The AMS AS3722 is a compact system PMU suitable for mobile phones,
tablets etc. It has 4 DCDC step down regulators, 3 DCDC step down
controller, 11 LDOs.

Add a driver to support accessing the DCDC/LDOs found on the AMS
AS3722 PMIC using regulators.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Florian Lobmaier <florian.lobmaier@ams.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

The ST Microelectronics STw481x PMIC used for the Nomadik
has one single software-controlled regulator for VMMC.
This driver registers directly to the compatible string
as there is just one regulator.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

When a system has said that it has fully specified constraints for its
regulators it is still possible that some supplies may be missing,
especially if regulator support has been added to a driver after the
board was integrated. We can handle such situations more gracefully by
providing a dummy regulator.

Unless the caller has specifically indicated that the system design may
not include a given regulator by using regulator_get_optional() or that
it needs its interactions to have an effect using regulator_get_exclusive()
provide a dummy regulator if we can't locate a real one.

The kconfig option REGULATOR_DUMMY that provided similar behaviour for all
regulators has been removed, systems that need it should flag that they
have full constraints instead.

Signed-off-by: Mark Brown <broonie@linaro.org>

lp872x regulator driver can be built a module after commit 631a1fc
"regulator: build: Allow most regulators to be built as modules".
Make REGULATOR_LP872X depend on I2C to allow building lp872x module when I2C=m.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Mostly for testing without bloating the kernel image rather than actual
utility.

Signed-off-by: Mark Brown <broonie@linaro.org>