[PATCH v3 0/4] SDCA System Suspend Support

[PATCH v3 0/4] SDCA System Suspend Support

[Charles Keepax]

Add support for system suspend into the class driver, now split
out into a separate patch chain.

Where we got to on the previous discussion, was we don't currently
have any parts requiring download on runtime resume, doing so
will add noticeable delay to the runtime resume, and we are not
blocking someone from adding support for firmware download on
runtime resume in the future. Also as runtime resume is really
a kernel concept and power rails are primarily controlled by
ACPI it is quite unlikely anyone will actually power down the
part on a runtime suspend anyway. So this version of the chain
still only downloads firmware on probe and system resume.

Thanks,
Charles

Changes since v2:
 - Update some error message capitalisation.
 - Update some kernel doc.
 - Add a runtime_get to ensure force resume runs the runtime resume.
 - Correct detection of system suspend in FDL IRQ.

Changes since v1:
 - Update SDCA IRQ enable/disable API to be more clear.

Charles Keepax (4):
  ASoC: SDCA: Add SDCA IRQ enable/disable helpers
  ASoC: SDCA: Add basic system suspend support
  ASoC: SDCA: Device boot into the system suspend process
  ASoC: SDCA: Add lock to serialise the Function initialisation

 include/sound/sdca_interrupts.h      |   7 ++
 sound/soc/sdca/sdca_class.c          |  34 ++++++++
 sound/soc/sdca/sdca_class.h          |   2 +
 sound/soc/sdca/sdca_class_function.c | 126 ++++++++++++++++++++++-----
 sound/soc/sdca/sdca_interrupts.c     |  93 ++++++++++++++++++--
 5 files changed, 236 insertions(+), 26 deletions(-)

-- 
2.47.3

[PATCH v3 1/4] ASoC: SDCA: Add SDCA IRQ enable/disable helpers

[Charles Keepax]

Add helpers to enable and disable the SDCA IRQs by Function. These are
useful to sequence the powering down and up around system suspend.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

Changes since v2:
 - Update some kernel doc.

 include/sound/sdca_interrupts.h  |  7 +++
 sound/soc/sdca/sdca_interrupts.c | 76 ++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/include/sound/sdca_interrupts.h b/include/sound/sdca_interrupts.h
index 8f13417d129ab..9bcb5d8fd592b 100644
--- a/include/sound/sdca_interrupts.h
+++ b/include/sound/sdca_interrupts.h
@@ -84,4 +84,11 @@ int sdca_irq_populate(struct sdca_function_data *function,
 struct sdca_interrupt_info *sdca_irq_allocate(struct device *dev,
 					      struct regmap *regmap, int irq);
 
+void sdca_irq_enable_early(struct sdca_function_data *function,
+			   struct sdca_interrupt_info *info);
+void sdca_irq_enable(struct sdca_function_data *function,
+		     struct sdca_interrupt_info *info);
+void sdca_irq_disable(struct sdca_function_data *function,
+		      struct sdca_interrupt_info *info);
+
 #endif
diff --git a/sound/soc/sdca/sdca_interrupts.c b/sound/soc/sdca/sdca_interrupts.c
index ff3a7e405fdcb..afef7bbf613c9 100644
--- a/sound/soc/sdca/sdca_interrupts.c
+++ b/sound/soc/sdca/sdca_interrupts.c
@@ -541,3 +541,79 @@ struct sdca_interrupt_info *sdca_irq_allocate(struct device *sdev,
 	return info;
 }
 EXPORT_SYMBOL_NS_GPL(sdca_irq_allocate, "SND_SOC_SDCA");
+
+static void irq_enable_flags(struct sdca_function_data *function,
+			     struct sdca_interrupt_info *info, bool early)
+{
+	struct sdca_interrupt *interrupt;
+	int i;
+
+	for (i = 0; i < SDCA_MAX_INTERRUPTS; i++) {
+		interrupt = &info->irqs[i];
+
+		if (!interrupt || interrupt->function != function)
+			continue;
+
+		switch (SDCA_CTL_TYPE(interrupt->entity->type,
+				      interrupt->control->sel)) {
+		case SDCA_CTL_TYPE_S(XU, FDL_CURRENTOWNER):
+			if (early)
+				enable_irq(interrupt->irq);
+			break;
+		default:
+			if (!early)
+				enable_irq(interrupt->irq);
+			break;
+		}
+	}
+}
+
+/**
+ * sdca_irq_enable_early - Re-enable early SDCA IRQs for a given function
+ * @function: Pointer to the SDCA Function.
+ * @info: Pointer to the SDCA interrupt info for this device.
+ *
+ * The early version of the IRQ enable allows enabling IRQs which may be
+ * necessary to bootstrap functionality for other IRQs, such as the FDL
+ * process.
+ */
+void sdca_irq_enable_early(struct sdca_function_data *function,
+			   struct sdca_interrupt_info *info)
+{
+	irq_enable_flags(function, info, true);
+}
+EXPORT_SYMBOL_NS_GPL(sdca_irq_enable_early, "SND_SOC_SDCA");
+
+/**
+ * sdca_irq_enable - Re-enable SDCA IRQs for a given function
+ * @function: Pointer to the SDCA Function.
+ * @info: Pointer to the SDCA interrupt info for this device.
+ */
+void sdca_irq_enable(struct sdca_function_data *function,
+		     struct sdca_interrupt_info *info)
+{
+	irq_enable_flags(function, info, false);
+}
+EXPORT_SYMBOL_NS_GPL(sdca_irq_enable, "SND_SOC_SDCA");
+
+/**
+ * sdca_irq_disable - Disable SDCA IRQs for a given function
+ * @function: Pointer to the SDCA Function.
+ * @info: Pointer to the SDCA interrupt info for this device.
+ */
+void sdca_irq_disable(struct sdca_function_data *function,
+		      struct sdca_interrupt_info *info)
+{
+	struct sdca_interrupt *interrupt;
+	int i;
+
+	for (i = 0; i < SDCA_MAX_INTERRUPTS; i++) {
+		interrupt = &info->irqs[i];
+
+		if (!interrupt || interrupt->function != function)
+			continue;
+
+		disable_irq(interrupt->irq);
+	}
+}
+EXPORT_SYMBOL_NS_GPL(sdca_irq_disable, "SND_SOC_SDCA");
-- 
2.47.3

[PATCH v3 2/4] ASoC: SDCA: Add basic system suspend support

[Charles Keepax]

Add basic system suspend support. Disable the IRQs and force runtime
suspend, during system suspend, because the device will likely fully
power down during suspend.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

Changes since v2:
 - Update some error message capitalisation.
 - Add a runtime_get to ensure force resume runs the runtime resume.
 - Add comment to note missing operations between early and late IRQ
   enable.

 sound/soc/sdca/sdca_class.c          | 33 ++++++++++++++++++
 sound/soc/sdca/sdca_class_function.c | 51 ++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/sound/soc/sdca/sdca_class.c b/sound/soc/sdca/sdca_class.c
index 349d32933ba85..6d19a183683e8 100644
--- a/sound/soc/sdca/sdca_class.c
+++ b/sound/soc/sdca/sdca_class.c
@@ -238,6 +238,38 @@ static int class_sdw_probe(struct sdw_slave *sdw, const struct sdw_device_id *id
 	return 0;
 }
 
+static int class_suspend(struct device *dev)
+{
+	struct sdca_class_drv *drv = dev_get_drvdata(dev);
+	int ret;
+
+	disable_irq(drv->sdw->irq);
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret) {
+		dev_err(dev, "failed to force suspend: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int class_resume(struct device *dev)
+{
+	struct sdca_class_drv *drv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret) {
+		dev_err(dev, "failed to force resume: %d\n", ret);
+		return ret;
+	}
+
+	enable_irq(drv->sdw->irq);
+
+	return 0;
+}
+
 static int class_runtime_suspend(struct device *dev)
 {
 	struct sdca_class_drv *drv = dev_get_drvdata(dev);
@@ -278,6 +310,7 @@ static int class_runtime_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops class_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(class_suspend, class_resume)
 	RUNTIME_PM_OPS(class_runtime_suspend, class_runtime_resume, NULL)
 };
 
diff --git a/sound/soc/sdca/sdca_class_function.c b/sound/soc/sdca/sdca_class_function.c
index 416948cfb5cb9..7d0a6c0adbfb6 100644
--- a/sound/soc/sdca/sdca_class_function.c
+++ b/sound/soc/sdca/sdca_class_function.c
@@ -33,6 +33,7 @@ struct class_function_drv {
 	struct sdca_class_drv *core;
 
 	struct sdca_function_data *function;
+	bool suspended;
 };
 
 static void class_function_regmap_lock(void *data)
@@ -417,6 +418,14 @@ static int class_function_runtime_resume(struct device *dev)
 	regcache_mark_dirty(drv->regmap);
 	regcache_cache_only(drv->regmap, false);
 
+	if (drv->suspended) {
+		sdca_irq_enable_early(drv->function, drv->core->irq_info);
+		/* TODO: Add FDL process between early and late IRQs */
+		sdca_irq_enable(drv->function, drv->core->irq_info);
+
+		drv->suspended = false;
+	}
+
 	ret = regcache_sync(drv->regmap);
 	if (ret) {
 		dev_err(drv->dev, "failed to restore register cache: %d\n", ret);
@@ -431,7 +440,49 @@ static int class_function_runtime_resume(struct device *dev)
 	return ret;
 }
 
+static int class_function_suspend(struct device *dev)
+{
+	struct auxiliary_device *auxdev = to_auxiliary_dev(dev);
+	struct class_function_drv *drv = auxiliary_get_drvdata(auxdev);
+	int ret;
+
+	drv->suspended = true;
+
+	/* Ensure runtime resume runs on resume */
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret) {
+		dev_err(dev, "failed to resume for suspend: %d\n", ret);
+		return ret;
+	}
+
+	sdca_irq_disable(drv->function, drv->core->irq_info);
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret) {
+		dev_err(dev, "failed to force suspend: %d\n", ret);
+		return ret;
+	}
+
+	pm_runtime_put_noidle(dev);
+
+	return 0;
+}
+
+static int class_function_resume(struct device *dev)
+{
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret) {
+		dev_err(dev, "failed to force resume: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
 static const struct dev_pm_ops class_function_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(class_function_suspend, class_function_resume)
 	RUNTIME_PM_OPS(class_function_runtime_suspend,
 		       class_function_runtime_resume, NULL)
 };
-- 
2.47.3

[PATCH v3 3/4] ASoC: SDCA: Device boot into the system suspend process

[Charles Keepax]

When system suspending the device may be powered off, this means all
state will be lost and the firmware may need to be re-downloaded. Add
the necessary calls to bring the device back up. This also requires that
that the FDL (firmware download) IRQ handler is modified to allow it to
run before runtime PM has been fully restored.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

Changes since v2:
 - Correct detection of system suspend in FDL IRQ.

 sound/soc/sdca/sdca_class_function.c | 72 +++++++++++++++++++---------
 sound/soc/sdca/sdca_interrupts.c     | 17 +++++--
 2 files changed, 62 insertions(+), 27 deletions(-)

diff --git a/sound/soc/sdca/sdca_class_function.c b/sound/soc/sdca/sdca_class_function.c
index 7d0a6c0adbfb6..bbf486d9a3d07 100644
--- a/sound/soc/sdca/sdca_class_function.c
+++ b/sound/soc/sdca/sdca_class_function.c
@@ -211,21 +211,12 @@ static const struct snd_soc_component_driver class_function_component_drv = {
 	.endianness		= 1,
 };
 
-static int class_function_boot(struct class_function_drv *drv)
+static int class_function_init_device(struct class_function_drv *drv,
+				      unsigned int status)
 {
-	unsigned int reg = SDW_SDCA_CTL(drv->function->desc->adr,
-					SDCA_ENTITY_TYPE_ENTITY_0,
-					SDCA_CTL_ENTITY_0_FUNCTION_STATUS, 0);
-	unsigned int val;
 	int ret;
 
-	ret = regmap_read(drv->regmap, reg, &val);
-	if (ret < 0) {
-		dev_err(drv->dev, "failed to read function status: %d\n", ret);
-		return ret;
-	}
-
-	if (!(val & SDCA_CTL_ENTITY_0_FUNCTION_HAS_BEEN_RESET)) {
+	if (!(status & SDCA_CTL_ENTITY_0_FUNCTION_HAS_BEEN_RESET)) {
 		dev_dbg(drv->dev, "reset function device\n");
 
 		ret = sdca_reset_function(drv->dev, drv->function, drv->regmap);
@@ -233,24 +224,36 @@ static int class_function_boot(struct class_function_drv *drv)
 			return ret;
 	}
 
-	if (val & SDCA_CTL_ENTITY_0_FUNCTION_NEEDS_INITIALIZATION) {
+	if (status & SDCA_CTL_ENTITY_0_FUNCTION_NEEDS_INITIALIZATION) {
 		dev_dbg(drv->dev, "write initialisation\n");
 
 		ret = sdca_regmap_write_init(drv->dev, drv->core->dev_regmap,
 					     drv->function);
 		if (ret)
 			return ret;
+	}
 
-		ret = regmap_write(drv->regmap, reg,
-				   SDCA_CTL_ENTITY_0_FUNCTION_NEEDS_INITIALIZATION);
-		if (ret < 0) {
-			dev_err(drv->dev,
-				"failed to clear function init status: %d\n",
-				ret);
-			return ret;
-		}
+	return 0;
+}
+
+static int class_function_boot(struct class_function_drv *drv)
+{
+	unsigned int reg = SDW_SDCA_CTL(drv->function->desc->adr,
+					SDCA_ENTITY_TYPE_ENTITY_0,
+					SDCA_CTL_ENTITY_0_FUNCTION_STATUS, 0);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(drv->regmap, reg, &val);
+	if (ret < 0) {
+		dev_err(drv->dev, "failed to read function status: %d\n", ret);
+		return ret;
 	}
 
+	ret = class_function_init_device(drv, val);
+	if (ret)
+		return ret;
+
 	/* Start FDL process */
 	ret = sdca_irq_populate_early(drv->dev, drv->regmap, drv->function,
 				      drv->core->irq_info);
@@ -419,10 +422,35 @@ static int class_function_runtime_resume(struct device *dev)
 	regcache_cache_only(drv->regmap, false);
 
 	if (drv->suspended) {
+		unsigned int reg = SDW_SDCA_CTL(drv->function->desc->adr,
+						SDCA_ENTITY_TYPE_ENTITY_0,
+						SDCA_CTL_ENTITY_0_FUNCTION_STATUS, 0);
+		unsigned int val;
+
+		ret = regmap_read(drv->regmap, reg, &val);
+		if (ret < 0) {
+			dev_err(drv->dev, "failed to read function status: %d\n", ret);
+			goto err;
+		}
+
+		ret = class_function_init_device(drv, val);
+		if (ret)
+			goto err;
+
 		sdca_irq_enable_early(drv->function, drv->core->irq_info);
-		/* TODO: Add FDL process between early and late IRQs */
+
+		ret = sdca_fdl_sync(drv->dev, drv->function, drv->core->irq_info);
+		if (ret)
+			goto err;
+
 		sdca_irq_enable(drv->function, drv->core->irq_info);
 
+		ret = regmap_write(drv->regmap, reg, 0xFF);
+		if (ret < 0) {
+			dev_err(drv->dev, "failed to clear function status: %d\n", ret);
+			goto err;
+		}
+
 		drv->suspended = false;
 	}
 
diff --git a/sound/soc/sdca/sdca_interrupts.c b/sound/soc/sdca/sdca_interrupts.c
index afef7bbf613c9..cc40732c30ccb 100644
--- a/sound/soc/sdca/sdca_interrupts.c
+++ b/sound/soc/sdca/sdca_interrupts.c
@@ -205,10 +205,16 @@ static irqreturn_t fdl_owner_handler(int irq, void *data)
 	irqreturn_t irqret = IRQ_NONE;
 	int ret;
 
-	ret = pm_runtime_get_sync(dev);
-	if (ret < 0) {
-		dev_err(dev, "failed to resume for fdl: %d\n", ret);
-		goto error;
+	/*
+	 * FDL has to run from the system resume handler, at which point
+	 * we can't wait for the pm runtime.
+	 */
+	if (completion_done(&dev->power.completion)) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0) {
+			dev_err(dev, "failed to resume for fdl: %d\n", ret);
+			goto error;
+		}
 	}
 
 	ret = sdca_fdl_process(interrupt);
@@ -217,7 +223,8 @@ static irqreturn_t fdl_owner_handler(int irq, void *data)
 
 	irqret = IRQ_HANDLED;
 error:
-	pm_runtime_put(dev);
+	if (completion_done(&dev->power.completion))
+		pm_runtime_put(dev);
 	return irqret;
 }
 
-- 
2.47.3

[PATCH v3 4/4] ASoC: SDCA: Add lock to serialise the Function initialisation

[Charles Keepax]

To avoid issues on some devices serialise the boot of each SDCA Function
from the others.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
---

No changes since v2.

 sound/soc/sdca/sdca_class.c          | 1 +
 sound/soc/sdca/sdca_class.h          | 2 ++
 sound/soc/sdca/sdca_class_function.c | 5 +++++
 3 files changed, 8 insertions(+)

diff --git a/sound/soc/sdca/sdca_class.c b/sound/soc/sdca/sdca_class.c
index 6d19a183683e8..918b638acb577 100644
--- a/sound/soc/sdca/sdca_class.c
+++ b/sound/soc/sdca/sdca_class.c
@@ -205,6 +205,7 @@ static int class_sdw_probe(struct sdw_slave *sdw, const struct sdw_device_id *id
 	drv->dev = dev;
 	drv->sdw = sdw;
 	mutex_init(&drv->regmap_lock);
+	mutex_init(&drv->init_lock);
 
 	dev_set_drvdata(drv->dev, drv);
 
diff --git a/sound/soc/sdca/sdca_class.h b/sound/soc/sdca/sdca_class.h
index bb4c9dd124296..6f24ea2bbd381 100644
--- a/sound/soc/sdca/sdca_class.h
+++ b/sound/soc/sdca/sdca_class.h
@@ -28,6 +28,8 @@ struct sdca_class_drv {
 	struct sdca_interrupt_info *irq_info;
 
 	struct mutex regmap_lock;
+	/* Serialise function initialisations */
+	struct mutex init_lock;
 	struct work_struct boot_work;
 	struct completion device_attach;
 
diff --git a/sound/soc/sdca/sdca_class_function.c b/sound/soc/sdca/sdca_class_function.c
index bbf486d9a3d07..0afa41c1ee93c 100644
--- a/sound/soc/sdca/sdca_class_function.c
+++ b/sound/soc/sdca/sdca_class_function.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/auxiliary_bus.h>
+#include <linux/cleanup.h>
 #include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/pm.h>
@@ -244,6 +245,8 @@ static int class_function_boot(struct class_function_drv *drv)
 	unsigned int val;
 	int ret;
 
+	guard(mutex)(&drv->core->init_lock);
+
 	ret = regmap_read(drv->regmap, reg, &val);
 	if (ret < 0) {
 		dev_err(drv->dev, "failed to read function status: %d\n", ret);
@@ -418,6 +421,8 @@ static int class_function_runtime_resume(struct device *dev)
 	struct class_function_drv *drv = auxiliary_get_drvdata(auxdev);
 	int ret;
 
+	guard(mutex)(&drv->core->init_lock);
+
 	regcache_mark_dirty(drv->regmap);
 	regcache_cache_only(drv->regmap, false);
 
-- 
2.47.3

Re: [PATCH v3 0/4] SDCA System Suspend Support

[Pierre-Louis Bossart]

On 1/9/26 15:52, Charles Keepax wrote:
> Add support for system suspend into the class driver, now split
> out into a separate patch chain.
> 
> Where we got to on the previous discussion, was we don't currently
> have any parts requiring download on runtime resume, doing so
> will add noticeable delay to the runtime resume, and we are not
> blocking someone from adding support for firmware download on
> runtime resume in the future. Also as runtime resume is really
> a kernel concept and power rails are primarily controlled by
> ACPI it is quite unlikely anyone will actually power down the
> part on a runtime suspend anyway. So this version of the chain
> still only downloads firmware on probe and system resume.

LGTM, thanks Charles

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
 
> Changes since v2:
>  - Update some error message capitalisation.
>  - Update some kernel doc.
>  - Add a runtime_get to ensure force resume runs the runtime resume.
>  - Correct detection of system suspend in FDL IRQ.
> 
> Changes since v1:
>  - Update SDCA IRQ enable/disable API to be more clear.
> 
> Charles Keepax (4):
>   ASoC: SDCA: Add SDCA IRQ enable/disable helpers
>   ASoC: SDCA: Add basic system suspend support
>   ASoC: SDCA: Device boot into the system suspend process
>   ASoC: SDCA: Add lock to serialise the Function initialisation
> 
>  include/sound/sdca_interrupts.h      |   7 ++
>  sound/soc/sdca/sdca_class.c          |  34 ++++++++
>  sound/soc/sdca/sdca_class.h          |   2 +
>  sound/soc/sdca/sdca_class_function.c | 126 ++++++++++++++++++++++-----
>  sound/soc/sdca/sdca_interrupts.c     |  93 ++++++++++++++++++--
>  5 files changed, 236 insertions(+), 26 deletions(-)
> 

Re: [PATCH v3 0/4] SDCA System Suspend Support

[Mark Brown]

On Fri, 09 Jan 2026 14:52:02 +0000, Charles Keepax wrote:
> Add support for system suspend into the class driver, now split
> out into a separate patch chain.
> 
> Where we got to on the previous discussion, was we don't currently
> have any parts requiring download on runtime resume, doing so
> will add noticeable delay to the runtime resume, and we are not
> blocking someone from adding support for firmware download on
> runtime resume in the future. Also as runtime resume is really
> a kernel concept and power rails are primarily controlled by
> ACPI it is quite unlikely anyone will actually power down the
> part on a runtime suspend anyway. So this version of the chain
> still only downloads firmware on probe and system resume.
> 
> [...]

Applied to

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

Thanks!

[1/4] ASoC: SDCA: Add SDCA IRQ enable/disable helpers
      commit: 9e3d4f794cbe9a4e286b3052cb97908005807aee
[2/4] ASoC: SDCA: Add basic system suspend support
      commit: 7a5214f769c7c953c58971027a762f2e191057d4
[3/4] ASoC: SDCA: Device boot into the system suspend process
      commit: ffd7e8a101110cba86925a2906d925e0db7102f3
[4/4] ASoC: SDCA: Add lock to serialise the Function initialisation
      commit: da7afdc79cba00f952df12cd579e44832d829c0a

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