path: root/drivers/thermal/thermal_sysfs.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  thermal.c - sysfs interface of thermal devices
 *
 *  Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
 *
 *  Highly based on original thermal_core.c
 *  Copyright (C) 2008 Intel Corp
 *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
 *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/container_of.h>
#include <linux/sysfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/jiffies.h>

#include "thermal_core.h"

/* sys I/F for thermal zone */

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);
	int temperature, ret;

	ret = thermal_zone_get_temp(tz, &temperature);

	if (!ret)
		return sprintf(buf, "%d\n", temperature);

	if (ret == -EAGAIN)
		return -ENODATA;

	return ret;
}

static ssize_t
mode_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct thermal_zone_device *tz = to_thermal_zone(dev);

	guard(thermal_zone)(tz);

	if (tz->mode == THERMAL_DEVICE_ENABLED)
		return sprintf(buf, "enabled\n");

	return sprintf(buf, "disabled\n");
}

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 (!strncmp(buf, "enabled", sizeof("enabled") - 1))
		result = thermal_zone_device_enable(tz);
	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
		result = thermal_zone_device_disable(tz);
	else
		result = -EINVAL;

	if (result)
		return result;

	return count;
}

#define thermal_trip_of_attr(_ptr_, _attr_)				\
	({ 								\
		struct thermal_trip_desc *td;				\
									\
		td = container_of(_ptr_, struct thermal_trip_desc,	\
				  trip_attrs._attr_.attr);		\
		&td->trip;						\
	})

static ssize_t
trip_point_type_show(struct device *dev, struct device_attribute *attr,
		     char *buf)
{
	struct thermal_trip *trip = thermal_trip_of_attr(attr, type);

	return sprintf(buf, "%s\n", thermal_trip_type_name(trip->type));
}

static ssize_t
trip_point_temp_store(struct device *dev, struct device_attribute *attr,
		      const char *buf, size_t count)
{
	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);
	struct thermal_zone_device *tz = to_thermal_zone(dev);
	int temp;

	if (kstrtoint(buf, 10, &temp))
		return -EINVAL;

	guard(thermal_zone)(tz);

	if (temp == trip->temperature)
		return count;

	/* Arrange the condition to avoid integer overflows. */
	if (temp != THERMAL_TEMP_INVALID &&
	    temp <= trip->hysteresis + THERMAL_TEMP_INVALID)
		return -EINVAL;

	if (tz->ops.set_trip_temp) {
		int ret;

		ret = tz->ops.set_trip_temp(tz, trip, temp);
		if (ret)
			return ret;
	}

	thermal_zone_set_trip_temp(tz, trip, temp);

	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);

	return count;
}

static ssize_t
trip_point_temp_show(struct device *dev, struct device_attribute *attr,
		     char *buf)
{
	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);

	return sprintf(buf, "%d\n", READ_ONCE(trip->temperature));
}

static ssize_t
trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
		      const char *buf, size_t count)
{
	struct thermal_trip *trip = thermal_trip_of_attr(attr, hyst);
	struct thermal_zone_device *tz = to_thermal_zone(dev);
	int hyst;

	if (kstrtoint(buf, 10, &hyst) || hyst < 0)
		return -EINVAL;

	guard(thermal_zone)(tz);

	if (hyst == trip->hysteresis)
		return count;

	/*
	 * Allow the hysteresis to be updated when the temperature is invalid
	 * to allow user space to avoid having to adjust hysteresis after a
	 * valid temperature has been set, but in that case just change the
	 * value and do nothing else.
	 */
	if (trip->temperature == THERMAL_TEMP_INVALID) {
		WRITE_ONCE(trip->hysteresis, hyst);
		return count