Merge branch 'pm-core'

* pm-core:
  PM: runtime: Improve kerneldoc of pm_runtime_get_if_active()
  PM: runtime: Add kerneldoc comments to multiple helpers

2 files changed, 260 insertions, 12 deletions

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 9f62790f644c..8143210a5c54 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1085,24 +1085,26 @@ int __pm_runtime_resume(struct device *dev, int rpmflags)
 EXPORT_SYMBOL_GPL(__pm_runtime_resume);
 
 /**
- * pm_runtime_get_if_active - Conditionally bump up the device's usage counter.
+ * pm_runtime_get_if_active - Conditionally bump up device usage counter.
  * @dev: Device to handle.
+ * @ign_usage_count: Whether or not to look at the current usage counter value.
  *
- * Return -EINVAL if runtime PM is disabled for the device.
+ * Return -EINVAL if runtime PM is disabled for @dev.
  *
- * Otherwise, if the device's runtime PM status is RPM_ACTIVE and either
- * ign_usage_count is true or the device's usage_count is non-zero, increment
- * the counter and return 1. Otherwise return 0 without changing the counter.
+ * Otherwise, if the runtime PM status of @dev is %RPM_ACTIVE and either
+ * @ign_usage_count is %true or the runtime PM usage counter of @dev is not
+ * zero, increment the usage counter of @dev and return 1. Otherwise, return 0
+ * without changing the usage counter.
  *
- * If ign_usage_count is true, the function can be used to prevent suspending
- * the device when its runtime PM status is RPM_ACTIVE.
+ * If @ign_usage_count is %true, this function can be used to prevent suspending
+ * the device when its runtime PM status is %RPM_ACTIVE.
  *
- * If ign_usage_count is false, the function can be used to prevent suspending
- * the device when both its runtime PM status is RPM_ACTIVE and its usage_count
- * is non-zero.
+ * If @ign_usage_count is %false, this function can be used to prevent
+ * suspending the device when both its runtime PM status is %RPM_ACTIVE and its
+ * runtime PM usage counter is not zero.
  *
- * The caller is resposible for putting the device's usage count when ther
- * return value is greater than zero.
+ * The caller is resposible for decrementing the runtime PM usage counter of
+ * @dev after this function has returned a positive value for it.
  */
 int pm_runtime_get_if_active(struct device *dev, bool ign_usage_count)
 {
diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h
index 3dbc207bff53..6245caa18034 100644
--- a/include/linux/pm_runtime.h
+++ b/include/linux/pm_runtime.h
@@ -60,58 +60,151 @@ extern void pm_runtime_put_suppliers(struct device *dev);
 extern void pm_runtime_new_link(struct device *dev);
 extern void pm_runtime_drop_link(struct device *dev);
 
+/**
+ * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter.
+ * @dev: Target device.
+ *
+ * Increment the runtime PM usage counter of @dev if its runtime PM status is
+ * %RPM_ACTIVE and its runtime PM usage counter is greater than 0.
+ */
 static inline int pm_runtime_get_if_in_use(struct device *dev)
 {
 	return pm_runtime_get_if_active(dev, false);
 }
 
+/**
+ * pm_suspend_ignore_children - Set runtime PM behavior regarding children.
+ * @dev: Target device.
+ * @enable: Whether or not to ignore possible dependencies on children.
+ *
+ * The dependencies of @dev on its children will not be taken into account by
+ * the runtime PM framework going forward if @enable is %true, or they will
+ * be taken into account otherwise.
+ */
 static inline void pm_suspend_ignore_children(struct device *dev, bool enable)
 {
 	dev->power.ignore_children = enable;
 }
 
+/**
+ * pm_runtime_get_noresume - Bump up runtime PM usage counter of a device.
+ * @dev: Target device.
+ */
 static inline void pm_runtime_get_noresume(struct device *dev)
 {
 	atomic_inc(&dev->power.usage_count);
 }
 
+/**
+ * pm_runtime_put_noidle - Drop runtime PM usage counter of a device.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev unless it is 0 already.
+ */
 static inline void pm_runtime_put_noidle(struct device *dev)
 {
 	atomic_add_unless(&dev->power.usage_count, -1, 0);
 }
 
+/**
+ * pm_runtime_suspended - Check whether or not a device is runtime-suspended.
+ * @dev: Target device.
+ *
+ * Return %true if runtime PM is enabled for @dev and its runtime PM status is
+ * %RPM_SUSPENDED, or %false otherwise.
+ *
+ * Note that the return value of this function can only be trusted if it is
+ * called under the runtime PM lock of @dev or under conditions in which
+ * runtime PM cannot be either disabled or enabled for @dev and its runtime PM
+ * status cannot change.
+ */
 static inline bool pm_runtime_suspended(struct device *dev)
 {
 	return dev->power.runtime_status == RPM_SUSPENDED
 		&& !dev->power.disable_depth;
 }
 
+/**
+ * pm_runtime_active - Check whether or not a device is runtime-active.
+ * @dev: Target device.
+ *
+ * Return %true if runtime PM is enabled for @dev and its runtime PM status is
+ * %RPM_ACTIVE, or %false otherwise.
+ *
+ * Note that the return value of this function can only be trusted if it is
+ * called under the runtime PM lock of @dev or under conditions in which
+ * runtime PM cannot be either disabled or enabled for @dev and its runtime PM
+ * status cannot change.
+ */
 static inline bool pm_runtime_active(struct device *dev)
 {
 	return dev->power.runtime_status == RPM_ACTIVE
 		|| dev->power.disable_depth;
 }
 
+/**
+ * pm_runtime_status_suspended - Check if runtime PM status is "suspended".
+ * @dev: Target device.
+ *
+ * Return %true if the runtime PM status of @dev is %RPM_SUSPENDED, or %false
+ * otherwise, regardless of whether or not runtime PM has been enabled for @dev.
+ *
+ * Note that the return value of this function can only be trusted if it is
+ * called under the runtime PM lock of @dev or under conditions in which the
+ * runtime PM status of @dev cannot change.
+ */
 static inline bool pm_runtime_status_suspended(struct device *dev)
 {
 	return dev->power.runtime_status == RPM_SUSPENDED;
 }
 
+/**
+ * pm_runtime_enabled - Check if runtime PM is enabled.
+ * @dev: Target device.
+ *
+ * Return %true if runtime PM is enabled for @dev or %false otherwise.
+ *
+ * Note that the return value of this function can only be trusted if it is
+ * called under the runtime PM lock of @dev or under conditions in which
+ * runtime PM cannot be either disabled or enabled for @dev.
+ */
 static inline bool pm_runtime_enabled(struct device *dev)
 {
 	return !dev->power.disable_depth;
 }
 
+/**
+ * pm_runtime_has_no_callbacks - Check if runtime PM callbacks may be present.
+ * @dev: Target device.
+ *
+ * Return %true if @dev is a special device without runtime PM callbacks or
+ * %false otherwise.
+ */
 static inline bool pm_runtime_has_no_callbacks(struct device *dev)
 {
 	return dev->power.no_callbacks;
 }
 
+/**
+ * pm_runtime_mark_last_busy - Update the last access time of a device.
+ * @dev: Target device.
+ *
+ * Update the last access time of @dev used by the runtime PM autosuspend
+ * mechanism to the current time as returned by ktime_get_mono_fast_ns().
+ */
 static inline void pm_runtime_mark_last_busy(struct device *dev)
 {
 	WRITE_ONCE(dev->power.last_busy, ktime_get_mono_fast_ns());
 }
 
+/**
+ * pm_runtime_is_irq_safe - Check if runtime PM can work in interrupt context.
+ * @dev: Target device.
+ *
+ * Return %true if @dev has been marked as an "IRQ-safe" device (with respect
+ * to runtime PM), in which case its runtime PM callabcks can be expected to
+ * work correctly when invoked from interrupt handlers.
+ */
 static inline bool pm_runtime_is_irq_safe(struct device *dev)
 {
 	return dev->power.irq_safe;
@@ -191,97 +284,250 @@ static inline void pm_runtime_drop_link(struct device *dev) {}
 
 #endif /* !CONFIG_PM */
 
+/**
+ * pm_runtime_idle - Conditionally set up autosuspend of a device or suspend it.
+ * @dev: Target device.
+ *
+ * Invoke the "idle check" callback of @dev and, depending on its return value,
+ * set up autosuspend of @dev or suspend it (depending on whether or not
+ * autosuspend has been enabled for it).
+ */
 static inline int pm_runtime_idle(struct device *dev)
 {
 	return __pm_runtime_idle(dev, 0);
 }
 
+/**
+ * pm_runtime_suspend - Suspend a device synchronously.
+ * @dev: Target device.
+ */
 static inline int pm_runtime_suspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev, 0);
 }
 
+/**
+ * pm_runtime_autosuspend - Set up autosuspend of a device or suspend it.
+ * @dev: Target device.
+ *
+ * Set up autosuspend of @dev or suspend it (depending on whether or not
+ * autosuspend is enabled for it) without engaging its "idle check" callback.
+ */
 static inline int pm_runtime_autosuspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev, RPM_AUTO);
 }
 
+/**
+ * pm_runtime_resume - Resume a device synchronously.
+ * @dev: Target device.
+ */
 static inline int pm_runtime_resume(struct device *dev)
 {
 	return __pm_runtime_resume(dev, 0);
 }
 
+/**
+ * pm_request_idle - Queue up "idle check" execution for a device.
+ * @dev: Target device.
+ *
+ * Queue up a work item to run an equivalent of pm_runtime_idle() for @dev
+ * asynchronously.
+ */
 static inline int pm_request_idle(struct device *dev)
 {
 	return __pm_runtime_idle(dev, RPM_ASYNC);
 }
 
+/**
+ * pm_request_resume - Queue up runtime-resume of a device.
+ * @dev: Target device.
+ */
 static inline int pm_request_resume(struct device *dev)
 {
 	return __pm_runtime_resume(dev, RPM_ASYNC);
 }
 
+/**
+ * pm_request_autosuspend - Queue up autosuspend of a device.
+ * @dev: Target device.
+ *
+ * Queue up a work item to run an equivalent pm_runtime_autosuspend() for @dev
+ * asynchronously.
+ */
 static inline int pm_request_autosuspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev, RPM_ASYNC | RPM_AUTO);
 }
 
+/**
+ * pm_runtime_get - Bump up usage counter and queue up resume of a device.
+ * @dev: Target device.
+ *
+ * Bump up the runtime PM usage counter of @dev and queue up a work item to
+ * carry out runtime-resume of it.
+ */
 static inline int pm_runtime_get(struct device *dev)
 {
 	return __pm_runtime_resume(dev, RPM_GET_PUT | RPM_ASYNC);
 }
 
+/**
+ * pm_runtime_get_sync - Bump up usage counter of a device and resume it.
+ * @dev: Target device.
+ *
+ * Bump up the runtime PM usage counter of @dev and carry out runtime-resume of
+ * it synchronously.
+ *
+ * The possible return values of this function are the same as for
+ * pm_runtime_resume() and the runtime PM usage counter of @dev remains
+ * incremented in all cases, even if it returns an error code.
+ */
 static inline int pm_runtime_get_sync(struct device *dev)
 {
 	return __pm_runtime_resume(dev, RPM_GET_PUT);
 }
 
+/**
+ * pm_runtime_put - Drop device usage counter and queue up "idle check" if 0.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev and if it turns out to be
+ * equal to 0, queue up a work item for @dev like in pm_request_idle().
+ */
 static inline int pm_runtime_put(struct device *dev)
 {
 	return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC);
 }
 
+/**
+ * pm_runtime_put_autosuspend - Drop device usage counter and queue autosuspend if 0.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev and if it turns out to be
+ * equal to 0, queue up a work item for @dev like in pm_request_autosuspend().
+ */
 static inline int pm_runtime_put_autosuspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev,
 	    RPM_GET_PUT | RPM_ASYNC | RPM_AUTO);
 }
 
+/**
+ * pm_runtime_put_sync - Drop device usage counter and run "idle check" if 0.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev and if it turns out to be
+ * equal to 0, invoke the "idle check" callback of @dev and, depending on its
+ * return value, set up autosuspend of @dev or suspend it (depending on whether
+ * or not autosuspend has been enabled for it).
+ *
+ * The possible return values of this function are the same as for
+ * pm_runtime_idle() and the runtime PM usage counter of @dev remains
+ * decremented in all cases, even if it returns an error code.
+ */
 static inline int pm_runtime_put_sync(struct device *dev)
 {
 	return __pm_runtime_idle(dev, RPM_GET_PUT);
 }
 
+/**
+ * pm_runtime_put_sync_suspend - Drop device usage counter and suspend if 0.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev and if it turns out to be
+ * equal to 0, carry out runtime-suspend of @dev synchronously.
+ *
+ * The possible return values of this function are the same as for
+ * pm_runtime_suspend() and the runtime PM usage counter of @dev remains
+ * decremented in all cases, even if it returns an error code.
+ */
 static inline int pm_runtime_put_sync_suspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev, RPM_GET_PUT);
 }
 
+/**
+ * pm_runtime_put_sync_autosuspend - Drop device usage counter and autosuspend if 0.
+ * @dev: Target device.
+ *
+ * Decrement the runtime PM usage counter of @dev and if it turns out to be
+ * equal to 0, set up autosuspend of @dev or suspend it synchronously (depending
+ * on whether or not autosuspend has been enabled for it).
+ *
+ * The possible return values of this function are the same as for
+ * pm_runtime_autosuspend() and the runtime PM usage counter of @dev remains
+ * decremented in all cases, even if it returns an error code.
+ */
 static inline int pm_runtime_put_sync_autosuspend(struct device *dev)
 {
 	return __pm_runtime_suspend(dev, RPM_GET_PUT | RPM_AUTO);
 }
 
+/**
+ * pm_runtime_set_active - Set runtime PM status to "active".
+ * @dev: Target device.
+ *
+ * Set the runtime PM status of @dev to %RPM_ACTIVE and ensure that dependencies
+ * of it will be taken into account.
+ *
+ * It is not valid to call this function for devices with runtime PM enabled.
+ */
 static inline int pm_runtime_set_active(struct device *dev)
 {
 	return __pm_runtime_set_status(dev, RPM_ACTIVE);
 }
 
+/**
+ * pm_runtime_set_suspended - Set runtime PM status to "active".
+ * @dev: Target device.
+ *
+ * Set the runtime PM status of @dev to %RPM_SUSPENDED and ensure that
+ * dependencies of it will be taken into account.
+ *
+ * It is not valid to call this function for devices with runtime PM enabled.
+ */
 static inline int pm_runtime_set_suspended(struct device *dev)
 {
 	return __pm_runtime_set_status(dev, RPM_SUSPENDED);
 }
 
+/**
+ * pm_runtime_disable - Disable runtime PM for a device.
+ * @dev: Target device.
+ *
+ * Prevent the runtime PM framework from working with @dev (by incrementing its
+ * "blocking" counter).
+ *
+ * For each invocation of this function for @dev there must be a matching
+ * pm_runtime_enable() call in order for runtime PM to be enabled for it.
+ */
 static inline void pm_runtime_disable(struct device *dev)
 {
 	__pm_runtime_disable(dev, true);
 }
 
+/**
+ * pm_runtime_use_autosuspend - Allow autosuspend to be used for a device.
+ * @dev: Target device.
+ *
+ * Allow the runtime PM autosuspend mechanism to be used for @dev whenever
+ * requested (or "autosuspend" will be handled as direct runtime-suspend for
+ * it).
+ */
 static inline void pm_runtime_use_autosuspend(struct device *dev)
 {
 	__pm_runtime_use_autosuspend(dev, true);
 }
 
+/**
+ * pm_runtime_dont_use_autosuspend - Prevent autosuspend from being used.
+ * @dev: Target device.
+ *
+ * Prevent the runtime PM autosuspend mechanism from being used for @dev which
+ * means that "autosuspend" will be handled as direct runtime-suspend for it
+ * going forward.
+ */
 static inline void pm_runtime_dont_use_autosuspend(struct device *dev)
 {
 	__pm_runtime_use_autosuspend(dev, false);