ASoC: uniphier: add digital output volume for UniPhier sound system

This patch adds controllers for digital volume of PCM output. Volume
effects simply linear, not dB scale as follows:
  Gained PCM = Original * 0x4000 / Volume

The value range of volume is from 0x0001 to 0xffff. 0x0000 works as
mute. Initial value is 0x4000 (+0dB).

Signed-off-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/sound/soc/uniphier/aio-core.c b/sound/soc/uniphier/aio-core.c
index e37b80921abb..638cb3fc5f7b 100644
--- a/sound/soc/uniphier/aio-core.c
+++ b/sound/soc/uniphier/aio-core.c
@@ -660,6 +660,64 @@ void aio_port_set_enable(struct uniphier_aio_sub *sub, int enable)
 }
 
 /**
+ * aio_port_get_volume - get volume of AIO port block
+ * @sub: the AIO substream pointer
+ *
+ * Return: current volume, range is 0x0000 - 0xffff
+ */
+int aio_port_get_volume(struct uniphier_aio_sub *sub)
+{
+	struct regmap *r = sub->aio->chip->regmap;
+	u32 v;
+
+	regmap_read(r, OPORTMXTYVOLGAINSTATUS(sub->swm->oport.map, 0), &v);
+
+	return FIELD_GET(OPORTMXTYVOLGAINSTATUS_CUR_MASK, v);
+}
+
+/**
+ * aio_port_set_volume - set volume of AIO port block
+ * @sub: the AIO substream pointer
+ * @vol: target volume, range is 0x0000 - 0xffff.
+ *
+ * Change digital volume and perfome fade-out/fade-in effect for specified
+ * output slot of port. Gained PCM value can calculate as the following:
+ *   Gained = Original * vol / 0x4000
+ */
+void aio_port_set_volume(struct uniphier_aio_sub *sub, int vol)
+{
+	struct regmap *r = sub->aio->chip->regmap;
+	int oport_map = sub->swm->oport.map;
+	int cur, diff, slope = 0, fs;
+
+	if (sub->swm->dir == PORT_DIR_INPUT)
+		return;
+
+	cur = aio_port_get_volume(sub);
+	diff = abs(vol - cur);
+	fs = params_rate(&sub->params);
+	if (fs)
+		slope = diff / AUD_VOL_FADE_TIME * 1000 / fs;
+	slope = max(1, slope);
+
+	regmap_update_bits(r, OPORTMXTYVOLPARA1(oport_map, 0),
+			   OPORTMXTYVOLPARA1_SLOPEU_MASK, slope << 16);
+	regmap_update_bits(r, OPORTMXTYVOLPARA2(oport_map, 0),
+			   OPORTMXTYVOLPARA2_TARGET_MASK, vol);
+
+	if (cur < vol)
+		regmap_update_bits(r, OPORTMXTYVOLPARA2(oport_map, 0),
+				   OPORTMXTYVOLPARA2_FADE_MASK,
+				   OPORTMXTYVOLPARA2_FADE_FADEIN);
+	else
+		regmap_update_bits(r, OPORTMXTYVOLPARA2(oport_map, 0),
+				   OPORTMXTYVOLPARA2_FADE_MASK,
+				   OPORTMXTYVOLPARA2_FADE_FADEOUT);
+
+	regmap_write(r, AOUTFADECTR0, BIT(oport_map));
+}
+
+/**
  * aio_if_set_param - set parameters of AIO DMA I/F block
  * @sub: the AIO substream pointer
  * @pass_through: Zero if sound data is LPCM, otherwise if data is not LPCM.