ASoC: ams-delta: Take control over audio mute GPIO pins

Since commit 1137ceee76ba ("ARM: OMAP1: ams-delta: Don't request unused
GPIOs"), on-board audio has appeared muted.  It has been discovered that
believed to be unused GPIO pins "hookflash1" and "hookflash2" need to be
set low for audible sound in handsfree and handset mode respectively.

According to Amstrad E3 wiki, the purpose of both pins hasn't been
clearly identified.  Original Amstrad software used to produce a high
pulse on them when the phone was taken off hook or recall was pressed.
With the current findings, we can assume the pins provide a kind of
audio mute function, separately for handset and handsfree operation
modes.

Commit 2afdb4c41d78 ("ARM: OMAP1: ams-delta: Fix audio permanently
muted") attempted to fix the issue temporarily by hogging the GPIO pin
"hookflash1" renamed to "audio_mute", however the fix occurred
incomplete as it restored audible sound only for handsfree mode.

Stop hogging that pin, rename the pins to "handsfree_mute" and
"handset_mute" respectively and implement appropriate DAPM event
callbacks for "Speaker" and "Earpiece" DAPM widgets.

Fixes: 1137ceee76ba ("ARM: OMAP1: ams-delta: Don't request unused GPIOs")
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20190907111650.15440-1-jmkrzyszt@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 29 insertions, 2 deletions

diff --git a/sound/soc/ti/ams-delta.c b/sound/soc/ti/ams-delta.c
index dee8fc70a64f..8e2fb81ad05c 100644
--- a/sound/soc/ti/ams-delta.c
+++ b/sound/soc/ti/ams-delta.c
@@ -23,14 +23,31 @@
 #include "omap-mcbsp.h"
 #include "../codecs/cx20442.h"
 
+static struct gpio_desc *handset_mute;
+static struct gpio_desc *handsfree_mute;
+
+static int ams_delta_event_handset(struct snd_soc_dapm_widget *w,
+				   struct snd_kcontrol *k, int event)
+{
+	gpiod_set_value_cansleep(handset_mute, !SND_SOC_DAPM_EVENT_ON(event));
+	return 0;
+}
+
+static int ams_delta_event_handsfree(struct snd_soc_dapm_widget *w,
+				     struct snd_kcontrol *k, int event)
+{
+	gpiod_set_value_cansleep(handsfree_mute, !SND_SOC_DAPM_EVENT_ON(event));
+	return 0;
+}
+
 /* Board specific DAPM widgets */
 static const struct snd_soc_dapm_widget ams_delta_dapm_widgets[] = {
 	/* Handset */
 	SND_SOC_DAPM_MIC("Mouthpiece", NULL),
-	SND_SOC_DAPM_HP("Earpiece", NULL),
+	SND_SOC_DAPM_HP("Earpiece", ams_delta_event_handset),
 	/* Handsfree/Speakerphone */
 	SND_SOC_DAPM_MIC("Microphone", NULL),
-	SND_SOC_DAPM_SPK("Speaker", NULL),
+	SND_SOC_DAPM_SPK("Speaker", ams_delta_event_handsfree),
 };
 
 /* How they are connected to codec pins */
@@ -542,6 +559,16 @@ static int ams_delta_probe(struct platform_device *pdev)
 
 	card->dev = &pdev->dev;
 
+	handset_mute = devm_gpiod_get(card->dev, "handset_mute",
+				      GPIOD_OUT_HIGH);
+	if (IS_ERR(handset_mute))
+		return PTR_ERR(handset_mute);
+
+	handsfree_mute = devm_gpiod_get(card->dev, "handsfree_mute",
+					GPIOD_OUT_HIGH);
+	if (IS_ERR(handsfree_mute))
+		return PTR_ERR(handsfree_mute);
+
 	ret = snd_soc_register_card(card);
 	if (ret) {
 		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);