Re: [PATCH v2] ASoC: imx-wm8960: Let codec driver enable/disable its MCLK

From: Nicolin Chen
Date: Fri Mar 24 2017 - 13:48:15 EST


On Fri, Mar 24, 2017 at 11:14:48AM +0200, Daniel Baluta wrote:
> From: Daniel Baluta <daniel.baluta@xxxxxxx>
>
> WM8962 needs its MCLK when powerup in wm8962_resume(). Thus it's better
> to control the MCLK in codec driver. Thus remove the clock enable in
> machine driver accordingly.
>
> While at it, get rid of imx_wm8962_remove function since it is now
> empty.
>
> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
> ---
> Changes since v1:
> * s/wm8960/imx-wm890/ in subject prefix

imx-wm8962 vs imx-wm8960 :)

> * s/dirver/driver in commit message
> * took ownership over the patch from Nicolin Chen
> as per his agreement.
>
> sound/soc/fsl/imx-wm8962.c | 40 ++++++++--------------------------------
> 1 file changed, 8 insertions(+), 32 deletions(-)
>
> diff --git a/sound/soc/fsl/imx-wm8962.c b/sound/soc/fsl/imx-wm8962.c
> index 1b60958..3d894d9 100644
> --- a/sound/soc/fsl/imx-wm8962.c
> +++ b/sound/soc/fsl/imx-wm8962.c
> @@ -33,7 +33,6 @@ struct imx_wm8962_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;
> };
>
> @@ -163,6 +162,7 @@ static int imx_wm8962_probe(struct platform_device *pdev)
> struct imx_priv *priv = &card_priv;
> struct i2c_client *codec_dev;
> struct imx_wm8962_data *data;
> + struct clk *codec_clk;
> int int_port, ext_port;
> int ret;
>
> @@ -231,19 +231,14 @@ static int imx_wm8962_probe(struct platform_device *pdev)
> goto fail;
> }
>
> - data->codec_clk = devm_clk_get(&codec_dev->dev, NULL);
> - if (IS_ERR(data->codec_clk)) {
> - ret = PTR_ERR(data->codec_clk);
> + codec_clk = devm_clk_get(&codec_dev->dev, NULL);

I actually just noticed a problem here -- not from your change but
it existed in the first place. IIRC, devm_clk_get() would only be
properly clk_put() for this driver if we passed pdev->dev while we
are using codec_dev->dev. So here we probably should use clk_get()
instead and call a clk_put() right after fetching the clock rate.

Would you please fix this issue along with this change since you
are touching the exact same line of the code?

Thanks
Nicolin

> + if (IS_ERR(codec_clk)) {
> + ret = PTR_ERR(codec_clk);
> dev_err(&codec_dev->dev, "failed to get codec clk: %d\n", ret);
> goto fail;
> }
>
> - data->clk_frequency = clk_get_rate(data->codec_clk);
> - ret = clk_prepare_enable(data->codec_clk);
> - if (ret) {
> - dev_err(&codec_dev->dev, "failed to enable codec clk: %d\n", ret);
> - goto fail;
> - }
> + data->clk_frequency = clk_get_rate(codec_clk);
>
> data->dai.name = "HiFi";
> data->dai.stream_name = "HiFi";
> @@ -258,10 +253,10 @@ static int imx_wm8962_probe(struct platform_device *pdev)
> data->card.dev = &pdev->dev;
> ret = snd_soc_of_parse_card_name(&data->card, "model");
> if (ret)
> - goto clk_fail;
> + goto fail;
> ret = snd_soc_of_parse_audio_routing(&data->card, "audio-routing");
> if (ret)
> - goto clk_fail;
> + goto fail;
> data->card.num_links = 1;
> data->card.owner = THIS_MODULE;
> data->card.dai_link = &data->dai;
> @@ -277,16 +272,9 @@ static int imx_wm8962_probe(struct platform_device *pdev)
> ret = devm_snd_soc_register_card(&pdev->dev, &data->card);
> if (ret) {
> dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
> - goto clk_fail;
> + goto fail;
> }
>
> - of_node_put(ssi_np);
> - of_node_put(codec_np);
> -
> - return 0;
> -
> -clk_fail:
> - clk_disable_unprepare(data->codec_clk);
> fail:
> of_node_put(ssi_np);
> of_node_put(codec_np);
> @@ -294,17 +282,6 @@ static int imx_wm8962_probe(struct platform_device *pdev)
> return ret;
> }