Subject: [PATCH v4 7/9] ASoC: sun4i-i2s: Add multichannel functionality

From: [email-masked]
Date: Mon, 3 Jun 2019 19:47:33 +0200

From: Marcus Cooper <[email-masked]>

The i2s block can be used to pass PCM data over multiple channels
and is sometimes used for the audio side of an HDMI connection.

Signed-off-by: Marcus Cooper <[email-masked]>
---
 sound/soc/sunxi/sun4i-i2s.c | 121 +++++++++++++++++++-----------------
 1 file changed, 64 insertions(+), 57 deletions(-)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
index 75217fb52bfa..3549a87ed9e9 100644
--- a/sound/soc/sunxi/sun4i-i2s.c
+++ b/sound/soc/sunxi/sun4i-i2s.c
@@ -189,6 +189,7 @@ struct sun4i_i2s {
 
 	unsigned int	tdm_slots;
 	unsigned int	slot_width;
+	unsigned int	offset;
 };
 
 struct sun4i_i2s_clk_div {
@@ -358,56 +359,71 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
 	int lines;
 
 	channels = params_channels(params);
-	if ((channels > dai->driver->playback.channels_max) ||
-		(channels < dai->driver->playback.channels_min)) {
-		dev_err(dai->dev, "Unsupported number of channels: %d\n",
-			channels);
-		return -EINVAL;
-	}
-
-	lines = (channels + 1) / 2;
-
-	/* Enable the required output lines */
-	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
-			   SUN4I_I2S_CTRL_SDO_EN_MASK,
-			   SUN4I_I2S_CTRL_SDO_EN(lines));
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		if ((channels > dai->driver->playback.channels_max) ||
+			(channels < dai->driver->playback.channels_min)) {
+			dev_err(dai->dev, "Unsupported number of channels: %d\n",
+				channels);
+			return -EINVAL;
+		}
 
-	if (i2s->variant->is_h3_i2s_based) {
-		regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
-				   SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM_MASK,
-				   SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM(channels));
-		regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
-				   SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM_MASK,
-				   SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM(channels));
-	}
+		lines = (channels + 1) / 2;
 
-	/* Map the channels for playback and capture */
-	regmap_field_write(i2s->field_rxchanmap, 0x00003210);
-	regmap_field_write(i2s->field_txchanmap, 0x10);
-	if (i2s->variant->is_h3_i2s_based) {
-		if (channels > 2)
-			regmap_write(i2s->regmap,
-				     SUN8I_I2S_TX_CHAN_MAP_REG+4, 0x32);
-		if (channels > 4)
-			regmap_write(i2s->regmap,
-				     SUN8I_I2S_TX_CHAN_MAP_REG+8, 0x54);
-		if (channels > 6)
-			regmap_write(i2s->regmap,
-				     SUN8I_I2S_TX_CHAN_MAP_REG+12, 0x76);
+		/* Enable the required output lines */
+		regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+				   SUN4I_I2S_CTRL_SDO_EN_MASK,
+				   SUN4I_I2S_CTRL_SDO_EN(lines));
+
+		if (i2s->variant->is_h3_i2s_based)
+			regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
+					   SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM_MASK,
+					   SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM(channels));
+
+		regmap_field_write(i2s->field_txchanmap, 0x10);
+		/* Configure the channels */
+		regmap_field_write(i2s->field_txchansel, SUN4I_I2S_CHAN_SEL(2));
+
+		if (i2s->variant->is_h3_i2s_based) {
+			u32 chan_sel = SUN8I_I2S_TX_CHAN_OFFSET(i2s->offset) | 0x1;
+			regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,
+				     chan_sel | 0x30);
+
+			if (channels > 2) {
+				regmap_write(i2s->regmap,
+					     SUN8I_I2S_TX_CHAN_MAP_REG+4, 0x32);
+				regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG+4,
+					     chan_sel | 0x30);
+			}
+			if (channels > 4) {
+				regmap_write(i2s->regmap,
+					     SUN8I_I2S_TX_CHAN_MAP_REG+8, 0x54);
+				regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG+8,
+					     chan_sel | 0x30);
+			}
+			if (channels > 6) {
+				regmap_write(i2s->regmap,
+					     SUN8I_I2S_TX_CHAN_MAP_REG+12, 0x76);
+				regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG+12,
+					     chan_sel | 0x30);
+			}
+		}
+	} else {
+		/* Map the channels for capture */
+		regmap_field_write(i2s->field_rxchanmap, 0x00003210);
+		regmap_field_write(i2s->field_rxchansel,
+				   SUN4I_I2S_CHAN_SEL(params_channels(params)));
+
+		if (i2s->variant->is_h3_i2s_based) {
+			regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
+					   SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM_MASK,
+					   SUN8I_I2S_CHAN_CFG_RX_SLOT_NUM(channels));
+
+			regmap_update_bits(i2s->regmap, SUN8I_I2S_RX_CHAN_SEL_REG,
+					   SUN8I_I2S_TX_CHAN_OFFSET_MASK,
+					   SUN8I_I2S_TX_CHAN_OFFSET(i2s->offset));
+		}
 	}
 
-	/* Configure the channels */
-	regmap_field_write(i2s->field_txchansel,
-			   SUN4I_I2S_CHAN_SEL(params_channels(params)));
-
-	regmap_field_write(i2s->field_rxchansel,
-			   SUN4I_I2S_CHAN_SEL(params_channels(params)));
-
-	if (i2s->variant->is_h3_i2s_based)
-		regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,
-				   SUN8I_I2S_TX_CHAN_EN_MASK,
-				   SUN8I_I2S_TX_CHAN_EN(channels));
-
 	switch (params_physical_width(params)) {
 	case 16:
 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
@@ -445,7 +461,6 @@ static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 {
 	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 	u32 val;
-	u32 offset = 0;
 	u32 bclk_polarity = SUN4I_I2S_FMT0_POLARITY_NORMAL;
 	u32 lrclk_polarity = SUN4I_I2S_FMT0_POLARITY_NORMAL;
 
@@ -453,7 +468,7 @@ static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
 	case SND_SOC_DAIFMT_I2S:
 		val = SUN4I_I2S_FMT0_FMT_I2S;
-		offset = 1;
+		i2s->offset = 1;
 		break;
 	case SND_SOC_DAIFMT_LEFT_J:
 		val = SUN4I_I2S_FMT0_FMT_LEFT_J;
@@ -474,16 +489,8 @@ static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
 		 * i2s shares the same setting with the LJ format. Increment
 		 * val so that the bit to value to write is correct.
 		 */
-		if (offset > 0)
+		if (i2s->offset > 0)
 			val++;
-		/* blck offset determines whether i2s or LJ */
-		regmap_update_bits(i2s->regmap, SUN8I_I2S_TX_CHAN_SEL_REG,
-				   SUN8I_I2S_TX_CHAN_OFFSET_MASK,
-				   SUN8I_I2S_TX_CHAN_OFFSET(offset));
-
-		regmap_update_bits(i2s->regmap, SUN8I_I2S_RX_CHAN_SEL_REG,
-				   SUN8I_I2S_TX_CHAN_OFFSET_MASK,
-				   SUN8I_I2S_TX_CHAN_OFFSET(offset));
 	}
 
 	regmap_field_write(i2s->field_fmt_mode, val);
-- 
2.21.0

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