Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1329119 > unrolled thread

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

Back to article view | Back to linux.kernel

Contents

  [PATCH] pinctrl: sunxi: set pin function as input on export Krzysztof Adamski <krzysztof.adamski@tieto.com> - 2016-02-08 15:40 +0100
    Re: [PATCH] pinctrl: sunxi: set pin function as input on export Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-02-08 18:30 +0100

#1329119 — [PATCH] pinctrl: sunxi: set pin function as input on export

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@tieto.com>
---
 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

[toc] | [next] | [standalone]

#1329377

[Multipart message — attachments visible in raw view] — view raw

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@tieto.com>
> ---
>  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

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web