drivers/acpi/thermal_lib.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2023 Linaro Limited
   4  * Copyright 2023 Intel Corporation
   5  *
   6  * Library routines for retrieving trip point temperature values from the
   7  * platform firmware via ACPI.
   8  */
   9 #include <linux/acpi.h>
  10 #include <linux/units.h>
  11 #include <linux/thermal.h>
  12 #include "internal.h"
  13
  14 /*
  15  * Minimum temperature for full military grade is 218°K (-55°C) and
  16  * max temperature is 448°K (175°C). We can consider those values as
  17  * the boundaries for the [trips] temperature returned by the
  18  * firmware. Any values out of these boundaries may be considered
  19  * bogus and we can assume the firmware has no data to provide.
  20  */
  21 #define TEMP_MIN_DECIK  2180ULL
  22 #define TEMP_MAX_DECIK  4480ULL
  23
  24 static int acpi_trip_temp(struct acpi_device *adev, char *obj_name,
  25                           int *ret_temp)
  26 {
  27         unsigned long long temp;
  28         acpi_status status;
  29
  30         status = acpi_evaluate_integer(adev->handle, obj_name, NULL, &temp);
  31         if (ACPI_FAILURE(status)) {
  32                 acpi_handle_debug(adev->handle, "%s evaluation failed\n", obj_name);
  33                 return -ENODATA;
  34         }
  35
  36         if (temp >= TEMP_MIN_DECIK && temp <= TEMP_MAX_DECIK) {
  37                 *ret_temp = temp;
  38         } else {
  39                 acpi_handle_debug(adev->handle, "%s result %llu out of range\n",
  40                                   obj_name, temp);
  41                 *ret_temp = THERMAL_TEMP_INVALID;
  42         }
  43
  44         return 0;
  45 }
  46
  47 int acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
  48 {
  49         char obj_name[] = {'_', 'A', 'C', '0' + id, '\0'};
  50
  51         if (id < 0 || id > 9)
  52                 return -EINVAL;
  53
  54         return acpi_trip_temp(adev, obj_name, ret_temp);
  55 }
  56 EXPORT_SYMBOL_NS_GPL(acpi_active_trip_temp, "ACPI_THERMAL");
  57
  58 int acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
  59 {
  60         return acpi_trip_temp(adev, "_PSV", ret_temp);
  61 }
  62 EXPORT_SYMBOL_NS_GPL(acpi_passive_trip_temp, "ACPI_THERMAL");
  63
  64 int acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
  65 {
  66         return acpi_trip_temp(adev, "_HOT", ret_temp);
  67 }
  68 EXPORT_SYMBOL_NS_GPL(acpi_hot_trip_temp, "ACPI_THERMAL");
  69
  70 int acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
  71 {
  72         return acpi_trip_temp(adev, "_CRT", ret_temp);
  73 }
  74 EXPORT_SYMBOL_NS_GPL(acpi_critical_trip_temp, "ACPI_THERMAL");
  75
  76 static int thermal_temp(int error, int temp_decik, int *ret_temp)
  77 {
  78         if (error)
  79                 return error;
  80
  81         if (temp_decik == THERMAL_TEMP_INVALID)
  82                 *ret_temp = THERMAL_TEMP_INVALID;
  83         else
  84                 *ret_temp = deci_kelvin_to_millicelsius(temp_decik);
  85
  86         return 0;
  87 }
  88
  89 /**
  90  * thermal_acpi_active_trip_temp - Retrieve active trip point temperature
  91  * @adev: Target thermal zone ACPI device object.
  92  * @id: Active cooling level (0 - 9).
  93  * @ret_temp: Address to store the retrieved temperature value on success.
  94  *
  95  * Evaluate the _ACx object for the thermal zone represented by @adev to obtain
  96  * the temperature of the active cooling trip point corresponding to the active
  97  * cooling level given by @id.
  98  *
  99  * Return 0 on success or a negative error value on failure.
 100  */
 101 int thermal_acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
 102 {
 103         int temp_decik = 0;
 104         int ret = acpi_active_trip_temp(adev, id, &temp_decik);
 105
 106         return thermal_temp(ret, temp_decik, ret_temp);
 107 }
 108 EXPORT_SYMBOL_GPL(thermal_acpi_active_trip_temp);
 109
 110 /**
 111  * thermal_acpi_passive_trip_temp - Retrieve passive trip point temperature
 112  * @adev: Target thermal zone ACPI device object.
 113  * @ret_temp: Address to store the retrieved temperature value on success.
 114  *
 115  * Evaluate the _PSV object for the thermal zone represented by @adev to obtain
 116  * the temperature of the passive cooling trip point.
 117  *
 118  * Return 0 on success or -ENODATA on failure.
 119  */
 120 int thermal_acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
 121 {
 122         int temp_decik = 0;
 123         int ret = acpi_passive_trip_temp(adev, &temp_decik);
 124
 125         return thermal_temp(ret, temp_decik, ret_temp);
 126 }
 127 EXPORT_SYMBOL_GPL(thermal_acpi_passive_trip_temp);
 128
 129 /**
 130  * thermal_acpi_hot_trip_temp - Retrieve hot trip point temperature
 131  * @adev: Target thermal zone ACPI device object.
 132  * @ret_temp: Address to store the retrieved temperature value on success.
 133  *
 134  * Evaluate the _HOT object for the thermal zone represented by @adev to obtain
 135  * the temperature of the trip point at which the system is expected to be put
 136  * into the S4 sleep state.
 137  *
 138  * Return 0 on success or -ENODATA on failure.
 139  */
 140 int thermal_acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
 141 {
 142         int temp_decik = 0;
 143         int ret = acpi_hot_trip_temp(adev, &temp_decik);
 144
 145         return thermal_temp(ret, temp_decik, ret_temp);
 146 }
 147 EXPORT_SYMBOL_GPL(thermal_acpi_hot_trip_temp);
 148
 149 /**
 150  * thermal_acpi_critical_trip_temp - Retrieve critical trip point temperature
 151  * @adev: Target thermal zone ACPI device object.
 152  * @ret_temp: Address to store the retrieved temperature value on success.
 153  *
 154  * Evaluate the _CRT object for the thermal zone represented by @adev to obtain
 155  * the temperature of the critical cooling trip point.
 156  *
 157  * Return 0 on success or -ENODATA on failure.
 158  */
 159 int thermal_acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
 160 {
 161         int temp_decik = 0;
 162         int ret = acpi_critical_trip_temp(adev, &temp_decik);
 163
 164         return thermal_temp(ret, temp_decik, ret_temp);
 165 }
 166 EXPORT_SYMBOL_GPL(thermal_acpi_critical_trip_temp);