[PATCH v5 0/5] Thermal: Support for hardware-tracked trip points

[PATCH v5 0/5] Thermal: Support for hardware-tracked trip points

[Caesar Wang]

Thank you all for providing inputs and comments on previous versions of
this patchset.
Especially thanks to the (Mikko,Sascha,Eduardo,Javi,Steve....).

The history patches come from Mikko and Sascha.
    http://thread.gmane.org/gmane.linux.power-management.general/59451

Now, I pick them up to continue upstream.
Nevermind!

This series history patches:
v4: https://lkml.org/lkml/2016/5/27/122
v3: https://lkml.org/lkml/2016/5/24/797
v2: https://lkml.org/lkml/2016/5/3/220
v1: https://lkml.org/lkml/2016/4/24/227

This series adds support for hardware trip points. It picks up earlier
work from Mikko Perttunen. Mikko implemented hardware trip points as part
of the device tree support. It was suggested back then to move the
functionality to the thermal core instead of putting more code into the
device tree support. This series does exactly that.

This series patches rebase the conflicts with the lastest next kernel.
Note that the hardware-tracked trip points are very well tested currently.

Verified and tested on https://github.com/Caesar-github/rockchip/tree/wip/fixes-thermal-0606
That's based on the next kernel (4.7-rc2).
localhost / # cat /proc/version
Linux version 4.7.0-rc2-next-20160606-02546-g534926d (wxt@nb)
---
There are five pathes in this series.
thermal: Add support for hardware-tracked trip point
thermal: of: implement .set_trips for device tree thermal zones
thermal: streamline get_trend callbacks
thermal: bang-bang governor: act on lower trip boundary
thermal: rockchip: add the set_trips function

Note: the hardware-tracked trip points that the similar patches were verified
on ChromoeOs platform.
e.g.:
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.14
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.18
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4
---

Anyway, I take the lastest thermal change to test from next kernel,

Tested on RK3399 SoCs on https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4
And
Tested on RK3288 SoCs with chromebook on next kernel.
localhost / # while true; do grep "" /sys/class/thermal/thermal_zone[0-1]/temp; sleep .5; done
/sys/class/thermal/thermal_zone1/temp:45454
/sys/class/thermal/thermal_zone2/temp:44090
/sys/class/thermal/thermal_zone1/temp:44545
/sys/class/thermal/thermal_zone2/temp:44545
/sys/class/thermal/thermal_zone1/temp:45454
/sys/class/thermal/thermal_zone2/temp:44545
/sys/class/thermal/thermal_zone1/temp:45000
...
Then add the loading,
localhost / # md5sum /dev/zero &
[3] 8354
..
The Set trips trigger the hardware-tracked points.

rockchip-thermal ff280000.tsadc: sensor 1 - temp: 68461, retval: 0
rockchip-thermal ff280000.tsadc: sensor 2 - temp: 64166, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 75000
rockchip-thermal ff280000.tsadc: sensor 2 - temp: 66153, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 70000
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 68076, retval: 0
rockchip-thermal ff280000.tsadc: sensor 2 - temp: 65384, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 75000
rockchip-thermal ff280000.tsadc: sensor 2 - temp: 65384, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 70000
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70833, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 75000
rockchip-thermal ff280000.tsadc: sensor 2 - temp: 66153, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 70000
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70416, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 75000
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 70000
rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor 1: low: 68000, high 75000
..
---
Anyway, the series patches are verified on rockchip platform.

Thanks someone are reviewing and testing for it.

-Caesar


Changes in v5:
- add the lock for thermal_zone_set_trips function.
- change based on next kernel.
- add the tested by Steve.

Changes in v4:
- Missing the lock added in v3.
- as the Javi comments, %s/implemnets/implements.

Changes in v3:
- as Javi comments on https://patchwork.kernel.org/patch/9001281/.
- add the lock for preventing the called from multi placce
- add the note for pre_low/high_trip.
- as the Javi comments on https://patchwork.kernel.org/patch/9001311/.
- add the select if they set the option for devicetree.
- Add the peter's ACK.

Changes in v2:
- update the sysfs-api.txt for set_trips.
- add the commit in patch[v2 2/5].
- Update the commit for patch[v2 4/5].

Caesar Wang (1):
  thermal: rockchip: add the set_trips function

Sascha Hauer (4):
  thermal: Add support for hardware-tracked trip points
  thermal: of: implement .set_trips for device tree thermal zones
  thermal: streamline get_trend callbacks
  thermal: bang-bang governor: act on lower trip boundary

 Documentation/thermal/sysfs-api.txt                |  7 +++
 drivers/thermal/gov_bang_bang.c                    |  2 +-
 drivers/thermal/of-thermal.c                       | 30 ++++++++----
 drivers/thermal/rockchip_thermal.c                 | 39 ++++++++++++++++
 drivers/thermal/thermal_core.c                     | 54 ++++++++++++++++++++++
 drivers/thermal/thermal_sysfs.c                    |  3 ++
 drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 25 ++++------
 include/linux/thermal.h                            | 16 ++++++-
 8 files changed, 147 insertions(+), 29 deletions(-)

-- 
1.9.1

[PATCH v5 1/5] thermal: Add support for hardware-tracked trip points

[Caesar Wang]

From: Sascha Hauer <s.hauer@pengutronix.de>

This adds support for hardware-tracked trip points to the device tree
thermal sensor framework.

The framework supports an arbitrary number of trip points. Whenever
the current temperature is updated, the trip points immediately
below and above the current temperature are found. A .set_trips
callback is then called with the temperatures. If there is no trip
point above or below the current temperature, the passed trip
temperature will be -INT_MAX or INT_MAX respectively. In this callback,
the driver should program the hardware such that it is notified
when either of these trip points are triggered. When a trip point
is triggered, the driver should call `thermal_zone_device_update'
for the respective thermal zone. This will cause the trip points
to be updated again.

If .set_trips is not implemented, the framework behaves as before.

This patch is based on an earlier version from Mikko Perttunen
<mikko.perttunen@kapsi.fi>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org

---

Changes in v5:
- add the lock for thermal_zone_set_trips function.
- change based on next kernel.

Changes in v4:
- Missing the lock added in v3.

Changes in v3:
- as Javi comments on https://patchwork.kernel.org/patch/9001281/.
- add the lock for preventing the called from multi placce
- add the note for pre_low/high_trip.

Changes in v2:
- update the sysfs-api.txt for set_trips.

 Documentation/thermal/sysfs-api.txt |  7 +++++
 drivers/thermal/thermal_core.c      | 54 +++++++++++++++++++++++++++++++++++++
 drivers/thermal/thermal_sysfs.c     |  3 +++
 include/linux/thermal.h             | 10 +++++++
 4 files changed, 74 insertions(+)

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index efc3f3d..75d8838 100644
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -49,6 +49,9 @@ temperature) and throttle appropriate devices.
 	.bind: bind the thermal zone device with a thermal cooling device.
 	.unbind: unbind the thermal zone device with a thermal cooling device.
 	.get_temp: get the current temperature of the thermal zone.
+	.set_trips: set the trip points window. Whenever the current temperature
+		    is updated, the trip points immediately below and above the
+		    current temperature are found.
 	.get_mode: get the current mode (enabled/disabled) of the thermal zone.
 	    - "enabled" means the kernel thermal management is enabled.
 	    - "disabled" will prevent kernel thermal driver action upon trip points
@@ -95,6 +98,10 @@ temperature) and throttle appropriate devices.
 			get_temp:	a pointer to a function that reads the
 					sensor temperature. This is mandatory
 					callback provided by sensor driver.
+			set_trips:      a pointer to a function that sets a
+					temperature window. When this window is
+					left the driver must inform the thermal
+					core via thermal_zone_device_update.
 			get_trend: 	a pointer to a function that reads the
 					sensor temperature trend.
 			set_emul_temp:	a pointer to a function that sets
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 792aab7..e69aee2 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -368,6 +368,56 @@ static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 	monitor_thermal_zone(tz);
 }
 
+void thermal_zone_set_trips(struct thermal_zone_device *tz)
+{
+	int low = -INT_MAX;
+	int high = INT_MAX;
+	int trip_temp, hysteresis;
+	int i, ret;
+
+	mutex_lock(&tz->lock);
+
+	if (!tz->ops->set_trips)
+		goto exit;
+
+	for (i = 0; i < tz->trips; i++) {
+		int trip_low;
+
+		tz->ops->get_trip_temp(tz, i, &trip_temp);
+		tz->ops->get_trip_hyst(tz, i, &hysteresis);
+
+		trip_low = trip_temp - hysteresis;
+
+		if (trip_low < tz->temperature && trip_low > low)
+			low = trip_low;
+
+		if (trip_temp > tz->temperature && trip_temp < high)
+			high = trip_temp;
+	}
+
+	/* No need to change trip points */
+	if (tz->prev_low_trip == low && tz->prev_high_trip == high)
+		goto exit;
+
+	tz->prev_low_trip = low;
+	tz->prev_high_trip = high;
+
+	dev_dbg(&tz->device, "new temperature boundaries: %d < x < %d\n",
+			low, high);
+
+	/*
+	 * Set a temperature window. When this window is left the driver
+	 * must inform the thermal core via thermal_zone_device_update.
+	 */
+	ret = tz->ops->set_trips(tz, low, high);
+	if (ret)
+		dev_err(&tz->device, "Failed to set trips: %d\n", ret);
+
+exit:
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_set_trips);
+
 static void update_temperature(struct thermal_zone_device *tz)
 {
 	int temp, ret;
@@ -417,6 +467,8 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 
 	update_temperature(tz);
 
+	thermal_zone_set_trips(tz);
+
 	for (count = 0; count < tz->trips; count++)
 		handle_thermal_trip(tz, count);
 }
@@ -1175,6 +1227,8 @@ thermal_zone_device_register(const char *type, int trips, int mask,
 	tz->trips = trips;
 	tz->passive_delay = passive_delay;
 	tz->polling_delay = polling_delay;
+	tz->prev_low_trip = INT_MAX;
+	tz->prev_high_trip = -INT_MAX;
 
 	/* sys I/F */
 	/* Add nodes that are always present via .groups */
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 743df50..33bbe30 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -219,6 +219,9 @@ trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
 	ret = tz->ops->set_trip_hyst(tz, trip, temperature);
 	mutex_unlock(&tz->lock);
 
+	if (!ret)
+		thermal_zone_set_trips(tz);
+
 	return ret ? ret : count;
 }
 
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index ea667b6..780e69d 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -99,6 +99,7 @@ struct thermal_zone_device_ops {
 	int (*unbind) (struct thermal_zone_device *,
 		       struct thermal_cooling_device *);
 	int (*get_temp) (struct thermal_zone_device *, int *);
+	int (*set_trips) (struct thermal_zone_device *, int, int);
 	int (*get_mode) (struct thermal_zone_device *,
 			 enum thermal_device_mode *);
 	int (*set_mode) (struct thermal_zone_device *,
@@ -169,6 +170,10 @@ struct thermal_attr {
  * @last_temperature:	previous temperature read
  * @emul_temperature:	emulated temperature when using CONFIG_THERMAL_EMULATION
  * @passive:		1 if you've crossed a passive trip point, 0 otherwise.
+ * @prev_low_trip:	the low current temperature if you've crossed a passive
+			trip point.
+ * @prev_high_trip:	the above current temperature if you've crossed a
+			passive trip point.
  * @forced_passive:	If > 0, temperature at which to switch on all ACPI
  *			processor cooling devices.  Currently only used by the
  *			step-wise governor.
@@ -201,6 +206,8 @@ struct thermal_zone_device {
 	int last_temperature;
 	int emul_temperature;
 	int passive;
+	int prev_low_trip;
+	int prev_high_trip;
 	unsigned int forced_passive;
 	atomic_t need_update;
 	struct thermal_zone_device_ops *ops;
@@ -428,6 +435,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *, int,
 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, int,
 				       struct thermal_cooling_device *);
 void thermal_zone_device_update(struct thermal_zone_device *);
+void thermal_zone_set_trips(struct thermal_zone_device *);
 
 struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
 		const struct thermal_cooling_device_ops *);
@@ -477,6 +485,8 @@ static inline int thermal_zone_unbind_cooling_device(
 { return -ENODEV; }
 static inline void thermal_zone_device_update(struct thermal_zone_device *tz)
 { }
+static inline void thermal_zone_set_trips(struct thermal_zone_device *tz)
+{ }
 static inline struct thermal_cooling_device *
 thermal_cooling_device_register(char *type, void *devdata,
 	const struct thermal_cooling_device_ops *ops)
-- 
1.9.1

[PATCH v5 2/5] thermal: of: implement .set_trips for device tree thermal zones

[Caesar Wang]

From: Sascha Hauer <s.hauer@pengutronix.de>

This patch implements .set_trips for device tree thermal zones.
As the hardware-tracked trip points is supported by thermal core patch[0].

patch[0]
"thermal: Add support for hardware-tracked trip points".

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Reviewed-by: Javi Merino <javi.merino@arm.com>

---

Changes in v5: None
Changes in v4:
- as the Javi comments, %s/implemnets/implements.

Changes in v3:
- as the Javi comments on https://patchwork.kernel.org/patch/9001311/.
- add the select if they set the option for devicetree.

Changes in v2:
- add the commit in patch[v2 2/5].

 drivers/thermal/of-thermal.c | 19 +++++++++++++++++++
 include/linux/thermal.h      |  4 ++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index b8e509c..2d2a06f 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -101,6 +101,17 @@ static int of_thermal_get_temp(struct thermal_zone_device *tz,
 	return data->ops->get_temp(data->sensor_data, temp);
 }
 
+static int of_thermal_set_trips(struct thermal_zone_device *tz,
+				int low, int high)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (!data->ops || !data->ops->set_trips)
+		return -EINVAL;
+
+	return data->ops->set_trips(data->sensor_data, low, high);
+}
+
 /**
  * of_thermal_get_ntrips - function to export number of available trip
  *			   points.
@@ -427,6 +438,14 @@ thermal_zone_of_add_sensor(struct device_node *zone,
 
 	tzd->ops->get_temp = of_thermal_get_temp;
 	tzd->ops->get_trend = of_thermal_get_trend;
+
+	/*
+	 * The thermal zone core will calculate the window if they have set the
+	 * optional set_trips pointer.
+	 */
+	if (ops->set_trips)
+		tzd->ops->set_trips = of_thermal_set_trips;
+
 	tzd->ops->set_emul_temp = of_thermal_set_emul_temp;
 	mutex_unlock(&tzd->lock);
 
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 780e69d..2440b8d 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -342,6 +342,9 @@ struct thermal_genl_event {
  *
  * Optional:
  * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ * @set_trips: a pointer to a function that sets a temperature window. When
+ *	       this window is left the driver must inform the thermal core via
+ *	       thermal_zone_device_update.
  * @set_emul_temp: a pointer to a function that sets sensor emulated
  *		   temperature.
  * @set_trip_temp: a pointer to a function that sets the trip temperature on
@@ -350,6 +353,7 @@ struct thermal_genl_event {
 struct thermal_zone_of_device_ops {
 	int (*get_temp)(void *, int *);
 	int (*get_trend)(void *, long *);
+	int (*set_trips)(void *, int, int);
 	int (*set_emul_temp)(void *, int);
 	int (*set_trip_temp)(void *, int, int);
 };
-- 
1.9.1

[PATCH v5 3/5] thermal: streamline get_trend callbacks

[Caesar Wang]

From: Sascha Hauer <s.hauer@pengutronix.de>

The .get_trend callback in struct thermal_zone_device_ops has
the prototype:
        int (*get_trend) (struct thermal_zone_device *, int,
                          enum thermal_trend *);
whereas the .get_trend callback in struct thermal_zone_of_device_ops
has:
        int (*get_trend)(void *, long *);

Streamline both prototypes and add the trip argument to the OF callback
aswell and use enum thermal_trend * instead of an integer pointer.

While the OF prototype may be the better one, this should be decided at
framework level and not on OF level.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/thermal/of-thermal.c                       | 11 +---------
 drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 25 +++++++---------------
 include/linux/thermal.h                            |  2 +-
 3 files changed, 10 insertions(+), 28 deletions(-)

diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
index 2d2a06f..ba72c35 100644
--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c
@@ -202,24 +202,15 @@ 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->ops->get_trend)
 		return -EINVAL;
 
-	r = data->ops->get_trend(data->sensor_data, &dev_trend);
+	r = data->ops->get_trend(data->sensor_data, trip, trend);
 	if (r)
 		return r;
 
-	/* TODO: These intervals might have some thresholds, but in core code */
-	if (dev_trend > 0)
-		*trend = THERMAL_TREND_RAISING;
-	else if (dev_trend < 0)
-		*trend = THERMAL_TREND_DROPPING;
-	else
-		*trend = THERMAL_TREND_STABLE;
-
 	return 0;
 }
 
diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
index 15c0a9a..4a6757c 100644
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -239,7 +239,7 @@ static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	return 0;
 }
 
-static int __ti_thermal_get_trend(void *p, long *trend)
+static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
 {
 	struct ti_thermal_data *data = p;
 	struct ti_bandgap *bgp;
@@ -252,22 +252,6 @@ static int __ti_thermal_get_trend(void *p, long *trend)
 	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)
@@ -278,6 +262,13 @@ static int ti_thermal_get_trend(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)
+{
+	return __ti_thermal_get_trend(thermal->devdata, trip, trend);
+}
+
 /* Get critical temperature callback functions for thermal zone */
 static int ti_thermal_get_crit_temp(struct thermal_zone_device *thermal,
 				    int *temp)
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index 2440b8d..d3ce3a5 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -352,7 +352,7 @@ struct thermal_genl_event {
  */
 struct thermal_zone_of_device_ops {
 	int (*get_temp)(void *, int *);
-	int (*get_trend)(void *, long *);
+	int (*get_trend)(void *, int, enum thermal_trend *);
 	int (*set_trips)(void *, int, int);
 	int (*set_emul_temp)(void *, int);
 	int (*set_trip_temp)(void *, int, int);
-- 
1.9.1

[PATCH v5 4/5] thermal: bang-bang governor: act on lower trip boundary

[Caesar Wang]

From: Sascha Hauer <s.hauer@pengutronix.de>

With interrupt driven thermal zones we pass the lower and upper
temperature on which shall be acted, so in the governor we have to act on
the exact lower temperature to be consistent. Otherwise an interrupt maybe
generated on the exact lower temperature, but the bang bang governor does
not react since The polling driven zones have to be one step cooler before
the governor reacts.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
Acked-by: Peter Feuerer <peter@piie.net>

---

Changes in v5: None
Changes in v4: None
Changes in v3:
- Add the peter's ACK.

Changes in v2:
- Update the commit for patch[v2 4/5].

 drivers/thermal/gov_bang_bang.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/gov_bang_bang.c b/drivers/thermal/gov_bang_bang.c
index fc52016..5073871 100644
--- a/drivers/thermal/gov_bang_bang.c
+++ b/drivers/thermal/gov_bang_bang.c
@@ -65,7 +65,7 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
 		if (instance->target == 0 && tz->temperature >= trip_temp)
 			instance->target = 1;
 		else if (instance->target == 1 &&
-				tz->temperature < trip_temp - trip_hyst)
+				tz->temperature <= trip_temp - trip_hyst)
 			instance->target = 0;
 
 		dev_dbg(&instance->cdev->device, "target=%d\n",
-- 
1.9.1

[PATCH v5 5/5] thermal: rockchip: add the set_trips function

[Caesar Wang]

Whenever the current temperature is updated, the trip points immediately
below and above the current temperature are found. A sensor driver
callback `set_trips' is then called with the temperatures.
Lastly, The sensor will trigger the hardware high temperature interrupts
to increase the sampleing rate and throttle frequency to limit the
temperature rising When performing passive cooling.

Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
Tested-by: Stephen Barber <smbarber@chromium.org>

---

Changes in v5:
- add the tested by Steve.

Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/thermal/rockchip_thermal.c | 39 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
index 5d491f1..8175cdb 100644
--- a/drivers/thermal/rockchip_thermal.c
+++ b/drivers/thermal/rockchip_thermal.c
@@ -96,6 +96,7 @@ struct chip_tsadc_table {
  * @initialize: SoC special initialize tsadc controller method
  * @irq_ack: clear the interrupt
  * @get_temp: get the temperature
+ * @set_alarm_temp: set the high temperature interrupt
  * @set_tshut_temp: set the hardware-controlled shutdown temperature
  * @set_tshut_mode: set the hardware-controlled shutdown mode
  * @table: the chip-specific conversion table
@@ -119,6 +120,8 @@ struct rockchip_tsadc_chip {
 	/* Per-sensor methods */
 	int (*get_temp)(struct chip_tsadc_table table,
 			int chn, void __iomem *reg, int *temp);
+	void (*set_alarm_temp)(struct chip_tsadc_table table,
+			       int chn, void __iomem *reg, int temp);
 	void (*set_tshut_temp)(struct chip_tsadc_table table,
 			       int chn, void __iomem *reg, int temp);
 	void (*set_tshut_mode)(int chn, void __iomem *reg, enum tshut_mode m);
@@ -183,6 +186,7 @@ struct rockchip_thermal_data {
 #define TSADCV2_INT_EN				0x08
 #define TSADCV2_INT_PD				0x0c
 #define TSADCV2_DATA(chn)			(0x20 + (chn) * 0x04)
+#define TSADCV2_COMP_INT(chn)		        (0x30 + (chn) * 0x04)
 #define TSADCV2_COMP_SHUT(chn)		        (0x40 + (chn) * 0x04)
 #define TSADCV2_HIGHT_INT_DEBOUNCE		0x60
 #define TSADCV2_HIGHT_TSHUT_DEBOUNCE		0x64
@@ -628,6 +632,20 @@ static int rk_tsadcv2_get_temp(struct chip_tsadc_table table,
 	return rk_tsadcv2_code_to_temp(table, val, temp);
 }
 
+static void rk_tsadcv2_alarm_temp(struct chip_tsadc_table table,
+				  int chn, void __iomem *regs, int temp)
+{
+	u32 alarm_value, int_en;
+
+	alarm_value = rk_tsadcv2_temp_to_code(table, temp);
+	writel_relaxed(alarm_value & table.data_mask,
+		       regs + TSADCV2_COMP_INT(chn));
+
+	int_en = readl_relaxed(regs + TSADCV2_INT_EN);
+	int_en |= TSADCV2_INT_SRC_EN(chn);
+	writel_relaxed(int_en, regs + TSADCV2_INT_EN);
+}
+
 static void rk_tsadcv2_tshut_temp(struct chip_tsadc_table table,
 				  int chn, void __iomem *regs, int temp)
 {
@@ -670,6 +688,7 @@ static const struct rockchip_tsadc_chip rk3228_tsadc_data = {
 	.irq_ack = rk_tsadcv3_irq_ack,
 	.control = rk_tsadcv3_control,
 	.get_temp = rk_tsadcv2_get_temp,
+	.set_alarm_temp = rk_tsadcv2_alarm_temp,
 	.set_tshut_temp = rk_tsadcv2_tshut_temp,
 	.set_tshut_mode = rk_tsadcv2_tshut_mode,
 
@@ -694,6 +713,7 @@ static const struct rockchip_tsadc_chip rk3288_tsadc_data = {
 	.irq_ack = rk_tsadcv2_irq_ack,
 	.control = rk_tsadcv2_control,
 	.get_temp = rk_tsadcv2_get_temp,
+	.set_alarm_temp = rk_tsadcv2_alarm_temp,
 	.set_tshut_temp = rk_tsadcv2_tshut_temp,
 	.set_tshut_mode = rk_tsadcv2_tshut_mode,
 
@@ -718,6 +738,7 @@ static const struct rockchip_tsadc_chip rk3366_tsadc_data = {
 	.irq_ack = rk_tsadcv3_irq_ack,
 	.control = rk_tsadcv3_control,
 	.get_temp = rk_tsadcv2_get_temp,
+	.set_alarm_temp = rk_tsadcv2_alarm_temp,
 	.set_tshut_temp = rk_tsadcv2_tshut_temp,
 	.set_tshut_mode = rk_tsadcv2_tshut_mode,
 
@@ -742,6 +763,7 @@ static const struct rockchip_tsadc_chip rk3368_tsadc_data = {
 	.irq_ack = rk_tsadcv2_irq_ack,
 	.control = rk_tsadcv2_control,
 	.get_temp = rk_tsadcv2_get_temp,
+	.set_alarm_temp = rk_tsadcv2_alarm_temp,
 	.set_tshut_temp = rk_tsadcv2_tshut_temp,
 	.set_tshut_mode = rk_tsadcv2_tshut_mode,
 
@@ -766,6 +788,7 @@ static const struct rockchip_tsadc_chip rk3399_tsadc_data = {
 	.irq_ack = rk_tsadcv3_irq_ack,
 	.control = rk_tsadcv3_control,
 	.get_temp = rk_tsadcv2_get_temp,
+	.set_alarm_temp = rk_tsadcv2_alarm_temp,
 	.set_tshut_temp = rk_tsadcv2_tshut_temp,
 	.set_tshut_mode = rk_tsadcv2_tshut_mode,
 
@@ -826,6 +849,21 @@ static irqreturn_t rockchip_thermal_alarm_irq_thread(int irq, void *dev)
 	return IRQ_HANDLED;
 }
 
+static int rockchip_thermal_set_trips(void *_sensor, int low, int high)
+{
+	struct rockchip_thermal_sensor *sensor = _sensor;
+	struct rockchip_thermal_data *thermal = sensor->thermal;
+	const struct rockchip_tsadc_chip *tsadc = thermal->chip;
+
+	dev_dbg(&thermal->pdev->dev, "%s: sensor %d: low: %d, high %d\n",
+		__func__, sensor->id, low, high);
+
+	tsadc->set_alarm_temp(tsadc->table,
+			      sensor->id, thermal->regs, high);
+
+	return 0;
+}
+
 static int rockchip_thermal_get_temp(void *_sensor, int *out_temp)
 {
 	struct rockchip_thermal_sensor *sensor = _sensor;
@@ -843,6 +881,7 @@ static int rockchip_thermal_get_temp(void *_sensor, int *out_temp)
 
 static const struct thermal_zone_of_device_ops rockchip_of_thermal_ops = {
 	.get_temp = rockchip_thermal_get_temp,
+	.set_trips = rockchip_thermal_set_trips,
 };
 
 static int rockchip_configure_from_dt(struct device *dev,
-- 
1.9.1

Re: [PATCH v5 1/5] thermal: Add support for hardware-tracked trip points

[Javi Merino]

On Mon, Jun 06, 2016 at 07:44:45PM +0800, Caesar Wang wrote:
> From: Sascha Hauer <s.hauer@pengutronix.de>
> 
> This adds support for hardware-tracked trip points to the device tree
> thermal sensor framework.
> 
> The framework supports an arbitrary number of trip points. Whenever
> the current temperature is updated, the trip points immediately
> below and above the current temperature are found. A .set_trips
> callback is then called with the temperatures. If there is no trip
> point above or below the current temperature, the passed trip
> temperature will be -INT_MAX or INT_MAX respectively. In this callback,
> the driver should program the hardware such that it is notified
> when either of these trip points are triggered. When a trip point
> is triggered, the driver should call `thermal_zone_device_update'
> for the respective thermal zone. This will cause the trip points
> to be updated again.
> 
> If .set_trips is not implemented, the framework behaves as before.
> 
> This patch is based on an earlier version from Mikko Perttunen
> <mikko.perttunen@kapsi.fi>
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Cc: linux-pm@vger.kernel.org
> 
> ---
> 
> Changes in v5:
> - add the lock for thermal_zone_set_trips function.

Looks good to me!

Reviewed-by: Javi Merino <javi.merino@arm.com>

> - change based on next kernel.
> 
> Changes in v4:
> - Missing the lock added in v3.
> 
> Changes in v3:
> - as Javi comments on https://patchwork.kernel.org/patch/9001281/.
> - add the lock for preventing the called from multi placce
> - add the note for pre_low/high_trip.
> 
> Changes in v2:
> - update the sysfs-api.txt for set_trips.
> 
>  Documentation/thermal/sysfs-api.txt |  7 +++++
>  drivers/thermal/thermal_core.c      | 54 +++++++++++++++++++++++++++++++++++++
>  drivers/thermal/thermal_sysfs.c     |  3 +++
>  include/linux/thermal.h             | 10 +++++++
>  4 files changed, 74 insertions(+)
> 

Re: [PATCH v5 3/5] thermal: streamline get_trend callbacks

[Keerthy]

On Monday 06 June 2016 05:14 PM, Caesar Wang wrote:
> From: Sascha Hauer <s.hauer@pengutronix.de>
>
> The .get_trend callback in struct thermal_zone_device_ops has
> the prototype:
>          int (*get_trend) (struct thermal_zone_device *, int,
>                            enum thermal_trend *);
> whereas the .get_trend callback in struct thermal_zone_of_device_ops
> has:
>          int (*get_trend)(void *, long *);
>
> Streamline both prototypes and add the trip argument to the OF callback
> aswell and use enum thermal_trend * instead of an integer pointer.
>
> While the OF prototype may be the better one, this should be decided at
> framework level and not on OF level.

Tested this patch on omap5-uevm using emulation feature and saw that
cooling state was getting updated correctly w.r.t trip point tempereatures.

A minor comment below apart from that.

Reviewed-by: Keerthy <j-keerthy@ti.com>

>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Cc: linux-pm@vger.kernel.org
> ---
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
>   drivers/thermal/of-thermal.c                       | 11 +---------
>   drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 25 +++++++---------------
>   include/linux/thermal.h                            |  2 +-
>   3 files changed, 10 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
> index 2d2a06f..ba72c35 100644
> --- a/drivers/thermal/of-thermal.c
> +++ b/drivers/thermal/of-thermal.c
> @@ -202,24 +202,15 @@ 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;

	int r = 0;

>
>   	if (!data->ops->get_trend)
>   		return -EINVAL;
>
> -	r = data->ops->get_trend(data->sensor_data, &dev_trend);
> +	r = data->ops->get_trend(data->sensor_data, trip, trend);
>   	if (r)
>   		return r;

no need of this if check just
	
	return r;

>
> -	/* TODO: These intervals might have some thresholds, but in core code */
> -	if (dev_trend > 0)
> -		*trend = THERMAL_TREND_RAISING;
> -	else if (dev_trend < 0)
> -		*trend = THERMAL_TREND_DROPPING;
> -	else
> -		*trend = THERMAL_TREND_STABLE;
> -
>   	return 0;
>   }
>
> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> index 15c0a9a..4a6757c 100644
> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> @@ -239,7 +239,7 @@ static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
>   	return 0;
>   }
>
> -static int __ti_thermal_get_trend(void *p, long *trend)
> +static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
>   {
>   	struct ti_thermal_data *data = p;
>   	struct ti_bandgap *bgp;
> @@ -252,22 +252,6 @@ static int __ti_thermal_get_trend(void *p, long *trend)
>   	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)
> @@ -278,6 +262,13 @@ static int ti_thermal_get_trend(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)
> +{
> +	return __ti_thermal_get_trend(thermal->devdata, trip, trend);
> +}
> +
>   /* Get critical temperature callback functions for thermal zone */
>   static int ti_thermal_get_crit_temp(struct thermal_zone_device *thermal,
>   				    int *temp)
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index 2440b8d..d3ce3a5 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -352,7 +352,7 @@ struct thermal_genl_event {
>    */
>   struct thermal_zone_of_device_ops {
>   	int (*get_temp)(void *, int *);
> -	int (*get_trend)(void *, long *);
> +	int (*get_trend)(void *, int, enum thermal_trend *);
>   	int (*set_trips)(void *, int, int);
>   	int (*set_emul_temp)(void *, int);
>   	int (*set_trip_temp)(void *, int, int);
>

Re: [PATCH v5 3/5] thermal: streamline get_trend callbacks

[Caesar Wang]

On 2016年06月07日 14:14, Keerthy wrote:
>
>
> On Monday 06 June 2016 05:14 PM, Caesar Wang wrote:
>> From: Sascha Hauer <s.hauer@pengutronix.de>
>>
>> The .get_trend callback in struct thermal_zone_device_ops has
>> the prototype:
>> int (*get_trend) (struct thermal_zone_device *, int,
>> enum thermal_trend *);
>> whereas the .get_trend callback in struct thermal_zone_of_device_ops
>> has:
>> int (*get_trend)(void *, long *);
>>
>> Streamline both prototypes and add the trip argument to the OF callback
>> aswell and use enum thermal_trend * instead of an integer pointer.
>>
>> While the OF prototype may be the better one, this should be decided at
>> framework level and not on OF level.
>
> Tested this patch on omap5-uevm using emulation feature and saw that
> cooling state was getting updated correctly w.r.t trip point 
> tempereatures.
>
> A minor comment below apart from that.
>
> Reviewed-by: Keerthy <j-keerthy@ti.com>
>
>>
>> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
>> Cc: Zhang Rui <rui.zhang@intel.com>
>> Cc: Eduardo Valentin <edubezval@gmail.com>
>> Cc: linux-pm@vger.kernel.org
>> ---
>>
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3: None
>> Changes in v2: None
>>
>> drivers/thermal/of-thermal.c | 11 +---------
>> drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 25 
>> +++++++---------------
>> include/linux/thermal.h | 2 +-
>> 3 files changed, 10 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
>> index 2d2a06f..ba72c35 100644
>> --- a/drivers/thermal/of-thermal.c
>> +++ b/drivers/thermal/of-thermal.c
>> @@ -202,24 +202,15 @@ 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;
>
> int r = 0;
>
>>
>> if (!data->ops->get_trend)
>> return -EINVAL;
>>
>> - r = data->ops->get_trend(data->sensor_data, &dev_trend);
>> + r = data->ops->get_trend(data->sensor_data, trip, trend);
>> if (r)
>> return r;
>
> no need of this if check just
>
> return r;

Maybe, we can return it with "data->ops->get_trend(data->sensor_data, 
trip, trend)"

return data->ops->get_trend(data->sensor_data, trip, trend);
>
>>
>> - /* TODO: These intervals might have some thresholds, but in core 
>> code */
>> - if (dev_trend > 0)
>> - *trend = THERMAL_TREND_RAISING;
>> - else if (dev_trend < 0)
>> - *trend = THERMAL_TREND_DROPPING;
>> - else
>> - *trend = THERMAL_TREND_STABLE;
>> -
>> return 0;
>> }
>>
>> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c 
>> b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> index 15c0a9a..4a6757c 100644
>> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
>> @@ -239,7 +239,7 @@ static int ti_thermal_get_trip_temp(struct 
>> thermal_zone_device *thermal,
>> return 0;
>> }
>>
>> -static int __ti_thermal_get_trend(void *p, long *trend)
>> +static int __ti_thermal_get_trend(void *p, int trip, enum 
>> thermal_trend *trend)
>> {
>> struct ti_thermal_data *data = p;
>> struct ti_bandgap *bgp;
>> @@ -252,22 +252,6 @@ static int __ti_thermal_get_trend(void *p, long 
>> *trend)
>> 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)
>> @@ -278,6 +262,13 @@ static int ti_thermal_get_trend(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)
>> +{
>> + return __ti_thermal_get_trend(thermal->devdata, trip, trend);
>> +}
>> +
>> /* Get critical temperature callback functions for thermal zone */
>> static int ti_thermal_get_crit_temp(struct thermal_zone_device *thermal,
>> int *temp)
>> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
>> index 2440b8d..d3ce3a5 100644
>> --- a/include/linux/thermal.h
>> +++ b/include/linux/thermal.h
>> @@ -352,7 +352,7 @@ struct thermal_genl_event {
>> */
>> struct thermal_zone_of_device_ops {
>> int (*get_temp)(void *, int *);
>> - int (*get_trend)(void *, long *);
>> + int (*get_trend)(void *, int, enum thermal_trend *);
>> int (*set_trips)(void *, int, int);
>> int (*set_emul_temp)(void *, int);
>> int (*set_trip_temp)(void *, int, int);
>>
>
>
>

-- 
caesar wang | software engineer | wxt@rock-chip.com

Re: [PATCH v5 1/5] thermal: Add support for hardware-tracked trip points

[Zhang Rui]

On 一, 2016-06-06 at 19:44 +0800, Caesar Wang wrote:
> From: Sascha Hauer <s.hauer@pengutronix.de>
> 
> This adds support for hardware-tracked trip points to the device tree
> thermal sensor framework.
> 
> The framework supports an arbitrary number of trip points. Whenever
> the current temperature is updated, the trip points immediately
> below and above the current temperature are found. A .set_trips
> callback is then called with the temperatures. If there is no trip
> point above or below the current temperature, the passed trip
> temperature will be -INT_MAX or INT_MAX respectively. In this
> callback,
> the driver should program the hardware such that it is notified
> when either of these trip points are triggered. When a trip point
> is triggered, the driver should call `thermal_zone_device_update'
> for the respective thermal zone. This will cause the trip points
> to be updated again.
> 
> If .set_trips is not implemented, the framework behaves as before.
> 
> This patch is based on an earlier version from Mikko Perttunen
> <mikko.perttunen@kapsi.fi>
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Cc: linux-pm@vger.kernel.org
> 
> ---
> 
> Changes in v5:
> - add the lock for thermal_zone_set_trips function.
> - change based on next kernel.
> 
> Changes in v4:
> - Missing the lock added in v3.
> 
> Changes in v3:
> - as Javi comments on https://patchwork.kernel.org/patch/9001281/.
> - add the lock for preventing the called from multi placce
> - add the note for pre_low/high_trip.
> 
> Changes in v2:
> - update the sysfs-api.txt for set_trips.
> 
>  Documentation/thermal/sysfs-api.txt |  7 +++++
>  drivers/thermal/thermal_core.c      | 54
> +++++++++++++++++++++++++++++++++++++
>  drivers/thermal/thermal_sysfs.c     |  3 +++
>  include/linux/thermal.h             | 10 +++++++
>  4 files changed, 74 insertions(+)
> 
> diff --git a/Documentation/thermal/sysfs-api.txt
> b/Documentation/thermal/sysfs-api.txt
> index efc3f3d..75d8838 100644
> --- a/Documentation/thermal/sysfs-api.txt
> +++ b/Documentation/thermal/sysfs-api.txt
> @@ -49,6 +49,9 @@ temperature) and throttle appropriate devices.
>  	.bind: bind the thermal zone device with a thermal cooling
> device.
>  	.unbind: unbind the thermal zone device with a thermal
> cooling device.
>  	.get_temp: get the current temperature of the thermal zone.
> +	.set_trips: set the trip points window. Whenever the current
> temperature
> +		    is updated, the trip points immediately below
> and above the
> +		    current temperature are found.
>  	.get_mode: get the current mode (enabled/disabled) of the
> thermal zone.
>  	    - "enabled" means the kernel thermal management is
> enabled.
>  	    - "disabled" will prevent kernel thermal driver action
> upon trip points
> @@ -95,6 +98,10 @@ temperature) and throttle appropriate devices.
>  			get_temp:	a pointer to a function
> that reads the
>  					sensor temperature. This is
> mandatory
>  					callback provided by sensor
> driver.
> +			set_trips:      a pointer to a function that
> sets a
> +					temperature window. When
> this window is
> +					left the driver must inform
> the thermal
> +					core via
> thermal_zone_device_update.
>  			get_trend: 	a pointer to a function
> that reads the
>  					sensor temperature trend.
>  			set_emul_temp:	a pointer to a
> function that sets
> diff --git a/drivers/thermal/thermal_core.c
> b/drivers/thermal/thermal_core.c
> index 792aab7..e69aee2 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -368,6 +368,56 @@ static void handle_thermal_trip(struct
> thermal_zone_device *tz, int trip)
>  	monitor_thermal_zone(tz);
>  }
>  
> +void thermal_zone_set_trips(struct thermal_zone_device *tz)
> +{
> +	int low = -INT_MAX;
> +	int high = INT_MAX;
> +	int trip_temp, hysteresis;
> +	int i, ret;
> +
> +	mutex_lock(&tz->lock);
> +
> +	if (!tz->ops->set_trips)
> +		goto exit;
> +
	if (!tz->ops->get_trip_hyst)
		goto exit;

otherwise, the patch looks good to me.

thanks,
rui
> +	for (i = 0; i < tz->trips; i++) {
> +		int trip_low;
> +
> +		tz->ops->get_trip_temp(tz, i, &trip_temp);
> +		tz->ops->get_trip_hyst(tz, i, &hysteresis);
> +
> +		trip_low = trip_temp - hysteresis;
> +
> +		if (trip_low < tz->temperature && trip_low > low)
> +			low = trip_low;
> +
> +		if (trip_temp > tz->temperature && trip_temp < high)
> +			high = trip_temp;
> +	}
> +
> +	/* No need to change trip points */
> +	if (tz->prev_low_trip == low && tz->prev_high_trip == high)
> +		goto exit;
> +
> +	tz->prev_low_trip = low;
> +	tz->prev_high_trip = high;
> +
> +	dev_dbg(&tz->device, "new temperature boundaries: %d < x <
> %d\n",
> +			low, high);
> +
> +	/*
> +	 * Set a temperature window. When this window is left the
> driver
> +	 * must inform the thermal core via
> thermal_zone_device_update.
> +	 */
> +	ret = tz->ops->set_trips(tz, low, high);
> +	if (ret)
> +		dev_err(&tz->device, "Failed to set trips: %d\n",
> ret);
> +
> +exit:
> +	mutex_unlock(&tz->lock);
> +}
> +EXPORT_SYMBOL_GPL(thermal_zone_set_trips);
> +
>  static void update_temperature(struct thermal_zone_device *tz)
>  {
>  	int temp, ret;
> @@ -417,6 +467,8 @@ void thermal_zone_device_update(struct
> thermal_zone_device *tz)
>  
>  	update_temperature(tz);
>  
> +	thermal_zone_set_trips(tz);
> +
>  	for (count = 0; count < tz->trips; count++)
>  		handle_thermal_trip(tz, count);
>  }
> @@ -1175,6 +1227,8 @@ thermal_zone_device_register(const char *type,
> int trips, int mask,
>  	tz->trips = trips;
>  	tz->passive_delay = passive_delay;
>  	tz->polling_delay = polling_delay;
> +	tz->prev_low_trip = INT_MAX;
> +	tz->prev_high_trip = -INT_MAX;
>  
>  	/* sys I/F */
>  	/* Add nodes that are always present via .groups */
> diff --git a/drivers/thermal/thermal_sysfs.c
> b/drivers/thermal/thermal_sysfs.c
> index 743df50..33bbe30 100644
> --- a/drivers/thermal/thermal_sysfs.c
> +++ b/drivers/thermal/thermal_sysfs.c
> @@ -219,6 +219,9 @@ trip_point_hyst_store(struct device *dev, struct
> device_attribute *attr,
>  	ret = tz->ops->set_trip_hyst(tz, trip, temperature);
>  	mutex_unlock(&tz->lock);
>  
> +	if (!ret)
> +		thermal_zone_set_trips(tz);
> +
>  	return ret ? ret : count;
>  }
>  
> diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> index ea667b6..780e69d 100644
> --- a/include/linux/thermal.h
> +++ b/include/linux/thermal.h
> @@ -99,6 +99,7 @@ struct thermal_zone_device_ops {
>  	int (*unbind) (struct thermal_zone_device *,
>  		       struct thermal_cooling_device *);
>  	int (*get_temp) (struct thermal_zone_device *, int *);
> +	int (*set_trips) (struct thermal_zone_device *, int, int);
>  	int (*get_mode) (struct thermal_zone_device *,
>  			 enum thermal_device_mode *);
>  	int (*set_mode) (struct thermal_zone_device *,
> @@ -169,6 +170,10 @@ struct thermal_attr {
>   * @last_temperature:	previous temperature read
>   * @emul_temperature:	emulated temperature when using
> CONFIG_THERMAL_EMULATION
>   * @passive:		1 if you've crossed a passive trip
> point, 0 otherwise.
> + * @prev_low_trip:	the low current temperature if you've
> crossed a passive
> +			trip point.
> + * @prev_high_trip:	the above current temperature if you've
> crossed a
> +			passive trip point.
>   * @forced_passive:	If > 0, temperature at which to switch on
> all ACPI
>   *			processor cooling devices.  Currently only
> used by the
>   *			step-wise governor.
> @@ -201,6 +206,8 @@ struct thermal_zone_device {
>  	int last_temperature;
>  	int emul_temperature;
>  	int passive;
> +	int prev_low_trip;
> +	int prev_high_trip;
>  	unsigned int forced_passive;
>  	atomic_t need_update;
>  	struct thermal_zone_device_ops *ops;
> @@ -428,6 +435,7 @@ int thermal_zone_bind_cooling_device(struct
> thermal_zone_device *, int,
>  int thermal_zone_unbind_cooling_device(struct thermal_zone_device *,
> int,
>  				       struct thermal_cooling_device
> *);
>  void thermal_zone_device_update(struct thermal_zone_device *);
> +void thermal_zone_set_trips(struct thermal_zone_device *);
>  
>  struct thermal_cooling_device *thermal_cooling_device_register(char
> *, void *,
>  		const struct thermal_cooling_device_ops *);
> @@ -477,6 +485,8 @@ static inline int
> thermal_zone_unbind_cooling_device(
>  { return -ENODEV; }
>  static inline void thermal_zone_device_update(struct
> thermal_zone_device *tz)
>  { }
> +static inline void thermal_zone_set_trips(struct thermal_zone_device
> *tz)
> +{ }
>  static inline struct thermal_cooling_device *
>  thermal_cooling_device_register(char *type, void *devdata,
>  	const struct thermal_cooling_device_ops *ops)

Re: [PATCH v5 0/5] Thermal: Support for hardware-tracked trip points

[Zhang Rui]

On 二, 2016-06-21 at 09:42 +0800, Caesar Wang wrote:
> Do you have other ideas for the following patches? :-) 
> Even if only took two weeks feel after a long time.
> 
> 9157919 New          [v5,1/5] thermal: Add support for hardware-
> tracked trip points
> 9157917 New          [v5,2/5] thermal: of: implement .set_trips for
> device tree thermal zones
> 9161129 New          [v5.1,3/5] thermal: streamline get_trend
> callbacks
> 9157929 New          [v5,4/5] thermal: bang-bang governor: act on
> lower trip boundary
> 9157925 New          [v5,5/5] thermal: rockchip: add the set_trips
> function
> ---
> 
I have no objections to this patch set, except one change in patch 1/5.
But as this also touches of_thermal and rockchip thermal driver. I'd
leave this patch set for Eduardo to review and take.
BTW, Eduardo is traveling recently, so you may still need to wait some
time.

Thanks,
rui
> 
> Caesar
> 
> On 2016年06月06日 19:44, Caesar Wang wrote:
> > Thank you all for providing inputs and comments on previous
> > versions of
> > this patchset.
> > Especially thanks to the (Mikko,Sascha,Eduardo,Javi,Steve....).
> > 
> > The history patches come from Mikko and Sascha.
> >     http://thread.gmane.org/gmane.linux.power-management.general/59
> > 451
> > 
> > Now, I pick them up to continue upstream.
> > Nevermind!
> > 
> > This series history patches:
> > v4: https://lkml.org/lkml/2016/5/27/122
> > v3: https://lkml.org/lkml/2016/5/24/797
> > v2: https://lkml.org/lkml/2016/5/3/220
> > v1: https://lkml.org/lkml/2016/4/24/227
> > 
> > This series adds support for hardware trip points. It picks up
> > earlier
> > work from Mikko Perttunen. Mikko implemented hardware trip points
> > as part
> > of the device tree support. It was suggested back then to move the
> > functionality to the thermal core instead of putting more code into
> > the
> > device tree support. This series does exactly that.
> > 
> > This series patches rebase the conflicts with the lastest next
> > kernel.
> > Note that the hardware-tracked trip points are very well tested
> > currently.
> > 
> > Verified and tested on https://github.com/Caesar-github/rockchip/tr
> > ee/wip/fixes-thermal-0606
> > That's based on the next kernel (4.7-rc2).
> > localhost / # cat /proc/version
> > Linux version 4.7.0-rc2-next-20160606-02546-g534926d (wxt@nb)
> > ---
> > There are five pathes in this series.
> > thermal: Add support for hardware-tracked trip point
> > thermal: of: implement .set_trips for device tree thermal zones
> > thermal: streamline get_trend callbacks
> > thermal: bang-bang governor: act on lower trip boundary
> > thermal: rockchip: add the set_trips function
> > 
> > Note: the hardware-tracked trip points that the similar patches
> > were verified
> > on ChromoeOs platform.
> > e.g.:
> > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/c
> > hromeos-3.14
> > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/c
> > hromeos-3.18
> > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/c
> > hromeos-4.4
> > ---
> > 
> > Anyway, I take the lastest thermal change to test from next kernel,
> > 
> > Tested on RK3399 SoCs on https://chromium.googlesource.com/chromium
> > os/third_party/kernel/+/chromeos-4.4
> > And
> > Tested on RK3288 SoCs with chromebook on next kernel.
> > localhost / # while true; do grep ""
> > /sys/class/thermal/thermal_zone[0-1]/temp; sleep .5; done
> > /sys/class/thermal/thermal_zone1/temp:45454
> > /sys/class/thermal/thermal_zone2/temp:44090
> > /sys/class/thermal/thermal_zone1/temp:44545
> > /sys/class/thermal/thermal_zone2/temp:44545
> > /sys/class/thermal/thermal_zone1/temp:45454
> > /sys/class/thermal/thermal_zone2/temp:44545
> > /sys/class/thermal/thermal_zone1/temp:45000
> > ...
> > Then add the loading,
> > localhost / # md5sum /dev/zero &
> > [3] 8354
> > ..
> > The Set trips trigger the hardware-tracked points.
> > 
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 68461, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 2 - temp: 64166, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 75000
> > rockchip-thermal ff280000.tsadc: sensor 2 - temp: 66153, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 70000
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 68076, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 2 - temp: 65384, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 75000
> > rockchip-thermal ff280000.tsadc: sensor 2 - temp: 65384, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 70000
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70833, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 75000
> > rockchip-thermal ff280000.tsadc: sensor 2 - temp: 66153, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69230, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 70000
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70416, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 75000
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 69615, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 70000
> > rockchip-thermal ff280000.tsadc: sensor 1 - temp: 70000, retval: 0
> > rockchip-thermal ff280000.tsadc: rockchip_thermal_set_trips: sensor
> > 1: low: 68000, high 75000
> > ..
> > ---
> > Anyway, the series patches are verified on rockchip platform.
> > 
> > Thanks someone are reviewing and testing for it.
> > 
> > -Caesar
> > 
> > 
> > Changes in v5:
> > - add the lock for thermal_zone_set_trips function.
> > - change based on next kernel.
> > - add the tested by Steve.
> > 
> > Changes in v4:
> > - Missing the lock added in v3.
> > - as the Javi comments, %s/implemnets/implements.
> > 
> > Changes in v3:
> > - as Javi comments on https://patchwork.kernel.org/patch/9001281/.
> > - add the lock for preventing the called from multi placce
> > - add the note for pre_low/high_trip.
> > - as the Javi comments on https://patchwork.kernel.org/patch/900131
> > 1/.
> > - add the select if they set the option for devicetree.
> > - Add the peter's ACK.
> > 
> > Changes in v2:
> > - update the sysfs-api.txt for set_trips.
> > - add the commit in patch[v2 2/5].
> > - Update the commit for patch[v2 4/5].
> > 
> > Caesar Wang (1):
> >   thermal: rockchip: add the set_trips function
> > 
> > Sascha Hauer (4):
> >   thermal: Add support for hardware-tracked trip points
> >   thermal: of: implement .set_trips for device tree thermal zones
> >   thermal: streamline get_trend callbacks
> >   thermal: bang-bang governor: act on lower trip boundary
> > 
> >  Documentation/thermal/sysfs-api.txt                |  7 +++
> >  drivers/thermal/gov_bang_bang.c                    |  2 +-
> >  drivers/thermal/of-thermal.c                       | 30 ++++++++
> > ----
> >  drivers/thermal/rockchip_thermal.c                 | 39
> > ++++++++++++++++
> >  drivers/thermal/thermal_core.c                     | 54
> > ++++++++++++++++++++++
> >  drivers/thermal/thermal_sysfs.c                    |  3 ++
> >  drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 25 ++++------
> >  include/linux/thermal.h                            | 16 ++++++-
> >  8 files changed, 147 insertions(+), 29 deletions(-)
> > 
>  

Re: [PATCH v5 0/5] Thermal: Support for hardware-tracked trip points

[Caesar Wang]

On 2016年06月22日 11:25, Zhang Rui wrote:
> On 二, 2016-06-21 at 09:42 +0800, Caesar Wang wrote:
>> Do you have other ideas for the following patches? :-)
>> Even if only took two weeks feel after a long time.
>>
>> 9157919 New          [v5,1/5] thermal: Add support for hardware-
>> tracked trip points
>> 9157917 New          [v5,2/5] thermal: of: implement .set_trips for
>> device tree thermal zones
>> 9161129 New          [v5.1,3/5] thermal: streamline get_trend
>> callbacks
>> 9157929 New          [v5,4/5] thermal: bang-bang governor: act on
>> lower trip boundary
>> 9157925 New          [v5,5/5] thermal: rockchip: add the set_trips
>> function
>> ---
>>
> I have no objections to this patch set, except one change in patch 1/5.
> But as this also touches of_thermal and rockchip thermal driver. I'd
> leave this patch set for Eduardo to review and take.
> BTW, Eduardo is traveling recently, so you may still need to wait some
> time.

Okay, thanks for your reminder. and sorry for the noise.:-)

-
Caesar

>
> Thanks,
> rui
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip

Re: [PATCH v5 1/5] thermal: Add support for hardware-tracked trip points

[Eduardo Valentin]

On Wed, Jun 22, 2016 at 11:15:19AM +0800, Zhang Rui wrote:
> On 一, 2016-06-06 at 19:44 +0800, Caesar Wang wrote:
> > From: Sascha Hauer <s.hauer@pengutronix.de>
> > 
> > This adds support for hardware-tracked trip points to the device tree
> > thermal sensor framework.
> > 
> > The framework supports an arbitrary number of trip points. Whenever
> > the current temperature is updated, the trip points immediately
> > below and above the current temperature are found. A .set_trips
> > callback is then called with the temperatures. If there is no trip
> > point above or below the current temperature, the passed trip
> > temperature will be -INT_MAX or INT_MAX respectively. In this
> > callback,
> > the driver should program the hardware such that it is notified
> > when either of these trip points are triggered. When a trip point
> > is triggered, the driver should call `thermal_zone_device_update'
> > for the respective thermal zone. This will cause the trip points
> > to be updated again.
> > 
> > If .set_trips is not implemented, the framework behaves as before.
> > 
> > This patch is based on an earlier version from Mikko Perttunen
> > <mikko.perttunen@kapsi.fi>
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > Signed-off-by: Caesar Wang <wxt@rock-chips.com>
> > Cc: Zhang Rui <rui.zhang@intel.com>
> > Cc: Eduardo Valentin <edubezval@gmail.com>
> > Cc: linux-pm@vger.kernel.org
> > 
> > ---
> > 
> > Changes in v5:
> > - add the lock for thermal_zone_set_trips function.
> > - change based on next kernel.
> > 
> > Changes in v4:
> > - Missing the lock added in v3.
> > 
> > Changes in v3:
> > - as Javi comments on https://patchwork.kernel.org/patch/9001281/.
> > - add the lock for preventing the called from multi placce
> > - add the note for pre_low/high_trip.
> > 
> > Changes in v2:
> > - update the sysfs-api.txt for set_trips.
> > 
> >  Documentation/thermal/sysfs-api.txt |  7 +++++
> >  drivers/thermal/thermal_core.c      | 54
> > +++++++++++++++++++++++++++++++++++++
> >  drivers/thermal/thermal_sysfs.c     |  3 +++
> >  include/linux/thermal.h             | 10 +++++++
> >  4 files changed, 74 insertions(+)
> > 
> > diff --git a/Documentation/thermal/sysfs-api.txt
> > b/Documentation/thermal/sysfs-api.txt
> > index efc3f3d..75d8838 100644
> > --- a/Documentation/thermal/sysfs-api.txt
> > +++ b/Documentation/thermal/sysfs-api.txt
> > @@ -49,6 +49,9 @@ temperature) and throttle appropriate devices.
> >  	.bind: bind the thermal zone device with a thermal cooling
> > device.
> >  	.unbind: unbind the thermal zone device with a thermal
> > cooling device.
> >  	.get_temp: get the current temperature of the thermal zone.
> > +	.set_trips: set the trip points window. Whenever the current
> > temperature
> > +		    is updated, the trip points immediately below
> > and above the
> > +		    current temperature are found.
> >  	.get_mode: get the current mode (enabled/disabled) of the
> > thermal zone.
> >  	    - "enabled" means the kernel thermal management is
> > enabled.
> >  	    - "disabled" will prevent kernel thermal driver action
> > upon trip points
> > @@ -95,6 +98,10 @@ temperature) and throttle appropriate devices.
> >  			get_temp:	a pointer to a function
> > that reads the
> >  					sensor temperature. This is
> > mandatory
> >  					callback provided by sensor
> > driver.
> > +			set_trips:      a pointer to a function that
> > sets a
> > +					temperature window. When
> > this window is
> > +					left the driver must inform
> > the thermal
> > +					core via
> > thermal_zone_device_update.
> >  			get_trend: 	a pointer to a function
> > that reads the
> >  					sensor temperature trend.
> >  			set_emul_temp:	a pointer to a
> > function that sets
> > diff --git a/drivers/thermal/thermal_core.c
> > b/drivers/thermal/thermal_core.c
> > index 792aab7..e69aee2 100644
> > --- a/drivers/thermal/thermal_core.c
> > +++ b/drivers/thermal/thermal_core.c
> > @@ -368,6 +368,56 @@ static void handle_thermal_trip(struct
> > thermal_zone_device *tz, int trip)
> >  	monitor_thermal_zone(tz);
> >  }
> >  
> > +void thermal_zone_set_trips(struct thermal_zone_device *tz)
> > +{
> > +	int low = -INT_MAX;
> > +	int high = INT_MAX;
> > +	int trip_temp, hysteresis;
> > +	int i, ret;
> > +
> > +	mutex_lock(&tz->lock);
> > +
> > +	if (!tz->ops->set_trips)
> > +		goto exit;
> > +
> 	if (!tz->ops->get_trip_hyst)
> 		goto exit;
> 
> otherwise, the patch looks good to me.

Agreed here, you need to check if get_trip_hyst is present before
calling it. Not all drivers have it.

Besides, I would prefer you to lock after the checks:

	if (!tz->ops->set_trips)
		return;

	if (!tz->ops->get_trip_hyst)
		return;

	mutex_lock(&tz->lock);

> 
> thanks,
> rui
> > +	for (i = 0; i < tz->trips; i++) {
> > +		int trip_low;
> > +
> > +		tz->ops->get_trip_temp(tz, i, &trip_temp);
> > +		tz->ops->get_trip_hyst(tz, i, &hysteresis);
> > +
> > +		trip_low = trip_temp - hysteresis;
> > +
> > +		if (trip_low < tz->temperature && trip_low > low)
> > +			low = trip_low;
> > +
> > +		if (trip_temp > tz->temperature && trip_temp < high)
> > +			high = trip_temp;
> > +	}
> > +
> > +	/* No need to change trip points */
> > +	if (tz->prev_low_trip == low && tz->prev_high_trip == high)
> > +		goto exit;
> > +
> > +	tz->prev_low_trip = low;
> > +	tz->prev_high_trip = high;
> > +
> > +	dev_dbg(&tz->device, "new temperature boundaries: %d < x <
> > %d\n",
> > +			low, high);
> > +
> > +	/*
> > +	 * Set a temperature window. When this window is left the
> > driver
> > +	 * must inform the thermal core via
> > thermal_zone_device_update.
> > +	 */
> > +	ret = tz->ops->set_trips(tz, low, high);
> > +	if (ret)
> > +		dev_err(&tz->device, "Failed to set trips: %d\n",
> > ret);
> > +
> > +exit:
> > +	mutex_unlock(&tz->lock);
> > +}
> > +EXPORT_SYMBOL_GPL(thermal_zone_set_trips);
> > +
> >  static void update_temperature(struct thermal_zone_device *tz)
> >  {
> >  	int temp, ret;
> > @@ -417,6 +467,8 @@ void thermal_zone_device_update(struct
> > thermal_zone_device *tz)
> >  
> >  	update_temperature(tz);
> >  
> > +	thermal_zone_set_trips(tz);
> > +
> >  	for (count = 0; count < tz->trips; count++)
> >  		handle_thermal_trip(tz, count);
> >  }
> > @@ -1175,6 +1227,8 @@ thermal_zone_device_register(const char *type,
> > int trips, int mask,
> >  	tz->trips = trips;
> >  	tz->passive_delay = passive_delay;
> >  	tz->polling_delay = polling_delay;
> > +	tz->prev_low_trip = INT_MAX;
> > +	tz->prev_high_trip = -INT_MAX;
> >  
> >  	/* sys I/F */
> >  	/* Add nodes that are always present via .groups */
> > diff --git a/drivers/thermal/thermal_sysfs.c
> > b/drivers/thermal/thermal_sysfs.c
> > index 743df50..33bbe30 100644
> > --- a/drivers/thermal/thermal_sysfs.c
> > +++ b/drivers/thermal/thermal_sysfs.c
> > @@ -219,6 +219,9 @@ trip_point_hyst_store(struct device *dev, struct
> > device_attribute *attr,
> >  	ret = tz->ops->set_trip_hyst(tz, trip, temperature);
> >  	mutex_unlock(&tz->lock);
> >  
> > +	if (!ret)
> > +		thermal_zone_set_trips(tz);
> > +
> >  	return ret ? ret : count;
> >  }
> >  
> > diff --git a/include/linux/thermal.h b/include/linux/thermal.h
> > index ea667b6..780e69d 100644
> > --- a/include/linux/thermal.h
> > +++ b/include/linux/thermal.h
> > @@ -99,6 +99,7 @@ struct thermal_zone_device_ops {
> >  	int (*unbind) (struct thermal_zone_device *,
> >  		       struct thermal_cooling_device *);
> >  	int (*get_temp) (struct thermal_zone_device *, int *);
> > +	int (*set_trips) (struct thermal_zone_device *, int, int);
> >  	int (*get_mode) (struct thermal_zone_device *,
> >  			 enum thermal_device_mode *);
> >  	int (*set_mode) (struct thermal_zone_device *,
> > @@ -169,6 +170,10 @@ struct thermal_attr {
> >   * @last_temperature:	previous temperature read
> >   * @emul_temperature:	emulated temperature when using
> > CONFIG_THERMAL_EMULATION
> >   * @passive:		1 if you've crossed a passive trip
> > point, 0 otherwise.
> > + * @prev_low_trip:	the low current temperature if you've
> > crossed a passive
> > +			trip point.
> > + * @prev_high_trip:	the above current temperature if you've
> > crossed a
> > +			passive trip point.
> >   * @forced_passive:	If > 0, temperature at which to switch on
> > all ACPI
> >   *			processor cooling devices.  Currently only
> > used by the
> >   *			step-wise governor.
> > @@ -201,6 +206,8 @@ struct thermal_zone_device {
> >  	int last_temperature;
> >  	int emul_temperature;
> >  	int passive;
> > +	int prev_low_trip;
> > +	int prev_high_trip;
> >  	unsigned int forced_passive;
> >  	atomic_t need_update;
> >  	struct thermal_zone_device_ops *ops;
> > @@ -428,6 +435,7 @@ int thermal_zone_bind_cooling_device(struct
> > thermal_zone_device *, int,
> >  int thermal_zone_unbind_cooling_device(struct thermal_zone_device *,
> > int,
> >  				       struct thermal_cooling_device
> > *);
> >  void thermal_zone_device_update(struct thermal_zone_device *);
> > +void thermal_zone_set_trips(struct thermal_zone_device *);
> >  
> >  struct thermal_cooling_device *thermal_cooling_device_register(char
> > *, void *,
> >  		const struct thermal_cooling_device_ops *);
> > @@ -477,6 +485,8 @@ static inline int
> > thermal_zone_unbind_cooling_device(
> >  { return -ENODEV; }
> >  static inline void thermal_zone_device_update(struct
> > thermal_zone_device *tz)
> >  { }
> > +static inline void thermal_zone_set_trips(struct thermal_zone_device
> > *tz)
> > +{ }
> >  static inline struct thermal_cooling_device *
> >  thermal_cooling_device_register(char *type, void *devdata,
> >  	const struct thermal_cooling_device_ops *ops)