When a device is probed, the function dev_pm_domain_attach() is called
to see if there is a power-domain that is associated with the device and
needs to be turned on. If dev_pm_domain_attach() does not return
-EPROBE_DEFER then the device will be probed.

For devices using genpd, dev_pm_domain_attach() will call
genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power
domain associated with the device then it returns an error code not
equal to -EPROBE_DEFER to allow the device to be probed. However, if
genpd_dev_pm_attach() does find a power-domain that is associated with
the device, then it does not return -EPROBE_DEFER on failure and hence
the device will still be probed. Furthermore, genpd_dev_pm_attach() does
not check the error code returned by pm_genpd_poweron() to see if the
power-domain was turned on successfully.

Fix this by checking the return code from pm_genpd_poweron() and
returning -EPROBE_DEFER from genpd_dev_pm_attach on failure, if there
is a power-domain associated with the device.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Genpd's ->runtime_suspend() (assigned to pm_genpd_runtime_suspend())
doesn't immediately walk the hierarchy of ->runtime_suspend() callbacks.
Instead, pm_genpd_runtime_suspend() calls pm_genpd_poweroff() which
postpones that until *all* the devices in the genpd are runtime suspended.

When pm_genpd_poweroff() discovers that the last device in the genpd is
about to be runtime suspended, it calls __pm_genpd_save_device() for *all*
the devices in the genpd sequentially. Furthermore,
__pm_genpd_save_device() invokes the ->start() callback, walks the
hierarchy of the ->runtime_suspend() callbacks and invokes the ->stop()
callback. This causes a "thundering herd" problem.

Let's address this issue by having pm_genpd_runtime_suspend() immediately
walk the hierarchy of the ->runtime_suspend() callbacks, instead of
postponing that to the power off sequence via pm_genpd_poweroff(). If the
selected ->runtime_suspend() callback doesn't return an error code, call
pm_genpd_poweroff() to see if it's feasible to also power off the PM
domain.

Adopting this change enables us to simplify parts of the code in genpd,
for example the locking mechanism. Additionally, it gives some positive
side effects, as described below.

i)
One device's ->runtime_resume() latency is no longer affected by other
devices' latencies in a genpd.

The complexity genpd has to support the option to abort the power off
sequence suffers from latency issues. More precisely, a device that is
requested to be runtime resumed, may end up waiting for
__pm_genpd_save_device() to complete its operations for *another* device.
That's because pm_genpd_poweroff() can't confirm an abort request while it
waits for __pm_genpd_save_device() to return.

As this patch removes the intermediate states in pm_genpd_poweroff() while
powering off the PM domain, we no longer need the ability to abort that
sequence.

ii)
Make pm_runtime[_status]_suspended() reliable when used with genpd.

Until the last device in a genpd becomes idle, pm_genpd_runtime_suspend()
will return 0 without actually walking the hierarchy of the
->runtime_suspend() callbacks. However, by returning 0 the runtime PM core
considers the device as runtime_suspended, so
pm_runtime[_status]_suspended() will return true, even though the device
isn't (yet) runtime suspended.

After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks,
pm_runtime[_status]_suspended() will accurately reflect the status of the
device.

iii)
Enable fine-grained PM through runtime PM callbacks in drivers/subsystems.

There are currently cases were drivers/subsystems implements runtime PM
callbacks to deploy fine-grained PM (e.g. gate clocks, move pinctrl to
power-save state, etc.). While using the genpd, pm_genpd_runtime_suspend()
postpones invoking these callbacks until *all* the devices in the genpd
are runtime suspended. In essence, one runtime resumed device prevents
fine-grained PM for other devices within the same genpd.

After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks, fine-grained PM is enabled
throughout all the levels of runtime PM callbacks.

iiii)
Enable fine-grained PM for IRQ safe devices

Per the definition for an IRQ safe device, its runtime PM callbacks must
be able to execute in atomic context. In the path while genpd walks the
hierarchy of the ->runtime_suspend() callbacks for the device, it uses a
mutex. Therefore, genpd prevents that path to be executed for IRQ safe
devices.

As this patch changes pm_genpd_runtime_suspend() to immediately walk the
hierarchy of the ->runtime_suspend() callbacks and without needing to use
a mutex, fine-grained PM is enabled throughout all the levels of runtime
PM callbacks for IRQ safe devices.

Unfortunately this patch also comes with a drawback, as described in the
summary below.

Driver's/subsystem's runtime PM callbacks may be invoked even when the
genpd hasn't actually powered off the PM domain, potentially introducing
unnecessary latency.

However, in most cases, saving/restoring register contexts for devices are
typically fast operations or can be optimized in device specific ways
(e.g. shadow copies of register contents in memory, device-specific checks
to see if context has been lost before restoring context, etc.).

Still, in some cases the driver/subsystem may suffer from latency if
runtime PM is used in a very fine-grained manner (e.g. for each IO request
or xfer). To prevent that extra overhead, the driver/subsystem may deploy
the runtime PM autosuspend feature.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NLina Iyer <lina.iyer@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If pm_genpd_{add,remove}_device() keeps on failing with -EAGAIN, we end
up with an infinite loop in genpd_dev_pm_{at,de}tach().

This may happen due to a genpd.prepared_count imbalance.  This is a bug
elsewhere, but it will result in a system lock up, possibly during
reboot of an otherwise functioning system.

To avoid this, put a limit on the maximum number of loop iterations,
using an exponential back-off mechanism.  If the limit is reached, the
operation will just fail.  An error message is already printed.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The PM Domain code uses ktime_get() to perform various latency
measurements.  However, if ktime_get() is called while timekeeping is
suspended, the following warning is printed:

    WARNING: CPU: 0 PID: 1340 at kernel/time/timekeeping.c:576 ktime_get+0x3

This happens when resuming the PM Domain that contains the clock events
source, which calls pm_genpd_syscore_poweron(). Chain of operations is:

    timekeeping_resume()
    {
	clockevents_resume()
	    sh_cmt_clock_event_resume()
		pm_genpd_syscore_poweron()
		    pm_genpd_sync_poweron()
			genpd_syscore_switch()
			    genpd_power_on()
				ktime_get(), but timekeeping_suspended == 1
	...
	timekeeping_suspended = 0;
    }

Fix this by adding a "timed" parameter to genpd_power_{on,off}() and
pm_genpd_sync_power{off,on}(), to indicate whether latency measurements
are allowed.  This parameter is passed as false in
genpd_syscore_switch() (i.e. during syscore suspend/resume), and true in
all other cases.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

pm_genpd_remove_device() tries hard to validate the generic PM domain
passed to it, but the validation is not complete.

dev->pm_domain contains a struct dev_pm_domain, which is the "base
class" of generic PM domains.  Other users of dev_pm_domains include
stuff like vga_switheroo.  Hence, a device could have a generic PM
domain or a vga_switcheroo PM domain in dev->pm_domain.

We need ot be certain that the PM domain is actually valid before we
try to remove it.  We can do this easily as we have a way to get the
current validated generic PM domain for a struct device.  This must
match the generic PM domain being requested for removal.

Convert the code to use this alternative validation method instead.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The PM domain code contains two methods to get the generic PM domain
for a struct device.  One is dev_to_genpd() which is only safe when
we know for certain that the device has a generic PM domain attached.
The other is coded into genpd_dev_pm_detach() which ensures that the
PM domain in the struct device is a generic PM domain (and so is safer).

This commit factors out the safer version, documents it, and hides the
unsafe dev_to_genpd().
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PM domains are rather noisy; scheduling behaviour can cause callbacks
to take longer, which causes them to spit out a warning-level message
each time a callback takes a little longer than the previous time.
There really isn't a need for this, except when debugging.
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Buses which currently supports attaching devices to their PM domains,
will invoke the dev_pm_domain_attach() API from their ->probe()
callbacks. During the attach procedure, genpd power up the PM domain.

In those scenarios where the bus/driver don't need to access its device
during probe, it may leave it in runtime PM suspended state since
that's also the default state. In that way, no notifications through
the runtime PM callbacks will reach the PM domain during probe.

For genpd, the consequence from the above scenario means the PM domain
will remain powered. Therefore, implement the struct dev_pm_domain's
->sync() callback, which is invoked from driver core after the
bus/driver has probed the device. It allows genpd to power off the PM
domain if it's unused.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
[ Ulf: Updated patch according to updates in driver core ]
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To keep consisitency with the rest of the file, use 'genpd' as the
name of the 'struct generic_pm_domain' pointer instead of 'gpd'.

This is just a rename, no functional changes.
Signed-off-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The optional genpd's ->attach_dev() callback is invoked from
__pm_genpd_add_device(). Let's add error handling from the response
from this callback and propagate the error code.

When __pm_genpd_add_device() is invoked through the generic OF-based PM
domain look-up path, the device is being probed. Returning an error
will mean the device won't be attached to its PM domain. Errors of
-EPROBE_DEFER get special treatment and is propagated to the driver
core.

Therefore this change also enables the ->attach_dev() callback to
be able to request for a deferred probe sequence.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move the initialization of the struct generic_pm_domain_data into
genpd_alloc_dev_data(), including the assignment of the device's
->pm_domain() callback. Make corresponding changes to
genpd_free_dev_data().

These changes will make the related code more readable. It will also
decrease the critical regions for where genpd's mutex is being held and
for where the device's power related spinlock is being held.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The error path in __pm_genpd_add_device() didn't decrease the reference
to the struct pm_subsys_data.

Let's move the calls to dev_pm_get|put_subsys_data() into
genpd_alloc|free_dev_data() to fix this issue and thus prevent a
potential memory leakage.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

While adding devices to their PM domains, dev_pm_qos_add_notifier() was
invoked while allocating the generic_pm_domain_data for the device.

Since the generic_pm_domain_data's device pointer will be assigned
after allocation, the ->genpd_dev_pm_qos_notifier() callback could be
called prior having a valid pointer to the device. Similar scenario
existed while removing a device from a genpd.

To cope with these scenarios a mutex was used to protect the pointer to
the device.

By re-order the sequence for when dev_pm_qos_add|remove_notifier() are
invoked, we make sure the ->genpd_dev_pm_qos_notifier() callback are
always called with a valid device pointer available.

In this way, we eliminate the need for protecting the pointer and thus
we can remove the mutex from the struct generic_pm_domain_data.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When adding a device to a genpd, we no longer need to walk genpd's list
of existing devices to verify it hasn't already been added.

Instead we can now rely on the verification of not allowing existing
generic_pm_domain_data for a device, since that has the same meaning.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When adding a device to a genpd, a struct generic_pm_domain_data is
allocated per device.

Verify that there are no existing generic_pm_domain_data for the device
we are about to add, since that tells us it has already been added to a
genpd.

When genpd supported PM domain device callbacks, this was a valid
scenario. Now it isn't so let's return an error code.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The reference counting was needed when genpd supported PM domain device
callbacks. Since this option has been removed, let's also remove the
reference counting of the struct generic_pm_domain_data.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In a step to get consistent names of functions in genpd, rename
the internal __pm_genpd_alloc|free_dev_data() into
gendp_alloc|free_dev_data().

As discussed on the linux-pm list, let's move towards the following
name rules:

Internal functions:
genpd_*
_genpd_*
__genpd_*

External functions:
pm_genpd_*
_pm_genpd_*
__pm_genpd_*
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are currently no users of this API, let's remove it.

Additionally, if such feature would be needed future wise, a better
option is likely use pm_runtime_set_active|suspended() in some form.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This function looks up a PM domain form the provider. This will be
useful to add parent/child domain relationship from the SoC specific
code. The caller of the function must make sure that PM domain provider
is already registered.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NAmit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After commit b2b49ccb (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM or even may be dropped entirely in some cases.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code.
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It's quite common for PM domains to use PM clocks. Typically from SOC
specific code, the per device PM clock list is created and
pm_clk_suspend|resume() are invoked to handle clock gating/ungating.

A step towards consolidation is to integrate PM clock support into
genpd, which is what this patch does.

In this initial step, the calls to the pm_clk_suspend|resume() are
handled within genpd, but the per device PM clock list still needs to
be created from SOC specific code. It seems reasonable to have gendp to
handle that as well, but that left to future patches to address.

It's not every users of genpd that are keen on using PM clocks, thus we
need to provide this a configuration option for genpd. Therefore let's
add flag field in the genpd struct to keep this information and define
a new GENDP_FLAG_PM_CLK bit for it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Vast amount of platform drivers which enables runtime PM, don't invoke
a pm_runtime_get_sync() while probing their devices.

Instead, once they have turned on their PM resourses during ->probe()
and are ready to handle I/O, these invokes pm_runtime_set_active() to
synchronize its state towards the runtime PM core.

From the runtime PM point of view this behavior is perfectly acceptable,
but we encounter probe failures if their corresponding devices resides
in the generic PM domain. The issues are observed for those devices,
which requires its PM domain to stay powered during ->probe() since
that's not being controlled.

While using the generic OF-based PM domain look-up, a device's PM
domain will be attached during the probe sequence. For this path, let's
fix the probe failures, by simply power on the PM domain right after
when it's been attached to the device.

The generic PM domain stays powered until all of its devices becomes
runtime PM enabled and runtime PM suspended.

The old SOCs which makes use of the generic PM domain but don't use the
generic OF-based PM domain look-up, will not be affected from this
change.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

PM domains are powered on/off from various places. Some callers do
latency measurements, others don't. Consolidate using two helper
functions, which always measure the latencies, and update the stored
latencies when needed.

Other minor changes:
  - Use pr_warn() instead of pr_warning(),
  - There's no need to check genpd->name, %s handles NULL pointers fine,
  - Make the warning format strings identical, to save memory.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The PM domain pointed to by the genpd parameter is never modified.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NKevin Hilman <khilman@linaro.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The initial state of the device's need_restore flag should'nt depend on
the current state of the PM domain. For example it should be perfectly
valid to attach an inactive device to a powered PM domain.

The pm_genpd_dev_need_restore() API allow us to update the need_restore
flag to somewhat cope with such scenarios. Typically that should have
been done from drivers/buses ->probe() since it's those that put the
requirements on the value of the need_restore flag.

Until recently, the Exynos SOCs were the only user of the
pm_genpd_dev_need_restore() API, though invoking it from a centralized
location while adding devices to their PM domains.

Due to that Exynos now have swithed to the generic OF-based PM domain
look-up, it's no longer possible to invoke the API from a centralized
location. The reason is because devices are now added to their PM
domains during the probe sequence.

Commit "ARM: exynos: Move to generic PM domain DT bindings"
did the switch for Exynos to the generic OF-based PM domain look-up,
but it also removed the call to pm_genpd_dev_need_restore(). This
caused a regression for some of the Exynos drivers.

To handle things more properly in the generic PM domain, let's change
the default initial value of the need_restore flag to reflect that the
state is unknown. As soon as some of the runtime PM callbacks gets
invoked, update the initial value accordingly.

Moreover, since the generic PM domain is verifying that all devices
are both runtime PM enabled and suspended, using pm_runtime_suspended()
while pm_genpd_poweroff() is invoked from the scheduled work, we can be
sure of that the PM domain won't be powering off while having active
devices.

Do note that, the generic PM domain can still only know about active
devices which has been activated through invoking its runtime PM resume
callback. In other words, buses/drivers using pm_runtime_set_active()
during ->probe() will still suffer from a race condition, potentially
probing a device without having its PM domain being powered. That issue
will have to be solved using a different approach.

This a log from the boot regression for Exynos5, which is being fixed in
this patch.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 308 at ../drivers/clk/clk.c:851 clk_disable+0x24/0x30()
Modules linked in:
CPU: 0 PID: 308 Comm: kworker/0:1 Not tainted 3.18.0-rc3-00569-gbd9449f-dirty #10
Workqueue: pm pm_runtime_work
[<c0013c64>] (unwind_backtrace) from [<c0010dec>] (show_stack+0x10/0x14)
[<c0010dec>] (show_stack) from [<c03ee4cc>] (dump_stack+0x70/0xbc)
[<c03ee4cc>] (dump_stack) from [<c0020d34>] (warn_slowpath_common+0x64/0x88)
[<c0020d34>] (warn_slowpath_common) from [<c0020d74>] (warn_slowpath_null+0x1c/0x24)
[<c0020d74>] (warn_slowpath_null) from [<c03107b0>] (clk_disable+0x24/0x30)
[<c03107b0>] (clk_disable) from [<c02cc834>] (gsc_runtime_suspend+0x128/0x160)
[<c02cc834>] (gsc_runtime_suspend) from [<c0249024>] (pm_generic_runtime_suspend+0x2c/0x38)
[<c0249024>] (pm_generic_runtime_suspend) from [<c024f44c>] (pm_genpd_default_save_state+0x2c/0x8c)
[<c024f44c>] (pm_genpd_default_save_state) from [<c024ff2c>] (pm_genpd_poweroff+0x224/0x3ec)
[<c024ff2c>] (pm_genpd_poweroff) from [<c02501b4>] (pm_genpd_runtime_suspend+0x9c/0xcc)
[<c02501b4>] (pm_genpd_runtime_suspend) from [<c024a4f8>] (__rpm_callback+0x2c/0x60)
[<c024a4f8>] (__rpm_callback) from [<c024a54c>] (rpm_callback+0x20/0x74)
[<c024a54c>] (rpm_callback) from [<c024a930>] (rpm_suspend+0xd4/0x43c)
[<c024a930>] (rpm_suspend) from [<c024bbcc>] (pm_runtime_work+0x80/0x90)
[<c024bbcc>] (pm_runtime_work) from [<c0032a9c>] (process_one_work+0x12c/0x314)
[<c0032a9c>] (process_one_work) from [<c0032cf4>] (worker_thread+0x3c/0x4b0)
[<c0032cf4>] (worker_thread) from [<c003747c>] (kthread+0xcc/0xe8)
[<c003747c>] (kthread) from [<c000e738>] (ret_from_fork+0x14/0x3c)
---[ end trace 40cd58bcd6988f12 ]---

Fixes: a4a8c2c4 (ARM: exynos: Move to generic PM domain DT bindings)
Reported-and-tested0by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Convert the prototypes to return an int in order to support error
handling in these callbacks.

Also, as suggested by Dmitry Torokhov, pass the domain pointer for use
inside the callbacks, and so that they match the existing
power_on/power_off callbacks which currently take the domain pointer.
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
[ khilman: added domain as parameter to callbacks, as suggested by Dmitry ]
Signed-off-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The "cpu_data" are defined for some archs and thus conflicting with the
"cpu_data" member in the struct gpd_cpu_data. This causes a compiler
error for those archs.

Let's fix it by rename the member to cpuidle_data. In this context it
also seems appropriate to rename the struct to gpd_cpuidle_data to
better reflect its use.

Fixes: f48c767c (PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h)
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are no active clients of the legacy API and we now also have a
better way to handle genpd DT support. So let's remove the legacy API.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

While a PM domain can enable PM runtime management of its devices' module
clocks by setting

	genpd->dev_ops.stop = pm_clk_suspend;
	genpd->dev_ops.start = pm_clk_resume;

this also requires registering the clocks with the pm_clk subsystem.
In the legacy case, this is handled by the platform code, after
attaching the device to its PM domain.

When the devices are instantiated from DT, devices are attached to their
PM domains by generic code, leaving no method for the platform-specific
PM domain code to register their clocks.

Add two callbacks, allowing a PM domain to perform platform-specific
tasks when a device is attached to or detached from a PM domain.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add /sys/kernel/debug/pm_genpd/pm_genpd_summary file, which
lists power domains in the system, their statuses and attached devices,
resembling /sys/kernel/debug/clk/clk_summary.

Currently it is impossible to inspect (from userland) whether
a power domain is on or off. And, if it is on, which device blocks it
from powering down. This change allows developers working on
embedded devices power efficiency to list all necessary information
about generic power domains in one place.

The content of pm_genpd/pm_genpd_summary file is generated by iterating
over all generic power domain in the system, and, for each,
over registered devices and over the subdomains, if present.

Example output:
$ cat  /sys/kernel/debug/pm_genpd/pm_genpd_summary
    domain                      status         slaves
           /device                                      runtime status
----------------------------------------------------------------------
a4su                            off
a3sg                            off
a3sm                            on
a3sp                            on
    /devices/e6600000.pwm                               suspended
    /devices/e6c50000.serial                            active
    /devices/e6850000.sd                                suspended
    /devices/e6bd0000.mmc                               active
a4s                             on               a3sp, a3sm, a3sg
    /devices/e6900000.irqpin                            unsupported
    /devices/e6900004.irqpin                            unsupported
    /devices/e6900008.irqpin                            unsupported
    /devices/e690000c.irqpin                            unsupported
    /devices/e9a00000.ethernet                          active
a3rv                            off
a4r                             off              a3rv
    /devices/fff20000.i2c                               suspended
a4lc                            off
c5                              on               a4lc, a4r, a4s, a4su
    /devices/e6050000.pfc                               unsupported
    /devices/e6138000.timer                             active

To enable this feature, compile the kernel with debugfs
and CONFIG_PM_ADVANCED_DEBUG enabled.
Signed-off-by: NMaciej Matraszek <m.matraszek@samsung.com>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This patch introduces generic code to perform PM domain look-up using
device tree and automatically bind devices to their PM domains.

Generic device tree bindings are introduced to specify PM domains of
devices in their device tree nodes.

Backwards compatibility with legacy Samsung-specific PM domain bindings
is provided, but for now the new code is not compiled when
CONFIG_ARCH_EXYNOS is selected to avoid collision with legacy code.
This will change as soon as the Exynos PM domain code gets converted to
use the generic framework in further patch.

This patch was originally submitted by Tomasz Figa when he was employed
by Samsung.

Link: http://marc.info/?l=linux-pm&m=139955349702152&w=2Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NRob Herring <robh@kernel.org>
Tested-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

As default behavior let genpd at late init try to disable the unused
PM domains.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are no active users of this API. Let's remove it and if future
needs shows up we could consider to have a get/put API instead.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The pm_genpd_syscore_poweroff() API and pm_genpd_syscore_poweron() API
makes the pm_genpd_syscore_switch() API redundant.

Moreover, since there are no active users, let's just remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

CONFIG_PM_GENERIC_DOMAINS depends on CONFIG_PM, thus there are no need
to check explicity for it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The genpd dev_irq_safe configuration somewhat overlaps with the runtime
PM pm_runtime_irq_safe() option. Also, currently genpd don't have a
good way to deal with these device. So, until we figured out if and how
to support this in genpd, let's remove the option to configure it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There no users of these callbacks, let's simplify the generic power
domain by removing them.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In a step of simplifying the generic power domain let's move away from
using these callbacks.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are no users of these APIs. To simplify the generic power domain
let's remove them.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>