Re: [PATCH v3 1/2] Input: Add a Kconfig to emulate KEY_SCREENLOCK with META + L

[Hans de Goede <hdegoede@redhat.com>]

Hi Mario,

On 17-Apr-25 3:37 AM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> In the PC industry KEY_SCREENLOCK isn't used as frequently as it used
> to be. Modern versions of Windows [1], GNOME and KDE support "META" + "L"
> to lock the screen. Modern hardware [2] also sends this sequence of
> events for keys with a silkscreen for screen lock.
> 
> Introduced a new Kconfig option that will change KEY_SCREENLOCK when
> emitted by driver to META + L.
> 
> Link: https://support.microsoft.com/en-us/windows/keyboard-shortcuts-in-windows-dcc61a57-8ff0-cffe-9796-cb9706c75eec [1]
> Link: https://www.logitech.com/en-us/shop/p/k860-split-ergonomic.920-009166 [2]
> Suggested-by: Armin Wolf <W_Armin@gmx.de>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v3:
>  * Emulation in the input core instead
> 
>  drivers/input/Kconfig |  8 ++++++++
>  drivers/input/input.c | 19 +++++++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/drivers/input/Kconfig b/drivers/input/Kconfig
> index 88ecdf5218ee9..ffb4163fe315f 100644
> --- a/drivers/input/Kconfig
> +++ b/drivers/input/Kconfig
> @@ -174,6 +174,14 @@ config INPUT_APMPOWER
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called apm-power.
>  
> +config INPUT_SCREENLOCK_EMULATION
> +	bool "Pass KEY_SCREENLOCK as META + L"
> +	help
> +	  Say Y here if you want KEY_SCREENLOCK to be passed to userspace as
> +	  META + L.
> +
> +	  If unsure, say Y.
> +
>  comment "Input Device Drivers"
>  
>  source "drivers/input/keyboard/Kconfig"
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index dfeace85c4710..08a857cea0c5d 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -370,6 +370,13 @@ void input_handle_event(struct input_dev *dev,
>  	}
>  }
>  
> +static void handle_screenlock_as_meta_l(struct input_dev *dev, unsigned int type,
> +					int value)
> +{
> +	input_handle_event(dev, type, KEY_LEFTMETA, value);
> +	input_handle_event(dev, type, KEY_L, value);
> +}
> +
>  /**
>   * input_event() - report new input event
>   * @dev: device that generated the event
> @@ -392,6 +399,12 @@ void input_event(struct input_dev *dev,
>  {
>  	if (is_event_supported(type, dev->evbit, EV_MAX)) {
>  		guard(spinlock_irqsave)(&dev->event_lock);
> +#ifdef CONFIG_INPUT_SCREENLOCK_EMULATION
> +		if (code == KEY_SCREENLOCK) {
> +			handle_screenlock_as_meta_l(dev, type, value);
> +			return;
> +		}
> +#endif
>  		input_handle_event(dev, type, code, value);
>  	}
>  }
> @@ -2134,6 +2147,12 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
>  
>  	switch (type) {
>  	case EV_KEY:
> +#ifdef CONFIG_INPUT_SCREENLOCK_EMULATION
> +		if (code == KEY_SCREENLOCK) {
> +			__set_bit(KEY_L, dev->keybit);
> +			__set_bit(KEY_LEFTMETA, dev->keybit);
> +		}

Shouldn't there be a "break;" inside the if?

Since KEY_SCREENLOCK events will never get reported when
CONFIG_INPUT_SCREENLOCK_EMULATION is set, I think it would
be netter to not set it in dev->keybit ?

Regards,

Hans




> +#endif
>  		__set_bit(code, dev->keybit);
>  		break;
>