Re: [PATCH] pinctrl: sunxi: set pin function as input on export

[Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>]

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Hi,

On Mon, Feb 08, 2016 at 03:37:22PM +0100, Krzysztof Adamski wrote:
> Default function of a pin in sunxi SoCs is "disabled". By default gpios
> exported by sysfs are set as input and indeed, when reading "direction"
> file you will get "in". The "value" pin won't return proper value,
> though, confusing user of this interface.
> 
> This patch sets direction of a GPIO as input when exporting it.
> 
> Signed-off-by: Krzysztof Adamski <krzysztof.adamski-++hxYGjEMp0AvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/pinctrl/sunxi/pinctrl-sunxi.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> index 7a2465f..905a9fb 100644
> --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
> @@ -452,6 +452,16 @@ static int sunxi_pinctrl_gpio_direction_input(struct gpio_chip *chip,
>  	return pinctrl_gpio_direction_input(chip->base + offset);
>  }
>  
> +int sunxi_pinctrl_gpio_request(struct gpio_chip *chip, unsigned offset)
> +{
> +	int ret = pinctrl_gpio_direction_input(chip->base + offset);
> +
> +	if (ret)
> +		return ret;
> +
> +	return pinctrl_request_gpio(chip->base + offset);
> +}
> +
>  static int sunxi_pinctrl_gpio_get(struct gpio_chip *chip, unsigned offset)
>  {
>  	struct sunxi_pinctrl *pctl = gpiochip_get_data(chip);
> @@ -946,7 +956,7 @@ int sunxi_pinctrl_init(struct platform_device *pdev,
>  
>  	last_pin = pctl->desc->pins[pctl->desc->npins - 1].pin.number;
>  	pctl->chip->owner = THIS_MODULE;
> -	pctl->chip->request = gpiochip_generic_request,
> +	pctl->chip->request = sunxi_pinctrl_gpio_request,
>  	pctl->chip->free = gpiochip_generic_free,
>  	pctl->chip->direction_input = sunxi_pinctrl_gpio_direction_input,
>  	pctl->chip->direction_output = sunxi_pinctrl_gpio_direction_output,
> -- 
> 2.4.2
> 

It seems to me that it's something that should be enforced in the
core, there's nothing sunxi specific here.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com