1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2021 Thomas Weißschuh <thomas@weissschuh.net>
4 */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6
7 #include <linux/acpi.h>
8 #include <linux/hwmon.h>
9 #include <linux/module.h>
10 #include <linux/wmi.h>
11
12 #define GIGABYTE_WMI_GUID "DEADBEEF-2001-0000-00A0-C90629100000"
13 #define NUM_TEMPERATURE_SENSORS 6
14
15 static u8 usable_sensors_mask;
16
17 enum gigabyte_wmi_commandtype {
18 GIGABYTE_WMI_BUILD_DATE_QUERY = 0x1,
19 GIGABYTE_WMI_MAINBOARD_TYPE_QUERY = 0x2,
20 GIGABYTE_WMI_FIRMWARE_VERSION_QUERY = 0x4,
21 GIGABYTE_WMI_MAINBOARD_NAME_QUERY = 0x5,
22 GIGABYTE_WMI_TEMPERATURE_QUERY = 0x125,
23 };
24
25 struct gigabyte_wmi_args {
26 u32 arg1;
27 };
28
gigabyte_wmi_perform_query(struct wmi_device * wdev,enum gigabyte_wmi_commandtype command,struct gigabyte_wmi_args * args,struct acpi_buffer * out)29 static int gigabyte_wmi_perform_query(struct wmi_device *wdev,
30 enum gigabyte_wmi_commandtype command,
31 struct gigabyte_wmi_args *args, struct acpi_buffer *out)
32 {
33 const struct acpi_buffer in = {
34 .length = sizeof(*args),
35 .pointer = args,
36 };
37
38 acpi_status ret = wmidev_evaluate_method(wdev, 0x0, command, &in, out);
39
40 if (ACPI_FAILURE(ret))
41 return -EIO;
42
43 return 0;
44 }
45
gigabyte_wmi_query_integer(struct wmi_device * wdev,enum gigabyte_wmi_commandtype command,struct gigabyte_wmi_args * args,u64 * res)46 static int gigabyte_wmi_query_integer(struct wmi_device *wdev,
47 enum gigabyte_wmi_commandtype command,
48 struct gigabyte_wmi_args *args, u64 *res)
49 {
50 union acpi_object *obj;
51 struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
52 int ret;
53
54 ret = gigabyte_wmi_perform_query(wdev, command, args, &result);
55 if (ret)
56 return ret;
57 obj = result.pointer;
58 if (obj && obj->type == ACPI_TYPE_INTEGER)
59 *res = obj->integer.value;
60 else
61 ret = -EIO;
62 kfree(result.pointer);
63 return ret;
64 }
65
gigabyte_wmi_temperature(struct wmi_device * wdev,u8 sensor,long * res)66 static int gigabyte_wmi_temperature(struct wmi_device *wdev, u8 sensor, long *res)
67 {
68 struct gigabyte_wmi_args args = {
69 .arg1 = sensor,
70 };
71 u64 temp;
72 acpi_status ret;
73
74 ret = gigabyte_wmi_query_integer(wdev, GIGABYTE_WMI_TEMPERATURE_QUERY, &args, &temp);
75 if (ret == 0) {
76 if (temp == 0)
77 return -ENODEV;
78 *res = (s8)temp * 1000; // value is a signed 8-bit integer
79 }
80 return ret;
81 }
82
gigabyte_wmi_hwmon_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)83 static int gigabyte_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
84 u32 attr, int channel, long *val)
85 {
86 struct wmi_device *wdev = dev_get_drvdata(dev);
87
88 return gigabyte_wmi_temperature(wdev, channel, val);
89 }
90
gigabyte_wmi_hwmon_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)91 static umode_t gigabyte_wmi_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
92 u32 attr, int channel)
93 {
94 return usable_sensors_mask & BIT(channel) ? 0444 : 0;
95 }
96
97 static const struct hwmon_channel_info * const gigabyte_wmi_hwmon_info[] = {
98 HWMON_CHANNEL_INFO(temp,
99 HWMON_T_INPUT,
100 HWMON_T_INPUT,
101 HWMON_T_INPUT,
102 HWMON_T_INPUT,
103 HWMON_T_INPUT,
104 HWMON_T_INPUT),
105 NULL
106 };
107
108 static const struct hwmon_ops gigabyte_wmi_hwmon_ops = {
109 .read = gigabyte_wmi_hwmon_read,
110 .is_visible = gigabyte_wmi_hwmon_is_visible,
111 };
112
113 static const struct hwmon_chip_info gigabyte_wmi_hwmon_chip_info = {
114 .ops = &gigabyte_wmi_hwmon_ops,
115 .info = gigabyte_wmi_hwmon_info,
116 };
117
gigabyte_wmi_detect_sensor_usability(struct wmi_device * wdev)118 static u8 gigabyte_wmi_detect_sensor_usability(struct wmi_device *wdev)
119 {
120 int i;
121 long temp;
122 u8 r = 0;
123
124 for (i = 0; i < NUM_TEMPERATURE_SENSORS; i++) {
125 if (!gigabyte_wmi_temperature(wdev, i, &temp))
126 r |= BIT(i);
127 }
128 return r;
129 }
130
gigabyte_wmi_probe(struct wmi_device * wdev,const void * context)131 static int gigabyte_wmi_probe(struct wmi_device *wdev, const void *context)
132 {
133 struct device *hwmon_dev;
134
135 usable_sensors_mask = gigabyte_wmi_detect_sensor_usability(wdev);
136 if (!usable_sensors_mask) {
137 dev_info(&wdev->dev, "No temperature sensors usable");
138 return -ENODEV;
139 }
140
141 hwmon_dev = devm_hwmon_device_register_with_info(&wdev->dev, "gigabyte_wmi", wdev,
142 &gigabyte_wmi_hwmon_chip_info, NULL);
143
144 return PTR_ERR_OR_ZERO(hwmon_dev);
145 }
146
147 static const struct wmi_device_id gigabyte_wmi_id_table[] = {
148 { GIGABYTE_WMI_GUID, NULL },
149 { }
150 };
151
152 static struct wmi_driver gigabyte_wmi_driver = {
153 .driver = {
154 .name = "gigabyte-wmi",
155 },
156 .id_table = gigabyte_wmi_id_table,
157 .probe = gigabyte_wmi_probe,
158 };
159 module_wmi_driver(gigabyte_wmi_driver);
160
161 MODULE_DEVICE_TABLE(wmi, gigabyte_wmi_id_table);
162 MODULE_AUTHOR("Thomas Weißschuh <thomas@weissschuh.net>");
163 MODULE_DESCRIPTION("Gigabyte WMI temperature driver");
164 MODULE_LICENSE("GPL");
165