If the kernel is built to support multi-ARM configuration with shmobile
support built in, then drivers/sh is not built. This contains the PM
runtime code in drivers/sh/pm_runtime.c, which implicitly enables the
module clocks for all devices, and thus is quite essential.
Without this, the state of clocks depends on implicit reset state, or on
the bootloader.

If ARCH_SHMOBILE_MULTI then build the drivers/sh directory, but ensure that
bits that may conflict (drivers/sh/clk if the common clock framework is
enabled) or are not used (drivers/sh/intc), are not built.
Also, only enable the PM runtime code when actually running on a shmobile
SoCs that needs it.

ARCH_SHMOBILE_MULTI was added a while ago by commit
efacfce5 ("ARM: shmobile: Introduce
ARCH_SHMOBILE_MULTI"), but drivers/sh was compiled for both
ARCH_SHMOBILE_LEGACY and ARCH_SHMOBILE_MULTI until commit
bf98c1ea ("ARM: Rename ARCH_SHMOBILE to
ARCH_SHMOBILE_LEGACY").

Inspired by a patch from Ben Dooks <ben.dooks@codethink.co.uk>.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

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>

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The runtime PM platform support stub in use by ARM-based SH/R-Mobile
platforms contains nothing that's specifically ARM-related and instead of
wholly generic to anything using the clock framework.

The recent runtime PM changes interact rather badly with the lazy
disabling of clocks late in the boot process through the clock framework,
leading to situations where the runtime suspend/resume paths are entered
without a clock being actively driven due to having been lazily gated
off.

In order to correct this we can trivially tie in the aforementioned stub
as a general fallback for all SH platforms that don't presently have
their own runtime PM implementations (the corner case being SH-based
SH-Mobile platforms, which have their own stub through the hwblk API --
which in turn has bitrotted and will be subsequently adapted to use the
same stub as everyone else), regardless of whether the platforms choose
to define power domains of their own or not.

This fixes up regressions for clock framework users who also build in
runtime PM support without any specific power domains of their own, which
was previously causing the serial console to be lost when warring with
lazy clock disabling.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Since the PM clock management code in drivers/base/power/clock_ops.c
is used for both runtime PM and system suspend/hibernation, the
definitions of data structures and headers related to it should not
be located in include/linux/pm_rumtime.h.  Move them to a separate
header file.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Make shmobile use pm_genpd_poweroff_unused() instead of the
open-coded powering off PM domains without devices in use.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

Add a mach-shmobile specific callback for SoC-specific code
to hook into. By having the late_initcall() in a common place
we can have multi-SoC/board support in the same kernel binary.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The common PM clock management functions may be used for system
suspend/resume as well as for runtime PM, so rename them
accordingly.  Modify kerneldoc comments describing these functions
and kernel messages printed by them, so that they refer to power
management in general rather that to runtime PM.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: NKevin Hilman <khilman@ti.com>

The naming convention used by commit 7538e3db6e015e890825fbd9f86599b
(PM: Add support for device power domains), which introduced the
struct dev_power_domain type for representing device power domains,
evidently confuses some developers who tend to think that objects
of this type must correspond to "power domains" as defined by
hardware, which is not the case.  Namely, at the kernel level, a
struct dev_power_domain object can represent arbitrary set of devices
that are mutually dependent power management-wise and need not belong
to one hardware power domain.  To avoid that confusion, rename struct
dev_power_domain to struct dev_pm_domain and rename the related
pointers in struct device and struct pm_clk_notifier_block from
pwr_domain to pm_domain.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NKevin Hilman <khilman@ti.com>

Many different platforms and subsystems may want to disable device
clocks during suspend and enable them during resume which is going to
be done in a very similar way in all those cases.  For this reason,
provide generic routines for the manipulation of device clocks during
suspend and resume.

Convert the ARM shmobile platform to using the new routines.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Some subsystems need to attach PM-related data to struct device and
they need to use devres for this purpose.  For their convenience
and to make code more straightforward, add a new field called
subsys_data to struct dev_pm_info and let subsystems use it for
attaching PM-related information to devices.

Convert the ARM shmobile platform to using the new field.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

shmobile platforms replace the runtime PM callbacks of the platform
bus type with their own routines, but this means that the callbacks
are replaced system-wide.  This may not be the right approach if the
platform devices on the system are not of the same type (e.g. some
of them belong to an SoC and the others are located in separate
chips), because in those cases they may require different handling.
Thus it is better to use power domains to override the platform bus
type's PM handling, as it generally is possible to use different
power domains for devices with different PM requirements.

Define a default power domain for shmobile in both the SH and ARM
falvors and use it to override the platform bus type's PM callbacks.
Since the suspend and hibernate callbacks of the new "default" power
domains need to be the same and the platform bus type's suspend and
hibernate callbacks for the time being, export those callbacks so
that can be used outside of the platform bus type code.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

This is the SH-Mobile ARM Runtime PM implementation V3.
Only clocks are managed at this point. If Runtime PM
is disabled then the clocks will be enabled before
->probe() and disabled after ->remove().
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>