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>

Mostly scripted conversion of the smp_mb__* barriers.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Keep all power-domains already enabled by bootloader on, even if no
driver has claimed them. This is useful for debug and development, but
should not be needed on a platform with proper driver support.
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If devices don't provide latency data, this warning can be quite noisy until
the pm domain was enabled and disabled a few times. Turn this warning into
a debug message.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-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>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Cc: Len Brown <len.brown@intel.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0.  If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NKevin Hilman <khilman@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>

When genpd prepares for a system suspend it will fetch a runtime
reference for the device. When returning it we now use the
asyncronous runtime PM API. Thus we don't have to wait for the
device to become idle|suspended before we move on and handle the
next device in queue.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the asyncronous runtime PM API when returning the runtime
reference for the device after the system resume is completed.

By using the asyncronous runtime PM API we don't have to wait
for each an every device to become idle|suspended. Instead we
can move on and handle the next device in queue.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There's no need to test whether a (delayed) work item is pending
before queueing, flushing or cancelling it, so remove work_pending()
tests used in those cases.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make the generic PM domains pm_genpd_poweroff() function take
device PM QoS flags into account when deciding whether or not to
remove power from the domain.

After this change the routine will return -EBUSY without executing
the domain's .power_off() callback if there is at least one PM QoS
flags request for at least one device in the domain and at least of
those request has at least one of the NO_POWER_OFF and REMOTE_WAKEUP
flags set.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NJean Pihet <j-pihet@ti.com>
Reviewed-by: Nmark gross <markgross@thegnar.org>

If pm_genpd_attach_cpudidle failed we leak memory stored in 'cpu_data'.
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Function genpd_start_dev_no_timing was accessed inside CONFIG_PM_RUNTIME
macro but defined outside it. When the above macro was not defined the
compiler gave the following warning:

drivers/base/power/domain.c:96:12: warning:
‘genpd_start_dev_no_timing’ defined but not used [-Wunused-function]
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Make it possible to use domain names in operations connecting cpuidle
to and disconnecting it from a PM domain.  This is useful on
platforms where PM domain objects are organized in such a way that
the names of the domains are easier to use than the addresses of
those objects.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The names of the cpuidle-related functions in
drivers/base/power/domain.c are inconsistent with the names of the
other exported functions in that file (the "pm_" prefix is missing
from them) and they are missing kerneldoc comments.

Fix that by adding the missing "pm_" prefix to the names of those
functions and add kerneldoc comments documenting them.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

It sometimes is necessary to turn on a given PM domain when only
the name of it is known and the domain pointer is not readily
available.  For this reason, add a new helper function,
pm_genpd_name_poweron(), allowing the caller to turn on a PM domain
using its name for identification.  To avoid code duplication,
move the domain lookup code to a separate function.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Add a new helper function, pm_genpd_add_subdomain_names(), allowing
the caller to add a subdomain to a generic PM domain using names for
domain identification (both domains have to be initialized before).

This function is useful for adding subdomains to PM domains whose
representations are stored in tables, when the caller doesn't know
the indices of the domain to add the subdomain to and of the
subdomain itself, but it knows the domains' names.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Add a new helper function __pm_genpd_name_add_device() allowing
a device to be added to a (registered) generic PM domain identified
by name.  Add a wrapper around it, pm_genpd_name_add_device(),
passing NULL as the last argument and reorganize pm_domains.h for the
new functions to be defined consistently with the existing ones.

These functions are useful for adding devices to PM domains whose
representations are stored in tables, when the caller doesn't know
the index of the domain to add the device to, but it knows the
domain's name.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The syscore device PM flag used to mark the devices (belonging to
PM domains) that should never be turned off, except for the system
core (syscore) suspend/hibernation and resume stages, need not be
accessed by the runtime PM core functions, because all of the devices
it is set for need to be marked as "irq safe" anyway and are
protected from being turned off by runtime PM by ensuring that their
usage counters are always set.

For this reason, make the syscore flag system-wide PM-specific
and simplify the code used for manipulating it, because it need not
acquire the device's power.lock any more.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The genpd_start_dev() routine used by pm_genpd_runtime_resume()
to put "irq safe" devices into the full power state measures the
time necessary to "start" the device and updates its PM QoS timing
data if necessary.  This may lead to a deadlock if the given device
is a clock source and genpd_start_dev() is invoked from within the
clock source's .enable() routine, which will happen if that routine
uses pm_runtime_get_sync(), for example, to ensure that the device
is operational.

For this reason, introduce a special routine analogous to
genpd_start_dev(), called genpd_start_dev_no_timing(), that doesn't
carry out the time measurement, and make pm_genpd_runtime_resume()
use it instead of genpd_start_dev() to power up "irq safe" devices.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The syscore device PM flag is used to mark the devices (belonging to
a PM domain) that should never be turned off, except for the system
core (syscore) suspend/hibernation and resume stages.  That flag is
stored in the device's struct pm_subsys_data object whose address is
available from struct device.  However, in some situations it may be
convenient to set that flag before the device is added to a PM
domain, so it is better to move it directly to the "power" member of
struct device.  Then, it can be checked by the routines in
drivers/base/power/runtime.c and drivers/base/power/main.c, which is
more straightforward.

This also reduces the number of dev_gpd_data() invocations in the
generic PM domains framework, so the overhead related to the syscore
flag is slightly smaller.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

The always_on device flag is used to mark the devices (belonging to
a PM domain) that should never be turned off, except for the system
core (syscore) suspend/hibernation and resume stages.  Change name
of that flag to "syscore" to better reflect its purpose.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

Introduce function pm_genpd_syscore_switch() and two wrappers around
it, pm_genpd_syscore_poweroff() and pm_genpd_syscore_poweron(),
allowing the callers to let the generic PM domains framework know
that the given device is not necessary any more and its PM domain
can be turned off (the former) or that the given device will be
required immediately, so its PM domain has to be turned on (the
latter) during the system core (syscore) stage of system suspend
(or hibernation) and resume.

These functions will be used for handling devices registered as
clock sources and clock event devices that belong to PM domains.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Introduce function pm_genpd_sync_poweron() for restoring domain power
during resume from system suspend and hibernation.  It can be much
simpler than pm_genpd_poweron(), because it doesn't have to care
about locking and it can skip many checks done by the latter.

Modify pm_genpd_resume_noirq() and pm_genpd_restore_noirq() to use
the new function.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The functions genpd_save_dev() and genpd_restore_dev() are not used
for CONFIG_PM_RUNTIME unset, so move them under an appropriate
#ifdef.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Fixes the following sparse warning:
drivers/base/power/domain.c:1679:55: warning: Using plain integer as NULL pointer
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>