PM: sleep: Add helpers to allow a device to remain powered-on

On some platforms a device and its corresponding PM domain, may need to
remain powered-on during system wide suspend, to support various use cases.
For example, when the console_suspend_enabled flag is unset for a serial
controller, the corresponding device may need to remain powered on. Other
use cases exists too.

In fact, we already have the mechanism in the PM core to deal with these
kind of use cases. However, the current naming of the corresponding
functions/flags clearly suggests these should be use for system wakeup.
See device_wakeup_path(), device_set_wakeup_path and
dev->power.wakeup_path.

As a way to extend the use of the existing mechanism, let's introduce two
new helpers functions, device_awake_path() and device_set_awake_path(). At
this point, let them act as wrappers of the existing functions. Ideally,
when all users have been converted to use the new helpers, we may decide to
drop the old ones and rename the flag.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP

Previously the CONFIG_PM_SLEEP and !CONFIG_PM_SLEEP device_init_wakeup()
implementations differed in confusing ways:

- The PM_SLEEP version checked for a NULL device pointer and returned
-EINVAL, while the !PM_SLEEP version did not and would simply
dereference a NULL pointer.

- When called with "false", the !PM_SLEEP version cleared "capable" and
"enable" in the opposite order of the PM_SLEEP version. That was
harmless because for !PM_SLEEP they're simple assignments, but it's
unnecessary confusion.

Use a simplified version of the PM_SLEEP implementation for both cases.

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

PM: sleep: Add dev_wakeup_path() helper

Add dev_wakeup_path() helper to avoid to spread
dev->power.wakeup_path test in drivers.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: wakeup: Add routine to help fetch wakeup source object.

Some user might want to go through all registered wakeup sources
and doing things accordingly. For example, SoC PM driver might need to
do HW programming to prevent powering down specific IP which wakeup
source depending on. So add this API to help walk through all registered
wakeup source objects on that list and return them one by one.

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

PM / wakeup: Show wakeup sources stats in sysfs

Add an ID and a device pointer to 'struct wakeup_source'. Use them to to
expose wakeup sources statistics in sysfs under
/sys/class/wakeup/wakeup<ID>/*.

Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Tri Vo <trong@android.com>
Tested-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeup: Drop wakeup_source_init(), wakeup_source_prepare()

wakeup_source_init() has no users. Remove it.

As a result, wakeup_source_prepare() is only called from
wakeup_source_create(). Merge wakeup_source_prepare() into
wakeup_source_create() and remove it.

Change wakeup_source_create() behavior so that assigning NULL to wakeup
source's name throws an error.

Signed-off-by: Tri Vo <trong@android.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: Update struct wakeup_source documentation

The kerneldoc comment for struct wakeup_source has become outdated,
so fix that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / wakeup: Drop wakeup_source_drop()

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>

PM / wakeup: Add device_set_wakeup_path() helper to control wakeup path

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>

PM / wakeup: Integrate mechanism to abort transitions in progress

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>

PM / Wakeirq: Add automated device wake IRQ handling

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>

PM / Sleep: Fix comment typo in pm_wakeup.h

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>

PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources

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>

PM / Sleep: Change wakeup source statistics to follow Android

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>

PM / Sleep: Add more wakeup source initialization routines

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>

PM: Do not create wakeup sysfs files for devices that cannot wake up

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>

PM: Make ACPI wakeup from S5 work again when CONFIG_PM_SLEEP is unset

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>

PM / Wakeup: Introduce wakeup source objects and event statistics (v3)

Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.

Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.

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

PM: describe kernel policy regarding wakeup defaults (v. 2)

This patch (as1381b) updates a comment describing the kernel's policy
toward enabling wakeup by default.

It also makes device_set_wakeup_capable() actually do something when
CONFIG_PM isn't enabled. It's not clear this is necessary; however if
it isn't then device_init_wakeup() and device_can_wakeup() should also
be do-nothing routines. Furthermore, I don't expect this change to
have any noticeable effect -- but if it does then clearly the old
behavior was wrong.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: pm_wakeup - switch to using bool

Also change couple of stubs implemented as macros in !CONFIG_PM case
in statinc inline functions to provide proper typechecking of
arguments regardless of config.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI: include linux/pm_wakeup.h for device_set_wakeup_capable

drivers/pci/pci.c needs pm_wakeup.h since it uses device_set_wakup_capable().
The latter also needs to be stubbed out for !CONFIG_PM.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI ACPI: Rework PCI handling of wake-up

* Introduce function acpi_pm_device_sleep_wake() for enabling and
disabling the system wake-up capability of devices that are power
manageable by ACPI.

* Introduce function acpi_bus_can_wakeup() allowing other (dependent)
subsystems to check if ACPI is able to enable the system wake-up
capability of given device.

* Introduce callback .sleep_wake() in struct pci_platform_pm_ops and
for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake().

* Introduce callback .can_wakeup() in struct pci_platform_pm_ops and
for the ACPI 'driver' make it use acpi_bus_can_wakeup().

* Move the PME# handlig code out of pci_enable_wake() and split it
into two functions, pci_pme_capable() and pci_pme_active(),
allowing the caller to check if given device is capable of
generating PME# from given power state and to enable/disable the
device's PME# functionality, respectively.

* Modify pci_enable_wake() to use the new ACPI callbacks and the new
PME#-related functions.

* Drop the generic .platform_enable_wakeup() callback that is not
used any more.

* Introduce device_set_wakeup_capable() that will set the
power.can_wakeup flag of given device.

* Rework PCI device PM initialization so that, if given device is
capable of generating wake-up events, either natively through the
PME# mechanism, or with the help of the platform, its
power.can_wakeup flag is set and its power.should_wakeup flag is
unset as appropriate.

* Make ACPI set the power.can_wakeup flag for devices found to be
wake-up capable by it.

* Make the ACPI wake-up code enable/disable GPEs for devices that
have the wakeup.flags.prepared flag set (which means that their
wake-up power has been enabled).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PM: Convert wakeup flag accessors to inline functions

This patch (as1058) improves the wakeup macros in include/linux/pm.h.
All but the trivial ones are converted to inline routines, which
requires moving them to a separate header file since they depend on
the definition of struct device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>