Re: [alsa-devel] [PATCH 20/21] ASoC: sun4i-i2s: Add support for TDM slots

Hi,

On Tue, Aug 20, 2019 at 08:46:30AM +0300, Sergey Suloev wrote:

Hi, Maxime,

On 8/19/19 10:25 PM, Maxime Ripard wrote:

...

From: Maxime Ripard maxime.ripard@bootlin.com

The i2s controller supports TDM, for up to 8 slots. Let's support the TDM API.

Signed-off-by: Maxime Ripard maxime.ripard@bootlin.com

sound/soc/sunxi/sun4i-i2s.c | 40 ++++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c index 0dac09814b65..4f76daeaaed7 100644 --- a/sound/soc/sunxi/sun4i-i2s.c +++ b/sound/soc/sunxi/sun4i-i2s.c @@ -168,6 +168,8 @@ struct sun4i_i2s { struct reset_control *rst; unsigned int mclk_freq;

• unsigned int slots;
• unsigned int slot_width; struct snd_dmaengine_dai_dma_data capture_dma_data; struct snd_dmaengine_dai_dma_data playback_dma_data;

@@ -287,7 +289,7 @@ static bool sun4i_i2s_oversample_is_valid(unsigned int oversample) static int sun4i_i2s_set_clk_rate(struct snd_soc_dai *dai, unsigned int rate,

• 		  unsigned int channels,
  

• 		  unsigned int slots,
  	  unsigned int word_size)
  

  { struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);

@@ -335,7 +337,7 @@ static int sun4i_i2s_set_clk_rate(struct snd_soc_dai *dai, bclk_parent_rate = i2s->variant->get_bclk_parent_rate(i2s); bclk_div = sun4i_i2s_get_bclk_div(i2s, bclk_parent_rate,

• 			  rate, channels, word_size);
  

• 			  rate, slots, word_size);
  

  if (bclk_div < 0) { dev_err(dai->dev, "Unsupported BCLK divider: %d\n", bclk_div); return -EINVAL;

@@ -419,6 +421,10 @@ static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s, const struct snd_pcm_hw_params *params) { unsigned int channels = params_channels(params);

• unsigned int slots = channels;
• if (i2s->slots)

• slots = i2s->slots;
  

  /* Map the channels for playback and capture */ regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_MAP_REG, 0x76543210);

@@ -428,7 +434,6 @@ static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s, regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG, SUN4I_I2S_CHAN_SEL_MASK, SUN4I_I2S_CHAN_SEL(channels));

• regmap_update_bits(i2s->regmap, SUN8I_I2S_RX_CHAN_SEL_REG, SUN4I_I2S_CHAN_SEL_MASK, SUN4I_I2S_CHAN_SEL(channels));

@@ -452,10 +457,18 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream, struct snd_soc_dai *dai) { struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);

• unsigned int word_size = params_width(params); unsigned int channels = params_channels(params);
• unsigned int slots = channels; int ret, sr, wss; u32 width;
• if (i2s->slots)

• slots = i2s->slots;
  

• if (i2s->slot_width)

• word_size = i2s->slot_width;
  

• ret = i2s->variant->set_chan_cfg(i2s, params); if (ret < 0) { dev_err(dai->dev, "Invalid channel configuration\n");

@@ -477,15 +490,14 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream, if (sr < 0) return -EINVAL;

• wss = i2s->variant->get_wss(i2s, params_width(params));

• wss = i2s->variant->get_wss(i2s, word_size); if (wss < 0) return -EINVAL; regmap_field_write(i2s->field_fmt_wss, wss); regmap_field_write(i2s->field_fmt_sr, sr);

• return sun4i_i2s_set_clk_rate(dai, params_rate(params),

• 		      channels, params_width(params));
  

• return sun4i_i2s_set_clk_rate(dai, params_rate(params), slots, word_size); } static int sun4i_i2s_set_soc_fmt(const struct sun4i_i2s *i2s,

@@ -785,10 +797,26 @@ static int sun4i_i2s_set_sysclk(struct snd_soc_dai *dai, int clk_id, return 0; } +static int sun4i_i2s_set_tdm_slot(struct snd_soc_dai *dai,

• 		  unsigned int tx_mask, unsigned int rx_mask,
  

• 		  int slots, int slot_width)
  

+{

• struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
• if (slots > 8)

• return -EINVAL;
  

• i2s->slots = slots;
• i2s->slot_width = slot_width;
• return 0;

+}

• static const struct snd_soc_dai_ops sun4i_i2s_dai_ops = { .hw_params = sun4i_i2s_hw_params, .set_fmt = sun4i_i2s_set_fmt, .set_sysclk = sun4i_i2s_set_sysclk,
• .set_tdm_slot = sun4i_i2s_set_tdm_slot, .trigger = sun4i_i2s_trigger, };

it seems like you forgot to implement sun4i_i2s_dai_ops.set_bclk_ratio because, as I far as I understand, it should alter tdm slots functionality indirectly.

As far as I can see, while this indeed changes a few things on the TDM setup, it's optional, orthogonal and it has a single user in the tree (some intel platform card).

So I'd say that if someone ever needs it, we can have it, but it's not a blocker.

Maxime

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