To support shared enable GPIO pin, replace GPIO code with new static functions

 Reference count: 'enable_count'
   Balance the reference count of each GPIO and actual pin control.
   The count is incremented with enabling GPIO.
   On the other hand, it is decremented on disabling GPIO.
   Actual GPIO pin is enabled at the initial use.(enable_count = 0)
   The pin is disabled if it is not used(shared) any more. (enable_count <=1)
   Regardless of the enable count, update GPIO state of the regulator.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Reviewed-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

 A Regulator can be enabled by external GPIO pin.
 This is configurable in the regulator_config.
 At this moment, the GPIO can be owned by only one regulator device.
 In some devices, multiple regulators are enabled by shared one GPIO pin.
 This patch extends this limitation, enabling shared enable GPIO of regulators.

 New list for enable GPIO: 'regulator_ena_gpio_list'
   This manages enable GPIO list.

 New structure for supporting shared enable GPIO: 'regulator_enable_gpio'
   The enable count is used for balancing GPIO control count.
   This count is incremented when GPIO is enabled.
   On the other hand, it's decremented when GPIO is disabled.

 Reference count: 'request_count'
   The reference count, 'request_count' is incremented/decremented on
   requesting/freeing the GPIO. This count makes sure only free the GPIO
   when it has no users.

 How it works
   If the GPIO is already used, skip requesting new GPIO usage.
   The GPIO is new one, request GPIO function and add it to the list of
   enable GPIO.
   This list is used for balancing enable GPIO count and pin control.

 Updating a GPIO and invert code moved
   'ena_gpio' and 'ena_gpio_invert' of the regulator_config were moved to
    new function, regulator_ena_gpio_request().
    Use regulator_enable_pin structure rather than regulator_dev.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Reviewed-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

commit dd8004af: 'regulator: core: Log when a device causes a voltage
constraint fail', tried to print out some information about the
check consumer min/max uV fixup, however, it uses a garbage pointer
left over from list_for_each_entry leading to boot messages in the
form:

'[    2.079890] <RANDOM ASCII>: Restricting voltage, 3735899821-4294967295uV'

Because it references regulator->dev, it could potentially read memory from
anywhere causing a panic.

This patch instead uses rdev and the updated min/max uV values.
Signed-off-by: NRuss Dill <Russ.Dill@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Optimize _regulator_do_set_voltage() for the case selector is equal to
old_selector. Since the voltage does not change, we don't need to call
set_voltage_sel() and set_voltage_time_sel() in this case.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

regulator_register() does not return 0 on success, fix the comment.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some DVM regulators needs to update apply_bit after setting vsel_reg to
initiate voltage change on the output.  This patch adds apply_reg and
apply_bit to struct regulator_desc and update
regulator_set_voltage_sel_regmap() to set apply_bit of apply_reg when
apply_bit is set.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Regulator drivers with continuous_voltage_range flag set allows not setting
n_voltages. Thus if continuous_voltage_range is set, check the constraint range
instead.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NPaolo Pisati <paolo.pisati@canonical.com>
Tested-by: NRobert Nelson <robertcnelson@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Having a linear_min_sel setting means the first linear_min_sel selectors are
invalid. We need to subtract linear_min_sel when use n_voltages to determinate
if regulator can change voltage.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Introduce a regulator_can_change_voltage() function for the subsytems or
drivers which might check if applying voltage change is possible and use
special workaround code when the driver is used with fixed regulators or
regulators with disabled ability to change the voltage.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Helps with figuring out when things went wrong.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some drivers (at least 3 drivers) have such variant of linear mapping that
the first few selectors are invalid and the reset are linear mapping.
Let's support this case in core.

This patch adds linear_min_sel in struct regulator_desc,
so we can allow specific minimal selector for starting linear mapping.
Then extends regulator_[map|list]_voltage_linear() to support this feature.

Note that for selectors less than min_linear_index, we need count them to
n_voltages so regulator_list_voltage() won't fail while checking the boundary
for selector before calling list_voltage callback.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

regulator_is_supported_voltage() should return true only if the voltage
of fixed/constant regulator is between min_uV and max_uV.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

When regulator_register fails and exits through the scrub path the
regulator_put function was called whilst holding the
regulator_list_mutex, causing deadlock.

This patch adds a private version of the regulator_put function which
can be safely called whilst holding the mutex, replacing the
aforementioned call.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If the gpio_request_one() fails, or returns EPROBE_DEFER, the
regulator must be device_unregister()ed. When this is not done,
there are WARNING: from sysfs:

WARNING: at fs/sysfs/file.c:343 sysfs_open_file+0x238/0x268()
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some regulators can set any voltage within the constraints range,
not being limited to specified operating points.

This patch makes it possible to describe such regulator and makes
the regulator_is_supported_voltage() function behave correctly.
Signed-off-by: NPawel Moll <pawel.moll@arm.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Many regulators support a bypass mode where they simply switch their
input supply to the output. This is mainly used in low power retention
states where power consumption is extremely low so higher voltage or
less clean supplies can be used.

Support this by providing ops for the drivers and a consumer API which
allows the device to be put into bypass mode if all consumers enable it
and the machine enables permission for this.

This is not supported as a mode since the existing modes are rarely used
due to fuzzy definition and mostly redundant with modern hardware which is
able to respond promptly to load changes.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NGraeme Gregory <gg@slimlogic.co.uk>

If the device doesn't have a regmap specified by the driver and we can't
find one on the device itself try its parent, providing a useful defualt
for many MFDs.

[Rewrite commit message -- broonie]
Signed-off-by: NAnilKumar Ch <anilkumar@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Users (especially framework code) may end up passing in a zero deferral
time depending on runtime conditions or configuration. If they do then
just call regulator_disable() directly to save scheduling.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

If a regulator only supports a single voltage list_voltage() can be used
to report what that voltage is so add this as one of the criteria for
creating the microvolts file in sysfs.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Fix regulator kernel-doc warnings:

Warning(drivers/regulator/core.c:2308): No description found for parameter 'rdev'
Warning(drivers/regulator/core.c:2308): Excess function parameter 'regulator' description in 'regulator_set_voltage_time_sel'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc:	Liam Girdwood <lrg@ti.com>
Cc:	Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com> 

Fix regulator kernel-doc warnings:

Warning(drivers/regulator/core.c:2308): No description found for parameter 'rdev'
Warning(drivers/regulator/core.c:2308): Excess function parameter 'regulator' description in 'regulator_set_voltage_time_sel'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Cc:	Liam Girdwood <lrg@ti.com>
Cc:	Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Commit 65f73508 ("regulator: core: Add core support for GPIO controlled
enable lines") introduced enable gpio entry in regulator configuration
structure. Some drivers use '-1' as a placeholder for marking that such
gpio line is not available, because '0' is considered as a valid gpio
number. This patch fixes initialization of such drivers (like MAX8952
on UniversalC210 board), when '-1' is provided as enable gpio pin in the
regulator's platform data.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If the regulator doesn't supply a way of reading back the voltage but does
provide a list_voltage() operation then use that with a selector of zero
to read the voltage.  Regulators doing this means that we have the list
operation there for consumers that want to configure themselves.
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This prevents the output of just

	dummy:

in the boot log. Now it says:

	regulator-dummy: no parameters

which at least doesn't make it look like an accidental printk and also doesn't
only use "dummy" which could mean anything.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This is to address the following warning during compilation time: (Compile on x86_64)

  CC      drivers/regulator/core.o
drivers/regulator/core.c: In function '_regulator_do_set_voltage':
drivers/regulator/core.c:2183:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

This patch adds a temporary variable to avoid double cast.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When registering the regulator and setting supply for the regulator
then increment open_count to reflect correct number of users.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This is in preparation for teaching async_synchronize_full() to sync all
pending async work, and not just on the async_running domain.  This
conversion is functionally equivalent, just embedding the existing list
in a new async_domain type.

The .registered attribute is used in a later patch to distinguish
between domains that want to be flushed by async_synchronize_full()
versus those that only expect async_synchronize_{full|cookie}_domain to
be used for flushing.

[jejb: add async.h to scsi_priv.h for struct async_domain]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

REGULATOR_STATUS_UNDEFINED is to be returned by regulator, if any other state
doesn't really apply.
Signed-off-by: NKrystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Case REGULATOR_STATUS_STANDBY -> REGULATOR_MODE_STANDBY.
Signed-off-by: NKrystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Since DT doesn't provide an idiomatic mechanism for enabling full
constraints and since it's much more natural with DT to provide them
just assume that a DT enabled system has full constraints.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLiam Girdwood <lrg@ti.com>

With changes introduced by commit 222cc7b1 (regulator: core: Allow
multiple requests of a single supply mapping) on create_regulator,
regulator_put needs a corresponding update on sysfs entry removing.

Also regulator->dev still needs to get assigned in create_regulator,
otherwise, sysfs_remove_link call in regulator_put will get bypassed.
Reported-by: NFabio Estevam <festevam@gmail.com>
Tested-by: NDong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It is very common for regulators to support having their enable signal
controlled by a GPIO. Since there are a bunch of fiddly things to get
right like handling the operations when the enable signal is tied to
a rail and it's just replicated code add support for this to the core.

Drivers should set ena_gpio in their config if they have a GPIO control,
using ena_gpio_flags to specify any flags (including GPIOF_OUT_INIT_ for
the initial state) and ena_gpio_invert if the GPIO is active low. The
core will then override any enable and disable operations the driver has
and instead control the specified GPIO.

This will in the future also allow us to further extend the core by
identifying when several enable signals have been tied together and
handling this properly.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Create new _regulator_do_enable() and _regulator_do_disable() operations
which deal with the mechanics of performing the enable and disable, partly
to cut down on the levels of indentation and partly to support some future
work.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Many regulators have a fixed specification for their enable time. Allow
this to be set in the regulator_desc as a number to save them having to
implement an explicit operation.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Lots of regulator drivers have checks in their map_voltage() functions
to verify that the result of the mapping is in the range originally
specified. Factor these out in the core and provide a bit of extra
defensiveness for other drivers by doing the check in the core.

Since we're now doing a list_voltage() earlier move the current mapping
back to a voltage out into the set_voltage() call to save redoing it.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>