM2835_TS_TSENSCTL_CTRL_BITS +     \
+		BCM2835_TS_TSENSCTL_CTRL_SHIFT - 1, \
+		BCM2835_TS_TSENSCTL_CTRL_SHIFT)
+#define BCM2835_TS_TSENSCTL_CTRL_DEFAULT	1
+#define BCM2835_TS_TSENSCTL_EN_INT		BIT(5)
+#define BCM2835_TS_TSENSCTL_DIRECT		BIT(6)
+#define BCM2835_TS_TSENSCTL_CLR_INT		BIT(7)
+#define BCM2835_TS_TSENSCTL_THOLD_SHIFT		8
+#define BCM2835_TS_TSENSCTL_THOLD_BITS		10
+#define BCM2835_TS_TSENSCTL_THOLD_MASK		     \
+	GENMASK(BCM2835_TS_TSENSCTL_THOLD_BITS +     \
+		BCM2835_TS_TSENSCTL_THOLD_SHIFT - 1, \
+		BCM2835_TS_TSENSCTL_THOLD_SHIFT)
+#define BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT	18
+#define BCM2835_TS_TSENSCTL_RSTDELAY_BITS	8
+#define BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT	14
+#define BCM2835_TS_TSENSCTL_REGULEN		BIT(26)
+
+#define BCM2835_TS_TSENSSTAT_DATA_BITS		10
+#define BCM2835_TS_TSENSSTAT_DATA_SHIFT		0
+#define BCM2835_TS_TSENSSTAT_DATA_MASK		     \
+	GENMASK(BCM2835_TS_TSENSSTAT_DATA_BITS +     \
+		BCM2835_TS_TSENSSTAT_DATA_SHIFT - 1, \
+		BCM2835_TS_TSENSSTAT_DATA_SHIFT)
+#define BCM2835_TS_TSENSSTAT_VALID		BIT(10)
+#define BCM2835_TS_TSENSSTAT_INTERRUPT		BIT(11)
+
+struct bcm2835_thermal_info {
+	int offset;
+	int slope;
+	int trip_temp;
+};
+
+struct bcm2835_thermal_data {
+	const struct bcm2835_thermal_info *info;
+	void __iomem *regs;
+	struct clk *clk;
+	struct dentry *debugfsdir;
+};
+
+static int bcm2835_thermal_adc2temp(
+	const struct bcm2835_thermal_info *info, u32 adc)
+{
+	return info->offset + (adc * info->slope);
+}
+
+static int bcm2835_thermal_temp2adc(
+	const struct bcm2835_thermal_info *info, int temp)
+{
+	temp -= info->offset;
+	temp /= info->slope;
+
+	if (temp < 0)
+		temp = 0;
+	if (temp >= BIT(BCM2835_TS_TSENSSTAT_DATA_BITS))
+		temp = BIT(BCM2835_TS_TSENSSTAT_DATA_BITS) - 1;
+
+	return temp;
+}
+
+static int bcm2835_thermal_get_trip_type(
+	struct thermal_zone_device *tz, int trip,
+	enum thermal_trip_type *type)
+{
+	*type = THERMAL_TRIP_CRITICAL;
+	return 0;
+}
+
+static int bcm2835_thermal_get_trip_temp(
+	struct thermal_zone_device *tz, int trip, int *temp)
+{
+	struct bcm2835_thermal_data *data = tz->devdata;
+	u32 val = readl(data->regs + BCM2835_TS_TSENSCTL);
+
+	/* get the THOLD bits */
+	val &= BCM2835_TS_TSENSCTL_THOLD_MASK;
+	val >>= BCM2835_TS_TSENSCTL_THOLD_SHIFT;
+
+	/* if it is zero then use the info value */
+	if (val)
+		*temp = bcm2835_thermal_adc2temp(data->info, val);
+	else
+		*temp = data->info->trip_temp;
+
+	return 0;
+}
+
+static int bcm2835_thermal_get_temp(struct thermal_zone_device *tz,
+				    int *temp)
+{
+	struct bcm2835_thermal_data *data = tz->devdata;
+	u32 val = readl(data->regs + BCM2835_TS_TSENSSTAT);
+
+	if (!(val & BCM2835_TS_TSENSSTAT_VALID))
+		return -EIO;
+
+	/* mask the relevant bits */
+	val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
+
+	*temp = bcm2835_thermal_adc2temp(data->info, val);
+
+	return 0;
+}
+
+static const struct debugfs_reg32 bcm2835_thermal_regs[] = {
+	{
+		.name = "ctl",
+		.offset = 0
+	},
+	{
+		.name = "stat",
+		.offset = 4
+	}
+};
+
+static void bcm2835_thermal_debugfs(struct platform_device *pdev)
+{
+	struct thermal_zone_device *tz = platform_get_drvdata(pdev);
+	struct bcm2835_thermal_data *data = tz->devdata;
+	struct debugfs_regset32 *regset;
+
+	data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL);
+	if (!data->debugfsdir)
+		return;
+
+	regset = devm_kzalloc(&pdev->dev, sizeof(*regset), GFP_KERNEL);
+	if (!regset)
+		return;
+
+	regset->regs = bcm2835_thermal_regs;
+	regset->nregs = ARRAY_SIZE(bcm2835_thermal_regs);
+	regset->base = data->regs;
+
+	debugfs_create_regset32("regset", S_IRUGO,
+				data->debugfsdir, regset);
+}
+
+static struct thermal_zone_device_ops bcm2835_thermal_ops  = {
+	.get_temp = bcm2835_thermal_get_temp,
+	.get_trip_temp = bcm2835_thermal_get_trip_temp,
+	.get_trip_type = bcm2835_thermal_get_trip_type,
+};
+
+static const struct of_device_id bcm2835_thermal_of_match_table[];
+static int bcm2835_thermal_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct thermal_zone_device *tz;
+	struct bcm2835_thermal_data *data;
+	struct resource *res;
+	int err;
+	u32 val;
+	unsigned long rate;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	match = of_match_device(bcm2835_thermal_of_match_table,
+				&pdev->dev);
+	if (!match)
+		return -EINVAL;
+	data->info = match->data;
+
+	/* get registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->regs)) {
+		err = PTR_ERR(data->regs);
+		dev_err(&pdev->dev, "Could not get registers: %d\n", err);
+		return err;
+	}
+
+	/* get clock */
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(data->clk)) {
+		err = PTR_ERR(data->clk);
+		if (err != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Could not get clk: %d\n", err);
+		return err;
+	}
+
+	/* set up registers if not already done by the fw */
+	val = readl(data->regs + BCM2835_TS_TSENSCTL);
+	if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
+		/* the basic required flags */
+		val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
+		       BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
+		      BCM2835_TS_TSENSCTL_REGULEN;
+
+		/* reset delay */
+		val |= (BCM2835_TS_TSENSCTL_RSTDELAY_DEFAULT <<
+			BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
+
+		/*  trip_adc value from info */
+		val |= bcm2835_thermal_temp2adc(data->info,
+						data->info->trip_temp) <<
+			BCM2835_TS_TSENSCTL_THOLD_SHIFT;
+
+		/* write the value back to the register as 2 steps */
+		writel(val, data->regs + BCM2835_TS_TSENSCTL);
+		val |= BCM2835_TS_TSENSCTL_RSTB;
+		writel(val, data->regs + BCM2835_TS_TSENSCTL);
+	}
+
+	/* enable clock and check rate */
+	clk_prepare_enable(data->clk);
+	rate = clk_get_rate(data->clk);
+	if ((rate < 1920000) || (rate > 5000000)) {
+		dev_warn(&pdev->dev,
+			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range of 1.9 to 5.0 MHz\n",
+			 data->clk, data->clk);
+	}
+
+	/* register it */
+	tz = thermal_zone_device_register("bcm2835_thermal",
+					  1, 0, data,
+					  &bcm2835_thermal_ops,
+					  NULL, 0, 0);
+	if (IS_ERR(tz)) {
+		clk_disable_unprepare(data->clk);
+		err = PTR_ERR(tz);
+		dev_err(&pdev->dev,
+			"Failed to register the thermal device: %d\n",
+			err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, tz);
+
+	bcm2835_thermal_debugfs(pdev);
+
+	return 0;
+}
+
+static int bcm2835_thermal_remove(struct platform_device *pdev)
+{
+	struct thermal_zone_device *tz = platform_get_drvdata(pdev);
+	struct bcm2835_thermal_data *data = tz->devdata;
+
+	debugfs_remove_recursive(data->debugfsdir);
+	thermal_zone_device_unregister(tz);
+
+	return 0;
+}
+
+static const struct of_device_id bcm2835_thermal_of_match_table[] = {
+	{
+		.compatible = "brcm,bcm2835-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			.offset = 407000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{
+		.compatible = "brcm,bcm2836-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			.offset = 407000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{
+		.compatible = "brcm,bcm2837-thermal",
+		.data = &(struct bcm2835_thermal_info) {
+			/* the bcm2837 needs adjustment of +5C */
+			.offset = 407000 + 5000,
+			.slope = -538,
+			.trip_temp = 80000
+		}
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
+
+static struct platform_driver bcm2835_thermal_driver = {
+	.probe = bcm2835_thermal_probe,
+	.remove = bcm2835_thermal_remove,
+	.driver = {
+		.name = "bcm2835_thermal",
+		.of_match_table = bcm2835_thermal_of_match_table,
+	},
+};
+module_platform_driver(bcm2835_thermal_driver);
+
+MODULE_AUTHOR("Martin Sperl");
+MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
+MODULE_LICENSE("GPL");
-- 
2.1.4

Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Eric Anholt]

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kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org writes:

> From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
>
> Add basic thermal driver for bcm2835 SOC.
>
> This driver currently relies on the firmware setting up the
> tsense HW block and does not set it up itself.
>
> Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
>
> ChangeLog:
>  V1 -> V2: added specific settings depending on compatiblity
> 	   added trip point based on register
> 	   setting up ctrl-register if HW is not enabled by firmware
> 	     as per recommendation of Eric (untested)
> 	   check that clock frequency is in range
> 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> ---

> diff --git a/drivers/thermal/bcm/Makefile b/drivers/thermal/bcm/Makefile
> new file mode 100644
> index 0000000..13456d2
> --- /dev/null
> +++ b/drivers/thermal/bcm/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_BCM2835_THERMAL)		:= bcm2835_thermal.o
> diff --git a/drivers/thermal/bcm/bcm2835_thermal.c b/drivers/thermal/bcm/bcm2835_thermal.c
> new file mode 100644
> index 0000000..73138cb
> --- /dev/null
> +++ b/drivers/thermal/bcm/bcm2835_thermal.c

> +static const struct of_device_id bcm2835_thermal_of_match_table[];
> +static int bcm2835_thermal_probe(struct platform_device *pdev)
> +{

> +	/* enable clock and check rate */
> +	clk_prepare_enable(data->clk);
> +	rate = clk_get_rate(data->clk);
> +	if ((rate < 1920000) || (rate > 5000000)) {
> +		dev_warn(&pdev->dev,
> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range of 1.9 to 5.0 MHz\n",
> +			 data->clk, data->clk);
> +	}
> +
> +	/* register it */
> +	tz = thermal_zone_device_register("bcm2835_thermal",
> +					  1, 0, data,
> +					  &bcm2835_thermal_ops,
> +					  NULL, 0, 0);

I notice that the polling_delay is set to 0, but we're not using
interrupts to trigger the trip.  Is it valid to expose a trip without a
polling_delay or interrupts?  Should passive_delay be set as well?

This is up to the thermal maintainers.  As far as I'm concerned, it's:

Acked-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>

One it lands I'll pull the defconfig and DT bits.

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Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Eric Anholt]

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Eric Anholt <eric@anholt.net> writes:

> kernel@martin.sperl.org writes:
>
>> From: Martin Sperl <kernel@martin.sperl.org>
>>
>> Add basic thermal driver for bcm2835 SOC.
>>
>> This driver currently relies on the firmware setting up the
>> tsense HW block and does not set it up itself.
>>
>> Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
>>
>> ChangeLog:
>>  V1 -> V2: added specific settings depending on compatiblity
>> 	   added trip point based on register
>> 	   setting up ctrl-register if HW is not enabled by firmware
>> 	     as per recommendation of Eric (untested)
>> 	   check that clock frequency is in range
>> 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
>> ---
>
>> diff --git a/drivers/thermal/bcm/Makefile b/drivers/thermal/bcm/Makefile
>> new file mode 100644
>> index 0000000..13456d2
>> --- /dev/null
>> +++ b/drivers/thermal/bcm/Makefile
>> @@ -0,0 +1 @@
>> +obj-$(CONFIG_BCM2835_THERMAL)		:= bcm2835_thermal.o
>> diff --git a/drivers/thermal/bcm/bcm2835_thermal.c b/drivers/thermal/bcm/bcm2835_thermal.c
>> new file mode 100644
>> index 0000000..73138cb
>> --- /dev/null
>> +++ b/drivers/thermal/bcm/bcm2835_thermal.c
>
>> +static const struct of_device_id bcm2835_thermal_of_match_table[];
>> +static int bcm2835_thermal_probe(struct platform_device *pdev)
>> +{
>
>> +	/* enable clock and check rate */
>> +	clk_prepare_enable(data->clk);
>> +	rate = clk_get_rate(data->clk);
>> +	if ((rate < 1920000) || (rate > 5000000)) {
>> +		dev_warn(&pdev->dev,
>> +			 "Clock %pCn is running at %pCr Hz, which is outside the recommended range of 1.9 to 5.0 MHz\n",
>> +			 data->clk, data->clk);
>> +	}
>> +
>> +	/* register it */
>> +	tz = thermal_zone_device_register("bcm2835_thermal",
>> +					  1, 0, data,
>> +					  &bcm2835_thermal_ops,
>> +					  NULL, 0, 0);
>
> I notice that the polling_delay is set to 0, but we're not using
> interrupts to trigger the trip.  Is it valid to expose a trip without a
> polling_delay or interrupts?  Should passive_delay be set as well?
>
> This is up to the thermal maintainers.  As far as I'm concerned, it's:
>
> Acked-by: Eric Anholt <eric@anholt.net>
>
> One it lands I'll pull the defconfig and DT bits.

Ping on this question to thermal maintainers.  I'd still love to see
this driver land.

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Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Zhang Rui]

On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
> Eric Anholt <eric@anholt.net> writes:
> 
> > 
> > kernel@martin.sperl.org writes:
> > 
> > > 
> > > From: Martin Sperl <kernel@martin.sperl.org>
> > > 
> > > Add basic thermal driver for bcm2835 SOC.
> > > 
> > > This driver currently relies on the firmware setting up the
> > > tsense HW block and does not set it up itself.
> > > 
> > > Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
> > > 
> > > ChangeLog:
> > >  V1 -> V2: added specific settings depending on compatiblity
> > > 	   added trip point based on register
> > > 	   setting up ctrl-register if HW is not enabled by firmware
> > > 	     as per recommendation of Eric (untested)
> > > 	   check that clock frequency is in range
> > > 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> > > ---
> > > 
> > > diff --git a/drivers/thermal/bcm/Makefile
> > > b/drivers/thermal/bcm/Makefile
> > > new file mode 100644
> > > index 0000000..13456d2
> > > --- /dev/null
> > > +++ b/drivers/thermal/bcm/Makefile
> > > @@ -0,0 +1 @@
> > > +obj-$(CONFIG_BCM2835_THERMAL)		:=
> > > bcm2835_thermal.o
> > > diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
> > > b/drivers/thermal/bcm/bcm2835_thermal.c
> > > new file mode 100644
> > > index 0000000..73138cb
> > > --- /dev/null
> > > +++ b/drivers/thermal/bcm/bcm2835_thermal.c
> > > 
> > > +static const struct of_device_id
> > > bcm2835_thermal_of_match_table[];
> > > +static int bcm2835_thermal_probe(struct platform_device *pdev)
> > > +{
> > > 
> > > +	/* enable clock and check rate */
> > > +	clk_prepare_enable(data->clk);
> > > +	rate = clk_get_rate(data->clk);
> > > +	if ((rate < 1920000) || (rate > 5000000)) {
> > > +		dev_warn(&pdev->dev,
> > > +			 "Clock %pCn is running at %pCr Hz,
> > > which is outside the recommended range of 1.9 to 5.0 MHz\n",
> > > +			 data->clk, data->clk);
> > > +	}
> > > +
> > > +	/* register it */
> > > +	tz = thermal_zone_device_register("bcm2835_thermal",
> > > +					  1, 0, data,
> > > +					  &bcm2835_thermal_ops,
> > > +					  NULL, 0, 0);
> > I notice that the polling_delay is set to 0, but we're not using
> > interrupts to trigger the trip.  Is it valid to expose a trip
> > without a
> > polling_delay or interrupts?  Should passive_delay be set as well?
> > 
> > This is up to the thermal maintainers.  As far as I'm concerned,
> > it's:
> > 
> > Acked-by: Eric Anholt <eric@anholt.net>
> > 
> > One it lands I'll pull the defconfig and DT bits.
> Ping on this question to thermal maintainers.  I'd still love to see
> this driver land.

hmmm, how is this driver supposed to work?
With this patch set, I think the only benefit is that we can get the
temperature and trip point information via thermal sysfs interface, but
kernel thermal control is a no-op here, right?

thanks,
rui

Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Eric Anholt]

[-- Attachment #1: Type: text/plain, Size: 3360 bytes --]

Zhang Rui <rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> writes:

> On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
>> Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org> writes:
>> 
>> > 
>> > kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org writes:
>> > 
>> > > 
>> > > From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
>> > > 
>> > > Add basic thermal driver for bcm2835 SOC.
>> > > 
>> > > This driver currently relies on the firmware setting up the
>> > > tsense HW block and does not set it up itself.
>> > > 
>> > > Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
>> > > 
>> > > ChangeLog:
>> > >  V1 -> V2: added specific settings depending on compatiblity
>> > > 	   added trip point based on register
>> > > 	   setting up ctrl-register if HW is not enabled by firmware
>> > > 	     as per recommendation of Eric (untested)
>> > > 	   check that clock frequency is in range
>> > > 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
>> > > ---
>> > > 
>> > > diff --git a/drivers/thermal/bcm/Makefile
>> > > b/drivers/thermal/bcm/Makefile
>> > > new file mode 100644
>> > > index 0000000..13456d2
>> > > --- /dev/null
>> > > +++ b/drivers/thermal/bcm/Makefile
>> > > @@ -0,0 +1 @@
>> > > +obj-$(CONFIG_BCM2835_THERMAL)		:=
>> > > bcm2835_thermal.o
>> > > diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
>> > > b/drivers/thermal/bcm/bcm2835_thermal.c
>> > > new file mode 100644
>> > > index 0000000..73138cb
>> > > --- /dev/null
>> > > +++ b/drivers/thermal/bcm/bcm2835_thermal.c
>> > > 
>> > > +static const struct of_device_id
>> > > bcm2835_thermal_of_match_table[];
>> > > +static int bcm2835_thermal_probe(struct platform_device *pdev)
>> > > +{
>> > > 
>> > > +	/* enable clock and check rate */
>> > > +	clk_prepare_enable(data->clk);
>> > > +	rate = clk_get_rate(data->clk);
>> > > +	if ((rate < 1920000) || (rate > 5000000)) {
>> > > +		dev_warn(&pdev->dev,
>> > > +			 "Clock %pCn is running at %pCr Hz,
>> > > which is outside the recommended range of 1.9 to 5.0 MHz\n",
>> > > +			 data->clk, data->clk);
>> > > +	}
>> > > +
>> > > +	/* register it */
>> > > +	tz = thermal_zone_device_register("bcm2835_thermal",
>> > > +					  1, 0, data,
>> > > +					  &bcm2835_thermal_ops,
>> > > +					  NULL, 0, 0);
>> > I notice that the polling_delay is set to 0, but we're not using
>> > interrupts to trigger the trip.  Is it valid to expose a trip
>> > without a
>> > polling_delay or interrupts?  Should passive_delay be set as well?
>> > 
>> > This is up to the thermal maintainers.  As far as I'm concerned,
>> > it's:
>> > 
>> > Acked-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>
>> > 
>> > One it lands I'll pull the defconfig and DT bits.
>> Ping on this question to thermal maintainers.  I'd still love to see
>> this driver land.
>
> hmmm, how is this driver supposed to work?
> With this patch set, I think the only benefit is that we can get the
> temperature and trip point information via thermal sysfs interface, but
> kernel thermal control is a no-op here, right?

Yeah.  It seems useful to be able to get the information.  Once we land
this, I hope someone can add interrupt support so that there are actual
trip points.

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Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Zhang Rui]

On 五, 2016-08-19 at 11:59 -0700, Eric Anholt wrote:
> Zhang Rui <rui.zhang@intel.com> writes:
> 
> > 
> > On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
> > > 
> > > Eric Anholt <eric@anholt.net> writes:
> > > 
> > > > 
> > > > 
> > > > kernel@martin.sperl.org writes:
> > > > 
> > > > > 
> > > > > 
> > > > > From: Martin Sperl <kernel@martin.sperl.org>
> > > > > 
> > > > > Add basic thermal driver for bcm2835 SOC.
> > > > > 
> > > > > This driver currently relies on the firmware setting up the
> > > > > tsense HW block and does not set it up itself.
> > > > > 
> > > > > Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
> > > > > 
> > > > > ChangeLog:
> > > > >  V1 -> V2: added specific settings depending on compatiblity
> > > > > 	   added trip point based on register
> > > > > 	   setting up ctrl-register if HW is not enabled by
> > > > > firmware
> > > > > 	     as per recommendation of Eric (untested)
> > > > > 	   check that clock frequency is in range
> > > > > 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> > > > > ---
> > > > > 
> > > > > diff --git a/drivers/thermal/bcm/Makefile
> > > > > b/drivers/thermal/bcm/Makefile
> > > > > new file mode 100644
> > > > > index 0000000..13456d2
> > > > > --- /dev/null
> > > > > +++ b/drivers/thermal/bcm/Makefile
> > > > > @@ -0,0 +1 @@
> > > > > +obj-$(CONFIG_BCM2835_THERMAL)		:=
> > > > > bcm2835_thermal.o
> > > > > diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > new file mode 100644
> > > > > index 0000000..73138cb
> > > > > --- /dev/null
> > > > > +++ b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > 
> > > > > +static const struct of_device_id
> > > > > bcm2835_thermal_of_match_table[];
> > > > > +static int bcm2835_thermal_probe(struct platform_device
> > > > > *pdev)
> > > > > +{
> > > > > 
> > > > > +	/* enable clock and check rate */
> > > > > +	clk_prepare_enable(data->clk);
> > > > > +	rate = clk_get_rate(data->clk);
> > > > > +	if ((rate < 1920000) || (rate > 5000000)) {
> > > > > +		dev_warn(&pdev->dev,
> > > > > +			 "Clock %pCn is running at %pCr Hz,
> > > > > which is outside the recommended range of 1.9 to 5.0 MHz\n",
> > > > > +			 data->clk, data->clk);
> > > > > +	}
> > > > > +
> > > > > +	/* register it */
> > > > > +	tz = thermal_zone_device_register("bcm2835_thermal",
> > > > > +					  1, 0, data,
> > > > > +					  &bcm2835_thermal_o
> > > > > ps,
> > > > > +					  NULL, 0, 0);
> > > > I notice that the polling_delay is set to 0, but we're not
> > > > using
> > > > interrupts to trigger the trip.  Is it valid to expose a trip
> > > > without a
> > > > polling_delay or interrupts?  Should passive_delay be set as
> > > > well?
> > > > 
> > > > This is up to the thermal maintainers.  As far as I'm
> > > > concerned,
> > > > it's:
> > > > 
> > > > Acked-by: Eric Anholt <eric@anholt.net>
> > > > 
> > > > One it lands I'll pull the defconfig and DT bits.
> > > Ping on this question to thermal maintainers.  I'd still love to
> > > see
> > > this driver land.
> > hmmm, how is this driver supposed to work?
> > With this patch set, I think the only benefit is that we can get
> > the
> > temperature and trip point information via thermal sysfs interface,
> > but
> > kernel thermal control is a no-op here, right?
> Yeah.  It seems useful to be able to get the information.  Once we
> land
> this, I hope someone can add interrupt support so that there are
> actual
> trip points.

sounds reasonable to me.
Another question, why you need a separate directory for a single
file, bcm2835_thermal.c?

thanks,
rui

Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Zhang Rui]

On 日, 2016-08-21 at 21:37 +0800, Zhang Rui wrote:
> On 五, 2016-08-19 at 11:59 -0700, Eric Anholt wrote:
> > 
> > Zhang Rui <rui.zhang@intel.com> writes:
> > 
> > > 
> > > 
> > > On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
> > > > 
> > > > 
> > > > Eric Anholt <eric@anholt.net> writes:
> > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > kernel@martin.sperl.org writes:
> > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > From: Martin Sperl <kernel@martin.sperl.org>
> > > > > > 
> > > > > > Add basic thermal driver for bcm2835 SOC.
> > > > > > 
> > > > > > This driver currently relies on the firmware setting up the
> > > > > > tsense HW block and does not set it up itself.
> > > > > > 
> > > > > > Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
> > > > > > 
> > > > > > ChangeLog:
> > > > > >  V1 -> V2: added specific settings depending on
> > > > > > compatiblity
> > > > > > 	   added trip point based on register
> > > > > > 	   setting up ctrl-register if HW is not enabled by
> > > > > > firmware
> > > > > > 	     as per recommendation of Eric (untested)
> > > > > > 	   check that clock frequency is in range
> > > > > > 	     (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> > > > > > ---
> > > > > > 
> > > > > > diff --git a/drivers/thermal/bcm/Makefile
> > > > > > b/drivers/thermal/bcm/Makefile
> > > > > > new file mode 100644
> > > > > > index 0000000..13456d2
> > > > > > --- /dev/null
> > > > > > +++ b/drivers/thermal/bcm/Makefile
> > > > > > @@ -0,0 +1 @@
> > > > > > +obj-$(CONFIG_BCM2835_THERMAL)		:=
> > > > > > bcm2835_thermal.o
> > > > > > diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > new file mode 100644
> > > > > > index 0000000..73138cb
> > > > > > --- /dev/null
> > > > > > +++ b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > 
> > > > > > +static const struct of_device_id
> > > > > > bcm2835_thermal_of_match_table[];
> > > > > > +static int bcm2835_thermal_probe(struct platform_device
> > > > > > *pdev)
> > > > > > +{
> > > > > > 
> > > > > > +	/* enable clock and check rate */
> > > > > > +	clk_prepare_enable(data->clk);
> > > > > > +	rate = clk_get_rate(data->clk);
> > > > > > +	if ((rate < 1920000) || (rate > 5000000)) {
> > > > > > +		dev_warn(&pdev->dev,
> > > > > > +			 "Clock %pCn is running at %pCr
> > > > > > Hz,
> > > > > > which is outside the recommended range of 1.9 to 5.0
> > > > > > MHz\n",
> > > > > > +			 data->clk, data->clk);
> > > > > > +	}
> > > > > > +
> > > > > > +	/* register it */
> > > > > > +	tz =
> > > > > > thermal_zone_device_register("bcm2835_thermal",
> > > > > > +					  1, 0, data,
> > > > > > +					  &bcm2835_thermal
> > > > > > _o
> > > > > > ps,
> > > > > > +					  NULL, 0, 0);
> > > > > I notice that the polling_delay is set to 0, but we're not
> > > > > using
> > > > > interrupts to trigger the trip.  Is it valid to expose a trip
> > > > > without a
> > > > > polling_delay or interrupts?  Should passive_delay be set as
> > > > > well?
> > > > > 
> > > > > This is up to the thermal maintainers.  As far as I'm
> > > > > concerned,
> > > > > it's:
> > > > > 
> > > > > Acked-by: Eric Anholt <eric@anholt.net>
> > > > > 
> > > > > One it lands I'll pull the defconfig and DT bits.
> > > > Ping on this question to thermal maintainers.  I'd still love
> > > > to
> > > > see
> > > > this driver land.
> > > hmmm, how is this driver supposed to work?
> > > With this patch set, I think the only benefit is that we can get
> > > the
> > > temperature and trip point information via thermal sysfs
> > > interface,
> > > but
> > > kernel thermal control is a no-op here, right?
> > Yeah.  It seems useful to be able to get the information.  Once we
> > land
> > this, I hope someone can add interrupt support so that there are
> > actual
> > trip points.
> sounds reasonable to me.
BTW, can you add a "TODO" comment for this gap?

thanks,
rui
> Another question, why you need a separate directory for a single
> file, bcm2835_thermal.c?
> 
> thanks,
> rui
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pm"
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Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Martin Sperl]

> On 21.08.2016, at 15:37, Zhang Rui <rui.zhang@intel.com> wrote:
> 
>> On 五, 2016-08-19 at 11:59 -0700, Eric Anholt wrote:
>> Zhang Rui <rui.zhang@intel.com> writes:
>> 
>>> 
>>>> On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
>>>> 
>>>> Eric Anholt <eric@anholt.net> writes:
>>>> 
>>>>> 
>>>>> 
>>>>> kernel@martin.sperl.org writes:
>>>>> 
>>>>>> 
>>>>>> 
>>>>>> From: Martin Sperl <kernel@martin.sperl.org>
>>>>>> 
>>>>>> Add basic thermal driver for bcm2835 SOC.
>>>>>> 
>>>>>> This driver currently relies on the firmware setting up the
>>>>>> tsense HW block and does not set it up itself.
>>>>>> 
>>>>>> Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
>>>>>> 
>>>>>> ChangeLog:
>>>>>>  V1 -> V2: added specific settings depending on compatiblity
>>>>>>       added trip point based on register
>>>>>>       setting up ctrl-register if HW is not enabled by
>>>>>> firmware
>>>>>>         as per recommendation of Eric (untested)
>>>>>>       check that clock frequency is in range
>>>>>>         (1.9 - 5MHz - as per comment in clk-bcm2835.c)
>>>>>> ---
>>>>>> 
>>>>>> diff --git a/drivers/thermal/bcm/Makefile
>>>>>> b/drivers/thermal/bcm/Makefile
>>>>>> new file mode 100644
>>>>>> index 0000000..13456d2
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/thermal/bcm/Makefile
>>>>>> @@ -0,0 +1 @@
>>>>>> +obj-$(CONFIG_BCM2835_THERMAL)        :=
>>>>>> bcm2835_thermal.o
>>>>>> diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
>>>>>> b/drivers/thermal/bcm/bcm2835_thermal.c
>>>>>> new file mode 100644
>>>>>> index 0000000..73138cb
>>>>>> --- /dev/null
>>>>>> +++ b/drivers/thermal/bcm/bcm2835_thermal.c
>>>>>> 
>>>>>> +static const struct of_device_id
>>>>>> bcm2835_thermal_of_match_table[];
>>>>>> +static int bcm2835_thermal_probe(struct platform_device
>>>>>> *pdev)
>>>>>> +{
>>>>>> 
>>>>>> +    /* enable clock and check rate */
>>>>>> +    clk_prepare_enable(data->clk);
>>>>>> +    rate = clk_get_rate(data->clk);
>>>>>> +    if ((rate < 1920000) || (rate > 5000000)) {
>>>>>> +        dev_warn(&pdev->dev,
>>>>>> +             "Clock %pCn is running at %pCr Hz,
>>>>>> which is outside the recommended range of 1.9 to 5.0 MHz\n",
>>>>>> +             data->clk, data->clk);
>>>>>> +    }
>>>>>> +
>>>>>> +    /* register it */
>>>>>> +    tz = thermal_zone_device_register("bcm2835_thermal",
>>>>>> +                      1, 0, data,
>>>>>> +                      &bcm2835_thermal_o
>>>>>> ps,
>>>>>> +                      NULL, 0, 0);
>>>>> I notice that the polling_delay is set to 0, but we're not
>>>>> using
>>>>> interrupts to trigger the trip.  Is it valid to expose a trip
>>>>> without a
>>>>> polling_delay or interrupts?  Should passive_delay be set as
>>>>> well?
>>>>> 
>>>>> This is up to the thermal maintainers.  As far as I'm
>>>>> concerned,
>>>>> it's:
>>>>> 
>>>>> Acked-by: Eric Anholt <eric@anholt.net>
>>>>> 
>>>>> One it lands I'll pull the defconfig and DT bits.
>>>> Ping on this question to thermal maintainers.  I'd still love to
>>>> see
>>>> this driver land.
>>> hmmm, how is this driver supposed to work?
>>> With this patch set, I think the only benefit is that we can get
>>> the
>>> temperature and trip point information via thermal sysfs interface,
>>> but
>>> kernel thermal control is a no-op here, right?
>> Yeah.  It seems useful to be able to get the information.  Once we
>> land
>> this, I hope someone can add interrupt support so that there are
>> actual
>> trip points.
> 
> sounds reasonable to me.
> Another question, why you need a separate directory for a single
> file, bcm2835_thermal.c?

Lots of other subsystems (clk, sound/soc, ...) are using vendor specific
sub directories.
In thermal there are already subdirectories for Samsung or st.
So this was done in this case as well to support Broadcom immediately
following this pattern.

You want a new version to keep it in thermal directly I can create a
new version of the patch.

Thanks, Martin

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Re: [PATCH V3 2/5] thermal: bcm2835: add thermal driver for bcm2835 soc

[Zhang Rui]

On 日, 2016-08-21 at 19:21 +0200, Martin Sperl wrote:
> > 
> > On 21.08.2016, at 15:37, Zhang Rui <rui.zhang@intel.com> wrote:
> > 
> > > 
> > > On 五, 2016-08-19 at 11:59 -0700, Eric Anholt wrote:
> > > Zhang Rui <rui.zhang@intel.com> writes:
> > > 
> > > > 
> > > > 
> > > > > 
> > > > > On 四, 2016-08-18 at 11:39 -0700, Eric Anholt wrote:
> > > > > 
> > > > > Eric Anholt <eric@anholt.net> writes:
> > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > kernel@martin.sperl.org writes:
> > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > 
> > > > > > > From: Martin Sperl <kernel@martin.sperl.org>
> > > > > > > 
> > > > > > > Add basic thermal driver for bcm2835 SOC.
> > > > > > > 
> > > > > > > This driver currently relies on the firmware setting up
> > > > > > > the
> > > > > > > tsense HW block and does not set it up itself.
> > > > > > > 
> > > > > > > Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
> > > > > > > 
> > > > > > > ChangeLog:
> > > > > > >  V1 -> V2: added specific settings depending on
> > > > > > > compatiblity
> > > > > > >       added trip point based on register
> > > > > > >       setting up ctrl-register if HW is not enabled by
> > > > > > > firmware
> > > > > > >         as per recommendation of Eric (untested)
> > > > > > >       check that clock frequency is in range
> > > > > > >         (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> > > > > > > ---
> > > > > > > 
> > > > > > > diff --git a/drivers/thermal/bcm/Makefile
> > > > > > > b/drivers/thermal/bcm/Makefile
> > > > > > > new file mode 100644
> > > > > > > index 0000000..13456d2
> > > > > > > --- /dev/null
> > > > > > > +++ b/drivers/thermal/bcm/Makefile
> > > > > > > @@ -0,0 +1 @@
> > > > > > > +obj-$(CONFIG_BCM2835_THERMAL)        :=
> > > > > > > bcm2835_thermal.o
> > > > > > > diff --git a/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > > b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > > new file mode 100644
> > > > > > > index 0000000..73138cb
> > > > > > > --- /dev/null
> > > > > > > +++ b/drivers/thermal/bcm/bcm2835_thermal.c
> > > > > > > 
> > > > > > > +static const struct of_device_id
> > > > > > > bcm2835_thermal_of_match_table[];
> > > > > > > +static int bcm2835_thermal_probe(struct platform_device
> > > > > > > *pdev)
> > > > > > > +{
> > > > > > > 
> > > > > > > +    /* enable clock and check rate */
> > > > > > > +    clk_prepare_enable(data->clk);
> > > > > > > +    rate = clk_get_rate(data->clk);
> > > > > > > +    if ((rate < 1920000) || (rate > 5000000)) {
> > > > > > > +        dev_warn(&pdev->dev,
> > > > > > > +             "Clock %pCn is running at %pCr Hz,
> > > > > > > which is outside the recommended range of 1.9 to 5.0
> > > > > > > MHz\n",
> > > > > > > +             data->clk, data->clk);
> > > > > > > +    }
> > > > > > > +
> > > > > > > +    /* register it */
> > > > > > > +    tz = thermal_zone_device_register("bcm2835_thermal",
> > > > > > > +                      1, 0, data,
> > > > > > > +                      &bcm2835_thermal_o
> > > > > > > ps,
> > > > > > > +                      NULL, 0, 0);
> > > > > > I notice that the polling_delay is set to 0, but we're not
> > > > > > using
> > > > > > interrupts to trigger the trip.  Is it valid to expose a
> > > > > > trip
> > > > > > without a
> > > > > > polling_delay or interrupts?  Should passive_delay be set
> > > > > > as
> > > > > > well?
> > > > > > 
> > > > > > This is up to the thermal maintainers.  As far as I'm
> > > > > > concerned,
> > > > > > it's:
> > > > > > 
> > > > > > Acked-by: Eric Anholt <eric@anholt.net>
> > > > > > 
> > > > > > One it lands I'll pull the defconfig and DT bits.
> > > > > Ping on this question to thermal maintainers.  I'd still love
> > > > > to
> > > > > see
> > > > > this driver land.
> > > > hmmm, how is this driver supposed to work?
> > > > With this patch set, I think the only benefit is that we can
> > > > get
> > > > the
> > > > temperature and trip point information via thermal sysfs
> > > > interface,
> > > > but
> > > > kernel thermal control is a no-op here, right?
> > > Yeah.  It seems useful to be able to get the information.  Once
> > > we
> > > land
> > > this, I hope someone can add interrupt support so that there are
> > > actual
> > > trip points.
> > sounds reasonable to me.
> > Another question, why you need a separate directory for a single
> > file, bcm2835_thermal.c?
> Lots of other subsystems (clk, sound/soc, ...) are using vendor
> specific
> sub directories.
> In thermal there are already subdirectories for Samsung or st.
> So this was done in this case as well to support Broadcom immediately
> following this pattern.
> 
> You want a new version to keep it in thermal directly I can create a
> new version of the patch.
> 
If there are more broadcom patches coming, in your plan, it's okay to
have its own subdirectory. Or else, it's better to create the
subdirectory when it's actually needed.

thanks,
rui
> Thanks, Martin

[PATCH V3 3/5] ARM: bcm2835: add thermal node to device-tree of bcm283x

[kernel-TqfNSX0MhmxHKSADF0wUEw]

From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>

Add the node for the thermal sensor of the bcm2835-soc
to the device tree.

Signed-off-by: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
Reviewed-by: Eric Anholt <eric-WhKQ6XTQaPysTnJN9+BGXg@public.gmane.org>
---
 arch/arm/boot/dts/bcm283x.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index 37b35eb..6f6949b 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -153,6 +153,12 @@
 			status = "disabled";
 		};
 
+		thermal: thermal@0x7e212000 {
+			compatible = "brcm,bcm2835-thermal";
+			reg = <0x7e212000 0x8>;
+			clocks = <&clocks BCM2835_CLOCK_TSENS>;
+		};
+
 		aux: aux@0x7e215000 {
 			compatible = "brcm,bcm2835-aux";
 			#clock-cells = <1>;
-- 
2.1.4

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[PATCH V3 4/5] ARM: bcm2835: add thermal driver to default_config

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add the thermal driver to list of compiled modules
in the default config for bcm2835.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
---
 arch/arm/configs/bcm2835_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig
index 29a44bd..634e07e 100644
--- a/arch/arm/configs/bcm2835_defconfig
+++ b/arch/arm/configs/bcm2835_defconfig
@@ -71,6 +71,8 @@ CONFIG_SPI_BCM2835=y
 CONFIG_SPI_BCM2835AUX=y
 CONFIG_GPIO_SYSFS=y
 # CONFIG_HWMON is not set
+CONFIG_THERMAL=y
+CONFIG_BCM2835_THERMAL=y
 CONFIG_WATCHDOG=y
 CONFIG_BCM2835_WDT=y
 CONFIG_FB=y
-- 
2.1.4

[PATCH V3 5/5] ARM: multi_v7_defconfig: bcm2835: add bcm2835-thermal driver

[kernel]

From: Martin Sperl <kernel@martin.sperl.org>

Add the thermal driver to list of compiled modules in
multi_v7_defconfig.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>

Changelog:
 V1 -> V2: added this patch
 V2 -> V3: made driver compile as a module not in-kernel
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 1e799fe..bd6d400 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -422,6 +422,7 @@ CONFIG_CPU_THERMAL=y
 CONFIG_ROCKCHIP_THERMAL=y
 CONFIG_RCAR_THERMAL=y
 CONFIG_ARMADA_THERMAL=y
+CONFIG_BCM2835_THERMAL=m
 CONFIG_DAVINCI_WATCHDOG=m
 CONFIG_EXYNOS_THERMAL=m
 CONFIG_ST_THERMAL_SYSCFG=y
--
2.1.4