===================================================================
@@ -463,6 +463,14 @@ struct dev_pm_info {
extern void update_pm_runtime_accounting(struct device *dev);
+/*
+ * Power domains provide callbacks that are executed during system suspend,
+ * hibernation, system resume and during runtime PM transitions along with
+ * subsystem-level and driver-level callbacks.
+ */
+struct dev_power_domain {
+ struct dev_pm_ops ops;
+};
/*
* The PM_EVENT_ messages are also used by drivers implementing the legacy
===================================================================
@@ -422,6 +422,7 @@ struct device {
void *platform_data; /* Platform specific data, device
core doesn't touch it */
struct dev_pm_info power;
+ struct dev_power_domain *pwr_domain;
#ifdef CONFIG_NUMA
int numa_node; /* NUMA node this device is close to */
===================================================================
@@ -168,6 +168,7 @@ static int rpm_check_suspend_allowed(str
static int rpm_idle(struct device *dev, int rpmflags)
{
int (*callback)(struct device *);
+ int (*domain_callback)(struct device *);
int retval;
retval = rpm_check_suspend_allowed(dev);
@@ -222,10 +223,19 @@ static int rpm_idle(struct device *dev,
else
callback = NULL;
- if (callback) {
+ if (dev->pwr_domain)
+ domain_callback = dev->pwr_domain->ops.runtime_idle;
+ else
+ domain_callback = NULL;
+
+ if (callback || domain_callback) {
spin_unlock_irq(&dev->power.lock);
- callback(dev);
+ if (domain_callback)
+ retval = domain_callback(dev);
+
+ if (!retval && callback)
+ callback(dev);
spin_lock_irq(&dev->power.lock);
}
@@ -390,6 +400,8 @@ static int rpm_suspend(struct device *de
else
pm_runtime_cancel_pending(dev);
} else {
+ if (dev->pwr_domain)
+ rpm_callback(dev->pwr_domain->ops.runtime_suspend, dev);
no_callback:
__update_runtime_status(dev, RPM_SUSPENDED);
pm_runtime_deactivate_timer(dev);
@@ -569,6 +581,9 @@ static int rpm_resume(struct device *dev
__update_runtime_status(dev, RPM_RESUMING);
+ if (dev->pwr_domain)
+ rpm_callback(dev->pwr_domain->ops.runtime_resume, dev);
+
if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
callback = dev->bus->pm->runtime_resume;
else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
===================================================================
@@ -423,6 +423,11 @@ static int device_resume_noirq(struct de
TRACE_DEVICE(dev);
TRACE_RESUME(0);
+ if (dev->pwr_domain) {
+ pm_dev_dbg(dev, state, "EARLY power domain ");
+ pm_noirq_op(dev, &dev->pwr_domain->ops, state);
+ }
+
if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "EARLY ");
error = pm_noirq_op(dev, dev->bus->pm, state);
@@ -518,6 +523,11 @@ static int device_resume(struct device *
dev->power.in_suspend = false;
+ if (dev->pwr_domain) {
+ pm_dev_dbg(dev, state, "power domain ");
+ pm_op(dev, &dev->pwr_domain->ops, state);
+ }
+
if (dev->bus) {
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "");
@@ -629,6 +639,11 @@ static void device_complete(struct devic
{
device_lock(dev);
+ if (dev->pwr_domain && dev->pwr_domain->ops.complete) {
+ pm_dev_dbg(dev, state, "completing power domain ");
+ dev->pwr_domain->ops.complete(dev);
+ }
+
if (dev->class && dev->class->pm && dev->class->pm->complete) {
pm_dev_dbg(dev, state, "completing class ");
dev->class->pm->complete(dev);
@@ -745,6 +760,13 @@ static int device_suspend_noirq(struct d
if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "LATE ");
error = pm_noirq_op(dev, dev->bus->pm, state);
+ if (error)
+ goto End;
+ }
+
+ if (dev->pwr_domain) {
+ pm_dev_dbg(dev, state, "LATE power domain ");
+ pm_noirq_op(dev, &dev->pwr_domain->ops, state);
}
End:
@@ -864,6 +886,13 @@ static int __device_suspend(struct devic
pm_dev_dbg(dev, state, "legacy ");
error = legacy_suspend(dev, state, dev->bus->suspend);
}
+ if (error)
+ goto End;
+ }
+
+ if (dev->pwr_domain) {
+ pm_dev_dbg(dev, state, "power domain ");
+ pm_op(dev, &dev->pwr_domain->ops, state);
}
End:
@@ -976,7 +1005,15 @@ static int device_prepare(struct device
pm_dev_dbg(dev, state, "preparing class ");
error = dev->class->pm->prepare(dev);
suspend_report_result(dev->class->pm->prepare, error);
+ if (error)
+ goto End;
+ }
+
+ if (dev->pwr_domain && dev->pwr_domain->ops.prepare) {
+ pm_dev_dbg(dev, state, "preparing power domain ");
+ dev->pwr_domain->ops.prepare(dev);
}
+
End:
device_unlock(dev);
===================================================================
@@ -1,6 +1,6 @@
Device Power Management
-Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+Copyright (c) 2010-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
Copyright (c) 2010 Alan Stern <stern@rowland.harvard.edu>
@@ -507,6 +507,49 @@ routines. Nevertheless, different callb
situation where it actually matters.
+Device Power Domains
+--------------------
+Sometimes devices share reference clocks or other power resources. In those
+cases it generally is not possible to put devices into low-power states
+individually. Instead, a set of devices sharing a power resource can be put
+into a low-power state together at the same time by turning off the shared
+power resource. Of course, they also need to be put into the full-power state
+together, by turning the shared power resource on. A set of devices with this
+property is often referred to as a power domain.
+
+Support for power domains is provided through the pwr_domain field of struct
+device. This field is a pointer to an object of type struct dev_power_domain,
+defined in include/linux/pm.h, providing a set of power management callbacks
+analogous to the subsystem-level and device driver callbacks that are executed
+for the given device during all power transitions, in addition to the respective
+subsystem-level callbacks. Specifically, the power domain "suspend" callbacks
+(i.e. ->runtime_suspend(), ->suspend(), ->freeze(), ->poweroff(), etc.) are
+executed after the analogous subsystem-level callbacks, while the power domain
+"resume" callbacks (i.e. ->runtime_resume(), ->resume(), ->thaw(), ->restore,
+etc.) are executed before the analogous subsystem-level callbacks. Error codes
+returned by the "suspend" and "resume" power domain callbacks are ignored.
+
+Power domain ->runtime_idle() callback is executed before the subsystem-level
+->runtime_idle() callback and the result returned by it is not ignored. Namely,
+if it returns error code, the subsystem-level ->runtime_idle() callback will not
+be called and the helper function rpm_idle() executing it will return error
+code. This mechanism is intended to help platforms where saving device state
+is a time consuming operation and should only be carried out if all devices
+in the power domain are idle, before turning off the shared power resource(s).
+Namely, the power domain ->runtime_idle() callback may return error code until
+the pm_runtime_idle() helper (or its asychronous version) has been called for
+all devices in the power domain (it is recommended that the returned error code
+be -EBUSY in those cases), preventing the subsystem-level ->runtime_idle()
+callback from being run prematurely.
+
+The support for device power domains is only relevant to platforms needing to
+use the same subsystem-level (e.g. platform bus type) and device driver power
+management callbacks in many different power domain configurations and wanting
+to avoid incorporating the support for power domains into the subsystem-level
+callbacks. The other platforms need not implement it or take it into account
+in any way.
+
+
System Devices
--------------
System devices (sysdevs) follow a slightly different API, which can be found in