--- /dev/null
+Generic Thermal Sysfs driver How To
+=========================
+
+Written by Sujith Thomas <sujith.thomas@intel.com>, Zhang Rui <rui.zhang@intel.com>
+
+Updated: 2 January 2008
+
+Copyright (c) 2008 Intel Corporation
+
+
+0. Introduction
+
+The generic thermal sysfs provides a set of interfaces for thermal zone devices (sensors)
+and thermal cooling devices (fan, processor...) to register with the thermal management
+solution and to be a part of it.
+
+This how-to focusses on enabling new thermal zone and cooling devices to participate
+in thermal management.
+This solution is platform independent and any type of thermal zone devices and
+cooling devices should be able to make use of the infrastructure.
+
+The main task of the thermal sysfs driver is to expose thermal zone attributes as well
+as cooling device attributes to the user space.
+An intelligent thermal management application can make decisions based on inputs
+from thermal zone attributes (the current temperature and trip point temperature)
+and throttle appropriate devices.
+
+[0-*] denotes any positive number starting from 0
+[1-*] denotes any positive number starting from 1
+
+1. thermal sysfs driver interface functions
+
+1.1 thermal zone device interface
+1.1.1 struct thermal_zone_device *thermal_zone_device_register(char *name, int trips,
+ void *devdata, struct thermal_zone_device_ops *ops)
+
+ This interface function adds a new thermal zone device (sensor) to
+ /sys/class/thermal folder as thermal_zone[0-*].
+ It tries to bind all the thermal cooling devices registered at the same time.
+
+ name: the thermal zone name.
+ trips: the total number of trip points this thermal zone supports.
+ devdata: device private data
+ ops: thermal zone device callbacks.
+ .bind: bind the thermal zone device with a thermal cooling device.
+ .unbind: unbing the thermal zone device with a thermal cooling device.
+ .get_temp: get the current temperature of the thermal zone.
+ .get_mode: get the current mode (user/kernel) of the thermal zone.
+ "kernel" means thermal management is done in kernel.
+ "user" will prevent kernel thermal driver actions upon trip points
+ so that user applications can take charge of thermal management.
+ .set_mode: set the mode (user/kernel) of the thermal zone.
+ .get_trip_type: get the type of certain trip point.
+ .get_trip_temp: get the temperature above which the certain trip point
+ will be fired.
+
+1.1.2 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
+
+ This interface function removes the thermal zone device.
+ It deletes the corresponding entry form /sys/class/thermal folder and unbind all
+ the thermal cooling devices it uses.
+
+1.2 thermal cooling device interface
+1.2.1 struct thermal_cooling_device *thermal_cooling_device_register(char *name,
+ void *devdata, struct thermal_cooling_device_ops *)
+
+ 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 register at the same time.
+ name: the cooling device name.
+ devdata: device private data.
+ ops: thermal cooling devices callbacks.
+ .get_max_state: get the Maximum throttle state of the cooling device.
+ .get_cur_state: get the Current throttle state of the cooling device.
+ .set_cur_state: set the Current throttle state of the cooling device.
+
+1.2.2 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
+
+ This interface function remove the thermal cooling device.
+ It deletes the corresponding entry form /sys/class/thermal folder and unbind
+ itself from all the thermal zone devices using it.
+
+1.3 interface for binding a thermal zone device with a thermal cooling device
+1.3.1 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
+ int trip, struct thermal_cooling_device *cdev);
+
+ This interface function bind a thermal cooling device to the certain trip point
+ of a thermal zone device.
+ This function is usually called in the thermal zone device .bind callback.
+ tz: the thermal zone device
+ cdev: thermal cooling device
+ trip: indicates which trip point the cooling devices is associated with
+ in this thermal zone.
+
+1.3.2 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
+ int trip, struct thermal_cooling_device *cdev);
+
+ This interface function unbind a thermal cooling device from the certain trip point
+ of a thermal zone device.
+ This function is usually called in the thermal zone device .unbind callback.
+ tz: the thermal zone device
+ cdev: thermal cooling device
+ trip: indicates which trip point the cooling devices is associated with
+ in this thermal zone.
+
+2. sysfs attributes structure
+
+RO read only value
+RW read/write value
+
+All thermal sysfs attributes will be represented under /sys/class/thermal
+/sys/class/thermal/
+
+Thermal zone device sys I/F, created once it's registered:
+|thermal_zone[0-*]:
+ |-----type: Type of the thermal zone
+ |-----temp: Current temperature
+ |-----mode: Working mode of the thermal zone
+ |-----trip_point_[0-*]_temp: Trip point temperature
+ |-----trip_point_[0-*]_type: Trip point type
+
+Thermal cooling device sys I/F, created once it's registered:
+|cooling_device[0-*]:
+ |-----type : Type of the cooling device(processor/fan/...)
+ |-----max_state: Maximum cooling state of the cooling device
+ |-----cur_state: Current cooling state of the cooling device
+
+
+These two dynamic attributes are created/removed in pairs.
+They represent the relationship between a thermal zone and its associated cooling device.
+They are created/removed for each
+thermal_zone_bind_cooling_device/thermal_zone_unbind_cooling_device successful exection.
+
+|thermal_zone[0-*]
+ |-----cdev[0-*]: The [0-*]th cooling device in the current thermal zone
+ |-----cdev[0-*]_trip_point: Trip point that cdev[0-*] is associated with
+
+
+***************************
+* Thermal zone attributes *
+***************************
+
+type Strings which represent the thermal zone type.
+ This is given by thermal zone driver as part of registration.
+ Eg: "ACPI thermal zone" indicates it's a ACPI thermal device
+ RO
+ Optional
+
+temp Current temperature as reported by thermal zone (sensor)
+ Unit: degree celsius
+ RO
+ Required
+
+mode One of the predifned values in [kernel, user]
+ This file gives information about the algorithm
+ that is currently managing the thermal zone.
+ It can be either default kernel based algorithm
+ or user space application.
+ RW
+ Optional
+ kernel = Thermal management in kernel thermal zone driver.
+ user = Preventing kernel thermal zone driver actions upon
+ trip points so that user application can take full
+ charge of the thermal management.
+
+trip_point_[0-*]_temp The temperature above which trip point will be fired
+ Unit: degree celsius
+ RO
+ Optional
+
+trip_point_[0-*]_type Strings which indicate the type of the trip point
+ Eg. it can be one of critical, hot, passive,
+ active[0-*] for ACPI thermal zone.
+ RO
+ Optional
+
+cdev[0-*] Sysfs link to the thermal cooling device node where the sys I/F
+ for cooling device throttling control represents.
+ RO
+ Optional
+
+cdev[0-*]_trip_point The trip point with which cdev[0-*] is assocated in this thermal zone
+ -1 means the cooling device is not associated with any trip point.
+ RO
+ Optional
+
+******************************
+* Cooling device attributes *
+******************************
+
+type String which represents the type of device
+ eg: For generic ACPI: this should be "Fan",
+ "Processor" or "LCD"
+ eg. For memory controller device on intel_menlow platform:
+ this should be "Memory controller"
+ RO
+ Optional
+
+max_state The maximum permissible cooling state of this cooling device.
+ RO
+ Required
+
+cur_state The current cooling state of this cooling device.
+ the value can any integer numbers between 0 and max_state,
+ cur_state == 0 means no cooling
+ cur_state == max_state means the maximum cooling.
+ RW
+ Required
+
+3. A simple implementation
+
+ACPI thermal zone may support multiple trip points like critical/hot/passive/active.
+If an ACPI thermal zone supports critical, passive, active[0] and active[1] at the same time,
+it may register itself as a thermale_zone_device (thermal_zone1) with 4 trip points in all.
+It has one processor and one fan, which are both registered as thermal_cooling_device.
+If the processor is listed in _PSL method, and the fan is listed in _AL0 method,
+the sys I/F structure will be built like this:
+
+/sys/class/thermal:
+
+|thermal_zone1:
+ |-----type: ACPI thermal zone
+ |-----temp: 37
+ |-----mode: kernel
+ |-----trip_point_0_temp: 100
+ |-----trip_point_0_type: critical
+ |-----trip_point_1_temp: 80
+ |-----trip_point_1_type: passive
+ |-----trip_point_2_temp: 70
+ |-----trip_point_2_type: active[0]
+ |-----trip_point_3_temp: 60
+ |-----trip_point_3_type: active[1]
+ |-----cdev0: --->/sys/class/thermal/cooling_device0
+ |-----cdev0_trip_point: 1 /* cdev0 can be used for passive */
+ |-----cdev1: --->/sys/class/thermal/cooling_device3
+ |-----cdev1_trip_point: 2 /* cdev1 can be used for active[0]*/
+
+|cooling_device0:
+ |-----type: Processor
+ |-----max_state: 8
+ |-----cur_state: 0
+
+|cooling_device3:
+ |-----type: Fan
+ |-----max_state: 2
+ |-----cur_state: 0
--- /dev/null
+/*
+ * thermal.c - Generic Thermal Management Sysfs support.
+ *
+ * Copyright (C) 2008 Intel Corp
+ * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
+ * Copyright (C) 2008 Sujith Thomas <sujith.thomas@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.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kdev_t.h>
+#include <linux/idr.h>
+#include <linux/thermal.h>
+#include <linux/spinlock.h>
+
+MODULE_AUTHOR("Zhang Rui")
+MODULE_DESCRIPTION("Generic thermal management sysfs support");
+MODULE_LICENSE("GPL");
+
+#define PREFIX "Thermal: "
+
+struct thermal_cooling_device_instance {
+ int id;
+ char name[THERMAL_NAME_LENGTH];
+ struct thermal_zone_device *tz;
+ struct thermal_cooling_device *cdev;
+ int trip;
+ char attr_name[THERMAL_NAME_LENGTH];
+ struct device_attribute attr;
+ struct list_head node;
+};
+
+static DEFINE_IDR(thermal_tz_idr);
+static DEFINE_IDR(thermal_cdev_idr);
+static DEFINE_MUTEX(thermal_idr_lock);
+
+static LIST_HEAD(thermal_tz_list);
+static LIST_HEAD(thermal_cdev_list);
+static DEFINE_MUTEX(thermal_list_lock);
+
+static int get_idr(struct idr *idr, struct mutex *lock, int *id)
+{
+ int err;
+
+ again:
+ if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0))
+ return -ENOMEM;
+
+ if (lock)
+ mutex_lock(lock);
+ err = idr_get_new(idr, NULL, id);
+ if (lock)
+ mutex_unlock(lock);
+ if (unlikely(err == -EAGAIN))
+ goto again;
+ else if (unlikely(err))
+ return err;
+
+ *id = *id & MAX_ID_MASK;
+ return 0;
+}
+
+static void release_idr(struct idr *idr, struct mutex *lock, int id)
+{
+ if (lock)
+ mutex_lock(lock);
+ idr_remove(idr, id);
+ if (lock)
+ mutex_unlock(lock);
+}
+
+/* sys I/F for thermal zone */
+
+#define to_thermal_zone(_dev) \
+ container_of(_dev, struct thermal_zone_device, device)
+
+static ssize_t
+type_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+
+ return sprintf(buf, "%s\n", tz->type);
+}
+
+static ssize_t
+temp_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+
+ if (!tz->ops->get_temp)
+ return -EPERM;
+
+ return tz->ops->get_temp(tz, buf);
+}
+
+static ssize_t
+mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+
+ if (!tz->ops->get_mode)
+ return -EPERM;
+
+ return tz->ops->get_mode(tz, buf);
+}
+
+static ssize_t
+mode_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+ int result;
+
+ if (!tz->ops->set_mode)
+ return -EPERM;
+
+ result = tz->ops->set_mode(tz, buf);
+ if (result)
+ return result;
+
+ return count;
+}
+
+static ssize_t
+trip_point_type_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+ int trip;
+
+ if (!tz->ops->get_trip_type)
+ return -EPERM;
+
+ if (!sscanf(attr->attr.name, "trip_point_%d_type", &trip))
+ return -EINVAL;
+
+ return tz->ops->get_trip_type(tz, trip, buf);
+}
+
+static ssize_t
+trip_point_temp_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct thermal_zone_device *tz = to_thermal_zone(dev);
+ int trip;
+
+ if (!tz->ops->get_trip_temp)
+ return -EPERM;
+
+ if (!sscanf(attr->attr.name, "trip_point_%d_temp", &trip))
+ return -EINVAL;
+
+ return tz->ops->get_trip_temp(tz, trip, buf);
+}
+
+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 struct device_attribute trip_point_attrs[] = {
+ __ATTR(trip_point_0_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_0_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_1_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_1_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_2_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_2_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_3_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_3_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_4_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_4_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_5_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_5_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_6_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_6_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_7_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_7_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_8_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_8_temp, 0444, trip_point_temp_show, NULL),
+ __ATTR(trip_point_9_type, 0444, trip_point_type_show, NULL),
+ __ATTR(trip_point_9_temp, 0444, trip_point_temp_show, NULL),
+};
+
+#define TRIP_POINT_ATTR_ADD(_dev, _index, result) \
+do { \
+ result = device_create_file(_dev, \
+ &trip_point_attrs[_index * 2]); \
+ if (result) \
+ break; \
+ result = device_create_file(_dev, \
+ &trip_point_attrs[_index * 2 + 1]); \
+} while (0)
+
+#define TRIP_POINT_ATTR_REMOVE(_dev, _index) \
+do { \
+ device_remove_file(_dev, &trip_point_attrs[_index * 2]); \
+ device_remove_file(_dev, &trip_point_attrs[_index * 2 + 1]); \
+} while (0)
+
+/* sys I/F for cooling device */
+#define to_cooling_device(_dev) \
+ container_of(_dev, struct thermal_cooling_device, device)
+
+static ssize_t
+thermal_cooling_device_type_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+
+ return sprintf(buf, "%s\n", cdev->type);
+}
+
+static ssize_t
+thermal_cooling_device_max_state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+
+ return cdev->ops->get_max_state(cdev, buf);
+}
+
+static ssize_t
+thermal_cooling_device_cur_state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+
+ return cdev->ops->get_cur_state(cdev, buf);
+}
+
+static ssize_t
+thermal_cooling_device_cur_state_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ int state;
+ int result;
+
+ if (!sscanf(buf, "%d\n", &state))
+ return -EINVAL;
+
+ if (state < 0)
+ return -EINVAL;
+
+ result = cdev->ops->set_cur_state(cdev, state);
+ if (result)
+ return result;
+ return count;
+}
+
+static struct device_attribute dev_attr_cdev_type =
+ __ATTR(type, 0444, thermal_cooling_device_type_show, NULL);
+static DEVICE_ATTR(max_state, 0444,
+ thermal_cooling_device_max_state_show, NULL);
+static DEVICE_ATTR(cur_state, 0644,
+ thermal_cooling_device_cur_state_show,
+ thermal_cooling_device_cur_state_store);
+
+static ssize_t
+thermal_cooling_device_trip_point_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device_instance *instance;
+
+ instance =
+ container_of(attr, struct thermal_cooling_device_instance, attr);
+
+ if (instance->trip == THERMAL_TRIPS_NONE)
+ return sprintf(buf, "-1\n");
+ else
+ return sprintf(buf, "%d\n", instance->trip);
+}
+
+/* Device management */
+
+/**
+ * thermal_zone_bind_cooling_device - bind a cooling device to a thermal zone
+ * this function is usually called in the thermal zone device .bind callback.
+ * @tz: thermal zone device
+ * @trip: indicates which trip point the cooling devices is
+ * associated with in this thermal zone.
+ * @cdev: thermal cooling device
+ */
+int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
+ int trip,
+ struct thermal_cooling_device *cdev)
+{
+ struct thermal_cooling_device_instance *dev;
+ struct thermal_cooling_device_instance *pos;
+ int result;
+
+ if (trip >= tz->trips ||
+ (trip < 0 && trip != THERMAL_TRIPS_NONE))
+ return -EINVAL;
+
+ if (!tz || !cdev)
+ return -EINVAL;
+
+ dev =
+ kzalloc(sizeof(struct thermal_cooling_device_instance), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+ dev->tz = tz;
+ dev->cdev = cdev;
+ dev->trip = trip;
+ result = get_idr(&tz->idr, &tz->lock, &dev->id);
+ if (result)
+ goto free_mem;
+
+ sprintf(dev->name, "cdev%d", dev->id);
+ result =
+ sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
+ if (result)
+ goto release_idr;
+
+ sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
+ dev->attr.attr.name = dev->attr_name;
+ dev->attr.attr.mode = 0444;
+ dev->attr.show = thermal_cooling_device_trip_point_show;
+ result = device_create_file(&tz->device, &dev->attr);
+ if (result)
+ goto remove_symbol_link;
+
+ mutex_lock(&tz->lock);
+ list_for_each_entry(pos, &tz->cooling_devices, node)
+ if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
+ result = -EEXIST;
+ break;
+ }
+ if (!result)
+ list_add_tail(&dev->node, &tz->cooling_devices);
+ mutex_unlock(&tz->lock);
+
+ if (!result)
+ return 0;
+
+ device_remove_file(&tz->device, &dev->attr);
+ remove_symbol_link:
+ sysfs_remove_link(&tz->device.kobj, dev->name);
+ release_idr:
+ release_idr(&tz->idr, &tz->lock, dev->id);
+ free_mem:
+ kfree(dev);
+ return result;
+}
+EXPORT_SYMBOL(thermal_zone_bind_cooling_device);
+
+/**
+ * thermal_zone_unbind_cooling_device - unbind a cooling device from a thermal zone
+ * this function is usually called in the thermal zone device .unbind callback.
+ * @tz: thermal zone device
+ * @trip: indicates which trip point the cooling devices is
+ * associated with in this thermal zone.
+ * @cdev: thermal cooling device
+ */
+int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
+ int trip,
+ struct thermal_cooling_device *cdev)
+{
+ struct thermal_cooling_device_instance *pos, *next;
+
+ mutex_lock(&tz->lock);
+ list_for_each_entry_safe(pos, next, &tz->cooling_devices, node) {
+ if (pos->tz == tz && pos->trip == trip
+ && pos->cdev == cdev) {
+ list_del(&pos->node);
+ mutex_unlock(&tz->lock);
+ goto unbind;
+ }
+ }
+ mutex_unlock(&tz->lock);
+
+ return -ENODEV;
+
+ unbind:
+ device_remove_file(&tz->device, &pos->attr);
+ sysfs_remove_link(&tz->device.kobj, pos->name);
+ release_idr(&tz->idr, &tz->lock, pos->id);
+ kfree(pos);
+ return 0;
+}
+EXPORT_SYMBOL(thermal_zone_unbind_cooling_device);
+
+static void thermal_release(struct device *dev)
+{
+ struct thermal_zone_device *tz;
+ struct thermal_cooling_device *cdev;
+
+ if (!strncmp(dev->bus_id, "thermal_zone", sizeof "thermal_zone" - 1)) {
+ tz = to_thermal_zone(dev);
+ kfree(tz);
+ } else {
+ cdev = to_cooling_device(dev);
+ kfree(cdev);
+ }
+}
+
+static struct class thermal_class = {
+ .name = "thermal",
+ .dev_release = thermal_release,
+};
+
+/**
+ * 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.
+ */
+struct thermal_cooling_device *thermal_cooling_device_register(char *type,
+ void *devdata, struct thermal_cooling_device_ops *ops)
+{
+ struct thermal_cooling_device *cdev;
+ struct thermal_zone_device *pos;
+ int result;
+
+ if (strlen(type) >= THERMAL_NAME_LENGTH)
+ return NULL;
+
+ if (!ops || !ops->get_max_state || !ops->get_cur_state ||
+ !ops->set_cur_state)
+ return NULL;
+
+ cdev = kzalloc(sizeof(struct thermal_cooling_device), GFP_KERNEL);
+ if (!cdev)
+ return NULL;
+
+ result = get_idr(&thermal_cdev_idr, &thermal_idr_lock, &cdev->id);
+ if (result) {
+ kfree(cdev);
+ return NULL;
+ }
+
+ strcpy(cdev->type, type);
+ cdev->ops = ops;
+ cdev->device.class = &thermal_class;
+ cdev->devdata = devdata;
+ sprintf(cdev->device.bus_id, "cooling_device%d", cdev->id);
+ result = device_register(&cdev->device);
+ if (result) {
+ release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
+ kfree(cdev);
+ return NULL;
+ }
+
+ /* sys I/F */
+ if (type) {
+ result = device_create_file(&cdev->device,
+ &dev_attr_cdev_type);
+ if (result)
+ goto unregister;
+ }
+
+ result = device_create_file(&cdev->device, &dev_attr_max_state);
+ if (result)
+ goto unregister;
+
+ result = device_create_file(&cdev->device, &dev_attr_cur_state);
+ if (result)
+ goto unregister;
+
+ 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;
+
+ unregister:
+ release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
+ device_unregister(&cdev->device);
+ return NULL;
+}
+EXPORT_SYMBOL(thermal_cooling_device_register);
+
+/**
+ * thermal_cooling_device_unregister - removes the registered thermal cooling device
+ *
+ * @cdev: the thermal cooling device to remove.
+ *
+ * thermal_cooling_device_unregister() must be called when the device is no
+ * longer needed.
+ */
+void thermal_cooling_device_unregister(struct
+ thermal_cooling_device
+ *cdev)
+{
+ struct thermal_zone_device *tz;
+ struct thermal_cooling_device *pos = NULL;
+
+ if (!cdev)
+ return;
+
+ mutex_lock(&thermal_list_lock);
+ list_for_each_entry(pos, &thermal_cdev_list, node)
+ if (pos == cdev)
+ break;
+ if (pos != cdev) {
+ /* thermal cooling device not found */
+ mutex_unlock(&thermal_list_lock);
+ return;
+ }
+ list_del(&cdev->node);
+ list_for_each_entry(tz, &thermal_tz_list, node) {
+ if (!tz->ops->unbind)
+ continue;
+ tz->ops->unbind(tz, cdev);
+ }
+ 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);
+ device_remove_file(&cdev->device, &dev_attr_cur_state);
+
+ release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
+ device_unregister(&cdev->device);
+ return;
+}
+EXPORT_SYMBOL(thermal_cooling_device_unregister);
+
+/**
+ * thermal_zone_device_register - register a new thermal zone device
+ * @type: the thermal zone device type
+ * @trips: the number of trip points the thermal zone support
+ * @devdata: private device data
+ * @ops: standard thermal zone device callbacks
+ *
+ * thermal_zone_device_unregister() must be called when the device is no
+ * longer needed.
+ */
+struct thermal_zone_device *thermal_zone_device_register(char *type,
+ int trips, void *devdata,
+ struct thermal_zone_device_ops *ops)
+{
+ struct thermal_zone_device *tz;
+ struct thermal_cooling_device *pos;
+ int result;
+ int count;
+
+ if (strlen(type) >= THERMAL_NAME_LENGTH)
+ return NULL;
+
+ if (trips > THERMAL_MAX_TRIPS || trips < 0)
+ return NULL;
+
+ if (!ops || !ops->get_temp)
+ return NULL;
+
+ tz = kzalloc(sizeof(struct thermal_zone_device), GFP_KERNEL);
+ if (!tz)
+ return NULL;
+
+ INIT_LIST_HEAD(&tz->cooling_devices);
+ idr_init(&tz->idr);
+ mutex_init(&tz->lock);
+ result = get_idr(&thermal_tz_idr, &thermal_idr_lock, &tz->id);
+ if (result) {
+ kfree(tz);
+ return NULL;
+ }
+
+ strcpy(tz->type, type);
+ tz->ops = ops;
+ tz->device.class = &thermal_class;
+ tz->devdata = devdata;
+ tz->trips = trips;
+ sprintf(tz->device.bus_id, "thermal_zone%d", tz->id);
+ result = device_register(&tz->device);
+ if (result) {
+ release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
+ kfree(tz);
+ return NULL;
+ }
+
+ /* sys I/F */
+ if (type) {
+ result = device_create_file(&tz->device, &dev_attr_type);
+ if (result)
+ goto unregister;
+ }
+
+ result = device_create_file(&tz->device, &dev_attr_temp);
+ if (result)
+ goto unregister;
+
+ if (ops->get_mode) {
+ result = device_create_file(&tz->device, &dev_attr_mode);
+ if (result)
+ goto unregister;
+ }
+
+ for (count = 0; count < trips; count++) {
+ TRIP_POINT_ATTR_ADD(&tz->device, count, result);
+ if (result)
+ goto unregister;
+ }
+
+ 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);
+
+ if (!result)
+ return tz;
+
+ unregister:
+ release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
+ device_unregister(&tz->device);
+ return NULL;
+}
+EXPORT_SYMBOL(thermal_zone_device_register);
+
+/**
+ * thermal_device_unregister - removes the registered thermal zone device
+ *
+ * @tz: the thermal zone device to remove
+ */
+void thermal_zone_device_unregister(struct thermal_zone_device *tz)
+{
+ struct thermal_cooling_device *cdev;
+ struct thermal_zone_device *pos = NULL;
+ int count;
+
+ if (!tz)
+ return;
+
+ mutex_lock(&thermal_list_lock);
+ list_for_each_entry(pos, &thermal_tz_list, node)
+ if (pos == tz)
+ break;
+ if (pos != tz) {
+ /* thermal zone device not found */
+ mutex_unlock(&thermal_list_lock);
+ return;
+ }
+ list_del(&tz->node);
+ if (tz->ops->unbind)
+ list_for_each_entry(cdev, &thermal_cdev_list, node)
+ tz->ops->unbind(tz, cdev);
+ mutex_unlock(&thermal_list_lock);
+
+ if (tz->type[0])
+ device_remove_file(&tz->device, &dev_attr_type);
+ device_remove_file(&tz->device, &dev_attr_temp);
+ if (tz->ops->get_mode)
+ device_remove_file(&tz->device, &dev_attr_mode);
+
+ for (count = 0; count < tz->trips; count++)
+ TRIP_POINT_ATTR_REMOVE(&tz->device, count);
+
+ release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
+ idr_destroy(&tz->idr);
+ mutex_destroy(&tz->lock);
+ device_unregister(&tz->device);
+ return;
+}
+EXPORT_SYMBOL(thermal_zone_device_unregister);
+
+static int __init thermal_init(void)
+{
+ int result = 0;
+
+ result = class_register(&thermal_class);
+ if (result) {
+ idr_destroy(&thermal_tz_idr);
+ idr_destroy(&thermal_cdev_idr);
+ mutex_destroy(&thermal_idr_lock);
+ mutex_destroy(&thermal_list_lock);
+ }
+ return result;
+}
+
+static void __exit thermal_exit(void)
+{
+ class_unregister(&thermal_class);
+ idr_destroy(&thermal_tz_idr);
+ idr_destroy(&thermal_cdev_idr);
+ mutex_destroy(&thermal_idr_lock);
+ mutex_destroy(&thermal_list_lock);
+}
+
+subsys_initcall(thermal_init);
+module_exit(thermal_exit);
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff