On Wed, 14 Aug 2019 at 13:08, Maxime Ripard [off-list ref] wrote:

Hi,

On Wed, Aug 14, 2019 at 08:08:41AM +0200, codekipper@gmail.com wrote:

quoted

From: Marcus Cooper <redacted>

Codecs without a control connection such as i2s based HDMI audio and
the Pine64 DAC require a different amount of 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 <redacted>
---
 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 8201334a059b..7c37b6291df0 100644
--- a/sound/soc/sunxi/sun4i-i2s.c
+++ b/sound/soc/sunxi/sun4i-i2s.c

@@ -195,6 +195,9 @@ 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 {

@@ -346,7 +349,7 @@ 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));


      /* Set sign extension to pad out LSB with 0 */
      regmap_field_write(i2s->field_fmt_sext, 0);

@@ -450,7 +453,8 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
      regmap_field_write(i2s->field_fmt_sr, sr);

      return sun4i_i2s_set_clk_rate(dai, params_rate(params),
-                                   params_width(params));
+                                   i2s->tdm_slots ?
+                                   i2s->slot_width : params_width(params));

This is slightly more complicated than that.

At this point we're only supporting 2 channels with fixed slot
settings. I've added a comment to state
that we're using the tdm_slot at the moment as an indicator to
override the slot width. Do you think
that is enough for now?.

Thanks,
CK

On the H3 (and all related ones), the CHAN_CFG_TX_SLOT_NUM and
_RX_SLOT_NUM fields in the CHAN_CFG register need to be set to the
number of slots as well.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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