1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright 2023 Linaro Limited
4 * Copyright 2023 Intel Corporation
5 *
6 * Library routines for populating a generic thermal trip point structure
7 * with data obtained by evaluating a specific object in the ACPI Namespace.
8 */
9 #include <linux/acpi.h>
10 #include <linux/units.h>
11
12 #include "thermal_core.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 2180
22 #define TEMP_MAX_DECIK 4480
23
thermal_acpi_trip_temp(struct acpi_device * adev,char * obj_name,int * ret_temp)24 static int thermal_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 = deci_kelvin_to_millicelsius(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 /**
48 * thermal_acpi_active_trip_temp - Retrieve active trip point temperature
49 * @adev: Target thermal zone ACPI device object.
50 * @id: Active cooling level (0 - 9).
51 * @ret_temp: Address to store the retrieved temperature value on success.
52 *
53 * Evaluate the _ACx object for the thermal zone represented by @adev to obtain
54 * the temperature of the active cooling trip point corresponding to the active
55 * cooling level given by @id.
56 *
57 * Return 0 on success or a negative error value on failure.
58 */
thermal_acpi_active_trip_temp(struct acpi_device * adev,int id,int * ret_temp)59 int thermal_acpi_active_trip_temp(struct acpi_device *adev, int id, int *ret_temp)
60 {
61 char obj_name[] = {'_', 'A', 'C', '0' + id, '\0'};
62
63 if (id < 0 || id > 9)
64 return -EINVAL;
65
66 return thermal_acpi_trip_temp(adev, obj_name, ret_temp);
67 }
68 EXPORT_SYMBOL_GPL(thermal_acpi_active_trip_temp);
69
70 /**
71 * thermal_acpi_passive_trip_temp - Retrieve passive trip point temperature
72 * @adev: Target thermal zone ACPI device object.
73 * @ret_temp: Address to store the retrieved temperature value on success.
74 *
75 * Evaluate the _PSV object for the thermal zone represented by @adev to obtain
76 * the temperature of the passive cooling trip point.
77 *
78 * Return 0 on success or -ENODATA on failure.
79 */
thermal_acpi_passive_trip_temp(struct acpi_device * adev,int * ret_temp)80 int thermal_acpi_passive_trip_temp(struct acpi_device *adev, int *ret_temp)
81 {
82 return thermal_acpi_trip_temp(adev, "_PSV", ret_temp);
83 }
84 EXPORT_SYMBOL_GPL(thermal_acpi_passive_trip_temp);
85
86 /**
87 * thermal_acpi_hot_trip_temp - Retrieve hot trip point temperature
88 * @adev: Target thermal zone ACPI device object.
89 * @ret_temp: Address to store the retrieved temperature value on success.
90 *
91 * Evaluate the _HOT object for the thermal zone represented by @adev to obtain
92 * the temperature of the trip point at which the system is expected to be put
93 * into the S4 sleep state.
94 *
95 * Return 0 on success or -ENODATA on failure.
96 */
thermal_acpi_hot_trip_temp(struct acpi_device * adev,int * ret_temp)97 int thermal_acpi_hot_trip_temp(struct acpi_device *adev, int *ret_temp)
98 {
99 return thermal_acpi_trip_temp(adev, "_HOT", ret_temp);
100 }
101 EXPORT_SYMBOL_GPL(thermal_acpi_hot_trip_temp);
102
103 /**
104 * thermal_acpi_critical_trip_temp - Retrieve critical trip point temperature
105 * @adev: Target thermal zone ACPI device object.
106 * @ret_temp: Address to store the retrieved temperature value on success.
107 *
108 * Evaluate the _CRT object for the thermal zone represented by @adev to obtain
109 * the temperature of the critical cooling trip point.
110 *
111 * Return 0 on success or -ENODATA on failure.
112 */
thermal_acpi_critical_trip_temp(struct acpi_device * adev,int * ret_temp)113 int thermal_acpi_critical_trip_temp(struct acpi_device *adev, int *ret_temp)
114 {
115 return thermal_acpi_trip_temp(adev, "_CRT", ret_temp);
116 }
117 EXPORT_SYMBOL_GPL(thermal_acpi_critical_trip_temp);
118