Re: [PATCH] ASoC: Intel: sof_rt5682: add 512FS MCLK clock configuration

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

On 1/18/22 2:49 AM, Mac Chiang wrote:
> codec system clock source support 512FS MCLK synchronous directly, so
> no need to set PLL configuration when MCLK 24.576MHz.
> 
> Suggested-by: Shuming Fan <shumingf@realtek.com>
> Signed-off-by: Mac Chiang <mac.chiang@intel.com>
> ---
>  sound/soc/intel/boards/sof_rt5682.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/sound/soc/intel/boards/sof_rt5682.c b/sound/soc/intel/boards/sof_rt5682.c
> index bd6d2e7dea53..a6efffc14cad 100644
> --- a/sound/soc/intel/boards/sof_rt5682.c
> +++ b/sound/soc/intel/boards/sof_rt5682.c
> @@ -61,7 +61,6 @@
>  #define SOF_MAX98390_SPEAKER_AMP_PRESENT	BIT(24)
>  #define SOF_MAX98390_TWEETER_SPEAKER_PRESENT	BIT(25)
>  
> -
>  /* Default: MCLK on, MCLK 19.2M, SSP0  */
>  static unsigned long sof_rt5682_quirk = SOF_RT5682_MCLK_EN |
>  					SOF_RT5682_SSP_CODEC(0);
> @@ -362,6 +361,9 @@ static int sof_rt5682_hw_params(struct snd_pcm_substream *substream,
>  	if (sof_rt5682_quirk & SOF_RT5682S_HEADPHONE_CODEC_PRESENT) {
>  		pll_id = RT5682S_PLL2;
>  		clk_id = RT5682S_SCLK_S_PLL2;
> +
> +		if (pll_in == 24576000)
> +			clk_id = RT5682S_SCLK_S_MCLK;

this case only affects the RT5682s case.

>  	} else {
>  		pll_id = RT5682_PLL1;
>  		clk_id = RT5682_SCLK_S_PLL1;

for the RT5682 we keep using the PLL. Is this intentional?

I also wonder if we can avoid the hard-coding. Can we use e.g.

if (pll_in == params_rate(params) * 512)

?


> @@ -369,11 +371,14 @@ static int sof_rt5682_hw_params(struct snd_pcm_substream *substream,
>  
>  	pll_out = params_rate(params) * 512;
>  
> -	/* Configure pll for codec */
> -	ret = snd_soc_dai_set_pll(codec_dai, pll_id, pll_source, pll_in,
> -				  pll_out);
> -	if (ret < 0)
> -		dev_err(rtd->dev, "snd_soc_dai_set_pll err = %d\n", ret);
> +	/* when MCLK is 512FS, no need to set PLL configuration additionally. */
> +	if (pll_in != 24576000) {

can we use if (pll_in == pll_out) ?

> +		/* Configure pll for codec */
> +		ret = snd_soc_dai_set_pll(codec_dai, pll_id, pll_source, pll_in,
> +					  pll_out);
> +		if (ret < 0)
> +			dev_err(rtd->dev, "snd_soc_dai_set_pll err = %d\n", ret);
> +	}
>  
>  	/* Configure sysclk for codec */
>  	ret = snd_soc_dai_set_sysclk(codec_dai, clk_id,
>