Re: [linux-sunxi] [PATCH 1/3] ASoC: sun4i-i2s: Add set_tdm_slot functionality

[Chen-Yu Tsai]

On Mon, Jan 29, 2018 at 3:34 PM, Code Kipper <codekipper@xxxxxxxxx> wrote:
> On 29 January 2018 at 02:50, Chen-Yu Tsai <wens@xxxxxxxx> wrote:
>> On Wed, Jan 24, 2018 at 10:10 PM,  <codekipper@xxxxxxxxx> wrote:
>>> From: Marcus Cooper <codekipper@xxxxxxxxx>
>>>
>>> Some codecs require a different amount of a bit clocks per frame than
>>> what is calculated by the sample width. Use the tdm slot bindings to
>>> provide this mechanism.
>>>
>>> Signed-off-by: Marcus Cooper <codekipper@xxxxxxxxx>
>>> ---
>>>  sound/soc/sunxi/sun4i-i2s.c | 23 +++++++++++++++++++++--
>>>  1 file changed, 21 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
>>> index dca1143c1150..d7a9141514cf 100644
>>> --- a/sound/soc/sunxi/sun4i-i2s.c
>>> +++ b/sound/soc/sunxi/sun4i-i2s.c
>>> @@ -96,6 +96,7 @@
>>>  #define SUN8I_I2S_CTRL_BCLK_OUT                        BIT(18)
>>>  #define SUN8I_I2S_CTRL_LRCK_OUT                        BIT(17)
>>>
>>> +#define SUN8I_I2S_FMT0_LRCK_MAX_PERIOD         (GENMASK(17, 8) >> 8)
>>>  #define SUN8I_I2S_FMT0_LRCK_PERIOD_MASK                GENMASK(17, 8)
>>>  #define SUN8I_I2S_FMT0_LRCK_PERIOD(period)     ((period - 1) << 8)
>>>
>>> @@ -193,6 +194,9 @@ struct sun4i_i2s {
>>>         struct regmap_field     *field_rxchansel;
>>>
>>>         const struct sun4i_i2s_quirks   *variant;
>>> +
>>> +       unsigned int    tdm_slots;
>>> +       unsigned int    slot_width;
>>>  };
>>>
>>>  struct sun4i_i2s_clk_div {
>>> @@ -344,7 +348,7 @@ static int sun4i_i2s_set_clk_rate(struct snd_soc_dai *dai,
>>>         if (i2s->variant->has_fmt_set_lrck_period)
>>>                 regmap_update_bits(i2s->regmap, SUN4I_I2S_FMT0_REG,
>>>                                    SUN8I_I2S_FMT0_LRCK_PERIOD_MASK,
>>> -                                  SUN8I_I2S_FMT0_LRCK_PERIOD(32));
>>> +                                  SUN8I_I2S_FMT0_LRCK_PERIOD(word_size));
>>>
>>>         return 0;
>>>  }
>>> @@ -418,7 +422,8 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
>>>                            sr + i2s->variant->fmt_offset);
>>>
>>>         return sun4i_i2s_set_clk_rate(dai, params_rate(params),
>>> -                                     params_width(params));
>>> +                                     i2s->tdm_slots ?
>>> +                                     i2s->slot_width : params_width(params));
>>>  }
>>>
>>>  static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
>>> @@ -691,6 +696,19 @@ static int sun4i_i2s_set_sysclk(struct snd_soc_dai *dai, int clk_id,
>>>         return 0;
>>>  }
>>>
>>> +static int sun4i_i2s_set_dai_tdm_slot(struct snd_soc_dai *dai,
>>> +       unsigned int tx_mask, unsigned int rx_mask,
>>> +       int slots, int width)
>>> +{
>>> +       struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
>>> +
>>> +       i2s->tdm_slots = slots;
>>> +
>>> +       i2s->slot_width = width;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>
>> IIRC some of the DAI controllers actually support TDM. Would this
>> change conflict with that in the future?
>
> Hi Wens,
> I'm not sure..I was looking for a clean example of being able to
> override the number of bclks in the lrclk width and some other
> devices(Rpi) were doing it this way.  I open to suggestions,

I'm not familiar with the issue either. If Mark doesn't have any
objections, we could merge it for now, and fix it later if there
are any complications.

BTW, you didn't provide a device tree example (if any) for how
to use this.

ChenYu

> BR,
> CK
>>
>> Thanks
>> ChenYu
>>
>>>  static const struct snd_soc_dai_ops sun4i_i2s_dai_ops = {
>>>         .hw_params      = sun4i_i2s_hw_params,
>>>         .set_fmt        = sun4i_i2s_set_fmt,
>>> @@ -698,6 +716,7 @@ static const struct snd_soc_dai_ops sun4i_i2s_dai_ops = {
>>>         .shutdown       = sun4i_i2s_shutdown,
>>>         .startup        = sun4i_i2s_startup,
>>>         .trigger        = sun4i_i2s_trigger,
>>> +       .set_tdm_slot   = sun4i_i2s_set_dai_tdm_slot,
>>>  };
>>>
>>>  static int sun4i_i2s_dai_probe(struct snd_soc_dai *dai)
>>> --
>>> 2.16.0
>>>
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