regulator: Fairchild fan53555 support

This driver supports Fairchild FAN53555 Digitally Programmable
TinyBuck Regulator. The FAN53555 is a step-down switching voltage
regulator that delivers a digitally programmable output from an
input voltage supply of 2.5V to 5.5V. The output voltage is
programmed through an I2C interface.

Signed-off-by: Yunfan Zhang <yfzhang@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 1c6320c..a80abc4 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -110,6 +110,17 @@
 	  This driver supports the voltage regulators of DA9052-BC and
 	  DA9053-AA/Bx PMIC.
 
+config REGULATOR_FAN53555
+	tristate "Fairchild FAN53555 Regulator"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver supports Fairchild FAN53555 Digitally Programmable
+	  TinyBuck Regulator. The FAN53555 is a step-down switching voltage
+	  regulator that delivers a digitally programmable output from an
+	  input voltage supply of 2.5V to 5.5V. The output voltage is
+	  programmed through an I2C interface.
+
 config REGULATOR_ANATOP
 	tristate "Freescale i.MX on-chip ANATOP LDO regulators"
 	depends on MFD_ANATOP