This adds a regulator driver for the TI bq24022 Single-Chip
Li-Ion Charger with its nCE and ISET2 pins connected to GPIOs.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>

This patch adds support for fixed regulators. This class of regulator is
not software controllable but can coexist on machines with software
controlable regulators.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>

This interface is for machine specific code and allows the creation of
voltage/current domains (with constraints) for each regulator. It can
provide regulator constraints that will prevent device damage through
overvoltage or over current caused by buggy client drivers. It also
allows the creation of a regulator tree whereby some regulators are
supplied by others (similar to a clock tree).

Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

This allows regulator drivers to register their regulators and provide
operations to the core. It also has a notifier call chain for propagating
regulator events to clients.

Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Add support to allow consumer device drivers to control their regulator
power supply.

This uses a similar API to the kernel clock interface in that consumer
drivers can get and put a regulator (like they can with clocks atm) and
get/set voltage, current limit, mode, enable and disable. This should
allow consumers complete control over their supply voltage and current
limit. This also compiles out if not in use so drivers can be reused in
systems with no regulator based power control.

Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>