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@xxxxxxxxxxx>
---
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,
},
--
2.44.0
