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

[Maxime Ripard]

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 at 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 at 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
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