On Thu, 4 Mar 2010, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@xxxxxxx> > Subject: PM: Provide generic subsystem-level callbacks > > There are subsystems whose power management callbacks only need to > invoke the callbacks provided by device drivers. Still, their system > sleep PM callbacks should play well with the runtime PM callbacks, > so that devices suspended at run time can be left in that state for > a system sleep transition. > > Provide a set of generic PM callbacks for such subsystems and > define convenience macros for populating dev_pm_ops structures. This looks pretty good, just a few minor typos and things that could be worded better. > +/** > + * pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems. > + * @dev: Device to suspend. > + * > + * If PM operations are defined for the driver of @dev and they include for @dev's driver > + * ->runtime_suspend(), execute it and return the error code returned by it. and return its error code. > + * Otherwise, return zero. Otherwise, return -EINVAL. > +/** > + * pm_generic_runtime_resume - Generic runtime resume callback for subsystems. > + * @dev: Device to resume. > + * > + * If PM operations are defined for the driver of @dev and they include > + * ->runtime_resume(), execute it and return the error code returned by it. > + * Otherwise, return zero. Same as above. > +/** > + * __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 the error code returned by it. Otherwise, return zero. return its error code. > +/** > + * __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 driver of @dev, if restore, @dev's driver > + * defined. If it returns 0, change the device's runtime PM status to 'active'. > + * Return the error code returned by it. Return the callback's error code. > --- linux-2.6.orig/Documentation/power/runtime_pm.txt > +++ linux-2.6/Documentation/power/runtime_pm.txt > @@ -335,6 +335,10 @@ drivers/base/power/runtime.c and include > 'power.runtime_error' is set or 'power.disable_depth' is greater than > zero) > > + bool pm_runtime_suspended(struct device *dev); > + - return true if the devices runtime PM status is 'suspended' or false > + otherwise device's run-time, comma before "or" > +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 execute pm_runtime_suspend() for it and call pm_runtime_suspend() for this device if the return value is 0 or the callback isn't 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 the result returned by it, or return its result (same change for the other functions below) > +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 passing NULL > +as the last argument of it. (possibly setting its last argument to NULL). Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
