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: Bastien Curutchet bastien.curutchet@bootlin.com --- sound/soc/ti/davinci-i2s.c | 92 +++++++++++++++++++++++++++++++++++--- 1 file changed, 87 insertions(+), 5 deletions(-)
diff --git a/sound/soc/ti/davinci-i2s.c b/sound/soc/ti/davinci-i2s.c index a2c7c812ea50..f9a67c2bc2f5 100644 --- a/sound/soc/ti/davinci-i2s.c +++ b/sound/soc/ti/davinci-i2s.c @@ -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; @@ -383,7 +453,13 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream,
master = dev->fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK; fmt = params_format(params); - mcbsp_word_length = asp_word_length[fmt]; + 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: @@ -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: - rcr |= DAVINCI_MCBSP_RCR_RFRLEN1(0); - xcr |= DAVINCI_MCBSP_XCR_XFRLEN1(0); + 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, },