After commit d856f39ac1cc ("PM / wakeup: Rework wakeup source timer
cancellation") wakeup_source_drop() is a trivial wrapper around
__pm_relax() and it has no users except for wakeup_source_destroy()
and wakeup_source_trash() which also has no users, so drop it along
with the latter and make wakeup_source_destroy() call __pm_relax()
directly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

During system suspend, a driver may find that the wakeup setting is
enabled for its device and therefore configures it to deliver system
wakeup signals.

Additionally, sometimes the driver and its device, relies on some
further consumed resource, like an irqchip or a phy for example, to
stay powered on, as to be able to deliver system wakeup signals.

In general the driver deals with this, via raising an "enable count"
of the consumed resource or via a subsystem specific API, like
irq_set_irq_wake() or enable|disable_irq_wake() for an irqchip.
However, this may not be sufficient in cases when the resource's
device may be attached to a PM domain (genpd for example) or is
handled by a non-trivial middle layer (PCI for example).

To address cases like these, the existing ->dev.power.wakeup_path
status flag is there to help.  As a matter of fact, genpd already
monitors the flag during system suspend and acts accordingly.

However, so far it has not been clear, if anybody else but the PM
core is allowed to set the ->dev.power.wakeup_path status flag,
which is required to make this work.  For this reason, introduce
a new helper function, device_set_wakeup_path() for that.

Typically, a driver that manages a resource needed in the wakeup path
should call device_set_wakeup_path() from its ->suspend() or
->suspend_late() callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The system wakeup framework is not very consistent with respect to
the way it handles suspend-to-idle and generally wakeup events
occurring during transitions to system low-power states.

First off, system transitions in progress are aborted by the event
reporting helpers like pm_wakeup_event() only if the wakeup_count
sysfs attribute is in use (as documented), but there are cases in
which system-wide transitions should be aborted even if that is
not the case.  For example, a wakeup signal from a designated
wakeup device during system-wide PM transition, it should cause
the transition to be aborted right away.

Moreover, there is a freeze_wake() call in wakeup_source_activate(),
but that really is only effective after suspend_freeze_state has
been set to FREEZE_STATE_ENTER by freeze_enter().  However, it
is very unlikely that wakeup_source_activate() will ever be called
at that time, as it could only be triggered by a IRQF_NO_SUSPEND
interrupt handler, so wakeups from suspend-to-idle don't really
occur in wakeup_source_activate().

At the same time there is a way to abort a system suspend in
progress (or wake up the system from suspend-to-idle), which is by
calling pm_system_wakeup(), but in turn that doesn't cause any
wakeup source objects to be activated, so it will not be covered
by wakeup source statistics and will not prevent the system from
suspending again immediately (in case autosleep is used, for
example).  Consequently, if anyone wants to abort system transitions
in progress and allow the wakeup_count mechanism to work, they need
to use both pm_system_wakeup() and pm_wakeup_event(), say, at the
same time which is awkward.

For the above reasons, make it possible to trigger
pm_system_wakeup() from within wakeup_source_activate() and
provide a new pm_wakeup_hard_event() helper to do so within the
wakeup framework.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Turns out we can automate the handling for the device_may_wakeup()
quite a bit by using the kernel wakeup source list as suggested
by Rafael J. Wysocki <rjw@rjwysocki.net>.

And as some hardware has separate dedicated wake-up interrupt
in addition to the IO interrupt, we can automate the handling by
adding a generic threaded interrupt handler that just calls the
device PM runtime to wake up the device.

This allows dropping code from device drivers as we currently
are doing it in multiple ways, and often wrong.

For most drivers, we should be able to drop the following
boilerplate code from runtime_suspend and runtime_resume
functions:

	...
	device_init_wakeup(dev, true);
	...
	if (device_may_wakeup(dev))
		enable_irq_wake(irq);
	...
	if (device_may_wakeup(dev))
		disable_irq_wake(irq);
	...
	device_init_wakeup(dev, false);
	...

We can replace it with just the following init and exit
time code:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

And for hardware with dedicated wake-up interrupts:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_dedicated_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Fix a comment typo (sorce -> source) in pm_wakeup.h.

[rjw: Changelog]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Android uses one wakelock statistics that is only necessary for
opportunistic sleep.  Namely, the prevent_suspend_time field
accumulates the total time the given wakelock has been locked
while "automatic suspend" was enabled.  Add an analogous field,
prevent_sleep_time, to wakeup sources and make it behave in a similar
way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Wakeup statistics used by Android are slightly different from what we
have in wakeup sources at the moment and there aren't any known
users of those statistics other than Android, so modify them to make
it easier for Android to switch to wakeup sources.

This removes the struct wakeup_source's hit_cout field, which is very
rough and therefore not very useful, and adds two new fields,
wakeup_count and expire_count.  The first one tracks how many times
the wakeup source is activated with events_check_enabled set (which
roughly corresponds to the situations when a system power transition
to a sleep state is in progress and would be aborted by this wakeup
source if it were the only active one at that time) and the second
one is the number of times the wakeup source has been activated with
a timeout that expired.

Additionally, the last_time field is now updated when the wakeup
source is deactivated too (previously it was only updated during
the wakeup source's activation), which seems to be what Android does
with the analogous counter for wakelocks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The existing wakeup source initialization routines are not
particularly useful for wakeup sources that aren't created by
wakeup_source_create(), because their users have to open code
filling the objects with zeros and setting their names.  For this
reason, introduce routines that can be used for initializing, for
example, static wakeup source objects.

Requested-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Currently, wakeup sysfs attributes are created for all devices,
regardless of whether or not they are wakeup-capable.  This is
excessive and complicates wakeup device identification from user
space (i.e. to identify wakeup-capable devices user space has to read
/sys/devices/.../power/wakeup for all devices and see if they are not
empty).

Fix this issue by avoiding to create wakeup sysfs files for devices
that cannot wake up the system from sleep states (i.e. whose
power.can_wakeup flags are unset during registration) and modify
device_set_wakeup_capable() so that it adds (or removes) the relevant
sysfs attributes if a device's wakeup capability status is changed.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Commit 074037e (PM / Wakeup: Introduce wakeup source objects and
event statistics (v3)) caused ACPI wakeup to only work if
CONFIG_PM_SLEEP is set, but it also worked for CONFIG_PM_SLEEP unset
before.  This can be fixed by making device_set_wakeup_enable(),
device_init_wakeup() and device_may_wakeup() work in the same way
as before commit 074037e when CONFIG_PM_SLEEP is unset.

Reported-and-tested-by: Justin Maggard <jmaggard10@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>