--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 Thomas Weißschuh <thomas@weissschuh.net>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/dmi.h>
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/wmi.h>
+
+#define GIGABYTE_WMI_GUID "DEADBEEF-2001-0000-00A0-C90629100000"
+#define NUM_TEMPERATURE_SENSORS 6
+
+static bool force_load;
+module_param(force_load, bool, 0444);
+MODULE_PARM_DESC(force_load, "Force loading on unknown platform");
+
+static u8 usable_sensors_mask;
+
+enum gigabyte_wmi_commandtype {
+ GIGABYTE_WMI_BUILD_DATE_QUERY = 0x1,
+ GIGABYTE_WMI_MAINBOARD_TYPE_QUERY = 0x2,
+ GIGABYTE_WMI_FIRMWARE_VERSION_QUERY = 0x4,
+ GIGABYTE_WMI_MAINBOARD_NAME_QUERY = 0x5,
+ GIGABYTE_WMI_TEMPERATURE_QUERY = 0x125,
+};
+
+struct gigabyte_wmi_args {
+ u32 arg1;
+};
+
+static int gigabyte_wmi_perform_query(struct wmi_device *wdev,
+ enum gigabyte_wmi_commandtype command,
+ struct gigabyte_wmi_args *args, struct acpi_buffer *out)
+{
+ const struct acpi_buffer in = {
+ .length = sizeof(*args),
+ .pointer = args,
+ };
+
+ acpi_status ret = wmidev_evaluate_method(wdev, 0x0, command, &in, out);
+
+ if (ACPI_FAILURE(ret))
+ return -EIO;
+
+ return 0;
+}
+
+static int gigabyte_wmi_query_integer(struct wmi_device *wdev,
+ enum gigabyte_wmi_commandtype command,
+ struct gigabyte_wmi_args *args, u64 *res)
+{
+ union acpi_object *obj;
+ struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
+ int ret;
+
+ ret = gigabyte_wmi_perform_query(wdev, command, args, &result);
+ if (ret)
+ return ret;
+ obj = result.pointer;
+ if (obj && obj->type == ACPI_TYPE_INTEGER)
+ *res = obj->integer.value;
+ else
+ ret = -EIO;
+ kfree(result.pointer);
+ return ret;
+}
+
+static int gigabyte_wmi_temperature(struct wmi_device *wdev, u8 sensor, long *res)
+{
+ struct gigabyte_wmi_args args = {
+ .arg1 = sensor,
+ };
+ u64 temp;
+ acpi_status ret;
+
+ ret = gigabyte_wmi_query_integer(wdev, GIGABYTE_WMI_TEMPERATURE_QUERY, &args, &temp);
+ if (ret == 0) {
+ if (temp == 0)
+ return -ENODEV;
+ *res = (s8)temp * 1000; // value is a signed 8-bit integer
+ }
+ return ret;
+}
+
+static int gigabyte_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct wmi_device *wdev = dev_get_drvdata(dev);
+
+ return gigabyte_wmi_temperature(wdev, channel, val);
+}
+
+static umode_t gigabyte_wmi_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ return usable_sensors_mask & BIT(channel) ? 0444 : 0;
+}
+
+static const struct hwmon_channel_info *gigabyte_wmi_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops gigabyte_wmi_hwmon_ops = {
+ .read = gigabyte_wmi_hwmon_read,
+ .is_visible = gigabyte_wmi_hwmon_is_visible,
+};
+
+static const struct hwmon_chip_info gigabyte_wmi_hwmon_chip_info = {
+ .ops = &gigabyte_wmi_hwmon_ops,
+ .info = gigabyte_wmi_hwmon_info,
+};
+
+static u8 gigabyte_wmi_detect_sensor_usability(struct wmi_device *wdev)
+{
+ int i;
+ long temp;
+ u8 r = 0;
+
+ for (i = 0; i < NUM_TEMPERATURE_SENSORS; i++) {
+ if (!gigabyte_wmi_temperature(wdev, i, &temp))
+ r |= BIT(i);
+ }
+ return r;
+}
+
+static const struct dmi_system_id gigabyte_wmi_known_working_platforms[] = {
+ { .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "B550 GAMING X V2"),
+ }},
+ { .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "B550M DS3H"),
+ }},
+ { .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "Z390 I AORUS PRO WIFI-CF"),
+ }},
+ { .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "X570 I AORUS PRO WIFI"),
+ }},
+ { }
+};
+
+static int gigabyte_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+ struct device *hwmon_dev;
+
+ if (!dmi_check_system(gigabyte_wmi_known_working_platforms)) {
+ if (!force_load)
+ return -ENODEV;
+ dev_warn(&wdev->dev, "Forcing load on unknown platform");
+ }
+
+ usable_sensors_mask = gigabyte_wmi_detect_sensor_usability(wdev);
+ if (!usable_sensors_mask) {
+ dev_info(&wdev->dev, "No temperature sensors usable");
+ return -ENODEV;
+ }
+
+ hwmon_dev = devm_hwmon_device_register_with_info(&wdev->dev, "gigabyte_wmi", wdev,
+ &gigabyte_wmi_hwmon_chip_info, NULL);
+
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct wmi_device_id gigabyte_wmi_id_table[] = {
+ { GIGABYTE_WMI_GUID, NULL },
+ { }
+};
+
+static struct wmi_driver gigabyte_wmi_driver = {
+ .driver = {
+ .name = "gigabyte-wmi",
+ },
+ .id_table = gigabyte_wmi_id_table,
+ .probe = gigabyte_wmi_probe,
+};
+module_wmi_driver(gigabyte_wmi_driver);
+
+MODULE_DEVICE_TABLE(wmi, gigabyte_wmi_id_table);
+MODULE_AUTHOR("Thomas Weißschuh <thomas@weissschuh.net>");
+MODULE_DESCRIPTION("Gigabyte WMI temperature driver");
+MODULE_LICENSE("GPL");