regulator: Support ROHM BD71815 regulators

Support voltage control for regulators on ROHM BD71815 PMIC.

ROHM BD71815 contains 5 bucks, 7 LDOs and a boost (intended for LED).
Bucks 1 and 2 support HW state based voltage level and enable states. Other
regulators support HW state based enable states. All bucks and LDOs 1-5
allow voltage changes for RUN state and LDO4 can be enabled/disabled via
GPIO.

LDO3 does support changing between two predetermined voltages by using
a GPIO but this functionality is not included in this commit.

This work is derived from driver originally written by Tony Luo
<luofc@embedinfo.com> - although not much of original work is left.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/regulator/Kconfig

@@ -204,6 +204,17 @@ config REGULATOR_BD70528
 	  This driver can also be built as a module. If so, the module
 	  will be called bd70528-regulator.
 
+config REGULATOR_BD71815
+	tristate "ROHM BD71815 Power Regulator"
+	depends on MFD_ROHM_BD71828
+	help
+	  This driver supports voltage regulators on ROHM BD71815 PMIC.
+	  This will enable support for the software controllable buck
+	  and LDO regulators and a current regulator for LEDs.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called bd71815-regulator.
+
 config REGULATOR_BD71828
 	tristate "ROHM BD71828 Power Regulator"
 	depends on MFD_ROHM_BD71828

drivers/regulator/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_REGULATOR_ATC260X) += atc260x-regulator.o
 obj-$(CONFIG_REGULATOR_AXP20X) += axp20x-regulator.o
 obj-$(CONFIG_REGULATOR_BCM590XX) += bcm590xx-regulator.o
 obj-$(CONFIG_REGULATOR_BD70528) += bd70528-regulator.o
+obj-$(CONFIG_REGULATOR_BD71815)	+= bd71815-regulator.o
 obj-$(CONFIG_REGULATOR_BD71828) += bd71828-regulator.o
 obj-$(CONFIG_REGULATOR_BD718XX) += bd718x7-regulator.o
 obj-$(CONFIG_REGULATOR_BD9571MWV) += bd9571mwv-regulator.o