[alsa-devel] [PATCH v3 6/9] ASoC: sun4i-i2s: Add multi-lane functionality

[codekipper at gmail.com]

From: Marcus Cooper <codekipper at gmail.com>

The i2s block supports multi-lane i2s output however this functionality
is only possible in earlier SoCs where the pins are exposed and for
the i2s block used for HDMI audio on the later SoCs.

To enable this functionality, an optional property has been added to
the bindings.

Signed-off-by: Marcus Cooper <codekipper at gmail.com>
---
 sound/soc/sunxi/sun4i-i2s.c | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
index b31f84787218..e85789d84c0c 100644
--- a/sound/soc/sunxi/sun4i-i2s.c
+++ b/sound/soc/sunxi/sun4i-i2s.c
@@ -27,7 +27,7 @@
 
 #define SUN4I_I2S_CTRL_REG		0x00
 #define SUN4I_I2S_CTRL_SDO_EN_MASK		GENMASK(11, 8)
-#define SUN4I_I2S_CTRL_SDO_EN(sdo)			BIT(8 + (sdo))
+#define SUN4I_I2S_CTRL_SDO_EN(lines)		(((1 << lines) - 1) << 8)
 #define SUN4I_I2S_CTRL_MODE_MASK		BIT(5)
 #define SUN4I_I2S_CTRL_MODE_SLAVE			(1 << 5)
 #define SUN4I_I2S_CTRL_MODE_MASTER			(0 << 5)
@@ -394,14 +394,23 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
 	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 	int sr, wss, channels;
 	u32 width;
+	int lines;
 
 	channels = params_channels(params);
-	if (channels != 2) {
+	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 (i2s->variant->has_chcfg) {
 		regmap_update_bits(i2s->regmap, SUN8I_I2S_CHAN_CFG_REG,
 				   SUN8I_I2S_CHAN_CFG_TX_SLOT_NUM_MASK,
@@ -412,8 +421,19 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
 	}
 
 	/* Map the channels for playback and capture */
-	regmap_field_write(i2s->field_txchanmap, 0x76543210);
 	regmap_field_write(i2s->field_rxchanmap, 0x00003210);
+	regmap_field_write(i2s->field_txchanmap, 0x10);
+	if (i2s->variant->has_chsel_tx_chen) {
+		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);
+	}
 
 	/* Configure the channels */
 	regmap_field_write(i2s->field_txchansel,
@@ -1094,9 +1114,10 @@ static int sun4i_i2s_init_regmap_fields(struct device *dev,
 static int sun4i_i2s_probe(struct platform_device *pdev)
 {
 	struct sun4i_i2s *i2s;
+	struct snd_soc_dai_driver *soc_dai;
 	struct resource *res;
 	void __iomem *regs;
-	int irq, ret;
+	int irq, ret, val;
 
 	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
 	if (!i2s)
@@ -1175,6 +1196,12 @@ static int sun4i_i2s_probe(struct platform_device *pdev)
 		soc_dai->capture.formats = SUN8I_FORMATS;
 	}
 
+	if (!of_property_read_u32(pdev->dev.of_node,
+				  "allwinner,playback-channels", &val)) {
+		if (val >= 2 && val <= 8)
+			soc_dai->playback.channels_max = val;
+	}
+
 	pm_runtime_enable(&pdev->dev);
 	if (!pm_runtime_enabled(&pdev->dev)) {
 		ret = sun4i_i2s_runtime_resume(&pdev->dev);
@@ -1184,7 +1211,7 @@ static int sun4i_i2s_probe(struct platform_device *pdev)
 
 	ret = devm_snd_soc_register_component(&pdev->dev,
 					      &sun4i_i2s_component,
-					      &sun4i_i2s_dai, 1);
+					      soc_dai, 1);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not register DAI\n");
 		goto err_suspend;
-- 
2.20.1