Re: [PATCH v3] iio: dac: ad5755: make use of of_device_id table

[Jonathan Cameron]

On Sat, 13 Apr 2024 17:45:11 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:

> Store pointers to chip info (struct ad5755_chip_info) in driver match
> data, instead of enum, so every value will be != 0, populate the
> of_device_id table and use it in driver.  Even though it is one change,
> it gives multiple benefits:
> 1. Allows to use spi_get_device_match_data() dropping local 'type'
>    variable.
> 2. Makes both ID tables usable, so kernel can match via any of these
>    methods.
> 3. Code is more obvious as both tables are properly filled.
> 4. Fixes W=1 warning:
>    ad5755.c:866:34: error: unused variable 'ad5755_of_match' [-Werror,-Wunused-const-variable]
> 
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
> 
Applied but only pushed out as testing for 0-day so far, so I can rebase
to add tags (or pull it if anyone finds an issue!)

Thanks for doing this Krzysztof.

Jonathan

> ---
> 
> Changes in v3:
> 1. Use pointers, according to Jonathan comments.
> 
> v2: https://lore.kernel.org/all/20240226192555.14aa178e@jic23-huawei/
> 
> An old v1:
> https://lore.kernel.org/all/20230810111933.205619-1-krzysztof.kozlowski@xxxxxxxxxx/
> ---
>  drivers/iio/dac/ad5755.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
> index 404865e35460..0b24cb19ac9d 100644
> --- a/drivers/iio/dac/ad5755.c
> +++ b/drivers/iio/dac/ad5755.c
> @@ -809,7 +809,6 @@ static struct ad5755_platform_data *ad5755_parse_fw(struct device *dev)
>  
>  static int ad5755_probe(struct spi_device *spi)
>  {
> -	enum ad5755_type type = spi_get_device_id(spi)->driver_data;
>  	const struct ad5755_platform_data *pdata;
>  	struct iio_dev *indio_dev;
>  	struct ad5755_state *st;
> @@ -824,7 +823,7 @@ static int ad5755_probe(struct spi_device *spi)
>  	st = iio_priv(indio_dev);
>  	spi_set_drvdata(spi, indio_dev);
>  
> -	st->chip_info = &ad5755_chip_info_tbl[type];
> +	st->chip_info = spi_get_device_match_data(spi);
>  	st->spi = spi;
>  	st->pwr_down = 0xf;
>  
> @@ -854,21 +853,21 @@ static int ad5755_probe(struct spi_device *spi)
>  }
>  
>  static const struct spi_device_id ad5755_id[] = {
> -	{ "ad5755", ID_AD5755 },
> -	{ "ad5755-1", ID_AD5755 },
> -	{ "ad5757", ID_AD5757 },
> -	{ "ad5735", ID_AD5735 },
> -	{ "ad5737", ID_AD5737 },
> +	{ "ad5755", (kernel_ulong_t)&ad5755_chip_info_tbl[ID_AD5755] },
> +	{ "ad5755-1", (kernel_ulong_t)&ad5755_chip_info_tbl[ID_AD5755] },
> +	{ "ad5757", (kernel_ulong_t)&ad5755_chip_info_tbl[ID_AD5757] },
> +	{ "ad5735", (kernel_ulong_t)&ad5755_chip_info_tbl[ID_AD5735] },
> +	{ "ad5737", (kernel_ulong_t)&ad5755_chip_info_tbl[ID_AD5737] },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(spi, ad5755_id);
>  
>  static const struct of_device_id ad5755_of_match[] = {
> -	{ .compatible = "adi,ad5755" },
> -	{ .compatible = "adi,ad5755-1" },
> -	{ .compatible = "adi,ad5757" },
> -	{ .compatible = "adi,ad5735" },
> -	{ .compatible = "adi,ad5737" },
> +	{ .compatible = "adi,ad5755", &ad5755_chip_info_tbl[ID_AD5755] },
> +	{ .compatible = "adi,ad5755-1", &ad5755_chip_info_tbl[ID_AD5755] },
> +	{ .compatible = "adi,ad5757", &ad5755_chip_info_tbl[ID_AD5757] },
> +	{ .compatible = "adi,ad5735", &ad5755_chip_info_tbl[ID_AD5735] },
> +	{ .compatible = "adi,ad5737", &ad5755_chip_info_tbl[ID_AD5737] },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(of, ad5755_of_match);
> @@ -876,6 +875,7 @@ MODULE_DEVICE_TABLE(of, ad5755_of_match);
>  static struct spi_driver ad5755_driver = {
>  	.driver = {
>  		.name = "ad5755",
> +		.of_match_table = ad5755_of_match,
>  	},
>  	.probe = ad5755_probe,
>  	.id_table = ad5755_id,