Re: [PATCH v2] pinctrl: baytrail: show output gpio state correctly on Intel Baytrail

From: Felipe Balbi
Date: Tue Oct 14 2014 - 14:19:30 EST


On Tue, Oct 14, 2014 at 10:54:37AM -0700, David Cohen wrote:
> Even if a gpio pin is set to output, we still need to set INPUT_EN
> functionality (by clearing INPUT_EN bit) to be able to read the pin's
> level.
>
> E.g. without this change, we'll always read low level state from sysfs.
>
> Cc: <stable@xxxxxxxxxxxxxxx> # v3.14+
> Cc: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>

Reviewed-by: Felipe Balbi <balbi@xxxxxx>

> ---
>
> v1 to v2: improved patch's body description as requested by Felipe Balbi
> ---
>
> drivers/pinctrl/pinctrl-baytrail.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c
> index e12e5b07f6d7..c23d8ded936d 100644
> --- a/drivers/pinctrl/pinctrl-baytrail.c
> +++ b/drivers/pinctrl/pinctrl-baytrail.c
> @@ -318,7 +318,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip,
> "Potential Error: Setting GPIO with direct_irq_en to output");
>
> reg_val = readl(reg) | BYT_DIR_MASK;
> - reg_val &= ~BYT_OUTPUT_EN;
> + reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN);
>
> if (value)
> writel(reg_val | BYT_LEVEL, reg);
> --
> 2.1.0
>

--
balbi

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