[PATCHv2 00/14] Thermal Framework Enhancements

@@ -29,6 +29,23 @@
 #include <linux/device.h>
 #include <linux/workqueue.h>
 
+#define THERMAL_TRIPS_NONE	-1
+#define THERMAL_MAX_TRIPS	12
+#define THERMAL_NAME_LENGTH	20
+
+/* No upper/lower limit requirement */
+#define THERMAL_NO_LIMIT	-1UL
+
+/* Unit conversion macros */
+#define KELVIN_TO_CELSIUS(t)	(long)(((long)t-2732 >= 0) ?	\
+				((long)t-2732+5)/10 : ((long)t-2732-5)/10)
+#define CELSIUS_TO_KELVIN(t)	((t)*10+2732)
+
+/* Adding event notification support elements */
+#define THERMAL_GENL_FAMILY_NAME                "thermal_event"
+#define THERMAL_GENL_VERSION                    0x01
+#define THERMAL_GENL_MCAST_GROUP_NAME           "thermal_mc_group"
+
 struct thermal_zone_device;
 struct thermal_cooling_device;
 

@@ -50,6 +67,30 @@ enum thermal_trend {
 	THERMAL_TREND_DROPPING, /* temperature is dropping */
 };
 
+/* Events supported by Thermal Netlink */
+enum events {
+	THERMAL_AUX0,
+	THERMAL_AUX1,
+	THERMAL_CRITICAL,
+	THERMAL_DEV_FAULT,
+};
+
+/* attributes of thermal_genl_family */
+enum {
+	THERMAL_GENL_ATTR_UNSPEC,
+	THERMAL_GENL_ATTR_EVENT,
+	__THERMAL_GENL_ATTR_MAX,
+};
+#define THERMAL_GENL_ATTR_MAX (__THERMAL_GENL_ATTR_MAX - 1)
+
+/* commands supported by the thermal_genl_family */
+enum {
+	THERMAL_GENL_CMD_UNSPEC,
+	THERMAL_GENL_CMD_EVENT,
+	__THERMAL_GENL_CMD_MAX,
+};
+#define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)
+
 struct thermal_zone_device_ops {
 	int (*bind) (struct thermal_zone_device *,
 		     struct thermal_cooling_device *);

@@ -83,11 +124,6 @@ struct thermal_cooling_device_ops {
 	int (*set_cur_state) (struct thermal_cooling_device *, unsigned long);
 };
 
-#define THERMAL_NO_LIMIT -1UL /* no upper/lower limit requirement */
-
-#define THERMAL_TRIPS_NONE -1
-#define THERMAL_MAX_TRIPS 12
-#define THERMAL_NAME_LENGTH 20
 struct thermal_cooling_device {
 	int id;
 	char type[THERMAL_NAME_LENGTH];

@@ -100,10 +136,6 @@ struct thermal_cooling_device {
 	struct list_head node;
 };
 
-#define KELVIN_TO_CELSIUS(t)	(long)(((long)t-2732 >= 0) ?	\
-				((long)t-2732+5)/10 : ((long)t-2732-5)/10)
-#define CELSIUS_TO_KELVIN(t)	((t)*10+2732)
-
 struct thermal_attr {
 	struct device_attribute attr;
 	char name[THERMAL_NAME_LENGTH];

@@ -131,38 +163,13 @@ struct thermal_zone_device {
 	struct list_head node;
 	struct delayed_work poll_queue;
 };
-/* Adding event notification support elements */
-#define THERMAL_GENL_FAMILY_NAME                "thermal_event"
-#define THERMAL_GENL_VERSION                    0x01
-#define THERMAL_GENL_MCAST_GROUP_NAME           "thermal_mc_group"
-
-enum events {
-	THERMAL_AUX0,
-	THERMAL_AUX1,
-	THERMAL_CRITICAL,
-	THERMAL_DEV_FAULT,
-};
 
 struct thermal_genl_event {
 	u32 orig;
 	enum events event;
 };
-/* attributes of thermal_genl_family */
-enum {
-	THERMAL_GENL_ATTR_UNSPEC,
-	THERMAL_GENL_ATTR_EVENT,
-	__THERMAL_GENL_ATTR_MAX,
-};
-#define THERMAL_GENL_ATTR_MAX (__THERMAL_GENL_ATTR_MAX - 1)
-
-/* commands supported by the thermal_genl_family */
-enum {
-	THERMAL_GENL_CMD_UNSPEC,
-	THERMAL_GENL_CMD_EVENT,
-	__THERMAL_GENL_CMD_MAX,
-};
-#define THERMAL_GENL_CMD_MAX (__THERMAL_GENL_CMD_MAX - 1)
 
+/* Function declarations */
 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
 		void *, const struct thermal_zone_device_ops *, int, int);
 void thermal_zone_device_unregister(struct thermal_zone_device *);

@@ -173,6 +180,7 @@ 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 *);
+
 struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
 		const struct thermal_cooling_device_ops *);
 void thermal_cooling_device_unregister(struct thermal_cooling_device *);

@@ -0,0 +1,53 @@
+/*
+ *  thermal_core.h
+ *
+ *  Copyright (C) 2012  Intel Corp
+ *  Author: Durgadoss R <durgadoss.r@intel.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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#ifndef __THERMAL_CORE_H__
+#define __THERMAL_CORE_H__
+
+#include <linux/device.h>
+#include <linux/thermal.h>
+
+/* Initial state of a cooling device during binding */
+#define THERMAL_NO_TARGET -1UL
+
+/*
+ * This structure is used to describe the behavior of
+ * a certain cooling device on a certain trip point
+ * in a certain thermal zone
+ */
+struct thermal_instance {
+	int id;
+	char name[THERMAL_NAME_LENGTH];
+	struct thermal_zone_device *tz;
+	struct thermal_cooling_device *cdev;
+	int trip;
+	unsigned long upper;	/* Highest cooling state for this trip point */
+	unsigned long lower;	/* Lowest cooling state for this trip point */
+	unsigned long target;	/* expected cooling state */
+	char attr_name[THERMAL_NAME_LENGTH];
+	struct device_attribute attr;
+	struct list_head tz_node; /* node in tz->thermal_instances */
+	struct list_head cdev_node; /* node in cdev->thermal_instances */
+};
+
+#endif /* __THERMAL_CORE_H__ */

@@ -37,31 +37,12 @@
 #include <net/netlink.h>
 #include <net/genetlink.h>
 
+#include "thermal_core.h"
+
 MODULE_AUTHOR("Zhang Rui");
 MODULE_DESCRIPTION("Generic thermal management sysfs support");
 MODULE_LICENSE("GPL");
 
-#define THERMAL_NO_TARGET -1UL
-/*
- * This structure is used to describe the behavior of
- * a certain cooling device on a certain trip point
- * in a certain thermal zone
- */
-struct thermal_instance {
-	int id;
-	char name[THERMAL_NAME_LENGTH];
-	struct thermal_zone_device *tz;
-	struct thermal_cooling_device *cdev;
-	int trip;
-	unsigned long upper;	/* Highest cooling state for this trip point */
-	unsigned long lower;	/* Lowest cooling state for this trip point */
-	unsigned long target;	/* expected cooling state */
-	char attr_name[THERMAL_NAME_LENGTH];
-	struct device_attribute attr;
-	struct list_head tz_node; /* node in tz->thermal_instances */
-	struct list_head cdev_node; /* node in cdev->thermal_instances */
-};
-
 static DEFINE_IDR(thermal_tz_idr);
 static DEFINE_IDR(thermal_cdev_idr);
 static DEFINE_MUTEX(thermal_idr_lock);

@@ -82,6 +82,46 @@ static void release_idr(struct idr *idr, struct mutex *lock, int id)
 		mutex_unlock(lock);
 }
 
+int get_tz_trend(struct thermal_zone_device *tz, int trip)
+{
+	enum thermal_trend trend;
+
+	if (!tz->ops->get_trend || tz->ops->get_trend(tz, trip, &trend)) {
+		if (tz->temperature > tz->last_temperature)
+			trend = THERMAL_TREND_RAISING;
+		else if (tz->temperature < tz->last_temperature)
+			trend = THERMAL_TREND_DROPPING;
+		else
+			trend = THERMAL_TREND_STABLE;
+	}
+
+	return trend;
+}
+EXPORT_SYMBOL(get_tz_trend);
+
+struct thermal_instance *get_thermal_instance(struct thermal_zone_device *tz,
+			struct thermal_cooling_device *cdev, int trip)
+{
+	struct thermal_instance *pos = NULL;
+	struct thermal_instance *target_instance = NULL;
+
+	mutex_lock(&tz->lock);
+	mutex_lock(&cdev->lock);
+
+	list_for_each_entry(pos, &tz->thermal_instances, tz_node) {
+		if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
+			target_instance = pos;
+			break;
+		}
+	}
+
+	mutex_unlock(&cdev->lock);
+	mutex_unlock(&tz->lock);
+
+	return target_instance;
+}
+EXPORT_SYMBOL(get_thermal_instance);
+
 /* sys I/F for thermal zone */
 
 #define to_thermal_zone(_dev) \

@@ -185,6 +185,10 @@ struct thermal_cooling_device *thermal_cooling_device_register(char *, void *,
 		const struct thermal_cooling_device_ops *);
 void thermal_cooling_device_unregister(struct thermal_cooling_device *);
 
+int get_tz_trend(struct thermal_zone_device *, int);
+struct thermal_instance *get_thermal_instance(struct thermal_zone_device *,
+		struct thermal_cooling_device *, int);
+
 #ifdef CONFIG_NET
 extern int thermal_generate_netlink_event(u32 orig, enum events event);
 #else

@@ -51,6 +51,9 @@ static LIST_HEAD(thermal_tz_list);
 static LIST_HEAD(thermal_cdev_list);
 static DEFINE_MUTEX(thermal_list_lock);
 
+int (*get_platform_thermal_params)(struct thermal_zone_device *);
+EXPORT_SYMBOL(get_platform_thermal_params);
+
 static int get_idr(struct idr *idr, struct mutex *lock, int *id)
 {
 	int err;

@@ -67,6 +67,12 @@ enum thermal_trend {
 	THERMAL_TREND_DROPPING, /* temperature is dropping */
 };
 
+enum thermal_throttle_policy {
+	THERMAL_USER_SPACE,
+	THERMAL_FAIR_SHARE,
+	THERMAL_STEP_WISE,
+};
+
 /* Events supported by Thermal Netlink */
 enum events {
 	THERMAL_AUX0,

@@ -162,6 +168,37 @@ struct thermal_zone_device {
 	struct mutex lock; /* protect thermal_instances list */
 	struct list_head node;
 	struct delayed_work poll_queue;
+	struct thermal_zone_params *tzp;
+};
+
+/* Structure that holds binding parameters for a zone */
+struct thermal_bind_params {
+	struct thermal_cooling_device *cdev;
+
+	/*
+	 * This is a measure of 'how effectively these devices can
+	 * cool 'this' thermal zone. The shall be determined by platform
+	 * characterization. This is on a 'percentage' scale.
+	 * See Documentation/thermal/sysfs-api.txt for more information.
+	 */
+	int weight;
+
+	/*
+	 * This is a bit mask that gives the binding relation between this
+	 * thermal zone and cdev, for a particular trip point.
+	 * See Documentation/thermal/sysfs-api.txt for more information.
+	 */
+	int trip_mask;
+	int (*match) (struct thermal_zone_device *tz,
+			struct thermal_cooling_device *cdev);
+};
+
+/* Structure to define Thermal Zone parameters */
+struct thermal_zone_params {
+	const char *zone_name;
+	enum thermal_throttle_policy throttle_policy;
+	int num_tbps;	/* Number of tbp entries */
+	struct thermal_bind_params *tbp;
 };
 
 struct thermal_genl_event {

@@ -188,6 +225,15 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *);
 int get_tz_trend(struct thermal_zone_device *, int);
 struct thermal_instance *get_thermal_instance(struct thermal_zone_device *,
 		struct thermal_cooling_device *, int);
+/*
+ * The platform layer shall define a 'function' that provides the
+ * parameters for all thermal zones in the platform. This pointer
+ * should point to that 'function'.
+ *
+ * In thermal_zone_device_register() we update the parameters
+ * for the particular thermal zone.
+ */
+extern int (*get_platform_thermal_params)(struct thermal_zone_device *);
 
 #ifdef CONFIG_NET
 extern int thermal_generate_netlink_event(u32 orig, enum events event);

@@ -1339,6 +1339,22 @@ static void remove_trip_attrs(struct thermal_zone_device *tz)
 	kfree(tz->trip_hyst_attrs);
 }
 
+static int retrieve_zone_params(struct thermal_zone_device *tz)
+{
+	int ret;
+
+	/* Check whether the platform data pointer is defined */
+	if (!get_platform_thermal_params)
+		return 0;
+
+	/* It is not an error to not have any platform data */
+	ret = get_platform_thermal_params(tz);
+	if (ret)
+		tz->tzp = NULL;
+
+	return 0;
+}
+
 /**
  * thermal_zone_device_register - register a new thermal zone device
  * @type:	the thermal zone device type

@@ -1443,6 +1459,11 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	if (result)
 		goto unregister;
 
+	/* Retrieve platform level parameters for this zone */
+	result = retrieve_zone_params(tz);
+	if (result)
+		goto unregister;
+
 	mutex_lock(&thermal_list_lock);
 	list_add_tail(&tz->node, &thermal_tz_list);
 	if (ops->bind)

@@ -378,10 +378,32 @@ passive_show(struct device *dev, struct device_attribute *attr,
 	return sprintf(buf, "%d\n", tz->forced_passive);
 }
 
+static ssize_t
+policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct thermal_zone_device *tz = to_thermal_zone(dev);
+	struct thermal_zone_params *tzp = tz->tzp;
+
+	if (!tzp)
+		return sprintf(buf, "step_wise(default)\n");
+
+	switch (tzp->throttle_policy) {
+	case THERMAL_FAIR_SHARE:
+		return sprintf(buf, "fair_share\n");
+	case THERMAL_STEP_WISE:
+		return sprintf(buf, "step_wise\n");
+	case THERMAL_USER_SPACE:
+		return sprintf(buf, "user_space\n");
+	default:
+		return sprintf(buf, "unknown\n");
+	}
+}
+
 static DEVICE_ATTR(type, 0444, type_show, NULL);
 static DEVICE_ATTR(temp, 0444, temp_show, NULL);
 static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
 static DEVICE_ATTR(passive, S_IRUGO | S_IWUSR, passive_show, passive_store);
+static DEVICE_ATTR(throttle_policy, S_IRUGO, policy_show, NULL);
 
 /* sys I/F for cooling device */
 #define to_cooling_device(_dev)	\

@@ -1349,10 +1371,16 @@ static int retrieve_zone_params(struct thermal_zone_device *tz)
 
 	/* It is not an error to not have any platform data */
 	ret = get_platform_thermal_params(tz);
-	if (ret)
+	if (ret) {
 		tz->tzp = NULL;
+		return 0;
+	}
 
-	return 0;
+	ret = device_create_file(&tz->device, &dev_attr_throttle_policy);
+	if (ret)
+		dev_err(&tz->device, "creating policy attr failed:%d\n", ret);
+
+	return ret;
 }
 
 /**

@@ -125,6 +125,111 @@ struct thermal_instance *get_thermal_instance(struct thermal_zone_device *tz,
 }
 EXPORT_SYMBOL(get_thermal_instance);
 
+static void print_bind_err_msg(struct thermal_zone_device *tz,
+			struct thermal_cooling_device *cdev, int ret)
+{
+	dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
+				tz->type, cdev->type, ret);
+}
+
+static void __bind(struct thermal_zone_device *tz, int mask,
+			struct thermal_cooling_device *cdev)
+{
+	int i, ret;
+
+	for (i = 0; i < tz->trips; i++) {
+		if (mask & (1 << i)) {
+			ret = thermal_zone_bind_cooling_device(tz, i, cdev,
+					THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
+			if (ret)
+				print_bind_err_msg(tz, cdev, ret);
+		}
+	}
+}
+
+static void __unbind(struct thermal_zone_device *tz, int mask,
+			struct thermal_cooling_device *cdev)
+{
+	int i;
+
+	for (i = 0; i < tz->trips; i++)
+		if (mask & (1 << i))
+			thermal_zone_unbind_cooling_device(tz, i, cdev);
+}
+
+static void update_bind_info(struct thermal_cooling_device *cdev)
+{
+	int i, ret;
+	struct thermal_zone_params *tzp;
+	struct thermal_zone_device *pos = NULL;
+
+	mutex_lock(&thermal_list_lock);
+
+	list_for_each_entry(pos, &thermal_tz_list, node) {
+		if (!pos->tzp && !pos->ops->bind)
+			continue;
+
+		if (!pos->tzp && pos->ops->bind) {
+			ret = pos->ops->bind(pos, cdev);
+			if (ret)
+				print_bind_err_msg(pos, cdev, ret);
+		}
+
+		tzp = pos->tzp;
+		if (!tzp->tbp)
+			return;
+
+		for (i = 0; i < tzp->num_tbps; i++) {
+			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
+				continue;
+			if (tzp->tbp[i].match(pos, cdev))
+				continue;
+			tzp->tbp[i].cdev = cdev;
+			__bind(pos, tzp->tbp[i].trip_mask, cdev);
+		}
+	}
+
+	mutex_unlock(&thermal_list_lock);
+}
+
+static void do_binding(struct thermal_zone_device *tz)
+{
+	int i, ret;
+	struct thermal_cooling_device *pos = NULL;
+	struct thermal_zone_params *tzp = tz->tzp;
+
+	if (!tzp && !tz->ops->bind)
+		return;
+
+	mutex_lock(&thermal_list_lock);
+
+	/* If there is no platform data, try to use ops->bind */
+	if (!tzp && tz->ops->bind) {
+		list_for_each_entry(pos, &thermal_cdev_list, node) {
+			ret = tz->ops->bind(tz, pos);
+			if (ret)
+				print_bind_err_msg(tz, pos, ret);
+		}
+		goto exit;
+	}
+
+	if (!tzp->tbp)
+		goto exit;
+
+	list_for_each_entry(pos, &thermal_cdev_list, node) {
+		for (i = 0; i < tzp->num_tbps; i++) {
+			if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
+				continue;
+			if (tzp->tbp[i].match(tz, pos))
+				continue;
+			tzp->tbp[i].cdev = pos;
+			__bind(tz, tzp->tbp[i].trip_mask, pos);
+		}
+	}
+exit:
+	mutex_unlock(&thermal_list_lock);
+}
+
 /* sys I/F for thermal zone */
 
 #define to_thermal_zone(_dev) \

@@ -943,7 +1048,6 @@ thermal_cooling_device_register(char *type, void *devdata,
 				const struct thermal_cooling_device_ops *ops)
 {
 	struct thermal_cooling_device *cdev;
-	struct thermal_zone_device *pos;
 	int result;
 
 	if (strlen(type) >= THERMAL_NAME_LENGTH)

@@ -993,20 +1097,15 @@ thermal_cooling_device_register(char *type, void *devdata,
 	if (result)
 		goto unregister;
 
+	/* Add 'this' new cdev to the global cdev list */
 	mutex_lock(&thermal_list_lock);
 	list_add(&cdev->node, &thermal_cdev_list);
-	list_for_each_entry(pos, &thermal_tz_list, node) {
-		if (!pos->ops->bind)
-			continue;
-		result = pos->ops->bind(pos, cdev);
-		if (result)
-			break;
-
-	}
 	mutex_unlock(&thermal_list_lock);
 
-	if (!result)
-		return cdev;
+	/* Update binding information for 'this' new cdev */
+	update_bind_info(cdev);
+
+	return cdev;
 
 unregister:
 	release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);

@@ -1022,10 +1121,10 @@ EXPORT_SYMBOL(thermal_cooling_device_register);
  * thermal_cooling_device_unregister() must be called when the device is no
  * longer needed.
  */
-void thermal_cooling_device_unregister(struct
-				       thermal_cooling_device
-				       *cdev)
+void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
 {
+	int i;
+	struct thermal_zone_params *tzp;
 	struct thermal_zone_device *tz;
 	struct thermal_cooling_device *pos = NULL;
 

@@ -1042,12 +1141,28 @@ void thermal_cooling_device_unregister(struct
 		return;
 	}
 	list_del(&cdev->node);
+
+	/* Unbind all thermal zones associated with 'this' cdev */
 	list_for_each_entry(tz, &thermal_tz_list, node) {
-		if (!tz->ops->unbind)
+		if (tz->ops->unbind) {
+			tz->ops->unbind(tz, cdev);
 			continue;
-		tz->ops->unbind(tz, cdev);
+		}
+
+		if (!tz->tzp || !tz->tzp->tbp)
+			continue;
+
+		tzp = tz->tzp;
+		for (i = 0; i < tzp->num_tbps; i++) {
+			if (tzp->tbp[i].cdev == cdev) {
+				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
+				tzp->tbp[i].cdev = NULL;
+			}
+		}
 	}
+
 	mutex_unlock(&thermal_list_lock);
+
 	if (cdev->type[0])
 		device_remove_file(&cdev->device, &dev_attr_cdev_type);
 	device_remove_file(&cdev->device, &dev_attr_max_state);

@@ -1405,7 +1520,6 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 	int passive_delay, int polling_delay)
 {
 	struct thermal_zone_device *tz;
-	struct thermal_cooling_device *pos;
 	enum thermal_trip_type trip_type;
 	int result;
 	int count;

@@ -1494,14 +1608,12 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
 
 	mutex_lock(&thermal_list_lock);
 	list_add_tail(&tz->node, &thermal_tz_list);
-	if (ops->bind)
-		list_for_each_entry(pos, &thermal_cdev_list, node) {
-		result = ops->bind(tz, pos);
-		if (result)
-			break;
-		}
 	mutex_unlock(&thermal_list_lock);
 
+	/* Bind cooling devices for this zone */
+	do_binding(tz);
+
+
 	INIT_DELAYED_WORK(&(tz->poll_queue), thermal_zone_device_check);
 
 	thermal_zone_device_update(tz);

@@ -1522,12 +1634,16 @@ EXPORT_SYMBOL(thermal_zone_device_register);
  */
 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 {
+	int i;
+	struct thermal_zone_params *tzp;
 	struct thermal_cooling_device *cdev;
 	struct thermal_zone_device *pos = NULL;
 
 	if (!tz)
 		return;
 
+	tzp = tz->tzp;
+
 	mutex_lock(&thermal_list_lock);
 	list_for_each_entry(pos, &thermal_tz_list, node)
 	    if (pos == tz)

@@ -1538,9 +1654,25 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 		return;
 	}
 	list_del(&tz->node);
-	if (tz->ops->unbind)
-		list_for_each_entry(cdev, &thermal_cdev_list, node)
-		    tz->ops->unbind(tz, cdev);
+
+	/* Unbind all cdevs associated with 'this' thermal zone */
+	list_for_each_entry(cdev, &thermal_cdev_list, node) {
+		if (tz->ops->unbind) {
+			tz->ops->unbind(tz, cdev);
+			continue;
+		}
+
+		if (!tzp || !tzp->tbp)
+			break;
+
+		for (i = 0; i < tzp->num_tbps; i++) {
+			if (tzp->tbp[i].cdev == cdev) {
+				__unbind(tz, tzp->tbp[i].trip_mask, cdev);
+				tzp->tbp[i].cdev = NULL;
+			}
+		}
+	}
+
 	mutex_unlock(&thermal_list_lock);
 
 	thermal_zone_device_set_polling(tz, 0);

@@ -1174,7 +1174,7 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
 }
 EXPORT_SYMBOL(thermal_cooling_device_unregister);
 
-static void thermal_cdev_do_update(struct thermal_cooling_device *cdev)
+void thermal_cdev_update(struct thermal_cooling_device *cdev)
 {
 	struct thermal_instance *instance;
 	unsigned long target = 0;

@@ -1195,13 +1195,14 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev)
 	cdev->ops->set_cur_state(cdev, target);
 	cdev->updated = true;
 }
+EXPORT_SYMBOL(thermal_cdev_update);
 
 static void thermal_zone_do_update(struct thermal_zone_device *tz)
 {
 	struct thermal_instance *instance;
 
 	list_for_each_entry(instance, &tz->thermal_instances, tz_node)
-		thermal_cdev_do_update(instance->cdev);
+		thermal_cdev_update(instance->cdev);
 }
 
 /*

@@ -225,6 +225,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *);
 int get_tz_trend(struct thermal_zone_device *, int);
 struct thermal_instance *get_thermal_instance(struct thermal_zone_device *,
 		struct thermal_cooling_device *, int);
+void thermal_cdev_update(struct thermal_cooling_device *);
+
 /*
  * The platform layer shall define a 'function' that provides the
  * parameters for all thermal zones in the platform. This pointer

@@ -27,3 +27,9 @@ config SPEAR_THERMAL
 	help
 	  Enable this to plug the SPEAr thermal sensor driver into the Linux
 	  thermal framework
+
+config FAIR_SHARE
+	bool "Fair-share thermal governor"
+	depends on THERMAL
+	help
+	  Enable this to manage platform thermals using fair-share governor.

@@ -3,4 +3,5 @@
 #
 
 obj-$(CONFIG_THERMAL)		+= thermal_sys.o
-obj-$(CONFIG_SPEAR_THERMAL)		+= spear_thermal.o

@@ -0,0 +1,113 @@
+/*
+ *  fair_share.c - A simple weight based Thermal governor
+ *
+ *  Copyright (C) 2012 Intel Corp
+ *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/thermal.h>
+
+#include "thermal_core.h"
+
+/**
+ * get_trip_level: - obtains the current trip level for a zone
+ * @tz:		thermal zone device
+ */
+static int get_trip_level(struct thermal_zone_device *tz)
+{
+	int count = 0;
+	unsigned long trip_temp;
+
+	if (tz->trips == 0 || !tz->ops->get_trip_temp)
+		return 0;
+
+	for (count = 0; count < tz->trips; count++) {
+		tz->ops->get_trip_temp(tz, count, &trip_temp);
+		if (tz->temperature < trip_temp)
+			break;
+	}
+	return count;
+}
+
+static long get_target_state(struct thermal_zone_device *tz,
+		struct thermal_cooling_device *cdev, int weight, int level)
+{
+	unsigned long max_state;
+
+	cdev->ops->get_max_state(cdev, &max_state);
+
+	return (long)(weight * level * max_state) / (100 * tz->trips);
+}
+
+/**
+ * fair_share_throttle - throttles devices asscciated with the given zone
+ * @tz - thermal_zone_device
+ *
+ * Throttling Logic: This uses three parameters to calculate the new
+ * throttle state of the cooling devices associated with the given zone.
+ *
+ * Parameters used for Throttling:
+ * P1. max_state: Maximum throttle state exposed by the cooling device.
+ * P2. weight[i]/100:
+ *	How 'effective' the 'i'th device is, in cooling the given zone.
+ * P3. cur_trip_level/max_no_of_trips:
+ *	This describes the extent to which the devices should be throttled.
+ *	We do not want to throttle too much when we trip a lower temperature,
+ *	whereas the throttling is at full swing if we trip critical levels.
+ *	(Heavily assumes the trip points are in ascending order)
+ * new_state of cooling device = P3 * P2 * P1
+ */
+void fair_share_throttle(struct thermal_zone_device *tz, int trip)
+{
+	struct thermal_zone_params *tzp;
+	struct thermal_cooling_device *cdev;
+	struct thermal_instance *instance;
+	int i;
+	int cur_trip_level = get_trip_level(tz);
+
+	if (!tz->tzp || !tz->tzp->tbp)
+		return;
+
+	tzp = tz->tzp;
+
+	for (i = 0; i < tzp->num_tbps; i++) {
+		if (!tzp->tbp[i].cdev)
+			continue;
+
+		cdev = tzp->tbp[i].cdev;
+		instance = get_thermal_instance(tz, cdev, trip);
+		if (!instance)
+			continue;
+
+		instance->target = get_target_state(tz, cdev,
+					tzp->tbp[i].weight, cur_trip_level);
+
+		instance->cdev->updated = false;
+		thermal_cdev_update(cdev);
+	}
+}
+EXPORT_SYMBOL(fair_share_throttle);
+
+MODULE_AUTHOR("Durgadoss R");
+MODULE_DESCRIPTION("A simple weight based thermal throttling governor");
+MODULE_LICENSE("GPL");

@@ -237,6 +237,15 @@ void thermal_cdev_update(struct thermal_cooling_device *);
  */
 extern int (*get_platform_thermal_params)(struct thermal_zone_device *);
 
+#ifdef CONFIG_FAIR_SHARE
+extern void fair_share_throttle(struct thermal_zone_device *tz, int trip);
+#else
+static inline void fair_share_throttle(struct thermal_zone_device *tz, int trip)
+{
+	return;
+}
+#endif
+
 #ifdef CONFIG_NET
 extern int thermal_generate_netlink_event(u32 orig, enum events event);
 #else

@@ -33,3 +33,9 @@ config FAIR_SHARE
 	depends on THERMAL
 	help
 	  Enable this to manage platform thermals using fair-share governor.
+
+config STEP_WISE
+	bool "Step_wise thermal governor"
+	depends on THERMAL
+	help
+	  Enable this to manage platform thermals using a simple linear

@@ -5,3 +5,4 @@
 obj-$(CONFIG_THERMAL)		+= thermal_sys.o
 obj-$(CONFIG_SPEAR_THERMAL)		+= spear_thermal.o
 obj-$(CONFIG_FAIR_SHARE)		+= fair_share.o
+obj-$(CONFIG_STEP_WISE)			+= step_wise.o

@@ -0,0 +1,173 @@
+/*
+ *  step_wise.c - A step-by-step Thermal throttling governor
+ *
+ *  Copyright (C) 2012 Intel Corp
+ *  Copyright (C) 2012 Durgadoss R <durgadoss.r@intel.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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/thermal.h>
+
+#include "thermal_core.h"
+
+/*
+ * If the temperature is higher than a trip point,
+ *    a. if the trend is THERMAL_TREND_RAISING, use higher cooling
+ *       state for this trip point
+ *    b. if the trend is THERMAL_TREND_DROPPING, use lower cooling
+ *       state for this trip point
+ */
+static unsigned long get_target_state(struct thermal_instance *instance,
+					enum thermal_trend trend)
+{
+	struct thermal_cooling_device *cdev = instance->cdev;
+	unsigned long cur_state;
+
+	cdev->ops->get_cur_state(cdev, &cur_state);
+
+	if (trend == THERMAL_TREND_RAISING) {
+		cur_state = cur_state < instance->upper ?
+			    (cur_state + 1) : instance->upper;
+	} else if (trend == THERMAL_TREND_DROPPING) {
+		cur_state = cur_state > instance->lower ?
+			    (cur_state - 1) : instance->lower;
+	}
+
+	return cur_state;
+}
+
+static void update_passive_instance(struct thermal_zone_device *tz,
+				enum thermal_trip_type type, int value)
+{
+	/*
+	 * If value is +1, activate a passive instance.
+	 * If value is -1, deactivate a passive instance.
+	 */
+	if (type == THERMAL_TRIP_PASSIVE || type == THERMAL_TRIPS_NONE)
+		tz->passive += value;
+}
+
+static void update_instance_for_throttle(struct thermal_zone_device *tz,
+				int trip, enum thermal_trip_type trip_type,
+				enum thermal_trend trend)
+{
+	struct thermal_instance *instance;
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		if (instance->trip != trip)
+			continue;
+
+		instance->target = get_target_state(instance, trend);
+
+		/* Activate a passive thermal instance */
+		if (instance->target == THERMAL_NO_TARGET)
+			update_passive_instance(tz, trip_type, 1);
+
+		instance->cdev->updated = false; /* cdev needs update */
+	}
+}
+
+static void update_instance_for_dethrottle(struct thermal_zone_device *tz,
+				int trip, enum thermal_trip_type trip_type)
+{
+	struct thermal_instance *instance;
+	struct thermal_cooling_device *cdev;
+	unsigned long cur_state;
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
+		if (instance->trip != trip ||
+			instance->target == THERMAL_NO_TARGET)
+			continue;
+
+		cdev = instance->cdev;
+		cdev->ops->get_cur_state(cdev, &cur_state);
+
+		instance->target = cur_state > instance->lower ?
+			    (cur_state - 1) : THERMAL_NO_TARGET;
+
+		/* Deactivate a passive thermal instance */
+		if (instance->target == THERMAL_NO_TARGET)
+			update_passive_instance(tz, trip_type, -1);
+
+		cdev->updated = false; /* cdev needs update */
+	}
+}
+
+static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
+{
+	long trip_temp;
+	enum thermal_trip_type trip_type;
+	enum thermal_trend trend;
+
+	if (trip == THERMAL_TRIPS_NONE) {
+		trip_temp = tz->forced_passive;
+		trip_type = THERMAL_TRIPS_NONE;
+	} else {
+		tz->ops->get_trip_temp(tz, trip, &trip_temp);
+		tz->ops->get_trip_type(tz, trip, &trip_type);
+	}
+
+	trend = get_tz_trend(tz, trip);
+
+	mutex_lock(&tz->lock);
+
+	if (tz->temperature >= trip_temp)
+		update_instance_for_throttle(tz, trip, trip_type, trend);
+	else
+		update_instance_for_dethrottle(tz, trip, trip_type);
+
+	mutex_unlock(&tz->lock);
+}
+
+/**
+ * step_wise_throttle - throttles devices asscciated with the given zone
+ * @tz - thermal_zone_device
+ * @trip - the trip point
+ * @trip_type - type of the trip point
+ *
+ * Throttling Logic: This uses the trend of the thermal zone to throttle.
+ * If the thermal zone is 'heating up' this throttles all the cooling
+ * devices associated with the zone and its particular trip point, by one
+ * step. If the zone is 'cooling down' it brings back the performance of
+ * the devices by one step.
+ */
+void step_wise_throttle(struct thermal_zone_device *tz, int trip)
+{
+	struct thermal_instance *instance;
+
+	thermal_zone_trip_update(tz, trip);
+
+	if (tz->forced_passive)
+		thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE);
+
+	mutex_lock(&tz->lock);
+
+	list_for_each_entry(instance, &tz->thermal_instances, tz_node)
+		thermal_cdev_update(instance->cdev);
+
+	mutex_unlock(&tz->lock);
+}
+EXPORT_SYMBOL(step_wise_throttle);
+
+MODULE_AUTHOR("Durgadoss R");
+MODULE_DESCRIPTION("A step-by-step thermal throttling governor");
+MODULE_LICENSE("GPL");