[alsa-devel] [PATCH 03/11] ASoC: fsl: add sgtl5000 clock support for imx-sgtl5000

[Shawn Guo]

On Fri, Apr 27, 2012 at 03:02:57PM +0800, Richard Zhao wrote:
> From: Richard Zhao <richard.zhao at linaro.org>
> 
> It tries to clk_get the clock. And if it failed, it assumes the clock
> by default enabled.
> 
> Signed-off-by: Richard Zhao <richard.zhao at freescale.com>
> ---
>  sound/soc/fsl/imx-sgtl5000.c |   40 ++++++++++++++++++++++++++++++++--------
>  1 files changed, 32 insertions(+), 8 deletions(-)
> 
> diff --git a/sound/soc/fsl/imx-sgtl5000.c b/sound/soc/fsl/imx-sgtl5000.c
> index 73b935e..3a729ca 100644
> --- a/sound/soc/fsl/imx-sgtl5000.c
> +++ b/sound/soc/fsl/imx-sgtl5000.c
> @@ -13,6 +13,8 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_platform.h>
> +#include <linux/of_i2c.h>
> +#include <linux/clk.h>
>  #include <sound/soc.h>
>  
>  #include "../codecs/sgtl5000.h"
> @@ -25,6 +27,7 @@ struct imx_sgtl5000_data {
>  	struct snd_soc_card card;
>  	char codec_dai_name[DAI_NAME_SIZE];
>  	char platform_name[DAI_NAME_SIZE];
> +	struct clk *codec_clk;
>  	unsigned int clk_frequency;
>  };
>  
> @@ -58,6 +61,7 @@ static int __devinit imx_sgtl5000_probe(struct platform_device *pdev)
>  	struct device_node *np = pdev->dev.of_node;
>  	struct device_node *ssi_np, *codec_np;
>  	struct platform_device *ssi_pdev;
> +	struct i2c_client *codec_dev;
>  	struct imx_sgtl5000_data *data;
>  	int int_port, ext_port;
>  	int ret;
> @@ -113,6 +117,11 @@ static int __devinit imx_sgtl5000_probe(struct platform_device *pdev)
>  		ret = -EINVAL;
>  		goto fail;
>  	}
> +	codec_dev = of_find_i2c_device_by_node(codec_np);
> +	if (!codec_dev) {
> +		dev_err(&pdev->dev, "failed to find codec platform device\n");
> +		return -EINVAL;
> +	}

What if the codec is accessed via SPI bus on some machines?

>  
>  	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>  	if (!data) {
> @@ -120,11 +129,20 @@ static int __devinit imx_sgtl5000_probe(struct platform_device *pdev)
>  		goto fail;
>  	}
>  
> -	ret = of_property_read_u32(codec_np, "clock-frequency",
> -				   &data->clk_frequency);
> -	if (ret) {
> -		dev_err(&pdev->dev, "clock-frequency missing or invalid\n");
> -		goto fail;
> +	data->codec_clk = clk_get(&codec_dev->dev, NULL);

It's a clock of sgtl5000 codec.  I feel it makes more sense to have
sgtl5000 device driver than machine driver to manage this clock.

Regards,
Shawn

> +	if (IS_ERR(data->codec_clk)) {
> +		/* assuming clock enabled by default */
> +		data->codec_clk = NULL;
> +		ret = of_property_read_u32(codec_np, "clock-frequency",
> +					&data->clk_frequency);
> +		if (ret) {
> +			dev_err(&codec_dev->dev,
> +				"clock-frequency missing or invalid\n");
> +			goto fail;
> +		}
> +	} else {
> +		data->clk_frequency = clk_get_rate(data->codec_clk);
> +		clk_prepare_enable(data->codec_clk);
>  	}