[PATCH v2 0/3] ASOC: cs42l42: Add support for system suspend

[PATCH v2 0/3] ASOC: cs42l42: Add support for system suspend

[Richard Fitzgerald]

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.

The first two patches separate out two small changes that can stand
alone and are needed to enable the system suspend implementation:

1) Don't rely on there being a jack unplug IRQ before a plug IRQ.
There won't be if the unplug and plug happened while in system suspend.

2) Put a mutex around the entire IRQ handling so that the suspend can
ensure the last run of the IRQ handler has completed before it powers
down.

Changes since V1:
- Hold irq_lock mutex while restoring registers

Richard Fitzgerald (3):
  ASoC: cs42l42: Report full jack status when plug is detected
  ASoC: cs42l42: Change jack_detect_mutex to a lock of all IRQ handling
  ASoC: cs42l42: Handle system suspend

 sound/soc/codecs/cs42l42.c | 166 ++++++++++++++++++++++++++++++++++++++++++---
 sound/soc/codecs/cs42l42.h |   7 +-
 2 files changed, 163 insertions(+), 10 deletions(-)

-- 
2.11.0

[PATCH v2 1/3] ASoC: cs42l42: Report full jack status when plug is detected

[Richard Fitzgerald]

When a plug event is detect report the full state of all status
bits, don't assume that there will have been a previous unplug
event to clear all the bits. Report the state of both HEADPHONE
and MICROPHONE bits according to detected type, and clear all the
button status bits. The current button status is already checked
and reported at the end of the function.

During a system suspend the jack could be unplugged and plugged,
possibly changing the jack type. On resume the interrupt status will
indicate a plug event - there will not be an unplug event to clear
the bits.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 43d98bdb5b5b..2c294868008e 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -1637,7 +1637,11 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 
 	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 +1649,15 @@ 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;
-- 
2.11.0

[PATCH v2 2/3] ASoC: cs42l42: Change jack_detect_mutex to a lock of all IRQ handling

[Richard Fitzgerald]

Rename jack_detect_mutex to irq_lock and make it lock the entire IRQ
handling.

The jack_detect_mutex was introduced to synchronize registering an
ALSA jack handler, via cs42l42_set_jack(), with the jack state
processing in the IRQ handler, and was taken only around the
relevant part of the IRQ handling code.

System suspend will need to synchronize with the IRQ handler thread
so will need a similar mutex that surrounds all of the IRQ handling.
Repurposing the existing jack_detect_mutex is the simplest option.
It does no harm for a call to cs42l42_set_jack() to additionally
block the first few lines of IRQ handling, and the only interrupts
used by the driver are all for jack handling.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 11 +++++------
 sound/soc/codecs/cs42l42.h |  2 +-
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 2c294868008e..f1b95d45af4a 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/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 +1613,7 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 	unsigned int i;
 	int report = 0;
 
+	mutex_lock(&cs42l42->irq_lock);
 
 	/* Read sticky registers to clear interurpt */
 	for (i = 0; i < ARRAY_SIZE(stickies); i++) {
@@ -1635,8 +1636,6 @@ 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. Don't assume a previous unplug event has
 	 * cleared the flags. If the jack is unplugged and plugged during
@@ -1713,7 +1712,7 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 		}
 	}
 
-	mutex_unlock(&cs42l42->jack_detect_mutex);
+	mutex_unlock(&cs42l42->irq_lock);
 
 	return IRQ_HANDLED;
 }
@@ -2062,7 +2061,7 @@ 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)) {
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 9fff183dce8e..53d96287abba 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/sound/soc/codecs/cs42l42.h
@@ -842,7 +842,7 @@ 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;
-- 
2.11.0

[PATCH v2 3/3] ASoC: cs42l42: Handle system suspend

[Richard Fitzgerald]

Add system suspend functions to handle clean power-down on suspend and
restoring registers on resume.

The jack state could change during suspend. Plug->unplug and unplug->plug
are straightforward because this looks no different from any other plug
state change - there will be a plugged or unplugged interrupt pending.
The jack could be unplugged and a different type of jack plugged, and on
resume the plug state would not have changed. Setting plug_state back to
TS_TRANS (transitioning) will make the next plug interrupt after resume
run a type detection.

During system suspend any jack plug/unplug and button events will not be
reported or generate a system wakeup. If the plug state or headset type
has changed it will be reported after resume.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
---
 sound/soc/codecs/cs42l42.c | 141 +++++++++++++++++++++++++++++++++++++++++++++
 sound/soc/codecs/cs42l42.h |   5 ++
 2 files changed, 146 insertions(+)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index f1b95d45af4a..db6ef6cdce15 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -1614,6 +1614,10 @@ static irqreturn_t cs42l42_irq_thread(int irq, void *data)
 	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++) {
@@ -2047,6 +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)
 {
@@ -2217,6 +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", },
@@ -2243,6 +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),
 		},
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 53d96287abba..244b24d1f5e9 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/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",
@@ -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__ */
-- 
2.11.0

Re: [PATCH v2 0/3] ASOC: cs42l42: Add support for system suspend

[Mark Brown]

On Fri, 21 Jan 2022 12:04:09 +0000, Richard Fitzgerald wrote:
> 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.
> 
> The first two patches separate out two small changes that can stand
> alone and are needed to enable the system suspend implementation:
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/3] ASoC: cs42l42: Report full jack status when plug is detected
      commit: 8d06f797f844d04a961f201f886f7f9985edc9bf
[2/3] ASoC: cs42l42: Change jack_detect_mutex to a lock of all IRQ handling
      commit: 5982b5a8ec7ddb076e774bdd0b17d74681ab0943
[3/3] ASoC: cs42l42: Handle system suspend
      commit: f8593e88540052b3feaf1fb36f2c1c0484c9dc14

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark