Re: [PATCH 5/6] HID: asus: add microphone mute LED support for T3304

[Denis Benato <denis.benato@linux.dev>]

On 5/3/26 09:26, James Ye wrote:
> T3304 keyboard has a microphone mute LED indicator on the same key
> (Fn+F9). Look this up with a led_classdev.
>
> It does not have backlight LEDs, so return without failure from
> asus_kbd_register_leds if backlight support is not present.
>
> Signed-off-by: James Ye <jye836@gmail.com>
> ---
>  drivers/hid/hid-asus.c | 51 +++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 48 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index e4c97fddfaf1..4f68bc40b8bf 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -100,6 +100,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
>  #define QUIRK_ROG_ALLY_XPAD		BIT(13)
>  #define QUIRK_HID_FN_LOCK		BIT(14)
>  #define QUIRK_T3304_KEYBOARD		BIT(15)
> +#define QUIRK_HID_MICMUTE		BIT(16)
>  
Isn't QUIRK_T3304_KEYBOARD enough? Or are you saying you know there is more than one keyboard
model that requires this?
>  #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
>  						 QUIRK_NO_INIT_REPORTS | \
> @@ -144,6 +145,7 @@ struct asus_drvdata {
>  	unsigned long battery_next_query;
>  	struct work_struct fn_lock_sync_work;
>  	bool fn_lock;
> +	struct led_classdev led_micmute;
>  };
>  
>  static int asus_report_battery(struct asus_drvdata *, u8 *, int);
> @@ -578,6 +580,26 @@ static int asus_kbd_disable_oobe(struct hid_device *hdev)
>  	return 0;
>  }
>  
> +static int asus_kbd_set_micmute_led(struct hid_device *hdev, bool enabled)
> +{
> +	u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xd0, 0x7c, enabled };
> +
> +	return asus_kbd_set_report(hdev, buf, sizeof(buf));
> +}
> +
> +static int asus_led_brightness_set(struct led_classdev *led_cdev,
> +		enum led_brightness value)
> +{
> +	struct device *dev = led_cdev->dev->parent;
> +	struct hid_device *hdev = to_hid_device(dev);
> +	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
> +
> +	if (led_cdev == &drvdata->led_micmute)
> +		return asus_kbd_set_micmute_led(hdev, !!value);
> +
> +	return -ENODEV;
> +}
> +
>  static int asus_kbd_set_fn_lock(struct hid_device *hdev, bool enabled)
>  {
>  	u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xd0, 0x4e, !!enabled };
> @@ -752,9 +774,31 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
>  	if (ret < 0)
>  		return ret;
>  
> +	if (drvdata->quirks & QUIRK_HID_MICMUTE) {
> +		char *name_micmute;
> +		size_t name_sz = strlen(dev_name(&hdev->dev)) + 16;
> +
Do we really want to use strlen?

Do we really want to use strlen on the result of a function without additional checks?
> +		name_micmute = devm_kzalloc(&hdev->dev, name_sz, GFP_KERNEL);
> +		if (name_micmute == NULL)
> +			return -ENOMEM;
> +
> +		snprintf(name_micmute, name_sz, "%s::micmute", dev_name(&hdev->dev));
> +		drvdata->led_micmute.name = name_micmute;
> +		drvdata->led_micmute.default_trigger = "audio-micmute";
> +		drvdata->led_micmute.brightness_set_blocking = asus_led_brightness_set;
> +		drvdata->led_micmute.max_brightness = 1;
> +		drvdata->led_micmute.flags = LED_CORE_SUSPENDRESUME | LED_HW_PLUGGABLE;
> +		drvdata->led_micmute.dev = &hdev->dev;
> +		ret = devm_led_classdev_register(&hdev->dev, &drvdata->led_micmute);
> +		if (ret < 0) {
> +			hid_err(hdev, "Failed to register LED: %d.\n", ret);
> +			return ret;
> +		}
> +	}
> +
>  	/* Check for backlight support */
>  	if (!(kbd_func & SUPPORT_KBD_BACKLIGHT))
> -		return -ENODEV;
> +		return 0;
>  
This doesn't look like a good idea to change this for all laptops under the sun...


Perhaps might make sense to move this check before? Maybe not?

Denis
>  	if (dmi_match(DMI_PRODUCT_FAMILY, "ProArt P16")) {
>  		ret = asus_kbd_disable_oobe(hdev);
> @@ -1315,7 +1359,8 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  	}
>  
>  	/* Laptops keyboard backlight is always at 0x5a */
> -	if (is_vendor && (drvdata->quirks & QUIRK_USE_KBD_BACKLIGHT) &&
> +	if (is_vendor &&
> +	    (drvdata->quirks & (QUIRK_USE_KBD_BACKLIGHT | QUIRK_HID_MICMUTE)) &&
>  	    (asus_has_report_id(hdev, FEATURE_KBD_REPORT_ID)) &&
>  		(asus_kbd_register_leds(hdev)))
>  		hid_warn(hdev, "Failed to initialize backlight.\n");
> @@ -1587,7 +1632,7 @@ static const struct hid_device_id asus_devices[] = {
>  		USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_T101HA_KEYBOARD) },
>  	{ HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
>  		USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_T3304_KEYBOARD),
> -	  QUIRK_T3304_KEYBOARD },
> +	  QUIRK_T3304_KEYBOARD | QUIRK_HID_MICMUTE },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(hid, asus_devices);