[PATCH] ASoC: cs42l42: Report initial jack state

[Richard Fitzgerald <rf@opensource.cirrus.com>]

When a jack handler is registered in cs42l42_set_jack() the
initial state should be reported if an attached headphone/headset
has already been detected.

The jack detect sequence takes around 1 second: typically long
enough for the machine driver to probe and register the jack handler
in time to receive the first report from the interrupt handler. So
it is possible on some systems that the correct initial state was seen
simply because of lucky timing. Modular builds were more likely to
miss the reporting of the initial state.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: 4ca239f33737 ("ASoC: cs42l42: Always enable TS_PLUG and TS_UNPLUG interrupts")
---
 sound/soc/codecs/cs42l42.c | 22 ++++++++++++++++++++++
 sound/soc/codecs/cs42l42.h |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 0c4303547fd8..43d98bdb5b5b 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -549,8 +549,25 @@ static int cs42l42_set_jack(struct snd_soc_component *component, struct snd_soc_
 {
 	struct cs42l42_private *cs42l42 = snd_soc_component_get_drvdata(component);
 
+	/* Prevent race with interrupt handler */
+	mutex_lock(&cs42l42->jack_detect_mutex);
 	cs42l42->jack = jk;
 
+	if (jk) {
+		switch (cs42l42->hs_type) {
+		case CS42L42_PLUG_CTIA:
+		case CS42L42_PLUG_OMTP:
+			snd_soc_jack_report(jk, SND_JACK_HEADSET, SND_JACK_HEADSET);
+			break;
+		case CS42L42_PLUG_HEADPHONE:
+			snd_soc_jack_report(jk, SND_JACK_HEADPHONE, SND_JACK_HEADPHONE);
+			break;
+		default:
+			break;
+		}
+	}
+	mutex_unlock(&cs42l42->jack_detect_mutex);
+
 	return 0;
 }
 
@@ -1618,6 +1635,8 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 		CS42L42_M_DETECT_FT_MASK |
 		CS42L42_M_HSBIAS_HIZ_MASK);
 
+	mutex_lock(&cs42l42->jack_detect_mutex);
+
 	/* Check auto-detect status */
 	if ((~masks[5]) & irq_params_table[5].mask) {
 		if (stickies[5] & CS42L42_HSDET_AUTO_DONE_MASK) {
@@ -1686,6 +1705,8 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 		}
 	}
 
+	mutex_unlock(&cs42l42->jack_detect_mutex);
+
 	return IRQ_HANDLED;
 }
 
@@ -2033,6 +2054,7 @@ static int cs42l42_i2c_probe(struct i2c_client *i2c_client,
 
 	cs42l42->dev = &i2c_client->dev;
 	i2c_set_clientdata(i2c_client, cs42l42);
+	mutex_init(&cs42l42->jack_detect_mutex);
 
 	cs42l42->regmap = devm_regmap_init_i2c(i2c_client, &cs42l42_regmap);
 	if (IS_ERR(cs42l42->regmap)) {
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 75ade987d0db..9fff183dce8e 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/sound/soc/codecs/cs42l42.h
@@ -12,6 +12,7 @@
 #ifndef __CS42L42_H__
 #define __CS42L42_H__
 
+#include <linux/mutex.h>
 #include <sound/jack.h>
 
 #define CS42L42_PAGE_REGISTER	0x00	/* Page Select Register */
@@ -841,6 +842,7 @@ struct  cs42l42_private {
 	struct gpio_desc *reset_gpio;
 	struct completion pdn_done;
 	struct snd_soc_jack *jack;
+	struct mutex jack_detect_mutex;
 	int pll_config;
 	int bclk;
 	u32 sclk;
-- 
2.11.0