Re: [alsa-devel] [PATCH v2] ASoC: da7219: read fmw property to get mclk for non-dts systems

[Pierre-Louis Bossart]

On 4/30/18 4:23 AM, Akshu Agrawal wrote:
> Non-dts based systems can use ACPI DSDT to pass on the mclk
> to da7219.
> This enables da7219 mclk to be linked to system clock.
> Enable/Disable of the mclk is already handled in the codec so
> platform drivers don't have to explicitly do handling of mclk.
>
> Signed-off-by: Akshu Agrawal <akshu.agrawal@xxxxxxx>
> ---
> v2: Fixed kbuild error
>   include/sound/da7219.h    | 2 ++
>   sound/soc/codecs/da7219.c | 7 ++++++-
>   2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/include/sound/da7219.h b/include/sound/da7219.h
> index 1bfcb16..df7ddf4 100644
> --- a/include/sound/da7219.h
> +++ b/include/sound/da7219.h
> @@ -38,6 +38,8 @@ struct da7219_pdata {
>   
>   	const char *dai_clks_name;
>   
> +	const char *mclk_name;
> +
>   	/* Mic */
>   	enum da7219_micbias_voltage micbias_lvl;
>   	enum da7219_mic_amp_in_sel mic_amp_in_sel;
> diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c
> index 980a6a8..aed68a4 100644
> --- a/sound/soc/codecs/da7219.c
> +++ b/sound/soc/codecs/da7219.c
> @@ -1624,6 +1624,8 @@ static struct da7219_pdata *da7219_fw_to_pdata(struct snd_soc_component *compone
>   		dev_warn(dev, "Using default clk name: %s\n",
>   			 pdata->dai_clks_name);
>   
> +	device_property_read_string(dev, "dlg,mclk-name", &pdata->mclk_name);
> +
>   	if (device_property_read_u32(dev, "dlg,micbias-lvl", &of_val32) >= 0)
>   		pdata->micbias_lvl = da7219_fw_micbias_lvl(dev, of_val32);
>   	else
> @@ -1905,7 +1907,10 @@ static int da7219_probe(struct snd_soc_component *component)
>   	da7219_handle_pdata(component);
>   
>   	/* Check if MCLK provided */
> -	da7219->mclk = devm_clk_get(component->dev, "mclk");
> +	if (da7219->pdata->mclk_name)
> +		da7219->mclk = clk_get(NULL, da7219->pdata->mclk_name);
> +	if (!da7219->mclk)
> +		da7219->mclk = devm_clk_get(component->dev, "mclk");

this looks weird, why are you using different clk functions depending on 
the existence of a _DSD property? Why not just change the name and keep 
the same flow, e.g something like

if(!da7219->pdata->mclk_name)
	da7219->pdata->mclk_name = "mclk";
da7219->mclk = devm_clk_get(component->dev, da7219->pdata->mclk_name);


>   	if (IS_ERR(da7219->mclk)) {
>   		if (PTR_ERR(da7219->mclk) != -ENOENT) {
>   			ret = PTR_ERR(da7219->mclk);