path: root/drivers/acpi/thermal.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 *  This driver fully implements the ACPI thermal policy as described in the
 *  ACPI 2.0 Specification.
 *
 *  TBD: 1. Implement passive cooling hysteresis.
 *       2. Enhance passive cooling (CPU) states/limit interface to support
 *          concepts of 'multiple limiters', upper/lower limits, etc.
 */

#define pr_fmt(fmt) "ACPI: thermal: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/jiffies.h>
#include <linux/kmod.h>
#include <linux/reboot.h>
#include <linux/device.h>
#include <linux/thermal.h>
#include <linux/acpi.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
#include <linux/units.h>

#include "internal.h"

#define ACPI_THERMAL_CLASS		"thermal_zone"
#define ACPI_THERMAL_DEVICE_NAME	"Thermal Zone"
#define ACPI_THERMAL_NOTIFY_TEMPERATURE	0x80
#define ACPI_THERMAL_NOTIFY_THRESHOLDS	0x81
#define ACPI_THERMAL_NOTIFY_DEVICES	0x82
#define ACPI_THERMAL_NOTIFY_CRITICAL	0xF0
#define ACPI_THERMAL_NOTIFY_HOT		0xF1
#define ACPI_THERMAL_MODE_ACTIVE	0x00

#define ACPI_THERMAL_MAX_ACTIVE		10
#define ACPI_THERMAL_MAX_LIMIT_STR_LEN	65

#define ACPI_THERMAL_TRIP_PASSIVE	(-1)

/*
 * This exception is thrown out in two cases:
 * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 *   when re-evaluating the AML code.
 * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 */
#define ACPI_THERMAL_TRIPS_EXCEPTION(tz, str) \
do { \
	acpi_handle_info(tz->device->handle, \
			 "ACPI thermal trip point %s changed\n" \
			 "Please report to linux-acpi@vger.kernel.org\n", str); \
} while (0)

static int act;
module_param(act, int, 0644);
MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");

static int crt;
module_param(crt, int, 0644);
MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");

static int tzp;
module_param(tzp, int, 0444);
MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");

static int off;
module_param(off, int, 0);
MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");

static int psv;
module_param(psv, int, 0644);
MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");

static struct workqueue_struct *acpi_thermal_pm_queue;

struct acpi_thermal_trip {
	unsigned long temp_dk;
	struct acpi_handle_list devices;
};

struct acpi_thermal_passive {
	struct acpi_thermal_trip trip;
	unsigned long tc1;
	unsigned long tc2;
	unsigned long delay;
};

struct acpi_thermal_active {
	struct acpi_thermal_trip trip;
};

struct acpi_thermal_trips {
	struct acpi_thermal_passive passive;
	struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
};

struct acpi_thermal {
	struct acpi_device *device;
	acpi_bus_id name;
	unsigned long temp_dk;
	unsigned long last_temp_dk;
	unsigned long polling_frequency;
	volatile u8 zombie;
	struct acpi_thermal_trips trips;
	struct thermal_trip *trip_table;
	struct thermal_zone_device *thermal_zone;
	int kelvin_offset;	/* in millidegrees */
	struct work_struct thermal_check_work;
	struct mutex thermal_check_lock;
	refcount_t thermal_check_count;
};

/* --------------------------------------------------------------------------
                             Thermal Zone Management
   -------------------------------------------------------------------------- */

static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
{
	acpi_status status = AE_OK;
	unsigned long long tmp;

	if (!tz)
		return -EINVAL;

	tz->last_temp_dk = tz->temp_dk;

	status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	tz->temp_dk = tmp;

	acpi_handle_debug(tz->device->handle, "Temperature is %lu dK\n",
			  tz->temp_dk);

	return 0;
}

static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
{
	acpi_status status = AE_OK;
	unsigned long long tmp;

	if (!tz)
		return -EINVAL;

	status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	tz->polling_frequency = tmp;
	acpi_handle_debug(tz->device->handle, "Polling frequency is %lu dS\n",
			  tz->polling_frequency);

	return 0;
}

static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k)
{
	if (temp_deci_k == THERMAL_TEMP_INVALID)
		return THERMAL_TEMP_INVALID;

	return deci_kelvin_to_millicelsius_with_offset(temp_deci_k,
						       tz->kelvin_offset);
}

static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip)
{
	return acpi_trip->temp_