regulator: add driver for hi6421 voltage regulator

Add driver support for HiSilicon Hi6421 voltage regulators.

Two rules for regulator enabling are defined in hi6421 spec:
1) Between disable and enable of each regulator (LDOs or BUCKs), there must
   be a protection gap. Use @off_on_delay of regulator core to implement this.
2) No two regulators can be enabled at the same time. Use mutex in
   hi6421_regulator_pdata to ensure this. A protection gap of 100us is added
   into each LDO/BUCK's .enable_time.

Signed-off-by: Guodong Xu <guodong.xu@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

3 files changed, 668 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 2dc8289e5dba..e6b98ed4c12f 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -240,6 +240,16 @@ config REGULATOR_GPIO
 	  and the platform has to provide a mapping of GPIO-states
 	  to target volts/amps.
 
+config REGULATOR_HI6421
+	tristate "HiSilicon Hi6421 PMIC voltage regulator support"
+	depends on MFD_HI6421_PMIC && OF
+	help
+	  This driver provides support for the voltage regulators on the
+	  HiSilicon Hi6421 PMU / Codec IC.
+	  Hi6421 is a multi-function device which, on regulator part, provides
+	  21 general purpose LDOs, 3 dedicated LDOs, and 5 BUCKs. All
+	  of them come with support to either ECO (idle) or sleep mode.
+
 config REGULATOR_ISL6271A
 	tristate "Intersil ISL6271A Power regulator"
 	depends on I2C
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index aa4a6aa7b558..5513e2c141b1 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_REGULATOR_DBX500_PRCMU) += dbx500-prcmu.o
 obj-$(CONFIG_REGULATOR_DB8500_PRCMU) += db8500-prcmu.o
 obj-$(CONFIG_REGULATOR_FAN53555) += fan53555.o
 obj-$(CONFIG_REGULATOR_GPIO) += gpio-regulator.o
+obj-$(CONFIG_REGULATOR_HI6421) += hi6421-regulator.o
 obj-$(CONFIG_REGULATOR_ISL6271A) += isl6271a-regulator.o
 obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o
 obj-$(CONFIG_REGULATOR_LP3972) += lp3972.o
diff --git a/drivers/regulator/hi6421-regulator.c b/drivers/regulator/hi6421-regulator.c
new file mode 100644
index 000000000000..b40851eb5466
--- /dev/null
+++ b/drivers/regulator/hi6421-regulator.c
@@ -0,0 +1,657 @@
+/*
+ * Device driver for regulators in Hi6421 IC
+ *
+ * Copyright (c) <2011-2014> HiSilicon Technologies Co., Ltd.
+ *              http://www.hisilicon.com
+ * Copyright (c) <2013-2014> Linaro Ltd.
+ *              http://www.linaro.org
+ *
+ * Author: Guodong Xu <guodong.xu@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/mfd/hi6421-pmic.h>
+#include <linux/delay.h>
+#include <linux/time.h>
+
+/*
+ * struct hi6421_regulator_pdata - Hi6421 regulator data of platform device
+ * @lock: mutex to serialize regulator enable
+ */
+struct hi6421_regulator_pdata {
+	struct mutex lock;
+};
+
+/*
+ * struct hi6421_regulator_info - hi6421 regulator information
+ * @dev: device pointer
+ * @desc: regulator description
+ * @regulator: regulator device
+ * @mode_mask: ECO mode bitmask of LDOs; for BUCKs, this masks sleep
+ * @eco_microamp: eco mode load upper limit (in mA), valid for LDOs only
+ * @valid_modes_mask: valid operating modes
+ */
+struct hi6421_regulator_info {
+	struct device		*dev;
+	struct regulator_desc	desc;
+	struct regulator_dev	*regulator;
+	u8		mode_mask;
+	u32		eco_microamp;
+	unsigned int	valid_modes_mask;
+};
+
+/* HI6421 regulators */
+enum hi6421_regulator_id {
+	HI6421_LDO0,
+	HI6421_LDO1,
+	HI6421_LDO2,
+	HI6421_LDO3,
+	HI6421_LDO4,
+	HI6421_LDO5,
+	HI6421_LDO6,
+	HI6421_LDO7,
+	HI6421_LDO8,
+	HI6421_LDO9,
+	HI6421_LDO10,
+	HI6421_LDO11,
+	HI6421_LDO12,
+	HI6421_LDO13,
+	HI6421_LDO14,
+	HI6421_LDO15,
+	HI6421_LDO16,
+	HI6421_LDO17,
+	HI6421_LDO18,
+	HI6421_LDO19,
+	HI6421_LDO20,
+	HI6421_LDOAUDIO,
+	HI6421_BUCK0,
+	HI6421_BUCK1,
+	HI6421_BUCK2,
+	HI6421_BUCK3,
+	HI6421_BUCK4,
+	HI6421_BUCK5,
+	HI6421_NUM_REGULATORS,
+};
+
+#define HI6421_REGULATOR_OF_MATCH(_name, id)				\
+{									\
+	.name = #_name,							\
+	.driver_data = (void *) HI6421_##id,				\
+}
+
+static struct of_regulator_match hi6421_regulator_match[] = {
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout0, LDO0),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout1, LDO1),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout2, LDO2),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout3, LDO3),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout4, LDO4),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout5, LDO5),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout6, LDO6),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout7, LDO7),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout8, LDO8),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout9, LDO9),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout10, LDO10),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout11, LDO11),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout12, LDO12),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout13, LDO13),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout14, LDO14),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout15, LDO15),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout16, LDO16),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout17, LDO17),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout18, LDO18),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout19, LDO19),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout20, LDO20),
+	HI6421_REGULATOR_OF_MATCH(hi6421_vout_audio, LDOAUDIO),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck0, BUCK0),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck1, BUCK1),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck2, BUCK2),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck3, BUCK3),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck4, BUCK4),
+	HI6421_REGULATOR_OF_MATCH(hi6421_buck5, BUCK5),
+};
+
+/* LDO 0, 4~7, 9~14, 16~20 have same voltage table. */
+static const unsigned int ldo_0_voltages[] = {
+	1500000, 1800000, 2400000, 2500000,
+	2600000, 2700000, 2850000, 3000000,
+};
+
+/* LDO 8, 15 have same voltage table. */
+static const unsigned int ldo_8_voltages[] = {
+	1500000, 1800000, 2400000, 2600000,
+	2700000, 2850000, 3000000, 3300000,
+};
+
+/* Ranges are sorted in ascending order. */
+static const struct regulator_linear_range ldo_audio_volt_range[] = {
+	REGULATOR_LINEAR_RANGE(2800000, 0, 3, 50000),
+	REGULATOR_LINEAR_RANGE(3000000, 4, 7, 100000),
+};
+
+static const unsigned int buck_3_voltages[] = {
+	 950000, 1050000, 1100000, 1117000,
+	1134000, 1150000, 1167000, 1200000,
+};
+
+static const unsigned int buck_4_voltages[] = {
+	1150000, 1200000, 1250000, 1350000,
+	1700000, 1800000, 1900000, 2000000,
+};
+
+static const unsigned int buck_5_voltages[] = {
+	1150000, 1200000, 1250000, 1350000,
+	1600000, 1700000, 1800000, 1900000,
+};
+
+static const struct regulator_ops hi6421_ldo_ops;
+static const struct regulator_ops hi6421_ldo_linear_ops;
+static const struct regulator_ops hi6421_ldo_linear_range_ops;
+static const struct regulator_ops hi6421_buck012_ops;
+static const struct regulator_ops hi6421_buck345_ops;
+
+#define HI6421_LDO_ENABLE_TIME (350)
+/*
+ * _id - LDO id name string
+ * v_table - voltage table
+ * vreg - voltage select register
+ * vmask - voltage select mask
+ * ereg - enable register
+ * emask - enable mask
+ * odelay - off/on delay time in uS
+ * ecomask - eco mode mask
+ * ecoamp - eco mode load uppler limit in mA
+ */
+#define HI6421_LDO(_id, v_table, vreg, vmask, ereg, emask,		\
+		   odelay, ecomask, ecoamp)				\
+	[HI6421_##_id] = {						\
+		.desc = {						\
+			.name		= #_id,				\
+			.ops		= &hi6421_ldo_ops,		\
+			.type		= REGULATOR_VOLTAGE,		\
+			.id		= HI6421_##_id,			\
+			.owner		= THIS_MODULE,			\
+			.n_voltages	= ARRAY_SIZE(v_table),		\
+			.volt_table	= v_table,			\
+			.vsel_reg	= HI6421_REG_TO_BUS_ADDR(vreg),	\
+			.vsel_mask	= vmask,			\
+			.enable_reg	= HI6421_REG_TO_BUS_ADDR(ereg),	\
+			.enable_mask	= emask,			\
+			.enable_time	= HI6421_LDO_ENABLE_TIME,	\
+			.off_on_delay	= odelay,			\
+		},							\
+		.mode_mask		= ecomask,			\
+		.eco_microamp		= ecoamp,			\
+		.valid_modes_mask	= (REGULATOR_MODE_NORMAL	\
+					   | REGULATOR_MODE_IDLE),	\
+	}
+
+/* HI6421 LDO1~3 are linear voltage regulators at fixed uV_step
+ *
+ * _id - LDO id name string
+ * _min_uV - minimum voltage supported in uV
+ * n_volt - number of votages available
+ * vstep - voltage increase in each linear step in uV
+ * vreg - voltage select register
+ * vmask - voltage select mask
+ * ereg - enable register
+ * emask - enable mask
+ * odelay - off/on delay time in uS
+ * ecomask - eco mode mask
+ * ecoamp - eco mode load uppler limit in mA
+ */
+#define HI6421_LDO_LINEAR(_id, _min_uV, n_volt, vstep, vreg, vmask,	\
+			  ereg, emask, odelay, ecomask, ecoamp)		\
+	[HI6421_##_id] = {						\
+		.desc = {						\
+			.name		= #_id,				\
+			.ops		= &hi6421_ldo_linear_ops,	\
+			.type		= REGULATOR_VOLTAGE,		\
+			.id		= HI6421_##_id,			\
+			.owner		= THIS_MODULE,			\
+			.min_uV		= _min_uV,			\
+			.n_voltages	= n_volt,			\
+			.uV_step	= vstep,			\
+			.vsel_reg	= HI6421_REG_TO_BUS_ADDR(vreg),	\
+			.vsel_mask	= vmask,			\
+			.enable_reg	= HI6421_REG_TO_BUS_ADDR(ereg),	\
+			.enable_mask	= emask,			\
+			.enable_time	= HI6421_LDO_ENABLE_TIME,	\
+			.off_on_delay	= odelay,			\
+		},							\
+		.mode_mask		= ecomask,			\
+		.eco_microamp		= ecoamp,			\
+		.valid_modes_mask	= (REGULATOR_MODE_NORMAL	\
+					   | REGULATOR_MODE_IDLE),	\
+	}
+
+/* HI6421 LDOAUDIO is a linear voltage regulator with two 4-step ranges
+ *
+ * _id - LDO id name string
+ * n_volt - number of votages available
+ * volt_ranges - array of regulator_linear_range
+ * vstep - voltage increase in each linear step in uV
+ * vreg - voltage select register
+ * vmask - voltage select mask
+ * ereg - enable register
+ * emask - enable mask
+ * odelay - off/on delay time in uS
+ * ecomask - eco mode mask
+ * ecoamp - eco mode load uppler limit in mA
+ */
+#define HI6421_LDO_LINEAR_RANGE(_id, n_volt, volt_ranges, vreg, vmask,	\
+				ereg, emask, odelay, ecomask, ecoamp)	\
+	[HI6421_##_id] = {						\
+		.desc = {						\
+			.name		= #_id,				\
+			.ops		= &hi6421_ldo_linear_range_ops,	\
+			.type		= REGULATOR_VOLTAGE,		\
+			.id		= HI6421_##_id,			\
+			.owner		= THIS_MODULE,			\
+			.n_voltages	= n_volt,			\
+			.linear_ranges	= volt_ranges,			\
+			.n_linear_ranges = ARRAY_SIZE(volt_ranges),	\
+			.vsel_reg	= HI6421_REG_TO_BUS_ADDR(vreg),	\
+			.vsel_mask	= vmask,			\
+			.enable_reg	= HI6421_REG_TO_BUS_ADDR(ereg),	\
+			.enable_mask	= emask,			\
+			.enable_time	= HI6421_LDO_ENABLE_TIME,	\
+			.off_on_delay	= odelay,			\
+		},							\
+		.mode_mask		= ecomask,			\
+		.eco_microamp		= ecoamp,			\
+		.valid_modes_mask	= (REGULATOR_MODE_NORMAL	\
+					   | REGULATOR_MODE_IDLE),	\
+	}
+
+/* HI6421 BUCK0/1/2 are linear voltage regulators at fixed uV_step
+ *
+ * _id - BUCK0/1/2 id name string
+ * vreg - voltage select register
+ * vmask - voltage select mask
+ * ereg - enable register
+ * emask - enable mask
+ * sleepmask - mask of sleep mode
+ * etime - enable time
+ * odelay - off/on delay time in uS
+ */
+#define HI6421_BUCK012(_id, vreg, vmask, ereg, emask, sleepmask,	\
+			etime, odelay)					\
+	[HI6421_##_id] = {						\
+		.desc = {						\
+			.name		= #_id,				\
+			.ops		= &hi6421_buck012_ops,		\
+			.type		= REGULATOR_VOLTAGE,		\
+			.id		= HI6421_##_id,			\
+			.owner		= THIS_MODULE,			\
+			.min_uV		= 700000,			\
+			.n_voltages	= 128,				\
+			.uV_step	= 7086,				\
+			.vsel_reg	= HI6421_REG_TO_BUS_ADDR(vreg),	\
+			.vsel_mask	= vmask,			\
+			.enable_reg	= HI6421_REG_TO_BUS_ADDR(ereg),	\
+			.enable_mask	= emask,			\
+			.enable_time	= etime,			\
+			.off_on_delay	= odelay,			\
+		},							\
+		.mode_mask		= sleepmask,			\
+		.valid_modes_mask	= (REGULATOR_MODE_NORMAL	\
+					   | REGULATOR_MODE_STANDBY),	\
+	}
+
+/* HI6421 BUCK3/4/5 share similar configurations as LDOs, with exception
+ *  that it supports SLEEP mode, so has different .ops.
+ *
+ * _id - LDO id name string
+ * v_table - voltage table
+ * vreg - voltage select register
+ * vmask - voltage select mask
+ * ereg - enable register
+ * emask - enable mask
+ * odelay - off/on delay time in uS
+ * sleepmask - mask of sleep mode
+ */
+#define HI6421_BUCK345(_id, v_table, vreg, vmask, ereg, emask,		\
+			odelay, sleepmask)				\
+	[HI6421_##_id] = {						\
+		.desc = {						\
+			.name		= #_id,				\
+			.ops		= &hi6421_buck345_ops,		\
+			.type		= REGULATOR_VOLTAGE,		\
+			.id		= HI6421_##_id,			\
+			.owner		= THIS_MODULE,			\
+			.n_voltages	= ARRAY_SIZE(v_table),		\
+			.volt_table	= v_table,			\
+			.vsel_reg	= HI6421_REG_TO_BUS_ADDR(vreg),	\
+			.vsel_mask	= vmask,			\
+			.enable_reg	= HI6421_REG_TO_BUS_ADDR(ereg),	\
+			.enable_mask	= emask,			\
+			.enable_time	= HI6421_LDO_ENABLE_TIME,	\
+			.off_on_delay	= odelay,			\
+		},							\
+		.mode_mask		= sleepmask,			\
+		.valid_modes_mask	= (REGULATOR_MODE_NORMAL	\
+					   | REGULATOR_MODE_STANDBY),	\
+	}
+
+/* HI6421 regulator information */
+static struct hi6421_regulator_info
+		hi6421_regulator_info[HI6421_NUM_REGULATORS] = {
+	HI6421_LDO(LDO0, ldo_0_voltages, 0x20, 0x07, 0x20, 0x10,
+		   10000, 0x20, 8000),
+	HI6421_LDO_LINEAR(LDO1, 1700000, 4, 100000, 0x21, 0x03, 0x21, 0x10,
+			  10000, 0x20, 5000),
+	HI6421_LDO_LINEAR(LDO2, 1050000, 8, 50000, 0x22, 0x07, 0x22, 0x10,
+			  20000, 0x20, 8000),
+	HI6421_LDO_LINEAR(LDO3, 1050000, 8, 50000, 0x23, 0x07, 0x23, 0x10,
+			  20000, 0x20, 8000),
+	HI6421_LDO(LDO4, ldo_0_voltages, 0x24, 0x07, 0x24, 0x10,
+		   20000, 0x20, 8000),
+	HI6421_LDO(LDO5, ldo_0_voltages, 0x25, 0x07, 0x25, 0x10,
+		   20000, 0x20, 8000),
+	HI6421_LDO(LDO6, ldo_0_voltages, 0x26, 0x07, 0x26, 0x10,
+		   20000, 0x20, 8000),
+	HI6421_LDO(LDO7, ldo_0_voltages, 0x27, 0x07, 0x27, 0x10,
+		   20000, 0x20, 5000),
+	HI6421_LDO(LDO8, ldo_8_voltages, 0x28, 0x07, 0x28, 0x10,
+		   20000, 0x20, 8000),
+	HI6421_LDO(LDO9, ldo_0_voltages, 0x29, 0x07, 0x29, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO10, ldo_0_voltages, 0x2a, 0x07, 0x2a, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO11, ldo_0_voltages, 0x2b, 0x07, 0x2b, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO12, ldo_0_voltages, 0x2c, 0x07, 0x2c, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO13, ldo_0_voltages, 0x2d, 0x07, 0x2d, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO14, ldo_0_voltages, 0x2e, 0x07, 0x2e, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO15, ldo_8_voltages, 0x2f, 0x07, 0x2f, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO16, ldo_0_voltages, 0x30, 0x07, 0x30, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO17, ldo_0_voltages, 0x31, 0x07, 0x31, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO18, ldo_0_voltages, 0x32, 0x07, 0x32, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO19, ldo_0_voltages, 0x33, 0x07, 0x33, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO(LDO20, ldo_0_voltages, 0x34, 0x07, 0x34, 0x10,
+		   40000, 0x20, 8000),
+	HI6421_LDO_LINEAR_RANGE(LDOAUDIO, 8, ldo_audio_volt_range, 0x36,
+				0x70, 0x36, 0x01, 40000, 0x02, 5000),
+	HI6421_BUCK012(BUCK0, 0x0d, 0x7f, 0x0c, 0x01, 0x10, 400, 20000),
+	HI6421_BUCK012(BUCK1, 0x0f, 0x7f, 0x0e, 0x01, 0x10, 400, 20000),
+	HI6421_BUCK012(BUCK2, 0x11, 0x7f, 0x10, 0x01, 0x10, 350, 100),
+	HI6421_BUCK345(BUCK3, buck_3_voltages, 0x13, 0x07, 0x12, 0x01,
+		       20000, 0x10),
+	HI6421_BUCK345(BUCK4, buck_4_voltages, 0x15, 0x07, 0x14, 0x01,
+		       20000, 0x10),
+	HI6421_BUCK345(BUCK5, buck_5_voltages, 0x17, 0x07, 0x16, 0x01,
+		       20000, 0x10),
+};
+
+static int hi6421_regulator_enable(struct regulator_dev *rdev)
+{
+	struct hi6421_regulator_pdata *pdata;
+
+	pdata = dev_get_drvdata(rdev->dev.parent);
+	/* hi6421 spec requires regulator enablement must be serialized:
+	 *  - Because when BUCK, LDO switching from off to on, it will have
+	 *    a huge instantaneous current; so you can not turn on two or
+	 *    more LDO or BUCKs simultaneously, or it may burn the chip.
+	 */
+	mutex_lock(&pdata->lock);
+
+	/* call regulator regmap helper */
+	regulator_enable_regmap(rdev);
+
+	mutex_unlock(&pdata->lock);
+	return 0;
+}
+
+static unsigned int hi6421_regulator_ldo_get_mode(struct regulator_dev *rdev)
+{
+	struct hi6421_regulator_info *info = rdev_get_drvdata(rdev);
+	u32 reg_val;
+
+	regmap_read(rdev->regmap, rdev->desc->enable_reg, &reg_val);
+	if (reg_val & info->mode_mask)
+		return REGULATOR_MODE_IDLE;
+	else
+		return REGULATOR_MODE_NORMAL;
+}
+
+static unsigned int hi6421_regulator_buck_get_mode(struct regulator_dev *rdev)
+{
+	struct hi6421_regulator_info *info = rdev_get_drvdata(rdev);
+	u32 reg_val;
+
+	regmap_read(rdev->regmap, rdev->desc->enable_reg, &reg_val);
+	if (reg_val & info->mode_mask)
+		return REGULATOR_MODE_STANDBY;
+	else
+		return REGULATOR_MODE_NORMAL;
+}
+
+static int hi6421_regulator_ldo_set_mode(struct regulator_dev *rdev,
+						unsigned int mode)
+{
+	struct hi6421_regulator_info *info = rdev_get_drvdata(rdev);
+	u32 new_mode;
+
+	switch (mode) {
+	case REGULATOR_MODE_NORMAL:
+		new_mode = 0;
+		break;
+	case REGULATOR_MODE_IDLE:
+		new_mode = info->mode_mask;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* set mode */
+	regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
+			   info->mode_mask, new_mode);
+
+	return 0;
+}
+
+static int hi6421_regulator_buck_set_mode(struct regulator_dev *rdev,
+						unsigned int mode)
+{
+	struct hi6421_regulator_info *info = rdev_get_drvdata(rdev);
+	u32 new_mode;
+
+	switch (mode) {
+	case REGULATOR_MODE_NORMAL:
+		new_mode = 0;
+		break;
+	case REGULATOR_MODE_STANDBY:
+		new_mode = info->mode_mask;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* set mode */
+	regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
+			   info->mode_mask, new_mode);
+
+	return 0;
+}
+
+unsigned int hi6421_regulator_ldo_get_optimum_mode(struct regulator_dev *rdev,
+			int input_uV, int output_uV, int load_uA)
+{
+	struct hi6421_regulator_info *info = rdev_get_drvdata(rdev);
+
+	if (load_uA > info->eco_microamp)
+		return REGULATOR_MODE_NORMAL;
+	else
+		return REGULATOR_MODE_IDLE;
+}
+
+static const struct regulator_ops hi6421_ldo_ops = {
+	.is_enabled = regulator_is_enabled_regmap,
+	.enable = hi6421_regulator_enable,
+	.disable = regulator_disable_regmap,
+	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_mode = hi6421_regulator_ldo_get_mode,
+	.set_mode = hi6421_regulator_ldo_set_mode,
+	.get_optimum_mode = hi6421_regulator_ldo_get_optimum_mode,
+};
+
+static const struct regulator_ops hi6421_ldo_linear_ops = {
+	.is_enabled = regulator_is_enabled_regmap,
+	.enable = hi6421_regulator_enable,
+	.disable = regulator_disable_regmap,
+	.list_voltage = regulator_list_voltage_linear,
+	.map_voltage = regulator_map_voltage_linear,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_mode = hi6421_regulator_ldo_get_mode,
+	.set_mode = hi6421_regulator_ldo_set_mode,
+	.get_optimum_mode = hi6421_regulator_ldo_get_optimum_mode,
+};
+
+static const struct regulator_ops hi6421_ldo_linear_range_ops = {
+	.is_enabled = regulator_is_enabled_regmap,
+	.enable = hi6421_regulator_enable,
+	.disable = regulator_disable_regmap,
+	.list_voltage = regulator_list_voltage_linear_range,
+	.map_voltage = regulator_map_voltage_linear_range,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_mode = hi6421_regulator_ldo_get_mode,
+	.set_mode = hi6421_regulator_ldo_set_mode,
+	.get_optimum_mode = hi6421_regulator_ldo_get_optimum_mode,
+};
+
+static const struct regulator_ops hi6421_buck012_ops = {
+	.is_enabled = regulator_is_enabled_regmap,
+	.enable = hi6421_regulator_enable,
+	.disable = regulator_disable_regmap,
+	.list_voltage = regulator_list_voltage_linear,
+	.map_voltage = regulator_map_voltage_linear,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_mode = hi6421_regulator_buck_get_mode,
+	.set_mode = hi6421_regulator_buck_set_mode,
+};
+
+static const struct regulator_ops hi6421_buck345_ops = {
+	.is_enabled = regulator_is_enabled_regmap,
+	.enable = hi6421_regulator_enable,
+	.disable = regulator_disable_regmap,
+	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_mode = hi6421_regulator_buck_get_mode,
+	.set_mode = hi6421_regulator_buck_set_mode,
+};
+
+static int hi6421_regulator_register(struct platform_device *pdev,
+				     struct regmap *rmap,
+				     struct regulator_init_data *init_data,
+				     int id, struct device_node *np)
+{
+	struct hi6421_regulator_info *info = NULL;
+	struct regulator_config config = { };
+
+	/* assign per-regulator data */
+	info = &hi6421_regulator_info[id];
+	info->dev = &pdev->dev;
+
+	config.dev = &pdev->dev;
+	config.init_data = init_data;
+	config.driver_data = info;
+	config.regmap = rmap;
+	config.of_node = np;
+
+	/* register regulator with framework */
+	info->regulator = devm_regulator_register(&pdev->dev, &info->desc,
+						&config);
+	if (IS_ERR(info->regulator)) {
+		dev_err(&pdev->dev, "failed to register regulator %s\n",
+			info->desc.name);
+		return PTR_ERR(info->regulator);
+	}
+
+	return 0;
+}
+
+static int hi6421_regulator_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	struct hi6421_pmic *pmic;
+	struct hi6421_regulator_pdata *pdata;
+	int i, ret = 0;
+
+	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+	mutex_init(&pdata->lock);
+	platform_set_drvdata(pdev, pdata);
+
+	np = of_get_child_by_name(dev->parent->of_node, "regulators");
+	if (!np)
+		return -ENODEV;
+
+	ret = of_regulator_match(dev, np,
+				 hi6421_regulator_match,
+				 ARRAY_SIZE(hi6421_regulator_match));
+	of_node_put(np);
+	if (ret < 0) {
+		dev_err(dev, "Error parsing regulator init data: %d\n", ret);
+		return ret;
+	}
+
+	pmic = dev_get_drvdata(dev->parent);
+
+	for (i = 0; i < ARRAY_SIZE(hi6421_regulator_info); i++) {
+		ret = hi6421_regulator_register(pdev, pmic->regmap,
+			hi6421_regulator_match[i].init_data, i,
+			hi6421_regulator_match[i].of_node);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver hi6421_regulator_driver = {
+	.driver = {
+		.name	= "hi6421-regulator",
+		.owner  = THIS_MODULE,
+	},
+	.probe	= hi6421_regulator_probe,
+};
+module_platform_driver(hi6421_regulator_driver);
+
+MODULE_AUTHOR("Guodong Xu <guodong.xu@linaro.org>");
+MODULE_DESCRIPTION("Hi6421 regulator driver");
+MODULE_LICENSE("GPL v2");