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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2021 Thomas Weißschuh <thomas@weissschuh.net>4 */5#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt6 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 614 15static u8 usable_sensors_mask;16 17enum 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 25struct gigabyte_wmi_args {26 u32 arg1;27};28 29static 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 46static 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 else61 ret = -EIO;62 kfree(result.pointer);63 return ret;64}65 66static 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 integer79 }80 return ret;81}82 83static 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 91static 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 97static 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 NULL106};107 108static const struct hwmon_ops gigabyte_wmi_hwmon_ops = {109 .read = gigabyte_wmi_hwmon_read,110 .is_visible = gigabyte_wmi_hwmon_is_visible,111};112 113static const struct hwmon_chip_info gigabyte_wmi_hwmon_chip_info = {114 .ops = &gigabyte_wmi_hwmon_ops,115 .info = gigabyte_wmi_hwmon_info,116};117 118static 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 131static 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 147static const struct wmi_device_id gigabyte_wmi_id_table[] = {148 { GIGABYTE_WMI_GUID, NULL },149 { }150};151 152static 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};159module_wmi_driver(gigabyte_wmi_driver);160 161MODULE_DEVICE_TABLE(wmi, gigabyte_wmi_id_table);162MODULE_AUTHOR("Thomas Weißschuh <thomas@weissschuh.net>");163MODULE_DESCRIPTION("Gigabyte WMI temperature driver");164MODULE_LICENSE("GPL");165