Re: [PATCH v3 07/10] platform/x86: asus-wmi: add keyboard brightness event handler

["Luke D. Jones" <luke@ljones.dev>]

On 22/03/25 23:28, Antheas Kapenekakis wrote:
> Currenlty, the keyboard brightness control of Asus WMI keyboards is
> handled in the kernel, which leads to the shortcut going from
> brightness 0, to 1, to 2, and 3.
> 
> However, for HID keyboards it is exposed as a key and handled by the
> user's desktop environment. For the toggle button, this means that
> brightness control becomes on/off. In addition, in the absence of a
> DE, the keyboard brightness does not work.
> 
> Therefore, expose an event handler for the keyboard brightness control
> which can then be used by hid-asus.
> 
> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
> ---
>   drivers/platform/x86/asus-wmi.c            | 39 ++++++++++++++++++++++
>   include/linux/platform_data/x86/asus-wmi.h | 11 ++++++
>   2 files changed, 50 insertions(+)
> 
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 95ef9b1d321bb..5ebe141294ecf 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -1536,6 +1536,45 @@ void asus_hid_unregister_listener(struct asus_hid_listener *bdev)
>   }
>   EXPORT_SYMBOL_GPL(asus_hid_unregister_listener);
>   
> +static void do_kbd_led_set(struct led_classdev *led_cdev, int value);
> +
> +int asus_hid_event(enum asus_hid_event event)
> +{
> +	unsigned long flags;
> +	int brightness;
> +
> +	spin_lock_irqsave(&asus_ref.lock, flags);
> +	if (!asus_ref.asus || !asus_ref.asus->kbd_led_registered) {
> +		spin_unlock_irqrestore(&asus_ref.lock, flags);
> +		return -EBUSY;
> +	}
> +	brightness = asus_ref.asus->kbd_led_wk;
> +
> +	switch (event) {
> +	case ASUS_EV_BRTUP:
> +		brightness += 1;
> +		break;
> +	case ASUS_EV_BRTDOWN:
> +		brightness -= 1;
> +		break;
> +	case ASUS_EV_BRTTOGGLE:
> +		if (brightness >= 3)
> +			brightness = 0;
> +		else
> +			brightness += 1;
> +		break;
> +	}
> +
> +	do_kbd_led_set(&asus_ref.asus->kbd_led, brightness);
> +	led_classdev_notify_brightness_hw_changed(&asus_ref.asus->kbd_led,
> +						  asus_ref.asus->kbd_led_wk);
> +
> +	spin_unlock_irqrestore(&asus_ref.lock, flags);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(asus_hid_event);
> +
>   /*
>    * These functions actually update the LED's, and are called from a
>    * workqueue. By doing this as separate work rather than when the LED
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index c513b5a732323..9adbe8abef090 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -162,11 +162,18 @@ struct asus_hid_listener {
>   	void (*brightness_set)(struct asus_hid_listener *listener, int brightness);
>   };
>   
> +enum asus_hid_event {
> +	ASUS_EV_BRTUP,
> +	ASUS_EV_BRTDOWN,
> +	ASUS_EV_BRTTOGGLE,
> +};
> +
>   #if IS_REACHABLE(CONFIG_ASUS_WMI)
>   int asus_wmi_evaluate_method(u32 method_id, u32 arg0, u32 arg1, u32 *retval);
>   
>   int asus_hid_register_listener(struct asus_hid_listener *cdev);
>   void asus_hid_unregister_listener(struct asus_hid_listener *cdev);
> +int asus_hid_event(enum asus_hid_event event);
>   #else
>   static inline int asus_wmi_evaluate_method(u32 method_id, u32 arg0, u32 arg1,
>   					   u32 *retval)
> @@ -181,6 +188,10 @@ static inline int asus_hid_register_listener(struct asus_hid_listener *bdev)
>   static inline void asus_hid_unregister_listener(struct asus_hid_listener *bdev)
>   {
>   }
> +static inline int asus_hid_event(enum asus_hid_event event)
> +{
> +	return -ENODEV;
> +}
>   #endif
>   
>   #endif	/* __PLATFORM_DATA_X86_ASUS_WMI_H */


Reviewed-by: Luke D. Jones <luke@ljones.dev>
Tested-by: Luke D. Jones <luke@ljones.dev>