linux-toradex.git/include/linux/pm.h, branch v2.6.35.3

PM: Provide generic subsystem-level callbacks

2010-03-06T20:28:37+00:00

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.

Signed-off-by: Rafael J. Wysocki

PM: Allow device drivers to use dpm_wait()

2010-02-26T19:39:11+00:00

There are some dependencies between devices (in particular, between
EHCI USB controllers and their OHCI/UHCI siblings) which are not
reflected by the structure of the device tree.  With synchronous
suspend and resume these dependencies are taken into accout
automatically, because the devices in question are always registered
in the right order, but to meet these constraints with asynchronous
suspend and resume the drivers of these devices will need to use
dpm_wait() in their suspend/resume routines, so introduce a helper
function allowing them to do that.

Signed-off-by: Rafael J. Wysocki

PM: Asynchronous suspend and resume of devices

2010-02-26T19:39:09+00:00

Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other.  However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself.  Analogously, we're not allowed to resume a device before
resuming its parent.

The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.

For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices).  For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.

The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
    for the device or, in the case of devices with the
    power.async_suspend flags unset, before executing the device's
    suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
    and device class suspend callbacks for the device, the PM core
    waits for the completions of all the device's children to be
    completed.
(4) During resume, right before running the bus type, device type and
    device class resume callbacks for the device, the PM core waits
    for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
    after the bus type, device type and device class suspend (or
    resume) callbacks executed for the device have returned.

Signed-off-by: Rafael J. Wysocki

PM / Runtime: Add sysfs switch for disabling device run-time PM

2010-02-26T19:39:08+00:00

Add new device sysfs attribute, power/control, allowing the user
space to block the run-time power management of the devices.  If this
attribute is set to "on", the driver of the device won't be able to power
manage it at run time (without breaking the rules) and the device will
always be in the full power state (except when the entire system goes
into a sleep state).

Signed-off-by: Rafael J. Wysocki 
Acked-by: Alan Stern

const: constify remaining dev_pm_ops

2009-12-15T16:53:25+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM: Add flag for devices capable of generating run-time wake-up events

2009-12-06T15:17:57+00:00

Apparently, there are devices that can wake up the system from sleep
states and yet are incapable of generating wake-up events at run
time.  Thus, introduce a flag indicating if given device is capable
of generating run-time wake-up events.

Signed-off-by: Rafael J. Wysocki

PM: Add convenience macro to make switching to dev_pm_ops less error-prone

2009-09-14T18:27:00+00:00

In a number of cases, the .suspend, .freeze, .poweroff and .resume,
.thaw, .restore functions are identical. However, they all need to be
assigned to avoid regressionsm as the previous code called .suspend
resp. .resume in all those cases. SIMPLE_DEV_PM_OPS helps to deal
with this case.

[rjw: Changed the name of the macro and added the comment explaining its
 purpose.]

Signed-off-by: Albin Tonnerre 
Signed-off-by: Rafael J. Wysocki

PM: Introduce core framework for run-time PM of I/O devices (rev. 17)

2009-08-22T22:04:44+00:00

Introduce a core framework for run-time power management of I/O
devices.  Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'.  Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level.  Document all these things.

Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Magnus Damm

PM core: rename suspend and resume functions

2009-06-12T19:32:31+00:00

This patch (as1241) renames a bunch of functions in the PM core.
Rather than go through a boring list of name changes, suffice it to
say that in the end we have a bunch of pairs of functions:

	device_resume_noirq	dpm_resume_noirq
	device_resume		dpm_resume
	device_complete		dpm_complete
	device_suspend_noirq	dpm_suspend_noirq
	device_suspend		dpm_suspend
	device_prepare		dpm_prepare

in which device_X does the X operation on a single device and dpm_X
invokes device_X for all devices in the dpm_list.

In addition, the old dpm_power_up and device_resume_noirq have been
combined into a single function (dpm_resume_noirq).

Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions
of the former top-level device_suspend and device_resume routines.

Signed-off-by: Alan Stern 
Acked-by: Magnus Damm 
Signed-off-by: Rafael J. Wysocki

PM: Rename device_power_down/up()

2009-06-12T19:32:31+00:00

Rename the functions performing "_noirq" dev_pm_ops
operations from device_power_down() and device_power_up()
to device_suspend_noirq() and device_resume_noirq().

The new function names are chosen to show that the functions
are responsible for calling the _noirq() versions to finalize
the suspend/resume operation. The current function names do
not perform power down/up anymore so the names may be misleading.

Global function renames:
- device_power_down() -> device_suspend_noirq()
- device_power_up() -> device_resume_noirq()

Static function renames:
- suspend_device_noirq() -> __device_suspend_noirq()
- resume_device_noirq() -> __device_resume_noirq()

Signed-off-by: Magnus Damm 
Acked-by: Greg Kroah-Hartman 
Acked-by: Len Brown 
Signed-off-by: Rafael J. Wysocki