Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux

Pull thermal management fixes from Zhang Rui:

 - Power allocator governor changes to allow binding on thermal zones
   with missing power estimates information.  From Javi Merino.

 - Add compile test flags on thermal drivers that allow it without
   producing compilation errors.  From Eduardo Valentin.

 - Fixes around memory allocation on cpu_cooling.  From Javi Merino.

 - Fix on db8500 cpufreq code to allow autoload.  From Luis de
   Bethencourt.

 - Maintainer entries for cpu cooling device

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: power_allocator: exit early if there are no cooling devices
  thermal: power_allocator: don't require tzp to be present for the thermal zone
  thermal: power_allocator: relax the requirement of two passive trip points
  thermal: power_allocator: relax the requirement of a sustainable_power in tzp
  thermal: Add a function to get the minimum power
  thermal: cpu_cooling: free power table on error or when unregistering
  thermal: cpu_cooling: don't call kcalloc() under rcu_read_lock
  thermal: db8500_cpufreq_cooling: Fix module autoload for OF platform driver
  thermal: cpu_cooling: Add MAINTAINERS entry
  thermal: ti-soc: Kconfig fix to avoid menu showing wrongly
  thermal: ti-soc: allow compile test
  thermal: qcom_spmi: allow compile test
  thermal: exynos: allow compile test
  thermal: armada: allow compile test
  thermal: dove: allow compile test
  thermal: kirkwood: allow compile test
  thermal: rockchip: allow compile test
  thermal: spear: allow compile test
  thermal: hisi: allow compile test
  thermal: Fix thermal_zone_of_sensor_register to match documentation

Documentation/thermal/power_allocator.txt

@@ -4,7 +4,7 @@ Power allocator governor tunables
 Trip points
 -----------
 
-The governor requires the following two passive trip points:
+The governor works optimally with the following two passive trip points:
 
 1.  "switch on" trip point: temperature above which the governor
     control loop starts operating.  This is the first passive trip

MAINTAINERS

@@ -10338,6 +10338,16 @@ F:	include/uapi/linux/thermal.h
 F:	include/linux/cpu_cooling.h
 F:	Documentation/devicetree/bindings/thermal/
 
+THERMAL/CPU_COOLING
+M:	Amit Daniel Kachhap <amit.kachhap@gmail.com>
+M:	Viresh Kumar <viresh.kumar@linaro.org>
+M:	Javi Merino <javi.merino@arm.com>
+L:	linux-pm@vger.kernel.org
+S:	Supported
+F:	Documentation/thermal/cpu-cooling-api.txt
+F:	drivers/thermal/cpu_cooling.c
+F:	include/linux/cpu_cooling.h
+
 THINGM BLINK(1) USB RGB LED DRIVER
 M:	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 S:	Maintained

drivers/thermal/Kconfig

@@ -163,7 +163,7 @@ config THERMAL_EMULATION
 
 config HISI_THERMAL
 	tristate "Hisilicon thermal driver"
-	depends on ARCH_HISI && CPU_THERMAL && OF
+	depends on (ARCH_HISI && CPU_THERMAL && OF) || COMPILE_TEST
 	help
 	  Enable this to plug hisilicon's thermal sensor driver into the Linux
 	  thermal framework. cpufreq is used as the cooling device to throttle
@@ -182,7 +182,7 @@ config IMX_THERMAL
 
 config SPEAR_THERMAL
 	bool "SPEAr thermal sensor driver"
-	depends on PLAT_SPEAR
+	depends on PLAT_SPEAR || COMPILE_TEST
 	depends on OF
 	help
 	  Enable this to plug the SPEAr thermal sensor driver into the Linux
@@ -190,7 +190,7 @@ config SPEAR_THERMAL
 
 config ROCKCHIP_THERMAL
 	tristate "Rockchip thermal driver"
-	depends on ARCH_ROCKCHIP
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
 	depends on RESET_CONTROLLER
 	help
 	  Rockchip thermal driver provides support for Temperature sensor
@@ -208,7 +208,7 @@ config RCAR_THERMAL
 
 config KIRKWOOD_THERMAL
 	tristate "Temperature sensor on Marvell Kirkwood SoCs"
-	depends on MACH_KIRKWOOD
+	depends on MACH_KIRKWOOD || COMPILE_TEST
 	depends on OF
 	help
 	  Support for the Kirkwood thermal sensor driver into the Linux thermal
@@ -216,7 +216,7 @@ config KIRKWOOD_THERMAL
 
 config DOVE_THERMAL
 	tristate "Temperature sensor on Marvell Dove SoCs"
-	depends on ARCH_DOVE || MACH_DOVE
+	depends on ARCH_DOVE || MACH_DOVE || COMPILE_TEST
 	depends on OF
 	help
 	  Support for the Dove thermal sensor driver in the Linux thermal
@@ -234,7 +234,7 @@ config DB8500_THERMAL
 
 config ARMADA_THERMAL
 	tristate "Armada 370/XP thermal management"
-	depends on ARCH_MVEBU
+	depends on ARCH_MVEBU || COMPILE_TEST
 	depends on OF
 	help
 	  Enable this option if you want to have support for thermal management
@@ -349,11 +349,12 @@ config INTEL_PCH_THERMAL
 	  programmable trip points and other information.
 
 menu "Texas Instruments thermal drivers"
+depends on ARCH_HAS_BANDGAP || COMPILE_TEST
 source "drivers/thermal/ti-soc-thermal/Kconfig"
 endmenu
 
 menu "Samsung thermal drivers"
-depends on ARCH_EXYNOS
+depends on ARCH_EXYNOS || COMPILE_TEST
 source "drivers/thermal/samsung/Kconfig"
 endmenu
 
@@ -364,7 +365,7 @@ endmenu
 
 config QCOM_SPMI_TEMP_ALARM
 	tristate "Qualcomm SPMI PMIC Temperature Alarm"
-	depends on OF && SPMI && IIO
+	depends on OF && (SPMI || COMPILE_TEST) && IIO
 	select REGMAP_SPMI
 	help
 	  This enables a thermal sysfs driver for Qualcomm plug-and-play (QPNP)

drivers/thermal/cpu_cooling.c

@@ -262,7 +262,9 @@ static int cpufreq_thermal_notifier(struct notifier_block *nb,
  * efficiently.  Power is stored in mW, frequency in KHz.  The
  * resulting table is in ascending order.
  *
- * Return: 0 on success, -E* on error.
+ * Return: 0 on success, -EINVAL if there are no OPPs for any CPUs,
+ * -ENOMEM if we run out of memory or -EAGAIN if an OPP was
+ * added/enabled while the function was executing.
  */
 static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 				 u32 capacitance)
@@ -273,8 +275,6 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 	int num_opps = 0, cpu, i, ret = 0;
 	unsigned long freq;
 
-	rcu_read_lock();
-
 	for_each_cpu(cpu, &cpufreq_device->allowed_cpus) {
 		dev = get_cpu_device(cpu);
 		if (!dev) {
@@ -284,24 +284,20 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		}
 
 		num_opps = dev_pm_opp_get_opp_count(dev);
-		if (num_opps > 0) {
+		if (num_opps > 0)
 			break;
-		} else if (num_opps < 0) {
-			ret = num_opps;
-			goto unlock;
-		}
+		else if (num_opps < 0)
+			return num_opps;
 	}
 
-	if (num_opps == 0) {
-		ret = -EINVAL;
-		goto unlock;
-	}
+	if (num_opps == 0)
+		return -EINVAL;
 
 	power_table = kcalloc(num_opps, sizeof(*power_table), GFP_KERNEL);
-	if (!power_table) {
-		ret = -ENOMEM;
-		goto unlock;
-	}
+	if (!power_table)
+		return -ENOMEM;
+
+	rcu_read_lock();
 
 	for (freq = 0, i = 0;
 	     opp = dev_pm_opp_find_freq_ceil(dev, &freq), !IS_ERR(opp);
@@ -309,6 +305,12 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		u32 freq_mhz, voltage_mv;
 		u64 power;
 
+		if (i >= num_opps) {
+			rcu_read_unlock();
+			ret = -EAGAIN;
+			goto free_power_table;
+		}
+
 		freq_mhz = freq / 1000000;
 		voltage_mv = dev_pm_opp_get_voltage(opp) / 1000;
 
@@ -326,17 +328,22 @@ static int build_dyn_power_table(struct cpufreq_cooling_device *cpufreq_device,
 		power_table[i].power = power;
 	}
 
-	if (i == 0) {
+	rcu_read_unlock();
+
+	if (i != num_opps) {
 		ret = PTR_ERR(opp);
-		goto unlock;
+		goto free_power_table;
 	}
 
 	cpufreq_device->cpu_dev = dev;
 	cpufreq_device->dyn_power_table = power_table;
 	cpufreq_device->dyn_power_table_entries = i;
 
-unlock:
-	rcu_read_unlock();
+	return 0;
+
+free_power_table:
+	kfree(power_table);
+
 	return ret;
 }
 
@@ -847,7 +854,7 @@ __cpufreq_cooling_register(struct device_node *np,
 	ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
 	if (ret) {
 		cool_dev = ERR_PTR(ret);
-		goto free_table;
+		goto free_power_table;
 	}
 
 	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
@@ -889,6 +896,8 @@ __cpufreq_cooling_register(struct device_node *np,
 
 remove_idr:
 	release_idr(&cpufreq_idr, cpufreq_dev->id);
+free_power_table:
+	kfree(cpufreq_dev->dyn_power_table);
 free_table:
 	kfree(cpufreq_dev->freq_table);
 free_time_in_idle_timestamp:
@@ -1039,6 +1048,7 @@ void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 
 	thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
 	release_idr(&cpufreq_idr, cpufreq_dev->id);
+	kfree(cpufreq_dev->dyn_power_table);
 	kfree(cpufreq_dev->time_in_idle_timestamp);
 	kfree(cpufreq_dev->time_in_idle);
 	kfree(cpufreq_dev->freq_table);

drivers/thermal/db8500_cpufreq_cooling.c

@@ -72,6 +72,7 @@ static const struct of_device_id db8500_cpufreq_cooling_match[] = {
 	{ .compatible = "stericsson,db8500-cpufreq-cooling" },
 	{},
 };
+MODULE_DEVICE_TABLE(of, db8500_cpufreq_cooling_match);
 #endif
 
 static struct platform_driver db8500_cpufreq_cooling_driver = {

drivers/thermal/power_allocator.c

@@ -24,6 +24,8 @@
 
 #include "thermal_core.h"
 
+#define INVALID_TRIP -1
+
 #define FRAC_BITS 10
 #define int_to_frac(x) ((x) << FRAC_BITS)
 #define frac_to_int(x) ((x) >> FRAC_BITS)
@@ -56,22 +58,109 @@ static inline s64 div_frac(s64 x, s64 y)
 
 /**
  * struct power_allocator_params - parameters for the power allocator governor
+ * @allocated_tzp:	whether we have allocated tzp for this thermal zone and
+ *			it needs to be freed on unbind
  * @err_integral:	accumulated error in the PID controller.
  * @prev_err:	error in the previous iteration of the PID controller.
  *		Used to calculate the derivative term.
  * @trip_switch_on:	first passive trip point of the thermal zone.  The
  *			governor switches on when this trip point is crossed.
+ *			If the thermal zone only has one passive trip point,
+ *			@trip_switch_on should be INVALID_TRIP.
  * @trip_max_desired_temperature:	last passive trip point of the thermal
  *					zone.  The temperature we are
  *					controlling for.
  */
 struct power_allocator_params {
+	bool allocated_tzp;
 	s64 err_integral;
 	s32 prev_err;
 	int trip_switch_on;
 	int trip_max_desired_temperature;
 };
 
+/**
+ * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone
+ * @tz: thermal zone we are operating in
+ *
+ * For thermal zones that don't provide a sustainable_power in their
+ * thermal_zone_params, estimate one.  Calculate it using the minimum
+ * power of all the cooling devices as that gives a valid value that
+ * can give some degree of functionality.  For optimal performance of
+ * this governor, provide a sustainable_power in the thermal zone's
+ * thermal_zone_params.
+ */
+static u32 estimate_sustainable_power(struct thermal_zone_device *tz)
+{
+	u32 sustainable_power = 0;
+	struct thermal_instance *instance;
+	struct power_allocator_params *params = tz->governor_data;
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		struct thermal_cooling_device *cdev = instance->cdev;
+		u32 min_power;
+
+		if (instance->trip != params->trip_max_desired_temperature)
+			continue;
+
+		if (power_actor_get_min_power(cdev, tz, &min_power))
+			continue;
+
+		sustainable_power += min_power;
+	}
+
+	return sustainable_power;
+}
+
+/**
+ * estimate_pid_constants() - Estimate the constants for the PID controller
+ * @tz:		thermal zone for which to estimate the constants
+ * @sustainable_power:	sustainable power for the thermal zone
+ * @trip_switch_on:	trip point number for the switch on temperature
+ * @control_temp:	target temperature for the power allocator governor
+ * @force:	whether to force the update of the constants
+ *
+ * This function is used to update the estimation of the PID
+ * controller constants in struct thermal_zone_parameters.
+ * Sustainable power is provided in case it was estimated.  The
+ * estimated sustainable_power should not be stored in the
+ * thermal_zone_parameters so it has to be passed explicitly to this
+ * function.
+ *
+ * If @force is not set, the values in the thermal zone's parameters
+ * are preserved if they are not zero.  If @force is set, the values
+ * in thermal zone's parameters are overwritten.
+ */
+static void estimate_pid_constants(struct thermal_zone_device *tz,
+				   u32 sustainable_power, int trip_switch_on,
+				   int control_temp, bool force)
+{
+	int ret;
+	int switch_on_temp;
+	u32 temperature_threshold;
+
+	ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp);
+	if (ret)
+		switch_on_temp = 0;
+
+	temperature_threshold = control_temp - switch_on_temp;
+
+	if (!tz->tzp->k_po || force)
+		tz->tzp->k_po = int_to_frac(sustainable_power) /
+			temperature_threshold;
+
+	if (!tz->tzp->k_pu || force)
+		tz->tzp->k_pu = int_to_frac(2 * sustainable_power) /
+			temperature_threshold;
+
+	if (!tz->tzp->k_i || force)
+		tz->tzp->k_i = int_to_frac(10) / 1000;
+	/*
+	 * The default for k_d and integral_cutoff is 0, so we can
+	 * leave them as they are.
+	 */
+}
+
 /**
  * pid_controller() - PID controller
  * @tz:	thermal zone we are operating in
@@ -98,10 +187,20 @@ static u32 pid_controller(struct thermal_zone_device *tz,
 {
 	s64 p, i, d, power_range;
 	s32 err, max_power_frac;
+	u32 sustainable_power;
 	struct power_allocator_params *params = tz->governor_data;
 
 	max_power_frac = int_to_frac(max_allocatable_power);
 
+	if (tz->tzp->sustainable_power) {
+		sustainable_power = tz->tzp->sustainable_power;
+	} else {
+		sustainable_power = estimate_sustainable_power(tz);
+		estimate_pid_constants(tz, sustainable_power,
+				       params->trip_switch_on, control_temp,
+				       true);
+	}
+
 	err = control_temp - current_temp;
 	err = int_to_frac(err);
 
@@ -139,7 +238,7 @@ static u32 pid_controller(struct thermal_zone_device *tz,
 	power_range = p + i + d;
 
 	/* feed-forward the known sustainable dissipatable power */
-	power_range = tz->tzp->sustainable_power + frac_to_int(power_range);
+	power_range = sustainable_power + frac_to_int(power_range);
 
 	power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power);
 
@@ -247,6 +346,11 @@ static int allocate_power(struct thermal_zone_device *tz,
 		}
 	}
 
+	if (!num_actors) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+
 	/*
 	 * We need to allocate five arrays of the same size:
 	 * req_power, max_power, granted_power, extra_actor_power and
@@ -340,43 +444,66 @@ static int allocate_power(struct thermal_zone_device *tz,
 	return ret;
 }
 
-static int get_governor_trips(struct thermal_zone_device *tz,
-			      struct power_allocator_params *params)
+/**
+ * get_governor_trips() - get the number of the two trip points that are key for this governor
+ * @tz:	thermal zone to operate on
+ * @params:	pointer to private data for this governor
+ *
+ * The power allocator governor works optimally with two trips points:
+ * a "switch on" trip point and a "maximum desired temperature".  These
+ * are defined as the first and last passive trip points.
+ *
+ * If there is only one trip point, then that's considered to be the
+ * "maximum desired temperature" trip point and the governor is always
+ * on.  If there are no passive or active trip points, then the
+ * governor won't do anything.  In fact, its throttle function
+ * won't be called at all.
+ */
+static void get_governor_trips(struct thermal_zone_device *tz,
+			       struct power_allocator_params *params)
 {
-	int i, ret, last_passive;
+	int i, last_active, last_passive;
 	bool found_first_passive;
 
 	found_first_passive = false;
-	last_passive = -1;
-	ret = -EINVAL;
+	last_active = INVALID_TRIP;
+	last_passive = INVALID_TRIP;
 
 	for (i = 0; i < tz->trips; i++) {
 		enum thermal_trip_type type;
+		int ret;
 
 		ret = tz->ops->get_trip_type(tz, i, &type);
-		if (ret)
-			return ret;
+		if (ret) {
+			dev_warn(&tz->device,
+				 "Failed to get trip point %d type: %d\n", i,
+				 ret);
+			continue;
+		}
 
-		if (!found_first_passive) {
-			if (type == THERMAL_TRIP_PASSIVE) {
+		if (type == THERMAL_TRIP_PASSIVE) {
+			if (!found_first_passive) {
 				params->trip_switch_on = i;
 				found_first_passive = true;
+			} else  {
+				last_passive = i;
 			}
-		} else if (type == THERMAL_TRIP_PASSIVE) {
-			last_passive = i;
+		} else if (type == THERMAL_TRIP_ACTIVE) {
+			last_active = i;
 		} else {
 			break;
 		}
 	}
 
-	if (last_passive != -1) {
+	if (last_passive != INVALID_TRIP) {
 		params->trip_max_desired_temperature = last_passive;
-		ret = 0;
+	} else if (found_first_passive) {
+		params->trip_max_desired_temperature = params->trip_switch_on;
+		params->trip_switch_on = INVALID_TRIP;
 	} else {
-		ret = -EINVAL;
+		params->trip_switch_on = INVALID_TRIP;
+		params->trip_max_desired_temperature = last_active;
 	}
-
-	return ret;
 }
 
 static void reset_pid_controller(struct power_allocator_params *params)
@@ -405,60 +532,45 @@ static void allow_maximum_power(struct thermal_zone_device *tz)
  * power_allocator_bind() - bind the power_allocator governor to a thermal zone
  * @tz:	thermal zone to bind it to
  *
- * Check that the thermal zone is valid for this governor, that is, it
- * has two thermal trips.  If so, initialize the PID controller
- * parameters and bind it to the thermal zone.
+ * Initialize the PID controller parameters and bind it to the thermal
+ * zone.
  *
- * Return: 0 on success, -EINVAL if the trips were invalid or -ENOMEM
- * if we ran out of memory.
+ * Return: 0 on success, or -ENOMEM if we ran out of memory.
  */
 static int power_allocator_bind(struct thermal_zone_device *tz)
 {
 	int ret;
 	struct power_allocator_params *params;
-	int switch_on_temp, control_temp;
-	u32 temperature_threshold;
-
-	if (!tz->tzp || !tz->tzp->sustainable_power) {
-		dev_err(&tz->device,
-			"power_allocator: missing sustainable_power\n");
-		return -EINVAL;
-	}
+	int control_temp;
 
 	params = kzalloc(sizeof(*params), GFP_KERNEL);
 	if (!params)
 		return -ENOMEM;
 
-	ret = get_governor_trips(tz, params);
-	if (ret) {
-		dev_err(&tz->device,
-			"thermal zone %s has wrong trip setup for power allocator\n",
-			tz->type);
-		goto free;
-	}
+	if (!tz->tzp) {
+		tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL);
+		if (!tz->tzp) {
+			ret = -ENOMEM;
+			goto free_params;
+		}
 
-	ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
-				     &switch_on_temp);
-	if (ret)
-		goto free;
+		params->allocated_tzp = true;
+	}
 
-	ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature,
-				     &control_temp);
-	if (ret)
-		goto free;
+	if (!tz->tzp->sustainable_power)
+		dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n");
 
-	temperature_threshold = control_temp - switch_on_temp;
+	get_governor_trips(tz, params);
 
-	tz->tzp->k_po = tz->tzp->k_po ?:
-		int_to_frac(tz->tzp->sustainable_power) / temperature_threshold;
-	tz->tzp->k_pu = tz->tzp->k_pu ?:
-		int_to_frac(2 * tz->tzp->sustainable_power) /
-		temperature_threshold;
-	tz->tzp->k_i = tz->tzp->k_i ?: int_to_frac(10) / 1000;
-	/*
-	 * The default for k_d and integral_cutoff is 0, so we can
-	 * leave them as they are.
-	 */
+	if (tz->trips > 0) {
+		ret = tz->ops->get_trip_temp(tz,
+					params->trip_max_desired_temperature,
+					&control_temp);
+		if (!ret)
+			estimate_pid_constants(tz, tz->tzp->sustainable_power,
+					       params->trip_switch_on,
+					       control_temp, false);
+	}
 
 	reset_pid_controller(params);
 
@@ -466,14 +578,23 @@ static int power_allocator_bind(struct thermal_zone_device *tz)
 
 	return 0;
 
-free:
+free_params:
 	kfree(params);
+
 	return ret;
 }
 
 static void power_allocator_unbind(struct thermal_zone_device *tz)
 {
+	struct power_allocator_params *params = tz->governor_data;
+
 	dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
+
+	if (params->allocated_tzp) {
+		kfree(tz->tzp);
+		tz->tzp = NULL;
+	}
+
 	kfree(tz->governor_data);
 	tz->governor_data = NULL;
 }
@@ -499,13 +620,7 @@ static int power_allocator_throttle(struct thermal_zone_device *tz, int trip)
 
 	ret = tz->ops->get_trip_temp(tz, params->trip_switch_on,
 				     &switch_on_temp);
-	if (ret) {
-		dev_warn(&tz->device,
-			 "Failed to get switch on temperature: %d\n", ret);
-		return ret;
-	}
-
-	if (current_temp < switch_on_temp) {
+	if (!ret && (current_temp < switch_on_temp)) {
 		tz->passive = 0;
 		reset_pid_controller(params);
 		allow_maximum_power(tz);

drivers/thermal/thermal_core.c

@@ -1012,6 +1012,34 @@ int power_actor_get_max_power(struct thermal_cooling_device *cdev,
 	return cdev->ops->state2power(cdev, tz, 0, max_power);
 }
 
+/**
+ * power_actor_get_min_power() - get the mainimum power that a cdev can consume
+ * @cdev:	pointer to &thermal_cooling_device
+ * @tz:		a valid thermal zone device pointer
+ * @min_power:	pointer in which to store the minimum power
+ *
+ * Calculate the minimum power consumption in milliwatts that the
+ * cooling device can currently consume and store it in @min_power.
+ *
+ * Return: 0 on success, -EINVAL if @cdev doesn't support the
+ * power_actor API or -E* on other error.
+ */
+int power_actor_get_min_power(struct thermal_cooling_device *cdev,
+			      struct thermal_zone_device *tz, u32 *min_power)
+{
+	unsigned long max_state;
+	int ret;
+
+	if (!cdev_is_power_actor(cdev))
+		return -EINVAL;
+
+	ret = cdev->ops->get_max_state(cdev, &max_state);
+	if (ret)
+		return ret;
+
+	return cdev->ops->state2power(cdev, tz, max_state, min_power);
+}
+
 /**
  * power_actor_set_power() - limit the maximum power that a cooling device can consume
  * @cdev:	pointer to &thermal_cooling_device

drivers/thermal/ti-soc-thermal/Kconfig

 config TI_SOC_THERMAL
 	tristate "Texas Instruments SoCs temperature sensor driver"
-	depends on THERMAL
-	depends on ARCH_HAS_BANDGAP
 	help
 	  If you say yes here you get support for the Texas Instruments
 	  OMAP4460+ on die bandgap temperature sensor support. The register
@@ -24,7 +22,7 @@ config TI_THERMAL
 config OMAP4_THERMAL
 	bool "Texas Instruments OMAP4 thermal support"
 	depends on TI_SOC_THERMAL
-	depends on ARCH_OMAP4
+	depends on ARCH_OMAP4 || COMPILE_TEST
 	help
 	  If you say yes here you get thermal support for the Texas Instruments
 	  OMAP4 SoC family. The current chip supported are:
@@ -38,7 +36,7 @@ config OMAP4_THERMAL
 config OMAP5_THERMAL
 	bool "Texas Instruments OMAP5 thermal support"
 	depends on TI_SOC_THERMAL
-	depends on SOC_OMAP5
+	depends on SOC_OMAP5 || COMPILE_TEST
 	help
 	  If you say yes here you get thermal support for the Texas Instruments
 	  OMAP5 SoC family. The current chip supported are:
@@ -50,7 +48,7 @@ config OMAP5_THERMAL
 config DRA752_THERMAL
 	bool "Texas Instruments DRA752 thermal support"
 	depends on TI_SOC_THERMAL
-	depends on SOC_DRA7XX
+	depends on SOC_DRA7XX || COMPILE_TEST
 	help
 	  If you say yes here you get thermal support for the Texas Instruments
 	  DRA752 SoC family. The current chip supported are:

include/linux/thermal.h

@@ -360,7 +360,7 @@ static inline struct thermal_zone_device *
 thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
 				const struct thermal_zone_of_device_ops *ops)
 {
-	return NULL;
+	return ERR_PTR(-ENODEV);
 }
 
 static inline
@@ -380,6 +380,8 @@ static inline bool cdev_is_power_actor(struct thermal_cooling_device *cdev)
 
 int power_actor_get_max_power(struct thermal_cooling_device *,
 			      struct thermal_zone_device *tz, u32 *max_power);
+int power_actor_get_min_power(struct thermal_cooling_device *,
+			      struct thermal_zone_device *tz, u32 *min_power);
 int power_actor_set_power(struct thermal_cooling_device *,
 			  struct thermal_instance *, u32);
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
@@ -415,6 +417,10 @@ static inline bool cdev_is_power_actor(struct thermal_cooling_device *cdev)
 static inline int power_actor_get_max_power(struct thermal_cooling_device *cdev,
 			      struct thermal_zone_device *tz, u32 *max_power)
 { return 0; }
+static inline int power_actor_get_min_power(struct thermal_cooling_device *cdev,
+					    struct thermal_zone_device *tz,
+					    u32 *min_power)
+{ return -ENODEV; }
 static inline int power_actor_set_power(struct thermal_cooling_device *cdev,
 			  struct thermal_instance *tz, u32 power)
 { return 0; }