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[] = {