ASOC: cs42l42: Add support for system suspend

Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:

Add system suspend and resume handlers so that the cs42l42 is cleanly
put into power-off state during system suspend and the registers are
restored in resume.

sound/soc/codecs/cs42l42.c

@@ -550,7 +550,7 @@ 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);
+	mutex_lock(&cs42l42->irq_lock);
 	cs42l42->jack = jk;
 
 	if (jk) {
@@ -566,7 +566,7 @@ static int cs42l42_set_jack(struct snd_soc_component *component, struct snd_soc_
 			break;
 		}
 	}
-	mutex_unlock(&cs42l42->jack_detect_mutex);
+	mutex_unlock(&cs42l42->irq_lock);
 
 	return 0;
 }
@@ -1613,6 +1613,11 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 	unsigned int i;
 	int report = 0;
 
+	mutex_lock(&cs42l42->irq_lock);
+	if (cs42l42->suspended) {
+		mutex_unlock(&cs42l42->irq_lock);
+		return IRQ_NONE;
+	}
 
 	/* Read sticky registers to clear interurpt */
 	for (i = 0; i < ARRAY_SIZE(stickies); i++) {
@@ -1635,9 +1640,11 @@ 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 */
+	/*
+	 * Check auto-detect status. Don't assume a previous unplug event has
+	 * cleared the flags. If the jack is unplugged and plugged during
+	 * system suspend there won't have been an unplug event.
+	 */
 	if ((~masks[5]) & irq_params_table[5].mask) {
 		if (stickies[5] & CS42L42_HSDET_AUTO_DONE_MASK) {
 			cs42l42_process_hs_type_detect(cs42l42);
@@ -1645,11 +1652,15 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 			case CS42L42_PLUG_CTIA:
 			case CS42L42_PLUG_OMTP:
 				snd_soc_jack_report(cs42l42->jack, SND_JACK_HEADSET,
-						    SND_JACK_HEADSET);
+						    SND_JACK_HEADSET |
+						    SND_JACK_BTN_0 | SND_JACK_BTN_1 |
+						    SND_JACK_BTN_2 | SND_JACK_BTN_3);
 				break;
 			case CS42L42_PLUG_HEADPHONE:
 				snd_soc_jack_report(cs42l42->jack, SND_JACK_HEADPHONE,
-						    SND_JACK_HEADPHONE);
+						    SND_JACK_HEADSET |
+						    SND_JACK_BTN_0 | SND_JACK_BTN_1 |
+						    SND_JACK_BTN_2 | SND_JACK_BTN_3);
 				break;
 			default:
 				break;
@@ -1705,7 +1716,7 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 		}
 	}
 
-	mutex_unlock(&cs42l42->jack_detect_mutex);
+	mutex_unlock(&cs42l42->irq_lock);
 
 	return IRQ_HANDLED;
 }
@@ -2040,6 +2051,138 @@ static int cs42l42_handle_device_data(struct device *dev,
 	return 0;
 }
 
+/* Datasheet suspend sequence */
+static const struct reg_sequence __maybe_unused cs42l42_shutdown_seq[] = {
+	REG_SEQ0(CS42L42_MIC_DET_CTL1,		0x9F),
+	REG_SEQ0(CS42L42_ADC_OVFL_INT_MASK,	0x01),
+	REG_SEQ0(CS42L42_MIXER_INT_MASK,	0x0F),
+	REG_SEQ0(CS42L42_SRC_INT_MASK,		0x0F),
+	REG_SEQ0(CS42L42_ASP_RX_INT_MASK,	0x1F),
+	REG_SEQ0(CS42L42_ASP_TX_INT_MASK,	0x0F),
+	REG_SEQ0(CS42L42_CODEC_INT_MASK,	0x03),
+	REG_SEQ0(CS42L42_SRCPL_INT_MASK,	0x7F),
+	REG_SEQ0(CS42L42_VPMON_INT_MASK,	0x01),
+	REG_SEQ0(CS42L42_PLL_LOCK_INT_MASK,	0x01),
+	REG_SEQ0(CS42L42_TSRS_PLUG_INT_MASK,	0x0F),
+	REG_SEQ0(CS42L42_WAKE_CTL,		0xE1),
+	REG_SEQ0(CS42L42_DET_INT1_MASK,		0xE0),
+	REG_SEQ0(CS42L42_DET_INT2_MASK,		0xFF),
+	REG_SEQ0(CS42L42_MIXER_CHA_VOL,		0x3F),
+	REG_SEQ0(CS42L42_MIXER_ADC_VOL,		0x3F),
+	REG_SEQ0(CS42L42_MIXER_CHB_VOL,		0x3F),
+	REG_SEQ0(CS42L42_HP_CTL,		0x0F),
+	REG_SEQ0(CS42L42_ASP_RX_DAI0_EN,	0x00),
+	REG_SEQ0(CS42L42_ASP_CLK_CFG,		0x00),
+	REG_SEQ0(CS42L42_HSDET_CTL2,		0x00),
+	REG_SEQ0(CS42L42_PWR_CTL1,		0xFE),
+	REG_SEQ0(CS42L42_PWR_CTL2,		0x8C),
+	REG_SEQ0(CS42L42_DAC_CTL2,		0x02),
+	REG_SEQ0(CS42L42_HS_CLAMP_DISABLE,	0x00),
+	REG_SEQ0(CS42L42_MISC_DET_CTL,		0x03),
+	REG_SEQ0(CS42L42_TIPSENSE_CTL,		0x02),
+	REG_SEQ0(CS42L42_HSBIAS_SC_AUTOCTL,	0x03),
+	REG_SEQ0(CS42L42_PWR_CTL1,		0xFF)
+};
+
+static int __maybe_unused cs42l42_suspend(struct device *dev)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
+	unsigned int reg;
+	u8 save_regs[ARRAY_SIZE(cs42l42_shutdown_seq)];
+	int i, ret;
+
+	/*
+	 * Wait for threaded irq handler to be idle and stop it processing
+	 * future interrupts. This ensures a safe disable if the interrupt
+	 * is shared.
+	 */
+	mutex_lock(&cs42l42->irq_lock);
+	cs42l42->suspended = true;
+
+	/* Save register values that will be overwritten by shutdown sequence */
+	for (i = 0; i < ARRAY_SIZE(cs42l42_shutdown_seq); ++i) {
+		regmap_read(cs42l42->regmap, cs42l42_shutdown_seq[i].reg, &reg);
+		save_regs[i] = (u8)reg;
+	}
+
+	/* Shutdown codec */
+	regmap_multi_reg_write(cs42l42->regmap,
+			       cs42l42_shutdown_seq,
+			       ARRAY_SIZE(cs42l42_shutdown_seq));
+
+	/* All interrupt sources are now disabled */
+	mutex_unlock(&cs42l42->irq_lock);
+
+	/* Wait for power-down complete */
+	msleep(CS42L42_PDN_DONE_TIME_MS);
+	ret = regmap_read_poll_timeout(cs42l42->regmap,
+				       CS42L42_CODEC_STATUS, reg,
+				       (reg & CS42L42_PDN_DONE_MASK),
+				       CS42L42_PDN_DONE_POLL_US,
+				       CS42L42_PDN_DONE_TIMEOUT_US);
+	if (ret)
+		dev_warn(dev, "Failed to get PDN_DONE: %d\n", ret);
+
+	/* Discharge FILT+ */
+	regmap_update_bits(cs42l42->regmap, CS42L42_PWR_CTL2,
+			   CS42L42_DISCHARGE_FILT_MASK, CS42L42_DISCHARGE_FILT_MASK);
+	msleep(CS42L42_FILT_DISCHARGE_TIME_MS);
+
+	regcache_cache_only(cs42l42->regmap, true);
+	gpiod_set_value_cansleep(cs42l42->reset_gpio, 0);
+	regulator_bulk_disable(ARRAY_SIZE(cs42l42->supplies), cs42l42->supplies);
+
+	/* Restore register values to the regmap cache */
+	for (i = 0; i < ARRAY_SIZE(cs42l42_shutdown_seq); ++i)
+		regmap_write(cs42l42->regmap, cs42l42_shutdown_seq[i].reg, save_regs[i]);
+
+	/* The cached address page register value is now stale */
+	regcache_drop_region(cs42l42->regmap, CS42L42_PAGE_REGISTER, CS42L42_PAGE_REGISTER);
+
+	dev_dbg(dev, "System suspended\n");
+
+	return 0;
+
+}
+
+static int __maybe_unused cs42l42_resume(struct device *dev)
+{
+	struct cs42l42_private *cs42l42 = dev_get_drvdata(dev);
+	int ret;
+
+	/*
+	 * If jack was unplugged and re-plugged during suspend it could
+	 * have changed type but the tip-sense state hasn't changed.
+	 * Force a plugged state to be re-evaluated.
+	 */
+	if (cs42l42->plug_state != CS42L42_TS_UNPLUG)
+		cs42l42->plug_state = CS42L42_TS_TRANS;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(cs42l42->supplies), cs42l42->supplies);
+	if (ret != 0) {
+		dev_err(dev, "Failed to enable supplies: %d\n", ret);
+		return ret;
+	}
+
+	gpiod_set_value_cansleep(cs42l42->reset_gpio, 1);
+	usleep_range(CS42L42_BOOT_TIME_US, CS42L42_BOOT_TIME_US * 2);
+
+	regcache_cache_only(cs42l42->regmap, false);
+	regcache_mark_dirty(cs42l42->regmap);
+
+	mutex_lock(&cs42l42->irq_lock);
+	/* Sync LATCH_TO_VP first so the VP domain registers sync correctly */
+	regcache_sync_region(cs42l42->regmap, CS42L42_MIC_DET_CTL1, CS42L42_MIC_DET_CTL1);
+	regcache_sync(cs42l42->regmap);
+
+	cs42l42->suspended = false;
+	mutex_unlock(&cs42l42->irq_lock);
+
+	dev_dbg(dev, "System resumed\n");
+
+	return 0;
+}
+
 static int cs42l42_i2c_probe(struct i2c_client *i2c_client,
 				       const struct i2c_device_id *id)
 {
@@ -2054,7 +2197,7 @@ 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);
+	mutex_init(&cs42l42->irq_lock);
 
 	cs42l42->regmap = devm_regmap_init_i2c(i2c_client, &cs42l42_regmap);
 	if (IS_ERR(cs42l42->regmap)) {
@@ -2210,6 +2353,10 @@ static int cs42l42_i2c_remove(struct i2c_client *i2c_client)
 	return 0;
 }
 
+static const struct dev_pm_ops cs42l42_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(cs42l42_suspend, cs42l42_resume)
+};
+
 #ifdef CONFIG_OF
 static const struct of_device_id cs42l42_of_match[] = {
 	{ .compatible = "cirrus,cs42l42", },
@@ -2236,6 +2383,7 @@ MODULE_DEVICE_TABLE(i2c, cs42l42_id);
 static struct i2c_driver cs42l42_i2c_driver = {
 	.driver = {
 		.name = "cs42l42",
+		.pm = &cs42l42_pm_ops,
 		.of_match_table = of_match_ptr(cs42l42_of_match),
 		.acpi_match_table = ACPI_PTR(cs42l42_acpi_match),
 		},

sound/soc/codecs/cs42l42.h

@@ -826,6 +826,10 @@
 #define CS42L42_PLL_LOCK_POLL_US	250
 #define CS42L42_PLL_LOCK_TIMEOUT_US	1250
 #define CS42L42_HP_ADC_EN_TIME_US	20000
+#define CS42L42_PDN_DONE_POLL_US	1000
+#define CS42L42_PDN_DONE_TIMEOUT_US	200000
+#define CS42L42_PDN_DONE_TIME_MS	100
+#define CS42L42_FILT_DISCHARGE_TIME_MS	46
 
 static const char *const cs42l42_supply_names[CS42L42_NUM_SUPPLIES] = {
 	"VA",
@@ -842,7 +846,7 @@ struct  cs42l42_private {
 	struct gpio_desc *reset_gpio;
 	struct completion pdn_done;
 	struct snd_soc_jack *jack;
-	struct mutex jack_detect_mutex;
+	struct mutex irq_lock;
 	int pll_config;
 	int bclk;
 	u32 sclk;
@@ -860,6 +864,7 @@ struct  cs42l42_private {
 	u8 hs_bias_sense_en;
 	u8 stream_use;
 	bool hp_adc_up_pending;
+	bool suspended;
 };
 
 #endif /* __CS42L42_H__ */