Re: [PATCH] gpio: langwell: ensure alternate function is cleared

[Grant Likely]

On Mon, Oct 03, 2011 at 02:36:07PM +0300, Adrian Hunter wrote:
> Alternate function must be zero for the pin to act as
> a GPIO.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>

Applied, thanks.

g.

> ---
>  drivers/gpio/gpio-langwell.c |   27 +++++++++++++++++++++++++++
>  1 files changed, 27 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpio/gpio-langwell.c b/drivers/gpio/gpio-langwell.c
> index d2eb57c..00692e8 100644
> --- a/drivers/gpio/gpio-langwell.c
> +++ b/drivers/gpio/gpio-langwell.c
> @@ -59,6 +59,7 @@ enum GPIO_REG {
>  	GRER,		/* rising edge detect */
>  	GFER,		/* falling edge detect */
>  	GEDR,		/* edge detect result */
> +	GAFR,		/* alt function */
>  };
>  
>  struct lnw_gpio {
> @@ -81,6 +82,31 @@ static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned offset,
>  	return ptr;
>  }
>  
> +static void __iomem *gpio_reg_2bit(struct gpio_chip *chip, unsigned offset,
> +				   enum GPIO_REG reg_type)
> +{
> +	struct lnw_gpio *lnw = container_of(chip, struct lnw_gpio, chip);
> +	unsigned nreg = chip->ngpio / 32;
> +	u8 reg = offset / 16;
> +	void __iomem *ptr;
> +
> +	ptr = (void __iomem *)(lnw->reg_base + reg_type * nreg * 4 + reg * 4);
> +	return ptr;
> +}
> +
> +static int lnw_gpio_request(struct gpio_chip *chip, unsigned offset)
> +{
> +	void __iomem *gafr = gpio_reg_2bit(chip, offset, GAFR);
> +	u32 value = readl(gafr);
> +	int shift = (offset % 16) << 1, af = (value >> shift) & 3;
> +
> +	if (af) {
> +		value &= ~(3 << shift);
> +		writel(value, gafr);
> +	}
> +	return 0;
> +}
> +
>  static int lnw_gpio_get(struct gpio_chip *chip, unsigned offset)
>  {
>  	void __iomem *gplr = gpio_reg(chip, offset, GPLR);
> @@ -321,6 +347,7 @@ static int __devinit lnw_gpio_probe(struct pci_dev *pdev,
>  	lnw->reg_base = base;
>  	lnw->irq_base = irq_base;
>  	lnw->chip.label = dev_name(&pdev->dev);
> +	lnw->chip.request = lnw_gpio_request;
>  	lnw->chip.direction_input = lnw_gpio_direction_input;
>  	lnw->chip.direction_output = lnw_gpio_direction_output;
>  	lnw->chip.get = lnw_gpio_get;
> -- 
> 1.7.6
> 
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