regulator: core: Propagate the regulator state in case of exclusive get

Previously, performing an exclusive get on an already-enabled regulator
resulted in inconsistent state initialization between child and parent
regulators. While the child's counts were updated, its parent's counters
remained unaffected.

Consequently, attempting to disable an already-enabled exclusive regulator
triggered unbalanced disables warnings from its parent regulator.

This commit addresses the issue by propagating the enable state to the
parent regulator using a regulator_enable call. This ensures consistent
state management across the regulator hierarchy, preventing warnings!

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://msgid.link/r/20240312091638.1266167-1-kory.maincent@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: make regulator_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the regulator_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://msgid.link/r/20240305-class_cleanup-regulator-v1-1-4950345d6d8f@marliere.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Remove redundant assignment to variable possible_uV

The variable possible_uV being assigned a value that is never read, the
control flow via the following goto statement takes a path where the
variable is not accessed. The assignment is redundant and can be removed.

Cleans up clang scan build warning:
drivers/regulator/core.c:3935:3: warning: Value stored to 'possible_uV'
is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://msgid.link/r/20240216134918.2108262-1-colin.i.king@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Remove redundant assignment to variable possible_uV

The variable possible_uV being assigned a value that is never read, the
control flow via the following goto statement takes a path where the
variable is not accessed. The assignment is redundant and can be removed.

Cleans up clang scan build warning:
drivers/regulator/core.c:3935:3: warning: Value stored to 'possible_uV'
is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://msgid.link/r/20240216134918.2108262-1-colin.i.king@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: event: Add regulator netlink event support

This commit introduces netlink event support to the regulator subsystem.

Changes:
- Introduce event.c and regnl.h for netlink event handling.
- Implement reg_generate_netlink_event to broadcast regulator events.
- Update Makefile to include the new event.c file.

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Link: https://lore.kernel.org/r/20231205105207.1262928-1-naresh.solanki@9elements.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: event: Add regulator netlink event support

This commit introduces netlink event support to the regulator subsystem.

Changes:
- Introduce event.c and regnl.h for netlink event handling.
- Implement reg_generate_netlink_event to broadcast regulator events.
- Update Makefile to include the new event.c file.

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Link: https://lore.kernel.org/r/20231205105207.1262928-1-naresh.solanki@9elements.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Only increment use_count when enable_count changes

The use_count of a regulator should only be incremented when the
enable_count changes from 0 to 1. Similarly, the use_count should
only be decremented when the enable_count changes from 1 to 0.

In the previous implementation, use_count was sometimes decremented
to 0 when some consumer called unbalanced disable,
leading to unexpected disable even the regulator is enabled by
other consumers. With this change, the use_count accurately reflects
the number of users which the regulator is enabled.

This should make things more robust in the case where a consumer does
leak references.

Signed-off-by: Rui Zhang <zr.zhang@vivo.com>
Link: https://lore.kernel.org/r/20231103074231.8031-1-zr.zhang@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add option to prevent disabling unused regulators

This may be useful for debugging and develompent purposes, when there are
drivers that depend on regulators to be enabled but do not request them.

It is inspired from the clk_ignore_unused and pd_ignore_unused parameters,
that are used to keep firmware-enabled clocks and power domains on even if
these are not used by drivers.

The parameter is not expected to be used in normal cases and should not be
needed on a platform with proper driver support.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20231107190926.1185326-1-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Implement uv_survival_time for handling under-voltage events

Add 'uv_survival_time' field to regulation_constraints for specifying
survival time post critical under-voltage event. Update the regulator
notifier call chain and Device Tree property parsing to use this new
field, allowing a configurable timeout before emergency shutdown.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20231026144824.4065145-6-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Introduce handling for system-critical under-voltage events

Handle under-voltage events for crucial regulators to maintain system
stability and avoid issues during power drops.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20231026144824.4065145-3-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator/core: Revert "fix kobject release warning and memory leak in regulator_register()"

This reverts commit 5f4b204b6b8153923d5be8002c5f7082985d153f.

Since rdev->dev now has a release() callback, the proper way of freeing
the initialized device can be restored.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/d7f469f3f7b1f0e1d52f9a7ede3f3c5703382090.1695077303.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator/core: regulator_register: set device->class earlier

When fixing a memory leak in commit d3c731564e09 ("regulator: plug
of_node leak in regulator_register()'s error path") it moved the
device_initialize() call earlier, but did not move the `dev->class`
initialization. The bug was spotted and fixed by reverting part of
the commit (in commit 5f4b204b6b81 "regulator: core: fix kobject
release warning and memory leak in regulator_register()") but
introducing a different bug: now early error paths use `kfree(dev)`
instead of `put_device()` for an already initialized `struct device`.

Move the missing assignments to just after `device_initialize()`.

Fixes: d3c731564e09 ("regulator: plug of_node leak in regulator_register()'s error path")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/b5b19cb458c40c9d02f3d5a7bd1ba7d97ba17279.1695077303.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Streamline debugfs operations

If CONFIG_DEBUG_FS is not set:

regulator: Failed to create debugfs directory
...
regulator-dummy: Failed to create debugfs directory

As per the comments for debugfs_create_dir(), errors returned by this
function should be expected, and ignored:

* If debugfs is not enabled in the kernel, the value -%ENODEV will be
* returned.
*
* NOTE: it's expected that most callers should _ignore_ the errors returned
* by this function. Other debugfs functions handle the fact that the "dentry"
* passed to them could be an error and they don't crash in that case.
* Drivers should generally work fine even if debugfs fails to init anyway.

Adhere to the debugfs spirit, and streamline all operations by:
1. Demoting the importance of the printed error messages to debug
level, like is already done in create_regulator(),
2. Further ignoring any returned errors, as by design, all debugfs
functions are no-ops when passed an error pointer.

Fixes: 2bf1c45be3b8f3a3 ("regulator: Fix error checking for debugfs_create_dir")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2f8bb6e113359ddfab7b59e4d4274bd4c06d6d0a.1685013051.git.geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix more error checking for debugfs_create_dir()

In case of failure, debugfs_create_dir() does not return NULL, but an
error pointer. Most incorrect error checks were fixed, but the one in
create_regulator() was forgotten.

Fix the remaining error check.

Fixes: 2bf1c45be3b8f3a3 ("regulator: Fix error checking for debugfs_create_dir")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/ee980a108b5854dd8ce3630f8f673e784e057d17.1685013051.git.geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix error checking for debugfs_create_dir

This patch fixes the error checking in core.c in debugfs_create_dir.
The correct way to check if an error occurred is 'IS_ERR' inline function.

Signed-off-by: Osama Muhammad <osmtendev@gmail.com
Suggested-by: Ivan Orlov <ivan.orlov0322@gmail.com
Link: https://lore.kernel.org/r/20230515172938.13338-1-osmtendev@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org

regulator: core: Make regulator_lock_two() logic easier to follow

The regulator_lock_two() function could be made clearer in the case of
lock contention by having a local variable for each of the held and
contended locks. Let's do that. At the same time, let's use the swap()
function instead of open coding it.

This change is expected to be a no-op and simply improves code
clarity.

Suggested-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/CAE-0n53Eb1BeDPmjBycXUaQAF4ppiAM6UDWje_jiB9GAmR8MMw@mail.gmail.com
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230413173359.1.I1ae92b25689bd6579952e6d458b79f5f8054a0c9@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Avoid lockdep reports when resolving supplies

An automated bot told me that there was a potential lockdep problem
with regulators. This was on the chromeos-5.15 kernel, but I see
nothing that would be different downstream compared to upstream. The
bot said:
============================================
WARNING: possible recursive locking detected
5.15.104-lockdep-17461-gc1e499ed6604 #1 Not tainted
--------------------------------------------
kworker/u16:4/115 is trying to acquire lock:
ffffff8083110170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: create_regulator+0x398/0x7ec

but task is already holding lock:
ffffff808378e170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: ww_mutex_trylock+0x3c/0x7b8

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

CPU0
----
lock(regulator_ww_class_mutex);
lock(regulator_ww_class_mutex);

*** DEADLOCK ***

May be due to missing lock nesting notation

4 locks held by kworker/u16:4/115:
#0: ffffff808006a948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x520/0x1348
#1: ffffffc00e0a7cc0 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x55c/0x1348
#2: ffffff80828a2260 (&dev->mutex){....}-{3:3}, at: __device_attach_async_helper+0xd0/0x2a4
#3: ffffff808378e170 (regulator_ww_class_mutex){+.+.}-{3:3}, at: ww_mutex_trylock+0x3c/0x7b8

stack backtrace:
CPU: 2 PID: 115 Comm: kworker/u16:4 Not tainted 5.15.104-lockdep-17461-gc1e499ed6604 #1 9292e52fa83c0e23762b2b3aa1bacf5787a4d5da
Hardware name: Google Quackingstick (rev0+) (DT)
Workqueue: events_unbound async_run_entry_fn
Call trace:
dump_backtrace+0x0/0x4ec
show_stack+0x34/0x50
dump_stack_lvl+0xdc/0x11c
dump_stack+0x1c/0x48
__lock_acquire+0x16d4/0x6c74
lock_acquire+0x208/0x750
__mutex_lock_common+0x11c/0x11f8
ww_mutex_lock+0xc0/0x440
create_regulator+0x398/0x7ec
regulator_resolve_supply+0x654/0x7c4
regulator_register_resolve_supply+0x30/0x120
class_for_each_device+0x1b8/0x230
regulator_register+0x17a4/0x1f40
devm_regulator_register+0x60/0xd0
reg_fixed_voltage_probe+0x728/0xaec
platform_probe+0x150/0x1c8
really_probe+0x274/0xa20
__driver_probe_device+0x1dc/0x3f4
driver_probe_device+0x78/0x1c0
__device_attach_driver+0x1ac/0x2c8
bus_for_each_drv+0x11c/0x190
__device_attach_async_helper+0x1e4/0x2a4
async_run_entry_fn+0xa0/0x3ac
process_one_work+0x638/0x1348
worker_thread+0x4a8/0x9c4
kthread+0x2e4/0x3a0
ret_from_fork+0x10/0x20

The problem was first reported soon after we made many of the
regulators probe asynchronously, though nothing I've seen implies that
the problems couldn't have also happened even without that.

I haven't personally been able to reproduce the lockdep issue, but the
issue does look somewhat legitimate. Specifically, it looks like in
regulator_resolve_supply() we are holding a "rdev" lock while calling
set_supply() -> create_regulator() which grabs the lock of a
_different_ "rdev" (the one for our supply). This is not necessarily
safe from a lockdep perspective since there is no documented ordering
between these two locks.

In reality, we should always be locking a regulator before the
supplying regulator, so I don't expect there to be any real deadlocks
in practice. However, the regulator framework in general doesn't
express this to lockdep.

Let's fix the issue by simply grabbing the two locks involved in the
same way we grab multiple locks elsewhere in the regulator framework:
using the "wound/wait" mechanisms.

Fixes: eaa7995c529b ("regulator: core: avoid regulator_resolve_supply() race condition")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230329143317.RFC.v2.2.I30d8e1ca10cfbe5403884cdd192253a2e063eb9e@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Consistently set mutex_owner when using ww_mutex_lock_slow()

When a codepath locks a rdev using ww_mutex_lock_slow() directly then
that codepath is responsible for incrementing the "ref_cnt" and also
setting the "mutex_owner" to "current".

The regulator core consistently got that right for "ref_cnt" but
didn't always get it right for "mutex_owner". Let's fix this.

It's unlikely that this truly matters because the "mutex_owner" is
only needed if we're going to do subsequent locking of the same
rdev. However, even though it's not truly needed it seems less
surprising if we consistently set "mutex_owner" properly.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230329143317.RFC.v2.1.I4e9d433ea26360c06dd1381d091c82bb1a4ce843@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Shorten off-on-delay-us for always-on/boot-on by time since booted

This is very close to a straight revert of commit 218320fec294
("regulator: core: Fix off-on-delay-us for always-on/boot-on
regulators"). We've identified that patch as causing a boot speed
regression on sc7180-trogdor boards. While boot speed certainly isn't
more important than making sure that power sequencing is correct,
looking closely at the original change it doesn't seem to have been
fully justified. It mentions "cycling issues" without describing
exactly what the issues were. That means it's possible that the
cycling issues were really a problem that should be fixed in a
different way.

Let's take a careful look at how we should handle regulators that have
an off-on-delay and that are boot-on or always-on. Linux currently
doesn't have any way to identify whether a GPIO regulator was already
on when the kernel booted. That means that when the kernel boots we
probe a regulator, see that it wants boot-on / always-on we, and then
turn the regulator on. We could be in one of two cases when we do
this:

a) The regulator might have been left on by the bootloader and we're
ensuring that it stays on.
b) The regulator might have been left off by the bootloader and we're
just now turning it on.

For case a) we definitely don't need any sort of delay. For case b) we
_might_ need some delay in case the bootloader turned the regulator
off _right_ before booting the kernel. To get the proper delay for
case b) then we can just assume a `last_off` of 0, which is what it
gets initialized to by default.

As per above, we can't tell whether we're in case a) or case b) so
we'll assume the longer delay (case b). This basically puts the code
to how it was before commit 218320fec294 ("regulator: core: Fix
off-on-delay-us for always-on/boot-on regulators"). However, we add
one important change: we make sure that the delay is actually honored
if `last_off` is 0. Though the original "cycling issues" cited were
vague, I'm hopeful that this important extra change will be enough to
fix the issues that the initial commit mentioned.

With this fix, I've confined that on a sc7180-trogdor board the delay
at boot goes down from 500 ms to ~250 ms. That's not as good as the 0
ms that we had prior to commit 218320fec294 ("regulator: core: Fix
off-on-delay-us for always-on/boot-on regulators"), but it's probably
safer because we don't know if the bootloader turned the regulator off
right before booting.

One note is that it's possible that we could be in a state that's not
a) or b) if there are other issues in the kernel. The only one I can
think of is related to pinctrl. If the pinctrl driver being used on a
board isn't careful about avoiding glitches when setting up a pin then
it's possible that setting up a pin could cause the regulator to "turn
off" briefly immediately before the regulator probes. If this is
indeed causing problems then the pinctrl driver should be fixed,
perhaps in a similar way to what was done in commit d21f4b7ffc22
("pinctrl: qcom: Avoid glitching lines when we first mux to output")

Fixes: 218320fec294 ("regulator: core: Fix off-on-delay-us for always-on/boot-on regulators")
Cc: Christian Kohlschütter <christian@kohlschutter.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20230313111806.1.I2eaad872be0932a805c239a7c7a102233fb0b03b@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use ktime_get_boottime() to determine how long a regulator was off

For regulators with 'off-on-delay-us' the regulator framework currently
uses ktime_get() to determine how long the regulator has been off
before re-enabling it (after a delay if needed). A problem with using
ktime_get() is that it doesn't account for the time the system is
suspended. As a result a regulator with a longer 'off-on-delay' (e.g.
500ms) that was switched off during suspend might still incurr in a
delay on resume before it is re-enabled, even though the regulator
might have been off for hours. ktime_get_boottime() accounts for
suspend time, use it instead of ktime_get().

Fixes: a8ce7bd89689 ("regulator: core: Fix off_on_delay handling")
Cc: stable@vger.kernel.org # 5.13+
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230223003301.v2.1.I9719661b8eb0a73b8c416f9c26cf5bd8c0563f99@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix deadlock on regulator enable

When updating the operating mode as part of regulator enable, the caller
has already locked the regulator tree and drms_uA_update() must not try
to do the same in order not to trigger a deadlock.

The lock inversion is reported by lockdep as:

======================================================
WARNING: possible circular locking dependency detected
6.1.0-next-20221215 #142 Not tainted
------------------------------------------------------
udevd/154 is trying to acquire lock:
ffffc11f123d7e50 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x280

but task is already holding lock:
ffff80000e4c36e8 (regulator_ww_class_acquire){+.+.}-{0:0}, at: regulator_enable+0x34/0x80

which lock already depends on the new lock.

...

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(regulator_ww_class_acquire);
lock(regulator_list_mutex);
lock(regulator_ww_class_acquire);
lock(regulator_list_mutex);

*** DEADLOCK ***

just before probe of a Qualcomm UFS controller (occasionally) deadlocks
when enabling one of its regulators.

Fixes: 9243a195be7a ("regulator: core: Change voltage setting path")
Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221215104646.19818-1-johan+linaro@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix resolve supply lookup issue

From Marek's log, the previous change modify the parent of rdev.
https://lore.kernel.org/all/58b92e75-f373-dae7-7031-8abd465bb874@samsung.com/

In 'regulator_resolve_supply', it uses the parent DT node of rdev as the
DT-lookup starting node. But the parent DT node may not exist. This will
cause the NULL supply issue.

This patch modify the parent of rdev back to the device that provides
from 'regulator_config' in 'regulator_register'.

Fixes: 8f3cbcd6b440 ("regulator: core: Use different devices for resource allocation and DT lookup")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/1670981831-12583-1-git-send-email-u0084500@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use different devices for resource allocation and DT lookup

Following by the below discussion, there's the potential UAF issue
between regulator and mfd.
https://lore.kernel.org/all/20221128143601.1698148-1-yangyingliang@huawei.com/

From the analysis of Yingliang

CPU A |CPU B
mt6370_probe() |
devm_mfd_add_devices() |
|mt6370_regulator_probe()
| regulator_register()
| //allocate init_data and add it to devres
| regulator_of_get_init_data()
i2c_unregister_device() |
device_del() |
devres_release_all() |
// init_data is freed |
release_nodes() |
| // using init_data causes UAF
| regulator_register()

It's common to use mfd core to create child device for the regulator.
In order to do the DT lookup for init data, the child that registered
the regulator would pass its parent as the parameter. And this causes
init data resource allocated to its parent, not itself. The issue happen
when parent device is going to release and regulator core is still doing
some operation of init data constraint for the regulator of child device.

To fix it, this patch expand 'regulator_register' API to use the
different devices for init data allocation and DT lookup.

Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Link: https://lore.kernel.org/r/1670311341-32664-1-git-send-email-u0084500@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix resource leak in regulator_register()

I got some resource leak reports while doing fault injection test:

OF: ERROR: memory leak, expected refcount 1 instead of 100,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /i2c/pmic@64/regulators/buck1

unreferenced object 0xffff88810deea000 (size 512):
comm "490-i2c-rt5190a", pid 253, jiffies 4294859840 (age 5061.046s)
hex dump (first 32 bytes):
00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N..........
ff ff ff ff ff ff ff ff a0 1e 00 a1 ff ff ff ff ................
backtrace:
[<00000000d78541e2>] kmalloc_trace+0x21/0x110
[<00000000b343d153>] device_private_init+0x32/0xd0
[<00000000be1f0c70>] device_add+0xb2d/0x1030
[<00000000e3e6344d>] regulator_register+0xaf2/0x12a0
[<00000000e2f5e754>] devm_regulator_register+0x57/0xb0
[<000000008b898197>] rt5190a_probe+0x52a/0x861 [rt5190a_regulator]

unreferenced object 0xffff88810b617b80 (size 32):
comm "490-i2c-rt5190a", pid 253, jiffies 4294859904 (age 5060.983s)
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2e 32 38 36 38 2d 53 regulator.2868-S
55 50 50 4c 59 00 ff ff 29 00 00 00 2b 00 00 00 UPPLY...)...+...
backtrace:
[<000000009da9280d>] __kmalloc_node_track_caller+0x44/0x1b0
[<0000000025c6a4e5>] kstrdup+0x3a/0x70
[<00000000790efb69>] create_regulator+0xc0/0x4e0
[<0000000005ed203a>] regulator_resolve_supply+0x2d4/0x440
[<0000000045796214>] regulator_register+0x10b3/0x12a0
[<00000000e2f5e754>] devm_regulator_register+0x57/0xb0
[<000000008b898197>] rt5190a_probe+0x52a/0x861 [rt5190a_regulator]

After calling regulator_resolve_supply(), the 'rdev->supply' is set
by set_supply(), after this set, in the error path, the resources
need be released, so call regulator_put() to avoid the leaks.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Fixes: 8a866d527ac0 ("regulator: core: Resolve supply name earlier to prevent double-init")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221202025111.496402-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix module refcount leak in set_supply()

If create_regulator() fails in set_supply(), the module refcount
needs be put to keep refcount balanced.

Fixes: e2c09ae7a74d ("regulator: core: Increase refcount for regulator supply's module")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221201122706.4055992-2-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix use_count leakage when handling boot-on

I found a use_count leakage towards supply regulator of rdev with
boot-on option.

┌───────────────────┐ ┌───────────────────┐
│ regulator_dev A │ │ regulator_dev B │
│ (boot-on) │ │ (boot-on) │
│ use_count=0 │◀──supply──│ use_count=1 │
│ │ │ │
└───────────────────┘ └───────────────────┘

In case of rdev(A) configured with `regulator-boot-on', the use_count
of supplying regulator(B) will increment inside
regulator_enable(rdev->supply).

Thus, B will acts like always-on, and further balanced
regulator_enable/disable cannot actually disable it anymore.

However, B was also configured with `regulator-boot-on', we wish it
could be disabled afterwards.

Signed-off-by: Rui Zhang <zr.zhang@vivo.com>
Link: https://lore.kernel.org/r/20221201033806.2567812-1-zr.zhang@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: use kfree_const() to free space conditionally

Use kfree_const() to free supply_name conditionally in create_regulator()
as supply_name may be allocated from kmalloc() or directly from .rodata
section.

Fixes: 87fe29b61f95 ("regulator: push allocations in create_regulator() outside of lock")
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Link: https://lore.kernel.org/r/20221123034616.3609537-1-bobo.shaobowang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix unbalanced of node refcount in regulator_dev_lookup()

I got the the following report:

OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /i2c/pmic@62/regulators/exten

In of_get_regulator(), the node is returned from of_parse_phandle()
with refcount incremented, after using it, of_node_put() need be called.

Fixes: 69511a452e6d ("regulator: map consumer regulator based on device tree")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221115091508.900752-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: devres: Add devm_regulator_bulk_get_exclusive()

We had an exclusive variant of the devm_regulator_get() API, but no
corresponding variant for the bulk API; let's add one now. We add a
generalized version of the existing regulator_bulk_get() function that
additionally takes a get_type parameter and redefine
regulator_bulk_get() in terms of it, then do similarly with
devm_regulator_bulk_get(), and finally add the new
devm_regulator_bulk_get_exclusive().

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20221031233704.22575-2-zev@bewilderbeest.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix UAF in destroy_regulator()

I got a UAF report as following:

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x935/0x2060
Read of size 8 at addr ffff88810e838220 by task python3/268
Call Trace:
<TASK>
dump_stack_lvl+0x67/0x83
print_report+0x178/0x4b0
kasan_report+0x90/0x190
__lock_acquire+0x935/0x2060
lock_acquire+0x156/0x400
_raw_spin_lock+0x2a/0x40
lockref_get+0x11/0x30
simple_recursive_removal+0x41/0x440
debugfs_remove.part.12+0x32/0x50
debugfs_remove+0x29/0x30
_regulator_put.cold.54+0x3e/0x27f
regulator_put+0x1f/0x30
release_nodes+0x6a/0xa0
devres_release_all+0xf8/0x150

Allocated by task 37:
kasan_save_stack+0x1c/0x40
kasan_set_track+0x21/0x30
__kasan_slab_alloc+0x5d/0x70
slab_post_alloc_hook+0x62/0x510
kmem_cache_alloc_lru+0x222/0x5a0
__d_alloc+0x31/0x440
d_alloc+0x30/0xf0
d_alloc_parallel+0xc4/0xd20
__lookup_slow+0x15e/0x2f0
lookup_one_len+0x13a/0x150
start_creating+0xea/0x190
debugfs_create_dir+0x1e/0x210
create_regulator+0x254/0x4e0
_regulator_get+0x2a1/0x467
_devm_regulator_get+0x5a/0xb0
regulator_virtual_probe+0xb9/0x1a0

Freed by task 30:
kasan_save_stack+0x1c/0x40
kasan_set_track+0x21/0x30
kasan_save_free_info+0x2a/0x50
__kasan_slab_free+0x102/0x190
kmem_cache_free+0xf6/0x600
rcu_core+0x54c/0x12b0
__do_softirq+0xf2/0x5e3

Last potentially related work creation:
kasan_save_stack+0x1c/0x40
__kasan_record_aux_stack+0x98/0xb0
call_rcu+0x42/0x700
dentry_free+0x6c/0xd0
__dentry_kill+0x23b/0x2d0
dput.part.31+0x431/0x780
simple_recursive_removal+0xa9/0x440
debugfs_remove.part.12+0x32/0x50
debugfs_remove+0x29/0x30
regulator_unregister+0xe3/0x230
release_nodes+0x6a/0xa0

==================================================================

Here is how happened:

processor A processor B
regulator_register()
rdev_init_debugfs()
rdev->debugfs = debugfs_create_dir()
devm_regulator_get()
rdev = regulator_dev_lookup()
create_regulator(rdev)
// using rdev->debugfs as parent
debugfs_create_dir(rdev->debugfs)

mfd_remove_devices_fn()
release_nodes()
regulator_unregister()
// free rdev->debugfs
debugfs_remove_recursive(rdev->debugfs)
release_nodes()
destroy_regulator()
debugfs_remove_recursive() <- causes UAF

In devm_regulator_get(), after getting rdev, the refcount
is get, so fix this by moving debugfs_remove_recursive()
to regulator_dev_release(), then it can be proctected by
the refcount, the 'rdev->debugfs' can not be freed until
the refcount is 0.

Fixes: 5de705194e98 ("regulator: Add basic per consumer debugfs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221116033706.3595812-1-yangyingliang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix kobject release warning and memory leak in regulator_register()

Here is a warning report about lack of registered release()
from kobject lib:

Device '(null)' does not have a release() function, it is broken and must be fixed.
WARNING: CPU: 0 PID: 48430 at drivers/base/core.c:2332 device_release+0x104/0x120
Call Trace:
kobject_put+0xdc/0x180
put_device+0x1b/0x30
regulator_register+0x651/0x1170
devm_regulator_register+0x4f/0xb0

When regulator_register() returns fail and directly goto `clean` symbol,
rdev->dev has not registered release() function yet (which is registered
by regulator_class in the following), so rdev needs to be freed manually.
If rdev->dev.of_node is not NULL, which means the of_node has gotten by
regulator_of_get_init_data(), it needs to call of_node_put() to avoid
refcount leak.

Otherwise, only calling put_device() would lead memory leak of rdev
in further:

unreferenced object 0xffff88810d0b1000 (size 2048):
comm "107-i2c-rtq6752", pid 48430, jiffies 4342258431 (age 1341.780s)
backtrace:
kmalloc_trace+0x22/0x110
regulator_register+0x184/0x1170
devm_regulator_register+0x4f/0xb0

When regulator_register() returns fail and goto `wash` symbol,
rdev->dev has registered release() function, so directly call
put_device() to cleanup everything.

Fixes: d3c731564e09 ("regulator: plug of_node leak in regulator_register()'s error path")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Link: https://lore.kernel.org/r/20221116074339.1024240-1-zengheng4@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Prevent integer underflow

By using a ratio of delay to poll_enabled_time that is not integer
time_remaining underflows and does not exit the loop as expected.
As delay could be derived from DT and poll_enabled_time is defined
in the driver this can easily happen.

Use a signed iterator to make sure that the loop exits once
the remaining time is negative.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Link: https://lore.kernel.org/r/20220909125954.577669-1-patrick.rudolph@9elements.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix regulator supply registration with sysfs

In "regulator: core: Resolve supply name earlier to prevent
double-init", we introduced a bug that prevented the regulator names
from registering properly with sysfs.

Reorder regulator_register such that supply names are properly resolved
and registered.

Fixes: 8a866d527ac0 ("regulator: core: Resolve supply name earlier to prevent double-init")
Link: https://lore.kernel.org/all/58b92e75-f373-dae7-7031-8abd465bb874@samsung.com/
Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20220829165543.24856-1-christian@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't err if allow-set-load but no allowed-modes

Apparently the device trees of some boards have the property
"regulator-allow-set-load" for some of their regulators but then they
don't specify anything for "regulator-allowed-modes". That's not
really legit, but...

...before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement
get_optimum_mode(), not set_load()") they used to get away with it, at
least on boards using RPMH regulators. That's because when a regulator
driver implements set_load() then the core doesn't look at
"regulator-allowed-modes" when trying to automatically adjust things
in response to the regulator's load. The core doesn't know what mode
we'll end up in, so how could it validate it?

Said another way: before commit efb0cb50c427 ("regulator: qcom-rpmh:
Implement get_optimum_mode(), not set_load()") some boards _were_
having the regulator mode adjusted despite listing no allowed
modes. After commit efb0cb50c427 ("regulator: qcom-rpmh: Implement
get_optimum_mode(), not set_load()") these same boards were now
getting an error returned when trying to use their regulators, since
simply enabling a regulator tries to update its load and that was
failing.

We don't really want to go back to the behavior from before commit
efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not
set_load()"). Boards shouldn't have been changing modes if no allowed
modes were listed. However, the behavior after commit efb0cb50c427
("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()")
isn't the best because now boards can't even turn their regulators on.

Let's choose to detect this case and return "no error" from
drms_uA_update(). The net-result will be _different_ behavior than we
had before commit efb0cb50c427 ("regulator: qcom-rpmh: Implement
get_optimum_mode(), not set_load()"), but this new behavior seems more
correct. If a board truly needed the mode switched then its device
tree should be updated to list the allowed modes.

Reported-by: Andrew Halaney <ahalaney@redhat.com>
Fixes: efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/20220824142229.RFT.v2.2.I6f77860e5cd98bf5c67208fa9edda4a08847c304@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Require regulator drivers to check uV for get_optimum_mode()

The get_optimum_mode() for regulator drivers is passed the input
voltage and output voltage as well as the current. This is because, in
theory, the optimum mode can depend on all three things.

It turns out that for all regulator drivers in mainline only the
current is looked at when implementing get_optimum_mode(). None of the
drivers take the input or output voltage into account. Despite the
fact that none of the drivers take the input or output voltage into
account, though, the regulator framework will error out before calling
into get_optimum_mode() if it doesn't know the input or output
voltage.

The above behavior turned out to be a probelm for some boards when we
landed commit efb0cb50c427 ("regulator: qcom-rpmh: Implement
get_optimum_mode(), not set_load()"). Before that change we'd have no
problems running drms_uA_update() for RPMH regulators even if a
regulator's input or output voltage was unknown. After that change
drms_uA_update() started to fail. This is because typically boards
using RPMH regulators don't model the input supplies of RPMH
regulators. Input supplies for RPMH regulators nearly always come from
the output of other RPMH regulators (or always-on regulators) and RPMH
firmware is initialized with this knowledge and handles enabling (and
adjusting the voltage of) input supplies. While we could model the
parent/child relationship of the regulators in Linux, many boards
don't bother since it adds extra overhead.

Let's change the regulator core to make things work again. Now if we
fail to get the input or output voltage we'll still call into
get_optimum_mode() and we'll just pass error codes in for input_uV
and/or output_uV parameters.

Since no existing regulator drivers even look at input_uV and
output_uV we don't need to add this error handling anywhere right
now. We'll add some comments in the core so that it's obvious that (if
regulator drivers care) it's up to them to add the checks.

Reported-by: Andrew Halaney <ahalaney@redhat.com>
Fixes: efb0cb50c427 ("regulator: qcom-rpmh: Implement get_optimum_mode(), not set_load()")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Link: https://lore.kernel.org/r/20220824142229.RFT.v2.1.I137e6bef4f6d517be7b081be926059321102fd3d@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Remove "ramp_delay not set" debug message

This message shows up occasionally but in bursts (seen up to 30 times
per second on my ODROID N2+).

According to Matthias Kaehlcke's comment in 'regulator: core: silence
warning: "VDD1: ramp_delay not set"', this message should have been
removed after restructuring previous code that assumed that ramp_delay
being zero in that function was an error.

Link: https://lore.kernel.org/lkml/625675256c0d75805f088b4be17a3308dc1b7ea4.1477571498.git.hns@goldelico.com/T/
Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Link: https://lore.kernel.org/r/20220820131420.16608-1-christian@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Resolve supply name earlier to prevent double-init

Previously, an unresolved regulator supply reference upon calling
regulator_register on an always-on or boot-on regulator caused
set_machine_constraints to be called twice.

This in turn may initialize the regulator twice, leading to voltage
glitches that are timing-dependent. A simple, unrelated configuration
change may be enough to hide this problem, only to be surfaced by
chance.

One such example is the SD-Card voltage regulator in a NanoPI R4S that
would not initialize reliably unless the registration flow was just
complex enough to allow the regulator to properly reset between calls.

Fix this by re-arranging regulator_register, trying resolve the
regulator's supply early enough that set_machine_constraints does not
need to be called twice.

Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Link: https://lore.kernel.org/r/20220818124646.6005-1-christian@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Clean up on enable failure

If regulator_enable() fails, enable_count is incremented still.
A consumer, assuming no matching regulator_disable() is necessary on
failure, will then get this error message upon regulator_put()
since enable_count is non-zero:

[ 1.277418] WARNING: CPU: 3 PID: 1 at drivers/regulator/core.c:2304 _regulator_put.part.0+0x168/0x170

The consumer could try to fix this in their driver by cleaning up on
error from regulator_enable() (i.e. call regulator_disable()), but that
results in the following since regulator_enable() failed and didn't
increment user_count:

[ 1.258112] unbalanced disables for vreg_l17c
[ 1.262606] WARNING: CPU: 4 PID: 1 at drivers/regulator/core.c:2899 _regulator_disable+0xd4/0x190

Fix this by decrementing enable_count upon failure to enable.

With this in place, just the reason for failure to enable is printed
as expected and developers can focus on the root cause of their issue
instead of thinking their usage of the regulator consumer api is
incorrect. For example, in my case:

[ 1.240426] vreg_l17c: invalid input voltage found

Fixes: 5451781dadf8 ("regulator: core: Only count load for enabled consumers")
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20220819194336.382740-1-ahalaney@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix missing error return from regulator_bulk_get()

In commit 6eabfc018e8d ("regulator: core: Allow specifying an initial
load w/ the bulk API") I changed the error handling but had a subtle
that caused us to always return no error even if there was an
error. Fix it.

Fixes: 6eabfc018e8d ("regulator: core: Allow specifying an initial load w/ the bulk API")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20220809142738.1.I91625242f137c707bb345c51c80c5ecee02eeff3@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Allow specifying an initial load w/ the bulk API

There are a number of drivers that follow a pattern that looks like
this:
1. Use the regulator bulk API to get a bunch of regulators.
2. Set the load on each of the regulators to use whenever the
regulators are enabled.

Let's make this easier by just allowing the drivers to pass the load
in.

As part of this change we need to move the error printing in
regulator_bulk_get() around; let's switch to the new dev_err_probe()
to simplify it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20220726103631.v2.4.Ie85f68215ada39f502a96dcb8a1f3ad977e3f68a@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix off-on-delay-us for always-on/boot-on regulators

Regulators marked with "regulator-always-on" or "regulator-boot-on"
as well as an "off-on-delay-us", may run into cycling issues that are
hard to detect.

This is caused by the "last_off" state not being initialized in this
case.

Fix the "last_off" initialization by setting it to the current kernel
time upon initialization, regardless of always_on/boot_on state.

Signed-off-by: Christian Kohlschütter <christian@kohlschutter.com>
Link: https://lore.kernel.org/r/FAFD5B39-E9C4-47C7-ACF1-2A04CD59758D@kohlschutter.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix enable_count imbalance with EXCLUSIVE_GET

Since the introduction of regulator->enable_count, a driver that did
an exclusive get on an already-enabled regulator would end up with
enable_count initialized to 0 but rdev->use_count initialized to 1.
With that starting point the regulator is effectively stuck enabled,
because if the driver attempted to disable it it would fail the
enable_count underflow check in _regulator_handle_consumer_disable().

The EXCLUSIVE_GET path in _regulator_get() now initializes
enable_count along with rdev->use_count so that the regulator can be
disabled without underflowing the former.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Fixes: 5451781dadf85 ("regulator: core: Only count load for enabled consumers")
Link: https://lore.kernel.org/r/20220505043152.12933-1-zev@bewilderbeest.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add error flags to sysfs attributes

If a regulator provides a get_error_flags() operation, its sysfs
attributes will now include an entry for each defined
REGULATOR_ERROR_* flag.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20220504065252.6955-3-zev@bewilderbeest.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Sleep (not delay) in set_voltage()

These delays can be relatively large (e.g., hundreds of microseconds to
several milliseconds on RK3399 Gru systems). Per
Documentation/timers/timers-howto.rst, that should usually use a
sleeping delay. Let's use the existing regulator delay helper to handle
both large and small delays appropriately. This avoids burning a bunch
of CPU time and hurting scheduling latencies when hitting regulators a
lot (e.g., during cpufreq).

The sleep vs. delay issue choice has been made differently over time --
early versions of RK3399 Gru PWM-regulator support used usleep_range()
in pwm-regulator.c. More of this got moved into the regulator core,
in commits like:

73e705bf81ce regulator: core: Add set_voltage_time op

At the same time, the sleep turned into a delay.

It's OK to sleep in _regulator_do_set_voltage(), as we aren't in an
atomic context. (All our callers grab various mutexes already.)

I avoid using fsleep() because it uses a usleep_range() of [N to N*2],
and usleep_range() very commonly biases to the high end of the range. We
don't want to double the expected delay, especially for long delays.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20220420141511.v2.2.If0fc61a894f537b052ca41572aff098cf8e7e673@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Rename _regulator_enable_delay()

I want to use it in other contexts besides _regulator_do_enable().

Signed-off-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20220420141511.v2.1.I31ef0014c9597d53722ab513890f839f357fdfb3@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Flag uncontrollable regulators as always_on

While we currently assume that regulators with no control available are
just uncontionally enabled this isn't always as clearly displayed to
users as is desirable, for example the code for disabling unused
regulators will log that it is about to disable them. Clean this up a
bit by setting always_on during constraint evaluation if we have no
available mechanism for controlling the regualtor so things that check
the constraint will do the right thing.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220325144637.1543496-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix false positive in regulator_late_cleanup()

The check done by regulator_late_cleanup() to detect whether a regulator
is on was inconsistent with the check done by _regulator_is_enabled().
While _regulator_is_enabled() takes the enable GPIO into account,
regulator_late_cleanup() was not doing that.

This resulted in a false positive, e.g. when a GPIO-controlled fixed
regulator was used, which was not enabled at boot time, e.g.

reg_disp_1v2: reg_disp_1v2 {
compatible = "regulator-fixed";
regulator-name = "display_1v2";
regulator-min-microvolt = <1200000>;
regulator-max-microvolt = <1200000>;
gpio = <&tlmm 148 0>;
enable-active-high;
};

Such regulator doesn't have an is_enabled() operation. Nevertheless
it's state can be determined based on the enable GPIO. The check in
regulator_late_cleanup() wrongly assumed that the regulator is on and
tried to disable it.

Signed-off-by: Oliver Barta <oliver.barta@aptiv.com>
Link: https://lore.kernel.org/r/20220208084645.8686-1-oliver.barta@aptiv.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Don't error out fixed regulator in regulator_sync_voltage()

Fixed regulator can't change voltage and regulator_sync_voltage()
returns -EINVAL in this case. Make regulator_sync_voltage() to succeed
for regulators that are incapable to change voltage.

On NVIDIA Tegra power management driver needs to sync voltage and we have
one device (Trimslice) that uses fixed regulator which is getting synced.
The syncing error isn't treated as fatal, but produces a noisy error
message. This patch silences that error.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20211021183308.27786-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Lower priority of logging when setting supply

We lowered all the other constraint related log messages to debug level so
lower the logging of what supplies we're configuring to debug level too.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210929140717.3769-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

kernel/locking: Add context to ww_mutex_trylock()

i915 will soon gain an eviction path that trylock a whole lot of locks
for eviction, getting dmesg failures like below:

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by i915_selftest/5776:
#0: ffff888101a79240 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x88/0x160
#1: ffffc900009778c0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.63+0x39/0x1b0 [i915]
#2: ffff88800cf74de8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.63+0x5f/0x1b0 [i915]
#3: ffff88810c7f9e38 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x1c4/0x9d0 [i915]
#4: ffff88810bad5768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
#5: ffff88810bad60e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
...
#46: ffff88811964d768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
#47: ffff88811964e0e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915]
INFO: lockdep is turned off.

Fixing eviction to nest into ww_class_acquire is a high priority, but
it requires a rework of the entire driver, which can only be done one
step at a time.

As an intermediate solution, add an acquire context to
ww_mutex_trylock, which allows us to do proper nesting annotations on
the trylocks, making the above lockdep splat disappear.

This is also useful in regulator_lock_nested, which may avoid dropping
regulator_nesting_mutex in the uncontended path, so use it there.

TTM may be another user for this, where we could lock a buffer in a
fastpath with list locks held, without dropping all locks we hold.

[peterz: rework actual ww_mutex_trylock() implementations]
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YUBGPdDDjKlxAuXJ@hirez.programming.kicks-ass.net

regulator: core: resolve supply voltage deferral silently

Voltage-controlled regulators depend on their supply regulator for
retrieving their voltage, and so they might return -EPROBE_DEFER at this
stage. Our caller already attempts to resolve supplies and retry, so we
shouldn't be printing this error to logs.

Quiets log messages like this, on Rockchip RK3399 Gru/Kevin boards:

[ 1.033057] ppvar_bigcpu: failed to get the current voltage: -EPROBE_DEFER
...
[ 1.036735] ppvar_litcpu: failed to get the current voltage: -EPROBE_DEFER
...
[ 1.040366] ppvar_gpu: failed to get the current voltage: -EPROBE_DEFER
...
[ 1.044086] ppvar_centerlogic: failed to get the current voltage: -EPROBE_DEFER

Cc: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20210826124015.1.Iab79c6dd374ec48beac44be2fcddd165dd26476b@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: add property parsing and callbacks to set protection limits

Add DT property parsing code and setting callback for regulator over/under
voltage, over-current and temperature error limits.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/e7b8007ba9eae7076178bf3363fb942ccb1cc9a5.1622628334.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: IRQ based event/error notification helpers

Provide helper function for IC's implementing regulator notifications
when an IRQ fires. The helper also works for IRQs which can not be acked.
Helper can be set to disable the IRQ at handler and then re-enabling it
on delayed work later. The helper also adds regulator_get_error_flags()
errors in cache for the duration of IRQ disabling.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/ebdf86d8c22b924667ec2385330e30fcbfac0119.1622628334.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: move rdev_print helpers to internal.h

The rdev print helpers are a nice way to print messages related to a
specific regulator device. Move them from core.c to internal.h

As the rdev print helpers use rdev_get_name() export it from core.c. Also
move the declaration from coupler.h to driver.h because the rdev name is
not just a coupled regulator property. I guess the main audience for
rdev_get_name() will be the regulator core and drivers.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/dc7fd70dc31de4d0e820b7646bb78eeb04f80735.1622628333.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use DEVICE_ATTR_RO macro

Use DEVICE_ATTR_RO() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20210529115226.25376-1-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add regulator_sync_voltage_rdev()

Some NVIDIA Tegra devices use a CPU soft-reset method for the reboot and
in this case we need to restore the coupled voltages to the state that is
suitable for hardware during boot. Add new regulator_sync_voltage_rdev()
helper which is needed by regulator drivers in order to sync voltage of
a coupled regulators.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

regulator: core: resolve supply for boot-on/always-on regulators

For the boot-on/always-on regulators the set_machine_constrainst() is
called before resolving rdev->supply. Thus the code would try to enable
rdev before enabling supplying regulator. Enforce resolving supply
regulator before enabling rdev.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210519221224.2868496-1-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix off_on_delay handling

The jiffies-based off_on_delay implementation has a couple of problems
that cause it to sometimes not actually delay for the required time:

(1) If, for example, the off_on_delay time is equivalent to one jiffy,
and the ->last_off_jiffy is set just before a new jiffy starts,
then _regulator_do_enable() does not wait at all since it checks
using time_before().

(2) When jiffies overflows, the value of "remaining" becomes higher
than "max_delay" and the code simply proceeds without waiting.

Fix these problems by changing it to use ktime_t instead.

[Note that since jiffies doesn't start at zero but at INITIAL_JIFFIES
("-5 minutes"), (2) above also led to the code not delaying if
the first regulator_enable() is called when the ->last_off_jiffy is not
initialised, such as for regulators with ->constraints->boot_on set.
It's not clear to me if this was intended or not, but I've preserved
this behaviour explicitly with the check for a non-zero ->last_off.]

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20210423114524.26414-1-vincent.whitchurch@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Respect off_on_delay at startup

We currently do not respect off_on_delay the first time we turn on a
regulator. This is problematic since the regulator could have been
turned off by the bootloader, or it could it have been turned off during
the probe of the regulator driver (such as when regulator-fixed requests
the enable GPIO), either of which could potentially have happened less
than off_on_delay microseconds ago before the first time a client
requests for the regulator to be turned on.

We can't know exactly when the regulator was turned off, but initialise
off_on_delay to the current time when registering the regulator, so that
we guarantee that we respect the off_on_delay in all cases.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20210422083044.11479-1-vincent.whitchurch@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core.c: Improve a comment

s/regulator may on/regulator may already be enabled/
s/or left on/or was left on/

The aim of this patch is to make the comment more readable and to make
it clear, that this is about a regulator, that is already enabled instead
of a regulator that may be switched on.

Signed-off-by: Sebastian Fricke <sebastian.fricke@posteo.net>
Link: https://lore.kernel.org/r/20210421055236.13148-1-sebastian.fricke@posteo.net
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core.c: Fix indentation of comment

Shifted the closing */ of multiline comment to a new line
This is done to maintain code uniformity

Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Link: https://lore.kernel.org/r/20210420034718.t7wudu6xcfpahflv@kewl-virtual-machine
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Avoid debugfs: Directory ... already present! error

Sometimes regulator_get() gets called twice for the same supply on the
same device. This may happen e.g. when a framework / library is used
which uses the regulator; and the driver itself also needs to enable
the regulator in some cases where the framework will not enable it.

Commit ff268b56ce8c ("regulator: core: Don't spew backtraces on
duplicate sysfs") already takes care of the backtrace which would
trigger when creating a duplicate consumer symlink under
/sys/class/regulator/regulator.%d in this scenario.

Commit c33d442328f5 ("debugfs: make error message a bit more verbose")
causes a new error to get logged in this scenario:

[ 26.938425] debugfs: Directory 'wm5102-codec-MICVDD' with parent 'spi-WM510204:00-MICVDD' already present!

There is no _nowarn variant of debugfs_create_dir(), but we can detect
and avoid this problem by checking the return value of the earlier
sysfs_create_link_nowarn() call.

Add a check for the earlier sysfs_create_link_nowarn() failing with
-EEXIST and skip the debugfs_create_dir() call in that case, avoiding
this error getting logged.

Fixes: c33d442328f5 ("debugfs: make error message a bit more verbose")
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20210122183250.370571-1-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Make regulator_sync_voltage() usable by coupled regulators

Make regulator_sync_voltage() to re-balance voltage state of a coupled
regulators instead of changing the voltage directly.

Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Tested-by: Dmitry Osipenko <digetx@gmail.com> # A500 T20 and Nexus7 T30
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210122174311.28230-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core.c: Replace references to non-existent function

The function regulator_set_device_supply() is referenced a few times in
comments in regulator/core.c; however this function was removed a long
time ago by commit a5766f11cfd3 ("regulator: core - Rework machine API to
remove string based functions."). Update those references to point to
set_consumer_device_supply(), which replaced the old function.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Link: https://lore.kernel.org/r/20210103165541.784360-1-djrscally@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix lockdep warning resolving supplies

With commit eaa7995c529b54 (regulator: core: avoid
regulator_resolve_supply() race condition) we started holding the rdev
lock while resolving supplies, an operation that requires holding the
regulator_list_mutex. This results in lockdep warnings since in other
places we take the list mutex then the mutex on an individual rdev.

Since the goal is to make sure that we don't call set_supply() twice
rather than a concern about the cost of resolution pull the rdev lock
and check for duplicate resolution down to immediately before we do the
set_supply() and drop it again once the allocation is done.

Fixes: eaa7995c529b54 (regulator: core: avoid regulator_resolve_supply() race condition)
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210122132042.10306-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: avoid regulator_resolve_supply() race condition

The final step in regulator_register() is to call
regulator_resolve_supply() for each registered regulator
(including the one in the process of being registered). The
regulator_resolve_supply() function first checks if rdev->supply
is NULL, then it performs various steps to try to find the supply.
If successful, rdev->supply is set inside of set_supply().

This procedure can encounter a race condition if two concurrent
tasks call regulator_register() near to each other on separate CPUs
and one of the regulators has rdev->supply_name specified. There
is currently nothing guaranteeing atomicity between the rdev->supply
check and set steps. Thus, both tasks can observe rdev->supply==NULL
in their regulator_resolve_supply() calls. This then results in
both creating a struct regulator for the supply. One ends up
actually stored in rdev->supply and the other is lost (though still
present in the supply's consumer_list).

Here is a kernel log snippet showing the issue:

[ 12.421768] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.425854] gpu_cc_gx_gdsc: supplied by pm8350_s5_level
[ 12.429064] debugfs: Directory 'regulator.4-SUPPLY' with parent
'17a00000.rsc:rpmh-regulator-gfxlvl-pm8350_s5_level'
already present!

Avoid this race condition by holding the rdev->mutex lock inside
of regulator_resolve_supply() while checking and setting
rdev->supply.

Signed-off-by: David Collins <collinsd@codeaurora.org>
Link: https://lore.kernel.org/r/1610068562-4410-1-git-send-email-collinsd@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: return zero for selectors lower than linear_min_sel

Selectors lower than linear_min_sel should not be considered invalid.
Thus return zero in case _regulator_list_voltage(),
regulator_list_hardware_vsel() or regulator_list_voltage_table()
receives such selectors as argument.

Fixes: bdcd1177578c ("regulator: core: validate selector against linear_min_sel")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1606325147-606-1-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: do not continue if selector match

Do not continue if selector has already been located.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1605290164-11556-1-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: validate selector against linear_min_sel

There are regulators who's min selector is not zero. Selectors loops
(looping b/w zero and regulator::desc::n_voltages) might throw errors
because invalid selectors are used (lower than
regulator::desc::linear_min_sel). For this situations validate selectors
against regulator::desc::linear_min_sel.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1605280870-32432-2-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: debug early supply resolving

Help debugging the case when set_machine_constraints() needs to be
repeated.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/f9cba575580369e46661a9278ee6c6a8d8564c2a.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: workaround self-referent regulators

Workaround regulators whose supply name happens to be the same as its
own name. This fixes boards that used to work before the early supply
resolving was removed. The error message is left in place so that
offending drivers can be detected.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/d703acde2a93100c3c7a81059d716c50ad1b1f52.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: avoid resolve_supply() infinite recursion

When a regulator's name equals its supply's name the
regulator_resolve_supply() recurses indefinitely. Add a check
so that debugging the problem is easier. The "fixed" commit
just exposed the problem.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Reported-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/c6171057cfc0896f950c4d8cb82df0f9f1b89ad9.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix memory leak with repeated set_machine_constraints()

Fixed commit introduced a possible second call to
set_machine_constraints() and that allocates memory for
rdev->constraints. Move the allocation to the caller so
it's easier to manage and done once.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # stpmic1
Link: https://lore.kernel.org/r/78c3d4016cebc08d441aad18cb924b4e4d9cf9df.1605226675.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: don't disable regulator if is_enabled return error.

In regulator_late_cleanup when is_enabled failed, don't try to disable
the regulator since it would likely to fail too and causing confusing
error messages.

Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org>
Link: https://lore.kernel.org/r/20201106064817.3290927-1-pihsun@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: defer probe when trying to get voltage from unresolved supply

regulator_get_voltage_rdev() is called in regulator probe() when
applying machine constraints. The "fixed" commit exposed the problem
that non-bypassed regulators can forward the request to its parent
(like bypassed ones) supply. Return -EPROBE_DEFER when the supply
is expected but not resolved yet.

Fixes: aea6cb99703e ("regulator: resolve supply after creating regulator")
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reported-by: Ondřej Jirman <megous@megous.com>
Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Ondřej Jirman <megous@megous.com>
Link: https://lore.kernel.org/r/a9041d68b4d35e4a2dd71629c8a6422662acb5ee.1604351936.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix a kernel-doc markup

It seems that the function was renamed. kernel-doc markup
should follow it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/dffad16d4d6427d7d0fc89797e4126fe7c69d5de.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Make constraint debug processing conditional on DEBUG

If debugging is disabled, print_constraints() does not print the actual
constraints, but still performs some processing and string formatting,
only to throw away the result later.

Fix this by moving all constraint debug processing to a separate
function, and replacing it by a dummy when debugging is disabled.
This reduces kernel size by almost 800 bytes (on arm/arm64).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201005131546.22448-1-geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Enlarge max OF property name length to 64 chars

Some regulator drivers may be defining very long names: this is the
case with the qcom_smd and qcom_spmi regulators, where we need to
parse the regulator parents from DT.

For clarity, this is an example:
{ "l13a", QCOM_SMD_RPM_LDOA, 13, &pm660_ht_lvpldo,
"vdd_l8_l9_l10_l11_l12_l13_l14" },
pm660-regulators {
...
vdd_l8_l9_l10_l11_l12_l13_l14-supply = <&vreg_s4a_2p04>
...
};
Now, with a 32 characters limit, the function is trying to parse,
exactly, "vdd_l8_l9_l10_l11_l12_l13_l14-s" (32 chars) instead of
the right one, which is 37 chars long in this specific case.

... And this is not only the case with PM660/PM660L, but also with
PMA8084, PM8916, PM8950 and others that are not implemented yet.

The length of 64 chars was chosen based on the longest parsed property
name that I could find, which is in PM8916, and would be 53 characters
long.
At that point, rounding that to 64 looked like being the best idea.

Signed-off-by: AngeloGioacchino Del Regno <kholk11@gmail.com>
Link: https://lore.kernel.org/r/20200926125549.13191-2-kholk11@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: resolve supply after creating regulator

When creating a new regulator its supply cannot create the sysfs link
because the device is not yet published. Remove early supply resolving
since it will be done later anyway. This makes the following error
disappear and the symlinks get created instead.

DCDC_REG1: supplied by VSYS
VSYS: could not add device link regulator.3 err -2

Note: It doesn't fix the problem for bypassed regulators, though.

Fixes: 45389c47526d ("regulator: core: Add early supply resolution for regulators")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/ba09e0a8617ffeeb25cb4affffe6f3149319cef8.1601155770.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: print symbolic errors in kernel messages

Change all error-printing messages to include error name via %pe instead
of numeric error or nothing.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/1dcf25f39188882eb56918a9aa281ab17b792aa5.1601155770.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: print state at boot

Make the initial state of the regulator shown when debugging.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/53c4f3d394d68f0989174f89e3b0882cebbbd787.1601155770.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix indentation issue

There is a return statement that is indented with an extra
space, fix this by removing it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200920142454.33352-1-colin.king@canonical.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: unexport regulator_lock/unlock()

regulator_lock/unlock() was used only to guard
regulator_notifier_call_chain(). As no users remain, make the functions
internal.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/d3381aabd2632aff5e7b839d55868bec6e85c811.1600550732.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: don't require mutex for regulator_notifier_call_chain()

Since 3801b86aa482 ("regulator: Refactor supply implementation
to work as regular consumers") we no longer cascade notifications
and so notifier head's built-in rwsem is enough to protect the
notifier chain. Remove the requirement to fix one case where
rdev->mutex might be forced to be taken recursively.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/5a0da9017c69a4dbc3f9b50f44476fce80a73387.1597032945.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix slab-out-of-bounds in regulator_unlock_recursive()

The recent commit 7d8196641ee1 ("regulator: Remove pointer table
overallocation") changed the size of coupled_rdevs and now KASAN is able
to detect slab-out-of-bounds problem in regulator_unlock_recursive(),
which is a legit problem caused by a typo in the code. The recursive
unlock function uses n_coupled value of a parent regulator for unlocking
supply regulator, while supply's n_coupled should be used. In practice
problem may only affect platforms that use coupled regulators.

Cc: stable@vger.kernel.org # 5.0+
Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200831204335.19489-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

regulator: Remove pointer table overallocation

The code allocates sizeof(regulator_dev) for a pointer. Make it less
generous. Let kcalloc() calculate the size, while at it.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/407fbd06a02caf038a9ba3baa51c7d6d47cd6517.1597000795.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Avoid grabbing regulator lock during suspend/resume

I see it takes about 5us per regulator to grab the lock, check that this
regulator isn't going to do anything for suspend, and then release the
lock. When that is combined with PMICs that have dozens of regulators we
get into a state where we spend a few miliseconds doing a bunch of
locking operations synchronously to figure out that there's nothing to
do. Let's reorganize the code here a bit so that we don't grab the lock
until we're actually going to do something so that suspend is a little
faster.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200804070837.1084024-1-swboyd@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: remove superfluous lock in regulator_resolve_coupling()

The code modifies rdev, but locks c_rdev instead. Remove the lock
as this is held together by regulator_list_mutex taken in the caller.

Fixes: f9503385b187 ("regulator: core: Mutually resolve regulators coupling")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/25eb81cefb37a646f3e44eaaf1d8ae8881cfde52.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: cleanup regulator_ena_gpio_free()

Since only regulator_ena_gpio_request() allocates rdev->ena_pin, and it
guarantees that same gpiod gets same pin structure, it is enough to
compare just the pointers. Also we know there can be only one matching
entry on the list. Rework the code take advantage of the facts.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/3ff002c7aa3bd774491af4291a9df23541fcf892.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: plug of_node leak in regulator_register()'s error path

By calling device_initialize() earlier and noting that kfree(NULL) is
ok, we can save a bit of code in error handling and plug of_node leak.
Fixed commit already did part of the work.

Fixes: 9177514ce349 ("regulator: fix memory leak on error path of regulator_register()")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/f5035b1b4d40745e66bacd571bbbb5e4644d21a1.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: push allocation in set_consumer_device_supply() out of lock

Pull regulator_list_mutex into set_consumer_device_supply() and keep
allocations outside of it. Fourth of the fs_reclaim deadlock case.

Fixes: 45389c47526d ("regulator: core: Add early supply resolution for regulators")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/f0380bdb3d60aeefa9693c4e234d2dcda7e56747.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: push allocations in create_regulator() outside of lock

Move all allocations outside of the regulator_lock()ed section.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ #535 Not tainted
------------------------------------------------------
f2fs_discard-179:7/702 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
cb95b080 (&dcc->cmd_lock){+.+.}-{3:3}, at: __issue_discard_cmd+0xec/0x5f8

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

[...]

-> #3 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire.part.11+0x40/0x50
fs_reclaim_acquire+0x24/0x28
__kmalloc_track_caller+0x54/0x218
kstrdup+0x40/0x5c
create_regulator+0xf4/0x368
regulator_resolve_supply+0x1a0/0x200
regulator_register+0x9c8/0x163c

[...]

other info that might help us debug this:

Chain exists of:
regulator_list_mutex --> &sit_i->sentry_lock --> &dcc->cmd_lock

[...]

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/6eebc99b2474f4ffaa0405b15178ece0e7e4f608.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: push allocation in regulator_ena_gpio_request() out of lock

Move another allocation out of regulator_list_mutex-protected region, as
reclaim might want to take the same lock.

WARNING: possible circular locking dependency detected
5.7.13+ #534 Not tainted
------------------------------------------------------
kswapd0/383 is trying to acquire lock:
c0e5d920 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x2c0

but task is already holding lock:
c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire.part.11+0x40/0x50
fs_reclaim_acquire+0x24/0x28
kmem_cache_alloc_trace+0x40/0x1e8
regulator_register+0x384/0x1630
devm_regulator_register+0x50/0x84
reg_fixed_voltage_probe+0x248/0x35c
[...]
other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(regulator_list_mutex);
lock(fs_reclaim);
lock(regulator_list_mutex);

*** DEADLOCK ***
[...]
2 locks held by kswapd0/383:
#0: c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
#1: cb70e5e0 (hctx->srcu){....}-{0:0}, at: hctx_lock+0x60/0xb8
[...]

Fixes: 541d052d7215 ("regulator: core: Only support passing enable GPIO descriptors")
[this commit only changes context]
Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
[this is when the regulator_list_mutex was introduced in reclaim locking path]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/41fe6a9670335721b48e8f5195038c3d67a3bf92.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: push allocation in regulator_init_coupling() outside of lock

Allocating memory with regulator_list_mutex held makes lockdep unhappy
when memory pressure makes the system do fs_reclaim on eg. eMMC using
a regulator. Push the lock inside regulator_init_coupling() after the
allocation.

======================================================
WARNING: possible circular locking dependency detected
5.7.13+ #533 Not tainted
------------------------------------------------------
kswapd0/383 is trying to acquire lock:
cca78ca4 (&sbi->write_io[i][j].io_rwsem){++++}-{3:3}, at: __submit_merged_write_cond+0x104/0x154
but task is already holding lock:
c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire.part.11+0x40/0x50
fs_reclaim_acquire+0x24/0x28
__kmalloc+0x54/0x218
regulator_register+0x860/0x1584
dummy_regulator_probe+0x60/0xa8
[...]
other info that might help us debug this:

Chain exists of:
&sbi->write_io[i][j].io_rwsem --> regulator_list_mutex --> fs_reclaim

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(regulator_list_mutex);
lock(fs_reclaim);
lock(&sbi->write_io[i][j].io_rwsem);
*** DEADLOCK ***

1 lock held by kswapd0/383:
#0: c0e38518 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x50
[...]

Fixes: d8ca7d184b33 ("regulator: core: Introduce API for regulators coupling customization")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1a889cf7f61c6429c9e6b34ddcdde99be77a26b6.1597195321.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix memory leak on error path of regulator_register()

The change corrects registration and deregistration on error path
of a regulator, the problem was manifested by a reported memory
leak on deferred probe:

as3722-regulator as3722-regulator: regulator 13 register failed -517

# cat /sys/kernel/debug/kmemleak
unreferenced object 0xecc43740 (size 64):
comm "swapper/0", pid 1, jiffies 4294937640 (age 712.880s)
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2e 32 34 00 5a 5a 5a regulator.24.ZZZ
5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
backtrace:
[<0c4c3d1c>] __kmalloc_track_caller+0x15c/0x2c0
[<40c0ad48>] kvasprintf+0x64/0xd4
[<109abd29>] kvasprintf_const+0x70/0x84
[<c4215946>] kobject_set_name_vargs+0x34/0xa8
[<62282ea2>] dev_set_name+0x40/0x64
[<a39b6757>] regulator_register+0x3a4/0x1344
[<16a9543f>] devm_regulator_register+0x4c/0x84
[<51a4c6a1>] as3722_regulator_probe+0x294/0x754
...

The memory leak problem was introduced as a side ef another fix in
regulator_register() error path, I believe that the proper fix is
to decouple device_register() function into its two compounds and
initialize a struct device before assigning any values to its fields
and then using it before actual registration of a device happens.

This lets to call put_device() safely after initialization, and, since
now a release callback is called, kfree(rdev->constraints) shall be
removed to exclude a double free condition.

Fixes: a3cde9534ebd ("regulator: core: fix regulator_register() error paths to properly release rdev")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Wen Yang <wenyang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20200724005013.23278-1-vz@mleia.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add destroy_regulator()

Part of the regulator_get() code is already factored out into
create_regulator(). This patch factors out some of the regulator_put()
code into destroy_regulator() so that create_regulator() has a
corresponding unwind function. Subsequent patches will use this
function.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200716042053.1927676-3-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Allow regulators to verify enabled during enable()

Some regulators might need to verify that they have indeed been enabled
after the enable() call is made and enable_time delay has passed.

This is implemented by repeatedly checking is_enabled() upto
poll_enabled_time, waiting for the already calculated enable delay in
each iteration.

Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20200622124110.20971-2-sumit.semwal@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add regulator bypass trace points

Add new trace points for the start and end of enabling bypass on a
regulator, to allow monitoring of when regulators are moved into bypass
and how long that takes.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200529152216.9671-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: extract voltage balancing code to the separate function

Move the coupled regulators voltage balancing code to the separate
function and allow to call it from the custom regulator couplers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200529124940.10675-2-m.szyprowski@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Revert "Use driver_deferred_probe_timeout for regulator_init_complete_work"

This reverts commit dca0b44957e5 ("regulator: Use
driver_deferred_probe_timeout for regulator_init_complete_work"),
as we ended up reverting the default deferred_probe_timeout
value back to zero, to preserve behavior with 5.6 we need to
decouple the regulator timeout which was previously 30 seconds.

This avoids breaking some systems that depend on the regulator
timeout but don't require the deferred probe timeout.

Cc: linux-pm@vger.kernel.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200429172349.55979-1-john.stultz@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

regulator: use consumer->supply_name in debugfs/regulator_summary

Make it easier to identify regulator consumers when consumer device
uses more than one supply.

Before:

regulator ena use open bypass voltage current min max
-----------------------------------------------------------------------------------
regulator-dummy 1 0 2 0 0mV 0mA 0mV 0mV
1-0010 0mV 0mV
1-0010 0mV 0mV

After:

regulator ena use open bypass voltage current min max
-----------------------------------------------------------------------------------
regulator-dummy 1 0 2 0 0mV 0mA 0mV 0mV
1-0010-vccio 0mV 0mV
1-0010-vcc33 0mV 0mV

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/731a4b299c6ae0ee9d8995157600a3477f21a36c.1585959068.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Avoid device name duplication in NORMAL_GET

With current code:
st-gyro-i2c i2c-PRP0001:00: i2c-PRP0001:00 supply vdd not found, using dummy regulator

which looks a bit oververbose.

Replace this with simplified format string for the above case, and drop
"deviceless" case since for all dev_*() macros used in _regulator_get()
the "(null)" will be printed anyway.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200312183245.1612-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Use driver_deferred_probe_timeout for regulator_init_complete_work

The regulator_init_complete_work logic defers the cleanup for an
arbitrary 30 seconds of time to allow modules loaded by userland
to start.

This arbitrary timeout is similar to the
driver_deferred_probe_timeout value, and its been suggested we
align these so users have a method to extend the timeouts as
needed.

So this patch changes the logic to use the
driver_deferred_probe_timeout value for the delay value if it
is set (using a delay of 0 if it is not).

Cc: linux-pm@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/r/20200225050828.56458-7-john.stultz@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

regulator: core: Fix exported symbols to the exported GPL version

Change the exported symbols introduced by commit e9153311491da
("regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage")
from EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL(), like is used for all the core
parts.

Fixes: e9153311491da ("regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200120123921.1204339-1-enric.balletbo@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage

`cat /sys/kernel/debug/regulator/regulator_summary` ends on a deadlock
when you have a voltage controlled regulator (vctrl).

The problem is that the vctrl_get_voltage() and vctrl_set_voltage() calls the
regulator_get_voltage() and regulator_set_voltage() and that will try to lock
again the dependent regulators (the regulator supplying the control voltage).

Fix the issue by exporting the unlocked version of the regulator_get_voltage()
and regulator_set_voltage() API so drivers that need it, like the voltage
controlled regulator driver can use it.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Reported-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200116094543.2847321-1-enric.balletbo@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: avoid unneeded .list_voltage calls

Inside machine_constraints_voltage() a loop is in charge of verifying that
each of the defined voltages are within the configured constraints and
that those constraints are in fact compatible with the available voltages'
list.

When the registered regulator happens to be defined with a wide range of
possible voltages the above O(n) loop can be costly.
Moreover since this behaviour is triggered during the registration process,
it means also that it can be easily triggered at probe time, slowing down
considerably some module loading.

On the other side if such wide range of voltage values happens to be also
continuous and without discontinuity of any kind, the above potentially
cumbersome operation is also useless.

For these reasons, avoid such .list_voltage poll loop when regulator is
described as 'continuous_voltage_range' as is, indeed, similarly already
done inside regulator_is_supported_voltage().

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20191209125239.46054-1-cristian.marussi@arm.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix regulator_register() error paths to properly release rdev

There are several issues with the error handling code of
the regulator_register() function:
ret = device_register(&rdev->dev);
if (ret != 0) {
put_device(&rdev->dev); --> rdev released
goto unset_supplies;
}
...
unset_supplies:
...
unset_regulator_supplies(rdev); --> use-after-free
...
clean:
if (dangling_of_gpiod)
gpiod_put(config->ena_gpiod);
kfree(rdev); --> double free

We add a variable to record the failure of device_register() and
move put_device() down a bit to avoid the above issues.

Fixes: c438b9d01736 ("regulator: core: Move registration of regulator device")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20191201030250.38074-1-wenyang@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix use after free issue

This is caused by dereferencing 'rdev' after put_device() in
the _regulator_get()/_regulator_put() functions.
This patch just moves the put_device() down a bit to avoid the
issue.

Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20191124145835.25999-1-wenyang@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Let boot-on regulators be powered off

Boot-on regulators are always kept on because their use_count value
is now incremented at boot time and never cleaned.

Only increment count value for alway-on regulators.
regulator_late_cleanup() is now able to power off boot-on regulators
when unused.

Fixes: 05f224ca6693 ("regulator: core: Clean enabling always-on regulators + their supplies")
Signed-off-by: Pascal Paillet <p.paillet@st.com>
Link: https://lore.kernel.org/r/20191113102737.27831-1-p.paillet@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't try to remove device links if add failed

device_link_add() might not always succeed depending on the type of
device link and the rest of the dependencies in the system. If
device_link_add() didn't succeed, then we shouldn't try to remove the
link later on as it might remove a link someone else created.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20191115000438.45970-1-saravanak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Allow generic coupling only for always-on regulators

The generic voltage balancer doesn't work correctly if one of regulator
couples turns off. Currently there are no users in kernel for that case,
although let's explicitly show that this case is unsupported for those who
will try to use that feature.

Link: https://lore.kernel.org/linux-samsung-soc/20191008170503.yd6GscYPLxjgrXqDuCO7AJc6i6egNZGJkVWHLlCxvA4@z/
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20191025002240.25288-2-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Release coupled_rdevs on regulator_init_coupling() error

This patch fixes memory leak which should happen if regulator's coupling
fails to initialize.

Fixes: d8ca7d184b33 ("regulator: core: Introduce API for regulators coupling customization")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20191025002240.25288-1-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: make regulator_register() EPROBE_DEFER aware

Sometimes it can happen that the regulator_of_get_init_data() can't
retrieve the config due to a not probed device the regulator depends on.
Fix that by checking the return value of of_parse_cb() and return
EPROBE_DEFER in such cases.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Link: https://lore.kernel.org/r/20190917154021.14693-4-m.felsch@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix error return for /sys access

regulator_uV_show() is missing error handling if regulator_get_voltage_rdev()
returns negative values. Instead it prints the errno as a string, e.g. -EINVAL
as "-22" which could be interpreted as -22 µV.

We also do not need to hold the lock while converting the integer to a string.

Reported-by: Adam Ford <aford173@gmail.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/f37f2a1276efcb34cf3b7f1a25481175be048806.1568143348.git.hns@goldelico.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Defer init completion for a while after late_initcall

The kernel has no way of knowing when we have finished instantiating
drivers, between deferred probe and systems that build key drivers as
modules we might be doing this long after userspace has booted. This has
always been a bit of an issue with regulator_init_complete since it can
power off hardware that's not had it's driver loaded which can result in
user visible effects, the main case is powering off displays. Practically
speaking it's not been an issue in real systems since most systems that
use the regulator API are embedded and build in key drivers anyway but
with Arm laptops coming on the market it's becoming more of an issue so
let's do something about it.

In the absence of any better idea just defer the powering off for 30s
after late_initcall(), this is obviously a hack but it should mask the
issue for now and it's no more arbitrary than late_initcall() itself.
Ideally we'd have some heuristics to detect if we're on an affected
system and tune or skip the delay appropriately, and there may be some
need for a command line option to be added.

Link: https://lore.kernel.org/r/20190904124250.25844-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Tested-by: Lee Jones <lee.jones@linaro.org>
Cc: stable@vger.kernel.org

regulator: core: Add label to collate of_node_put() statements

In function of_get_child_regulator(), the loop for_each_child_of_node()
contains two mid-loop return statements, each preceded by a statement
putting child. In order to reduce this repetition, create a new label,
err_node_put, that puts child and then returns the required value;
edit the mid-loop return blocks to instead go to this new label.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190815053704.32156-1-nishkadg.linux@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add of_node_put() before return

Each iteration of for_each_child_of_node puts the previous node, but in
the case of a return from the middle of the loop, there is no put, thus
causing a memory leak. Hence add an of_node_put before the return in
two places.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190804162023.5673-1-nishkadg.linux@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: implement selector stepping

Some regulators require that the requested voltage be reached gradually
by setting all or some of the intermediate values. Implement a new field
in the regulator description struct that allows users to specify the
number of selectors by which the regulator API should step when ramping
the voltage up/down.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20190703161035.31808-2-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Expose some of core functions needed by couplers

Expose some of internal functions that are required for implementation of
customized regulator couplers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Introduce API for regulators coupling customization

Right now regulator core supports only one type of regulators coupling,
the "voltage max-spread" which keeps voltages of coupled regulators in a
given range from each other. A more sophisticated coupling may be required
in practice, one example is the NVIDIA Tegra SoCs which besides the
max-spreading have other restrictions that must be adhered. Introduce API
that allow platforms to provide their own customized coupling algorithms.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Make entire header comment C++ style

Makes things look more consistent.

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

docs: timers: convert docs to ReST and rename to *.rst

The conversion here is really trivial: just a bunch of title
markups and very few puntual changes is enough to make it to
be parsed by Sphinx and generate a nice html.

The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

regulator: core: Slightly improve readability of _regulator_get_enable_time

The logic is equivalent, but it looks more straightforward this way:
If rdev->desc->ops->enable_time is set, call it.
Otherwise fallback to return rdev->desc->enable_time.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: simplify return value on suported_voltage

All the current clients of this API assume that 0 corresponds
to a failure and non-zero to a pass therefore ignoring the need to
handle a negative error code.

This commit modifies the API to follow that standard since returning a
negative (EINVAL) doesn't seem to provide enough value to justify
the need to handle it.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: do not report EPROBE_DEFER as error but as debug

Temporary failures to get a regulator (EPROBE_DEFER) should be logged
as debug information instead of errors.

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Actually put the gpiod after use

I went to great lengths to hand over the management of the GPIO
descriptors to the regulator core, and some stray rebased
oneliner in the old patch must have been assuming the devices
were still doing devres management of it.

We handed the management over to the regulator core, so of
course the regulator core shall issue gpiod_put() when done.

Sorry for the descriptor leak.

Fixes: 541d052d7215 ("regulator: core: Only support passing enable GPIO descriptors")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Avoid potential deadlock on regulator_unregister

Lockdep reports the following issue on my setup:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock((work_completion)(&(&rdev->disable_work)->work));
lock(regulator_list_mutex);
lock((work_completion)(&(&rdev->disable_work)->work));
lock(regulator_list_mutex);

The problem is that regulator_unregister takes the
regulator_list_mutex and then calls flush_work on disable_work. But
regulator_disable_work calls regulator_lock_dependent which will
also take the regulator_list_mutex. Resulting in a deadlock if the
flush_work call actually needs to flush the work.

Fix this issue by moving the flush_work outside of the
regulator_list_mutex. The list mutex is not used to guard the point at
which the delayed work is queued, so its use adds no additional safety.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix error path for regulator_set_voltage_unlocked

During several error paths in the function
regulator_set_voltage_unlocked() the value of 'ret' can take on negative
error values. However, in calls that go through the 'goto out' statement,
this return value is lost and return 0 is used instead, indicating a
'pass'.

There are several cases where this function should legitimately return a
fail instead of a pass: one such case includes constraints check during
voltage selection in the call to regulator_check_voltage(), which can
have -EINVAL for the case when an unsupported voltage is incorrectly
requested. In that case, -22 is expected as the return value, not 0.

Fixes: 9243a195be7a ("regulator: core: Change voltage setting path")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix application of "drop lockdep annotation in drms_uA_update()"

[The original commit was sent against -next but needed to be sent as a
bugfix, however -next had some additional changes which needed to be
reverted. Now everything is all in one branch applying the rest of the
changes to fix up the merge issue -- broonie]

commit e5e21f70bfd3 ("regulator: core: Take lock before applying system
load") took the regulator lock before calling drms_uA_update() in order
to silence a lockdep warning during regulator_register().

However, we are not supposed to need locks at this point as the regulator
is in the process of being registered, so there should be no possibility
of concurrent access.

Instead, remove the unnecessary locking and simply drop the lockdep
annotation, since it is no longer valid.

Fixes: e5e21f70bfd3 ("regulator: core: Take lock before applying system load")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Log forbidden DRMS operation

When REGULATOR_CHANGE_DRMS is not set, drms_uA_update is a no-op.
It used to print a debug message, which was dropped in commit
8a34e979f684 ("regulator: refactor valid_ops_mask checking code")

Let's bring the debug message back, because it helps find missing
regulator-allow-set-load properties.

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Drop lockdep annotation in drms_uA_update()

commit e5e21f70bfd3 ("regulator: core: Take lock before applying system
load") took the regulator lock before calling drms_uA_update() in order
to silence a lockdep warning during regulator_register().

However, we are not supposed to need locks at this point as the regulator
is in the process of being registered, so there should be no possibility
of concurrent access.

Instead, remove the unnecessary locking and simply drop the lockdep
annotation, since it is no longer valid.

Fixes: e5e21f70bfd3 ("regulator: core: Take lock before applying system load")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: remove unused rdev_get_supply()

This is a remnant of commit 70a7fb80e85a ("regulator: core: Fix nested
locking of supplies").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Take lock before applying system load

Take the regulator lock before applying system load.

Fixes the following lockdep splat:

[ 5.583581] WARNING: CPU: 1 PID: 16 at drivers/regulator/core.c:925 drms_uA_update+0x114/0x360
[ 5.588467] Modules linked in:
[ 5.596833] CPU: 1 PID: 16 Comm: kworker/1:0 Not tainted 5.0.0-rc6-next-20190213-00002-g0fce66ab480f #18
[ 5.599933] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
[ 5.609544] Workqueue: events qcom_channel_state_worker
[ 5.616209] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 5.621152] pc : drms_uA_update+0x114/0x360
[ 5.626006] lr : drms_uA_update+0x110/0x360
[ 5.630084] sp : ffff0000124b3490
[ 5.634242] x29: ffff0000124b3490 x28: ffff800005326e00
[ 5.637735] x27: ffff0000124b35f8 x26: 000000000032bc48
[ 5.643117] x25: ffff800004c7e800 x24: ffff800004c6d500
[ 5.648411] x23: ffff800004c38a80 x22: 00000000000000d1
[ 5.653706] x21: 00000000001ab3f0 x20: ffff800004c7e800
[ 5.659001] x19: ffff0000114c3000 x18: ffffffffffffffff
[ 5.664297] x17: 0000000000000000 x16: 0000000000000000
[ 5.669592] x15: ffff0000114c3808 x14: 0720072007200720
[ 5.674888] x13: 00000000199c9b28 x12: ffff80002bcccc40
[ 5.680183] x11: ffff000012286000 x10: ffff0000114c3808
[ 5.685477] x9 : 0720072007200720 x8 : ffff000010e9e808
[ 5.690772] x7 : ffff0000106da568 x6 : 0000000000000000
[ 5.696067] x5 : 0000000000000000 x4 : 0000000000000000
[ 5.701362] x3 : 0000000000000004 x2 : 0000000000000000
[ 5.706658] x1 : 0000000000000000 x0 : 0000000000000000
[ 5.711952] Call trace:
[ 5.717223] drms_uA_update+0x114/0x360
[ 5.719405] regulator_register+0xb30/0x1140
[ 5.723230] devm_regulator_register+0x4c/0xa8
[ 5.727745] rpm_reg_probe+0xfc/0x1b0
[ 5.731992] platform_drv_probe+0x50/0xa0
[ 5.735727] really_probe+0x20c/0x2b8
[ 5.739718] driver_probe_device+0x58/0x100
[ 5.743368] __device_attach_driver+0x90/0xd0
[ 5.747363] bus_for_each_drv+0x64/0xc8
[ 5.751870] __device_attach+0xd8/0x138
[ 5.755516] device_initial_probe+0x10/0x18
[ 5.759341] bus_probe_device+0x98/0xa0
[ 5.763502] device_add+0x3d0/0x640
[ 5.767319] of_device_add+0x48/0x58
[ 5.770793] of_platform_device_create_pdata+0xb0/0x128
[ 5.774629] of_platform_bus_create+0x174/0x370
[ 5.779569] of_platform_populate+0x78/0xe0
[ 5.784082] qcom_smd_rpm_probe+0x80/0xa0
[ 5.788245] rpmsg_dev_probe+0x114/0x1a0
[ 5.792411] really_probe+0x20c/0x2b8
[ 5.796401] driver_probe_device+0x58/0x100
[ 5.799964] __device_attach_driver+0x90/0xd0
[ 5.803960] bus_for_each_drv+0x64/0xc8
[ 5.808468] __device_attach+0xd8/0x138
[ 5.812115] device_initial_probe+0x10/0x18
[ 5.815936] bus_probe_device+0x98/0xa0
[ 5.820099] device_add+0x3d0/0x640
[ 5.823916] device_register+0x1c/0x28
[ 5.827391] rpmsg_register_device+0x4c/0x90
[ 5.831216] qcom_channel_state_worker+0x170/0x298
[ 5.835651] process_one_work+0x294/0x6e8
[ 5.840241] worker_thread+0x40/0x450
[ 5.844318] kthread+0x11c/0x120
[ 5.847961] ret_from_fork+0x10/0x18
[ 5.851260] irq event stamp: 9090
[ 5.854820] hardirqs last enabled at (9089): [<ffff000010160798>] console_unlock+0x3e0/0x5b0
[ 5.858086] hardirqs last disabled at (9090): [<ffff0000100817cc>] do_debug_exception+0x104/0x140
[ 5.866596] softirqs last enabled at (9086): [<ffff000010082024>] __do_softirq+0x474/0x574
[ 5.875446] softirqs last disabled at (9079): [<ffff0000100f2254>] irq_exit+0x13c/0x148
[ 5.883598] ---[ end trace 6984ef7f081afa21 ]---

Fixes: fa94e48e13a1 ("regulator: core: Apply system load even if no consumer loads")
Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix device unlinking

Device links are refcounted, device_link_remove() has to be called as
many times as device_link_add().

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Only support passing enable GPIO descriptors

Now that we changed all providers to pass descriptors into the core
for enable GPIOs instead of a global GPIO number, delete the support
for passing GPIO numbers in, and we get a cleanup and size reduction
in the core, and from a GPIO point of view we use the modern, cleaner
interface.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fixed/gpio: Pull inversion/OD into gpiolib

This pushes the handling of inversion semantics and open drain
settings to the GPIO descriptor and gpiolib. All affected board
files are also augmented.

This is especially nice since we don't have to have any
confusing flags passed around to the left and right littering
the fixed and GPIO regulator drivers and the regulator core.
It is all just very straight-forward: the core asks the GPIO
line to be asserted or deasserted and gpiolib deals with the
rest depending on how the platform is configured: if the line
is active low, it deals with that, if the line is open drain,
it deals with that too.

Cc: Alexander Shiyan <shc_work@mail.ru> # i.MX boards user
Cc: Haojian Zhuang <haojian.zhuang@gmail.com> # MMP2 maintainer
Cc: Aaro Koskinen <aaro.koskinen@iki.fi> # OMAP1 maintainer
Cc: Tony Lindgren <tony@atomide.com> # OMAP1,2,3 maintainer
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> # EM-X270 maintainer
Cc: Robert Jarzmik <robert.jarzmik@free.fr> # EZX maintainer
Cc: Philipp Zabel <philipp.zabel@gmail.com> # Magician maintainer
Cc: Petr Cvek <petr.cvek@tul.cz> # Magician
Cc: Robert Jarzmik <robert.jarzmik@free.fr> # PXA
Cc: Paul Parsons <lost.distance@yahoo.com> # hx4700
Cc: Daniel Mack <zonque@gmail.com> # Raumfeld maintainer
Cc: Marc Zyngier <marc.zyngier@arm.com> # Zeus maintainer
Cc: Geert Uytterhoeven <geert+renesas@glider.be> # SuperH pinctrl/GPIO maintainer
Cc: Russell King <rmk+kernel@armlinux.org.uk> # SA1100
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Janusz Krzysztofik <jmkrzyszt@gmail.com> #OMAP1 Amstrad Delta
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: provide rdev_get_regmap()

Provide a helper allowing to access regulator's regmap.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix trivial language typos

Fix few trivial language typos in core and drivers.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: convert to DEFINE_SHOW_ATTRIBUTE

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Clean enabling always-on regulators + their supplies

At the end of regulator_resolve_supply() we have historically turned
on our supply in some cases. This could be for one of two reasons:

1. If resolving supplies was happening before the call to
set_machine_constraints() we needed to predict if
set_machine_constraints() was going to turn the regulator on and we
needed to preemptively turn the supply on.
2. Maybe set_machine_constraints() happened before we could resolve
supplies (because we failed the first time to resolve) and thus we
might need to propagate an enable that already happened up to our
supply.

Historically regulator_resolve_supply() used _regulator_is_enabled()
to decide whether to turn on the supply.

Let's change things a little bit. Specifically:

1. Let's try to enable the supply and the regulator in the same place,
both in set_machine_constraints(). This means that we have exactly
the same logic for enabling the supply and the regulator.
2. Let's properly set use_count when we enable always-on or boot-on
regulators even for those that don't have supplies. The previous
commit 1fc12b05895e ("regulator: core: Avoid propagating to
supplies when possible") only did this right for regulators with
supplies.
3. Let's make it clear that the only time we need to enable the supply
in regulator_resolve_supply() is if the main regulator is currently
in use. By using use_count (like the rest of the code) to decide
if we're going to enable our supply we keep everything consistent.

Overall the new scheme should be cleaner and easier to reason about.
In addition to fixing regulator_summary to be more correct (because of
the more correct use_count), this change also has the effect of no
longer using _regulator_is_enabled() in this code path.
_regulator_is_enabled() could return an error code for some regulators
at bootup (like RPMh) that can't read their initial state. While one
can argue that the design of those regulators is sub-optimal, the new
logic sidesteps this brokenness. This fix in particular fixes
observed problems on Qualcomm sdm845 boards which use the
above-mentioned RPMh regulator. Those problems were made worse by
commit 1fc12b05895e ("regulator: core: Avoid propagating to supplies
when possible") because now we'd think at bootup that the SD
regulators were already enabled and we'd never try them again.

Fixes: 1fc12b05895e ("regulator: core: Avoid propagating to supplies when possible")
Reported-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Track dangling GPIO descriptors

If a GPIO descriptor is passed to the regulator_register()
function inside the config->ena_gpiod callers must be
sure that once they call this API the regulator core
owns that descriptor and will make sure to issue
gpiod_put() on it, no matter whether the call is
successful or not.

For device tree regulators, the regulator core will
automatically set up regulator init data from the device
tree when registering a regulator by calling
regulator_of_get_init_data() which in turn calls down to
the regulator driver's .of_parse_cb() callback.
This callback (in drivers such as for max77686) may also
choose to fill in the config->ena_gpiod field with a GPIO
descriptor.

Harden the errorpath of regulator_register() to
properly gpiod_put() any passed in cfg->ena_gpiod
or any gpiod coming from the device tree on any type
of error.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Apply system load even if no consumer loads

Prior to commit 5451781dadf8 ("regulator: core: Only count load for
enabled consumers") we used to always add up the total load on every
enable in _regulator_enable(). After that commit we only updated the
total load when enabling / disabling a regulator where a consumer
specified a load or when changing the consumer load on an enabled
regulator.

The problem with the new scheme is that if there is a system load
specified for a regulator but no consumers specify a load then we
never account for it.

Let's account for the system load in set_machine_constraints().

NOTE: with the new scheme we end up with a bit of a quandry. What if
someone specifies _both_ an initial mode and a system load? If we
take the system load into account right at init time then it will
effectively clobber the initial mode. We'll resolve this by saying
that if both are specified then the initial mode will win. The system
load will then only take effect if/when a consumer specifies a load.
If no consumers ever specify a load then the initial mode will persist
and the system load will have no effect.

Fixes: 5451781dadf8 ("regulator: core: Only count load for enabled consumers")
Reported-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: enable power when setting up constraints

When a regulator is marked as always on, it is enabled early on, when
checking and setting up constraints. It makes the assumption that the
bootloader properly initialized the regulator, and just in case enables
the regulator anyway.

Some constraints however currently get missed, such as the soft-start
and ramp-delay. This causes the regulator to be enabled, without the
soft-start and ramp-delay being applied, which in turn can cause
high-currents or other start-up problems.

By moving the always-enabled constraints later in the constraints check,
we can at least ensure all constraints for the regulator are followed.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Priit Laes <plaes@plaes.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Avoid propagating to supplies when possible

When we called regulator_enable() on a regulator we'd end up
propagating that call all the way up the chain every time. This is a
bit of a waste of time. A child regulator already refcounts its own
enables so it should avoid passing on to its parent unless the
refcount transitioned between 0 and 1.

Historically this hasn't been a huge problem since we skipped dealing
with enable for always-on regulators. In a previous patch, however,
we removed the always-on optimization. On one system, the debugfs
regulator_summary was now showing a "use_count" of 33 for a top-level
regulator.

Let's implement this optimization. This turns out to be fairly
trivial with the recent reorganization of the regulator core.

NOTE: as part of this patch I'll make "always-on" regulators start
with a use count of 1. This keeps the counts clean when recursively
resolving regulators.

ALSO NOTE: this commit also contains somewhat of a bug fix to
regulator_force_disable(). It was incorrectly looping over
"rdev->open_count" when it should have been looping over use_count.
We have to touch that code anyway (since we should no longer loop at
all), so we'll fix it together in one patch. Also: since this comes
after commit f8702f9e4aa7 ("regulator: core: Use ww_mutex for
regulators locking") we can now move to use _regulator_disable() for
our supply and keep it in the lock.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Only count load for enabled consumers

In general when the consumer of a regulator requests that the
regulator be disabled it no longer will be drawing much load from the
regulator--it should just be the leakage current and that should be
very close to 0.

Up to this point the regulator framework has continued to count a
consumer's load request for disabled regulators. This has led to code
patterns that look like this:

enable_my_thing():
regular_set_load(reg, load_uA)
regulator_enable(reg)

disable_my_thing():
regulator_disable(reg)
regulator_set_load(reg, 0)

Sometimes disable_my_thing() sets a nominal (<= 100 uA) load instead
of setting a 0 uA load. I will make the assertion that nearly all (if
not all) places where we set a nominal load of 100 uA or less we end
up with a result that is the same as if we had set a load of 0 uA.
Specifically:
- The whole point of setting the load is to help set the operating
mode of the regulator. Higher loads may need less efficient
operating modes.
- The only time this matters at all is if there is another consumer of
the regulator that wants the regulator on. If there are no other
consumers of the regulator then the regulator will turn off and we
don't care about the operating mode.
- If there's another consumer that actually wants the regulator on
then presumably it is requesting a load that makes our nominal
<= 100 uA load insignificant.

A quick survey of the existing callers to regulator_set_load() to see
how everyone uses it:

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't double-disable supplies in regulator_disable_deferred()

In the commit f8702f9e4aa7 ("regulator: core: Use ww_mutex for
regulators locking") disabling of the supply was moved into
_regulator_disable(). That means regulator_disable_work() shouldn't
be disabling since that double-disables the supply.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Properly expose requested_microamps in sysfs

The "requested_microamps" sysfs attribute was only being exposed for
"current" regulators. This didn't make sense. Allow it to be exposed
always.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Export regulator_lock and regulator_unlock

This fixes compiling regulator drivers that use these function when
these drivers are built as kernel modules.

Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Keep regulators-list locked while traversing the list

It's unlikely that regulators may disappear/appear while regulators
debug-summary is being prepared, but let's be consistent and avoid that
situation.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Properly handle case where supply is the couple

Check whether supply regulator is the couple to avoid infinite recursion
during of locking.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use ww_mutex for regulators locking

Wait/wound mutex shall be used in order to avoid lockups on locking of
coupled regulators.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Suggested-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator/of_get_regulator: add child path to find the regulator supplier

when the VIR_LDO1 regulator supplier is it's brother,
we can't find the supplier.

example code :
&vir_regulator {
ldo0_vir: ldo0-virtual {
regulator-compatible = "VIR_LDO0";
regulator-name= "VIR_LDO0";
regulator-min-microvolt = <1000000>;
regulator-max-microvolt = <2000000>;
};
ldo1_vir: ldo1-virtual {
regulator-compatible = "VIR_LDO1";
regulator-name= "VIR_LDO1";
regulator-min-microvolt = <1000000>;
regulator-max-microvolt = <3000000>;
ldo1-supply = <&ldo0_vir>;
};
...
}

so we add the child ptah to find the suppier.

Signed-off-by: zoro <long17.cool@163.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Decouple regulators on regulator_unregister()

Regulators shall be uncoupled if one of the couples disappear.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add new max_uV_step constraint

On NVIDIA Tegra30 there is a requirement for regulator "A" to have voltage
higher than voltage of regulator "B" by N microvolts, the N value changes
depending on the voltage of regulator "B". This is similar to min-spread
between voltages of regulators, the difference is that the spread value
isn't fixed. This means that extra carefulness is required for regulator
"A" to drop its voltage without violating the requirement, hence its
voltage should be changed in steps so that its couple "B" could follow
(there is also max-spread requirement).

Add new "max_uV_step" constraint that breaks voltage change into several
steps, each step is limited by the max_uV_step value.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't allow to get regulator until all couples resolved

Don't allow to get regulator until all of its couples resolved because
consumer will get EPERM and coupling shall be transparent for the drivers.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Mutually resolve regulators coupling

If registered regulator found a couple, then the couple can find the
registered regulator too and hence coupling can be mutually resolved
at the registration time.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Change voltage setting path

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.

Uncoupled regulators should be a special case of coupled regulators, so
they should share a common voltage setting path. When enabling,
disabling or setting voltage of a coupled regulator, all coupled
regulators should be locked. Regulator's supplies should be locked, when
setting voltage of a single regulator. Enabling a coupled regulator or
setting its voltage should not be possible if some of its coupled
regulators, has not been registered.

Add function for locking coupled regulators and supplies. Extract
a new function regulator_set_voltage_rdev() from
regulator_set_voltage_unlocked(), which is called when setting
voltage of a single regulator.

Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add voltage balancing mechanism

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, change its voltage so that it doesn't break 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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Support regulators where voltage ranges are selectable

For example ROHM BD71837 and ROHM BD71847 Power management ICs have
regulators which provide multiple linear ranges. Ranges can be
selected by individual non contagious bit in vsel register. Add
regmap helper functions for selecting ranges.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix crash caused by null driver data

dev_set_drvdata() needs to be called before device_register()
exposes device to userspace. Otherwise kernel crashes after it
gets null pointer from dev_get_drvdata() when userspace tries
to access sysfs entries.

[Removed backtrace for length -- broonie]

Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regulator: fix kernel-doc for regulator_suspend()

Fix kernel-doc warning:

../drivers/regulator/core.c:4479: warning: Excess function parameter 'state' description in 'regulator_suspend'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix useless O^2 complexity in suspend/resume

regulator_pm_ops with regulator_suspend and regulator_resume functions are
assigned to every regulator device registered in the system, so there is no
need to iterate over all again in them. Replace class_for_each_device()
construction with direct operation on the rdev embedded in the given
regulator device. This saves a lots of useless operations in suspend and
resume paths.

Fixes: f7efad10b5c4: regulator: add PM suspend and resume hooks
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix 'do-nothing' value for regulators without suspend state

Some regulators don't have all states defined and in such cases regulator
core should not assume anything. However in current implementation
of of_get_regulation_constraints() DO_NOTHING_IN_SUSPEND enable value was
set only for regulators which had suspend node defined, otherwise the
default 0 value was used, what means DISABLE_IN_SUSPEND. This lead to
broken system suspend/resume on boards, which had simple regulator
constraints definition (without suspend state nodes).

To avoid further mismatches between the default and uninitialized values
of the suspend enabled/disabled states, change the values of the them,
so default '0' means DO_NOTHING_IN_SUSPEND.

Fixes: 72069f9957a1: regulator: leave one item to record whether regulator is enabled
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regulator: core: Add locking to debugfs regulator_summary

Most functions that access the rdev lock the rdev mutex before looking
at data. ...but not the code that implements the debugfs
regulator_summary. It probably should though, so let's do it.

Note: this fixes no known issues. The problem was found only by code
inspection.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add consumer-requested load in regulator_summary

It's handy to see the load requested by a regulator consumer in the
regulator_summary. Add it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add the opmode to regulator_summary

It's handy to know what opmode a regulator has been configured to in
the summary. Add it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Link consumer with regulator driver

Add a device link between the consumer and the driver so that
the consumer is not suspended before the driver. The goal is to avoid
implementing suspend_late ops in regulator drivers.

Signed-off-by: pascal paillet <p.paillet@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Change suspend_late to suspend

Change suspend_late ops to suspend normal ops. The goal is to avoid
requesting all the regulator drivers to be operational in suspend late
phase.

Signed-off-by: pascal paillet <p.paillet@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Revert coupled regulator support again

Revert the last two commits of the voltage coupling mechanism patch set:

456e7cdf3b1a14e2606b8 regulator: core: Change voltage setting path
696861761a58d8c93605b regulator: core: Add voltage balancing mechanism

as they broke boot on OMAP again.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Change voltage setting path

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.

Uncoupled regulators should be a special case of coupled regulators, so
they should share a common voltage setting path. When enabling,
disabling or setting voltage of a coupled regulator, all coupled
regulators should be locked. Regulator's supplies should be locked, when
setting voltage of a single regulator. Enabling a coupled regulator or
setting its voltage should not be possible if some of its coupled
regulators, has not been registered.

Add function for locking coupled regulators and supplies. Extract
a new function regulator_set_voltage_rdev() from
regulator_set_voltage_unlocked(), which is called when setting
voltage of a single regulator.

Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add voltage balancing mechanism

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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Resolve coupled regulators

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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Make locks re-entrant

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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Allow for regulators that can't be read at bootup

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: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add missing blank line between functions

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

regulator: Fix resume from suspend to idle

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 57a0dd187956ea04 ("regulator: Fix suspend to idle"),
which fixed the suspend part.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Support passing an initialized GPIO enable descriptor

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: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix suspend to idle

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: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix build error

3d67fe950707 (regulator: core: Refactor regulator_list_voltage()) missed
one user of regulator_list_voltage(), update for that.

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

regulator: core: Refactor regulator_list_voltage()

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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Move of_find_regulator_by_node() to of_regulator.c

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: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: add PM suspend and resume hooks

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: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: empty the old suspend functions

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: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: leave one item to record whether regulator is enabled

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: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: make regulator voltage be an array to support more states

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: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: fix incorrect indentation of two assignment statements

Remove extraneous space to fix indentation on a couple of assignment
statements.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix a possible race in disable_work handling

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: Tirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Convert to using %pOF instead of full_name

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: Rob Herring <robh@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix size limit of supply_map

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: Haishan Zhou <zhssmail@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix voltage change propagations to supply regulators

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: Tirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Prioritise consumer mappings over regulator name

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: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Allow for asymmetric settling times

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: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Allow dummy regulators for supplies

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: Mark Brown <broonie@kernel.org>
Tested-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>

regulator: core: Only propagate voltage changes to if it can change voltages

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: Dong Aisheng <aisheng.dong@nxp.com>
Tested-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Add settling time for non-linear voltage transition

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: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Limit propagation of parent voltage count and list

Commit 26988efe11b1 ("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: 26988efe11b1 ("regulator: core: Allow to get voltage count and
list from parent")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix kerneldoc comments

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: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add new notification for enabling of regulator

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: Harald Geyer <harald@ccbib.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Mark supply_name const and duplicate it as such

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: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: use snprintf() instead of scnprintf()

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: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Resolve supplies before disabling unused regulators

After commit 66d228a2bf03 ("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: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix regulator_summary for deviceless consumers

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: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

regulator: core: simplify _regulator_get()

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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: have regulator_dev_lookup() return ERR_PTR-encoded errors

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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix typo in regulator_bulk_disable()

"re-enable" was misspelled as "reename".

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: simplify regulator_bulk_force_disable()

There is no need to have two loops there, we can store error for subsequent
reporting.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: have _regulator_get() accept get_type argument

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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: remove dead code in _regulator_get()

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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't use regulators as supplies until the parent is bound

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: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: add newline in debug message

This adds a trailing newline to a debug message.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Correct type of mode in regulator_mode_constrain

Every function handling the mode within the regulator core uses an unsigned
int for mode, except for regulator_mode_constrain. This patch changes the
type of mode within regulator_mode_constrain which fixes several instances
where we are passing pointers to unsigned ints then treating them as an int
within this function.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add new API to poll for error conditions

Regulator consumers can receive event notifications when
errors are reported to the driver, but currently, there is
no way for a regulator consumer to know when the error is over.

To allow a regulator consumer to poll for error conditions
add a new API: regulator_get_error_flags.

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: silence warning: "VDD1: ramp_delay not set"

commit 73e705bf81ce ("regulator: core: Add set_voltage_time op")

introduced a new rdev_warn() if the ramp_delay is 0.

Apparently, on omap3/twl4030 platforms with dynamic voltage
management this results in non-ending spurious messages like

[ 511.143066] VDD1: ramp_delay not set
[ 511.662322] VDD1: ramp_delay not set
[ 513.903625] VDD1: ramp_delay not set
[ 514.222198] VDD1: ramp_delay not set
[ 517.062835] VDD1: ramp_delay not set
[ 517.382568] VDD1: ramp_delay not set
[ 520.142791] VDD1: ramp_delay not set
[ 520.502593] VDD1: ramp_delay not set
[ 523.062896] VDD1: ramp_delay not set
[ 523.362701] VDD1: ramp_delay not set
[ 526.143035] VDD1: ramp_delay not set

I have observed this on GTA04 while it is reported to occur on
N900 as well: https://bugzilla.kernel.org/show_bug.cgi?id=178371

This patch makes the warning appear only in debugging mode.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: don't return error with inadequate reason

drms_uA_update() always returns failure when it cannot find regulator's
input voltage. But if hardware supports load configuration with
ops->set_load() and the input regulator isn't specified with valid reason
such as the input regulator is battery, not finding input voltage is
normal so such case should not return with an error.

Avoid such inadequate error return by checking input/output voltages
only when drms_uA_update() is about to configure load with enum based
ops->set_mode().

Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add set_voltage_time op

The new op is analogous to set_voltage_time_sel. It can be used by
regulators which don't have a table of discrete voltages. The function
returns the time for the regulator output voltage to stabilize after
being set to a new value, in microseconds. If the op is not set a
default implementation is used to calculate the delay.

This change also removes the ramp_delay calculation in the PWM
regulator, since the driver now uses the core code for the calculation
of the delay.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't skip set_voltage_time when ramp delay disabled

The current code assumes that only the ramp_delay is used to determine
the time needed for the voltage to stabilize. This may be true for the
calculation done by regulator_set_voltage_time_sel(), however regulators
can implement their own set_voltage_time_sel() op which would be skipped
if no ramp delay is specified. Remove the check in
_regulator_do_set_voltage(), the functions calculating the ramp delay
return 0 anyway when the ramp delay is not configured.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Simplify error flow in _regulator_do_set_voltage()

If the voltage can not be set jump to the end of the function. This
avoids having to check for an error multiple times and eliminates one
level of nesting in a follow-up change.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use local ops variable in _regulator_do_set_voltage()

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Remove support for optional supplies in the bulk API

The patch was based on my missinterpretation of the API and only
accidentally worked for me. Let's clean it out to not confuse others.

This reverts commit 3ff3f518a135fa4592fe2817e9ac2cce1fa23dc2.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Remove regulator_can_change_voltage()

There is little obvious use case for a regualtor driver to know if it is
possible to vary voltages at all by itself. If a consumer needs to
limit what voltages it tries to set based on the system configuration
then it will need to enumerate the possible voltages, and without that
even if it is possible to change voltages that doesn't mean that
constraints or other consumers will allow whatever change the driver is
trying to do at a given time. It doesn't even indicate if _set_voltage()
calls will work as noop _set_voltage() calls return success.

There were no users of this API that weren't abusing it and now they're
all gone so remove the API.

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

regulator: core: Add early supply resolution for regulators

The call to set_machine_constraints() in regulator_register(), will
attempt to get the voltage for the regulator. If a regulator is in
bypass will fail to get the voltage (ie. it's bypass voltage) and
hence register the regulator, because the supply for the regulator has
not been resolved yet.

To fix this, add a call to regulator_resolve_supply() before we call
set_machine_constraints(). If the call to regulator_resolve_supply()
fails, rather than returning an error at this point, allow the
registration of the regulator to continue because for some regulators
resolving the supply at this point may not be necessary and it will be
resolved later as more regulators are added. Furthermore, if the supply
is still not resolved for a bypassed regulator, this will be detected
when we attempt to get the voltage for the regulator and an error will
be propagated at this point.

If a bypassed regulator does not have a supply when we attempt to get
the voltage, rather than returing -EINVAL, return -EPROBE_DEFER instead
to allow the registration of the regulator to be deferred and tried
again later.

Please note that regulator_resolve_supply() will call
regulator_dev_lookup() which may acquire the regulator_list_mutex. To
avoid any deadlocks we cannot hold the regulator_list_mutex when calling
regulator_resolve_supply(). Therefore, rather than holding the lock
around a large portion of the registration code, just hold the lock when
aquiring any GPIOs and setting up supplies because these sections may
add entries to the regulator_map_list and regulator_ena_gpio_list,
respectively.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: refactor valid_ops_mask checking code

To make the code more compat and centralized, this patch add a
unified function - regulator_ops_is_valid. So we can add
some extra checking code easily later.

Signed-off-by: WEN Pingbo <pingbo.wen@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Move registration of regulator device

The public functions to acquire a regulator, such as regulator_get(),
internally look-up the regulator from the list of regulators that have
been registered with the regulator device class. The registration of
a new regulator with the regulator device class happens before the
regulator has been completely setup. Therefore, it is possible that
the regulator could be acquired before it has been setup successfully.
To avoid this move the device registration of the regulator to the end
of the regulator setup and update the error exit path accordingly.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Clear the supply pointer if enabling fails

During the resolution of a regulator's supply, we may attempt to enable
the supply if the regulator itself is already enabled. If enabling the
supply fails, then we will call _regulator_put() for the supply.
However, the pointer to the supply has not been cleared for the
regulator and this will cause a crash if we then unregister the
regulator and attempt to call regulator_put() a second time for the
supply. Fix this by clearing the supply pointer if enabling the supply
after fails when resolving the supply for a regulator.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Don't terminate supply resolution early

The function regulator_register_resolve_supply() is called from the
context of class_for_each_dev() (during the regulator registration) to
resolve any supplies added. regulator_register_resolve_supply() will
return an error if a regulator's supply cannot be resolved and this will
terminate the loop in class_for_each_dev(). This means that we will not
attempt to resolve any other supplies after one has failed. Hence, this
may delay the resolution of other regulator supplies until the failing
one itself can be resolved.

Rather than terminating the loop early, don't return an error code and
keep attempting to resolve any other supplies for regulators that have
been registered.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add debugfs to show constraint flags

There are debugfs entries for voltage and current, but not for
the constraint flags. It's useful for debugging to be able to
see what these flags are so this patch adds a new debugfs file.
We can't use debugfs_create_bool for this because the flags are
bitfields, so as this needs a special read callback they have been
collected into a single file that lists all the flags.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: remove lockdep assert from suspend_prepare

suspend_prepare can be called during regulator init time also, where
the mutex is not locked yet. This causes a false lockdep warning.
To avoid the problem, remove the lockdep assertion from the function
causing the issue. An alternative would be to lock the mutex during
init, but this would cause other problems (some APIs used during init
will attempt to lock the mutex also, causing deadlock.)

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix locking of GPIO list on free

When we acquire a shareable enable GPIO on probe we do so with the
regulator_list_mutex held. However when we release the GPIOs we do this
immediately after dropping the mutex meaning that the list could become
corrupted. Move the release into the locked region to avoid this.

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

regulator: reorder initialization steps in regulator_register()

device_register() is calling ->get_voltage() as part of it's sysfs attribute
initialization process, and this functions might need to know the regulator
constraints to return a valid value.
This is at least true for the pwm regulator driver (when operating in
continuous mode) which needs to know the minimum and maximum voltage values
to calculate the current voltage:

min_uV + (((max_uV - min_uV) * dutycycle) / 100);

Move device_register() after set_machine_constraints() to make sure those
constraints are correctly initialized when ->get_voltage() is called.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Stephen Barber <smbarber@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Use parent voltage from the supply when bypassed

When a regulator is in bypass mode it is functioning as a switch
returning the voltage set in the regulator will not give the voltage
being output by the regulator as it's just passing through its supply.
This means that when we are getting the voltage from a regulator we
should check to see if it is in bypass mode and if it is we should
report the voltage from the supply rather than that which is set on the
regulator.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
[treding@nvidia.com: return early for bypass mode]
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Fix deadlock during regulator registration

Commit 5e3ca2b349b1 ("regulator: Try to resolve regulators supplies on
registration") added a call to regulator_resolve_supply() within
regulator_register() where the regulator_list_mutex is held. This causes
a deadlock to occur on the Tegra114 Dalmore board when the palmas PMIC
is registered because regulator_register_resolve_supply() calls
regulator_dev_lookup() which may try to acquire the regulator_list_mutex
again.

Fix this by releasing the mutex before calling
regulator_register_resolve_supply() and update the error exit path to
ensure the mutex is released on an error.

[Made commit message more legible -- broonie]

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Log when we bring constraints into range

This aids in debugging problems triggered by the regulator core applying
its constraints, we could potentially crash immediately after updating
the voltage if the constraints are buggy.

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

regulator: Try to resolve regulators supplies on registration

Commit 6261b06de565 ("regulator: Defer lookup of supply to regulator_get")
moved the regulator supplies lookup logic from the regulators registration
to the regulators get time.

Unfortunately, that changed the behavior of the regulator core since now a
parent supply with a child regulator marked as always-on, won't be enabled
unless a client driver attempts to get the child regulator during boot.

This patch tries to resolve the parent supply for the already registered
regulators each time that a new regulator is registered. So the regulators
that have child regulators marked as always on will be enabled regardless
if a driver gets the child regulator or not.

That was the behavior before the mentioned commit, since parent supplies
were looked up at regulator registration time instead of during child get.

Since regulator_resolve_supply() checks for rdev->supply, most of the times
it will be a no-op. Errors aren't checked to keep the possible out of order
dependencies which was the motivation for the mentioned commit.

Also, the supply being available will be enforced on regulator get anyways
in case the resolve fails on regulators registration.

Fixes: 6261b06de565 ("regulator: Defer lookup of supply to regulator_get")
Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: <stable@vger.kernel.org> # 4.1+

regulator: core: Ensure we are at least in bounds for our constraints

Currently we only attempt to set the voltage during constraints
application if an exact voltage is specified. Extend this so that if
the currently set voltage for the regulator is outside the bounds set in
constraints we will move the voltage to the nearest constraint, raising
to the minimum or lowering to the maximum as needed. This ensures that
drivers can probe without the hardware being driven out of spec.

Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Remove duplicate copy of active-discharge parsing

Apparently due to a wrongly resolved merge conflict between two
branches, which contained the same commit, the commit contents
partially was added two times in a row.

This change reverts the latter wrong inclusion of commit 909f7ee0b5f3
("regulator: core: Add support for active-discharge configuration").

The first applied commit 670666b9e0af ("regulator: core: Add support
for active-discharge configuration") is not touched.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Remove unneded check for regulator supply

The regulator_resolve_supply() function checks if a supply has been
associated with a regulator to avoid enabling it if that is not the
case.

But the supply was already looked up with regulator_resolve_supply()
and set with set_supply() before the check and both return on error.

So the fact that this statement has been reached means that neither
of them failed and a supply must be associated with the regulator.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add support for active-discharge configuration

Add support to enable/disable active discharge of regulator via
machine constraints. This configuration is done when setting
machine constraint during regulator register and if regulator
driver implemented the callback ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Add support for active-discharge configuration

Add support to enable/disable active discharge of regulator via
machine constraints. This configuration is done when setting
machine constraint during regulator register and if regulator
driver implemented the callback ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix crash in error path of regulator_register

This problem was introduced by:
commit daad134d6649 ("regulator: core: Request GPIO before creating
sysfs entries")

The error path was not updated correctly after moving GPIO registration
code and in case regulator_ena_gpio_free failed, device_unregister() was
called even though device_register() was not yet called.

This problem breaks the boot at least on all Tegra 32-bit devices. It
will also crash each device that specifices GPIO that is unavaiable at
regulator_register call. Here's error log I've got when forced GPIO to
be invalid:

[ 1.116612] usb-otg-vbus-reg: Failed to request enable GPIO10: -22
[ 1.122794] Unable to handle kernel NULL pointer dereference at
virtual address 00000044
[ 1.130894] pgd = c0004000
[ 1.133598] [00000044] *pgd=00000000
[ 1.137205] Internal error: Oops: 5 [#1] SMP ARM

and here's backtrace from KDB:

Exception stack(0xef11fbd0 to 0xef11fc18)
fbc0: 00000000 c0738a14 00000000 00000000
fbe0: c0b2a0b0 00000000 00000000 c0738a14 c0b5fdf8 00000001 ef7f6074 ef11fc4c
fc00: ef11fc50 ef11fc20 c02a8344 c02a7f1c 60000013 ffffffff
[<c010cee0>] (__dabt_svc) from [<c02a7f1c>] (kernfs_find_ns+0x18/0xf8)
[<c02a7f1c>] (kernfs_find_ns) from [<c02a8344>] (kernfs_find_and_get_ns+0x40/0x58)
[<c02a8344>] (kernfs_find_and_get_ns) from [<c02ac4a4>] (sysfs_unmerge_group+0x28/0x68)
[<c02ac4a4>] (sysfs_unmerge_group) from [<c044389c>] (dpm_sysfs_remove+0x30/0x5c)
[<c044389c>] (dpm_sysfs_remove) from [<c0436ba8>] (device_del+0x48/0x1f4)
[<c0436ba8>] (device_del) from [<c0436d84>] (device_unregister+0x30/0x6c)
[<c0436d84>] (device_unregister) from [<c0403910>] (regulator_register+0x6d0/0xdac)
[<c0403910>] (regulator_register) from [<c04052d4>] (devm_regulator_register+0x50/0x84)
[<c04052d4>] (devm_regulator_register) from [<c0406298>] (reg_fixed_voltage_probe+0x25c/0x3c0)
[<c0406298>] (reg_fixed_voltage_probe) from [<c043d21c>] (platform_drv_probe+0x60/0xb0)
[<c043d21c>] (platform_drv_probe) from [<c043b078>] (driver_probe_device+0x24c/0x440)
[<c043b078>] (driver_probe_device) from [<c043b5e8>] (__device_attach_driver+0xc0/0x120)
[<c043b5e8>] (__device_attach_driver) from [<c043901c>] (bus_for_each_drv+0x6c/0x98)
[<c043901c>] (bus_for_each_drv) from [<c043ad20>] (__device_attach+0xac/0x138)
[<c043ad20>] (__device_attach) from [<c043b664>] (device_initial_probe+0x1c/0x20)
[<c043b664>] (device_initial_probe) from [<c043a074>] (bus_probe_device+0x94/0x9c)
[<c043a074>] (bus_probe_device) from [<c043a610>] (deferred_probe_work_func+0x80/0xcc)
[<c043a610>] (deferred_probe_work_func) from [<c01381d0>] (process_one_work+0x158/0x454)
[<c01381d0>] (process_one_work) from [<c013854c>] (worker_thread+0x38/0x510)
[<c013854c>] (worker_thread) from [<c013e154>] (kthread+0xe8/0x104)
[<c013e154>] (kthread) from [<c0108638>] (ret_from_fork+0x14/0x3c)

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@tieto.com>
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Request GPIO before creating sysfs entries

regulator_attr_is_visible (which is a .is_visible callback of
regulator_dev_group attribute_grpup) checks rdev->ena_pin to decide if
"status" file should be present in sysfs. This field is set at the end
of regulator_ena_gpio_request so it has to be called before
device_register() otherwise this test will always fail, causing "status"
file to not be visible.

Since regulator_attr_is_visible also tests for is_enabled() op, this
problem is only visible for regulators that does not define this
callback, like regulator-fixed.c.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@tieto.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Rely on regulator_dev_release to free constraints

As we now free the constraints in regulator_dev_release we will still
call free on the constraints pointer even if we went down an error
path in regulator_register, because it is only allocated after the
device_register. As such we no longer need to free rdev->constraints
on the error paths, so this patch removes said frees.

Fixes: 29f5f4860a8e ("regulator: core: Move more deallocation into class unregister")
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: remove some dead code

Originally queue_delayed_work() used to negative error codes or 0 and 1
on success depending if the work was queued or not. It caused a lot of
bugs where people treated all non-zero returns as failures so we changed
it to return bool instead in d4283e937861 ('workqueue: make queueing
functions return bool'). Now it never returns failure.

Checking for negative values causes a static checker warning since it is
impossible based on the bool type.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: use dev_to_rdev

Use dev_to_rdev() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Fix nested locking of supplies

Commit fa731ac7ea04 ("regulator: core: avoid unused variable warning")
introduced a subtle change in how supplies are locked. Where previously
code was always locking the regulator of the current iteration, the new
implementation only locks the regulator if it has a supply. For any
given power tree that means that the root will never get locked.

On the other hand the regulator_unlock_supply() will still release all
the locks, which in turn causes the lock debugging code to warn about a
mutex being unlocked which wasn't locked.

Cc: Mark Brown <broonie@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Fixes: Fixes: fa731ac7ea04 ("regulator: core: avoid unused variable warning")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Ensure we lock all regulators

The latest workaround for the lockdep interface's not using the second
argument of mutex_lock_nested() changed the loop missed locking the last
regulator due to a thinko with the loop termination condition exiting
one regulator too soon.

Reported-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: fix regulator_lock_supply regression

As noticed by Geert Uytterhoeven, my patch to avoid a harmless build warning
in regulator_lock_supply() was total crap and introduced a real bug:

> [ BUG: bad unlock balance detected! ]
> kworker/u4:0/6 is trying to release lock (&rdev->mutex) at:
> [<c0247b84>] regulator_set_voltage+0x38/0x50

we still lock the regulator supplies, but not the actual regulators,
so we are missing a lock, and the unlock is unbalanced.

This rectifies it by first locking the regulator device itself before
using the same loop as before to lock its supplies.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 716fec9d1965 ("[SUBMITTED] regulator: core: avoid unused variable warning")
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: avoid unused variable warning

The second argument of the mutex_lock_nested() helper is only
evaluated if CONFIG_DEBUG_LOCK_ALLOC is set. Otherwise we
get this build warning for the new regulator_lock_supply
function:

drivers/regulator/core.c: In function 'regulator_lock_supply':
drivers/regulator/core.c:142:6: warning: unused variable 'i' [-Wunused-variable]

To avoid the warning, this restructures the code to make it
both simpler and to move the 'i++' outside of the mutex_lock_nested
call, where it is now always used and the variable is not
flagged as unused.

We had some discussion about changing mutex_lock_nested to an
inline function, which would make the code do the right thing here,
but in the end decided against it, in order to guarantee that
mutex_lock_nested() does not introduced overhead without
CONFIG_DEBUG_LOCK_ALLOC.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 9f01cd4a915 ("regulator: core: introduce function to lock regulators and its supplies")
Link: http://permalink.gmane.org/gmane.linux.kernel/2068900
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Make bulk API support optional supplies

Make it possible to use the bulk API with optional supplies, by allowing
the consumer to marking supplies as optional in the regulator_bulk_data.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: Use regulator_lock_supply() for get_voltage() too

Since we need to read voltages of parents as part of setting supply
voltages we need to be able to do get_voltage() internally without
taking locks so reorganize the locking to take locks on the full tree on
entry rather than as we recurse when called externally.

Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Propagate voltage changes to supply regulators

Until now changing the voltage of a regulator only ever effected the
regulator itself, but never its supplies. It's a common pattern though
to put LDO regulators behind switching regulators. The switching
regulators efficiently drop the input voltage but have a high ripple on
their output. The output is then cleaned up by the LDOs. For higher
energy efficiency the voltage drop at the LDOs should be minimized. For
this scenario we need to propagate the voltage change to the supply
regulators. Another scenario where voltage propagation is desired is
a regulator which only consists of a switch and thus cannot regulate
voltages itself. In this case we can pass setting voltages to the
supply.

This patch adds support for voltage propagation. We do voltage
propagation when the current regulator has a minimum dropout voltage
specified or if the current regulator lacks a get_voltage operation
(indicating it's a switch and not a regulator).

Changing the supply voltage must be done carefully. When we are
increasing the current regulators output we must first increase the
supply voltage and then the regulator itself. When we are decreasing the
current regulators voltage we must decrease the supply voltage after
changing the current regulators voltage.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: Factor out regulator_map_voltage

_regulator_call_set_voltage has code to translate a minimum/maximum
voltage pair into a selector. This code is useful for others aswell,
so create a regulator_map_voltage function.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: create unlocked version of regulator_set_voltage

The unlocked version will be needed when we start propagating voltage
changes to the supply regulators.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regulator: core: create unlocked version of regulator_list_voltage

The unlocked version will be needed when we start propagating voltage
changes to the supply regulators.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>