RE: [PATCH] iio: resolver: ad2s1210: add reset gpio support

[Hennerich, Michael]

> -----Original Message-----
> From: David Lechner <dlechner@xxxxxxxxxxxx>
> Sent: Montag, 16. Oktober 2023 17:43
> To: linux-iio@xxxxxxxxxxxxxxx
> Cc: David Lechner <dlechner@xxxxxxxxxxxx>; Jonathan Cameron
> <jic23@xxxxxxxxxx>; Hennerich, Michael <Michael.Hennerich@xxxxxxxxxx>;
> Sa, Nuno <Nuno.Sa@xxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] iio: resolver: ad2s1210: add reset gpio support
> 
> 
> This adds support for the optional reset gpio to the ad2s1210 resolver driver. If
> the gpio is present in the device tree, it is toggled during driver probe before the
> reset of the device initialization. As per the devicetree bindings, it is expected for
> the gpio to configured as active low.
> 
> Suggested-by: Michael Hennerich <Michael.Hennerich@xxxxxxxxxx>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
> ---

Acked-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>

>  drivers/iio/resolver/ad2s1210.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/iio/resolver/ad2s1210.c b/drivers/iio/resolver/ad2s1210.c
> index 8646389ec88d..a414eef12e5e 100644
> --- a/drivers/iio/resolver/ad2s1210.c
> +++ b/drivers/iio/resolver/ad2s1210.c
> @@ -1426,6 +1426,7 @@ static int ad2s1210_setup_gpios(struct
> ad2s1210_state *st)  {
>  	struct device *dev = &st->sdev->dev;
>  	struct gpio_descs *resolution_gpios;
> +	struct gpio_desc *reset_gpio;
>  	DECLARE_BITMAP(bitmap, 2);
>  	int ret;
> 
> @@ -1481,6 +1482,17 @@ static int ad2s1210_setup_gpios(struct
> ad2s1210_state *st)
>  					     "failed to set resolution gpios\n");
>  	}
> 
> +	/* If the optional reset GPIO is present, toggle it to do a hard reset. */
> +	reset_gpio = devm_gpiod_get_optional(dev, "reset",
> GPIOD_OUT_HIGH);
> +	if (IS_ERR(reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(reset_gpio),
> +				     "failed to request reset GPIO\n");
> +
> +	if (reset_gpio) {
> +		udelay(10);
> +		gpiod_set_value(reset_gpio, 0);
> +	}
> +
>  	return 0;
>  }
> 
> --
> 2.42.0