[PATCH v1 1/4] ASoC: codecs: tfa989x: Add switch to allow disabling amplifier

From: Vincent Knecht
Date: Sun Oct 24 2021 - 05:19:47 EST


From: Stephan Gerhold <stephan@xxxxxxxxxxx>

In some configurations it may be necessary to explicitly disable
the amplifier with an ALSA mixer. An example for this is a stereo
setup with two TFA989X. If only one of them should be used (e.g.
to use it as an earpiece) the other one must be explicitly disabled.

Add a virtual "Amp Switch" to implement that. There is no register
for this (SND_SOC_NOPM) so it only prevents DAPM from activating
the amplifier. Also it is inverted (= enabled by default) for
compatibility with devices that do not need this functionality.

Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
Signed-off-by: Vincent Knecht <vincent.knecht@xxxxxxxxxx>
---
sound/soc/codecs/tfa989x.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/tfa989x.c b/sound/soc/codecs/tfa989x.c
index 643b45188b6f..1ae47d4f1ca7 100644
--- a/sound/soc/codecs/tfa989x.c
+++ b/sound/soc/codecs/tfa989x.c
@@ -77,13 +77,16 @@ static const struct regmap_config tfa989x_regmap = {

static const char * const chsa_text[] = { "Left", "Right", /* "DSP" */ };
static SOC_ENUM_SINGLE_DECL(chsa_enum, TFA989X_I2SREG, TFA989X_I2SREG_CHSA, chsa_text);
-static const struct snd_kcontrol_new chsa_mux = SOC_DAPM_ENUM("Amp Input", chsa_enum);
+static const struct snd_kcontrol_new
+ chsa_mux = SOC_DAPM_ENUM("Amp Input", chsa_enum),
+ amp_switch = SOC_DAPM_SINGLE("Switch", SND_SOC_NOPM, 0, 1, 1);

static const struct snd_soc_dapm_widget tfa989x_dapm_widgets[] = {
SND_SOC_DAPM_OUTPUT("OUT"),
SND_SOC_DAPM_SUPPLY("POWER", TFA989X_SYS_CTRL, TFA989X_SYS_CTRL_PWDN, 1, NULL, 0),
SND_SOC_DAPM_OUT_DRV("AMPE", TFA989X_SYS_CTRL, TFA989X_SYS_CTRL_AMPE, 0, NULL, 0),

+ SND_SOC_DAPM_SWITCH("Amp", SND_SOC_NOPM, 0, 0, &amp_switch),
SND_SOC_DAPM_MUX("Amp Input", SND_SOC_NOPM, 0, 0, &chsa_mux),
SND_SOC_DAPM_AIF_IN("AIFINL", "HiFi Playback", 0, SND_SOC_NOPM, 0, 0),
SND_SOC_DAPM_AIF_IN("AIFINR", "HiFi Playback", 1, SND_SOC_NOPM, 0, 0),
@@ -92,7 +95,8 @@ static const struct snd_soc_dapm_widget tfa989x_dapm_widgets[] = {
static const struct snd_soc_dapm_route tfa989x_dapm_routes[] = {
{"OUT", NULL, "AMPE"},
{"AMPE", NULL, "POWER"},
- {"AMPE", NULL, "Amp Input"},
+ {"AMPE", NULL, "Amp"},
+ {"Amp", "Switch", "Amp Input"},
{"Amp Input", "Left", "AIFINL"},
{"Amp Input", "Right", "AIFINR"},
};
--
2.31.1