ASoC: dwc: Add TDM mode support

Depending on hardware implementaion of DWC I2S controller may support
TDM mode if enabled in SoC at design time.
Unfortunately there is no way to detect TDM capability for DWC by
reading registers. Anyway, if such capability enabled, TDM mode
can be enabled and configured by dai-tdm-slot-* DT options.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Link: https://lore.kernel.org/r/20230622200031.120168-1-fido_max@inbox.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 62 insertions, 3 deletions

diff --git a/sound/soc/dwc/dwc-i2s.c b/sound/soc/dwc/dwc-i2s.c
index 97d652f0e84d..1f1ee14b04e6 100644
--- a/sound/soc/dwc/dwc-i2s.c
+++ b/sound/soc/dwc/dwc-i2s.c
@@ -183,7 +183,15 @@ static void i2s_start(struct dw_i2s_dev *dev,
 {
 	struct i2s_clk_config_data *config = &dev->config;
 
-	i2s_write_reg(dev->i2s_base, IER, 1);
+	u32 reg = IER_IEN;
+
+	if (dev->tdm_slots) {
+		reg |= (dev->tdm_slots - 1) << IER_TDM_SLOTS_SHIFT;
+		reg |= IER_INTF_TYPE;
+		reg |= dev->frame_offset << IER_FRAME_OFF_SHIFT;
+	}
+
+	i2s_write_reg(dev->i2s_base, IER, reg);
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		i2s_write_reg(dev->i2s_base, ITER, 1);
@@ -233,13 +241,15 @@ static void dw_i2s_config(struct dw_i2s_dev *dev, int stream)
 				      dev->xfer_resolution);
 			i2s_write_reg(dev->i2s_base, TFCR(ch_reg),
 				      dev->fifo_th - 1);
-			i2s_write_reg(dev->i2s_base, TER(ch_reg), 1);
+			i2s_write_reg(dev->i2s_base, TER(ch_reg), TER_TXCHEN |
+				      dev->tdm_mask << TER_TXSLOT_SHIFT);
 		} else {
 			i2s_write_reg(dev->i2s_base, RCR(ch_reg),
 				      dev->xfer_resolution);
 			i2s_write_reg(dev->i2s_base, RFCR(ch_reg),
 				      dev->fifo_th - 1);
-			i2s_write_reg(dev->i2s_base, RER(ch_reg), 1);
+			i2s_write_reg(dev->i2s_base, RER(ch_reg), RER_RXCHEN |
+				      dev->tdm_mask << RER_RXSLOT_SHIFT);
 		}
 
 	}
@@ -276,6 +286,9 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
+	if (dev->tdm_slots)
+		config->data_width = 32;
+
 	config->chan_nr = params_channels(params);
 
 	switch (config->chan_nr) {
@@ -384,14 +397,58 @@ static int dw_i2s_set_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
 		ret = -EINVAL;
 		break;
 	}
+
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+	case SND_SOC_DAIFMT_LEFT_J:
+	case SND_SOC_DAIFMT_RIGHT_J:
+		break;
+	case SND_SOC_DAIFMT_DSP_A:
+		dev->frame_offset = 1;
+		break;
+	case SND_SOC_DAIFMT_DSP_B:
+		dev->frame_offset = 0;
+		break;
+	default:
+		dev_err(dev->dev, "DAI format unsupported");
+		return -EINVAL;
+	}
+
 	return ret;
 }
 
+static int dw_i2s_set_tdm_slot(struct snd_soc_dai *cpu_dai,	unsigned int tx_mask,
+			   unsigned int rx_mask, int slots, int slot_width)
+{
+	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
+
+	if (slot_width != 32)
+		return -EINVAL;
+
+	if (slots < 0 || slots > 16)
+		return -EINVAL;
+
+	if (rx_mask != tx_mask)
+		return -EINVAL;
+
+	if (!rx_mask)
+		return -EINVAL;
+
+	dev->tdm_slots = slots;
+	dev->tdm_mask = rx_mask;
+
+	dev->l_reg = RSLOT_TSLOT(ffs(rx_mask) - 1);
+	dev->r_reg = RSLOT_TSLOT(fls(rx_mask) - 1);
+
+	return 0;
+}
+
 static const struct snd_soc_dai_ops dw_i2s_dai_ops = {
 	.hw_params	= dw_i2s_hw_params,
 	.prepare	= dw_i2s_prepare,
 	.trigger	= dw_i2s_trigger,
 	.set_fmt	= dw_i2s_set_fmt,
+	.set_tdm_slot	= dw_i2s_set_tdm_slot,
 };
 
 #ifdef CONFIG_PM
@@ -726,6 +783,8 @@ static int dw_i2s_probe(struct platform_device *pdev)
 		if (irq >= 0) {
 			ret = dw_pcm_register(pdev);
 			dev->use_pio = true;
+			dev->l_reg = LRBR_LTHR(0);
+			dev->r_reg = RRBR_RTHR(0);
 		} else {
 			ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL,
 					0);