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(handle: adev->handle, pathname: obj_name, NULL, data: &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, obj_name: "_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, obj_name: "_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, obj_name: "_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(t: 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(error: 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(error: 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(error: 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(error: ret, temp_decik, ret_temp); |
165 | } |
166 | EXPORT_SYMBOL_GPL(thermal_acpi_critical_trip_temp); |
167 | |