Many regulator drivers implement voltage setting by looping through a
table of possible values, normally because the set of available voltages
can't be mapped onto selectors with simple calcuation. Factor out these
loops by providing a variant of set_voltage() which takes a selector rather
than a voltage range as an argument and implementing a loop through the
available selectors in the core.

This is not going to be suitable for use with all devices as when the
regulator voltage can be mapped onto selector values with a simple
calculation the linear scan through the available values will be more
expensive than just doing the calculation, especially for regulators
that provide fine grained voltage control.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Push all the callers of the chip set_voltage() operation out into a single
function to facilitiate future refactoring.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Since drivers already have to provide an API for translating selectors
into voltages they may as well just report the selector values directly
to the core API rather than implement the lookup themselves. The old
interface is left in place for now, but may be removed in future.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Rather than referencing the get_voltage() operation directly in the
ops struct use the internal _regulator_get_voltage() API call to do
so, facilitating refactoring.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Align arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Extend the regulator_set_voltage() function to take into account the
voltage requirements of all consumers of the regulator being changed,
in order to set the voltage to the minimum voltage acceptable to all
consumers. The existing behaviour was that the latest
regulator_set_voltage() call would win over previous
regulator_set_voltage() calls even if setting the voltage to a
non-acceptable level from other consumers.
Signed-off-by: NThomas Petazzoni <t-petazzoni@ti.com>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

On Tue, 2010-11-30 at 10:52 +0000, Mark Brown wrote:
> On Mon, Nov 29, 2010 at 05:12:56PM -0800, Joe Perches wrote:
> > Just to please broonie...
> > Signed-off-by: Joe Perches <joe@perches.com>
> As usual when fixing review issues please revise your original patch
> rather than posting a fresh patch.

Here's an earlier comment:

On Thu, 2010-11-18 at 13:30 +0000, Mark Brown wrote:
> This looks reasonable, please rebase on top of Daniel's patches and
> submit it properly (with changelog and so on).

Sometimes it's simpler for an upstream maintainer to do
something like:

git am -s <patch1.mbox>
patch -p1 < patch2.mbox
git commit --amend file

instead of back and forthing.
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Currently the regulator API uses the constraints structure passed in to
the core throughout the lifetime of the object. This means that it is not
possible to mark the constraints as __initdata so if the kernel supports
many boards the constraints for all of them are kept around throughout the
lifetime of the system, consuming memory needlessly. By copying constraints
that are actually used we allow the use of __initdata, saving memory when
multiple boards are supported.

This also means the constraints can be const.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

The version hasn't been updated since the regulator API was merged in
2.6.27 so just remove it - now we're in mainline the kernel version is
much more useful.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Don't use %s to format fixed static strings into log messages, it just
makes searching for and reading the message in the kernel source
needlessly hard.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

The regulator framework uses a lot of printks with a
specific formatting using __func__. This converts them
to use pr_ calls with a central format string.

Cc: bleong@codeaurora.org
Signed-off-by: NDaniel Walker <dwalker@codeaurora.org>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This adds a pr_fmt line which uses the __func__ macro. I also
convert the current pr_ lines to remove their __func__ usage.

Cc: bleong@codeaurora.org
Signed-off-by: NDaniel Walker <dwalker@codeaurora.org>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Supply regulators are disabled only when the last
reference count is removed on the child regulator
(the use count goes from 1 to 0). This patch changes
the behaviour of enable so the supply regulator is
enabled only when the use count of the child
regulator goes from 0 to 1.
Signed-off-by: NBengt Jonsson <bengt.g.jonsson@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Provide some basic trace facilities to the regulator API. We generate
events on regulator enable, disable and voltage setting over the actual
hardware operations (which are assumed to be the expensive ones which
require interaction with the actual device). This is intended to facilitate
debug of the performance and behaviour with consumers allowing unified
traces to be generated including the regulator operations within the
context of the other components of the system.

For enable we log the explicit delay for the voltage ramp separately to
the interaction with the hardware to highlight the time consumed in I/O.
We should add a similar delay for voltage changes, though there the
relatively small magnitude of the changes in the context of the I/O
costs makes it much less critical for most regulators.

Only hardware interactions are currently traced as the primary focus is
on the performance and synchronisation of actual hardware interactions.
Additional tracepoints for debugging of the logical operations can be
added later if required.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Change the interface used by set_voltage() to report the selected value
to the regulator core in terms of a selector used by list_voltage().
This allows the regulator core to know the voltage that was chosen
without having to do an explict get_voltage(), which would be much more
expensive as it will generally access hardware.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This patch add locks around regulator supply enable.
Signed-off-by: NMattias Wallin <mattias.wallin@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Fix kernel-doc warning for set_consumer_device_supply():

Warning(drivers/regulator/core.c:912): missing initial short description on line:
 * set_consumer_device_supply: Bind a regulator to a symbolic supply
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc:	Liam Girdwood <lrg@slimlogic.co.uk>
Cc:	Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Supply regulators are disabled only when the last
reference count is removed on the child regulator
(the use count goes from 1 to 0). This patch changes
the behaviour of enable so the supply regulator is
enabled only when the use count of the child
regulator goes from 0 to 1.
Signed-off-by: NBengt Jonsson <bengt.g.jonsson@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This patch add locks around regulator supply enable.
Signed-off-by: NMattias Wallin <mattias.wallin@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Integer division will truncate the result, this patch ensures we have
enough delay time for enabling regulator.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

We already have device_remove_file() in error path,
no need to call it before goto link_name_err.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This patch fixes a disable failure when regulator supply is used.
A while loop in regulator disable checks for supply pointer != NULL
but the pointer is not always updated, resulting in the while loop
running too many times causing a disable failure.
Signed-off-by: NMattias Wallin <mattias.wallin@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

I have a regulator A that sets regulator B as its supply. When I call
set_supply to add B as the supply for A, regulator A gets added to the
supply_list for regulator B.

When I call regulator_disable(A), I end up with a call chain like this:

regulator_disable(A)
> mutex_lock(A)
> _regulator_disable(A)
>> _regulator_disable(B)
>>> _notifier_call_chain(B)
>>>> mutex_lock(A)

Which results in dead lock since we are trying to acquire the mutex lock
for regulator A which we already hold.

This patch addresses this issue by moving the call to disable regulator
B outside of the lock aquired inside the initial call to
regulator_disable.

This change also addresses the issue of not acquiring the mutex for
regulator B before calling _regulator_disable(B).
Signed-off-by: NJeffrey Carlyle <jeff.carlyle@motorola.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Allow machine drivers to explicitly enable the use of the dummy regulator,
enabling simpler support for systems with only a few specific supplies
visible to software.

It is strongly recommended that this is not used on systems with
substantial software control over their PMICs, for maximum functionality
constrints should be as fully specified as possible.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

This patch fixes a typo that incorrectly reports mA numbers as uA.
Signed-off-by: NCyril Chemparathy <cyril@ti.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

If device_register() fails then call put_device().
See comment to device_register.
Signed-off-by: NVasiliy Kulikov <segooon@gmail.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Signed-off-by: NGuenter Roeck <guenter.roeck@ericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On Mon, 2010-05-17 at 17:34 +0200, Mark Brown wrote:
> This doesn't seem like the right error handling - if the driver has a
> set_mode() you'd *expect* it to have a get_mode() but there's no need
> for it to be a strict requirement.
True. In such a case, even a valid request would be lost! So now
in the updated patch:
 - check if get_mode is present to avoid oops;
 - if get_mode is not present, proceed anyways for the request.

Here is the updated patch:

>From bad0d5eb51ef84be5b100e3dd0f5a590ea0529b6 Mon Sep 17 00:00:00 2001
From: Sundar R Iyer <sundar.iyer@stericsson.com>
Date: Fri, 14 May 2010 15:14:17 +0530
Subject: [PATCH 1/1] regulator: return set_mode when same mode is requested

save I/O costs by returning when the same mode is
requested for the regulator

Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NSundar R Iyer <sundar.iyer@stericsson.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Simply remove all consumer supplies for the regulator on errors. Remove
unset_consumer_device_supply() which is no longer used.
Signed-off-by: NJani Nikula <ext-jani.1.nikula@nokia.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Remove all matching consumer supplies, not just the first, to not leave
dangling pointers.
Signed-off-by: NJani Nikula <ext-jani.1.nikula@nokia.com>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

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

Pointer comparison is not sufficient for non-NULL device name matching,
so use strcmp(). Otherwise the semantics remain the same.
Signed-off-by: NJani Nikula <ext-jani.1.nikula@nokia.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

When one regulator supplies another allow the relationship to be specified
using names rather than struct regulators, in a similar manner to that
allowed for consumer supplies. This allows static configuration at compile
time, reducing the need for dynamic init code.

Also change the references to LINE supply to be system supply since line
is sometimes used for actual supplies and therefore potentially confusing.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

WARNING: at kernel/lockdep.c:2706 sysfs_add_file_mode+0x4c/0xa8()

Difference between v1 and v2:
Moved sysfs_attr_init() call as first one to access the structure.
Signed-off-by: NAmeya Palande <ameya.palande@nokia.com>
CC: Liam Girdwood <lrg@slimlogic.co.uk>
CC: Mark Brown <broonie@opensource.wolfsonmicro.com>
CC: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

[Ss]ytem => [Ss]ystem
udpate => update
paramters => parameters
orginal => original
Signed-off-by: NThomas Weber <swirl@gmx.li>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

In order to ease transitions with drivers are boards start using regulators
provide an option to cause all regulator_get() calls to succeed, with a
dummy always on regulator being supplied where one has not been configured.
A warning is printed whenever the dummy regulator is used to aid system
development.

This regulator does not implement any regulator operations but will allow
simple consumers which only do enable() and disable() calls to run. It
is kept separate from the fixed voltage regulator to avoid Kconfig
confusion on the part of users when it is extended to allow boards to
explicitly use the dummy regulator to simplify cases where the majority
of supplies are from fixed regulators without software control.

This option is currently only effective for systems which do not specify
full constriants. If required an override could also be provided to allow
these systems to use the dummy regulator, though it is likely that
unconfigured supplies on such systems will lead to error due to
regulators being powered down more aggressively when not in use.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

If a regulator driver does not provide a way to query if the driver is
enabled then assume that it is enabled.  This is very likely to reflect
the actual state is more useful for callers than reporting an error.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NLiam Girdwood <lrg@slimlogic.co.uk>

Regulators may sometimes take longer to enable than the control operation
used to do so, either because the regulator has ramp rate control used to
limit inrush current or because the control operation is very fast (GPIO
being the most common example of this).  In order to ensure that consumers
do not rely on the regulator before it is enabled provide an enable_time()
operation and have the core delay for that time before returning to the
caller.

This is implemented as a function since the ramp rate may be specified in
voltage per unit time and therefore the time depend on the configuration.
In future it would be desirable to allow the bulk operations to run the
delays for multiple enables in parallel but this is not currently supported.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The intended use case is for drivers which disable regulators to save
power but need to do some work to restore the hardware state when
restarting.  If the supplies are not actually disabled due to board
limits or sharing with other active devices this notifier allows the
driver to avoid unneeded reinitialisation, particularly when used with
runtime PM.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>