Re: [PATCH 1/4] devfreq: exynos4: Support devicetree to get device id of Exynos4 SoC

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

Hi Chanwoo,

On Wednesday, March 12, 2014 08:47:59 PM Chanwoo Choi wrote:
> This patch support DT(DeviceTree) method to probe exynos4_bus and get device
> id of each Exynos4 SoC by using dt helper function.
> 
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
>  drivers/devfreq/exynos/exynos4_bus.c | 26 +++++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/devfreq/exynos/exynos4_bus.c b/drivers/devfreq/exynos/exynos4_bus.c
> index e07b0c6..168a7c6 100644
> --- a/drivers/devfreq/exynos/exynos4_bus.c
> +++ b/drivers/devfreq/exynos/exynos4_bus.c
> @@ -23,6 +23,7 @@
>  #include <linux/devfreq.h>
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/of.h>
>  #include <linux/module.h>
>  
>  /* Exynos4 ASV has been in the mailing list, but not upstreamed, yet. */
> @@ -1017,6 +1018,28 @@ unlock:
>  	return NOTIFY_DONE;
>  }
>  
> +static struct of_device_id exynos4_busfreq_id_match[] = {
> +	{
> +		.compatible = "samsung,exynos4210-busfreq",
> +		.data = (void *)TYPE_BUSF_EXYNOS4210,
> +	}, {
> +		.compatible = "samsung,exynos4x12-busfreq",
> +		.data = (void *)TYPE_BUSF_EXYNOS4x12,
> +	},
> +};
> +
> +static int exynos4_busfreq_get_driver_data(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	const struct of_device_id *match;
> +
> +	match = of_match_node(exynos4_busfreq_id_match, dev->of_node);
> +	if (!match)
> +		return -ENODEV;
> +
> +	return (int) match->data;
> +}
> +
>  static int exynos4_busfreq_probe(struct platform_device *pdev)
>  {
>  	struct busfreq_data *data;
> @@ -1030,7 +1053,7 @@ static int exynos4_busfreq_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	}
>  
> -	data->type = pdev->id_entry->driver_data;
> +	data->type = exynos4_busfreq_get_driver_data(pdev);
>  	data->dmc[0].hw_base = S5P_VA_DMC0;
>  	data->dmc[1].hw_base = S5P_VA_DMC1;
>  	data->pm_notifier.notifier_call = exynos4_busfreq_pm_notifier_event;
> @@ -1135,6 +1158,7 @@ static struct platform_driver exynos4_busfreq_driver = {
>  		.name	= "exynos4-busfreq",
>  		.owner	= THIS_MODULE,
>  		.pm	= &exynos4_busfreq_pm,
> +		.of_match_table = exynos4_busfreq_id_match,
>  	},
>  };

It looks OK but it would be good to also add bindings documentation file,
i.e. Documentation/devicetree/bindings/devfreq/exynos4_bus.txt.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics