A recursive lockdep warning occurs if you call
regulator_set_optimum_mode() on a regulator with a supply because
there is no nesting annotation for the rdev->mutex. To avoid this
warning, get the supply's load before locking the regulator's
mutex to avoid grabbing the same class of lock twice.

=============================================
[ INFO: possible recursive locking detected ]
3.4.0 #3257 Tainted: G        W
---------------------------------------------
swapper/0/1 is trying to acquire lock:
 (&rdev->mutex){+.+.+.}, at: [<c036e9e0>] regulator_get_voltage+0x18/0x38

but task is already holding lock:
 (&rdev->mutex){+.+.+.}, at: [<c036ef38>] regulator_set_optimum_mode+0x24/0x224

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&rdev->mutex);
  lock(&rdev->mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by swapper/0/1:
 #0:  (&__lockdep_no_validate__){......}, at: [<c03dbb48>] __driver_attach+0x40/0x8c
 #1:  (&__lockdep_no_validate__){......}, at: [<c03dbb58>] __driver_attach+0x50/0x8c
 #2:  (&rdev->mutex){+.+.+.}, at: [<c036ef38>] regulator_set_optimum_mode+0x24/0x224

stack backtrace:
[<c001521c>] (unwind_backtrace+0x0/0x12c) from [<c00cc4d4>] (validate_chain+0x760/0x1080)
[<c00cc4d4>] (validate_chain+0x760/0x1080) from [<c00cd744>] (__lock_acquire+0x950/0xa10)
[<c00cd744>] (__lock_acquire+0x950/0xa10) from [<c00cd990>] (lock_acquire+0x18c/0x1e8)
[<c00cd990>] (lock_acquire+0x18c/0x1e8) from [<c080c248>] (mutex_lock_nested+0x68/0x3c4)
[<c080c248>] (mutex_lock_nested+0x68/0x3c4) from [<c036e9e0>] (regulator_get_voltage+0x18/0x38)
[<c036e9e0>] (regulator_get_voltage+0x18/0x38) from [<c036efb8>] (regulator_set_optimum_mode+0xa4/0x224)
...
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Properly handle the case if the specified min_uV is less than the voltage given
by the lowest selector.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
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>

If we fail while registering a regulator make sure we release the supply
for the regulator if there is one.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>
Cc: stable@vger.kernel.org

Integer division may truncate the result.
Use DIV_ROUND_UP to ensure simple linear voltage mappings falls within the
specified range.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

A lot of regulator hardware maps selectors on to voltages with a simple
linear mapping function

    selector = base + (selector * step size)

Provide off the shelf list_voltage() and map_voltage() operations which
use new min_uV and uV_step members in the regulator_desc to implement
this function.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

In order to allow more drivers to factor things out into data allow
drivers to provide a mapping function to convert voltages into selectors.
This allows any driver to use set_voltage_sel(). The existing mapping
based on iterating over list_voltage() is provided as an operation which
can be assigned to the new map_voltage() function though for ease of
transition it is treated as the default.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

The core really wants a struct device to be supplied for regulators and
there's no reason this should be impossible so provide one so complain
if we didn't get one.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

It turns out that (quite surprisingly) devres_destroy() only undoes the
devres mapping, it doesn't destroy the underlying resource, meaning that
anything using devm_regulator_put() would leak. While we wait for the new
devres_release() which does what we want to get merged open code it in
devm_regulator_put().
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

If a regulator is always on for any reason then cache that when the
consumer is created and use it to optimise away the need to take locks
or recurse up the supply tree when consumers do enable or disable calls.
The scheduling of asynchronous work for bulk enables is also skipped.

We don't actually check if the device physically supports control on the
basis that constraints allowing status changes on physically always on
regulators are nonsensical anyway.

This is a very common pattern in hardware - it's normal to have some
power supplies that have either no software control or are critical to
system function - so many systems should be able to benefit.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

regulator_set_optimum_mode needs set_mode to properly work.
Add checking for set_mode callback in case it may be not implemented.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Since the enable(), disable() and is_enabled() operations for most regmap
based regulators come down to reading and updating a single register bit
we can factor out the code and allow these drivers to just define which
bit to update using the enable_reg and enable_mask fields in their desc
and then use operations provided by the core.

As well as the code saving this opens the door to future optimisation of
the bulk operations - if the core can realise that we are updating a
single register for multiple regulators then it should be able to combine
these updates into a single physical operation.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

Since the voltage selector operations are intended to directly map a
bitfield in the device register map into regulator API operations the
code for implementing them is usually very standard we can save some
code by providing standard implementations for devices using the regmap
API.

Drivers using regmap can pass their regmap in in the regmap_config
struct, set vsel_reg and vsel_mask in their regulator_desc and then
use regulator_{get,set}_voltage_sel_regmap in their ops. This saves
a small amount of code from each driver.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

Since many regulators use regmap for register I/O and since there's quite
a few very common patterns in the code allow drivers to pass in a regmap
to the core for use in generic code.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

In current implementation, to support set_suspend_voltage and set_suspend_mode
the regulator code needs the regulator driver to implement both
set_suspend_enable and set_suspend_disable callbacks.

This patch removes this limitation. In the case set_suspend_enable and/or
set_suspend_disable are NULL, the regulator code assumes we don't need to
do any thing to enable/disable regulator when system is suspended and
then will continue to handle set_suspend_mode and set_suspend_voltage.

Currently the regulator core creates suspend state related sysfs entries only
if both set_suspend_enable and set_suspend_disable callbacks are not NULL.
A side-effect of this change is that the regulator core will create suspend
state related sysfs entries unconditionally now.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When supplied by another regulator, returns the supply regulator's output
voltage for inpu_uV.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We don't support missing configs at all so segfaulting isn't that bad
but since we've got checks in the code move the dereference after them.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Rather than adding new arguments to regulator_register() every time we
want to add a new bit of dynamic information at runtime change the function
to take these via a struct. By doing this we avoid needing to do further
changes like the recent addition of device tree support which required each
regulator driver to be updated to take an additional parameter.

The regulator_desc which should (mostly) be static data is still passed
separately as most drivers are able to configure this statically at build
time.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

In currently implementation of _regulator_do_set_voltage, set_voltage_time_sel will
only be called if set_voltage_sel is implemented.

set_voltage_time_sel actually only needs get_voltage_sel to get old_selector.

This patch makes regulator core support set_voltage_time_sel for drivers
implement either set_voltage or set_voltage_sel.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Drivers should be able to declare their descriptors const and the framework
shouldn't ever be modifying the desciptor. Make the parameter and the
pointer in regulator_dev const to enforce this.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Ensure we always apply the supply mapping when doing a lookup rather than
only doing it in non-DT cases, ensuring that regulators with supplies
specified in the regulator_desc can find their supplies on non-DT systems
and generally making the code more obvious.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When using device tree if there's no binding for a supply then there's no
way that one could appear later so just fail permanently right away. This
avoids wasting time trying to reprobe when that can never work.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When cleaning up after a failed bulk_disable() we try to reenable any
supplies that we did manage to disable - complain if we fail to do that
when we try.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If a regulator with a supply is being unregistered we will call
regulator_put() to release the supply with the regulator_list_mutex held
but this deadlocks as regulator_put() takes the same lock. Fix this by
releasing the supply before we take the mutex in regulator_unregister().
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

of_parse_phandle() returns NULL either if the property name
itself does not exist or if it (exists and) does not
reference a valid phandle.
Giving out a warn like the one below (that the property references
an invalid phandle) can be confusing when the property itself
does not exist in the node.
Fix it with a more sensible message and make it a dev_dbg instead
of a dev_warn.
Reported-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If we fail to locate a requested regulator return -EPROBE_DEFER. If drivers
pass this error code through to their caller (which they really should)
then this will ensure that the probe is retried later when further devices
become available.  In the unusual case where a driver doesn't want this
it can override the default behaviour.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NLiam Girdwood <lrg@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

rdev->desc->ops->set_voltage_time_sel may return negative error code.
Set delay to 0 and also show warning if set_voltage_time_sel returns error.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If CONFIG_DEBUG_FS=y debugfs functions will never return an
ERR_PTR. Instead they'll return NULL. The intent is to remove
ifdefs in calling code.

Update the code to reflect this. We gain an extra dentry pointer
per struct regulator and struct regulator_dev but that should be
ok because most distros have debugfs compiled in anyway.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Use IS_ERR_OR_NULL() rather than open coding it and ignore errors from
failure to create the supply map.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Start unwind from the point the error happens instead of iterating over all
consumers, then unwind code can be simpler.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

consumer_dev is remove by commit 737f36
"regulator: Remove support for supplies specified by struct device".
Thus remove the obsolete comment.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It doesn't make much sense to specify a range of voltages consumers can
use if they haven't been given permission to change the voltage. Log if
this happens, probably the user forgot to specify CHANGE_VOLTAGE.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

Liam pointed out via IM that since we now use the pure function name for
all regulator logging a lot of the messages such as those logging the
constraints are getting a bit noisy due to the implementation detail
that is the function name:

print_constraints: VDDARM: 1000 <--> 1300 mV at 1300 mV at 0 mA

In discussion it seemed like the best thing was to just drop the pr_fmt
and clarify individual log messages where there is an issue otherwise
we get into silly things like renaming the functions to suit the logging.

This is mostly an issue as we have a moderate amount of non-error logging
in the boot sequence to aid debug if something goes wrong since regulator
misconfiguration can kill the system pretty quickly.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

This has been deprecated for a very long time now.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NLiam Girdwood <lrg@ti.com>

Often there is a need for disabling a set of regulators in order opposite
to the enable order. Currently the function regulator_bulk_disable() walks
list of regulators in same order as regulator_bulk_enable(). This may cause
trouble, especially for devices with mixed analogue and digital circuits.
So reverse the disabling sequence of regulator_bulk_disable().
While at it, also correct the comment.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Commit 5bc75a88 ("kernel-doc: fix new warning in regulator core")
added documentation for of_node to address a warning but the
documentation didn't explain what the parameter is for so would be
likely to be unhelpful for users.  Clarify that.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix new kernel-doc warning:

Warning(drivers/regulator/core.c:2741): No description found for parameter 'of_node'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc:	Liam Girdwood <lrg@ti.com>
Cc:	Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allow drivers to benefit from both the bulk APIs and managed resources
simultaneously.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Allow consumers to free regulators allocated using devm_regulator_get()
if they need to. This will not normally be required.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Add a resource managed regulator_get() to simplify regulator
usage in drivers. This allows driver authors to "get and forget"
about their regulators by automatically calling regulator_put()
when the driver is detached.

[Fixed up a couple of coding style issues -- broonie]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>