platform/x86:lenovo-wmi-hotkey-utilities.c: Support for mic and audio mute LEDs

Implement Lenovo utility data WMI calls needed to make LEDs
work on Ideapads that support this GUID.
This enables the mic and audio LEDs to be updated correctly.

Tested on below samples.
ThinkBook 13X Gen4 IMH
ThinkBook 14 G6 ABP
ThinkBook 16p Gen4-21J8
ThinkBook 16 G8 IRL
ThinkBook 16 G7+ ASP

Signed-off-by: Jackie Dong <xy-jackie@139.com>
Suggested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Kurt Borja <kuurtb@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20250222114532.4105-1-xy-jackie@139.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

MAINTAINERS

@@ -13158,6 +13158,12 @@ S:	Maintained
 W:	http://legousb.sourceforge.net/
 F:	drivers/usb/misc/legousbtower.c
 
+LENOVO WMI HOTKEY UTILITIES DRIVER
+M:	Jackie Dong <xy-jackie@139.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+F:	drivers/platform/x86/lenovo-wmi-hotkey-utilities.c
+
 LETSKETCH HID TABLET DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>
 L:	linux-input@vger.kernel.org

drivers/platform/x86/Kconfig

@@ -475,6 +475,17 @@ config IDEAPAD_LAPTOP
 	  This is a driver for Lenovo IdeaPad netbooks contains drivers for
 	  rfkill switch, hotkey, fan control and backlight control.
 
+config LENOVO_WMI_HOTKEY_UTILITIES
+	tristate "Lenovo Hotkey Utility WMI extras driver"
+	depends on ACPI_WMI
+	select NEW_LEDS
+	select LEDS_CLASS
+	imply IDEAPAD_LAPTOP
+	help
+	  This driver provides WMI support for Lenovo customized hotkeys function,
+	  such as LED control for audio/mic mute event for Ideapad, YOGA, XiaoXin,
+	  Gaming, ThinkBook and so on.
+
 config LENOVO_YMC
 	tristate "Lenovo Yoga Tablet Mode Control"
 	depends on ACPI_WMI

drivers/platform/x86/Makefile

@@ -61,6 +61,7 @@ obj-$(CONFIG_UV_SYSFS)       += uv_sysfs.o
 # IBM Thinkpad and Lenovo
 obj-$(CONFIG_IBM_RTL)		+= ibm_rtl.o
 obj-$(CONFIG_IDEAPAD_LAPTOP)	+= ideapad-laptop.o
+obj-$(CONFIG_LENOVO_WMI_HOTKEY_UTILITIES)	+= lenovo-wmi-hotkey-utilities.o
 obj-$(CONFIG_LENOVO_YMC)	+= lenovo-ymc.o
 obj-$(CONFIG_SENSORS_HDAPS)	+= hdaps.o
 obj-$(CONFIG_THINKPAD_ACPI)	+= thinkpad_acpi.o

drivers/platform/x86/lenovo-wmi-hotkey-utilities.c

@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Lenovo Super Hotkey Utility WMI extras driver for Ideapad laptop
+ *
+ *  Copyright (C) 2025	Lenovo
+ */
+
+#include <linux/cleanup.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/wmi.h>
+
+/* Lenovo Super Hotkey WMI GUIDs */
+#define LUD_WMI_METHOD_GUID	"CE6C0974-0407-4F50-88BA-4FC3B6559AD8"
+
+/* Lenovo Utility Data WMI method_id */
+#define WMI_LUD_GET_SUPPORT 1
+#define WMI_LUD_SET_FEATURE 2
+
+#define WMI_LUD_GET_MICMUTE_LED_VER   20
+#define WMI_LUD_GET_AUDIOMUTE_LED_VER 26
+
+#define WMI_LUD_SUPPORT_MICMUTE_LED_VER   25
+#define WMI_LUD_SUPPORT_AUDIOMUTE_LED_VER 27
+
+/* Input parameters to mute/unmute audio LED and Mic LED */
+struct wmi_led_args {
+	u8 id;
+	u8 subid;
+	u16 value;
+};
+
+/* Values of input parameters to SetFeature of audio LED and Mic LED */
+enum hotkey_set_feature {
+	MIC_MUTE_LED_ON		= 1,
+	MIC_MUTE_LED_OFF	= 2,
+	AUDIO_MUTE_LED_ON	= 4,
+	AUDIO_MUTE_LED_OFF	= 5,
+};
+
+#define LSH_ACPI_LED_MAX 2
+
+struct lenovo_super_hotkey_wmi_private {
+	struct led_classdev cdev[LSH_ACPI_LED_MAX];
+	struct wmi_device *led_wdev;
+};
+
+enum mute_led_type {
+	MIC_MUTE,
+	AUDIO_MUTE,
+};
+
+static int lsh_wmi_mute_led_set(enum mute_led_type led_type, struct led_classdev *led_cdev,
+				enum led_brightness brightness)
+
+{
+	struct lenovo_super_hotkey_wmi_private *wpriv = container_of(led_cdev,
+			struct lenovo_super_hotkey_wmi_private, cdev[led_type]);
+	struct wmi_led_args led_arg = {0, 0, 0};
+	struct acpi_buffer input;
+	acpi_status status;
+
+	switch (led_type) {
+	case MIC_MUTE:
+		led_arg.id = brightness == LED_ON ? MIC_MUTE_LED_ON : MIC_MUTE_LED_OFF;
+		break;
+	case AUDIO_MUTE:
+		led_arg.id = brightness == LED_ON ? AUDIO_MUTE_LED_ON : AUDIO_MUTE_LED_OFF;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	input.length = sizeof(led_arg);
+	input.pointer = &led_arg;
+	status = wmidev_evaluate_method(wpriv->led_wdev, 0, WMI_LUD_SET_FEATURE, &input, NULL);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return 0;
+}
+
+static int lsh_wmi_audiomute_led_set(struct led_classdev *led_cdev,
+				     enum led_brightness brightness)
+
+{
+	return lsh_wmi_mute_led_set(AUDIO_MUTE, led_cdev, brightness);
+}
+
+static int lsh_wmi_micmute_led_set(struct led_classdev *led_cdev,
+				   enum led_brightness brightness)
+{
+	return lsh_wmi_mute_led_set(MIC_MUTE, led_cdev, brightness);
+}
+
+static int lenovo_super_hotkey_wmi_led_init(enum mute_led_type led_type, struct device *dev)
+{
+	struct lenovo_super_hotkey_wmi_private *wpriv = dev_get_drvdata(dev);
+	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_buffer input;
+	int led_version, err = 0;
+	unsigned int wmiarg;
+	acpi_status status;
+
+	switch (led_type) {
+	case MIC_MUTE:
+		wmiarg = WMI_LUD_GET_MICMUTE_LED_VER;
+		break;
+	case AUDIO_MUTE:
+		wmiarg = WMI_LUD_GET_AUDIOMUTE_LED_VER;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	input.length = sizeof(wmiarg);
+	input.pointer = &wmiarg;
+	status = wmidev_evaluate_method(wpriv->led_wdev, 0, WMI_LUD_GET_SUPPORT, &input, &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	union acpi_object *obj __free(kfree) = output.pointer;
+	if (obj && obj->type == ACPI_TYPE_INTEGER)
+		led_version = obj->integer.value;
+	else
+		return -EIO;
+
+	wpriv->cdev[led_type].max_brightness = LED_ON;
+	wpriv->cdev[led_type].flags = LED_CORE_SUSPENDRESUME;
+
+	switch (led_type) {
+	case MIC_MUTE:
+		if (led_version != WMI_LUD_SUPPORT_MICMUTE_LED_VER)
+			return -EIO;
+
+		wpriv->cdev[led_type].name = "platform::micmute";
+		wpriv->cdev[led_type].brightness_set_blocking = &lsh_wmi_micmute_led_set;
+		wpriv->cdev[led_type].default_trigger = "audio-micmute";
+		break;
+	case AUDIO_MUTE:
+		if (led_version != WMI_LUD_SUPPORT_AUDIOMUTE_LED_VER)
+			return -EIO;
+
+		wpriv->cdev[led_type].name = "platform::mute";
+		wpriv->cdev[led_type].brightness_set_blocking = &lsh_wmi_audiomute_led_set;
+		wpriv->cdev[led_type].default_trigger = "audio-mute";
+		break;
+	default:
+		dev_err(dev, "Unknown LED type %d\n", led_type);
+		return -EINVAL;
+	}
+
+	err = devm_led_classdev_register(dev, &wpriv->cdev[led_type]);
+	if (err < 0) {
+		dev_err(dev, "Could not register mute LED %d : %d\n", led_type, err);
+		return err;
+	}
+	return 0;
+}
+
+static int lenovo_super_hotkey_wmi_leds_setup(struct device *dev)
+{
+	int err;
+
+	err = lenovo_super_hotkey_wmi_led_init(MIC_MUTE, dev);
+	if (err)
+		return err;
+
+	err = lenovo_super_hotkey_wmi_led_init(AUDIO_MUTE, dev);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int lenovo_super_hotkey_wmi_probe(struct wmi_device *wdev, const void *context)
+{
+	struct lenovo_super_hotkey_wmi_private *wpriv;
+
+	wpriv = devm_kzalloc(&wdev->dev, sizeof(*wpriv), GFP_KERNEL);
+	if (!wpriv)
+		return -ENOMEM;
+
+	dev_set_drvdata(&wdev->dev, wpriv);
+	wpriv->led_wdev = wdev;
+	return lenovo_super_hotkey_wmi_leds_setup(&wdev->dev);
+}
+
+static const struct wmi_device_id lenovo_super_hotkey_wmi_id_table[] = {
+	{ LUD_WMI_METHOD_GUID, NULL }, /* Utility data */
+	{ }
+};
+
+MODULE_DEVICE_TABLE(wmi, lenovo_super_hotkey_wmi_id_table);
+
+static struct wmi_driver lenovo_wmi_hotkey_utilities_driver = {
+	 .driver = {
+		 .name = "lenovo_wmi_hotkey_utilities",
+		 .probe_type = PROBE_PREFER_ASYNCHRONOUS
+	 },
+	 .id_table = lenovo_super_hotkey_wmi_id_table,
+	 .probe = lenovo_super_hotkey_wmi_probe,
+	 .no_singleton = true,
+};
+
+module_wmi_driver(lenovo_wmi_hotkey_utilities_driver);
+
+MODULE_AUTHOR("Jackie Dong <dongeg1@lenovo.com>");
+MODULE_DESCRIPTION("Lenovo Super Hotkey Utility WMI extras driver");
+MODULE_LICENSE("GPL");