drivers/platform/x86/gigabyte-wmi.c

   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
  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
  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
  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
  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
  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
 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
 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");