[alsa-devel] [PATCH] ASoC: Intel: use 19.2 MCLK instead of the bit clock for bytcr_rt5651.c machine driver

[Pietro]

Hi Pierre,

If needed I can patch it in one of these ways:
- Split the driver in one for Baytrail Platforms, and another one for Cherryview
- Use conditional compilations, with an addictional Kernel option to select between Baytrail and Cherryview
- Select the proper way to set the clock at runtime by detect the platform in the driver context (Some help needed here to distinguish between the 2 platforms)

Or just tell me if you think this is not needed, because the clock driver you are working on will be released soon.

Pietro

On Friday 03 June 2016 11:15:00 Pierre-Louis Bossart wrote:
> On 6/3/16 10:33 AM, Pietro Di Costanzo wrote:
> > Use the MCLK to solve audio quality issues found on some Cherryview-based platforms
> >
> > Signed-off-by: Pietro Di Costanzo <pxpert at gmail.com>
> 
> Thanks Pietro.
> this can't be merged as is as it wouldn't work on Baytrail platforms. I 
> will merge it with the clock driver we are working to have a single 
> driver that works for both cases.
> 
> > ---
> >  sound/soc/intel/boards/bytcr_rt5651.c | 84 +++++++++++++++++++++++++++++++----
> >  1 file changed, 75 insertions(+), 9 deletions(-)
> >
> > diff --git a/sound/soc/intel/boards/bytcr_rt5651.c b/sound/soc/intel/boards/bytcr_rt5651.c
> > index 35f591e..e51ea5b 100644
> > --- a/sound/soc/intel/boards/bytcr_rt5651.c
> > +++ b/sound/soc/intel/boards/bytcr_rt5651.c
> > @@ -31,11 +31,76 @@
> >  #include "../../codecs/rt5651.h"
> >  #include "../atom/sst-atom-controls.h"
> >
> > +#define CHT_PLAT_CLK_3_HZ       19200000
> > +#define CHT_CODEC_DAI_5651   "rt5651-aif1"
> > +
> > +struct cht_acpi_card {
> > +	char *codec_id;
> > +	int codec_type;
> > +	struct snd_soc_card *soc_card;
> > +};
> > +
> > +struct cht_mc_private {
> > +	struct snd_soc_jack jack;
> > +	struct cht_acpi_card *acpi_card;
> > +};
> > +
> > +
> > +static inline struct snd_soc_dai *cht_get_codec_dai(struct snd_soc_card *card)
> > +{
> > +	struct snd_soc_pcm_runtime *rtd;
> > +
> > +	list_for_each_entry(rtd, &card->rtd_list, list) {
> > +		if (!strncmp(rtd->codec_dai->name, CHT_CODEC_DAI_5651,
> > +			  strlen(CHT_CODEC_DAI_5651)))
> > +			return rtd->codec_dai;
> > +	}
> > +	return NULL;
> > +}
> > +
> > +static int platform_clock_control(struct snd_soc_dapm_widget *w,
> > +		struct snd_kcontrol *k, int  event)
> > +{
> > +	struct snd_soc_dapm_context *dapm = w->dapm;
> > +	struct snd_soc_card *card = dapm->card;
> > +	struct snd_soc_dai *codec_dai;
> > +	int ret;
> > +
> > +	codec_dai = cht_get_codec_dai(card);
> > +	if (!codec_dai) {
> > +		dev_err(card->dev, "Codec dai not found; Unable to set platform clock\n");
> > +		return -EIO;
> > +	}
> > +
> > +	if (!SND_SOC_DAPM_EVENT_OFF(event))
> > +		return 0;
> > +
> > +	/* Set codec sysclk source to its internal clock because codec PLL will
> > +	 * be off when idle and MCLK will also be off by ACPI when codec is
> > +	 * runtime suspended. Codec needs clock for jack detection and button
> > +	 * press.
> > +	 */
> > +	ret = snd_soc_dai_set_sysclk(codec_dai, RT5651_SCLK_S_RCCLK,
> > +			0, SND_SOC_CLOCK_IN);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "can't set codec sysclk: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +
> > +
> > +
> >  static const struct snd_soc_dapm_widget byt_rt5651_widgets[] = {
> >  	SND_SOC_DAPM_HP("Headphone", NULL),
> >  	SND_SOC_DAPM_MIC("Headset Mic", NULL),
> >  	SND_SOC_DAPM_MIC("Internal Mic", NULL),
> >  	SND_SOC_DAPM_SPK("Speaker", NULL),
> > +	SND_SOC_DAPM_SUPPLY("Platform Clock", SND_SOC_NOPM, 0, 0,
> > +			platform_clock_control, SND_SOC_DAPM_POST_PMD),
> > +
> >  };
> >
> >  static const struct snd_soc_dapm_route byt_rt5651_audio_map[] = {
> > @@ -52,6 +117,9 @@ static const struct snd_soc_dapm_route byt_rt5651_audio_map[] = {
> >  	{"Headphone", NULL, "HPOR"},
> >  	{"Speaker", NULL, "LOUTL"},
> >  	{"Speaker", NULL, "LOUTR"},
> > +	{"Headphone", NULL, "Platform Clock"},
> > +	{"Speaker", NULL, "Platform Clock"},
> > +
> >  };
> >
> >  static const struct snd_soc_dapm_route byt_rt5651_intmic_dmic1_map[] = {
> > @@ -93,7 +161,13 @@ static int byt_rt5651_aif1_hw_params(struct snd_pcm_substream *substream,
> >  	struct snd_soc_dai *codec_dai = rtd->codec_dai;
> >  	int ret;
> >
> > -	snd_soc_dai_set_bclk_ratio(codec_dai, 50);
> > +	/* set codec PLL source to the 19.2MHz platform clock (MCLK) */
> > +	ret = snd_soc_dai_set_pll(codec_dai, 0, RT5651_PLL1_S_MCLK,
> > +				  CHT_PLAT_CLK_3_HZ, params_rate(params) * 512);
> > +	if (ret < 0) {
> > +		dev_err(rtd->dev, "can't set codec pll: %d\n", ret);
> > +		return ret;
> > +	}
> >
> >  	ret = snd_soc_dai_set_sysclk(codec_dai, RT5651_SCLK_S_PLL1,
> >  				     params_rate(params) * 512,
> > @@ -103,14 +177,6 @@ static int byt_rt5651_aif1_hw_params(struct snd_pcm_substream *substream,
> >  		return ret;
> >  	}
> >
> > -	ret = snd_soc_dai_set_pll(codec_dai, 0, RT5651_PLL1_S_BCLK1,
> > -				  params_rate(params) * 50,
> > -				  params_rate(params) * 512);
> > -	if (ret < 0) {
> > -		dev_err(rtd->dev, "can't set codec pll: %d\n", ret);
> > -		return ret;
> > -	}
> > -
> >  	return 0;
> >  }
> >
> >
>