platform/x86: add Gigabyte WMI temperature driver

Tested with
* X570 I Aorus Pro Wifi (rev 1.0)
* B550M DS3H
* B550 Gaming X V2 (rev.1.x)
* Z390 I AORUS PRO WIFI (rev. 1.0)

Those mainboards contain an ITE chips for management and
monitoring.

They could also be handled by drivers/hwmon/i87.c.
But the SuperIO range used by i87 is already claimed and used by the
firmware.

The following warning is printed at boot:

kernel: ACPI Warning: SystemIO range 0x0000000000000A45-0x0000000000000A46 conflicts with OpRegion 0x0000000000000A45-0x0000000000000A46 (\GSA1.SIO1) (20200528/utaddress-204)
kernel: ACPI: This conflict may cause random problems and system instability
kernel: ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver

This driver implements such an ACPI driver.

Unfortunately not all sensor registers are handled by the firmware and even
less are exposed via WMI.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210412123513.628901-1-linux@weissschuh.net
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

3 files changed, 207 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 53973ee59bf7..697fc446ac41 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -123,6 +123,17 @@ config XIAOMI_WMI
 	  To compile this driver as a module, choose M here: the module will
 	  be called xiaomi-wmi.
 
+config GIGABYTE_WMI
+	tristate "Gigabyte WMI temperature driver"
+	depends on ACPI_WMI
+	depends on HWMON
+	help
+	  Say Y here if you want to support WMI-based temperature reporting on
+	  Gigabyte mainboards.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gigabyte-wmi.
+
 config ACERHDF
 	tristate "Acer Aspire One temperature and fan driver"
 	depends on ACPI && THERMAL
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 3e364941e8a7..dcc8cdb95b4d 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT)	+= intel-wmi-thunderbolt.o
 obj-$(CONFIG_MXM_WMI)			+= mxm-wmi.o
 obj-$(CONFIG_PEAQ_WMI)			+= peaq-wmi.o
 obj-$(CONFIG_XIAOMI_WMI)		+= xiaomi-wmi.o
+obj-$(CONFIG_GIGABYTE_WMI)		+= gigabyte-wmi.o
 
 # Acer
 obj-$(CONFIG_ACERHDF)		+= acerhdf.o
diff --git a/drivers/platform/x86/gigabyte-wmi.c b/drivers/platform/x86/gigabyte-wmi.c
new file mode 100644
index 000000000000..bb1b0b205fa7
--- /dev/null
+++ b/drivers/platform/x86/gigabyte-wmi.c
@@ -0,0 +1,195 @@
+// 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");