[PATCH v4 0/4] thermal: Add support of multiple sensors

[PATCH v4 0/4] thermal: Add support of multiple sensors

[Alexandre Bailon]

Following this comment [1], this updates thermal_of to support multiple
sensors.

This series intends to add support of thermal aggregation.
One use case for it is using the IPA in the case we have
multiple sensors for one performance domain.

This has been tested on the mt8195 using s-tui.
To test and validate, we heat up the CPU and the heat sink.
At some point, we run benchmark tests with different configurations:
- Mediatek kernel (IPA + their own thermal aggregation)
- Mainline kernel
- Mainline kernel with IPA and aggregation enabled
With the IPA and the aggregation enabled, we get the best performances
with the most stable CPU temperature.

The aggregation is configured and enabled using device tree.
One thermal zone has to be created with a list of sensors.
It will take care of registering a thermal zone for each sensors.
The cooling device will only be registered with the aggregating thermal
zone.

There are still something important missing: a way to check that all
aggregated sensors are part of the same performance domain.
So far, I don't see how this should be done. Some recommendations would be
appreciated.

Changes in v2:
- Rebased on 6.7
- Separated generic multi sensor and dt specific code
- Simplified the code
- Drop min / max and only do weighted average (seems more adequate for IPA)

Changes in v3:
- Rebased on 6.9
- Reworked the way to register a multi sensor thermal zone
  - Only one thermal zone to define in device tree
- Max has been re-added
- Enabled it on mt8195

Changes in v4:
- Rebased on lastest master (fixed the build issue)
- Dropped the average since I don't have any usecase for it

[1]: https://patchwork.kernel.org/comment/24723927/

Alexandre Bailon (4):
  dt-bindings: thermal: Restore the thermal-sensors property
  thermal: Add support of multi sensors to thermal_core
  thermal: Add support of multi sensors to thermal_of
  ARM64: mt8195: Use thermal aggregation for big and little cpu

 .../bindings/thermal/thermal-zones.yaml       |   5 +-
 arch/arm64/boot/dts/mediatek/mt8195.dtsi      | 212 ++-----------
 drivers/thermal/Makefile                      |   1 +
 drivers/thermal/thermal_core.h                |  15 +
 drivers/thermal/thermal_multi.c               | 288 ++++++++++++++++++
 drivers/thermal/thermal_of.c                  | 250 ++++++++++++++-
 include/uapi/linux/thermal.h                  |   5 +
 7 files changed, 579 insertions(+), 197 deletions(-)
 create mode 100644 drivers/thermal/thermal_multi.c

-- 
2.44.1

[PATCH v4 1/4] dt-bindings: thermal: Restore the thermal-sensors property

[Alexandre Bailon]

thermal-sensors was defined in thermal.txt but when the yaml binding
has been defined, its definition has changed, dropping support of multi
sensors.
Since we are adding support of multi sensors, use the original definition
for thermal-sensors property.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/thermal/thermal-zones.yaml | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
index 68398e7e8655..fa7a72e2ba44 100644
--- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
+++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
@@ -93,10 +93,9 @@ patternProperties:
 
       thermal-sensors:
         $ref: /schemas/types.yaml#/definitions/phandle-array
-        maxItems: 1
         description:
-          The thermal sensor phandle and sensor specifier used to monitor this
-          thermal zone.
+          A list of thermal sensor phandles and sensor specifier
+          used while monitoring the thermal zone.
 
       coefficients:
         $ref: /schemas/types.yaml#/definitions/uint32-array
-- 
2.44.1

[PATCH v4 2/4] thermal: Add support of multi sensors to thermal_core

[Alexandre Bailon]

This adds support of multi sensors to thermal.
Currently, this only support the get_temp operation.
This returns the maximum temperature among all the sensors.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
---
 drivers/thermal/Makefile        |   1 +
 drivers/thermal/thermal_core.h  |  15 ++
 drivers/thermal/thermal_multi.c | 286 ++++++++++++++++++++++++++++++++
 include/uapi/linux/thermal.h    |   5 +
 4 files changed, 307 insertions(+)
 create mode 100644 drivers/thermal/thermal_multi.c

diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 5cdf7d68687f..872190f9062b 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -6,6 +6,7 @@ CFLAGS_thermal_core.o		:= -I$(src)
 obj-$(CONFIG_THERMAL)		+= thermal_sys.o
 thermal_sys-y			+= thermal_core.o thermal_sysfs.o
 thermal_sys-y			+= thermal_trip.o thermal_helpers.o
+thermal_sys-y			+= thermal_multi.o
 
 # netlink interface to manage the thermal framework
 thermal_sys-$(CONFIG_THERMAL_NETLINK)		+= thermal_netlink.o
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 20e7b45673d6..c2cf2c19738a 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -261,6 +261,21 @@ ssize_t weight_show(struct device *, struct device_attribute *, char *);
 ssize_t weight_store(struct device *, struct device_attribute *, const char *,
 		     size_t);
 
+/* Multi sensors */
+struct thermal_zone_device *thermal_multi_sensor_find_tz(const char *type);
+struct thermal_zone_device_ops *thermal_multi_sensor_alloc_ops(void);
+struct thermal_zone_device *thermal_multi_sensor_tz_alloc(const char *type,
+						  struct thermal_trip *trips,
+						  int num_trips,
+						  struct thermal_zone_device_ops *ops,
+						  int passive_delay, int polling_delay);
+void thermal_multi_sensor_tz_free(struct thermal_zone_device *tz);
+int thermal_multi_sensor_validate_coeff(int *coeff, int count, int offset);
+int thermal_multi_sensor_register(struct thermal_zone_device *tz,
+	struct thermal_zone_device *sensor_tz, int coeff);
+void thermal_multi_sensor_unregister(struct thermal_zone_device *sensor_tz);
+
+
 #ifdef CONFIG_THERMAL_STATISTICS
 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
 					 unsigned long new_state);
diff --git a/drivers/thermal/thermal_multi.c b/drivers/thermal/thermal_multi.c
new file mode 100644
index 000000000000..4b3f261a7000
--- /dev/null
+++ b/drivers/thermal/thermal_multi.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+#include <linux/types.h>
+#include <linux/string.h>
+
+#include "thermal_core.h"
+
+struct sensor_interface {
+	struct thermal_zone_device *tz;
+	int coeff;
+
+	struct list_head node;
+};
+
+struct multi_sensor_thermal_zone {
+	struct thermal_zone_device *tz;
+	struct mutex sensors_lock;
+	struct list_head sensors;
+
+	struct list_head node;
+};
+
+static DEFINE_MUTEX(multi_tz_mutex);
+static LIST_HEAD(multi_tz_list);
+
+#define TJ_MAX 120000
+
+static int multi_sensor_get_temp_max(struct thermal_zone_device *tz, int *temp)
+{
+	struct multi_sensor_thermal_zone *multi_tz = tz->devdata;
+	struct sensor_interface *sensor;
+	int max_temp;
+	int ret;
+
+	mutex_lock(&multi_tz->sensors_lock);
+
+	if (list_empty(&multi_tz->sensors)) {
+		mutex_unlock(&multi_tz->sensors_lock);
+		return -ENODEV;
+	}
+
+	list_for_each_entry(sensor, &multi_tz->sensors, node) {
+		ret = thermal_zone_get_temp(sensor->tz, temp);
+		if (ret) {
+			mutex_unlock(&multi_tz->sensors_lock);
+			return ret;
+		}
+
+		max_temp = max(max_temp, *temp * sensor->coeff);
+	}
+
+	mutex_unlock(&multi_tz->sensors_lock);
+
+	*temp = max_temp;
+	return ret;
+}
+
+/**
+ * Check if the sum of the coefficients multiplied by sensors temperature plus
+ * an offset won't overflow during the aggregation.
+ * @coeff: An array of coefficient
+ * @count: Number of coefficient
+ * @offset: The offset
+ *
+ * Returns: 0 if the coefficient are safe, -EOVERFLOW otherwise
+ */
+int thermal_multi_sensor_validate_coeff(int *coeff, int count, int offset)
+{
+	int max_accumulated_temp = 0;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		max_accumulated_temp += TJ_MAX * coeff[i];
+		if (max_accumulated_temp < 0)
+			return -EOVERFLOW;
+	}
+
+	max_accumulated_temp += offset;
+	return max_accumulated_temp < 0 ? -EOVERFLOW : 0;
+}
+
+/**
+ * Find a multi sensor thermal zone
+ * @type: The thermal zone type to find
+ *
+ * Returns: a pointer to the thermal zone or NULL  if not found
+ */
+struct thermal_zone_device *thermal_multi_sensor_find_tz(const char *type)
+{
+	struct thermal_zone_device *tz;
+
+	tz = thermal_zone_get_zone_by_name(type);
+	if (IS_ERR(tz))
+		return NULL;
+	return tz;
+}
+
+/**
+ * Allocate a struct thermal_zone_device_ops for the multi sensor thermal zoen
+ *
+ * This allocates a struct thermal_zone_device_ops with a predifiend get_temp
+ * operation. This allows setting the other function pointers before registering
+ * the thermal zone.
+ *
+ * Returns: a pointer to the created struct thermal_zone_device_ops or an
+ * in case of error, an ERR_PTR. Caller must check return value with
+ * IS_ERR*() helpers.
+ */
+struct thermal_zone_device_ops *thermal_multi_sensor_alloc_ops(void)
+{
+	struct thermal_zone_device_ops *ops;
+
+	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+	if (!ops)
+		return ERR_PTR(-ENOMEM);
+
+	ops->get_temp = multi_sensor_get_temp_max;
+
+	return ops;
+}
+
+/**
+ * Register a new thermal zone device that supports multi sensors
+ * @type:	the thermal zone device type
+ * @trips:	a pointer to an array of thermal trips
+ * @num_trips:	the number of trip points the thermal zone support
+ * @mask:	a bit string indicating the writeablility of trip points
+ * @ops:	standard thermal zone device callbacks
+ * @passive_delay: number of milliseconds to wait between polls when
+ *		   performing passive cooling
+ * @polling_delay: number of milliseconds to wait between polls when checking
+ *		   whether trip points have been crossed (0 for interrupt
+ *		   driven systems)
+ *
+ * This function allocates and register a multi sensor thermal zone.
+ * To register a sensor to this thermal zone, use thermal_multi_sensor_register().
+ * thermal_multi_sensor_unregister() must be called to unregister the sensors
+ * and release this thermal zone when it is not used anymore.
+ *
+ * Return: a pointer to the created struct thermal_zone_device or an
+ * in case of error, an ERR_PTR. Caller must check return value with
+ * IS_ERR*() helpers.
+ */
+struct thermal_zone_device *thermal_multi_sensor_tz_alloc(const char *type,
+					struct thermal_trip *trips,
+					int num_trips,
+					struct thermal_zone_device_ops *ops,
+					int passive_delay, int polling_delay)
+{
+	struct thermal_zone_device *tz;
+	struct thermal_zone_params tzp = {};
+	struct multi_sensor_thermal_zone *multi_tz;
+
+	mutex_lock(&multi_tz_mutex);
+
+	tz = thermal_zone_get_zone_by_name(type);
+	if (!IS_ERR(tz))
+		goto unlock;
+
+	multi_tz = kzalloc(sizeof(*multi_tz), GFP_KERNEL);
+	if (!multi_tz) {
+		tz = ERR_PTR(-ENOMEM);
+		goto unlock;
+	}
+	mutex_init(&multi_tz->sensors_lock);
+	INIT_LIST_HEAD(&multi_tz->sensors);
+
+	tzp.no_hwmon = true;
+	tzp.slope = 1;
+	tzp.offset = 0;
+
+	tz = thermal_zone_device_register_with_trips(type, trips, num_trips,
+						     multi_tz, ops, &tzp,
+						     passive_delay, polling_delay);
+	if (IS_ERR(tz)) {
+		kfree(multi_tz);
+	} else {
+		multi_tz->tz = tz;
+		list_add(&multi_tz->node, &multi_tz_list);
+	}
+
+unlock:
+	mutex_unlock(&multi_tz_mutex);
+	return tz;
+}
+
+/**
+ * Remove all sensors from multi sensor thermal zone and release it
+ *
+ * This function must not be used except on error path to correctly
+ * release all the allocated resources.
+ * Use thermal_multi_sensor_unregister() to unregister a sensor and
+ * release a thermal zone that is not used anymore.
+ *
+ * @tz: Pointer to thermal zone to release
+ */
+void thermal_multi_sensor_tz_free(struct thermal_zone_device *tz)
+{
+	struct multi_sensor_thermal_zone *multi_tz = tz->devdata;
+	struct thermal_zone_device_ops *ops = &tz->ops;
+	struct sensor_interface *sensor, *tmp;
+
+	list_for_each_entry_safe(sensor, tmp, &multi_tz->sensors, node) {
+		list_del(&sensor->node);
+		kfree(sensor);
+	}
+
+	thermal_zone_device_unregister(tz);
+	list_del(&multi_tz->node);
+	kfree(multi_tz);
+	kfree(ops);
+}
+
+/**
+ * Register a thermal sensor to a multi sensor thermal zone
+ * @tz: The multi sensor thermal zone
+ * @sensor_tz: The thermal zone of the zensor to register
+ * @coeff: The coefficient to apply to the temperature returned by the sensor
+ *
+ * Returns: On success 0, a negative value in case of error
+ */
+int thermal_multi_sensor_register(struct thermal_zone_device *tz,
+				  struct thermal_zone_device *sensor_tz,
+				  int coeff)
+{
+	struct multi_sensor_thermal_zone *multi_tz;
+	struct sensor_interface *sensor;
+
+	mutex_lock(&multi_tz_mutex);
+
+	multi_tz =  tz->devdata;
+
+	sensor = kzalloc(sizeof(*sensor), GFP_KERNEL);
+	if (!sensor) {
+		mutex_unlock(&multi_tz_mutex);
+		return -ENOMEM;
+	}
+
+	sensor->tz = sensor_tz;
+	sensor->coeff = coeff;
+	mutex_lock(&multi_tz->sensors_lock);
+	list_add(&sensor->node, &multi_tz->sensors);
+	mutex_unlock(&multi_tz->sensors_lock);
+
+	thermal_zone_device_enable(tz);
+
+	mutex_unlock(&multi_tz_mutex);
+
+	return 0;
+}
+
+/**
+ * Unregister a thermal sensor from a multi sensor thermal zone
+ *
+ * This unregister a thermal sensor from a multi sensor thermal zone.
+ * If all the sensors have been removed then this also release the multi sensor
+ * thermal zone.
+ * @sensor_tz: The sensor to unregister
+ */
+void thermal_multi_sensor_unregister(struct thermal_zone_device *sensor_tz)
+{
+	struct multi_sensor_thermal_zone *multi_tz, *tmp_tz;
+	struct sensor_interface *sensor, *tmp;
+
+	mutex_lock(&multi_tz_mutex);
+	list_for_each_entry_safe(multi_tz, tmp_tz, &multi_tz_list, node) {
+		mutex_lock(&multi_tz->sensors_lock);
+		list_for_each_entry_safe(sensor, tmp, &multi_tz->sensors, node) {
+			if (sensor->tz == sensor_tz) {
+				list_del(&sensor->node);
+				kfree(sensor);
+				break;
+			}
+		}
+		mutex_unlock(&multi_tz->sensors_lock);
+
+		if (list_empty(&multi_tz->sensors))
+			thermal_multi_sensor_tz_free(multi_tz->tz);
+	}
+	mutex_unlock(&multi_tz_mutex);
+}
diff --git a/include/uapi/linux/thermal.h b/include/uapi/linux/thermal.h
index fc78bf3aead7..e4f6c4c5e6fd 100644
--- a/include/uapi/linux/thermal.h
+++ b/include/uapi/linux/thermal.h
@@ -16,6 +16,11 @@ enum thermal_trip_type {
 	THERMAL_TRIP_CRITICAL,
 };
 
+enum thermal_aggregation_type {
+	THERMAL_AGGR_AVG = 0,
+	THERMAL_AGGR_MAX = 1,
+};
+
 /* Adding event notification support elements */
 #define THERMAL_GENL_FAMILY_NAME		"thermal"
 #define THERMAL_GENL_VERSION			0x01
-- 
2.44.1

[PATCH v4 3/4] thermal: Add support of multi sensors to thermal_of

[Alexandre Bailon]

This updates thermal_of to support more than one sensor.
If during the registration we find another thermal zone referencing
this sensors and some other, then we create the multi sensor thermal
zone (if it doesn't exist) and register the sensor to it.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
---
 drivers/thermal/thermal_of.c | 250 +++++++++++++++++++++++++++++++++--
 1 file changed, 241 insertions(+), 9 deletions(-)

diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
index aa34b6e82e26..fef966557b30 100644
--- a/drivers/thermal/thermal_of.c
+++ b/drivers/thermal/thermal_of.c
@@ -18,6 +18,8 @@
 
 #include "thermal_core.h"
 
+#define STRLEN_ID (8)
+
 /***   functions parsing device tree nodes   ***/
 
 static int of_find_trip_id(struct device_node *np, struct device_node *trip)
@@ -222,6 +224,77 @@ static struct device_node *of_thermal_zone_find(struct device_node *sensor, int
 	return tz;
 }
 
+static int thermal_of_multi_sensor_get_name(struct device_node *sensor, int id,
+					    struct device_node *tz, char *name)
+{
+	struct of_phandle_args sensor_specs;
+	int count, i;
+
+	tz = of_thermal_zone_find(sensor, id);
+	if (!tz) {
+		pr_debug("No thermal zones description\n");
+		return -ENODEV;
+	}
+
+	count = of_count_phandle_with_args(tz, "thermal-sensors",
+						"#thermal-sensor-cells");
+	if (count <= 0)
+		return count;
+
+	for (i = 0; i < count; i++) {
+
+		int ret;
+
+		ret = of_parse_phandle_with_args(tz, "thermal-sensors",
+							"#thermal-sensor-cells",
+							i, &sensor_specs);
+		if (ret < 0) {
+			pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
+			return ret;
+		}
+
+		if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
+								sensor_specs.args[0] : 0)) {
+			snprintf(name, THERMAL_NAME_LENGTH, "%s%d", tz->name, id);
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+static int thermal_of_multi_sensor_get_id(struct device_node *sensor,
+					 struct device_node *tz, int id)
+{
+	struct of_phandle_args sensor_specs;
+	int count, i;
+
+	count = of_count_phandle_with_args(tz, "thermal-sensors",
+						"#thermal-sensor-cells");
+	if (count <= 0)
+		return 0;
+
+	for (i = 0; i < count; i++) {
+
+		int ret;
+
+		ret = of_parse_phandle_with_args(tz, "thermal-sensors",
+							"#thermal-sensor-cells",
+							i, &sensor_specs);
+		if (ret < 0) {
+			pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
+			return 0;
+		}
+
+		if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
+								sensor_specs.args[0] : 0)) {
+			return i;
+		}
+	}
+
+	return -ENODEV;
+}
+
 static int thermal_of_monitor_init(struct device_node *np, int *delay, int *pdelay)
 {
 	int ret;
@@ -281,6 +354,17 @@ static struct device_node *thermal_of_zone_get_by_name(struct thermal_zone_devic
 		return ERR_PTR(-ENODEV);
 
 	tz_np = of_get_child_by_name(np, tz->type);
+	if (!tz_np) {
+		char tmp[THERMAL_NAME_LENGTH];
+		char *ptr;
+
+		ptr = strrchr(tz->type, '.');
+		if (!ptr)
+			return ERR_PTR(-ENODEV);
+
+		strscpy(tmp, tz->type, (ptr - tz->type) + 1);
+		tz_np = of_get_child_by_name(np, tmp);
+	}
 
 	of_node_put(np);
 
@@ -444,10 +528,140 @@ static int thermal_of_unbind(struct thermal_zone_device *tz,
  */
 static void thermal_of_zone_unregister(struct thermal_zone_device *tz)
 {
+	thermal_multi_sensor_unregister(tz);
 	thermal_zone_device_disable(tz);
 	thermal_zone_device_unregister(tz);
 }
 
+static int thermal_of_multi_sensor_validate_coeff(struct device_node *sensor, int id,
+						  struct device_node *tz_np)
+{
+	u32 *coeff;
+	int ret;
+	int i;
+
+	int count;
+	int index;
+	int offset;
+
+	index = thermal_of_multi_sensor_get_id(sensor, tz_np, id);
+	if (index < 0)
+		return -ENODEV;
+
+
+	count = of_count_phandle_with_args(tz_np,
+					   "thermal-sensors",
+					   "#thermal-sensor-cells");
+	if (count < 0)
+		return count;
+
+	coeff = kmalloc_array(count, sizeof(*coeff), GFP_KERNEL);
+	if (!coeff)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		ret = of_property_read_u32_index(tz_np,
+						 "coefficients",
+						 i, coeff + i);
+		if (ret)
+			coeff[i] = 1;
+	}
+
+	ret = of_property_read_u32_index(tz_np, "coefficients",
+					 count, &offset);
+	if (ret)
+		offset = 0;
+
+	/* Make sure the coeff and offset won't cause an overflow */
+	ret = thermal_multi_sensor_validate_coeff(coeff, count, offset);
+
+	kfree(coeff);
+
+	return ret;
+}
+
+static int thermal_of_mutli_sensor_coeff(struct device_node *sensor, int id,
+					 struct device_node *tz_np,
+					 u32 *coeff)
+{
+	int index;
+	int ret;
+
+	index = thermal_of_multi_sensor_get_id(sensor, tz_np, id);
+	if (index < 0)
+		return index;
+
+	ret = of_property_read_u32_index(tz_np, "coefficients", index, coeff);
+	if (ret)
+		*coeff = 1;
+
+	return 0;
+}
+
+static struct thermal_zone_device *
+thermal_of_register_multi_tz(struct device_node *sensor, int id, struct device_node *np,
+			     const char *type, struct thermal_trip *trips, int num_trips,
+			     void *devdata, struct thermal_zone_device_ops *ops,
+			     const struct thermal_zone_params *tzp, int passive_delay,
+			     int polling_delay)
+{
+	struct thermal_zone_device *multi_tz, *tz;
+	char name[THERMAL_NAME_LENGTH];
+	u32 coeff;
+	int ret;
+
+	multi_tz = thermal_multi_sensor_find_tz(type);
+	if (!multi_tz) {
+		struct thermal_zone_device_ops *multi_ops;
+
+		ret = thermal_of_multi_sensor_validate_coeff(sensor, id, np);
+		if (ret)
+			return ERR_PTR(ret);
+
+		multi_ops = thermal_multi_sensor_alloc_ops();
+		if (IS_ERR_OR_NULL(multi_ops))
+			return ERR_PTR(PTR_ERR(multi_ops));
+		multi_ops->bind = thermal_of_bind;
+		multi_ops->unbind = thermal_of_unbind;
+
+		multi_tz = thermal_multi_sensor_tz_alloc(type, trips, num_trips,
+							 multi_ops,
+							 passive_delay, polling_delay);
+		if (IS_ERR_OR_NULL(multi_tz)) {
+			kfree(multi_ops);
+			return multi_tz;
+		}
+	}
+
+	ret = thermal_of_multi_sensor_get_name(sensor, id, np, name);
+	if (ret)
+		goto out_release_multi_tz;
+
+	tz = thermal_tripless_zone_device_register(name, devdata, ops, tzp);
+	if (IS_ERR_OR_NULL(tz)) {
+		ret = PTR_ERR(tz);
+		goto out_release_multi_tz;
+	}
+
+	ret = thermal_of_mutli_sensor_coeff(sensor, id, np, &coeff);
+	if (ret)
+		goto out_release_tz;
+
+	ret = thermal_multi_sensor_register(multi_tz, tz, coeff);
+	if (ret)
+		goto out_release_tz;
+
+	return tz;
+
+out_release_tz:
+	thermal_zone_device_unregister(tz);
+out_release_multi_tz:
+	thermal_multi_sensor_tz_free(multi_tz);
+
+	return ERR_PTR(ret);
+}
+
+
 /**
  * thermal_of_zone_register - Register a thermal zone with device node
  * sensor
@@ -479,6 +693,7 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
 	const char *action;
 	int delay, pdelay;
 	int ntrips;
+	int count;
 	int ret;
 
 	np = of_thermal_zone_find(sensor, id);
@@ -488,10 +703,19 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
 		return ERR_CAST(np);
 	}
 
-	trips = thermal_of_trips_init(np, &ntrips);
-	if (IS_ERR(trips)) {
-		pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
-		return ERR_CAST(trips);
+	count = of_count_phandle_with_args(np, "thermal-sensors",
+						"#thermal-sensor-cells");
+	if (count <= 0)
+		return ERR_PTR(count);
+
+	/* Only allocate trips if the thermal zone doesn't exist yet */
+	if (!thermal_multi_sensor_find_tz(np->name)) {
+		trips = thermal_of_trips_init(np, &ntrips);
+		if (IS_ERR(trips)) {
+			pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
+			ret = PTR_ERR(trips);
+			goto out_kfree_trips;
+		}
 	}
 
 	ret = thermal_of_monitor_init(np, &delay, &pdelay);
@@ -502,17 +726,25 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
 
 	thermal_of_parameters_init(np, &tzp);
 
-	of_ops.bind = thermal_of_bind;
-	of_ops.unbind = thermal_of_unbind;
+	if (count == 1) {
+		of_ops.bind = thermal_of_bind;
+		of_ops.unbind = thermal_of_unbind;
+	}
 
 	ret = of_property_read_string(np, "critical-action", &action);
 	if (!ret)
 		if (!of_ops.critical && !strcasecmp(action, "reboot"))
 			of_ops.critical = thermal_zone_device_critical_reboot;
 
-	tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
-						     data, &of_ops, &tzp,
-						     pdelay, delay);
+	if (count == 1) {
+		tz = thermal_zone_device_register_with_trips(np->name, trips, ntrips,
+							     data, &of_ops, &tzp,
+							     pdelay, delay);
+	} else {
+		tz = thermal_of_register_multi_tz(sensor, id, np, np->name, trips,
+						  ntrips, data, &of_ops, &tzp,
+						  pdelay, delay);
+	}
 	if (IS_ERR(tz)) {
 		ret = PTR_ERR(tz);
 		pr_err("Failed to register thermal zone %pOFn: %d\n", np, ret);
-- 
2.44.1

[PATCH v4 4/4] ARM64: mt8195: Use thermal aggregation for big and little cpu

[Alexandre Bailon]

This uses the thermal aggregation for the mt8195 to get the maximal
temperature of big and little cpu clusters.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
---
 arch/arm64/boot/dts/mediatek/mt8195.dtsi | 210 +++--------------------
 1 file changed, 25 insertions(+), 185 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt8195.dtsi b/arch/arm64/boot/dts/mediatek/mt8195.dtsi
index 5d8b68f86ce4..90778c609ceb 100644
--- a/arch/arm64/boot/dts/mediatek/mt8195.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8195.dtsi
@@ -3600,50 +3600,30 @@ dp_tx: dp-tx@1c600000 {
 	};
 
 	thermal_zones: thermal-zones {
-		cpu0-thermal {
+		cpu-little {
 			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_LITTLE_CPU0>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&lvts_mcu MT8195_MCU_LITTLE_CPU0>,
+					  <&lvts_mcu MT8195_MCU_LITTLE_CPU1>,
+					  <&lvts_mcu MT8195_MCU_LITTLE_CPU2>,
+					  <&lvts_mcu MT8195_MCU_LITTLE_CPU3>;
+			sustainable-power = <1500>;
 
 			trips {
-				cpu0_alert: trip-alert {
-					temperature = <85000>;
+				cpu_little_threshold: trip-point {
+					temperature = <68000>;
 					hysteresis = <2000>;
 					type = "passive";
 				};
 
-				cpu0_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu0_alert>;
-					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu1-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_LITTLE_CPU1>;
-
-			trips {
-				cpu1_alert: trip-alert {
+				cpu_little_target: target {
 					temperature = <85000>;
 					hysteresis = <2000>;
 					type = "passive";
 				};
 
-				cpu1_crit: trip-crit {
-					temperature = <100000>;
+				cpu_little_soc_max_crit: soc-max-crit {
+					temperature = <115000>;
 					hysteresis = <2000>;
 					type = "critical";
 				};
@@ -3651,7 +3631,7 @@ cpu1_crit: trip-crit {
 
 			cooling-maps {
 				map0 {
-					trip = <&cpu1_alert>;
+					trip = <&cpu_little_target>;
 					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 								<&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 								<&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
@@ -3660,170 +3640,30 @@ map0 {
 			};
 		};
 
-		cpu2-thermal {
+		cpu-big {
 			polling-delay = <1000>;
 			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_LITTLE_CPU2>;
+			thermal-sensors = <&lvts_mcu MT8195_MCU_BIG_CPU0>,
+					  <&lvts_mcu MT8195_MCU_BIG_CPU1>,
+					  <&lvts_mcu MT8195_MCU_BIG_CPU2>,
+					  <&lvts_mcu MT8195_MCU_BIG_CPU3>;
+			sustainable-power = <1500>;
 
 			trips {
-				cpu2_alert: trip-alert {
-					temperature = <85000>;
+				cpu_big_threshold: trip-point {
+					temperature = <68000>;
 					hysteresis = <2000>;
 					type = "passive";
 				};
 
-				cpu2_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu2_alert>;
-					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu3-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_LITTLE_CPU3>;
-
-			trips {
-				cpu3_alert: trip-alert {
-					temperature = <85000>;
-					hysteresis = <2000>;
-					type = "passive";
-				};
-
-				cpu3_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu3_alert>;
-					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu4-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_BIG_CPU0>;
-
-			trips {
-				cpu4_alert: trip-alert {
+				cpu_big_target: target {
 					temperature = <85000>;
 					hysteresis = <2000>;
 					type = "passive";
 				};
 
-				cpu4_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu4_alert>;
-					cooling-device = <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu5-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_BIG_CPU1>;
-
-			trips {
-				cpu5_alert: trip-alert {
-					temperature = <85000>;
-					hysteresis = <2000>;
-					type = "passive";
-				};
-
-				cpu5_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu5_alert>;
-					cooling-device = <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu6-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_BIG_CPU2>;
-
-			trips {
-				cpu6_alert: trip-alert {
-					temperature = <85000>;
-					hysteresis = <2000>;
-					type = "passive";
-				};
-
-				cpu6_crit: trip-crit {
-					temperature = <100000>;
-					hysteresis = <2000>;
-					type = "critical";
-				};
-			};
-
-			cooling-maps {
-				map0 {
-					trip = <&cpu6_alert>;
-					cooling-device = <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-								<&cpu7 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
-				};
-			};
-		};
-
-		cpu7-thermal {
-			polling-delay = <1000>;
-			polling-delay-passive = <250>;
-			thermal-sensors = <&lvts_mcu MT8195_MCU_BIG_CPU3>;
-
-			trips {
-				cpu7_alert: trip-alert {
-					temperature = <85000>;
-					hysteresis = <2000>;
-					type = "passive";
-				};
-
-				cpu7_crit: trip-crit {
-					temperature = <100000>;
+				cpu_big_soc_max_crit: soc-max-crit {
+					temperature = <115000>;
 					hysteresis = <2000>;
 					type = "critical";
 				};
@@ -3831,7 +3671,7 @@ cpu7_crit: trip-crit {
 
 			cooling-maps {
 				map0 {
-					trip = <&cpu7_alert>;
+					trip = <&cpu_big_target>;
 					cooling-device = <&cpu4 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 								<&cpu5 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
 								<&cpu6 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
-- 
2.44.1

Re: [PATCH v4 0/4] thermal: Add support of multiple sensors

[Daniel Lezcano]

Hi Alexandre,

thanks for your series and my apologizes for taking a so long time to 
review.

I went through the series and at the first glance I'm not sure we want 
to add all the multi specific code in a separate file.

IMO, there is a preparatory work by changing the functions:

thermal_zone_device_register_with_trips() and 
thermal_zone_device_register_tripless()

where we group and move the functions parameters to the 
thermal_zone_device_param.

Then we can add a num_ops field which is will default to zero.

With that we should have put a foundation for multiple ops, so multiple 
sensors.

On 13/06/2024 15:24, Alexandre Bailon wrote:
> Following this comment [1], this updates thermal_of to support multiple
> sensors.
> 
> This series intends to add support of thermal aggregation.
> One use case for it is using the IPA in the case we have
> multiple sensors for one performance domain.
> 
> This has been tested on the mt8195 using s-tui.
> To test and validate, we heat up the CPU and the heat sink.
> At some point, we run benchmark tests with different configurations:
> - Mediatek kernel (IPA + their own thermal aggregation)
> - Mainline kernel
> - Mainline kernel with IPA and aggregation enabled
> With the IPA and the aggregation enabled, we get the best performances
> with the most stable CPU temperature.
> 
> The aggregation is configured and enabled using device tree.
> One thermal zone has to be created with a list of sensors.
> It will take care of registering a thermal zone for each sensors.
> The cooling device will only be registered with the aggregating thermal
> zone.
> 
> There are still something important missing: a way to check that all
> aggregated sensors are part of the same performance domain.
> So far, I don't see how this should be done. Some recommendations would be
> appreciated.
> 
> Changes in v2:
> - Rebased on 6.7
> - Separated generic multi sensor and dt specific code
> - Simplified the code
> - Drop min / max and only do weighted average (seems more adequate for IPA)
> 
> Changes in v3:
> - Rebased on 6.9
> - Reworked the way to register a multi sensor thermal zone
>    - Only one thermal zone to define in device tree
> - Max has been re-added
> - Enabled it on mt8195
> 
> Changes in v4:
> - Rebased on lastest master (fixed the build issue)
> - Dropped the average since I don't have any usecase for it
> 
> [1]: https://patchwork.kernel.org/comment/24723927/
> 
> Alexandre Bailon (4):
>    dt-bindings: thermal: Restore the thermal-sensors property
>    thermal: Add support of multi sensors to thermal_core
>    thermal: Add support of multi sensors to thermal_of
>    ARM64: mt8195: Use thermal aggregation for big and little cpu
> 
>   .../bindings/thermal/thermal-zones.yaml       |   5 +-
>   arch/arm64/boot/dts/mediatek/mt8195.dtsi      | 212 ++-----------
>   drivers/thermal/Makefile                      |   1 +
>   drivers/thermal/thermal_core.h                |  15 +
>   drivers/thermal/thermal_multi.c               | 288 ++++++++++++++++++
>   drivers/thermal/thermal_of.c                  | 250 ++++++++++++++-
>   include/uapi/linux/thermal.h                  |   5 +
>   7 files changed, 579 insertions(+), 197 deletions(-)
>   create mode 100644 drivers/thermal/thermal_multi.c
> 

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