Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal into soc-thermal

7 files changed, 1055 insertions, 28 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index f35a1f7..3feb537 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -29,6 +29,19 @@ config THERMAL_HWMON
 	  Say 'Y' here if you want all thermal sensors to
 	  have hwmon sysfs interface too.
 
+config THERMAL_OF
+	bool
+	prompt "APIs to parse thermal data out of device tree"
+	depends on OF
+	default y
+	help
+	  This options provides helpers to add the support to
+	  read and parse thermal data definitions out of the
+	  device tree blob.
+
+	  Say 'Y' here if you need to build thermal infrastructure
+	  based on device tree.
+
 choice
 	prompt "Default Thermal governor"
 	default THERMAL_DEFAULT_GOV_STEP_WISE
@@ -79,6 +92,7 @@ config THERMAL_GOV_USER_SPACE
 config CPU_THERMAL
 	bool "generic cpu cooling support"
 	depends on CPU_FREQ
+	depends on THERMAL_OF
 	help
 	  This implements the generic cpu cooling mechanism through frequency
 	  reduction. An ACPI version of this already exists
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 584b363..4b03956 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -7,6 +7,7 @@ thermal_sys-y			+= thermal_core.o
 
 # interface to/from other layers providing sensors
 thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
+thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
 
 # governors
 thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= fair_share.o
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 02a46f2..a6cb553 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -417,18 +417,21 @@ static struct notifier_block thermal_cpufreq_notifier_block = {
 };
 
 /**
- * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * __cpufreq_cooling_register - helper function to create cpufreq cooling device
+ * @np: a valid struct device_node to the cooling device device tree node
  * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
  *
  * This interface function registers the cpufreq cooling device with the name
  * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
- * cooling devices.
+ * cooling devices. It also gives the opportunity to link the cooling device
+ * with a device tree node, in order to bind it via the thermal DT code.
  *
  * Return: a valid struct thermal_cooling_device pointer on success,
  * on failure, it returns a corresponding ERR_PTR().
  */
-struct thermal_cooling_device *
-cpufreq_cooling_register(const struct cpumask *clip_cpus)
+static struct thermal_cooling_device *
+__cpufreq_cooling_register(struct device_node *np,
+			   const struct cpumask *clip_cpus)
 {
 	struct thermal_cooling_device *cool_dev;
 	struct cpufreq_cooling_device *cpufreq_dev = NULL;
@@ -467,8 +470,8 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 	snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
 		 cpufreq_dev->id);
 
-	cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev,
-						   &cpufreq_cooling_ops);
+	cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
+						      &cpufreq_cooling_ops);
 	if (IS_ERR(cool_dev)) {
 		release_idr(&cpufreq_idr, cpufreq_dev->id);
 		kfree(cpufreq_dev);
@@ -488,9 +491,50 @@ cpufreq_cooling_register(const struct cpumask *clip_cpus)
 
 	return cool_dev;
 }
+
+/**
+ * cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+cpufreq_cooling_register(const struct cpumask *clip_cpus)
+{
+	return __cpufreq_cooling_register(NULL, clip_cpus);
+}
 EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
 
 /**
+ * of_cpufreq_cooling_register - function to create cpufreq cooling device.
+ * @np: a valid struct device_node to the cooling device device tree node
+ * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
+ *
+ * This interface function registers the cpufreq cooling device with the name
+ * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
+ * cooling devices. Using this API, the cpufreq cooling device will be
+ * linked to the device tree node provided.
+ *
+ * Return: a valid struct thermal_cooling_device pointer on success,
+ * on failure, it returns a corresponding ERR_PTR().
+ */
+struct thermal_cooling_device *
+of_cpufreq_cooling_register(struct device_node *np,
+			    const struct cpumask *clip_cpus)
+{
+	if (!np)
+		return ERR_PTR(-EINVAL);
+
+	return __cpufreq_cooling_register(np, clip_cpus);
+}
+EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
+
+/**
  * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
  * @cdev: thermal cooling device pointer.
  *
diff --git a/drivers/thermal/of-thermal.c b/drivers/thermal/of-thermal.c
new file mode 100644
index 0000000..04b1be7
--- /dev/null
+++ b/drivers/thermal/of-thermal.c
@@ -0,0 +1,849 @@
+/*
+ *  of-thermal.c - Generic Thermal Management device tree support.
+ *
+ *  Copyright (C) 2013 Texas Instruments
+ *  Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com>
+ *
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <linux/thermal.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/string.h>
+
+#include "thermal_core.h"
+
+/***   Private data structures to represent thermal device tree data ***/
+
+/**
+ * struct __thermal_trip - representation of a point in temperature domain
+ * @np: pointer to struct device_node that this trip point was created from
+ * @temperature: temperature value in miliCelsius
+ * @hysteresis: relative hysteresis in miliCelsius
+ * @type: trip point type
+ */
+
+struct __thermal_trip {
+	struct device_node *np;
+	unsigned long int temperature;
+	unsigned long int hysteresis;
+	enum thermal_trip_type type;
+};
+
+/**
+ * struct __thermal_bind_param - a match between trip and cooling device
+ * @cooling_device: a pointer to identify the referred cooling device
+ * @trip_id: the trip point index
+ * @usage: the percentage (from 0 to 100) of cooling contribution
+ * @min: minimum cooling state used at this trip point
+ * @max: maximum cooling state used at this trip point
+ */
+
+struct __thermal_bind_params {
+	struct device_node *cooling_device;
+	unsigned int trip_id;
+	unsigned int usage;
+	unsigned long min;
+	unsigned long max;
+};
+
+/**
+ * struct __thermal_zone - internal representation of a thermal zone
+ * @mode: current thermal zone device mode (enabled/disabled)
+ * @passive_delay: polling interval while passive cooling is activated
+ * @polling_delay: zone polling interval
+ * @ntrips: number of trip points
+ * @trips: an array of trip points (0..ntrips - 1)
+ * @num_tbps: number of thermal bind params
+ * @tbps: an array of thermal bind params (0..num_tbps - 1)
+ * @sensor_data: sensor private data used while reading temperature and trend
+ * @get_temp: sensor callback to read temperature
+ * @get_trend: sensor callback to read temperature trend
+ */
+
+struct __thermal_zone {
+	enum thermal_device_mode mode;
+	int passive_delay;
+	int polling_delay;
+
+	/* trip data */
+	int ntrips;
+	struct __thermal_trip *trips;
+
+	/* cooling binding data */
+	int num_tbps;
+	struct __thermal_bind_params *tbps;
+
+	/* sensor interface */
+	void *sensor_data;
+	int (*get_temp)(void *, long *);
+	int (*get_trend)(void *, long *);
+};
+
+/***   DT thermal zone device callbacks   ***/
+
+static int of_thermal_get_temp(struct thermal_zone_device *tz,
+			       unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (!data->get_temp)
+		return -EINVAL;
+
+	return data->get_temp(data->sensor_data, temp);
+}
+
+static int of_thermal_get_trend(struct thermal_zone_device *tz, int trip,
+				enum thermal_trend *trend)
+{
+	struct __thermal_zone *data = tz->devdata;
+	long dev_trend;
+	int r;
+
+	if (!data->get_trend)
+		return -EINVAL;
+
+	r = data->get_trend(data->sensor_data, &dev_trend);
+	if (r)
+		return r;
+
+	/* 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;
+}
+
+static int of_thermal_bind(struct thermal_zone_device *thermal,
+			   struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to bind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_bind_cooling_device(thermal,
+						tbp->trip_id, cdev,
+						tbp->min,
+						tbp->max);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_unbind(struct thermal_zone_device *thermal,
+			     struct thermal_cooling_device *cdev)
+{
+	struct __thermal_zone *data = thermal->devdata;
+	int i;
+
+	if (!data || IS_ERR(data))
+		return -ENODEV;
+
+	/* find where to unbind */
+	for (i = 0; i < data->num_tbps; i++) {
+		struct __thermal_bind_params *tbp = data->tbps + i;
+
+		if (tbp->cooling_device == cdev->np) {
+			int ret;
+
+			ret = thermal_zone_unbind_cooling_device(thermal,
+						tbp->trip_id, cdev);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int of_thermal_get_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode *mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	*mode = data->mode;
+
+	return 0;
+}
+
+static int of_thermal_set_mode(struct thermal_zone_device *tz,
+			       enum thermal_device_mode mode)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	mutex_lock(&tz->lock);
+
+	if (mode == THERMAL_DEVICE_ENABLED)
+		tz->polling_delay = data->polling_delay;
+	else
+		tz->polling_delay = 0;
+
+	mutex_unlock(&tz->lock);
+
+	data->mode = mode;
+	thermal_zone_device_update(tz);
+
+	return 0;
+}
+
+static int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip,
+				    enum thermal_trip_type *type)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*type = data->trips[trip].type;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*temp = data->trips[trip].temperature;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip,
+				    unsigned long temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal framework should take care of data->mask & (1 << trip) */
+	data->trips[trip].temperature = temp;
+
+	return 0;
+}
+
+static int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long *hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	*hyst = data->trips[trip].hysteresis;
+
+	return 0;
+}
+
+static int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip,
+				    unsigned long hyst)
+{
+	struct __thermal_zone *data = tz->devdata;
+
+	if (trip >= data->ntrips || trip < 0)
+		return -EDOM;
+
+	/* thermal framework should take care of data->mask & (1 << trip) */
+	data->trips[trip].hysteresis = hyst;
+
+	return 0;
+}
+
+static int of_thermal_get_crit_temp(struct thermal_zone_device *tz,
+				    unsigned long *temp)
+{
+	struct __thermal_zone *data = tz->devdata;
+	int i;
+
+	for (i = 0; i < data->ntrips; i++)
+		if (data->trips[i].type == THERMAL_TRIP_CRITICAL) {
+			*temp = data->trips[i].temperature;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static struct thermal_zone_device_ops of_thermal_ops = {
+	.get_mode = of_thermal_get_mode,
+	.set_mode = of_thermal_set_mode,
+
+	.get_trip_type = of_thermal_get_trip_type,
+	.get_trip_temp = of_thermal_get_trip_temp,
+	.set_trip_temp = of_thermal_set_trip_temp,
+	.get_trip_hyst = of_thermal_get_trip_hyst,
+	.set_trip_hyst = of_thermal_set_trip_hyst,
+	.get_crit_temp = of_thermal_get_crit_temp,
+
+	.bind = of_thermal_bind,
+	.unbind = of_thermal_unbind,
+};
+
+/***   sensor API   ***/
+
+static struct thermal_zone_device *
+thermal_zone_of_add_sensor(struct device_node *zone,
+			   struct device_node *sensor, void *data,
+			   int (*get_temp)(void *, long *),
+			   int (*get_trend)(void *, long *))
+{
+	struct thermal_zone_device *tzd;
+	struct __thermal_zone *tz;
+
+	tzd = thermal_zone_get_zone_by_name(zone->name);
+	if (IS_ERR(tzd))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	tz = tzd->devdata;
+
+	mutex_lock(&tzd->lock);
+	tz->get_temp = get_temp;
+	tz->get_trend = get_trend;
+	tz->sensor_data = data;
+
+	tzd->ops->get_temp = of_thermal_get_temp;
+	tzd->ops->get_trend = of_thermal_get_trend;
+	mutex_unlock(&tzd->lock);
+
+	return tzd;
+}
+
+/**
+ * thermal_zone_of_sensor_register - registers a sensor to a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @sensor_id: a sensor identifier, in case the sensor IP has more
+ *             than one sensors
+ * @data: a private pointer (owned by the caller) that will be passed
+ *        back, when a temperature reading is needed.
+ * @get_temp: a pointer to a function that reads the sensor temperature.
+ * @get_trend: a pointer to a function that reads the sensor temperature trend.
+ *
+ * This function will search the list of thermal zones described in device
+ * tree and look for the zone that refer to the sensor device pointed by
+ * @dev->of_node as temperature providers. For the zone pointing to the
+ * sensor node, the sensor will be added to the DT thermal zone device.
+ *
+ * The thermal zone temperature is provided by the @get_temp function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * The thermal zone temperature trend is provided by the @get_trend function
+ * pointer. When called, it will have the private pointer @data back.
+ *
+ * TODO:
+ * 01 - This function must enqueue the new sensor instead of using
+ * it as the only source of temperature values.
+ *
+ * 02 - There must be a way to match the sensor with all thermal zones
+ * that refer to it.
+ *
+ * Return: On success returns a valid struct thermal_zone_device,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+struct thermal_zone_device *
+thermal_zone_of_sensor_register(struct device *dev, int sensor_id,
+				void *data, int (*get_temp)(void *, long *),
+				int (*get_trend)(void *, long *))
+{
+	struct device_node *np, *child, *sensor_np;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np)
+		return ERR_PTR(-ENODEV);
+
+	if (!dev || !dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	sensor_np = dev->of_node;
+
+	for_each_child_of_node(np, child) {
+		struct of_phandle_args sensor_specs;
+		int ret, id;
+
+		/* For now, thermal framework supports only 1 sensor per zone */
+		ret = of_parse_phandle_with_args(child, "thermal-sensors",
+						 "#thermal-sensor-cells",
+						 0, &sensor_specs);
+		if (ret)
+			continue;
+
+		if (sensor_specs.args_count >= 1) {
+			id = sensor_specs.args[0];
+			WARN(sensor_specs.args_count > 1,
+			     "%s: too many cells in sensor specifier %d\n",
+			     sensor_specs.np->name, sensor_specs.args_count);
+		} else {
+			id = 0;
+		}
+
+		if (sensor_specs.np == sensor_np && id == sensor_id) {
+			of_node_put(np);
+			return thermal_zone_of_add_sensor(child, sensor_np,
+							  data,
+							  get_temp,
+							  get_trend);
+		}
+	}
+	of_node_put(np);
+
+	return ERR_PTR(-ENODEV);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_register);
+
+/**
+ * thermal_zone_of_sensor_unregister - unregisters a sensor from a DT thermal zone
+ * @dev: a valid struct device pointer of a sensor device. Must contain
+ *       a valid .of_node, for the sensor node.
+ * @tzd: a pointer to struct thermal_zone_device where the sensor is registered.
+ *
+ * This function removes the sensor callbacks and private data from the
+ * thermal zone device registered with thermal_zone_of_sensor_register()
+ * API. It will also silent the zone by remove the .get_temp() and .get_trend()
+ * thermal zone device callbacks.
+ *
+ * TODO: When the support to several sensors per zone is added, this
+ * function must search the sensor list based on @dev parameter.
+ *
+ */
+void thermal_zone_of_sensor_unregister(struct device *dev,
+				       struct thermal_zone_device *tzd)
+{
+	struct __thermal_zone *tz;
+
+	if (!dev || !tzd || !tzd->devdata)
+		return;
+
+	tz = tzd->devdata;
+
+	/* no __thermal_zone, nothing to be done */
+	if (!tz)
+		return;
+
+	mutex_lock(&tzd->lock);
+	tzd->ops->get_temp = NULL;
+	tzd->ops->get_trend = NULL;
+
+	tz->get_temp = NULL;
+	tz->get_trend = NULL;
+	tz->sensor_data = NULL;
+	mutex_unlock(&tzd->lock);
+}
+EXPORT_SYMBOL_GPL(thermal_zone_of_sensor_unregister);
+
+/***   functions parsing device tree nodes   ***/
+
+/**
+ * thermal_of_populate_bind_params - parse and fill cooling map data
+ * @np: DT node containing a cooling-map node
+ * @__tbp: data structure to be filled with cooling map info
+ * @trips: array of thermal zone trip points
+ * @ntrips: number of trip points inside trips.
+ *
+ * This function parses a cooling-map type of node represented by
+ * @np parameter and fills the read data into @__tbp data structure.
+ * It needs the already parsed array of trip points of the thermal zone
+ * in consideration.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_bind_params(struct device_node *np,
+					   struct __thermal_bind_params *__tbp,
+					   struct __thermal_trip *trips,
+					   int ntrips)
+{
+	struct of_phandle_args cooling_spec;
+	struct device_node *trip;
+	int ret, i;
+	u32 prop;
+
+	/* Default weight. Usage is optional */
+	__tbp->usage = 0;
+	ret = of_property_read_u32(np, "contribution", &prop);
+	if (ret == 0)
+		__tbp->usage = prop;
+
+	trip = of_parse_phandle(np, "trip", 0);
+	if (!trip) {
+		pr_err("missing trip property\n");
+		return -ENODEV;
+	}
+
+	/* match using device_node */
+	for (i = 0; i < ntrips; i++)
+		if (trip == trips[i].np) {
+			__tbp->trip_id = i;
+			break;
+		}
+
+	if (i == ntrips) {
+		ret = -ENODEV;
+		goto end;
+	}
+
+	ret = of_parse_phandle_with_args(np, "cooling-device", "#cooling-cells",
+					 0, &cooling_spec);
+	if (ret < 0) {
+		pr_err("missing cooling_device property\n");
+		goto end;
+	}
+	__tbp->cooling_device = cooling_spec.np;
+	if (cooling_spec.args_count >= 2) { /* at least min and max */
+		__tbp->min = cooling_spec.args[0];
+		__tbp->max = cooling_spec.args[1];
+	} else {
+		pr_err("wrong reference to cooling device, missing limits\n");
+	}
+
+end:
+	of_node_put(trip);
+
+	return ret;
+}
+
+/**
+ * It maps 'enum thermal_trip_type' found in include/linux/thermal.h
+ * into the device tree binding of 'trip', property type.
+ */
+static const char * const trip_types[] = {
+	[THERMAL_TRIP_ACTIVE]	= "active",
+	[THERMAL_TRIP_PASSIVE]	= "passive",
+	[THERMAL_TRIP_HOT]	= "hot",
+	[THERMAL_TRIP_CRITICAL]	= "critical",
+};
+
+/**
+ * thermal_of_get_trip_type - Get phy mode for given device_node
+ * @np:	Pointer to the given device_node
+ * @type: Pointer to resulting trip type
+ *
+ * The function gets trip type string from property 'type',
+ * and store its index in trip_types table in @type,
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+static int thermal_of_get_trip_type(struct device_node *np,
+				    enum thermal_trip_type *type)
+{
+	const char *t;
+	int err, i;
+
+	err = of_property_read_string(np, "type", &t);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < ARRAY_SIZE(trip_types); i++)
+		if (!strcasecmp(t, trip_types[i])) {
+			*type = i;
+			return 0;
+		}
+
+	return -ENODEV;
+}
+
+/**
+ * thermal_of_populate_trip - parse and fill one trip point data
+ * @np: DT node containing a trip point node
+ * @trip: trip point data structure to be filled up
+ *
+ * This function parses a trip point type of node represented by
+ * @np parameter and fills the read data into @trip data structure.
+ *
+ * Return: 0 on success, proper error code otherwise
+ */
+static int thermal_of_populate_trip(struct device_node *np,
+				    struct __thermal_trip *trip)
+{
+	int prop;
+	int ret;
+
+	ret = of_property_read_u32(np, "temperature", &prop);
+	if (ret < 0) {
+		pr_err("missing temperature property\n");
+		return ret;
+	}
+	trip->temperature = prop;
+
+	ret = of_property_read_u32(np, "hysteresis", &prop);
+	if (ret < 0) {
+		pr_err("missing hysteresis property\n");
+		return ret;
+	}
+	trip->hysteresis = prop;
+
+	ret = thermal_of_get_trip_type(np, &trip->type);
+	if (ret < 0) {
+		pr_err("wrong trip type property\n");
+		return ret;
+	}
+
+	/* Required for cooling map matching */
+	trip->np = np;
+
+	return 0;
+}
+
+/**
+ * thermal_of_build_thermal_zone - parse and fill one thermal zone data
+ * @np: DT node containing a thermal zone node
+ *
+ * This function parses a thermal zone type of node represented by
+ * @np parameter and fills the read data into a __thermal_zone data structure
+ * and return this pointer.
+ *
+ * TODO: Missing properties to parse: thermal-sensor-names and coefficients
+ *
+ * Return: On success returns a valid struct __thermal_zone,
+ * otherwise, it returns a corresponding ERR_PTR(). Caller must
+ * check the return value with help of IS_ERR() helper.
+ */
+static struct __thermal_zone *
+thermal_of_build_thermal_zone(struct device_node *np)
+{
+	struct device_node *child = NULL, *gchild;
+	struct __thermal_zone *tz;
+	int ret, i;
+	u32 prop;
+
+	if (!np) {
+		pr_err("no thermal zone np\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	tz = kzalloc(sizeof(*tz), GFP_KERNEL);
+	if (!tz)
+		return ERR_PTR(-ENOMEM);
+
+	ret = of_property_read_u32(np, "polling-delay-passive", &prop);
+	if (ret < 0) {
+		pr_err("missing polling-delay-passive property\n");
+		goto free_tz;
+	}
+	tz->passive_delay = prop;
+
+	ret = of_property_read_u32(np, "polling-delay", &prop);
+	if (ret < 0) {
+		pr_err("missing polling-delay property\n");
+		goto free_tz;
+	}
+	tz->polling_delay = prop;
+
+	/* trips */
+	child = of_get_child_by_name(np, "trips");
+
+	/* No trips provided */
+	if (!child)
+		goto finish;
+
+	tz->ntrips = of_get_child_count(child);
+	if (tz->ntrips == 0) /* must have at least one child */
+		goto finish;
+
+	tz->trips = kzalloc(tz->ntrips * sizeof(*tz->trips), GFP_KERNEL);
+	if (!tz->trips) {
+		ret = -ENOMEM;
+		goto free_tz;
+	}
+
+	i = 0;
+	for_each_child_of_node(child, gchild) {
+		ret = thermal_of_populate_trip(gchild, &tz->trips[i++]);
+		if (ret)
+			goto free_trips;
+	}
+
+	of_node_put(child);
+
+	/* cooling-maps */
+	child = of_get_child_by_name(np, "cooling-maps");
+
+	/* cooling-maps not provided */
+	if (!child)
+		goto finish;
+
+	tz->num_tbps = of_get_child_count(child);
+	if (tz->num_tbps == 0)
+		goto finish;
+
+	tz->tbps = kzalloc(tz->num_tbps * sizeof(*tz->tbps), GFP_KERNEL);
+	if (!tz->tbps) {
+		ret = -ENOMEM;
+		goto free_trips;
+	}
+
+	i = 0;
+	for_each_child_of_node(child, gchild)
+		ret = thermal_of_populate_bind_params(gchild, &tz->tbps[i++],
+						      tz->trips, tz->ntrips);
+		if (ret)
+			goto free_tbps;
+
+finish:
+	of_node_put(child);
+	tz->mode = THERMAL_DEVICE_DISABLED;
+
+	return tz;
+
+free_tbps:
+	kfree(tz->tbps);
+free_trips:
+	kfree(tz->trips);
+free_tz:
+	kfree(tz);
+	of_node_put(child);
+
+	return ERR_PTR(ret);
+}
+
+static inline void of_thermal_free_zone(struct __thermal_zone *tz)
+{
+	kfree(tz->tbps);
+	kfree(tz->trips);
+	kfree(tz);
+}
+
+/**
+ * of_parse_thermal_zones - parse device tree thermal data
+ *
+ * Initialization function that can be called by machine initialization
+ * code to parse thermal data and populate the thermal framework
+ * with hardware thermal zones info. This function only parses thermal zones.
+ * Cooling devices and sensor devices nodes are supposed to be parsed
+ * by their respective drivers.
+ *
+ * Return: 0 on success, proper error code otherwise
+ *
+ */
+int __init of_parse_thermal_zones(void)
+{
+	struct device_node *np, *child;
+	struct __thermal_zone *tz;
+	struct thermal_zone_device_ops *ops;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_debug("unable to find thermal zones\n");
+		return 0; /* Run successfully on systems without thermal DT */
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+		struct thermal_zone_params *tzp;
+
+		tz = thermal_of_build_thermal_zone(child);
+		if (IS_ERR(tz)) {
+			pr_err("failed to build thermal zone %s: %ld\n",
+			       child->name,
+			       PTR_ERR(tz));
+			continue;
+		}
+
+		ops = kmemdup(&of_thermal_ops, sizeof(*ops), GFP_KERNEL);
+		if (!ops)
+			goto exit_free;
+
+		tzp = kzalloc(sizeof(*tzp), GFP_KERNEL);
+		if (!tzp) {
+			kfree(ops);
+			goto exit_free;
+		}
+
+		/* No hwmon because there might be hwmon drivers registering */
+		tzp->no_hwmon = true;
+
+		zone = thermal_zone_device_register(child->name, tz->ntrips,
+						    0, tz,
+						    ops, tzp,
+						    tz->passive_delay,
+						    tz->polling_delay);
+		if (IS_ERR(zone)) {
+			pr_err("Failed to build %s zone %ld\n", child->name,
+			       PTR_ERR(zone));
+			kfree(tzp);
+			kfree(ops);
+			of_thermal_free_zone(tz);
+			/* attempting to build remaining zones still */
+		}
+	}
+
+	return 0;
+
+exit_free:
+	of_thermal_free_zone(tz);
+
+	/* no memory available, so free what we have built */
+	of_thermal_destroy_zones();
+
+	return -ENOMEM;
+}
+
+/**
+ * of_thermal_destroy_zones - remove all zones parsed and allocated resources
+ *
+ * Finds all zones parsed and added to the thermal framework and remove them
+ * from the system, together with their resources.
+ *
+ */
+void of_thermal_destroy_zones(void)
+{
+	struct device_node *np, *child;
+
+	np = of_find_node_by_name(NULL, "thermal-zones");
+	if (!np) {
+		pr_err("unable to find thermal zones\n");
+		return;
+	}
+
+	for_each_child_of_node(np, child) {
+		struct thermal_zone_device *zone;
+
+		zone = thermal_zone_get_zone_by_name(child->name);
+		if (IS_ERR(zone))
+			continue;
+
+		thermal_zone_device_unregister(zone);
+		kfree(zone->tzp);
+		kfree(zone->ops);
+		of_thermal_free_zone(zone->devdata);
+	}
+}
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index f1d511a..e381d52 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -34,6 +34,7 @@
 #include <linux/thermal.h>
 #include <linux/reboot.h>
 #include <linux/string.h>
+#include <linux/of.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
 
@@ -403,7 +404,7 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
 	enum thermal_trip_type type;
 #endif
 
-	if (!tz || IS_ERR(tz))
+	if (!tz || IS_ERR(tz) || !tz->ops->get_temp)
 		goto exit;
 
 	mutex_lock(&tz->lock);
@@ -456,6 +457,9 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
 {
 	int count;
 
+	if (!tz->ops->get_temp)
+		return;
+
 	update_temperature(tz);
 
 	for (count = 0; count < tz->trips; count++)
@@ -1052,7 +1056,8 @@ static struct class thermal_class = {
 };
 
 /**
- * thermal_cooling_device_register() - register a new thermal cooling device
+ * __thermal_cooling_device_register() - register a new thermal cooling device
+ * @np:		a pointer to a device tree node.
  * @type:	the thermal cooling device type.
  * @devdata:	device private data.
  * @ops:		standard thermal cooling devices callbacks.
@@ -1060,13 +1065,16 @@ static struct class thermal_class = {
  * This interface function adds a new thermal cooling device (fan/processor/...)
  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
  * to all the thermal zone devices registered at the same time.
+ * It also gives the opportunity to link the cooling device to a device tree
+ * node, so that it can be bound to a thermal zone created out of device tree.
  *
  * Return: a pointer to the created struct thermal_cooling_device or an
  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
  */
-struct thermal_cooling_device *
-thermal_cooling_device_register(char *type, void *devdata,
-				const struct thermal_cooling_device_ops *ops)
+static struct thermal_cooling_device *
+__thermal_cooling_device_register(struct device_node *np,
+				  char *type, void *devdata,
+				  const struct thermal_cooling_device_ops *ops)
 {
 	struct thermal_cooling_device *cdev;
 	int result;
@@ -1091,6 +1099,7 @@ thermal_cooling_device_register(char *type, void *devdata,
 	strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
 	mutex_init(&cdev->lock);
 	INIT_LIST_HEAD(&cdev->thermal_instances);
+	cdev->np = np;
 	cdev->ops = ops;
 	cdev->updated = true;
 	cdev->device.class = &thermal_class;
@@ -1133,9 +1142,53 @@ unregister:
 	device_unregister(&cdev->device);
 	return ERR_PTR(result);
 }
+
+/**
+ * thermal_cooling_device_register() - register a new thermal cooling device
+ * @type:	the thermal cooling device type.
+ * @devdata:	device private data.
+ * @ops:		standard thermal cooling devices callbacks.
+ *
+ * This interface function adds a new thermal cooling device (fan/processor/...)
+ * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+ * to all the thermal zone devices registered at the same time.
+ *
+ * Return: a pointer to the created struct thermal_cooling_device or an
+ * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
+ */
+struct thermal_cooling_device *
+thermal_cooling_device_register(char *type, void *devdata,
+				const struct thermal_cooling_device_ops *ops)
+{
+	return __thermal_cooling_device_register(NULL, type, devdata, ops);
+}
 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
 
 /**
+ * thermal_of_cooling_device_register() - register an OF thermal cooling device
+ * @np:		a pointer to a device tree node.
+ * @type:	the thermal cooling device type.
+ * @devdata:	device private data.
+ * @ops:		standard thermal cooling devices callbacks.
+ *
+ * This function will register a cooling device with device tree node reference.
+ * This interface function adds a new thermal cooling device (fan/processor/...)
+ * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+ * to all the thermal zone devices registered at the same time.
+ *
+ * Return: a pointer to the created struct thermal_cooling_device or an
+ * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
+ */
+struct thermal_cooling_device *
+thermal_of_cooling_device_register(struct device_node *np,
+				   char *type, void *devdata,
+				   const struct thermal_cooling_device_ops *ops)
+{
+	return __thermal_cooling_device_register(np, type, devdata, ops);
+}
+EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
+
+/**
  * thermal_cooling_device_unregister - removes the registered thermal cooling device
  * @cdev:	the thermal cooling device to remove.
  *
@@ -1370,7 +1423,7 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
  */
 struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int trips, int mask, void *devdata,
-	const struct thermal_zone_device_ops *ops,
+	struct thermal_zone_device_ops *ops,
 	const struct thermal_zone_params *tzp,
 	int passive_delay, int polling_delay)
 {
@@ -1386,7 +1439,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips)
 		return ERR_PTR(-EINVAL);
 
-	if (!ops || !ops->get_temp)
+	if (!ops)
 		return ERR_PTR(-EINVAL);
 
 	if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
@@ -1490,6 +1543,9 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 
 	INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);
 
+	if (!tz->ops->get_temp)
+		thermal_zone_device_set_polling(tz, 0);
+
 	thermal_zone_device_update(tz);
 
 	if (!result)
@@ -1740,8 +1796,14 @@ static int __init thermal_init(void)
 	if (result)
 		goto unregister_class;
 
+	result = of_parse_thermal_zones();
+	if (result)
+		goto exit_netlink;
+
 	return 0;
 
+exit_netlink:
+	genetlink_exit();
 unregister_governors:
 	thermal_unregister_governors();
 unregister_class:
@@ -1757,6 +1819,7 @@ error:
 
 static void __exit thermal_exit(void)
 {
+	of_thermal_destroy_zones();
 	genetlink_exit();
 	class_unregister(&thermal_class);
 	thermal_unregister_governors();
diff --git a/drivers/thermal/thermal_core.h b/drivers/thermal/thermal_core.h
index 7cf2f66..3db339f 100644
--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h
@@ -77,4 +77,13 @@ static inline int thermal_gov_user_space_register(void) { return 0; }
 static inline void thermal_gov_user_space_unregister(void) {}
 #endif /* CONFIG_THERMAL_GOV_USER_SPACE */
 
+/* device tree support */
+#ifdef CONFIG_THERMAL_OF
+int of_parse_thermal_zones(void);
+void of_thermal_destroy_zones(void);
+#else
+static inline int of_parse_thermal_zones(void) { return 0; }
+static inline void of_thermal_destroy_zones(void) { }
+#endif
+
 #endif /* __THERMAL_CORE_H__ */
diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
index 5a47cc8..9eec26d 100644
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -31,6 +31,7 @@
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
 #include <linux/cpu_cooling.h>
+#include <linux/of.h>
 
 #include "ti-thermal.h"
 #include "ti-bandgap.h"
@@ -44,6 +45,7 @@ struct ti_thermal_data {
 	enum thermal_device_mode mode;
 	struct work_struct thermal_wq;
 	int sensor_id;
+	bool our_zone;
 };
 
 static void ti_thermal_work(struct work_struct *work)
@@ -75,11 +77,10 @@ static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
 
 /* thermal zone ops */
 /* Get temperature callback function for thermal zone*/
-static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
-				      unsigned long *temp)
+static inline int __ti_thermal_get_temp(void *devdata, long *temp)
 {
 	struct thermal_zone_device *pcb_tz = NULL;
-	struct ti_thermal_data *data = thermal->devdata;
+	struct ti_thermal_data *data = devdata;
 	struct ti_bandgap *bgp;
 	const struct ti_temp_sensor *s;
 	int ret, tmp, slope, constant;
@@ -118,6 +119,14 @@ static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
 	return ret;
 }
 
+static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
+				      unsigned long *temp)
+{
+	struct ti_thermal_data *data = thermal->devdata;
+
+	return __ti_thermal_get_temp(data, temp);
+}
+
 /* Bind callback functions for thermal zone */
 static int ti_thermal_bind(struct thermal_zone_device *thermal,
 			   struct thermal_cooling_device *cdev)
@@ -230,11 +239,9 @@ static int ti_thermal_get_trip_temp(struct thermal_zone_device *thermal,
 	return 0;
 }
 
-/* Get the temperature trend callback functions for thermal zone */
-static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
-				int trip, enum thermal_trend *trend)
+static int __ti_thermal_get_trend(void *p, long *trend)
 {
-	struct ti_thermal_data *data = thermal->devdata;
+	struct ti_thermal_data *data = p;
 	struct ti_bandgap *bgp;
 	int id, tr, ret = 0;
 
@@ -245,6 +252,22 @@ static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
 	if (ret)
 		return ret;
 
+	*trend = tr;
+
+	return 0;
+}
+
+/* Get the temperature trend callback functions for thermal zone */
+static int ti_thermal_get_trend(struct thermal_zone_device *thermal,
+				int trip, enum thermal_trend *trend)
+{
+	int ret;
+	long tr;
+
+	ret = __ti_thermal_get_trend(thermal->devdata, &tr);
+	if (ret)
+		return ret;
+
 	if (tr > 0)
 		*trend = THERMAL_TREND_RAISING;
 	else if (tr < 0)
@@ -308,16 +331,23 @@ int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
 	if (!data)
 		return -EINVAL;
 
-	/* Create thermal zone */
-	data->ti_thermal = thermal_zone_device_register(domain,
+	/* in case this is specified by DT */
+	data->ti_thermal = thermal_zone_of_sensor_register(bgp->dev, id,
+					data, __ti_thermal_get_temp,
+					__ti_thermal_get_trend);
+	if (IS_ERR(data->ti_thermal)) {
+		/* Create thermal zone */
+		data->ti_thermal = thermal_zone_device_register(domain,
 				OMAP_TRIP_NUMBER, 0, data, &ti_thermal_ops,
 				NULL, FAST_TEMP_MONITORING_RATE,
 				FAST_TEMP_MONITORING_RATE);
-	if (IS_ERR(data->ti_thermal)) {
-		dev_err(bgp->dev, "thermal zone device is NULL\n");
-		return PTR_ERR(data->ti_thermal);
+		if (IS_ERR(data->ti_thermal)) {
+			dev_err(bgp->dev, "thermal zone device is NULL\n");
+			return PTR_ERR(data->ti_thermal);
+		}
+		data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
+		data->our_zone = true;
 	}
-	data->ti_thermal->polling_delay = FAST_TEMP_MONITORING_RATE;
 	ti_bandgap_set_sensor_data(bgp, id, data);
 	ti_bandgap_write_update_interval(bgp, data->sensor_id,
 					data->ti_thermal->polling_delay);
@@ -331,7 +361,13 @@ int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
 
-	thermal_zone_device_unregister(data->ti_thermal);
+	if (data && data->ti_thermal) {
+		if (data->our_zone)
+			thermal_zone_device_unregister(data->ti_thermal);
+		else
+			thermal_zone_of_sensor_unregister(bgp->dev,
+							  data->ti_thermal);
+	}
 
 	return 0;
 }
@@ -350,6 +386,15 @@ int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
 {
 	struct ti_thermal_data *data;
+	struct device_node *np = bgp->dev->of_node;
+
+	/*
+	 * We are assuming here that if one deploys the zone
+	 * using DT, then it must be aware that the cooling device
+	 * loading has to happen via cpufreq driver.
+	 */
+	if (of_find_property(np, "#thermal-sensor-cells", NULL))
+		return 0;
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
 	if (!data || IS_ERR(data))
@@ -380,7 +425,9 @@ int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
 	struct ti_thermal_data *data;
 
 	data = ti_bandgap_get_sensor_data(bgp, id);
-	cpufreq_cooling_unregister(data->cool_dev);
+
+	if (data && data->cool_dev)
+		cpufreq_cooling_unregister(data->cool_dev);
 
 	return 0;
 }