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

From: Slawomir Stepien
Date: Sat Oct 27 2018 - 11:58:58 EST


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