Re: [PATCH v4 07/11] platform/x86: asus-wmi: add keyboard brightness event handler

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

On Mon, 24 Mar 2025, 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.
> 
> Reviewed-by: Luke D. Jones <luke@ljones.dev>
> Tested-by: Luke D. Jones <luke@ljones.dev>
> 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 ff1d7ccb3982f..27468d67dba09 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)

Add ASUS_EV_MAX_BRIGHTNESS instead of a literal?

> +			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 */
> 

-- 
 i.