Unverified Commit 37e313cd authored by Bastien Curutchet's avatar Bastien Curutchet Committed by Mark Brown
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ASoC: ti: davinci-i2s: Add TDM support 



TDM is not supported by the McBSP driver. The McBSP datasheet does not
name explicitly TDM as a supported format but it is possible to configure
the McBSP to do TDM if all slots are used by McBSP.

Add TDM support. It uses single-phase frame. Slot width is used to
compute the McBSP's word length.

Implement the set_tdm_slot() hook of snd_soc_dai_ops struct. It only
supports TDM if all slots are used by McBSP.

The snd_soc_dai_driver's channels_max is updated from 2 to 128.

This was tested with BP_FC format on a platform designed off of
DAVINCI/OMAP_L138. A check is done in davinci_i2s_set_dai_fmt() to
prevent TDM to be used with BC_FC and BC_FP formats.

Signed-off-by: default avatarBastien Curutchet <bastien.curutchet@bootlin.com>
Acked-by: default avatarPeter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://msgid.link/r/20240402071213.11671-8-bastien.curutchet@bootlin.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 7dd7a6d2

sound/soc/ti/davinci-i2s.c

+87 −5
Original line number Diff line number Diff line
@@ -160,6 +160,9 @@ struct davinci_mcbsp_dev { 
	unsigned int fmt;

	int clk_div;

	bool i2s_accurate_sck;



	int tdm_slots;

	int slot_width;

};



static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev,
@@ -213,6 +216,63 @@ static void davinci_mcbsp_stop(struct davinci_mcbsp_dev *dev, int playback) 
	toggle_clock(dev, playback);

}



static int davinci_i2s_tdm_word_length(int tdm_slot_width)

{

	switch (tdm_slot_width) {

	case 8:

		return DAVINCI_MCBSP_WORD_8;

	case 12:

		return DAVINCI_MCBSP_WORD_12;

	case 16:

		return DAVINCI_MCBSP_WORD_16;

	case 20:

		return DAVINCI_MCBSP_WORD_20;

	case 24:

		return DAVINCI_MCBSP_WORD_24;

	case 32:

		return DAVINCI_MCBSP_WORD_32;

	default:

		return -EINVAL;

	}

}



static int davinci_i2s_set_tdm_slot(struct snd_soc_dai *cpu_dai,

				    unsigned int tx_mask,

				    unsigned int rx_mask,

				    int slots, int slot_width)

{

	struct davinci_mcbsp_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);



	dev_dbg(dev->dev, "slots %d, slot_width %d\n", slots, slot_width);



	if (slots > 128 || !slots) {

		dev_err(dev->dev, "Invalid number of slots\n");

		return -EINVAL;

	}



	if (rx_mask != (1 << slots) - 1) {

		dev_err(dev->dev, "Invalid RX mask (0x%08x) : all slots must be used by McBSP\n",

			rx_mask);

		return -EINVAL;

	}



	if (tx_mask != (1 << slots) - 1) {

		dev_err(dev->dev, "Invalid TX mask (0x%08x) : all slots must be used by McBSP\n",

			tx_mask);

		return -EINVAL;

	}



	if (davinci_i2s_tdm_word_length(slot_width) < 0) {

		dev_err(dev->dev, "%s: Unsupported slot_width %d\n", __func__, slot_width);

		return -EINVAL;

	}



	dev->tdm_slots = slots;

	dev->slot_width = slot_width;



	return 0;

}



#define DEFAULT_BITPERSAMPLE	16



static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
@@ -238,6 +298,11 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai, 
			DAVINCI_MCBSP_PCR_CLKRM;

		break;

	case SND_SOC_DAIFMT_BC_FP:

		if (dev->tdm_slots || dev->slot_width) {

			dev_err(dev->dev, "TDM is not supported for BC_FP format\n");

			return -EINVAL;

		}



		/*

		 * McBSP CLKR pin is the input for the Sample Rate Generator.

		 * McBSP FSR and FSX are driven by the Sample Rate Generator.
@@ -246,6 +311,11 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai, 
		pcr |= DAVINCI_MCBSP_PCR_SCLKME;

		break;

	case SND_SOC_DAIFMT_BC_FC:

		if (dev->tdm_slots || dev->slot_width) {

			dev_err(dev->dev, "TDM is not supported for BC_FC format\n");

			return -EINVAL;

		}



		/* codec is master */

		pcr = 0;

		break;
@@ -383,8 +453,14 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream, 


	master = dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK;

	fmt = params_format(params);

	if (dev->slot_width)

		mcbsp_word_length = davinci_i2s_tdm_word_length(dev->slot_width);

	else

		mcbsp_word_length = asp_word_length[fmt];



	if (mcbsp_word_length < 0)

		return mcbsp_word_length;



	switch (master) {

	case SND_SOC_DAIFMT_BP_FP:

		if (dev->ext_clk) {
@@ -483,8 +559,13 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream, 
	switch (master) {

	case SND_SOC_DAIFMT_BP_FP:

	case SND_SOC_DAIFMT_BP_FC:

		if (dev->tdm_slots > 0) {

			rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(dev->tdm_slots - 1);

			xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(dev->tdm_slots - 1);

		} else {

			rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(0);

			xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(0);

		}

		break;

	case SND_SOC_DAIFMT_BC_FC:

	case SND_SOC_DAIFMT_BC_FP:
@@ -609,19 +690,20 @@ static const struct snd_soc_dai_ops davinci_i2s_dai_ops = { 
	.hw_params	= davinci_i2s_hw_params,

	.set_fmt	= davinci_i2s_set_dai_fmt,

	.set_clkdiv	= davinci_i2s_dai_set_clkdiv,

	.set_tdm_slot   = davinci_i2s_set_tdm_slot,



};



static struct snd_soc_dai_driver davinci_i2s_dai = {

	.playback = {

		.channels_min = 2,

		.channels_max = 2,

		.channels_max = 128,

		.rates = DAVINCI_I2S_RATES,

		.formats = DAVINCI_I2S_FORMATS,

	},

	.capture = {

		.channels_min = 2,

		.channels_max = 2,

		.channels_max = 128,

		.rates = DAVINCI_I2S_RATES,

		.formats = DAVINCI_I2S_FORMATS,

	},