[PATCH 3/3] ASoC: sun4i-i2s: Add regmap field to sign extend sample

[codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org]

From: Marcus Cooper <codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

On the newer SoCs this is set by default to transfer a 0 after
each sample in each slot. Add the regmap field to configure this
and set it so that it pads the sample with 0s.

Signed-off-by: Marcus Cooper <codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 sound/soc/sunxi/sun4i-i2s.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
index 626679057d0f..9fda1240b717 100644
--- a/sound/soc/sunxi/sun4i-i2s.c
+++ b/sound/soc/sunxi/sun4i-i2s.c
@@ -139,6 +139,7 @@
  * @field_fmt_bclk: regmap field to set clk polarity.
  * @field_fmt_lrclk: regmap field to set frame polarity.
  * @field_fmt_mode: regmap field to set the operational mode.
+ * @field_fmt_sext: regmap field to set the sign extension.
  * @field_txchanmap: location of the tx channel mapping register.
  * @field_rxchanmap: location of the rx channel mapping register.
  * @field_txchansel: location of the tx channel select bit fields.
@@ -164,6 +165,7 @@ struct sun4i_i2s_quirks {
 	struct reg_field		field_fmt_bclk;
 	struct reg_field		field_fmt_lrclk;
 	struct reg_field		field_fmt_mode;
+	struct reg_field		field_fmt_sext;
 	struct reg_field		field_txchanmap;
 	struct reg_field		field_rxchanmap;
 	struct reg_field		field_txchansel;
@@ -188,6 +190,7 @@ struct sun4i_i2s {
 	struct regmap_field	*field_fmt_bclk;
 	struct regmap_field	*field_fmt_lrclk;
 	struct regmap_field	*field_fmt_mode;
+	struct regmap_field	*field_fmt_sext;
 	struct regmap_field	*field_txchanmap;
 	struct regmap_field	*field_rxchanmap;
 	struct regmap_field	*field_txchansel;
@@ -358,6 +361,9 @@ static int sun4i_i2s_set_clk_rate(struct snd_soc_dai *dai,
 				   SUN8I_I2S_FMT0_LRCK_PERIOD_MASK,
 				   SUN8I_I2S_FMT0_LRCK_PERIOD(word_size));
 
+	/* Set sign extension to pad out LSB with 0 */
+	regmap_field_write(i2s->field_fmt_sext, 0);
+
 	return 0;
 }
 
@@ -929,6 +935,7 @@ static const struct sun4i_i2s_quirks sun4i_a10_i2s_quirks = {
 	.field_fmt_lrclk	= REG_FIELD(SUN4I_I2S_FMT0_REG, 7, 7),
 	.has_slave_select_bit	= true,
 	.field_fmt_mode		= REG_FIELD(SUN4I_I2S_FMT0_REG, 0, 1),
+	.field_fmt_sext		= REG_FIELD(SUN4I_I2S_FMT1_REG, 8, 8),
 	.field_txchanmap	= REG_FIELD(SUN4I_I2S_TX_CHAN_MAP_REG, 0, 31),
 	.field_rxchanmap	= REG_FIELD(SUN4I_I2S_RX_CHAN_MAP_REG, 0, 31),
 	.field_txchansel	= REG_FIELD(SUN4I_I2S_TX_CHAN_SEL_REG, 0, 2),
@@ -946,6 +953,7 @@ static const struct sun4i_i2s_quirks sun6i_a31_i2s_quirks = {
 	.field_fmt_lrclk	= REG_FIELD(SUN4I_I2S_FMT0_REG, 7, 7),
 	.has_slave_select_bit	= true,
 	.field_fmt_mode		= REG_FIELD(SUN4I_I2S_FMT0_REG, 0, 1),
+	.field_fmt_sext		= REG_FIELD(SUN4I_I2S_FMT1_REG, 8, 8),
 	.field_txchanmap	= REG_FIELD(SUN4I_I2S_TX_CHAN_MAP_REG, 0, 31),
 	.field_rxchanmap	= REG_FIELD(SUN4I_I2S_RX_CHAN_MAP_REG, 0, 31),
 	.field_txchansel	= REG_FIELD(SUN4I_I2S_TX_CHAN_SEL_REG, 0, 2),
@@ -986,6 +994,7 @@ static const struct sun4i_i2s_quirks sun8i_h3_i2s_quirks = {
 	.field_fmt_bclk		= REG_FIELD(SUN4I_I2S_FMT0_REG, 7, 7),
 	.field_fmt_lrclk	= REG_FIELD(SUN4I_I2S_FMT0_REG, 19, 19),
 	.field_fmt_mode		= REG_FIELD(SUN4I_I2S_CTRL_REG, 4, 5),
+	.field_fmt_sext		= REG_FIELD(SUN4I_I2S_FMT1_REG, 4, 5),
 	.field_txchanmap	= REG_FIELD(SUN8I_I2S_TX_CHAN_MAP_REG, 0, 31),
 	.field_rxchanmap	= REG_FIELD(SUN8I_I2S_RX_CHAN_MAP_REG, 0, 31),
 	.field_txchansel	= REG_FIELD(SUN8I_I2S_TX_CHAN_SEL_REG, 0, 2),
@@ -1031,6 +1040,12 @@ static int sun4i_i2s_init_regmap_fields(struct device *dev,
 	if (IS_ERR(i2s->field_fmt_mode))
 		return PTR_ERR(i2s->field_fmt_mode);
 
+	i2s->field_fmt_sext =
+			devm_regmap_field_alloc(dev, i2s->regmap,
+						i2s->variant->field_fmt_sext);
+	if (IS_ERR(i2s->field_fmt_sext))
+		return PTR_ERR(i2s->field_fmt_sext);
+
 	i2s->field_txchanmap =
 			devm_regmap_field_alloc(dev, i2s->regmap,
 						i2s->variant->field_txchanmap);
-- 
2.16.0