[U-Boot] [PATCH 1/2] mmc: sunxi: Support cd-inverted DT property

[Maxime Ripard <maxime.ripard@free-electrons.com>]

On Mon, Dec 18, 2017 at 10:09:41PM +0200, Tuomas Tynkkynen wrote:
> Commit 8620f384098b ("dm: sunxi: Linksprite_pcDuino3: Correct polarity
> of MMC card detect") claims that the Pcduino3 device tree has an
> incorrect polarity for the card detect pin, but the actual problem is
> that unlike the Linux MMC driver, the U-Boot driver isn't respecting the
> cd-invert property (see Documentation/devicetree/bindings/mmc/mmc.txt)
> which tells that the card detect signal level should be inverted.
> 
> Fix this properly by adding support for the cd-inverted property while
> reverting the original commit at the same time. While at it, I noticed
> the driver always enables pullups for the card detect line, which is not
> right if the card detect GPIO is active-high, so fix that as well.
> 
> Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
> ---
>  arch/arm/dts/sun7i-a20-pcduino3.dts |  2 +-
>  drivers/mmc/sunxi_mmc.c             | 12 ++++++++++--
>  2 files changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/dts/sun7i-a20-pcduino3.dts b/arch/arm/dts/sun7i-a20-pcduino3.dts
> index 37b1e0ee9b..1a8b39be1d 100644
> --- a/arch/arm/dts/sun7i-a20-pcduino3.dts
> +++ b/arch/arm/dts/sun7i-a20-pcduino3.dts
> @@ -164,7 +164,7 @@
>  	pinctrl-0 = <&mmc0_pins_a>, <&mmc0_cd_pin_reference_design>;
>  	vmmc-supply = <&reg_vcc3v3>;
>  	bus-width = <4>;
> -	cd-gpios = <&pio 7 1 GPIO_ACTIVE_LOW>; /* PH1 */
> +	cd-gpios = <&pio 7 1 GPIO_ACTIVE_HIGH>; /* PH1 */
>  	cd-inverted;
>  	status = "okay";
>  };
> diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
> index 4edb4be46c..7cc7303570 100644
> --- a/drivers/mmc/sunxi_mmc.c
> +++ b/drivers/mmc/sunxi_mmc.c
> @@ -30,6 +30,7 @@ struct sunxi_mmc_priv {
>  	uint32_t *mclkreg;
>  	unsigned fatal_err;
>  	struct gpio_desc cd_gpio;	/* Change Detect GPIO */
> +	int cd_inverted;
>  	struct sunxi_mmc *reg;
>  	struct mmc_config cfg;
>  };
> @@ -545,7 +546,7 @@ static int sunxi_mmc_getcd(struct udevice *dev)
>  	struct sunxi_mmc_priv *priv = dev_get_priv(dev);
>  
>  	if (dm_gpio_is_valid(&priv->cd_gpio))
> -		return dm_gpio_get_value(&priv->cd_gpio);
> +		return dm_gpio_get_value(&priv->cd_gpio) ^ priv->cd_inverted;
>  
>  	return 1;
>  }
> @@ -606,8 +607,15 @@ static int sunxi_mmc_probe(struct udevice *dev)
>  	if (!gpio_request_by_name(dev, "cd-gpios", 0, &priv->cd_gpio,
>  				  GPIOD_IS_IN)) {
>  		int cd_pin = gpio_get_number(&priv->cd_gpio);
> +		int cd_state = priv->cd_gpio.flags & GPIOD_ACTIVE_LOW ? 0 : 1;

Isn't that change itself enough to get what you wanted?

You really shouldn't be doing anything else.

Maxime

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