regulator: mpq7920: add mpq7920 regulator driver

Adding regulator driver for the device mpq7920.
The MPQ7920 PMIC device contains four DC-DC buck converters and
five regulators, is designed for automotive and accessed over I2C.

Fixed sparse warning reported on this patch
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Saravanan Sekar <sravanhome@gmail.com>
Link: https://lore.kernel.org/r/20200109195346.30270-1-sravanhome@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -623,6 +623,16 @@ config REGULATOR_MP8859
 	  Say M here if you want to include support for the regulator as a
 	  module. The module will be named "mp8859".
 
+config REGULATOR_MPQ7920
+	tristate "Monolithic MPQ7920 PMIC"
+	depends on I2C && OF
+	select REGMAP_I2C
+	help
+	  Say y here to support the MPQ7920 PMIC. This will enable supports
+	  the software controllable 4 buck and 5 LDO regulators.
+	  This driver supports the control of different power rails of device
+	  through regulator interface.
+
 config REGULATOR_MT6311
 	tristate "MediaTek MT6311 PMIC"
 	depends on I2C

drivers/regulator/Makefile

@@ -79,6 +79,7 @@ obj-$(CONFIG_REGULATOR_MC13892) += mc13892-regulator.o
 obj-$(CONFIG_REGULATOR_MC13XXX_CORE) +=  mc13xxx-regulator-core.o
 obj-$(CONFIG_REGULATOR_MCP16502) += mcp16502.o
 obj-$(CONFIG_REGULATOR_MP8859) += mp8859.o
+obj-$(CONFIG_REGULATOR_MPQ7920) += mpq7920.o
 obj-$(CONFIG_REGULATOR_MT6311) += mt6311-regulator.o
 obj-$(CONFIG_REGULATOR_MT6323)	+= mt6323-regulator.o
 obj-$(CONFIG_REGULATOR_MT6358)	+= mt6358-regulator.o

drivers/regulator/mpq7920.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * mpq7920.h  -  Regulator definitions for mpq7920
+ *
+ * Copyright 2019 Monolithic Power Systems, Inc
+ *
+ */
+
+#ifndef __MPQ7920_H__
+#define __MPQ7920_H__
+
+#define MPQ7920_REG_CTL0		0x00
+#define MPQ7920_REG_CTL1		0x01
+#define MPQ7920_REG_CTL2		0x02
+#define MPQ7920_BUCK1_REG_A		0x03
+#define MPQ7920_BUCK1_REG_B		0x04
+#define MPQ7920_BUCK1_REG_C		0x05
+#define MPQ7920_BUCK1_REG_D		0x06
+#define MPQ7920_BUCK2_REG_A		0x07
+#define MPQ7920_BUCK2_REG_B		0x08
+#define MPQ7920_BUCK2_REG_C		0x09
+#define MPQ7920_BUCK2_REG_D		0x0a
+#define MPQ7920_BUCK3_REG_A		0x0b
+#define MPQ7920_BUCK3_REG_B		0x0c
+#define MPQ7920_BUCK3_REG_C		0x0d
+#define MPQ7920_BUCK3_REG_D		0x0e
+#define MPQ7920_BUCK4_REG_A		0x0f
+#define MPQ7920_BUCK4_REG_B		0x10
+#define MPQ7920_BUCK4_REG_C		0x11
+#define MPQ7920_BUCK4_REG_D		0x12
+#define MPQ7920_LDO1_REG_A		0x13
+#define MPQ7920_LDO1_REG_B		0x0
+#define MPQ7920_LDO2_REG_A		0x14
+#define MPQ7920_LDO2_REG_B		0x15
+#define MPQ7920_LDO2_REG_C		0x16
+#define MPQ7920_LDO3_REG_A		0x17
+#define MPQ7920_LDO3_REG_B		0x18
+#define MPQ7920_LDO3_REG_C		0x19
+#define MPQ7920_LDO4_REG_A		0x1a
+#define MPQ7920_LDO4_REG_B		0x1b
+#define MPQ7920_LDO4_REG_C		0x1c
+#define MPQ7920_LDO5_REG_A		0x1d
+#define MPQ7920_LDO5_REG_B		0x1e
+#define MPQ7920_LDO5_REG_C		0x1f
+#define MPQ7920_REG_MODE		0x20
+#define MPQ7920_REG_REGULATOR_EN1	0x22
+#define MPQ7920_REG_REGULATOR_EN	0x22
+
+#define MPQ7920_MASK_VREF		0x7f
+#define MPQ7920_MASK_BUCK_ILIM		0xd0
+#define MPQ7920_MASK_LDO_ILIM		BIT(6)
+#define MPQ7920_MASK_DISCHARGE		BIT(5)
+#define MPQ7920_MASK_MODE		0xc0
+#define MPQ7920_MASK_SOFTSTART		0x0c
+#define MPQ7920_MASK_SWITCH_FREQ	0x30
+#define MPQ7920_MASK_BUCK_PHASE_DEALY	0x30
+#define MPQ7920_MASK_DVS_SLEWRATE	0xc0
+#define MPQ7920_DISCHARGE_ON		0x1
+
+#define MPQ7920_REGULATOR_EN_OFFSET	7
+
+/* values in mV */
+#define MPQ7920_BUCK_VOLT_MIN		400000
+#define MPQ7920_LDO_VOLT_MIN		650000
+#define MPQ7920_VOLT_MAX		3587500
+#define MPQ7920_VOLT_STEP		12500
+
+#endif /* __MPQ7920_H__ */