// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2023 Linaro Limited
* Copyright 2023 Intel Corporation
*
* Library routines for retrieving trip point temperature values from the
* platform firmware via ACPI.
*/
#include <linux/acpi.h>
#include <linux/units.h>
#include <linux/thermal.h>
#include "internal.h"
/*
* Minimum temperature for full military grade is 218°K (-55°C) and
* max temperature is 448°K (175°C). We can consider those values as
* the boundaries for the [trips] temperature returned by the
* firmware. Any values out of these boundaries may be considered
* bogus and we can assume the firmware has no data to provide.
*/
#define TEMP_MIN_DECIK 2180ULL
#define TEMP_MAX_DECIK 4480ULL
static int acpi_trip_temp(struct acpi_device *adev, char *obj_name,
int *ret_temp)
{
unsigned long long temp;
acpi_status status;
status = acpi_evaluate_integer(adev->handle, obj_name, NULL, &temp);
if (ACPI_FAILURE(status)) {
acpi_handle_debug(adev->handle, "%s evaluation failed\n", obj_name);
return -ENODATA;
}
if (temp >= TEMP_MIN_DECIK && temp <= TEMP_MAX_DECIK) {
*ret_temp = temp;
} else {
acpi_handle_debug(adev->handle, "%s result %llu out of range\n",
obj_name, temp);
*ret_temp = THERMAL_TEMP_INVALID;
}
return 0;
}
int acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
{
char obj_name[] = {'_', 'A', 'C', '0' + id, '\0'};
if (id < 0 || id > 9)
return -EINVAL;
return acpi_trip_temp(adev, obj_name, ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_active_trip_temp, ACPI_THERMAL);
int acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
{
return acpi_trip_temp(adev, "_PSV", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_passive_trip_temp, ACPI_THERMAL);
int acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
{
return acpi_trip_temp(adev, "_HOT", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_hot_trip_temp, ACPI_THERMAL);
int acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
{
return acpi_trip_temp(adev, "_CRT", ret_temp);
}
EXPORT_SYMBOL_NS_GPL(acpi_critical_trip_temp, ACPI_THERMAL);
static int thermal_temp(int error, int temp_decik, int *ret_temp)
{
if (error)
return error;
if (temp_decik == THERMAL_TEMP_INVALID)
*ret_temp = THERMAL_TEMP_INVALID;
else
*ret_temp = deci_kelvin_to_millicelsius(temp_decik);
return 0;
}
/**
* thermal_acpi_active_trip_temp - Retrieve active trip point temperature
* @adev: Target thermal zone ACPI device object.
* @id: Active cooling level (0 - 9).
* @ret_temp: Address to store the retrieved temperature value on success.
*
* Evaluate the _ACx object for the thermal zone represented by @adev to obtain
* the temperature of the active cooling trip point corresponding to the active
* cooling level given by @id.
*
* Return 0 on success or a negative error value on failure.
*/
int thermal_acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
{
int temp_decik;
int ret = acpi_active_trip_temp(adev, id, &temp_decik);
return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_active_trip_temp);
/**
* thermal_acpi_passive_trip_temp - Retrieve passive trip point temperature
* @adev: Target thermal zone ACPI device object.
* @ret_temp: Address to store the retrieved temperature value on success.
*
* Evaluate the _PSV object for the thermal zone represented by @adev to obtain
* the temperature of the passive cooling trip point.
*
* Return 0 on success or -ENODATA on failure.
*/
int thermal_acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
{
int temp_decik;
int ret = acpi_passive_trip_temp(adev, &temp_decik);
return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_passive_trip_temp);
/**
* thermal_acpi_hot_trip_temp - Retrieve hot trip point temperature
* @adev: Target thermal zone ACPI device object.
* @ret_temp: Address to store the retrieved temperature value on success.
*
* Evaluate the _HOT object for the thermal zone represented by @adev to obtain
* the temperature of the trip point at which the system is expected to be put
* into the S4 sleep state.
*
* Return 0 on success or -ENODATA on failure.
*/
int thermal_acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
{
int temp_decik;
int ret = acpi_hot_trip_temp(adev, &temp_decik);
return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_hot_trip_temp);
/**
* thermal_acpi_critical_trip_temp - Retrieve critical trip point temperature
* @adev: Target thermal zone ACPI device object.
* @ret_temp: Address to store the retrieved temperature value on success.
*
* Evaluate the _CRT object for the thermal zone represented by @adev to obtain
* the temperature of the critical cooling trip point.
*
* Return 0 on success or -ENODATA on failure.
*/
int thermal_acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
{
int temp_decik;
int ret = acpi_critical_trip_temp(adev, &temp_decik);
return thermal_temp(ret, temp_decik, ret_temp);
}
EXPORT_SYMBOL_GPL(thermal_acpi_critical_trip_temp);
