On 15/03/2024 13:27, Bastien Curutchet wrote: > 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@xxxxxxxxxxx> > --- > 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); The __func__ can be ommited, it is better to leave it for dynamic debugging by adding "dyndbg=+pmf" module parameter if needed. > + > + 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; This is only a restriction for RX? > + } > + > + 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; I think this is not a valid statement, Fsync can be generated internally or coming from external source in TDM mode also. > + } > + > /* 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, > }, -- Péter