1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <acpi/acpigen.h>
4 #include <assert.h>
5 #include <commonlib/bsd/helpers.h>
6 #include <console/console.h>
7 #include <device/device.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10
11 #include "chip.h"
12
13 #define TZ_DEVICE_PATH "\\_TZ"
14 /* These defaults should be good enough for most systems */
15 #define DEFAULT_TC1 2
16 #define DEFAULT_TC2 5
17 #define DEFAULT_TSP 10
18
19 #define CELSIUS_TO_DECI_KELVIN(temp_c) ((temp_c) * 10 + 2732)
20 #define SECONDS_TO_DECI_SECONDS(s) ((s) * 10)
21
thermal_zone_acpi_name(const struct device * dev)22 static const char *thermal_zone_acpi_name(const struct device *dev)
23 {
24 char *name;
25
26 if (dev->path.type != DEVICE_PATH_GENERIC)
27 return NULL;
28
29 name = malloc(ACPI_NAME_BUFFER_SIZE);
30 snprintf(name, ACPI_NAME_BUFFER_SIZE, "TM%02X", dev->path.generic.id);
31
32 return name;
33 }
34
thermal_zone_fill_ssdt(const struct device * dev)35 static void thermal_zone_fill_ssdt(const struct device *dev)
36 {
37 struct drivers_acpi_thermal_zone_config *config = config_of(dev);
38 const char *scope;
39 const char *name;
40
41 assert(dev->path.type == DEVICE_PATH_GENERIC);
42
43 if (config->use_acpi1_thermal_zone_scope)
44 scope = TZ_DEVICE_PATH;
45 else
46 scope = acpi_device_scope(dev);
47
48 name = acpi_device_name(dev);
49
50 assert(name);
51 assert(scope);
52
53 if (!config->temperature_controller) {
54 printk(BIOS_ERR, "%s: missing temperature_controller\n", dev_path(dev));
55 return;
56 }
57
58 printk(BIOS_INFO, "%s.%s: %s at %s\n", scope, name, dev->chip_ops->name, dev_path(dev));
59
60 acpigen_write_scope(scope);
61 acpigen_write_thermal_zone(name);
62
63 if (config->description)
64 acpigen_write_name_unicode("_STR", config->description);
65
66 if (config->polling_period)
67 acpigen_write_name_integer(
68 "_TZP", SECONDS_TO_DECI_SECONDS(config->polling_period));
69
70 if (config->critical_temperature)
71 acpigen_write_name_integer(
72 "_CRT", CELSIUS_TO_DECI_KELVIN(config->critical_temperature));
73
74 if (config->hibernate_temperature)
75 acpigen_write_name_integer(
76 "_HOT", CELSIUS_TO_DECI_KELVIN(config->hibernate_temperature));
77
78 if (config->passive_config.temperature) {
79 acpigen_write_name_integer(
80 "_PSV", CELSIUS_TO_DECI_KELVIN(config->passive_config.temperature));
81
82 /*
83 * The linux kernel currently has an artificial limit of 10 on the number of
84 * references that can be returned in a list. If we don't respect this limit,
85 * then the passive threshold won't work.
86 *
87 * See https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/third_party/kernel/v5.10/include/acpi/acpi_bus.h;l=19
88 */
89 acpigen_write_processor_package("_PSL", 0, MIN(10, dev_count_cpu()));
90
91 acpigen_write_name_integer("_TC1", config->passive_config.time_constant_1
92 ?: DEFAULT_TC1);
93 acpigen_write_name_integer("_TC2", config->passive_config.time_constant_2
94 ?: DEFAULT_TC2);
95 acpigen_write_name_integer(
96 "_TSP",
97 SECONDS_TO_DECI_SECONDS(config->passive_config.time_sampling_period
98 ?: DEFAULT_TSP));
99 }
100
101 /*
102 * Method (_TMP) {
103 * Return (<path>.TMP(<sensor_id>))
104 * }
105 */
106 acpigen_write_method_serialized("_TMP", 0);
107 acpigen_emit_byte(RETURN_OP);
108 acpigen_emit_namestring(acpi_device_path_join(config->temperature_controller, "TMP"));
109 acpigen_write_integer(config->sensor_id);
110 acpigen_write_method_end();
111
112 acpigen_write_thermal_zone_end();
113 acpigen_write_scope_end();
114 }
115
116 static struct device_operations thermal_zone_ops = {
117 .read_resources = noop_read_resources,
118 .set_resources = noop_set_resources,
119 .acpi_name = thermal_zone_acpi_name,
120 .acpi_fill_ssdt = thermal_zone_fill_ssdt,
121 };
122
thermal_zone_enable_dev(struct device * dev)123 static void thermal_zone_enable_dev(struct device *dev)
124 {
125 dev->ops = &thermal_zone_ops;
126 }
127
128 struct chip_operations drivers_acpi_thermal_zone_ops = {
129 .name = "ACPI Thermal Zone",
130 .enable_dev = thermal_zone_enable_dev,
131 };
132