For some hardwares ramp_delay for BUCKs is a configurable parameter which can
be configured through DT or board file.This patch adds ramp_delay to regulator
constraints and allow user to configure it for regulators which supports this
feature, through DT or board file. It will provide two ways of setting the
ramp_delay for a regulator:
	First, by setting it as constraints in board file(for configurable
regulators) and set_machine_constraints() will take care of setting it on
hardware by calling(the provided) .set_ramp_delay() operation(callback).
	Second, by setting it as data in regulator_desc(as fixed/default
ramp_delay rate) for a regulator in driver.

regulator_set_voltage_time_sel() will give preference to
constraints->ramp_delay while reading ramp_delay rate for regulator. Similarly
users should also take care accordingly while refering ramp_delay rate(in case
of implementing their private .set_voltage_time_sel() callbacks for different
regulators).

[Rewrote subject for 80 columns -- broonie]
Signed-off-by: NYadwinder Singh Brar <yadi.brar@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Looking up init data for regulators found on chips is a common operation
that can be handled in a generic way. The new helper function introduced
by this patch looks up the children of a given node by names specified
in a match table and fills that match table with information parsed from
the DT.

This is based on work by Rhyland Klein <rklein@nvidia.com>.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

apply_uV is errornously set when regulator is instantiated from device
tree, even when it doesn't contain any voltage constraints.

This commit fixes error:

  machine_constraints_voltage: CHARGER: failed to apply 0uV constraint

for following regulator description in DTS:

  CHARGER {
	regulator-min-microamp = <100000>;
	regulator-max-microamp = <200000>;
  }
Signed-off-by: NKarol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It's not always true that the device_node of regulator can be found
at dev->of_node at the time when of_get_regulator_init_data() is being
called, because in some cases the regulator nodes in device tree do
not have 'struct device' behind them until regulator_dev gets created
for it by core function regulator_register().

The patch adds device_node as a new parameter to
of_get_regulator_init_data(), so that caller can pass in the node of
regulator directly.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Liam Girdwood <lrg@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Otherwise there is no way in the bindings to configure a fixed voltage
via software. It seems reasonable to assume that if the binding explicitly
specifies a voltage we want to actually use that voltage.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

of_get_regulator_init_data is called in drivers/regulator/fixed.c
which could be a module.

Export of_get_regulator_init_data to fix below build error:
ERROR: "of_get_regulator_init_data" [drivers/regulator/fixed.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
Reported-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The helper routine is meant to be used by the regulator drivers
to extract the regulator_init_data structure from the data
that is passed from device tree.
'consumer_supplies' which is part of regulator_init_data is not extracted
as the regulator consumer mappings are passed through DT differently,
implemented in subsequent patches.
Similarly the regulator<-->parent/supply mapping is handled in
subsequent patches.

Also add documentation for regulator bindings to be used to pass
regulator_init_data struct information from device tree.

Some of the regulator properties which are linux and board specific,
are left out since its not clear if they can
be in someway embedded into the kernel or passed in from DT.
They will be revisited later.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>