of-thermal.c - Android社区 - https://www.androidos.net.cn/

Kernel | 4.4

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/*
 *  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 <linux/thermal.h>

#include "thermal_core.h"

/***   Private data structures to represent thermal device tree data ***/

/**
 * 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
 * @slope: slope of the temperature adjustment curve
 * @offset: offset of the temperature adjustment curve
 * @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
 * @ops: set of callbacks to handle the thermal zone based on DT
 */

struct __thermal_zone {
	enum thermal_device_mode mode;
	int passive_delay;
	int polling_delay;
	int slope;
	int offset;

/* trip data */
	int ntrips;
	struct thermal_trip *trips;

/* cooling binding data */
	int num_tbps;
	struct __thermal_bind_params *tbps;

/* sensor interface */
	void *sensor_data;
	const struct thermal_zone_of_device_ops *ops;
};

/***   DT thermal zone device callbacks   ***/

static int of_thermal_get_temp(struct thermal_zone_device *tz,
			       int *temp)
{
	struct __thermal_zone *data = tz->devdata;

if (!data->ops->get_temp)
		return -EINVAL;

return data->ops->get_temp(data->sensor_data, temp);
}

/**
 * of_thermal_get_ntrips - function to export number of available trip
 *			   points.
 * @tz: pointer to a thermal zone
 *
 * This function is a globally visible wrapper to get number of trip points
 * stored in the local struct __thermal_zone
 *
 * Return: number of available trip points, -ENODEV when data not available
 */
int of_thermal_get_ntrips(struct thermal_zone_device *tz)
{
	struct __thermal_zone *data = tz->devdata;

if (!data || IS_ERR(data))
		return -ENODEV;

return data->ntrips;
}
EXPORT_SYMBOL_GPL(of_thermal_get_ntrips);

/**
 * of_thermal_is_trip_valid - function to check if trip point is valid
 *
 * @tz:	pointer to a thermal zone
 * @trip:	trip point to evaluate
 *
 * This function is responsible for checking if passed trip point is valid
 *
 * Return: true if trip point is valid, false otherwise
 */
bool of_thermal_is_trip_valid(struct thermal_zone_device *tz, int trip)
{
	struct __thermal_zone *data = tz->devdata;

if (!data || trip >= data->ntrips || trip < 0)
		return false;

return true;
}
EXPORT_SYMBOL_GPL(of_thermal_is_trip_valid);

/**
 * of_thermal_get_trip_points - function to get access to a globally exported
 *				trip points
 *
 * @tz:	pointer to a thermal zone
 *
 * This function provides a pointer to trip points table
 *
 * Return: pointer to trip points table, NULL otherwise
 */
const struct thermal_trip *
of_thermal_get_trip_points(struct thermal_zone_device *tz)
{
	struct __thermal_zone *data = tz->devdata;

if (!data)
		return NULL;

return data->trips;
}
EXPORT_SYMBOL_GPL(of_thermal_get_trip_points);

/**
 * of_thermal_set_emul_temp - function to set emulated temperature
 *
 * @tz:	pointer to a thermal zone
 * @temp:	temperature to set
 *
 * This function gives the ability to set emulated value of temperature,
 * which is handy for debugging
 *
 * Return: zero on success, error code otherwise
 */
static int of_thermal_set_emul_temp(struct thermal_zone_device *tz,
				    int temp)
{
	struct __thermal_zone *data = tz->devdata;

if (!data->ops || !data->ops->set_emul_temp)
		return -EINVAL;

return data->ops->set_emul_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->ops->get_trend)
		return -EINVAL;

r = data->ops->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->max,
						tbp->min,
						tbp->usage);
			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;