Commit 5980bb3e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Provide generic subsystem-level callbacks
  PM / Runtime: Document power.runtime_auto and related functions
parents 68ae6b5c d690b2cd
......@@ -224,6 +224,12 @@ defined in include/linux/pm.h:
RPM_SUSPENDED, which means that each device is initially regarded by the
PM core as 'suspended', regardless of its real hardware status
unsigned int runtime_auto;
- if set, indicates that the user space has allowed the device driver to
power manage the device at run time via the /sys/devices/.../power/control
interface; it may only be modified with the help of the pm_runtime_allow()
and pm_runtime_forbid() helper functions
All of the above fields are members of the 'power' member of 'struct device'.
4. Run-time PM Device Helper Functions
......@@ -329,6 +335,20 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
'power.runtime_error' is set or 'power.disable_depth' is greater than
zero)
bool pm_runtime_suspended(struct device *dev);
- return true if the device's runtime PM status is 'suspended', or false
otherwise
void pm_runtime_allow(struct device *dev);
- set the power.runtime_auto flag for the device and decrease its usage
counter (used by the /sys/devices/.../power/control interface to
effectively allow the device to be power managed at run time)
void pm_runtime_forbid(struct device *dev);
- unset the power.runtime_auto flag for the device and increase its usage
counter (used by the /sys/devices/.../power/control interface to
effectively prevent the device from being power managed at run time)
It is safe to execute the following helper functions from interrupt context:
pm_request_idle()
......@@ -382,6 +402,18 @@ may be desirable to suspend the device as soon as ->probe() or ->remove() has
finished, so the PM core uses pm_runtime_idle_sync() to invoke the
subsystem-level idle callback for the device at that time.
The user space can effectively disallow the driver of the device to power manage
it at run time by changing the value of its /sys/devices/.../power/control
attribute to "on", which causes pm_runtime_forbid() to be called. In principle,
this mechanism may also be used by the driver to effectively turn off the
run-time power management of the device until the user space turns it on.
Namely, during the initialization the driver can make sure that the run-time PM
status of the device is 'active' and call pm_runtime_forbid(). It should be
noted, however, that if the user space has already intentionally changed the
value of /sys/devices/.../power/control to "auto" to allow the driver to power
manage the device at run time, the driver may confuse it by using
pm_runtime_forbid() this way.
6. Run-time PM and System Sleep
Run-time PM and system sleep (i.e., system suspend and hibernation, also known
......@@ -431,3 +463,64 @@ The PM core always increments the run-time usage counter before calling the
->prepare() callback and decrements it after calling the ->complete() callback.
Hence disabling run-time PM temporarily like this will not cause any run-time
suspend callbacks to be lost.
7. Generic subsystem callbacks
Subsystems may wish to conserve code space by using the set of generic power
management callbacks provided by the PM core, defined in
driver/base/power/generic_ops.c:
int pm_generic_runtime_idle(struct device *dev);
- invoke the ->runtime_idle() callback provided by the driver of this
device, if defined, and call pm_runtime_suspend() for this device if the
return value is 0 or the callback is not defined
int pm_generic_runtime_suspend(struct device *dev);
- invoke the ->runtime_suspend() callback provided by the driver of this
device and return its result, or return -EINVAL if not defined
int pm_generic_runtime_resume(struct device *dev);
- invoke the ->runtime_resume() callback provided by the driver of this
device and return its result, or return -EINVAL if not defined
int pm_generic_suspend(struct device *dev);
- if the device has not been suspended at run time, invoke the ->suspend()
callback provided by its driver and return its result, or return 0 if not
defined
int pm_generic_resume(struct device *dev);
- invoke the ->resume() callback provided by the driver of this device and,
if successful, change the device's runtime PM status to 'active'
int pm_generic_freeze(struct device *dev);
- if the device has not been suspended at run time, invoke the ->freeze()
callback provided by its driver and return its result, or return 0 if not
defined
int pm_generic_thaw(struct device *dev);
- if the device has not been suspended at run time, invoke the ->thaw()
callback provided by its driver and return its result, or return 0 if not
defined
int pm_generic_poweroff(struct device *dev);
- if the device has not been suspended at run time, invoke the ->poweroff()
callback provided by its driver and return its result, or return 0 if not
defined
int pm_generic_restore(struct device *dev);
- invoke the ->restore() callback provided by the driver of this device and,
if successful, change the device's runtime PM status to 'active'
These functions can be assigned to the ->runtime_idle(), ->runtime_suspend(),
->runtime_resume(), ->suspend(), ->resume(), ->freeze(), ->thaw(), ->poweroff(),
or ->restore() callback pointers in the subsystem-level dev_pm_ops structures.
If a subsystem wishes to use all of them at the same time, it can simply assign
the GENERIC_SUBSYS_PM_OPS macro, defined in include/linux/pm.h, to its
dev_pm_ops structure pointer.
Device drivers that wish to use the same function as a system suspend, freeze,
poweroff and run-time suspend callback, and similarly for system resume, thaw,
restore, and run-time resume, can achieve this with the help of the
UNIVERSAL_DEV_PM_OPS macro defined in include/linux/pm.h (possibly setting its
last argument to NULL).
obj-$(CONFIG_PM) += sysfs.o
obj-$(CONFIG_PM_SLEEP) += main.o
obj-$(CONFIG_PM_RUNTIME) += runtime.o
obj-$(CONFIG_PM_OPS) += generic_ops.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
......
/*
* drivers/base/power/generic_ops.c - Generic PM callbacks for subsystems
*
* Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
* This file is released under the GPLv2.
*/
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#ifdef CONFIG_PM_RUNTIME
/**
* pm_generic_runtime_idle - Generic runtime idle callback for subsystems.
* @dev: Device to handle.
*
* If PM operations are defined for the @dev's driver and they include
* ->runtime_idle(), execute it and return its error code, if nonzero.
* Otherwise, execute pm_runtime_suspend() for the device and return 0.
*/
int pm_generic_runtime_idle(struct device *dev)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pm && pm->runtime_idle) {
int ret = pm->runtime_idle(dev);
if (ret)
return ret;
}
pm_runtime_suspend(dev);
return 0;
}
EXPORT_SYMBOL_GPL(pm_generic_runtime_idle);
/**
* pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems.
* @dev: Device to suspend.
*
* If PM operations are defined for the @dev's driver and they include
* ->runtime_suspend(), execute it and return its error code. Otherwise,
* return -EINVAL.
*/
int pm_generic_runtime_suspend(struct device *dev)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int ret;
ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : -EINVAL;
return ret;
}
EXPORT_SYMBOL_GPL(pm_generic_runtime_suspend);
/**
* pm_generic_runtime_resume - Generic runtime resume callback for subsystems.
* @dev: Device to resume.
*
* If PM operations are defined for the @dev's driver and they include
* ->runtime_resume(), execute it and return its error code. Otherwise,
* return -EINVAL.
*/
int pm_generic_runtime_resume(struct device *dev)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int ret;
ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : -EINVAL;
return ret;
}
EXPORT_SYMBOL_GPL(pm_generic_runtime_resume);
#endif /* CONFIG_PM_RUNTIME */
#ifdef CONFIG_PM_SLEEP
/**
* __pm_generic_call - Generic suspend/freeze/poweroff/thaw subsystem callback.
* @dev: Device to handle.
* @event: PM transition of the system under way.
*
* If the device has not been suspended at run time, execute the
* suspend/freeze/poweroff/thaw callback provided by its driver, if defined, and
* return its error code. Otherwise, return zero.
*/
static int __pm_generic_call(struct device *dev, int event)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int (*callback)(struct device *);
if (!pm || pm_runtime_suspended(dev))
return 0;
switch (event) {
case PM_EVENT_SUSPEND:
callback = pm->suspend;
break;
case PM_EVENT_FREEZE:
callback = pm->freeze;
break;
case PM_EVENT_HIBERNATE:
callback = pm->poweroff;
break;
case PM_EVENT_THAW:
callback = pm->thaw;
break;
default:
callback = NULL;
break;
}
return callback ? callback(dev) : 0;
}
/**
* pm_generic_suspend - Generic suspend callback for subsystems.
* @dev: Device to suspend.
*/
int pm_generic_suspend(struct device *dev)
{
return __pm_generic_call(dev, PM_EVENT_SUSPEND);
}
EXPORT_SYMBOL_GPL(pm_generic_suspend);
/**
* 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);
}
EXPORT_SYMBOL_GPL(pm_generic_freeze);
/**
* 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);
}
EXPORT_SYMBOL_GPL(pm_generic_poweroff);
/**
* 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);
}
EXPORT_SYMBOL_GPL(pm_generic_thaw);
/**
* __pm_generic_resume - Generic resume/restore callback for subsystems.
* @dev: Device to handle.
* @event: PM transition of the system under way.
*
* Execute the resume/resotre callback provided by the @dev's driver, if
* defined. If it returns 0, change the device's runtime PM status to 'active'.
* Return the callback's error code.
*/
static int __pm_generic_resume(struct device *dev, int event)
{
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
int (*callback)(struct device *);
int ret;
if (!pm)
return 0;
switch (event) {
case PM_EVENT_RESUME:
callback = pm->resume;
break;
case PM_EVENT_RESTORE:
callback = pm->restore;
break;
default:
callback = NULL;
break;
}
if (!callback)
return 0;
ret = callback(dev);
if (!ret) {
pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
}
return ret;
}
/**
* pm_generic_resume - Generic resume callback for subsystems.
* @dev: Device to resume.
*/
int pm_generic_resume(struct device *dev)
{
return __pm_generic_resume(dev, PM_EVENT_RESUME);
}
EXPORT_SYMBOL_GPL(pm_generic_resume);
/**
* pm_generic_restore - Generic restore callback for subsystems.
* @dev: Device to restore.
*/
int pm_generic_restore(struct device *dev)
{
return __pm_generic_resume(dev, PM_EVENT_RESTORE);
}
EXPORT_SYMBOL_GPL(pm_generic_restore);
#endif /* CONFIG_PM_SLEEP */
struct dev_pm_ops generic_subsys_pm_ops = {
#ifdef CONFIG_PM_SLEEP
.suspend = pm_generic_suspend,
.resume = pm_generic_resume,
.freeze = pm_generic_freeze,
.thaw = pm_generic_thaw,
.poweroff = pm_generic_poweroff,
.restore = pm_generic_restore,
#endif
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = pm_generic_runtime_suspend,
.runtime_resume = pm_generic_runtime_resume,
.runtime_idle = pm_generic_runtime_idle,
#endif
};
EXPORT_SYMBOL_GPL(generic_subsys_pm_ops);
......@@ -215,20 +215,59 @@ struct dev_pm_ops {
int (*runtime_idle)(struct device *dev);
};
#ifdef CONFIG_PM_SLEEP
#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
.suspend = suspend_fn, \
.resume = resume_fn, \
.freeze = suspend_fn, \
.thaw = resume_fn, \
.poweroff = suspend_fn, \
.restore = resume_fn,
#else
#define SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn)
#endif
#ifdef CONFIG_PM_RUNTIME
#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
.runtime_suspend = suspend_fn, \
.runtime_resume = resume_fn, \
.runtime_idle = idle_fn,
#else
#define SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn)
#endif
/*
* Use this if you want to use the same suspend and resume callbacks for suspend
* to RAM and hibernation.
*/
#define SIMPLE_DEV_PM_OPS(name, suspend_fn, resume_fn) \
const struct dev_pm_ops name = { \
.suspend = suspend_fn, \
.resume = resume_fn, \
.freeze = suspend_fn, \
.thaw = resume_fn, \
.poweroff = suspend_fn, \
.restore = resume_fn, \
SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
}
/*
* Use this for defining a set of PM operations to be used in all situations
* (sustem suspend, hibernation or runtime PM).
*/
#define UNIVERSAL_DEV_PM_OPS(name, suspend_fn, resume_fn, idle_fn) \
const struct dev_pm_ops name = { \
SET_SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
SET_RUNTIME_PM_OPS(suspend_fn, resume_fn, idle_fn) \
}
/*
* Use this for subsystems (bus types, device types, device classes) that don't
* need any special suspend/resume handling in addition to invoking the PM
* callbacks provided by device drivers supporting both the system sleep PM and
* runtime PM, make the pm member point to generic_subsys_pm_ops.
*/
#ifdef CONFIG_PM_OPS
extern struct dev_pm_ops generic_subsys_pm_ops;
#define GENERIC_SUBSYS_PM_OPS (&generic_subsys_pm_ops)
#else
#define GENERIC_SUBSYS_PM_OPS NULL
#endif
/**
* PM_EVENT_ messages
*
......
......@@ -62,6 +62,11 @@ static inline void device_set_run_wake(struct device *dev, bool enable)
dev->power.run_wake = enable;
}
static inline bool pm_runtime_suspended(struct device *dev)
{
return dev->power.runtime_status == RPM_SUSPENDED;
}
#else /* !CONFIG_PM_RUNTIME */
static inline int pm_runtime_idle(struct device *dev) { return -ENOSYS; }
......@@ -89,6 +94,7 @@ static inline void pm_runtime_get_noresume(struct device *dev) {}
static inline void pm_runtime_put_noidle(struct device *dev) {}
static inline bool device_run_wake(struct device *dev) { return false; }
static inline void device_set_run_wake(struct device *dev, bool enable) {}
static inline bool pm_runtime_suspended(struct device *dev) { return false; }
#endif /* !CONFIG_PM_RUNTIME */
......
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