[RFC PATCH 3/3] ASoC: cpcap: add headphone jack plug detection support

[Carl Philipp Klemm]

Implements an interrupt handler that fires when a headphone
is inserted. A jack must be provided to the codec via
snd_soc_component_driver .set_jack

This patch currently also reports on "Headphones" pin. this correctly
causes a warning as this pin dose not exist, however reporting on any
other pin causes userspace (pulse audio) to not react to the change, im
not sure how pulseaudio is supposed to be configured to avoid this
deliemma "Headphones" apears to be hard-coded, please do lmk if someone
knows how to resolve this.

---
 sound/soc/codecs/cpcap.c | 104 +++++++++++++++++++++++++++++++++++----
 1 file changed, 94 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/cpcap.c b/sound/soc/codecs/cpcap.c
index 3c2bc98031b5..ed418ac75eca 100644
--- a/sound/soc/codecs/cpcap.c
+++ b/sound/soc/codecs/cpcap.c
@@ -15,6 +15,7 @@
 #include <sound/core.h>
 #include <sound/soc.h>
 #include <sound/tlv.h>
+#include <sound/jack.h>
 
 /* Register 512 CPCAP_REG_VAUDIOC --- Audio Regulator and Bias Voltage
*/ #define CPCAP_BIT_AUDIO_LOW_PWR           6
@@ -252,8 +253,14 @@ enum cpcap_dai {
 };
 
 struct cpcap_audio {
+	struct device *dev;
 	struct snd_soc_component *component;
 	struct regmap *regmap;
+	struct snd_soc_jack *hp_jack;
+
+	struct delayed_work jack_detect_work;
+
+	int hp_irq;
 
 	u16 vendor;
 
@@ -603,6 +610,21 @@ static int cpcap_input_left_mux_put_enum(struct
snd_kcontrol *kcontrol, return 0;
 }
 
+static struct snd_soc_jack_pin headset_jack_pins[] = {
+	{
+		.pin = "Headset Right Playback Route",
+		.mask = SND_JACK_HEADPHONE,
+	},
+	{
+		.pin = "Headset Left Playback Route",
+		.mask = SND_JACK_HEADPHONE,
+	},
+	{
+		.pin = "Headphones",
+		.mask = SND_JACK_HEADPHONE,
+	}
+};
+
 static const struct snd_kcontrol_new cpcap_input_left_mux =
 	SOC_DAPM_ENUM_EXT("Input Left", cpcap_input_left_mux_enum,
 			  cpcap_input_left_mux_get_enum,
@@ -1561,8 +1583,6 @@ static int cpcap_dai_mux(struct cpcap_audio
*cpcap, bool swap_dai_configuration) u16 voice_mask =
BIT(CPCAP_BIT_DIG_AUD_IN); int err;
 
-
-
 	if (!swap_dai_configuration) {
 		/* Codec on DAI0, HiFi on DAI1 */
 		voice_val = 0;
@@ -1586,6 +1606,44 @@ static int cpcap_dai_mux(struct cpcap_audio
*cpcap, bool swap_dai_configuration) return 0;
 }
 
+static irqreturn_t cpcap_hp_irq_thread(int irq, void *arg)
+{
+	struct cpcap_audio *cpcap = arg;
+	int val = -1;
+	bool plugged;
+
+	regmap_read(cpcap->regmap, CPCAP_REG_INTS1, &val);
+	plugged = val & (1<<9);
+
+	if (!cpcap->component) {
+		dev_warn(cpcap->dev, "%s called before component is
ready.", __func__);
+		return IRQ_HANDLED;
+	}
+
+	if (!cpcap->hp_jack) {
+		dev_warn(cpcap->dev, "%s called before jack is
ready.", __func__);
+		return IRQ_HANDLED;
+	}
+
+	snd_soc_jack_report(cpcap->hp_jack, plugged ? 0 :
SND_JACK_HEADPHONE, SND_JACK_HEADPHONE); +
+	return IRQ_HANDLED;
+}
+
+static int cpcap_set_jack_detect(struct snd_soc_component *component,
+	struct snd_soc_jack *hp_jack, void *data)
+{
+	struct cpcap_audio *cpcap =
snd_soc_component_get_drvdata(component); +
+	if (!cpcap->hp_jack) {
+		dev_info(cpcap->dev, "registering jack");
+		cpcap->hp_jack = hp_jack;
+		snd_soc_jack_add_pins(hp_jack,
ARRAY_SIZE(headset_jack_pins), headset_jack_pins);
+	}
+
+	return 0;
+}
+
 static int cpcap_audio_reset(struct snd_soc_component *component,
 			     bool swap_dai_configuration)
 {
@@ -1628,13 +1686,9 @@ static int cpcap_audio_reset(struct
snd_soc_component *component, 
 static int cpcap_soc_probe(struct snd_soc_component *component)
 {
-	struct cpcap_audio *cpcap;
+	struct cpcap_audio *cpcap =
snd_soc_component_get_drvdata(component); int err;
 
-	cpcap = devm_kzalloc(component->dev, sizeof(*cpcap),
GFP_KERNEL);
-	if (!cpcap)
-		return -ENOMEM;
-	snd_soc_component_set_drvdata(component, cpcap);
 	cpcap->component = component;
 
 	cpcap->regmap = dev_get_regmap(component->dev->parent, NULL);
@@ -1657,6 +1711,7 @@ static struct snd_soc_component_driver
soc_codec_dev_cpcap = { .num_dapm_widgets	=
ARRAY_SIZE(cpcap_dapm_widgets), .dapm_routes		= intercon,
 	.num_dapm_routes	= ARRAY_SIZE(intercon),
+	.set_jack = cpcap_set_jack_detect,
 	.idle_bias_on		= 1,
 	.use_pmdown_time	= 1,
 	.endianness		= 1,
@@ -1665,13 +1720,42 @@ static struct snd_soc_component_driver
soc_codec_dev_cpcap = { 
 static int cpcap_codec_probe(struct platform_device *pdev)
 {
-	struct device_node *codec_node =
-		of_get_child_by_name(pdev->dev.parent->of_node,
"audio-codec");
+	struct cpcap_audio *cpcap;
+	struct device_node *codec_node;
+	int ret;
 
+	codec_node = of_get_child_by_name(pdev->dev.parent->of_node,
"audio-codec"); pdev->dev.of_node = codec_node;
 
-	return devm_snd_soc_register_component(&pdev->dev,
&soc_codec_dev_cpcap,
+	cpcap = devm_kzalloc(&pdev->dev, sizeof(*cpcap), GFP_KERNEL);
+	if (!cpcap)
+		return -ENOMEM;
+	dev_set_drvdata(&pdev->dev, cpcap);
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
&soc_codec_dev_cpcap, cpcap_dai, ARRAY_SIZE(cpcap_dai));
+	if (ret < 0)
+		return ret;
+
+	cpcap->hp_irq = platform_get_irq_byname(pdev, "hpplugged");
+	if (cpcap->hp_irq < 0)
+		return -ENODEV;
+
+	cpcap->dev = &pdev->dev;
+
+	ret = devm_request_threaded_irq(&pdev->dev, cpcap->hp_irq,
NULL,
+					  cpcap_hp_irq_thread,
+					  IRQF_TRIGGER_RISING |
+					  IRQF_TRIGGER_FALLING |
+					  IRQF_ONESHOT,
+					  "cpcap-codec-headphone",
cpcap);
+	if (ret) {
+		dev_err(&pdev->dev, "could not get irq: %i\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
 }
 
 static struct platform_driver cpcap_codec_driver = {
-- 
2.34.1