path: root/drivers/thermal/thermal.c

/*
 *  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,