blob: 5a01ecef4af3600da40b8e458bc670d1223d2fbe [file] [log] [blame]
/*
* drivers/base/power/runtime.c - Helper functions for device run-time PM
*
* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/sched.h>
#include <linux/pm_runtime.h>
#include <linux/jiffies.h>
static int __pm_runtime_resume(struct device *dev, bool from_wq);
static int __pm_request_idle(struct device *dev);
static int __pm_request_resume(struct device *dev);
/**
* pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
* @dev: Device to handle.
*/
static void pm_runtime_deactivate_timer(struct device *dev)
{
if (dev->power.timer_expires > 0) {
del_timer(&dev->power.suspend_timer);
dev->power.timer_expires = 0;
}
}
/**
* pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
* @dev: Device to handle.
*/
static void pm_runtime_cancel_pending(struct device *dev)
{
pm_runtime_deactivate_timer(dev);
/*
* In case there's a request pending, make sure its work function will
* return without doing anything.
*/
dev->power.request = RPM_REQ_NONE;
}
/**
* __pm_runtime_idle - Notify device bus type if the device can be suspended.
* @dev: Device to notify the bus type about.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
static int __pm_runtime_idle(struct device *dev)
__releases(&dev->power.lock) __acquires(&dev->power.lock)
{
int retval = 0;
if (dev->power.runtime_error)
retval = -EINVAL;
else if (dev->power.idle_notification)
retval = -EINPROGRESS;
else if (atomic_read(&dev->power.usage_count) > 0
|| dev->power.disable_depth > 0
|| dev->power.runtime_status != RPM_ACTIVE)
retval = -EAGAIN;
else if (!pm_children_suspended(dev))
retval = -EBUSY;
if (retval)
goto out;
if (dev->power.request_pending) {
/*
* If an idle notification request is pending, cancel it. Any
* other pending request takes precedence over us.
*/
if (dev->power.request == RPM_REQ_IDLE) {
dev->power.request = RPM_REQ_NONE;
} else if (dev->power.request != RPM_REQ_NONE) {
retval = -EAGAIN;
goto out;
}
}
dev->power.idle_notification = true;
if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) {
spin_unlock_irq(&dev->power.lock);
dev->bus->pm->runtime_idle(dev);
spin_lock_irq(&dev->power.lock);
}
dev->power.idle_notification = false;
wake_up_all(&dev->power.wait_queue);
out:
return retval;
}
/**
* pm_runtime_idle - Notify device bus type if the device can be suspended.
* @dev: Device to notify the bus type about.
*/
int pm_runtime_idle(struct device *dev)
{
int retval;
spin_lock_irq(&dev->power.lock);
retval = __pm_runtime_idle(dev);
spin_unlock_irq(&dev->power.lock);
return retval;
}
EXPORT_SYMBOL_GPL(pm_runtime_idle);
/**
* __pm_runtime_suspend - Carry out run-time suspend of given device.
* @dev: Device to suspend.
* @from_wq: If set, the function has been called via pm_wq.
*
* Check if the device can be suspended and run the ->runtime_suspend() callback
* provided by its bus type. If another suspend has been started earlier, wait
* for it to finish. If an idle notification or suspend request is pending or
* scheduled, cancel it.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
int __pm_runtime_suspend(struct device *dev, bool from_wq)
__releases(&dev->power.lock) __acquires(&dev->power.lock)
{
struct device *parent = NULL;
bool notify = false;
int retval = 0;
dev_dbg(dev, "__pm_runtime_suspend()%s!\n",
from_wq ? " from workqueue" : "");
repeat:
if (dev->power.runtime_error) {
retval = -EINVAL;
goto out;
}
/* Pending resume requests take precedence over us. */
if (dev->power.request_pending
&& dev->power.request == RPM_REQ_RESUME) {
retval = -EAGAIN;
goto out;
}
/* Other scheduled or pending requests need to be canceled. */
pm_runtime_cancel_pending(dev);
if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
else if (dev->power.runtime_status == RPM_RESUMING
|| dev->power.disable_depth > 0
|| atomic_read(&dev->power.usage_count) > 0)
retval = -EAGAIN;
else if (!pm_children_suspended(dev))
retval = -EBUSY;
if (retval)
goto out;
if (dev->power.runtime_status == RPM_SUSPENDING) {
DEFINE_WAIT(wait);
if (from_wq) {
retval = -EINPROGRESS;
goto out;
}
/* Wait for the other suspend running in parallel with us. */
for (;;) {
prepare_to_wait(&dev->power.wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (dev->power.runtime_status != RPM_SUSPENDING)
break;
spin_unlock_irq(&dev->power.lock);
schedule();
spin_lock_irq(&dev->power.lock);
}
finish_wait(&dev->power.wait_queue, &wait);
goto repeat;
}
dev->power.runtime_status = RPM_SUSPENDING;
dev->power.deferred_resume = false;
if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) {
spin_unlock_irq(&dev->power.lock);
retval = dev->bus->pm->runtime_suspend(dev);
spin_lock_irq(&dev->power.lock);
dev->power.runtime_error = retval;
} else {
retval = -ENOSYS;
}
if (retval) {
dev->power.runtime_status = RPM_ACTIVE;
pm_runtime_cancel_pending(dev);
if (retval == -EAGAIN || retval == -EBUSY) {
notify = true;
dev->power.runtime_error = 0;
}
} else {
dev->power.runtime_status = RPM_SUSPENDED;
if (dev->parent) {
parent = dev->parent;
atomic_add_unless(&parent->power.child_count, -1, 0);
}
}
wake_up_all(&dev->power.wait_queue);
if (dev->power.deferred_resume) {
__pm_runtime_resume(dev, false);
retval = -EAGAIN;
goto out;
}
if (notify)
__pm_runtime_idle(dev);
if (parent && !parent->power.ignore_children) {
spin_unlock_irq(&dev->power.lock);
pm_request_idle(parent);
spin_lock_irq(&dev->power.lock);
}
out:
dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval);
return retval;
}
/**
* pm_runtime_suspend - Carry out run-time suspend of given device.
* @dev: Device to suspend.
*/
int pm_runtime_suspend(struct device *dev)
{
int retval;
spin_lock_irq(&dev->power.lock);
retval = __pm_runtime_suspend(dev, false);
spin_unlock_irq(&dev->power.lock);
return retval;
}
EXPORT_SYMBOL_GPL(pm_runtime_suspend);
/**
* __pm_runtime_resume - Carry out run-time resume of given device.
* @dev: Device to resume.
* @from_wq: If set, the function has been called via pm_wq.
*
* Check if the device can be woken up and run the ->runtime_resume() callback
* provided by its bus type. If another resume has been started earlier, wait
* for it to finish. If there's a suspend running in parallel with this
* function, wait for it to finish and resume the device. Cancel any scheduled
* or pending requests.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
int __pm_runtime_resume(struct device *dev, bool from_wq)
__releases(&dev->power.lock) __acquires(&dev->power.lock)
{
struct device *parent = NULL;
int retval = 0;
dev_dbg(dev, "__pm_runtime_resume()%s!\n",
from_wq ? " from workqueue" : "");
repeat:
if (dev->power.runtime_error) {
retval = -EINVAL;
goto out;
}
pm_runtime_cancel_pending(dev);
if (dev->power.runtime_status == RPM_ACTIVE)
retval = 1;
else if (dev->power.disable_depth > 0)
retval = -EAGAIN;
if (retval)
goto out;
if (dev->power.runtime_status == RPM_RESUMING
|| dev->power.runtime_status == RPM_SUSPENDING) {
DEFINE_WAIT(wait);
if (from_wq) {
if (dev->power.runtime_status == RPM_SUSPENDING)
dev->power.deferred_resume = true;
retval = -EINPROGRESS;
goto out;
}
/* Wait for the operation carried out in parallel with us. */
for (;;) {
prepare_to_wait(&dev->power.wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (dev->power.runtime_status != RPM_RESUMING
&& dev->power.runtime_status != RPM_SUSPENDING)
break;
spin_unlock_irq(&dev->power.lock);
schedule();
spin_lock_irq(&dev->power.lock);
}
finish_wait(&dev->power.wait_queue, &wait);
goto repeat;
}
if (!parent && dev->parent) {
/*
* Increment the parent's resume counter and resume it if
* necessary.
*/
parent = dev->parent;
spin_unlock(&dev->power.lock);
pm_runtime_get_noresume(parent);
spin_lock(&parent->power.lock);
/*
* We can resume if the parent's run-time PM is disabled or it
* is set to ignore children.
*/
if (!parent->power.disable_depth
&& !parent->power.ignore_children) {
__pm_runtime_resume(parent, false);
if (parent->power.runtime_status != RPM_ACTIVE)
retval = -EBUSY;
}
spin_unlock(&parent->power.lock);
spin_lock(&dev->power.lock);
if (retval)
goto out;
goto repeat;
}
dev->power.runtime_status = RPM_RESUMING;
if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) {
spin_unlock_irq(&dev->power.lock);
retval = dev->bus->pm->runtime_resume(dev);
spin_lock_irq(&dev->power.lock);
dev->power.runtime_error = retval;
} else {
retval = -ENOSYS;
}
if (retval) {
dev->power.runtime_status = RPM_SUSPENDED;
pm_runtime_cancel_pending(dev);
} else {
dev->power.runtime_status = RPM_ACTIVE;
if (parent)
atomic_inc(&parent->power.child_count);
}
wake_up_all(&dev->power.wait_queue);
if (!retval)
__pm_request_idle(dev);
out:
if (parent) {
spin_unlock_irq(&dev->power.lock);
pm_runtime_put(parent);
spin_lock_irq(&dev->power.lock);
}
dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval);
return retval;
}
/**
* pm_runtime_resume - Carry out run-time resume of given device.
* @dev: Device to suspend.
*/
int pm_runtime_resume(struct device *dev)
{
int retval;
spin_lock_irq(&dev->power.lock);
retval = __pm_runtime_resume(dev, false);
spin_unlock_irq(&dev->power.lock);
return retval;
}
EXPORT_SYMBOL_GPL(pm_runtime_resume);
/**
* pm_runtime_work - Universal run-time PM work function.
* @work: Work structure used for scheduling the execution of this function.
*
* Use @work to get the device object the work is to be done for, determine what
* is to be done and execute the appropriate run-time PM function.
*/
static void pm_runtime_work(struct work_struct *work)
{
struct device *dev = container_of(work, struct device, power.work);
enum rpm_request req;
spin_lock_irq(&dev->power.lock);
if (!dev->power.request_pending)
goto out;
req = dev->power.request;
dev->power.request = RPM_REQ_NONE;
dev->power.request_pending = false;
switch (req) {
case RPM_REQ_NONE:
break;
case RPM_REQ_IDLE:
__pm_runtime_idle(dev);
break;
case RPM_REQ_SUSPEND:
__pm_runtime_suspend(dev, true);
break;
case RPM_REQ_RESUME:
__pm_runtime_resume(dev, true);
break;
}
out:
spin_unlock_irq(&dev->power.lock);
}
/**
* __pm_request_idle - Submit an idle notification request for given device.
* @dev: Device to handle.
*
* Check if the device's run-time PM status is correct for suspending the device
* and queue up a request to run __pm_runtime_idle() for it.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
static int __pm_request_idle(struct device *dev)
{
int retval = 0;
if (dev->power.runtime_error)
retval = -EINVAL;
else if (atomic_read(&dev->power.usage_count) > 0
|| dev->power.disable_depth > 0
|| dev->power.runtime_status == RPM_SUSPENDED
|| dev->power.runtime_status == RPM_SUSPENDING)
retval = -EAGAIN;
else if (!pm_children_suspended(dev))
retval = -EBUSY;
if (retval)
return retval;
if (dev->power.request_pending) {
/* Any requests other then RPM_REQ_IDLE take precedence. */
if (dev->power.request == RPM_REQ_NONE)
dev->power.request = RPM_REQ_IDLE;
else if (dev->power.request != RPM_REQ_IDLE)
retval = -EAGAIN;
return retval;
}
dev->power.request = RPM_REQ_IDLE;
dev->power.request_pending = true;
queue_work(pm_wq, &dev->power.work);
return retval;
}
/**
* pm_request_idle - Submit an idle notification request for given device.
* @dev: Device to handle.
*/
int pm_request_idle(struct device *dev)
{
unsigned long flags;
int retval;
spin_lock_irqsave(&dev->power.lock, flags);
retval = __pm_request_idle(dev);
spin_unlock_irqrestore(&dev->power.lock, flags);
return retval;
}
EXPORT_SYMBOL_GPL(pm_request_idle);
/**
* __pm_request_suspend - Submit a suspend request for given device.
* @dev: Device to suspend.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
static int __pm_request_suspend(struct device *dev)
{
int retval = 0;
if (dev->power.runtime_error)
return -EINVAL;
if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
else if (atomic_read(&dev->power.usage_count) > 0
|| dev->power.disable_depth > 0)
retval = -EAGAIN;
else if (dev->power.runtime_status == RPM_SUSPENDING)
retval = -EINPROGRESS;
else if (!pm_children_suspended(dev))
retval = -EBUSY;
if (retval < 0)
return retval;
pm_runtime_deactivate_timer(dev);
if (dev->power.request_pending) {
/*
* Pending resume requests take precedence over us, but we can
* overtake any other pending request.
*/
if (dev->power.request == RPM_REQ_RESUME)
retval = -EAGAIN;
else if (dev->power.request != RPM_REQ_SUSPEND)
dev->power.request = retval ?
RPM_REQ_NONE : RPM_REQ_SUSPEND;
return retval;
} else if (retval) {
return retval;
}
dev->power.request = RPM_REQ_SUSPEND;
dev->power.request_pending = true;
queue_work(pm_wq, &dev->power.work);
return 0;
}
/**
* pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
* @data: Device pointer passed by pm_schedule_suspend().
*
* Check if the time is right and execute __pm_request_suspend() in that case.
*/
static void pm_suspend_timer_fn(unsigned long data)
{
struct device *dev = (struct device *)data;
unsigned long flags;
unsigned long expires;
spin_lock_irqsave(&dev->power.lock, flags);
expires = dev->power.timer_expires;
/* If 'expire' is after 'jiffies' we've been called too early. */
if (expires > 0 && !time_after(expires, jiffies)) {
dev->power.timer_expires = 0;
__pm_request_suspend(dev);
}
spin_unlock_irqrestore(&dev->power.lock, flags);
}
/**
* pm_schedule_suspend - Set up a timer to submit a suspend request in future.
* @dev: Device to suspend.
* @delay: Time to wait before submitting a suspend request, in milliseconds.
*/
int pm_schedule_suspend(struct device *dev, unsigned int delay)
{
unsigned long flags;
int retval = 0;
spin_lock_irqsave(&dev->power.lock, flags);
if (dev->power.runtime_error) {
retval = -EINVAL;
goto out;
}
if (!delay) {
retval = __pm_request_suspend(dev);
goto out;
}
pm_runtime_deactivate_timer(dev);
if (dev->power.request_pending) {
/*
* Pending resume requests take precedence over us, but any
* other pending requests have to be canceled.
*/
if (dev->power.request == RPM_REQ_RESUME) {
retval = -EAGAIN;
goto out;
}
dev->power.request = RPM_REQ_NONE;
}
if (dev->power.runtime_status == RPM_SUSPENDED)
retval = 1;
else if (dev->power.runtime_status == RPM_SUSPENDING)
retval = -EINPROGRESS;
else if (atomic_read(&dev->power.usage_count) > 0
|| dev->power.disable_depth > 0)
retval = -EAGAIN;
else if (!pm_children_suspended(dev))
retval = -EBUSY;
if (retval)
goto out;
dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
if (!dev->power.timer_expires)
dev->power.timer_expires = 1;
mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
out:
spin_unlock_irqrestore(&dev->power.lock, flags);
return retval;
}
EXPORT_SYMBOL_GPL(pm_schedule_suspend);
/**
* pm_request_resume - Submit a resume request for given device.
* @dev: Device to resume.
*
* This function must be called under dev->power.lock with interrupts disabled.
*/
static int __pm_request_resume(struct device *dev)
{
int retval = 0;
if (dev->power.runtime_error)
return -EINVAL;
if (dev->power.runtime_status == RPM_ACTIVE)
retval = 1;
else if (dev->power.runtime_status == RPM_RESUMING)
retval = -EINPROGRESS;
else if (dev->power.disable_depth > 0)
retval = -EAGAIN;
if (retval < 0)
return retval;
pm_runtime_deactivate_timer(dev);
if (dev->power.runtime_status == RPM_SUSPENDING) {
dev->power.deferred_resume = true;
return retval;
}
if (dev->power.request_pending) {
/* If non-resume request is pending, we can overtake it. */
dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME;
return retval;
}
if (retval)
return retval;
dev->power.request = RPM_REQ_RESUME;
dev->power.request_pending = true;
queue_work(pm_wq, &dev->power.work);
return retval;
}
/**
* pm_request_resume - Submit a resume request for given device.
* @dev: Device to resume.
*/
int pm_request_resume(struct device *dev)
{
unsigned long flags;
int retval;
spin_lock_irqsave(&dev->power.lock, flags);
retval = __pm_request_resume(dev);
spin_unlock_irqrestore(&dev->power.lock, flags);
return retval;
}
EXPORT_SYMBOL_GPL(pm_request_resume);
/**
* __pm_runtime_get - Reference count a device and wake it up, if necessary.
* @dev: Device to handle.
* @sync: If set and the device is suspended, resume it synchronously.
*
* Increment the usage count of the device and if it was zero previously,
* resume it or submit a resume request for it, depending on the value of @sync.
*/
int __pm_runtime_get(struct device *dev, bool sync)
{
int retval = 1;
if (atomic_add_return(1, &dev->power.usage_count) == 1)
retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev);
return retval;
}
EXPORT_SYMBOL_GPL(__pm_runtime_get);
/**
* __pm_runtime_put - Decrement the device's usage counter and notify its bus.
* @dev: Device to handle.
* @sync: If the device's bus type is to be notified, do that synchronously.
*
* Decrement the usage count of the device and if it reaches zero, carry out a
* synchronous idle notification or submit an idle notification request for it,
* depending on the value of @sync.
*/
int __pm_runtime_put(struct device *dev, bool sync)
{
int retval = 0;
if (atomic_dec_and_test(&dev->power.usage_count))
retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev);
return retval;
}
EXPORT_SYMBOL_GPL(__pm_runtime_put);
/**
* __pm_runtime_set_status - Set run-time PM status of a device.
* @dev: Device to handle.
* @status: New run-time PM status of the device.
*
* If run-time PM of the device is disabled or its power.runtime_error field is
* different from zero, the status may be changed either to RPM_ACTIVE, or to
* RPM_SUSPENDED, as long as that reflects the actual state of the device.
* However, if the device has a parent and the parent is not active, and the
* parent's power.ignore_children flag is unset, the device's status cannot be
* set to RPM_ACTIVE, so -EBUSY is returned in that case.
*
* If successful, __pm_runtime_set_status() clears the power.runtime_error field
* and the device parent's counter of unsuspended children is modified to
* reflect the new status. If the new status is RPM_SUSPENDED, an idle
* notification request for the parent is submitted.
*/
int __pm_runtime_set_status(struct device *dev, unsigned int status)
{
struct device *parent = dev->parent;
unsigned long flags;
bool notify_parent = false;
int error = 0;
if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
return -EINVAL;
spin_lock_irqsave(&dev->power.lock, flags);
if (!dev->power.runtime_error && !dev->power.disable_depth) {
error = -EAGAIN;
goto out;
}
if (dev->power.runtime_status == status)
goto out_set;
if (status == RPM_SUSPENDED) {
/* It always is possible to set the status to 'suspended'. */
if (parent) {
atomic_add_unless(&parent->power.child_count, -1, 0);
notify_parent = !parent->power.ignore_children;
}
goto out_set;
}
if (parent) {
spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
/*
* It is invalid to put an active child under a parent that is
* not active, has run-time PM enabled and the
* 'power.ignore_children' flag unset.
*/
if (!parent->power.disable_depth
&& !parent->power.ignore_children
&& parent->power.runtime_status != RPM_ACTIVE)
error = -EBUSY;
else if (dev->power.runtime_status == RPM_SUSPENDED)
atomic_inc(&parent->power.child_count);
spin_unlock(&parent->power.lock);
if (error)
goto out;
}
out_set:
dev->power.runtime_status = status;
dev->power.runtime_error = 0;
out:
spin_unlock_irqrestore(&dev->power.lock, flags);
if (notify_parent)
pm_request_idle(parent);
return error;
}
EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
/**
* __pm_runtime_barrier - Cancel pending requests and wait for completions.
* @dev: Device to handle.
*
* Flush all pending requests for the device from pm_wq and wait for all
* run-time PM operations involving the device in progress to complete.
*
* Should be called under dev->power.lock with interrupts disabled.
*/
static void __pm_runtime_barrier(struct device *dev)
{
pm_runtime_deactivate_timer(dev);
if (dev->power.request_pending) {
dev->power.request = RPM_REQ_NONE;
spin_unlock_irq(&dev->power.lock);
cancel_work_sync(&dev->power.work);
spin_lock_irq(&dev->power.lock);
dev->power.request_pending = false;
}
if (dev->power.runtime_status == RPM_SUSPENDING
|| dev->power.runtime_status == RPM_RESUMING
|| dev->power.idle_notification) {
DEFINE_WAIT(wait);
/* Suspend, wake-up or idle notification in progress. */
for (;;) {
prepare_to_wait(&dev->power.wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (dev->power.runtime_status != RPM_SUSPENDING
&& dev->power.runtime_status != RPM_RESUMING
&& !dev->power.idle_notification)
break;
spin_unlock_irq(&dev->power.lock);
schedule();
spin_lock_irq(&dev->power.lock);
}
finish_wait(&dev->power.wait_queue, &wait);
}
}
/**
* pm_runtime_barrier - Flush pending requests and wait for completions.
* @dev: Device to handle.
*
* Prevent the device from being suspended by incrementing its usage counter and
* if there's a pending resume request for the device, wake the device up.
* Next, make sure that all pending requests for the device have been flushed
* from pm_wq and wait for all run-time PM operations involving the device in
* progress to complete.
*
* Return value:
* 1, if there was a resume request pending and the device had to be woken up,
* 0, otherwise
*/
int pm_runtime_barrier(struct device *dev)
{
int retval = 0;
pm_runtime_get_noresume(dev);
spin_lock_irq(&dev->power.lock);
if (dev->power.request_pending
&& dev->power.request == RPM_REQ_RESUME) {
__pm_runtime_resume(dev, false);
retval = 1;
}
__pm_runtime_barrier(dev);
spin_unlock_irq(&dev->power.lock);
pm_runtime_put_noidle(dev);
return retval;
}
EXPORT_SYMBOL_GPL(pm_runtime_barrier);
/**
* __pm_runtime_disable - Disable run-time PM of a device.
* @dev: Device to handle.
* @check_resume: If set, check if there's a resume request for the device.
*
* Increment power.disable_depth for the device and if was zero previously,
* cancel all pending run-time PM requests for the device and wait for all
* operations in progress to complete. The device can be either active or
* suspended after its run-time PM has been disabled.
*
* If @check_resume is set and there's a resume request pending when
* __pm_runtime_disable() is called and power.disable_depth is zero, the
* function will wake up the device before disabling its run-time PM.
*/
void __pm_runtime_disable(struct device *dev, bool check_resume)
{
spin_lock_irq(&dev->power.lock);
if (dev->power.disable_depth > 0) {
dev->power.disable_depth++;
goto out;
}
/*
* Wake up the device if there's a resume request pending, because that
* means there probably is some I/O to process and disabling run-time PM
* shouldn't prevent the device from processing the I/O.
*/
if (check_resume && dev->power.request_pending
&& dev->power.request == RPM_REQ_RESUME) {
/*
* Prevent suspends and idle notifications from being carried
* out after we have woken up the device.
*/
pm_runtime_get_noresume(dev);
__pm_runtime_resume(dev, false);
pm_runtime_put_noidle(dev);
}
if (!dev->power.disable_depth++)
__pm_runtime_barrier(dev);
out:
spin_unlock_irq(&dev->power.lock);
}
EXPORT_SYMBOL_GPL(__pm_runtime_disable);
/**
* pm_runtime_enable - Enable run-time PM of a device.
* @dev: Device to handle.
*/
void pm_runtime_enable(struct device *dev)
{
unsigned long flags;
spin_lock_irqsave(&dev->power.lock, flags);
if (dev->power.disable_depth > 0)
dev->power.disable_depth--;
else
dev_warn(dev, "Unbalanced %s!\n", __func__);
spin_unlock_irqrestore(&dev->power.lock, flags);
}
EXPORT_SYMBOL_GPL(pm_runtime_enable);
/**
* pm_runtime_init - Initialize run-time PM fields in given device object.
* @dev: Device object to initialize.
*/
void pm_runtime_init(struct device *dev)
{
spin_lock_init(&dev->power.lock);
dev->power.runtime_status = RPM_SUSPENDED;
dev->power.idle_notification = false;
dev->power.disable_depth = 1;
atomic_set(&dev->power.usage_count, 0);
dev->power.runtime_error = 0;
atomic_set(&dev->power.child_count, 0);
pm_suspend_ignore_children(dev, false);
dev->power.request_pending = false;
dev->power.request = RPM_REQ_NONE;
dev->power.deferred_resume = false;
INIT_WORK(&dev->power.work, pm_runtime_work);
dev->power.timer_expires = 0;
setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
(unsigned long)dev);
init_waitqueue_head(&dev->power.wait_queue);
}
/**
* pm_runtime_remove - Prepare for removing a device from device hierarchy.
* @dev: Device object being removed from device hierarchy.
*/
void pm_runtime_remove(struct device *dev)
{
__pm_runtime_disable(dev, false);
/* Change the status back to 'suspended' to match the initial status. */
if (dev->power.runtime_status == RPM_ACTIVE)
pm_runtime_set_suspended(dev);
}