[RFC][PATCH 2/2] PM / Sleep: Introduce generic callbacks for new device PM phases

["Rafael J. Wysocki" <rjw@sisk.pl>]

From: Rafael J. Wysocki <rjw@sisk.pl>

Introduce generic subsystem callbacks for the new phases of device
suspend/resume during system power transitions: "late suspend",
"early resume", "late freeze", "early thaw", "late poweroff",
"early restore".

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
 drivers/base/power/generic_ops.c |  163 +++++++++++++++++++++++++--------------
 include/linux/pm.h               |    6 +
 2 files changed, 113 insertions(+), 56 deletions(-)

Index: linux/drivers/base/power/generic_ops.c
===================================================================
--- linux.orig/drivers/base/power/generic_ops.c
+++ linux/drivers/base/power/generic_ops.c
@@ -92,59 +92,28 @@ int pm_generic_prepare(struct device *de
 }
 
 /**
- * __pm_generic_call - Generic suspend/freeze/poweroff/thaw subsystem callback.
- * @dev: Device to handle.
- * @event: PM transition of the system under way.
- * @bool: Whether or not this is the "noirq" stage.
- *
- * Execute the PM callback corresponding to @event provided by the driver of
- * @dev, if defined, and return its error code.    Return 0 if the callback is
- * not present.
- */
-static int __pm_generic_call(struct device *dev, int event, bool noirq)
-{
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-	int (*callback)(struct device *);
-
-	if (!pm)
-		return 0;
-
-	switch (event) {
-	case PM_EVENT_SUSPEND:
-		callback = noirq ? pm->suspend_noirq : pm->suspend;
-		break;
-	case PM_EVENT_FREEZE:
-		callback = noirq ? pm->freeze_noirq : pm->freeze;
-		break;
-	case PM_EVENT_HIBERNATE:
-		callback = noirq ? pm->poweroff_noirq : pm->poweroff;
-		break;
-	case PM_EVENT_RESUME:
-		callback = noirq ? pm->resume_noirq : pm->resume;
-		break;
-	case PM_EVENT_THAW:
-		callback = noirq ? pm->thaw_noirq : pm->thaw;
-		break;
-	case PM_EVENT_RESTORE:
-		callback = noirq ? pm->restore_noirq : pm->restore;
-		break;
-	default:
-		callback = NULL;
-		break;
-	}
+ * pm_generic_suspend_noirq - Generic suspend_noirq callback for subsystems.
+ * @dev: Device to suspend.
+ */
+int pm_generic_suspend_noirq(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
-	return callback ? callback(dev) : 0;
+	return pm && pm->suspend_noirq ? pm->suspend_noirq(dev) : 0;
 }
+EXPORT_SYMBOL_GPL(pm_generic_suspend_noirq);
 
 /**
- * pm_generic_suspend_noirq - Generic suspend_noirq callback for subsystems.
+ * pm_generic_suspend_late - Generic suspend_late callback for subsystems.
  * @dev: Device to suspend.
  */
-int pm_generic_suspend_noirq(struct device *dev)
+int pm_generic_suspend_late(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_SUSPEND, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->suspend_late ? pm->suspend_late(dev) : 0;
 }
-EXPORT_SYMBOL_GPL(pm_generic_suspend_noirq);
+EXPORT_SYMBOL_GPL(pm_generic_suspend_late);
 
 /**
  * pm_generic_suspend - Generic suspend callback for subsystems.
@@ -152,7 +121,9 @@ EXPORT_SYMBOL_GPL(pm_generic_suspend_noi
  */
 int pm_generic_suspend(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_SUSPEND, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->suspend ? pm->suspend(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_suspend);
 
@@ -162,17 +133,33 @@ EXPORT_SYMBOL_GPL(pm_generic_suspend);
  */
 int pm_generic_freeze_noirq(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_FREEZE, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->freeze_noirq ? pm->freeze_noirq(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_freeze_noirq);
 
 /**
+ * pm_generic_freeze_late - Generic freeze_late callback for subsystems.
+ * @dev: Device to freeze.
+ */
+int pm_generic_freeze_late(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->freeze_late ? pm->freeze_late(dev) : 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_freeze_late);
+
+/**
  * pm_generic_freeze - Generic freeze callback for subsystems.
  * @dev: Device to freeze.
  */
 int pm_generic_freeze(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_FREEZE, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->freeze ? pm->freeze(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_freeze);
 
@@ -182,17 +169,33 @@ EXPORT_SYMBOL_GPL(pm_generic_freeze);
  */
 int pm_generic_poweroff_noirq(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_HIBERNATE, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->poweroff_noirq ? pm->poweroff_noirq(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_poweroff_noirq);
 
 /**
+ * pm_generic_poweroff_late - Generic poweroff_late callback for subsystems.
+ * @dev: Device to handle.
+ */
+int pm_generic_poweroff_late(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->poweroff_late ? pm->poweroff_late(dev) : 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_poweroff_late);
+
+/**
  * pm_generic_poweroff - Generic poweroff callback for subsystems.
  * @dev: Device to handle.
  */
 int pm_generic_poweroff(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_HIBERNATE, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->poweroff ? pm->poweroff(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_poweroff);
 
@@ -202,17 +205,33 @@ EXPORT_SYMBOL_GPL(pm_generic_poweroff);
  */
 int pm_generic_thaw_noirq(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_THAW, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->thaw_noirq ? pm->thaw_noirq(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_thaw_noirq);
 
 /**
+ * pm_generic_thaw_early - Generic thaw_early callback for subsystems.
+ * @dev: Device to thaw.
+ */
+int pm_generic_thaw_early(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->thaw_early ? pm->thaw_early(dev) : 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_thaw_early);
+
+/**
  * pm_generic_thaw - Generic thaw callback for subsystems.
  * @dev: Device to thaw.
  */
 int pm_generic_thaw(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_THAW, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->thaw ? pm->thaw(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_thaw);
 
@@ -222,17 +241,33 @@ EXPORT_SYMBOL_GPL(pm_generic_thaw);
  */
 int pm_generic_resume_noirq(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_RESUME, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->resume_noirq ? pm->resume_noirq(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_resume_noirq);
 
 /**
+ * pm_generic_resume_early - Generic resume_early callback for subsystems.
+ * @dev: Device to resume.
+ */
+int pm_generic_resume_early(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->resume_early ? pm->resume_early(dev) : 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_resume_early);
+
+/**
  * pm_generic_resume - Generic resume callback for subsystems.
  * @dev: Device to resume.
  */
 int pm_generic_resume(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_RESUME, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->resume ? pm->resume(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_resume);
 
@@ -242,17 +277,33 @@ EXPORT_SYMBOL_GPL(pm_generic_resume);
  */
 int pm_generic_restore_noirq(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_RESTORE, true);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->restore_noirq ? pm->restore_noirq(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_restore_noirq);
 
 /**
+ * pm_generic_restore_early - Generic restore_early callback for subsystems.
+ * @dev: Device to resume.
+ */
+int pm_generic_restore_early(struct device *dev)
+{
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->restore_early ? pm->restore_early(dev) : 0;
+}
+EXPORT_SYMBOL_GPL(pm_generic_restore_early);
+
+/**
  * pm_generic_restore - Generic restore callback for subsystems.
  * @dev: Device to restore.
  */
 int pm_generic_restore(struct device *dev)
 {
-	return __pm_generic_call(dev, PM_EVENT_RESTORE, false);
+	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+
+	return pm && pm->restore ? pm->restore(dev) : 0;
 }
 EXPORT_SYMBOL_GPL(pm_generic_restore);
 
Index: linux/include/linux/pm.h
===================================================================
--- linux.orig/include/linux/pm.h
+++ linux/include/linux/pm.h
@@ -632,17 +632,23 @@ extern void __suspend_report_result(cons
 extern int device_pm_wait_for_dev(struct device *sub, struct device *dev);
 
 extern int pm_generic_prepare(struct device *dev);
+extern int pm_generic_suspend_late(struct device *dev);
 extern int pm_generic_suspend_noirq(struct device *dev);
 extern int pm_generic_suspend(struct device *dev);
+extern int pm_generic_resume_early(struct device *dev);
 extern int pm_generic_resume_noirq(struct device *dev);
 extern int pm_generic_resume(struct device *dev);
 extern int pm_generic_freeze_noirq(struct device *dev);
+extern int pm_generic_freeze_late(struct device *dev);
 extern int pm_generic_freeze(struct device *dev);
 extern int pm_generic_thaw_noirq(struct device *dev);
+extern int pm_generic_thaw_early(struct device *dev);
 extern int pm_generic_thaw(struct device *dev);
 extern int pm_generic_restore_noirq(struct device *dev);
+extern int pm_generic_restore_early(struct device *dev);
 extern int pm_generic_restore(struct device *dev);
 extern int pm_generic_poweroff_noirq(struct device *dev);
+extern int pm_generic_poweroff_late(struct device *dev);
 extern int pm_generic_poweroff(struct device *dev);
 extern void pm_generic_complete(struct device *dev);