- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with other
trees, unfortunately. He has a lot more of these waiting on the wings
that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos, and one
on Spectre vulnerabilities.
- Various improvements to the build system, including automatic markup of
function() references because some people, for reasons I will never
understand, were of the opinion that :c:func:``function()`` is
unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
"It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with
other trees, unfortunately. He has a lot more of these waiting on
the wings that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos,
and one on Spectre vulnerabilities.
- Various improvements to the build system, including automatic
markup of function() references because some people, for reasons I
will never understand, were of the opinion that
:c:func:``function()`` is unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc"
* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
docs: automarkup.py: ignore exceptions when seeking for xrefs
docs: Move binderfs to admin-guide
Disable Sphinx SmartyPants in HTML output
doc: RCU callback locks need only _bh, not necessarily _irq
docs: format kernel-parameters -- as code
Doc : doc-guide : Fix a typo
platform: x86: get rid of a non-existent document
Add the RCU docs to the core-api manual
Documentation: RCU: Add TOC tree hooks
Documentation: RCU: Rename txt files to rst
Documentation: RCU: Convert RCU UP systems to reST
Documentation: RCU: Convert RCU linked list to reST
Documentation: RCU: Convert RCU basic concepts to reST
docs: filesystems: Remove uneeded .rst extension on toctables
scripts/sphinx-pre-install: fix out-of-tree build
docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
Documentation: PGP: update for newer HW devices
Documentation: Add section about CPU vulnerabilities for Spectre
Documentation: platform: Delete x86-laptop-drivers.txt
docs: Note that :c:func: should no longer be used
...
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>
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>
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>
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>
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>
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>
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>
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>
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: 541d052d72 ("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>
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: f8702f9e4a ("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>
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: 9243a195be ("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>
[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 e5e21f70bf ("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: e5e21f70bf ("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>
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
8a34e979f6 ("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>
commit e5e21f70bf ("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: e5e21f70bf ("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>
This is a remnant of commit 70a7fb80e8 ("regulator: core: Fix nested
locking of supplies").
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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>
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>
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>
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>
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>
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 1fc12b0589 ("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 1fc12b0589 ("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: 1fc12b0589 ("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>
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>
Prior to commit 5451781dad ("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: 5451781dad ("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>
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>
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 f8702f9e4a ("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>
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>
In the commit f8702f9e4a ("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: f8702f9e4a ("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>
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>
This fixes compiling regulator drivers that use these function when
these drivers are built as kernel modules.
Fixes: f8702f9e4a ("regulator: core: Use ww_mutex for regulators locking")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Linus Torvalds
zoro