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[02/10] ASoC: es8316: Add DAC mono mix switch mixer control

Message ID 20190103134535.13861-3-hdegoede@redhat.com (mailing list archive)
State Accepted
Commit 24b53f17a3f24967b8b523243f9f7fc361427119
Headers show
Series ASoC: bytcht-es8316 fixes and improvements | expand

Commit Message

Hans de Goede Jan. 3, 2019, 1:45 p.m. UTC
Export the DAC functionality to mix left + right together and then output
the same (mixed) signal on both outputs.

Various (x86) tablets with an ES8316 codec use a single speaker
connected between the headhpone LOUT and ROUT pins, expecting the output
to be in a mono differential mode. Presumably this is done to use the
power of both the left and right outputs to allow the speaker to be
louder.

The ES8316 codec does not have a differential output mode, but we can
emulate this by making both channels output the same through the mono mix
switch, combined with setting the Playback Polarity control to "R Invert",
which applias a 180 degrees phase inversion to the right channel.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 sound/soc/codecs/es8316.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/sound/soc/codecs/es8316.c b/sound/soc/codecs/es8316.c
index 26413851e434..98464ba1046c 100644
--- a/sound/soc/codecs/es8316.c
+++ b/sound/soc/codecs/es8316.c
@@ -101,6 +101,7 @@  static const struct snd_kcontrol_new es8316_snd_controls[] = {
 	SOC_SINGLE("DAC Notch Filter Switch", ES8316_DAC_SET2, 6, 1, 0),
 	SOC_SINGLE("DAC Double Fs Switch", ES8316_DAC_SET2, 7, 1, 0),
 	SOC_SINGLE("DAC Stereo Enhancement", ES8316_DAC_SET3, 0, 7, 0),
+	SOC_SINGLE("DAC Mono Mix Switch", ES8316_DAC_SET3, 3, 1, 0),
 
 	SOC_ENUM("Capture Polarity", adcpol),
 	SOC_SINGLE("Mic Boost Switch", ES8316_ADC_D2SEPGA, 0, 1, 0),