Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We're going to be using these in quite a few places so factor out the
readable/writable/volatile/precious checks.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

CONFIG_REGMAP_I2C/SPI are set to m when selected by a tristate config
option that's set to m. The regmap modules don't specify a license, so
fail to link to regmap_init at load time, since that is EXPORT_SYMBOL_GPL.
Fix this by specifying a license for the regmap modules.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We no longer enumerate the bus types, we rely on the driver telling us
this on init.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

x86_64 size_t is not an int but the printf format specifier for size_t
should be an int.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Copy over the read parts of the ASoC debugfs implementation into regmap,
allowing users to see what the register values the device has are at
runtime. The implementation, especially the support for seeking, is
mostly due to Dimitris Papastamos' work in ASoC.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Allowing the implementation to be multi-file.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This is mainly intended to be used by devices which can dynamically
block register writes at runtime, for other devices there is usually
limited value.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Trace single register reads and writes, plus start/stop tracepoints for
the actual I/O to see where we're spending time. This makes it easy to
have always on logging without overwhelming the logs and also lets us take
advantage of all the context and time information that the trace subsystem
collects for us.

We don't currently trace register values for bulk operations as this would
add complexity and overhead parsing the cooked data that's being worked
with.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When doing a single register write we use work_buf for both the register
and the value with the buffer formatted for sending directly to the device
so we can just do a write() directly. This saves allocating a temporary
buffer if we can't do gather writes and is likely to be faster than doing
a gather write.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This is currently unused but we need to know which registers exist and
their properties in order to implement diagnostics like register map
dumps and the cache features.

We use callbacks partly because properties can vary at runtime (eg, through
access locks on registers) and partly because big switch statements are a
good compromise between readable code and small data size for providing
information on big register maps.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks.  This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.

This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.

However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.

Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.
Reported-by: NColin Cross <ccross@google.com>
Tested-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The local variable ret is defined twice in pm_genpd_poweron(), which
causes this function to always return 0, even if the PM domain's
.power_on() callback fails, in which case an error code should be
returned.

Remove the wrong second definition of ret and additionally remove an
unnecessary definition of wait from pm_genpd_poweron().
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

create_path() on something without a single / in it will return err
without initializing it.  It actually can't happen (we call that thing
only if create on the same path returns -ENOENT, which won't happen
happen for single-component path), but in this case initializing err
to 0 is more than making compiler to STFU - would be the right thing
to return on such paths; the function creates a parent directory of
given pathname and in that case it has no work to do...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dev_opp initial value shoule be ERR_PTR(), IS_ERR() is used to check
error.
Signed-off-by: NJonghwan Choi <jhbird.choi@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After we's done complete(&req->done), there's nothing to prevent the
scope containing *req from being gone and *req overwritten by any
kind of junk.  So we must read req->next before that...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We should be reading the number of bytes we were asked for, not the size
of a single register.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

There are many places in the tree where we implement register access for
devices on non-memory mapped buses, especially I2C and SPI. Since hardware
designers seem to have settled on a relatively consistent set of register
interfaces this can be effectively factored out into shared code.  There
are a standard set of formats for marshalling data for exchange with the
device, with the actual I/O mechanisms generally being simple byte
streams.

We create an abstraction for marshaling data into formats which can be
sent on the control interfaces, and create a standard method for
plugging in actual transport underneath that.

This is mostly a refactoring and renaming of the bottom level of the
existing code for sharing register I/O which we have in ASoC. A
subsequent patch in this series converts ASoC to use this.  The main
difference in interface is that reads return values by writing to a
location provided by a pointer rather than in the return value, ensuring
we can use the full range of the type for register data.  We also use
unsigned types rather than ints for the same reason.

As some of the devices can have very large register maps the existing
ASoC code also contains infrastructure for managing register caches.
This cache work will be moved over in a future stage to allow for
separate review, the current patch only deals with the physical I/O.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>

We do _NOT_ want to mkdir the path itself - we are preparing to
mknod it, after all.  Normally it'll fail with -ENOENT and
just do nothing, but if somebody has created the parent in
the meanwhile, we'll get buggered...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and give it a namespace where devtmpfs would be mounted on root,
thus avoiding abuses of vfs_path_lookup() (it was never intended to
be used with LOOKUP_PARENT).  Games with credentials are also gone.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Some users are apparently confused by dmesg output from
read_magic_time(), which looks like "real" time and date.
Add the "RTC" string to time stamps printed by read_magic_time() to
avoid that confusion.
Reported-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

cpufreq table allocated by opp_init_cpufreq_table is better
freed by OPP layer itself. This allows future modifications to
the table handling to be transparent to the users.
Signed-off-by: NNishanth Menon <nm@ti.com>
Acked-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Currently pm_genpd_poweroff() discards error codes returned by
the PM domain's .power_off() callback, because it's safer to always
regard the domain as inaccessible to drivers after a failing
.power_off().  Still, there are situations in which the low-level
code may want to indicate that it doesn't want to power off the
domain, so allow it to do that by returning -EBUSY from .power_off().
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

Make pd_power_down_a3rv() use genpd_queue_power_off_work() to queue
up the powering off of the A4LC domain to avoid queuing it up when
it is pending.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

Add a new function pm_genpd_poweroff_unused() queuing up the
execution of pm_genpd_poweroff() for every initialized generic PM
domain.  Calling it will cause every generic PM domain without
devices in use to be powered off.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@opensource.se>

The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

In theory it is possible that pm_genpd_poweroff() for two different
subdomains of the same parent domain will attempt to queue up the
execution of pm_genpd_poweroff() for the parent twice in a row.  This
would lead to unpleasant consequences, so prevent it from happening
by checking if genpd->power_off_work is pending before attempting to
queue it up.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Kevin points out that if there's a device that can wake up the system
from sleep states, but it doesn't generate wakeup signals by itself
(they are generated on its behalf by other parts of the system) and
it currently is not enabled to wake up the system (that is,
device_may_wakeup() returns "false" for it), we may need to change
its wakeup settings during system suspend (for example, the device
might have been configured to signal remote wakeup from the system's
working state, as needed by runtime PM).  Therefore the generic PM
domains code should invoke the system suspend callbacks provided by
the device's driver, which it doesn't do if the PM domain is powered
off during the system suspend's "prepare" stage.  This is a valid
point.  Moreover, this code also should make sure that system wakeup
devices that are enabled to wake up the system from sleep states and
have to remain active for this purpose are not suspended while the
system is in a sleep state.

To avoid the above issues, make the generic PM domains' .prepare()
routine, pm_genpd_prepare(), force runtime resume of devices whose
system wakeup settings may need to be changed during system suspend
or that should remain active while the system is in a sleep state to
be able to wake it up from that state.
Reported-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Since every device in a PM domain has its own need_restore
flag, which is set by __pm_genpd_save_device(), there's no need to
walk the domain's device list and restore all devices on an error
from one of the drivers' .runtime_suspend() callbacks.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

A deadlock may occur if one of the PM domains' .start_device() or
.stop_device() callbacks or a device driver's .runtime_suspend() or
.runtime_resume() callback executed by the core generic PM domain
code uses a "wrong" runtime PM helper function.  This happens, for
example, if .runtime_resume() from one device's driver calls
pm_runtime_resume() for another device in the same PM domain.
A similar situation may take place if a device's parent is in the
same PM domain, in which case the runtime PM framework may execute
pm_genpd_runtime_resume() automatically for the parent (if it is
suspended at the moment).  This, of course, is undesirable, so
the generic PM domains code should be modified to prevent it from
happening.

The runtime PM framework guarantees that pm_genpd_runtime_suspend()
and pm_genpd_runtime_resume() won't be executed in parallel for
the same device, so the generic PM domains code need not worry
about those cases.  Still, it needs to prevent the other possible
race conditions between pm_genpd_runtime_suspend(),
pm_genpd_runtime_resume(), pm_genpd_poweron() and pm_genpd_poweroff()
from happening and it needs to avoid deadlocks at the same time.
To this end, modify the generic PM domains code to relax
synchronization rules so that:

* pm_genpd_poweron() doesn't wait for the PM domain status to
  change from GPD_STATE_BUSY.  If it finds that the status is
  not GPD_STATE_POWER_OFF, it returns without powering the domain on
  (it may modify the status depending on the circumstances).

* pm_genpd_poweroff() returns as soon as it finds that the PM
  domain's status changed from GPD_STATE_BUSY after it's released
  the PM domain's lock.

* pm_genpd_runtime_suspend() doesn't wait for the PM domain status
  to change from GPD_STATE_BUSY after executing the domain's
  .stop_device() callback and executes pm_genpd_poweroff() only
  if pm_genpd_runtime_resume() is not executed in parallel.

* pm_genpd_runtime_resume() doesn't wait for the PM domain status
  to change from GPD_STATE_BUSY after executing pm_genpd_poweron()
  and sets the domain's status to GPD_STATE_BUSY and increments its
  counter of resuming devices (introduced by this change) immediately
  after acquiring the lock.  The counter of resuming devices is then
  decremented after executing __pm_genpd_runtime_resume() for the
  device and the domain's status is reset to GPD_STATE_ACTIVE (unless
  there are more resuming devices in the domain, in which case the
  status remains GPD_STATE_BUSY).

This way, for example, if a device driver's .runtime_resume()
callback executes pm_runtime_resume() for another device in the same
PM domain, pm_genpd_poweron() called by pm_genpd_runtime_resume()
invoked by the runtime PM framework will not block and it will see
that there's nothing to do for it.  Next, the PM domain's lock will
be acquired without waiting for its status to change from
GPD_STATE_BUSY and the device driver's .runtime_resume() callback
will be executed.  In turn, if pm_runtime_suspend() is executed by
one device driver's .runtime_resume() callback for another device in
the same PM domain, pm_genpd_poweroff() executed by
pm_genpd_runtime_suspend() invoked by the runtime PM framework as a
result will notice that one of the devices in the domain is being
resumed, so it will return immediately.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Currently, the .start_device() and .stop_device() callbacks from
struct generic_pm_domain() as well as the device drivers' runtime PM
callbacks used by the generic PM domains code are executed under
the generic PM domain lock.  This, unfortunately, is prone to
deadlocks, for example if a device and its parent are boths members
of the same PM domain.  For this reason, it would be better if the
PM domains code didn't execute device callbacks under the lock.

Rework the locking in the generic PM domains code so that the lock
is dropped for the execution of device callbacks.  To this end,
introduce PM domains states reflecting the current status of a PM
domain and such that the PM domain lock cannot be acquired if the
status is GPD_STATE_BUSY.  Make threads attempting to acquire a PM
domain's lock wait until the status changes to either
GPD_STATE_ACTIVE or GPD_STATE_POWER_OFF.

This change by itself doesn't fix the deadlock problem mentioned
above, but the mechanism introduced by it will be used for for this
purpose by a subsequent patch.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

If pm_generic_prepare() in pm_genpd_prepare() returns error code,
the PM domains counter of "prepared" devices should be decremented
and its suspend_power_off flag should be reset if this counter drops
down to zero.  Otherwise, the PM domain runtime PM code will not
handle the domain correctly (it will permanently think that system
suspend is in progress).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The runtime PM status of devices in a power domain that is not
powered off in pm_genpd_complete() should be set to "active", because
those devices are operational at this point.  Some of them may not be
in use, though, so make pm_genpd_complete() call pm_runtime_idle()
in addition to pm_runtime_set_active() for each of them.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Patch 2e711c04
(PM: Remove sysdev suspend, resume and shutdown operations)
deleted sysdev_suspend(), which was being relied on to call
check_wakeup_irqs() in suspend.  If check_wakeup_irqs() is not
called, wake interrupts that are pending when suspend is
entered may be lost.  It also breaks IRQCHIP_MASK_ON_SUSPEND,
which is handled in check_wakeup_irqs().

This patch adds a call to check_wakeup_irqs() in syscore_suspend(),
similar to what was deleted in sysdev_suspend().
Signed-off-by: NColin Cross <ccross@android.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Allow SoC-specific code to call pm_genpd_poweron().
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>