[PATCH 1/1] ASoC: sgtl5000: enable VAG_POWER for LINE_IN

From: Dong Aisheng <redacted>

LINE_IN also needs VAG_POWER on or we may hear noise when directly
route LINE_IN to Headphone Mux.
Tested on imx28evk.

Signed-off-by: Dong Aisheng <redacted>
---
 sound/soc/codecs/sgtl5000.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 5c54b6f..df2f99d 100644
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c

@@ -239,6 +239,7 @@ static const struct snd_soc_dapm_route sgtl5000_dapm_routes[] = {
 	{"Headphone Mux", "DAC", "DAC"},	/* dac --> hp_mux */
 	{"LO", NULL, "DAC"},			/* dac --> line_out */
 
+	{"LINE_IN", NULL, "VAG_POWER"},
 	{"Headphone Mux", "LINE_IN", "LINE_IN"},/* line_in --> hp_mux */
 	{"HP", NULL, "Headphone Mux"},		/* hp_mux --> hp */
 

-- 
1.7.0.4

On Fri, Jul 27, 2012 at 07:18:42PM +0800, Dong Aisheng wrote:

From: Dong Aisheng <redacted>

LINE_IN also needs VAG_POWER on or we may hear noise when directly
route LINE_IN to Headphone Mux.

The following is what I see from sgtl5000 data sheet about VAG_POWER.

  VAG is the internal voltage reference for the ADC and DAC.

Are you seeing any info that requires VAG_POWER in route of LINE_IN to
Headphone Mux?  Or it's only a result from your testing?

Does it also fix the noise issue you mentioned with normal recording
(LINE_IN to ADC) before?

Regards,
Shawn

On Fri, Jul 27, 2012 at 07:18:42PM +0800, Dong Aisheng wrote:

From: Dong Aisheng <redacted>

LINE_IN also needs VAG_POWER on or we may hear noise when directly
route LINE_IN to Headphone Mux.
Tested on imx28evk.

Applied, thanks.

On Sat, Jul 28, 2012 at 10:39:59PM +0800, Shawn Guo wrote:

On Fri, Jul 27, 2012 at 07:18:42PM +0800, Dong Aisheng wrote:

quoted

LINE_IN also needs VAG_POWER on or we may hear noise when directly
route LINE_IN to Headphone Mux.

The following is what I see from sgtl5000 data sheet about VAG_POWER.

  VAG is the internal voltage reference for the ADC and DAC.

Are you seeing any info that requires VAG_POWER in route of LINE_IN to
Headphone Mux?  Or it's only a result from your testing?

Given the name I rather suspect that's a datasheet error and the same
reference is used by other bits of the chip.  Just guessing, though.

On Sat, Jul 28, 2012 at 10:39:59PM +0800, Shawn Guo wrote:

On Fri, Jul 27, 2012 at 07:18:42PM +0800, Dong Aisheng wrote:

quoted

From: Dong Aisheng <redacted>

LINE_IN also needs VAG_POWER on or we may hear noise when directly
route LINE_IN to Headphone Mux.

The following is what I see from sgtl5000 data sheet about VAG_POWER.

  VAG is the internal voltage reference for the ADC and DAC.

Are you seeing any info that requires VAG_POWER in route of LINE_IN to
Headphone Mux?  Or it's only a result from your testing?

No, it's from the test result.
Maybe i should have added a FIXME for this.

Does it also fix the noise issue you mentioned with normal recording
(LINE_IN to ADC) before?

ADC also needs VAG power which already fixed by:
commit f0cdcf3 (ASoC: sgtl5000: Enable VAG when DAC/ADC up)
This patch is only for direct LINE_IN to Headphone Mux.

Regards
Dong Aisheng