Re: [PATCH v5 2/2] staging: iio: ad2s1210: Add device tree support.

[Slawomir Stepien]

Hi

On paÅ 26, 2018 18:55, Nishad Kamdar wrote:
> Add device tree table for matching vendor ID
> and support for retrieving platform data
> from device tree.

So maybe you should make 2 commits?

> Signed-off-by: Nishad Kamdar <nishadkamdar@xxxxxxxxx>
> ---
>  drivers/staging/iio/resolver/ad2s1210.c | 43 ++++++++++++++++++++++++-
>  1 file changed, 42 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index 93c3c70ce62e..9fd5461c4ed0 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -17,6 +17,7 @@
>  #include <linux/delay.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  
>  #include <linux/iio/iio.h>
>  #include <linux/iio/sysfs.h>
> @@ -669,6 +670,27 @@ static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_OF
> +static struct ad2s1210_platform_data *ad2s1210_parse_dt(struct device *dev)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct ad2s1210_platform_data *pdata;
> +
> +	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		return NULL;
> +
> +	pdata->gpioin = of_property_read_bool(np, "adi,gpioin");

Why here you are adding "adi", but you are not adding it to the gpios in prev
commit?

I've also seen this: https://patchwork.kernel.org/patch/10355839/. However I do
not understand why adding vendor id to props is needed...

> +
> +	return pdata;
> +}
> +#else
> +static struct ad2s1210_platform_data *ad2s1210_parse_dt(struct device *dev)
> +{
> +	return NULL;
> +}
> +#endif
> +
>  static int ad2s1210_probe(struct spi_device *spi)
>  {
>  	struct iio_dev *indio_dev;
> @@ -682,7 +704,19 @@ static int ad2s1210_probe(struct spi_device *spi)
>  	if (!indio_dev)
>  		return -ENOMEM;
>  	st = iio_priv(indio_dev);
> -	st->pdata = spi->dev.platform_data;
> +	if (spi->dev.of_node) {
> +		st->pdata = ad2s1210_parse_dt(&spi->dev);
> +		if (!st->pdata)
> +			return -EINVAL;
> +	} else {
> +		st->pdata = spi->dev.platform_data;
> +	}
> +
> +	if (!st->pdata) {
> +		dev_err(&spi->dev, "ad2s1210: no platform data supplied\n");
> +		return -EINVAL;
> +	}
> +

Why not just use only device-tree here? The ad2s1210_platform_data has now only
one entry... In that case remember to add "depends on OF" in Kconfig.

>  	ret = ad2s1210_setup_gpios(st);
>  	if (ret < 0)
>  		return ret;
> @@ -724,6 +758,12 @@ static int ad2s1210_remove(struct spi_device *spi)
>  	return 0;
>  }
>  
> +static const struct of_device_id ad2s1210_of_match[] = {
> +	{ .compatible = "adi,ad2s1210", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, ad2s1210_of_match);
> +
>  static const struct spi_device_id ad2s1210_id[] = {
>  	{ "ad2s1210" },
>  	{}
> @@ -733,6 +773,7 @@ MODULE_DEVICE_TABLE(spi, ad2s1210_id);
>  static struct spi_driver ad2s1210_driver = {
>  	.driver = {
>  		.name = DRV_NAME,
> +		.of_match_table = of_match_ptr(ad2s1210_of_match),
>  	},
>  	.probe = ad2s1210_probe,
>  	.remove = ad2s1210_remove,

-- 
Slawomir Stepien