Re: [PATCH 1/4] iio: adc: rockchip_saradc: reset saradc controller before programming it

[John Keeping]

On Tue, 26 Jul 2016 14:11:47 +0800, Caesar Wang wrote:

> SARADC controller needs to be reset before programming it, otherwise
> it will not function properly.
> 
> Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
> Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
> Cc: Heiko Stuebner <heiko@xxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: linux-iio@xxxxxxxxxxxxxxx
> Cc: linux-rockchip@xxxxxxxxxxxxxxxxxxx
> ---
> 
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index f9ad6c2..2f0e110 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c
> @@ -218,6 +231,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
>  	if (IS_ERR(info->regs))
>  		return PTR_ERR(info->regs);
>  
> +	info->reset = devm_reset_control_get(&pdev->dev, "saradc-apb");
> +	if (IS_ERR(info->reset)) {
> +		ret = PTR_ERR(info->reset);
> +		dev_err(&pdev->dev, "failed to get saradc reset: %d\n", ret);
> +		return ret;
> +	}

Does this need to handle ENOENT so as to avoid failing with old device
tree blobs?