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

[Code Kipper]

On 29 January 2018 at 08:38, Chen-Yu Tsai <wens at csie.org> wrote:
> On Mon, Jan 29, 2018 at 3:34 PM, Code Kipper <codekipper at gmail.com> wrote:
>> On 29 January 2018 at 02:50, Chen-Yu Tsai <wens at csie.org> wrote:
>>> On Wed, Jan 24, 2018 at 10:10 PM,  <codekipper at gmail.com> wrote:
>>>> From: Marcus Cooper <codekipper at gmail.com>
>>>>
>>>> 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 at gmail.com>
>>>> ---
>>>>  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.

Hi Wens,

here is an example that I use for the Pine64 audio hat.
https://github.com/codekipper/linux-sunxi/commit/faa9dfba955bf71ca23b089b1cb678a14443216f#diff-1473a38b339685d191c5a87aab9c0fdfR80

I've done the same on the A64 for HDMI and analog audio which both use
the i2s and seem to require 32bit LRCK width.

BR,
CK

>
> 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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