This patch adds a regulator driver for the MCP16502 PMIC.
This drivers supports basic operations through the
regulator interface such as:
- setting/reading voltage
- setting/reading operating mode
- reading current status
Signed-off-by: Andrei Stefanescu <andrei.stefanescu@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Implement shutdown method to make sure the PMIC will not enter the suspend
state when the system is shutdown.
This work is based on work done by Borris Brezillon on [1].
[1] https://www.spinics.net/lists/kernel/msg2942960.html
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix line over 80 chars checkpatch.pl warning.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The regulator supports a dedicated suspend mode.
Implement the appropriate ->set_suspend_xx() hooks, add support for
->set_mode(), and provide basic PM ops functionalities to setup the
regulator in a suspend state when the system is entering suspend.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
[claudiu.beznea@microchip.com: remove shutdown function, use dev_pm_ops,
fix checkpatch warning, adapt commit message, add LDO modes support,
move modes constants to active-semi,8945a-regulator.h, remove rdevs from
struct act8945a_pmic, add op_mode to act8945a_pmic]
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Unlock expert registers for act8945a.
This is based on orginal work of Boris Brezillon at [1].
[1] https://www.spinics.net/lists/kernel/msg2942960.html
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
After making sure that the regulator core always take over
handling of the GPIO descriptors, the gpiod_put()
on the errorpath of the Arizona LDO1 driver becomes
redundant.
Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
After making sure that the regulator core always take over
handling of the GPIO descriptors, the gpiod_put()
on the errorpath of the wm8994 driver becomes redundant.
Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
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>
The GPIO descriptors used by the S2MPS11 driver are retrieved
during probe() and it is really helpful to have those under
devres management because of all the errorpaths in the
intialization.
Using the new dev_gpiod_unhinge() call we can remove the
devres management of the descriptor right before handing
it over to the regulators core.
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>
The GPIO descriptors used by the TPS65090 driver are retrieved
during probe() and it is really helpful to have those under
devres management because of all the errorpaths in the
intialization.
Using the new dev_gpiod_unhinge() call we can remove the
devres management of the descriptor right before handing
it over to the regulators core.
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>
The GPIO descriptors used by the S5M8767 driver are retrieved
during probe() and it is really helpful to have those under
devres management because of all the errorpaths in the
intialization.
Using the new dev_gpiod_unhinge() call we can remove the
devres management of the descriptor right before handing
it over to the regulators core.
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>
The GPIO descriptors used by the DA9211 driver are retrieved
during probe() and it is really helpful to have those under
devres management because of all the errorpaths in the
intialization.
Using the new dev_gpiod_unhinge() call we can remove the
devres management of the descriptor right before handing
it over to the regulators core.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The probe path of this driver is a bit complex: sometimes the
GPIO descriptor is passed to the regulator core, sometimes
it is not.
To handle it in a simple way: stick with the devm_* resource
management and unhinge the GPIO descriptor devres handling
right before passing it to the regulator core, if we pass it
to the regulator core.
Fixes: e7d2be696f ("regulator: max8973: Pass descriptor instead of GPIO number")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the gpiod_get_from_of_node() rather than the devm_*
version so that the regulator core can handle the lifecycle
of these descriptors.
Fix up the errorpath so that we free this descriptor if
an error occurs in the callback. Rely on the regulator
core to deal with it after this point: a previous patch
fixed up the regulator core to properly dispose any
GPIO descriptors once you call regulator_register().
Fixes: 96392c3d8c ("regulator: max77686: Pass descriptor instead of GPIO number")
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>
Use the gpiod_get() rather than the devm_* version so that the
regulator core can handle the lifecycle of these descriptors.
Fixes: d7a261c2d1 ("regulator: max8952: Pass descriptor instead of GPIO number")
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>
Use the gpiod_get() rather than the devm_* version so that the
regulator core can handle the lifecycle of these descriptors.
Fixes: 2468f0d515 ("regulator: lp8788-ldo: Pass descriptor instead of GPIO number")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the gpiod_get() rather than the devm_* version so that the
regulator core can handle the lifecycle of these descriptors.
Fixes: b2d751b7f6 ("regulator: lm363x: Pass descriptor instead of GPIO number")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Use the gpiod_get() rather than the devm_* version so that the
regulator core can handle the lifecycle of these descriptors.
Fixes: efdfeb079c ("regulator: fixed: Convert to use GPIO descriptor only")
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>
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>
Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.
For instances using of_node_cmp, this has the side effect of now using
case sensitive comparisons. This should not matter for any FDT based
system which all of these are.
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Support Opensource <support.opensource@diasemi.com>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently it is expected that regulator init data will be defined as a
series of sub-nodes from the node that bound in the driver. Add support
for a node to both bind in a driver and contain init data for that
regulator.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
To support future additions factor out the location of the OF node
containing the init data for the regulator from the code that parses the
init data.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The AXP20X driver currently has several masks defined throughout the
code. Use nice defines to make them clean and more descriptive.
Additionally include bitops.h, which was missing before, and sort
headers.
Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Priit Laes <plaes@plaes.org>
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>
The regulator core takes over managing the lifetime of the enable GPIO
once the regulator is registered. As such we shouldn't register the
enable GPIO using devm, or it will be freed twice.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.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>
Based on review comments on the MFD driver, move the child drivers for
the Lochnagar MFD over to binding through device tree.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
GPIO descriptor array must be zero initialized to ensure that core will
properly handle also the case when no external GPIO pin is defined.
Fixes: 1c984942f0 ("regulator: s2mps11: Pass descriptor instead of GPIO number")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
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>
Instead of passing a global GPIO number, pass a descriptor looked
up from the device tree configuration node.
Tested on Odroid U3 (with max77686 although not using any GPIOs
for regulators, so at least default paths are not broken).
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Instead of passing a global GPIO number for the enable GPIO, pass
a descriptor looked up from the device tree node or the board file
decriptor table for the regulator.
There is a single board file passing the GPIOs for LDO1 and LDO2
through platform data, so augment this to pass descriptors
associated with the i2c device as well.
The special GPIO enable DT property for the enable GPIO is
nonstandard but this was accomodated in
commit 6a537d4846
"gpio: of: Support regulator nonstandard GPIO properties".
Cc: patches@opensource.cirrus.com
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Instead of passing a global GPIO number for the enable GPIO, pass
a descriptor looked up with the standard devm_gpiod_get_optional()
call.
This regulator supports passing platform data, but enable/sleep
regulators are looked up from the device tree exclusively, so
we can need not touch other files.
Tested on Odroid XU3 (with s2mps11 although not using any GPIOs
for regulators, so at least default paths are not broken).
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
BD71837 and BD71847 have a HW functionality which leave power
rails OFF after powerof state:
- if they have been controlled by SW.
- if state transition from poweroff is done to SNVS
BD71837 can after reset transition from power-off to SNVS or
READY state depending on reset reason. By default only wathcdog
reset changes state from poweroff to ready. Change PMIC
configuration to always transition to READY in order to avoid
crucial power rails being OFF after reset.
If SNVS is required the crucial power rails should not be
controlled by SW - eg corresponding regulator control register
should have SEL bit kept zero. Currently the driver assumes all
regulators to be controlled by SW so it sets all SEL bits to 1.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch updates license to use SPDX-License-Identifier
instead of verbose license text.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch updates license to use SPDX-License-Identifier
instead of verbose license text.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The voltages in bd718xx_3rd_nodvs_buck_volts are in ascendant order, so use
regulator_map_voltage_ascend.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Set the according constraints for PM_SUSPEND_STANDBY case.
Previously, only suspend to mem/disk were taken into
consideration.
Signed-off-by: Andrei Stefanescu <andrei.stefanescu@microchip.com>
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>
