[alsa-devel] [PATCH v2 1/2] ASoC: tlv320aic32x4: Fix problem with first capture.
javier.martin at vista-silicon.com
Wed Oct 31 11:53:33 CET 2012
In its previous status, the first capture didn't work properly;
nothing was actually recorded from the microphone. This
behaviour was observed using a Visstrim M10 board.
In order to solve this BUG a workaround has been added that,
during the initialization process of the codec, powers on and
off the ADC.
The issue seems related to a HW BUG or some behavior that
is not documented in the datasheet.
Signed-off-by: Javier Martin <javier.martin at vista-silicon.com>
Changes since v1:
- Use a subject line according to the ASoC subsystem.
sound/soc/codecs/tlv320aic32x4.c | 10 ++++++++++
sound/soc/codecs/tlv320aic32x4.h | 3 +++
2 files changed, 13 insertions(+)
diff --git a/sound/soc/codecs/tlv320aic32x4.c b/sound/soc/codecs/tlv320aic32x4.c
index b0a73d3..aad92f9 100644
@@ -675,6 +675,16 @@ static int aic32x4_probe(struct snd_soc_codec *codec)
+ * Workaround: for an unknown reason, the ADC needs to be powered up
+ * and down for the first capture to work properly. It seems related to
+ * a HW BUG or some kind of behavior not documented in the datasheet.
+ tmp_reg = snd_soc_read(codec, AIC32X4_ADCSETUP);
+ snd_soc_write(codec, AIC32X4_ADCSETUP, tmp_reg |
+ AIC32X4_LADC_EN | AIC32X4_RADC_EN);
+ snd_soc_write(codec, AIC32X4_ADCSETUP, tmp_reg);
diff --git a/sound/soc/codecs/tlv320aic32x4.h b/sound/soc/codecs/tlv320aic32x4.h
index aae2b24..3577422 100644
@@ -94,6 +94,9 @@
#define AIC32X4_WORD_LEN_24BITS 0x02
#define AIC32X4_WORD_LEN_32BITS 0x03
+#define AIC32X4_LADC_EN (1 << 7)
+#define AIC32X4_RADC_EN (1 << 6)
#define AIC32X4_I2S_MODE 0x00
#define AIC32X4_DSP_MODE 0x01
#define AIC32X4_RIGHT_JUSTIFIED_MODE 0x02
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