ASoC: cs35l56: Add system suspend handling

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

This set of patches adds handling for system suspend.
Patches 1..4 make some code changes that simplify the
suspend implementation, mainly to avoid race conditions.

There are two seperate aspects to suspend, and these have
been done as two patches:
- the main suspend-resume handling,
- re-loading the firmware if necessary after resume.

include/sound/cs35l56.h

@@ -95,6 +95,7 @@
 #define CS35L56_MAIN_RENDER_USER_MUTE			0x3400024
 #define CS35L56_MAIN_RENDER_USER_VOLUME			0x340002C
 #define CS35L56_MAIN_POSTURE_NUMBER			0x3400094
+#define CS35L56_PROTECTION_STATUS			0x34000D8
 #define CS35L56_TRANSDUCER_ACTUAL_PS			0x3400150
 #define CS35L56_DSP1_YMEM_UNPACKED24_6141		0x3405FF4
 #define CS35L56_DSP1_PMEM_0				0x3800000
@@ -216,6 +217,9 @@
 #define CS35L56_MAIN_POSTURE_MAX			255
 #define CS35L56_MAIN_POSTURE_MASK			CS35L56_MAIN_POSTURE_MAX
 
+/* CS35L56_PROTECTION_STATUS */
+#define CS35L56_FIRMWARE_MISSING			BIT(0)
+
 /* Software Values */
 #define CS35L56_HALO_STATE_SHUTDOWN			1
 #define CS35L56_HALO_STATE_BOOT_DONE			2

sound/soc/codecs/cs35l56-sdw.c

@@ -450,6 +450,39 @@ static int __maybe_unused cs35l56_sdw_runtime_resume(struct device *dev)
 	return 0;
 }
 
+static int __maybe_unused cs35l56_sdw_system_suspend(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	if (!cs35l56->init_done)
+		return 0;
+
+	/*
+	 * Disable SoundWire interrupts.
+	 * Flush - don't cancel because that could leave an unbalanced pm_runtime_get.
+	 */
+	cs35l56->sdw_irq_no_unmask = true;
+	flush_work(&cs35l56->sdw_irq_work);
+
+	/* Mask interrupts and flush in case sdw_irq_work was queued again */
+	sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_MASK_1, 0);
+	sdw_read_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_STAT_1);
+	sdw_write_no_pm(cs35l56->sdw_peripheral, CS35L56_SDW_GEN_INT_STAT_1, 0xFF);
+	flush_work(&cs35l56->sdw_irq_work);
+
+	return cs35l56_system_suspend(dev);
+}
+
+static int __maybe_unused cs35l56_sdw_system_resume(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	cs35l56->sdw_irq_no_unmask = false;
+	/* runtime_resume re-enables the interrupt */
+
+	return cs35l56_system_resume(dev);
+}
+
 static int cs35l56_sdw_probe(struct sdw_slave *peripheral, const struct sdw_device_id *id)
 {
 	struct device *dev = &peripheral->dev;
@@ -499,6 +532,9 @@ static int cs35l56_sdw_remove(struct sdw_slave *peripheral)
 
 static const struct dev_pm_ops cs35l56_sdw_pm = {
 	SET_RUNTIME_PM_OPS(cs35l56_sdw_runtime_suspend, cs35l56_sdw_runtime_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(cs35l56_sdw_system_suspend, cs35l56_sdw_system_resume)
+	LATE_SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend_late, cs35l56_system_resume_early)
+	/* NOIRQ stage not needed, SoundWire doesn't use a hard IRQ */
 };
 
 static const struct sdw_device_id cs35l56_sdw_id[] = {

sound/soc/codecs/cs35l56.c

@@ -11,8 +11,10 @@
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
 #include <linux/math.h>
 #include <linux/module.h>
+#include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
@@ -32,6 +34,23 @@
 static int cs35l56_dsp_event(struct snd_soc_dapm_widget *w,
 			     struct snd_kcontrol *kcontrol, int event);
 
+static int cs35l56_mbox_send(struct cs35l56_private *cs35l56, unsigned int command)
+{
+	unsigned int val;
+	int ret;
+
+	regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1, command);
+	ret = regmap_read_poll_timeout(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
+				       val, (val == 0),
+				       CS35L56_MBOX_POLL_US, CS35L56_MBOX_TIMEOUT_US);
+	if (ret) {
+		dev_warn(cs35l56->dev, "MBOX command %#x failed: %d\n", command, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int cs35l56_wait_dsp_ready(struct cs35l56_private *cs35l56)
 {
 	int ret;
@@ -182,10 +201,45 @@ static SOC_VALUE_ENUM_SINGLE_DECL(cs35l56_sdw1tx6_enum,
 static const struct snd_kcontrol_new sdw1_tx6_mux =
 	SOC_DAPM_ENUM("SDW1TX6 SRC", cs35l56_sdw1tx6_enum);
 
+static int cs35l56_play_event(struct snd_soc_dapm_widget *w,
+			      struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_component *component = snd_soc_dapm_to_component(w->dapm);
+	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(component);
+	unsigned int val;
+	int ret;
+
+	dev_dbg(cs35l56->dev, "play: %d\n", event);
+
+	switch (event) {
+	case SND_SOC_DAPM_PRE_PMU:
+		/* Don't wait for ACK, we check in POST_PMU that it completed */
+		return regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
+				    CS35L56_MBOX_CMD_AUDIO_PLAY);
+	case SND_SOC_DAPM_POST_PMU:
+		/* Wait for firmware to enter PS0 power state */
+		ret = regmap_read_poll_timeout(cs35l56->regmap,
+					       CS35L56_TRANSDUCER_ACTUAL_PS,
+					       val, (val == CS35L56_PS0),
+					       CS35L56_PS0_POLL_US,
+					       CS35L56_PS0_TIMEOUT_US);
+		if (ret)
+			dev_err(cs35l56->dev, "PS0 wait failed: %d\n", ret);
+		return ret;
+	case SND_SOC_DAPM_POST_PMD:
+		return cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PAUSE);
+	default:
+		return 0;
+	}
+}
+
 static const struct snd_soc_dapm_widget cs35l56_dapm_widgets[] = {
 	SND_SOC_DAPM_REGULATOR_SUPPLY("VDD_B", 0, 0),
 	SND_SOC_DAPM_REGULATOR_SUPPLY("VDD_AMP", 0, 0),
 
+	SND_SOC_DAPM_SUPPLY("PLAY", SND_SOC_NOPM, 0, 0, cs35l56_play_event,
+			    SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_POST_PMD),
+
 	SND_SOC_DAPM_OUT_DRV("AMP", SND_SOC_NOPM, 0, 0, NULL, 0),
 	SND_SOC_DAPM_OUTPUT("SPK"),
 
@@ -252,6 +306,9 @@ static const struct snd_soc_dapm_route cs35l56_audio_map[] = {
 	{ "AMP", NULL, "VDD_B" },
 	{ "AMP", NULL, "VDD_AMP" },
 
+	{ "ASP1 Playback", NULL, "PLAY" },
+	{ "SDW1 Playback", NULL, "PLAY" },
+
 	{ "ASP1RX1", NULL, "ASP1 Playback" },
 	{ "ASP1RX2", NULL, "ASP1 Playback" },
 	{ "DSP1", NULL, "ASP1RX1" },
@@ -288,23 +345,6 @@ static const struct snd_soc_dapm_route cs35l56_audio_map[] = {
 	{ "SDW1 Capture", NULL, "SDW1 TX6 Source" },
 };
 
-static int cs35l56_mbox_send(struct cs35l56_private *cs35l56, unsigned int command)
-{
-	unsigned int val;
-	int ret;
-
-	regmap_write(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1, command);
-	ret = regmap_read_poll_timeout(cs35l56->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1,
-				       val, (val == 0),
-				       CS35L56_MBOX_POLL_US, CS35L56_MBOX_TIMEOUT_US);
-	if (ret) {
-		dev_warn(cs35l56->dev, "MBOX command %#x failed: %d\n", command, ret);
-		return ret;
-	}
-
-	return 0;
-}
-
 static int cs35l56_dsp_event(struct snd_soc_dapm_widget *w,
 			     struct snd_kcontrol *kcontrol, int event)
 {
@@ -611,43 +651,11 @@ static int cs35l56_asp_dai_set_sysclk(struct snd_soc_dai *dai,
 	return 0;
 }
 
-static int cs35l56_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
-{
-	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(dai->component);
-	unsigned int val;
-	int ret;
-
-	dev_dbg(cs35l56->dev, "%s: %d %s\n", __func__, stream, mute ? "mute" : "unmute");
-
-	if (stream != SNDRV_PCM_STREAM_PLAYBACK)
-		return 0;
-
-	if (mute) {
-		ret = cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PAUSE);
-	} else {
-		ret = cs35l56_mbox_send(cs35l56, CS35L56_MBOX_CMD_AUDIO_PLAY);
-		if (ret == 0) {
-			/* Wait for firmware to enter PS0 power state */
-			ret = regmap_read_poll_timeout(cs35l56->regmap,
-						       CS35L56_TRANSDUCER_ACTUAL_PS,
-						       val, (val == CS35L56_PS0),
-						       CS35L56_PS0_POLL_US,
-						       CS35L56_PS0_TIMEOUT_US);
-			if (ret)
-				dev_err(cs35l56->dev, "PS0 wait failed: %d\n", ret);
-			ret = 0;
-		}
-	}
-
-	return ret;
-}
-
 static const struct snd_soc_dai_ops cs35l56_ops = {
 	.set_fmt = cs35l56_asp_dai_set_fmt,
 	.set_tdm_slot = cs35l56_asp_dai_set_tdm_slot,
 	.hw_params = cs35l56_asp_dai_hw_params,
 	.set_sysclk = cs35l56_asp_dai_set_sysclk,
-	.mute_stream = cs35l56_mute_stream,
 };
 
 static void cs35l56_sdw_dai_shutdown(struct snd_pcm_substream *substream,
@@ -749,7 +757,6 @@ static const struct snd_soc_dai_ops cs35l56_sdw_dai_ops = {
 	.shutdown = cs35l56_sdw_dai_shutdown,
 	.hw_params = cs35l56_sdw_dai_hw_params,
 	.hw_free = cs35l56_sdw_dai_hw_free,
-	.mute_stream = cs35l56_mute_stream,
 	.set_stream = cs35l56_sdw_dai_set_stream,
 };
 
@@ -861,13 +868,14 @@ static void cs35l56_dsp_work(struct work_struct *work)
 	unsigned int val;
 	int ret = 0;
 
-	if (!wait_for_completion_timeout(&cs35l56->init_completion,
+	if (!cs35l56->init_done &&
+	    !wait_for_completion_timeout(&cs35l56->init_completion,
 					 msecs_to_jiffies(5000))) {
 		dev_err(cs35l56->dev, "%s: init_completion timed out\n", __func__);
 		goto complete;
 	}
 
-	if (!cs35l56->init_done || cs35l56->removing)
+	if (!cs35l56->init_done)
 		goto complete;
 
 	cs35l56->dsp.part = devm_kasprintf(cs35l56->dev, GFP_KERNEL, "cs35l56%s-%02x",
@@ -917,9 +925,6 @@ static void cs35l56_dsp_work(struct work_struct *work)
 		goto err;
 	}
 
-	if (cs35l56->removing)
-		goto err;
-
 	mutex_lock(&cs35l56->irq_lock);
 
 	init_completion(&cs35l56->init_completion);
@@ -941,6 +946,7 @@ static void cs35l56_dsp_work(struct work_struct *work)
 		goto err_unlock;
 	}
 
+	regmap_clear_bits(cs35l56->regmap, CS35L56_PROTECTION_STATUS, CS35L56_FIRMWARE_MISSING);
 	cs35l56->fw_patched = true;
 
 err_unlock:
@@ -967,7 +973,6 @@ static int cs35l56_component_probe(struct snd_soc_component *component)
 
 	BUILD_BUG_ON(ARRAY_SIZE(cs35l56_tx_input_texts) != ARRAY_SIZE(cs35l56_tx_input_values));
 
-	cs35l56->removing = false;
 	cs35l56->component = component;
 	wm_adsp2_component_probe(&cs35l56->dsp, component);
 
@@ -984,8 +989,6 @@ static void cs35l56_component_remove(struct snd_soc_component *component)
 {
 	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(component);
 
-	cs35l56->removing = true;
-	complete(&cs35l56->init_completion);
 	cancel_work_sync(&cs35l56->dsp_work);
 }
 
@@ -1024,6 +1027,8 @@ static const struct snd_soc_component_driver soc_component_dev_cs35l56 = {
 	.num_controls = ARRAY_SIZE(cs35l56_controls),
 
 	.set_bias_level = cs35l56_set_bias_level,
+
+	.suspend_bias_off = 1, /* see cs35l56_system_resume() */
 };
 
 static const struct reg_sequence cs35l56_hibernate_seq[] = {
@@ -1102,10 +1107,8 @@ int cs35l56_runtime_resume_common(struct cs35l56_private *cs35l56)
 	unsigned int val;
 	int ret;
 
-	if (!cs35l56->can_hibernate) {
-		regcache_cache_only(cs35l56->regmap, false);
+	if (!cs35l56->can_hibernate)
 		goto out_sync;
-	}
 
 	if (!cs35l56->sdw_peripheral) {
 		/*
@@ -1120,6 +1123,7 @@ int cs35l56_runtime_resume_common(struct cs35l56_private *cs35l56)
 			     CS35L56_CONTROL_PORT_READY_US + 400);
 	}
 
+out_sync:
 	regcache_cache_only(cs35l56->regmap, false);
 
 	ret = cs35l56_wait_for_firmware_boot(cs35l56);
@@ -1132,7 +1136,6 @@ int cs35l56_runtime_resume_common(struct cs35l56_private *cs35l56)
 	if (ret)
 		goto err;
 
-out_sync:
 	/* BOOT_DONE will be 1 if the amp reset */
 	regmap_read(cs35l56->regmap, CS35L56_IRQ1_EINT_4, &val);
 	if (val & CS35L56_OTP_BOOT_DONE_MASK) {
@@ -1156,6 +1159,189 @@ int cs35l56_runtime_resume_common(struct cs35l56_private *cs35l56)
 }
 EXPORT_SYMBOL_NS_GPL(cs35l56_runtime_resume_common, SND_SOC_CS35L56_CORE);
 
+static int cs35l56_is_fw_reload_needed(struct cs35l56_private *cs35l56)
+{
+	unsigned int val;
+	int ret;
+
+	/* Nothing to re-patch if we haven't done any patching yet. */
+	if (!cs35l56->fw_patched)
+		return false;
+
+	/*
+	 * If we have control of RESET we will have asserted it so the firmware
+	 * will need re-patching.
+	 */
+	if (cs35l56->reset_gpio)
+		return true;
+
+	/*
+	 * In secure mode FIRMWARE_MISSING is cleared by the BIOS loader so
+	 * can't be used here to test for memory retention.
+	 * Assume that tuning must be re-loaded.
+	 */
+	if (cs35l56->secured)
+		return true;
+
+	ret = pm_runtime_resume_and_get(cs35l56->dev);
+	if (ret) {
+		dev_err(cs35l56->dev, "Failed to runtime_get: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_read(cs35l56->regmap, CS35L56_PROTECTION_STATUS, &val);
+	if (ret)
+		dev_err(cs35l56->dev, "Failed to read PROTECTION_STATUS: %d\n", ret);
+	else
+		ret = !!(val & CS35L56_FIRMWARE_MISSING);
+
+	pm_runtime_put_autosuspend(cs35l56->dev);
+
+	return ret;
+}
+
+int cs35l56_system_suspend(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "system_suspend\n");
+
+	if (cs35l56->component)
+		flush_work(&cs35l56->dsp_work);
+
+	/*
+	 * The interrupt line is normally shared, but after we start suspending
+	 * we can't check if our device is the source of an interrupt, and can't
+	 * clear it. Prevent this race by temporarily disabling the parent irq
+	 * until we reach _no_irq.
+	 */
+	if (cs35l56->irq)
+		disable_irq(cs35l56->irq);
+
+	return pm_runtime_force_suspend(dev);
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_suspend);
+
+int cs35l56_system_suspend_late(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "system_suspend_late\n");
+
+	/*
+	 * Assert RESET before removing supplies.
+	 * RESET is usually shared by all amps so it must not be asserted until
+	 * all driver instances have done their suspend() stage.
+	 */
+	if (cs35l56->reset_gpio) {
+		gpiod_set_value_cansleep(cs35l56->reset_gpio, 0);
+		usleep_range(CS35L56_RESET_PULSE_MIN_US, CS35L56_RESET_PULSE_MIN_US + 400);
+	}
+
+	regulator_bulk_disable(ARRAY_SIZE(cs35l56->supplies), cs35l56->supplies);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_suspend_late);
+
+int cs35l56_system_suspend_no_irq(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "system_suspend_no_irq\n");
+
+	/* Handlers are now disabled so the parent IRQ can safely be re-enabled. */
+	if (cs35l56->irq)
+		enable_irq(cs35l56->irq);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_suspend_no_irq);
+
+int cs35l56_system_resume_no_irq(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "system_resume_no_irq\n");
+
+	/*
+	 * WAKE interrupts unmask if the CS35L56 hibernates, which can cause
+	 * spurious interrupts, and the interrupt line is normally shared.
+	 * We can't check if our device is the source of an interrupt, and can't
+	 * clear it, until it has fully resumed. Prevent this race by temporarily
+	 * disabling the parent irq until we complete resume().
+	 */
+	if (cs35l56->irq)
+		disable_irq(cs35l56->irq);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_resume_no_irq);
+
+int cs35l56_system_resume_early(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+	int ret;
+
+	dev_dbg(dev, "system_resume_early\n");
+
+	/* Ensure a spec-compliant RESET pulse. */
+	if (cs35l56->reset_gpio) {
+		gpiod_set_value_cansleep(cs35l56->reset_gpio, 0);
+		usleep_range(CS35L56_RESET_PULSE_MIN_US, CS35L56_RESET_PULSE_MIN_US + 400);
+	}
+
+	/* Enable supplies before releasing RESET. */
+	ret = regulator_bulk_enable(ARRAY_SIZE(cs35l56->supplies), cs35l56->supplies);
+	if (ret) {
+		dev_err(dev, "system_resume_early failed to enable supplies: %d\n", ret);
+		return ret;
+	}
+
+	/* Release shared RESET before drivers start resume(). */
+	gpiod_set_value_cansleep(cs35l56->reset_gpio, 1);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_resume_early);
+
+int cs35l56_system_resume(struct device *dev)
+{
+	struct cs35l56_private *cs35l56 = dev_get_drvdata(dev);
+	int ret;
+
+	dev_dbg(dev, "system_resume\n");
+
+	/* Undo pm_runtime_force_suspend() before re-enabling the irq */
+	ret = pm_runtime_force_resume(dev);
+	if (cs35l56->irq)
+		enable_irq(cs35l56->irq);
+
+	if (ret)
+		return ret;
+
+	/* Firmware won't have been loaded if the component hasn't probed */
+	if (!cs35l56->component)
+		return 0;
+
+	ret = cs35l56_is_fw_reload_needed(cs35l56);
+	dev_dbg(cs35l56->dev, "fw_reload_needed: %d\n", ret);
+	if (ret < 1)
+		return ret;
+
+	cs35l56->fw_patched = false;
+	init_completion(&cs35l56->dsp_ready_completion);
+	queue_work(cs35l56->dsp_wq, &cs35l56->dsp_work);
+
+	/*
+	 * suspend_bias_off ensures we are now in BIAS_OFF so there will be
+	 * a BIAS_OFF->BIAS_STANDBY transition to complete dsp patching.
+	 */
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cs35l56_system_resume);
+
 static int cs35l56_dsp_init(struct cs35l56_private *cs35l56)
 {
 	struct wm_adsp *dsp;
@@ -1453,6 +1639,9 @@ EXPORT_SYMBOL_NS_GPL(cs35l56_remove, SND_SOC_CS35L56_CORE);
 
 const struct dev_pm_ops cs35l56_pm_ops_i2c_spi = {
 	SET_RUNTIME_PM_OPS(cs35l56_runtime_suspend, cs35l56_runtime_resume_i2c_spi, NULL)
+	SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend, cs35l56_system_resume)
+	LATE_SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend_late, cs35l56_system_resume_early)
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(cs35l56_system_suspend_no_irq, cs35l56_system_resume_no_irq)
 };
 EXPORT_SYMBOL_NS_GPL(cs35l56_pm_ops_i2c_spi, SND_SOC_CS35L56_CORE);
 

sound/soc/codecs/cs35l56.h

@@ -49,7 +49,6 @@ struct cs35l56_private {
 	bool soft_resetting;
 	bool init_done;
 	bool sdw_attached;
-	bool removing;
 	bool fw_patched;
 	bool can_hibernate;
 	struct completion init_completion;
@@ -68,6 +67,12 @@ extern const struct dev_pm_ops cs35l56_pm_ops_i2c_spi;
 
 int cs35l56_runtime_suspend(struct device *dev);
 int cs35l56_runtime_resume_common(struct cs35l56_private *cs35l56);
+int cs35l56_system_suspend(struct device *dev);
+int cs35l56_system_suspend_late(struct device *dev);
+int cs35l56_system_suspend_no_irq(struct device *dev);
+int cs35l56_system_resume_no_irq(struct device *dev);
+int cs35l56_system_resume_early(struct device *dev);
+int cs35l56_system_resume(struct device *dev);
 irqreturn_t cs35l56_irq(int irq, void *data);
 int cs35l56_irq_request(struct cs35l56_private *cs35l56);
 int cs35l56_common_probe(struct cs35l56_private *cs35l56);