On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
two devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.

Introduce new function regulator_balance_voltage(), which
keeps max_spread constraint fulfilled between a group of coupled
regulators. It should be called if a regulator changes its
voltage or after disabling or enabling. Disabled regulators should
follow changes of the enabled ones, but their consumers' demands
shouldn't be taken into account while calculating voltage of other
coupled regulators.

Find voltages, which are closest to suiting all the consumers' demands,
while fulfilling max_spread constraint, keeping the following rules:
- if one regulator is about to rise its voltage, rise others
  voltages in order to keep the max_spread
- if a regulator, which has caused rising other regulators, is
  lowered, lower other regulators if possible
- if one regulator is about to lower its voltage, but it hasn't caused
  rising other regulators, don't change its voltage if it breaks the
  max_spread

Change regulators' voltages step by step, keeping max_spread constraint
fulfilled all the time. Function regulator_get_optimal_voltage()
should find the best possible change for the regulator, which doesn't
break max_spread constraint. In function regulator_balance_voltage()
optimize number of steps by finding highest voltage difference on
each iteration.

If a regulator, which is about to change its voltage, is not coupled,
method regulator_get_optimal_voltage() should simply return the lowest
voltage fulfilling consumers' demands.

Coupling should be checked only if the system is in PM_SUSPEND_ON state.
Signed-off-by: NMaciej Purski <m.purski@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
two devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.

Fill coupling descriptor with data obtained from DTS using previously
defined of_functions. Fail to register a regulator, if some data
inconsistency occurs. If some coupled regulators are not yet registered,
don't fail to register, but try to resolve them in late init call.
Signed-off-by: NMaciej Purski <m.purski@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Setting voltage, enabling/disabling regulators requires operations on
all regulators related with the regulator being changed. Therefore,
all of them should be locked for the whole operation. With the current
locking implementation, adding additional dependency (regulators
coupling) causes deadlocks in some cases.

Introduce a possibility to attempt to lock a mutex multiple times
by the same task without waiting on a mutex. This should handle all
reasonable coupling-supplying combinations, especially when two coupled
regulators share common supplies. The only situation that should be
forbidden is simultaneous coupling and supplying between a pair of
regulators.

The idea is based on clk core.
Signed-off-by: NMaciej Purski <m.purski@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Regulators attached via RPMh on Qualcomm sdm845 apparently are
write-only.  Specifically you can send a request for a certain voltage
but you can't read back to see what voltage you've requested.  What
this means is that at bootup we have absolutely no idea what voltage
we could be at.

As discussed in the patches to try to support the RPMh regulators [1],
the fact that regulators are write-only means that its driver's
get_voltage_sel() should return an error code if it's called before
any calls to set_voltage_sel().  This causes problems in
machine_constraints_voltage() when trying to apply the constraints.

A proposed fix was to come up with an error code that could be
returned by get_voltage_sel() which would cause the regulator
framework to simply try setting the voltage with the current
constraints.

In this patch I propose the error code -ENOTRECOVERABLE.  In errno.h
this error is described as "State not recoverable".  Though the error
code was originally intended "for robust mutexes", the description of
the error code seems to apply here because we can't read the state of
the regulator.  Also note that the only existing user of this error
code in the regulator framework is tps65090-regulator.c which returns
this error code from the enable() call (not get_voltage() or
get_voltage_sel()), so there should be no existing regulators that
might accidentally get the new behavior.  (Side note is that tps65090
seems to interpret this error code to mean an error that you can't
recover from rather than some data that can't be recovered).

[1] https://patchwork.kernel.org/patch/10340897/Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Signed-off-by: NMark Brown <broonie@kernel.org>

When resuming from idle with the new suspend mode configuration support
we go through the resume callbacks with a state of PM_SUSPEND_TO_IDLE
which we don't have regulator constraints for, causing an error:

    dpm_run_callback(): regulator_resume_early+0x0/0x64 returns -22
    PM: Device regulator.0 failed to resume early: error -22

Avoid this and similar errors by treating missing constraints as a noop.

See also commit 57a0dd18 ("regulator: Fix suspend to idle"),
which fixed the suspend part.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

We are currently passing a GPIO number from the global GPIO numberspace
into the regulator core for handling enable GPIOs. This is not good
since it ties into the global GPIO numberspace and uses gpio_to_desc()
to overcome this.

Start supporting passing an already initialized GPIO descriptor to the
core instead: leaf drivers pick their descriptors, associated directly
with the device node (or from ACPI or from a board descriptor table)
and use that directly without any roundtrip over the global GPIO
numberspace.

This looks messy since it adds a bunch of extra code in the core, but
at the end of the patch series we will delete the handling of the GPIO
number and only deal with descriptors so things end up neat.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

When suspending to idle with the new suspend mode configuration support
we go through the suspend callbacks with a state of PM_SUSPEND_TO_IDLE
which we don't have regulator constraints for, causing an error.  Avoid
this and similar errors by treating missing constraints as a noop.
Reported-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>

3d67fe95 (regulator: core: Refactor regulator_list_voltage()) missed
one user of regulator_list_voltage(), update for that.
Signed-off-by: NMark Brown <broonie@kernel.org>

Change _regulator_list_voltage() argument from regulator to
regulator_dev in order to provide better separation of core layers.
Allow calling _regulator_list_voltage() from functions, with
regulator_dev argument. This refactoring is needed in order to
implement setting voltage of coupled regulators.
Signed-off-by: NMaciej Purski <m.purski@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

As of_find_regulator_by_node() is an of function it should be moved from
core.c to of_regulator.c. It provides better separation of device tree
functions from the core and allows other of_functions in of_regulator.c
to resolve device_node to regulator_dev. This will be useful for
implementation of parsing coupled regulators properties.

Declare of_find_regulator_by_node() function in internal.h as well as
regulator_class and dev_to_rdev(), as they are needed by
of_find_regulator_by_node().
Signed-off-by: NMaciej Purski <m.purski@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

In this patch, consumers are allowed to set suspend voltage, and this
actually just set the "uV" in constraint::regulator_state, when the
regulator_suspend_late() was called by PM core through callback when
the system is entering into suspend, the regulator device would act
suspend activity then.

And it assumes that if any consumer set suspend voltage, the regulator
device should be enabled in the suspend state.  And if the suspend
voltage of a regulator device for all consumers was set zero, the
regulator device would be off in the suspend state.

This patch also provides a new function hook to regulator devices for
resuming from suspend states.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Regualtor suspend/resume functions should only be called by PM suspend
core via registering dev_pm_ops, and regulator devices should implement
the callback functions.  Thus, any regulator consumer shouldn't call
the regulator suspend/resume functions directly.

In order to avoid compile errors, two empty functions with the same name
still be left for the time being.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The items "disabled" and "enabled" are a little redundant, since only one
of them would be set to record if the regulator device should keep on
or be switched to off in suspend states.

So in this patch, the "disabled" was removed, only leave the "enabled":
  - enabled == 1 for regulator-on-in-suspend
  - enabled == 0 for regulator-off-in-suspend
  - enabled == -1 means do nothing when entering suspend mode.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Some regulator consumers would like to make the regulator device
keeping a voltage range output when the system entering into
suspend states.

Making regulator voltage be an array can allow consumers to set voltage
for normal state as well as for suspend states through the same code.
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Remove extraneous space to fix indentation on a couple of assignment
statements.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

A race condition between queueing and processing the disable_work
instances results in having a work instance in the queue and the
deferred_disables variable of regulator device structure having a
value '0'. If no new regulator_disable_deferred() call later from
clients, the deferred_disables variable value remains '0' and hits
BUG() in regulator_disable_work() when the queued instance scheduled
for processing the work.

The race occurs as below:

	Core-0					     Core-1
	.....	       /* deferred_disables = 2 */   .....
	.....	       /* disable_work is queued */  .....
	.....					     .....
regulator_disable_deferred: 		regulator_disable_work:
   mutex_lock(&rdev->mutex);			     .....
   rdev->deferred_disables++;		             .....
   mutex_unlock(&rdev->mutex);			     .....
   queue_delayed_work(...)		    mutex_lock(&rdev->mutex);
	.....				    count =rdev->deferred_disables;
	.....				    rdev->deferred_disables = 0;
	.....					     .....
	.....				    mutex_unlock(&rdev->mutex);
	.....					     .....
	.....				    return;
	.....					     .....
	/* No new regulator_disable_deferred() calls from clients */
	/* The newly queued instance is scheduled for processing */
	.....					     .....
regulator_disable_work:
	.....
   mutex_lock(&rdev->mutex);
   BUG_ON(!rdev->deferred_disables); /* deferred_disables = 0 */

The race is fixed by removing the work instance that is queued while
processing the previous queued instance. Cancel the newly queued instance
from disable_work() handler just after reset the deferred_disables variable
to value '0'. Also move the work queueing step before mutex_unlock in
regulator_disable_deferred().

Also use mod_delayed_work() in the pace of queue_delayed_work() as
queue_delayed_work() always uses the delay requested in the first call
when multiple consumers call regulator_disable_deferred() close in time
and does not guarantee the semantics of regulator_disable_deferred().
Signed-off-by: NTirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: NRob Herring <robh@kernel.org>
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now the debugfs file supply_map has a size limit PAGE_SIZE and the user
can not see the whole content of regulator_map_list when it is larger
than this limit.

This patch uses seq_file instead to make sure supply_map shows the full
information of regulator_map_list.
Signed-off-by: NHaishan Zhou <zhssmail@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Some regulators support get_voltage() and some support get_voltage_sel()
operations but currently we only propagate changes if the regulator has
a get_voltage() operation.  Also do this if we've got get_voltage_sel()

[Rewite commit message for clarity -- broonie]
Signed-off-by: NTirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Currently, when looking up a regulator supply, the regulator name
takes priority over the consumer mappings. As there are a lot of
regulator names that are in fairly common use (VDD, MICVDD, etc.) this
can easily lead to obtaining the wrong supply, when a system contains
two regulators that share a name.

The explicit consumer mappings contain much less ambiguity as they
specify both a name and a consumer device. As such prioritise those if
one exists and only fall back to the regulator name if there are no
matching explicit mappings.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Some regulators have different settling times for voltage increases and
decreases. To avoid a time penalty on the faster transition allow for
different settings for up- and downward transitions.
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Rather than just not resolving the supply when there is explicitly no
supply mapping fall through and allow a dummy supply to be substituted.
This fixes issues with constant retries reported by Dong Aisheng.
Signed-off-by: NMark Brown <broonie@kernel.org>
Tested-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>

When we are propagating voltage changes to parent regulators don't
bother if the parent does not have permission to change voltages.  This
simplifies error checking in the function for cases where the regulator
lacks some of the voltage operations.
Reported-by: NDong Aisheng <aisheng.dong@nxp.com>
Tested-by: NDong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Some regulators (some PWM regulators) have the voltage transition
non-linear i.e. exponentially. On such cases, the settling time
for voltage transition can not be presented in the voltage-ramp-delay.

Add new property for non-linear voltage transition and handle this
in getting the voltage settling time.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Commit 26988efe ("regulator: core: Allow to get voltage count and
list from parent") introduces the propagation of the parent voltage
count and list for regulators that don't provide this information
themselves. The goal is to support simple switch regulators, however as
a side effect normal continuous regulators can leak details of their
supplies and provide consumers with inconsistent information.

Limit the propagation of the voltage count and list to switch
regulators.

Fixes: 26988efe ("regulator: core: Allow to get voltage count and
  list from parent")
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Tested-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Remove the description for the non-existing 'ret' to fix the build warning:
./drivers/regulator/core.c:1467: warning:
Excess function parameter 'ret' description in 'regulator_dev_lookup'.
The description found for the return value is: @ret: 0 on success, -ENODEV
if lookup fails permanently, -EPROBE_DEFER if lookup could succeed in the future.
Signed-off-by: NTamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This is useful for devices, which need some time to start up, to help
the drivers track how long the supply has been up already. Ie whether
it can safely talk to the HW or needs to wait.
Signed-off-by: NHarald Geyer <harald@ccbib.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The supply_name member of struct regulator can be const as we
don't change it in the regulator core. Furthermore, when we copy
the supply name we can use kstrdup_const() here to avoid a copy
if the name is in the ro data section.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

When creating the link to the device sysfs entry, the regulator core
calls scnprintf() and then checks if the returned value is greater or
equal than the buffer size.

The former can never happen as scnprintf() returns the number of bytes
that were actually written to the buffer, not the bytes that *would*
have been written.

Use the right function in this case: snprintf().
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

After commit 66d228a2 ("regulator: core: Don't use regulators as
supplies until the parent is bound"), input supplies aren't resolved
if the input supplies parent device has not been bound. This prevent
regulators to hold an invalid reference if its supply parent device
driver probe is deferred.

But this causes issues on some boards where a PMIC's regulator use as
input supply a regulator from another PMIC whose driver is registered
after the driver for the former.

In this case the regulators for the first PMIC will fail to resolve
input supplies on regulators registration (since the other PMIC wasn't
probed yet). And when the core attempts to resolve again latter when
the other PMIC registers its own regulators, it will fail again since
the parent device isn't bound yet.

This will cause some parent supplies to never be resolved and wrongly
be disabled on boot due taking them as unused.

To solve this problem, also attempt to resolve the pending regulators
input supplies before disabling the unused regulators.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

It is allowed to call regulator_get with a NULL dev argument
(_regulator_get explicitly checks for it) but this causes an error later
when printing /sys/kernel/debug/regulator_summary.

Fix this by explicitly handling "deviceless" consumers in the debugfs code.
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

The code in _regulator_get() got a bit confusing over time, with control
flow jumping to a label from couple of places. Let's untangle it a bit by
doing the following:

1. Make handling of missing supplies and substituting them with dummy
regulators more explicit:

- check if we not have full constraints and refuse considering dummy
  regulators with appropriate message;

- use "switch (get_type)" to handle different types of request explicitly
  as well. "Normal" requests will get dummies, exclusive will not and
  will notify user about that; optional will fail silently.

2. Stop jumping to a label in the middle of the function but instead have
proper conditional flow. I believe jumps should be reserved for error
handling, breaking from inner loop, or restarting a loop, but not for
implementing normal conditional flow.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Instead of returning both regulator_dev structure as return value and
auxiliary error code in 'ret' argument, let's switch to using ERR_PTR
encoded values. This makes it more obvious what is going on at call sites.

Also, let's not unlock the mutex in the middle of a loop, but rather break
out and have single unlock path.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

"re-enable" was misspelled as "reename".
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is no need to have two loops there, we can store error for subsequent
reporting.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Instead of separate "exclusive" and "allow_dummy" arguments, that formed 3
valid combinations (normal, exclusive and optional) and an invalid one,
let's accept explicit "get_type", like we did in devm-managed code.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is no point in assigning value to 'ret' before calling
regulator_dev_lookup() as it will clobber 'ret' anyway.

Also, let's explicitly return -PROBE_DEFER when try_module_get() fails,
instead of relying that earlier initialization of "regulator" carries
correct value.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

When regulators are successfully registered, we check to see if the
regulator is a supply for any other registered regulator and if so
add the new regulator as the supply for the existing regulator(s).

Some devices, such as Power Management ICs, may register a series of
regulators when probed and there are cases where one of the regulators
may fail to register and defer the probing of the parent device. In this
case any successfully registered regulators would be unregistered so
that they can be re-registered at some time later when the probe is
attempted again. However, if one of the regulators that was registered
was added as a supply to another registered regulator (that did not
belong to the same parent device), then this supply regulator was
unregister again because the parent device is probe deferred, then a
regulator could be holding an invalid reference to a supply regulator
that has been unregistered. This will lead to a system crash if that
regulator is then used.

Although it would be possible to check when unregistering a regulator
if any other regulator in the system is using it as a supply, it still
may not be possible to remove it as a supply if this other regulator is
in use. Therefore, fix this by preventing any regulator from adding
another regulator as a supply if the parent device for the supply
regulator has not been bound and if the parent device for the supply
and the regulator are different. This will allow a parent device that is
registering regulators to be probe deferred and ensure that none of the
regulators it has registered are used as supplies for any other
regulator from another device.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This adds a trailing newline to a debug message.
Signed-off-by: NDavid Lechner <david@lechnology.com>
Signed-off-by: NMark Brown <broonie@kernel.org>