[PATCH 3/4] ALSA: sound/atmel/ac97c.c: Add device tree support

[Alexandre Belloni]

On 12/04/2014 at 11:08:26 +0200, Alexander Stein wrote :

Even if dead simple, please try to include a commit log.

> Signed-off-by: Alexander Stein <alexanders83 at web.de>
> ---
>  .../devicetree/bindings/sound/atmel_ac97c.txt      | 20 +++++++++
>  sound/atmel/ac97c.c                                | 52 ++++++++++++++++++++--

You should separate the documentation from the rest of the patch. The
patch adding documentation is actually the only one of the series that
should go to devicetree at vger.kernel.org and the devicetree maintainers.

>  2 files changed, 69 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/sound/atmel_ac97c.txt
> 
> diff --git a/Documentation/devicetree/bindings/sound/atmel_ac97c.txt b/Documentation/devicetree/bindings/sound/atmel_ac97c.txt
> new file mode 100644
> index 0000000..9839403
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/sound/atmel_ac97c.txt
> @@ -0,0 +1,20 @@
> +* Atmel AC97 controller
> +
> +Required properties:
> +  - compatible: "atmel,atmel_ac97c"
> +  - reg: Address and length of the register set for the device
> +  - interrupts: Should contain AC97 interrupt
> +  - atmel,reset-pin: GPIO for resetting the codec
> +Optional properties:
> +  - pinctrl-names, pinctrl-0: Please refer to pinctrl-bindings.txt
> +
> +Example:
> +sound at fffa0000 {
> +	compatible = "atmel,atmel_ac97c";
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pinctrl_ac97>;
> +	reg = <0xfffa0000 0x4000>;
> +	interrupts = <18 IRQ_TYPE_LEVEL_HIGH 5>;
> +
> +	atmel,reset-pin = <&pioC 29 GPIO_ACTIVE_LOW>;
> +};
> diff --git a/sound/atmel/ac97c.c b/sound/atmel/ac97c.c
> index 9a13875..b84432b 100644
> --- a/sound/atmel/ac97c.c
> +++ b/sound/atmel/ac97c.c
> @@ -22,6 +22,9 @@
>  #include <linux/gpio.h>
>  #include <linux/types.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of_device.h>
>  
>  #include <sound/core.h>
>  #include <sound/initval.h>
> @@ -901,6 +904,47 @@ static void atmel_ac97c_reset(struct atmel_ac97c *chip)
>  	}
>  }
>  
> +#ifdef CONFIG_OF
> +static const struct of_device_id atmel_ac97c_dt_ids[] = {
> +	{ .compatible = "atmel,atmel_ac97c", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, atmel_ac97c_dt_ids);
> +
> +static struct ac97c_platform_data *atmel_ac97c_probe_dt(struct device *dev)
> +{
> +	struct ac97c_platform_data *pdata;
> +	struct device_node *node = dev->of_node;
> +	const struct of_device_id *match;
> +
> +	if (!node) {
> +		dev_err(dev, "Device does not have associated DT data\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	match = of_match_device(atmel_ac97c_dt_ids, dev);
> +	if (!match) {
> +		dev_err(dev, "Unknown device model\n");
> +		return ERR_PTR(-EINVAL);
> +	}

You probably don't need that, it will always match. You would need it if
you were actually using match (for example to get the .data member).

> +
> +	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		return ERR_PTR(-ENOMEM);
> +
> +	pdata->reset_pin = of_get_named_gpio(dev->of_node,
> +					     "atmel,reset-pin", 0);
> +
> +	return pdata;
> +}
> +#else
> +static struct ac97c_platform_data *atmel_ac97c_probe_dt(struct device *dev)
> +{
> +	dev_err(dev, "no platform data defined\n");
> +	return ERR_PTR(-ENXIO);
> +}
> +#endif
> +
>  static int atmel_ac97c_probe(struct platform_device *pdev)
>  {
>  	struct snd_card			*card;
> @@ -921,10 +965,11 @@ static int atmel_ac97c_probe(struct platform_device *pdev)
>  		return -ENXIO;
>  	}
>  
> -	pdata = pdev->dev.platform_data;
> +	pdata = dev_get_platdata(&pdev->dev);
>  	if (!pdata) {
> -		dev_dbg(&pdev->dev, "no platform data\n");
> -		return -ENXIO;
> +		pdata = atmel_ac97c_probe_dt(&pdev->dev);
> +		if (IS_ERR(pdata))
> +			return PTR_ERR(pdata);
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> @@ -1208,6 +1253,7 @@ static struct platform_driver atmel_ac97c_driver = {
>  		.name	= "atmel_ac97c",
>  		.owner	= THIS_MODULE,
>  		.pm	= ATMEL_AC97C_PM_OPS,
> +		.of_match_table = of_match_ptr(atmel_ac97c_dt_ids),
>  	},
>  };
>  module_platform_driver(atmel_ac97c_driver);
> -- 
> 1.9.2
> 
> 
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-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com