Re: [PATCH] input: gpio-keys: initialize the input value with the current gpioval

["Sascha Hauer" <s.hauer@pengutronix.de>]

Hi Marco,

I just sent an alternative patch which avoids some code duplication.
It's untested, maybe you could spin a test for your case.

Sascha

On 2026-06-25 13:51, Marco Felsch wrote:
> This is required for deep-probe systems which prove the "gpio-keys"
> device on demand. In such case the input value is not yet accessible
> once the probe finished. However, board code queries the input device
> value directly after the of.*ensure.*probed().
> 
> Therefore provide a sane default by reading the gpio value during probe
> and init the input device value.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/input/gpio_keys.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/input/gpio_keys.c b/drivers/input/gpio_keys.c
> index b52738f5ccb2..316ed73ddfd1 100644
> --- a/drivers/input/gpio_keys.c
> +++ b/drivers/input/gpio_keys.c
> @@ -143,6 +143,26 @@ static int gpio_keys_probe_dt(struct gpio_keys *gk, struct device *dev)
>  	return 0;
>  }
>  
> +static int gpio_keys_set_initialval(struct gpio_keys *gk)
> +{
> +	struct gpio_key *gb;
> +	int i, pressed;
> +
> +	for (i = 0; i < gk->nbuttons; i++) {
> +
> +		gb = &gk->buttons[i];
> +		pressed = gpiod_get_value(gb->gpio);
> +
> +		if (pressed != gb->previous_state) {
> +			gb->debounce_start = get_time_ns();
> +			input_report_key_event(&gk->input, gb->code, pressed);
> +			dev_dbg(gk->input.parent, "%s gpio #%d as %d\n",
> +				pressed ? "pressed" : "released", i, gb->code);
> +			gb->previous_state = pressed;
> +		}
> +	}
> +}
> +
>  static int __init gpio_keys_probe(struct device *dev)
>  {
>  	int ret;
> @@ -163,6 +183,8 @@ static int __init gpio_keys_probe(struct device *dev)
>  	if (ret)
>  		return ret;
>  
> +	gpio_keys_set_initialval(gk);
> +
>  	ret = poller_async_register(&gk->poller, dev_name(dev));
>  	if (ret)
>  		return ret;
> -- 
> 2.47.3
> 
> 
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |