ASoC: cpcap: add headphone jack plug detection support

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

Signed-off-by: Carl Philipp Klemm <philipp@uvos.xyz>

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 +1606,45 @@ 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;
+	}
+
+	dev_info(cpcap->dev, "%s jack state: %i", __func__, plugged ? 0 : SND_JACK_HEADPHONE);
+	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 +1687,9 @@ 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 +1712,7 @@ 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,
@@ -1665,15 +1721,45 @@ 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;
+
 	if (!codec_node)
 		return -ENODEV;
 
-	pdev->dev.of_node = codec_node;
+	cpcap = devm_kzalloc(&pdev->dev, sizeof(*cpcap), GFP_KERNEL);
+	if (!cpcap)
+		return -ENOMEM;
+	dev_set_drvdata(&pdev->dev, cpcap);
 
-	return devm_snd_soc_register_component(&pdev->dev, &soc_codec_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 = {