Re: [PATCH v3] gpio: omap: handle pin config bias flags

["Gustavo A. R. Silva" <gustavo@embeddedor.com>]

Hi Drew,

Somehow I ran into this patch in Linus' tree:

https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/commit/?h=for-next&id=75dec56710dfafd37daa95e756c5d1840932ba90

Please, see some comments below...

On 7/17/20 14:40, Drew Fustini wrote:
> Modify omap_gpio_set_config() to handle pin config bias flags by calling
> gpiochip_generic_config().
> 
> The pin group for the gpio line must have the corresponding pinconf
> properties:
> 
> PIN_CONFIG_BIAS_PULL_UP requires "pinctrl-single,bias-pullup"
> PIN_CONFIG_BIAS_PULL_DOWN requires "pinctrl-single,bias-pulldown"
> 
> This is necessary for pcs_pinconf_set() to find the requested bias
> parameter in the PIN_MAP_TYPE_CONFIGS_GROUP pinctrl map.
> 
> Signed-off-by: Drew Fustini <drew@beagleboard.org>
> Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
> Acked-by: Tony Lindgren <tony@atomide.com>
> Link: https://lore.kernel.org/r/20200715213738.1640030-1-drew@beagleboard.org
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/gpio/gpio-omap.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> v3 changes:
> - adjust the braces to match the correct coding style
> - note: I originally re-submitted this as v2 by accident when it should
>   have been v3. Sorry for the noise.
> 
> v2 changes:
> - simplify handling of -ENOTSUPP return value per Grygorii's suggestion
> 
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index b8e2ecc3eade..0ccb31de0b67 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -896,12 +896,18 @@ static int omap_gpio_set_config(struct gpio_chip *chip, unsigned offset,
>  				unsigned long config)
>  {
>  	u32 debounce;
> +	int ret = -ENOTSUPP;
> +
> +	if ((pinconf_to_config_param(config) == PIN_CONFIG_BIAS_DISABLE) ||
> +	    (pinconf_to_config_param(config) == PIN_CONFIG_BIAS_PULL_UP) ||
> +	    (pinconf_to_config_param(config) == PIN_CONFIG_BIAS_PULL_DOWN)) {
> +		ret = gpiochip_generic_config(chip, offset, config);
> +	} else if (pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE) {
> +		debounce = pinconf_to_config_argument(config);
> +		ret = omap_gpio_debounce(chip, offset, debounce);
> +	}
>  
> -	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
> -		return -ENOTSUPP;
> -
> -	debounce = pinconf_to_config_argument(config);
> -	return omap_gpio_debounce(chip, offset, debounce);
> +	return ret;
>  }
>  
>  static void omap_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> 

Maybe next time you could consider coding something like this, instead:

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 8dd86b9fae53..7fbe0c9e1fc1 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -899,16 +899,18 @@ static int omap_gpio_set_config(struct gpio_chip *chip, unsigned offset,
        u32 debounce;
        int ret = -ENOTSUPP;

-       if ((pinconf_to_config_param(config) == PIN_CONFIG_BIAS_DISABLE) ||
-           (pinconf_to_config_param(config) == PIN_CONFIG_BIAS_PULL_UP) ||
-           (pinconf_to_config_param(config) == PIN_CONFIG_BIAS_PULL_DOWN))
-       {
+       switch (pinconf_to_config_param(config)) {
+       case PIN_CONFIG_BIAS_DISABLE:
+       case PIN_CONFIG_BIAS_PULL_UP:
+       case PIN_CONFIG_BIAS_PULL_DOWN:
                ret = gpiochip_generic_config(chip, offset, config);
-       }
-       else if (pinconf_to_config_param(config) == PIN_CONFIG_INPUT_DEBOUNCE)
-       {
+               break;
+       case PIN_CONFIG_INPUT_DEBOUNCE:
                debounce = pinconf_to_config_argument(config);
                ret = omap_gpio_debounce(chip, offset, debounce);
+               break;
+       default:
+               break;
        }

        return ret;

It looks a bit more readable and cleaner. :)

Thanks
--
Gustavo