[alsa-devel] [PATCH] ASoC: Fix maximum value for microphone gain

Fabio Estevam festevam at gmail.com
Sun Dec 23 18:41:19 CET 2012


From: Fabio Estevam <fabio.estevam at freescale.com>

sgtl5000 microphone gain only has 2 bits of resolution, so maximum value is 3.

>From Eric Nelson:
"We also found that for the microphones we have here (commodity PC boom mics) a 
default value of 2 for the gain gives the best results."

So change the default microphone gain as well.

Signed-off-by: Eric Nelson <eric.nelson at boundarydevices.com>
Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
 sound/soc/codecs/sgtl5000.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index cb1675c..92bbfec 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -401,7 +401,7 @@ static const struct snd_kcontrol_new sgtl5000_snd_controls[] = {
 			5, 1, 0),
 
 	SOC_SINGLE_TLV("Mic Volume", SGTL5000_CHIP_MIC_CTRL,
-			0, 4, 0, mic_gain_tlv),
+			0, 3, 0, mic_gain_tlv),
 };
 
 /* mute the codec used by alsa core */
@@ -1344,7 +1344,7 @@ static int sgtl5000_probe(struct snd_soc_codec *codec)
 			SGTL5000_HP_ZCD_EN |
 			SGTL5000_ADC_ZCD_EN);
 
-	snd_soc_write(codec, SGTL5000_CHIP_MIC_CTRL, 0);
+	snd_soc_write(codec, SGTL5000_CHIP_MIC_CTRL, 2);
 
 	/*
 	 * disable DAP
-- 
1.7.9.5



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