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@xxxxxxxxx>
> ---
> 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
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