[alsa-devel] [PATCH 8/8] ASoC: Disable automatic volume control in the CS4270 sound driver

[Mark Brown]

From: Timur Tabi <timur at freescale.com>

Disable the automatic volume control feature of the CS4270 audio codec.  This
feature, which is enabled by default, causes volume change commands to be
delayed.  Sometimes the volume change happens after playback is started.

Signed-off-by: Timur Tabi <timur at freescale.com>
Signed-off-by: Mark Brown <broonie at opensource.wolfsonmicro.com>
---
 sound/soc/codecs/cs4270.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c
index 0bbd945..0ff476d 100644
--- a/sound/soc/codecs/cs4270.c
+++ b/sound/soc/codecs/cs4270.c
@@ -450,6 +450,19 @@ static int cs4270_hw_params(struct snd_pcm_substream *substream,
 		return ret;
 	}
 
+	/* Disable automatic volume control.  It's enabled by default, and
+	 * it causes volume change commands to be delayed, sometimes until
+	 * after playback has started.
+	 */
+
+	reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
+	reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
+	ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
+	if (ret < 0) {
+		printk(KERN_ERR "I2C write failed\n");
+		return ret;
+	}
+
 	/* Thaw and power-up the codec */
 
 	ret = snd_soc_write(codec, CS4270_PWRCTL, 0);
-- 
1.5.6.5