[alsa-devel] [PATCH v2] ASoC: rt5670: add set_bclk_ratio in dai ops

[Pierre-Louis Bossart]

On 9/12/17 11:35 PM, Bard Liao wrote:
>> -----Original Message-----
>> From: Pierre-Louis Bossart [mailto:pierre-louis.bossart at linux.intel.com]
>> Sent: Tuesday, September 12, 2017 10:54 PM
>> To: Bard Liao; broonie at kernel.org; lgirdwood at gmail.com
>> Cc: Oder Chiou; Jack Yu; alsa-devel at alsa-project.org; lars at metafoo.de;
>> tiwai at suse.de; Shuming [范書銘]; Flove(HsinFu)
>> Subject: Re: [alsa-devel] [PATCH v2] ASoC: rt5670: add set_bclk_ratio in dai ops
>>
>> On 9/12/17 3:12 AM, Bard Liao wrote:
>>> We need to set a specific bit for 50 bclk rate. So add set_bclk_ratio
>>> function to set the bit.
>>
>> When is this supposed to be used? the cht_bsw_rt5672 machine driver uses
>> a 19.2MHz MCLK/2.4 MHz bclk, so there's a typical 50x ratio.
> 
> I think it should be used for all Intel platform. The bit will only be
> effective in PCM mode with TDM enabled. It will influence the data
> allocation format.
> 0: the dummy bits will be allocate at the end of each slot.
> 1: the dummy bits will be allocate at the end of all slots.
> For example, 50fs with 24 bits data length.
> 0: 24 bits slot0 data + 1 dummy bit + 24 bits slot1 data + 1 dummy bit
> 1: 24 bits slot0 data + 24 bits slot1 data + 2 dummy bits
> 
> I will do slight modification on the patch since the bit should be set for
> all bclk rate which is divisible by 50.

I am not sure I understand the 0: and 1: cases, and since we get audio 
today with this codec and a ratio of 200 (4 24-bit slots in DSP_B) I 
don't get what happens with this fix.

> 
>>
>>>
>>> Signed-off-by: Bard Liao <bardliao at realtek.com>
>>> ---
>>> v2:
>>> * add define for tdm data format select bit.
>>> ---
>>>    sound/soc/codecs/rt5670.c | 19 +++++++++++++++++++
>>>    sound/soc/codecs/rt5670.h |  4 ++++
>>>    2 files changed, 23 insertions(+)
>>>
>>> diff --git a/sound/soc/codecs/rt5670.c b/sound/soc/codecs/rt5670.c
>>> index 9545764..da7614c 100644
>>> --- a/sound/soc/codecs/rt5670.c
>>> +++ b/sound/soc/codecs/rt5670.c
>>> @@ -2582,6 +2582,24 @@ static int rt5670_set_tdm_slot(struct snd_soc_dai
>> *dai, unsigned int tx_mask,
>>>    	return 0;
>>>    }
>>>
>>> +static int rt5670_set_bclk_ratio(struct snd_soc_dai *dai, unsigned int ratio)
>>> +{
>>> +	struct snd_soc_codec *codec = dai->codec;
>>> +
>>> +	dev_dbg(codec->dev, "%s ratio=%d\n", __func__, ratio);
>>> +	if (dai->id != RT5670_AIF1)
>>> +		return 0;
>>> +
>>> +	if (ratio == 50)
>>> +		snd_soc_update_bits(codec, RT5670_GEN_CTRL3,
>>> +			RT5670_TDM_DATA_MODE_SEL,
>> RT5670_TDM_DATA_MODE_50FS);
>>> +	else
>>> +		snd_soc_update_bits(codec, RT5670_GEN_CTRL3,
>>> +			RT5670_TDM_DATA_MODE_SEL,
>> RT5670_TDM_DATA_MODE_NOR);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>>    static int rt5670_set_bias_level(struct snd_soc_codec *codec,
>>>    			enum snd_soc_bias_level level)
>>>    {
>>> @@ -2712,6 +2730,7 @@ static const struct snd_soc_dai_ops
>> rt5670_aif_dai_ops = {
>>>    	.set_fmt = rt5670_set_dai_fmt,
>>>    	.set_tdm_slot = rt5670_set_tdm_slot,
>>>    	.set_pll = rt5670_set_dai_pll,
>>> +	.set_bclk_ratio = rt5670_set_bclk_ratio,
>>>    };
>>>
>>>    static struct snd_soc_dai_driver rt5670_dai[] = {
>>> diff --git a/sound/soc/codecs/rt5670.h b/sound/soc/codecs/rt5670.h
>>> index 5ba485c..265df80 100644
>>> --- a/sound/soc/codecs/rt5670.h
>>> +++ b/sound/soc/codecs/rt5670.h
>>> @@ -1816,6 +1816,10 @@
>>>    #define RT5670_ZCD_HP_DIS			(0x0 << 15)
>>>    #define RT5670_ZCD_HP_EN			(0x1 << 15)
>>>
>>> +/* General Control 3 (0xfc) */
>>> +#define RT5670_TDM_DATA_MODE_SEL		(0x1 << 11)
>>> +#define RT5670_TDM_DATA_MODE_NOR		(0x0 << 11)
>>> +#define RT5670_TDM_DATA_MODE_50FS		(0x1 << 11)
>>>
>>>    /* Codec Private Register definition */
>>>    /* 3D Speaker Control (0x63) */
>>>
>>
>>
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