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 capture.channels_max is updated from 2 to 128. 128 is the maximum frame length when using single-phase frame. playback.channels_max has not been updated as I could not test TDM on playbacks with my hardware.
This was tested on platform designed off of DAVINCI/OMAP_L138 with BP_FC format so this is only supported format for TDM yet. A check is done in davinci_i2s_set_dai_fmt() to prevent TDM to be used with other formats
Signed-off-by: Bastien Curutchet bastien.curutchet@bootlin.com --- sound/soc/ti/davinci-i2s.c | 81 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 77 insertions(+), 4 deletions(-)
diff --git a/sound/soc/ti/davinci-i2s.c b/sound/soc/ti/davinci-i2s.c index f4514d4dff07..4adaed010700 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 +216,57 @@ 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, "%s - slots %d, slot_width %d\n", __func__, 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 (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, @@ -228,6 +282,13 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai, DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);
dev->fmt = fmt; + + if ((dev->tdm_slots || dev->slot_width) && + ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) != SND_SOC_DAIFMT_BP_FC)) { + dev_err(dev->dev, "TDM is only supported for BP_FC format\n"); + return -EINVAL; + } + /* set master/slave audio interface */ switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) { case SND_SOC_DAIFMT_BP_FP: @@ -383,7 +444,13 @@ 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 +550,13 @@ 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: @@ -609,6 +681,7 @@ 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,
};
@@ -621,7 +694,7 @@ static struct snd_soc_dai_driver davinci_i2s_dai = { }, .capture = { .channels_min = 2, - .channels_max = 2, + .channels_max = 128, .rates = DAVINCI_I2S_RATES, .formats = DAVINCI_I2S_FORMATS, },