LP3971 PMIC regulator driver (updated and combined version)

This patch adds regulator drivers for National Semiconductors LP3971 PMIC.
This LP3971 PMIC controller has 3 DC/DC voltage converters and 5 low
drop-out (LDO) regulators. LP3971 PMIC controller uses I2C interface.

Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

3 files changed, 570 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 5bec17cf1d5c..f4317798e47c 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -110,4 +110,11 @@ config REGULATOR_PCF50633
          Say Y here to support the voltage regulators and convertors
          on PCF50633
 
+config REGULATOR_LP3971
+        tristate "National Semiconductors LP3971 PMIC regulator driver"
+        depends on I2C
+        help
+         Say Y here to support the voltage regulators and convertors
+         on National Semiconductors LP3971 PMIC
+
 endif
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index faf7bcc1af98..4d762c4cccfd 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_REGULATOR_VIRTUAL_CONSUMER) += virtual.o
 obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
 
 obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o
+obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
 obj-$(CONFIG_REGULATOR_TWL4030) += twl4030-regulator.o
 obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o
diff --git a/drivers/regulator/lp3971.c b/drivers/regulator/lp3971.c
new file mode 100644
index 000000000000..35abebea4ed5
--- /dev/null
+++ b/drivers/regulator/lp3971.c
@@ -0,0 +1,562 @@
+/*
+ * Regulator driver for National Semiconductors LP3971 PMIC chip
+ *
+ *  Copyright (C) 2009 Samsung Electronics
+ *  Author: Marek Szyprowski <m.szyprowski@samsung.com>
+ *
+ * Based on wm8350.c
+ *
+ * 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/bug.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/lp3971.h>
+
+struct lp3971 {
+        struct device *dev;
+        struct mutex io_lock;
+        struct i2c_client *i2c;
+        int num_regulators;
+        struct regulator_dev **rdev;
+};
+
+static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg);
+static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val);
+
+#define LP3971_SYS_CONTROL1_REG 0x07
+
+/* System control register 1 initial value,
+   bits 4 and 5 are EPROM programmable */
+#define SYS_CONTROL1_INIT_VAL 0x40
+#define SYS_CONTROL1_INIT_MASK 0xCF
+
+#define LP3971_BUCK_VOL_ENABLE_REG 0x10
+#define LP3971_BUCK_VOL_CHANGE_REG 0x20
+
+/*      Voltage control registers shift:
+        LP3971_BUCK1 -> 0
+        LP3971_BUCK2 -> 4
+        LP3971_BUCK3 -> 6
+*/
+#define BUCK_VOL_CHANGE_SHIFT(x) (((1 << x) & ~0x01) << 1)
+#define BUCK_VOL_CHANGE_FLAG_GO 0x01
+#define BUCK_VOL_CHANGE_FLAG_TARGET 0x02
+#define BUCK_VOL_CHANGE_FLAG_MASK 0x03
+
+#define LP3971_BUCK1_BASE 0x23
+#define LP3971_BUCK2_BASE 0x29
+#define LP3971_BUCK3_BASE 0x32
+
+const static int buck_base_addr[] = {
+        LP3971_BUCK1_BASE,
+        LP3971_BUCK2_BASE,
+        LP3971_BUCK3_BASE,
+};
+
+#define LP3971_BUCK_TARGET_VOL1_REG(x) (buck_base_addr[x])
+#define LP3971_BUCK_TARGET_VOL2_REG(x) (buck_base_addr[x]+1)
+
+const static int buck_voltage_map[] = {
+           0,  800,  850,  900,  950, 1000, 1050, 1100,
+        1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500,
+        1550, 1600, 1650, 1700, 1800, 1900, 2500, 2800,
+        3000, 3300,
+};
+
+#define BUCK_TARGET_VOL_MASK 0x3f
+#define BUCK_TARGET_VOL_MIN_IDX 0x01
+#define BUCK_TARGET_VOL_MAX_IDX 0x19
+
+#define LP3971_BUCK_RAMP_REG(x) (buck_base_addr[x]+2)
+
+#define LP3971_LDO_ENABLE_REG 0x12
+#define LP3971_LDO_VOL_CONTR_BASE 0x39
+
+/*      Voltage control registers:
+        LP3971_LDO1 -> LP3971_LDO_VOL_CONTR_BASE + 0
+        LP3971_LDO2 -> LP3971_LDO_VOL_CONTR_BASE + 0
+        LP3971_LDO3 -> LP3971_LDO_VOL_CONTR_BASE + 1
+        LP3971_LDO4 -> LP3971_LDO_VOL_CONTR_BASE + 1
+        LP3971_LDO5 -> LP3971_LDO_VOL_CONTR_BASE + 2
+*/
+#define LP3971_LDO_VOL_CONTR_REG(x)     (LP3971_LDO_VOL_CONTR_BASE + (x >> 1))
+
+/*      Voltage control registers shift:
+        LP3971_LDO1 -> 0, LP3971_LDO2 -> 4
+        LP3971_LDO3 -> 0, LP3971_LDO4 -> 4
+        LP3971_LDO5 -> 0
+*/
+#define LDO_VOL_CONTR_SHIFT(x) ((x & 1) << 2)
+#define LDO_VOL_CONTR_MASK 0x0f
+
+const static int ldo45_voltage_map[] = {
+        1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350,
+        1400, 1500, 1800, 1900, 2500, 2800, 3000, 3300,
+};
+
+const static int ldo123_voltage_map[] = {
+        1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500,
+        2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300,
+};
+
+const static int *ldo_voltage_map[] = {
+        ldo123_voltage_map, /* LDO1 */
+        ldo123_voltage_map, /* LDO2 */
+        ldo123_voltage_map, /* LDO3 */
+        ldo45_voltage_map, /* LDO4 */
+        ldo45_voltage_map, /* LDO5 */
+};
+
+#define LDO_VOL_VALUE_MAP(x) (ldo_voltage_map[(x - LP3971_LDO1)])
+
+#define LDO_VOL_MIN_IDX 0x00
+#define LDO_VOL_MAX_IDX 0x0f
+
+static int lp3971_ldo_list_voltage(struct regulator_dev *dev, unsigned index)
+{
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        return 1000 * LDO_VOL_VALUE_MAP(ldo)[index];
+}
+
+static int lp3971_ldo_is_enabled(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        u16 mask = 1 << (1 + ldo);
+        u16 val;
+
+        val = lp3971_reg_read(lp3971, LP3971_LDO_ENABLE_REG);
+        return (val & mask) != 0;
+}
+
+static int lp3971_ldo_enable(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        u16 mask = 1 << (1 + ldo);
+
+        return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, mask);
+}
+
+static int lp3971_ldo_disable(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        u16 mask = 1 << (1 + ldo);
+
+        return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, 0);
+}
+
+static int lp3971_ldo_get_voltage(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        u16 val, reg;
+
+        reg = lp3971_reg_read(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo));
+        val = (reg >> LDO_VOL_CONTR_SHIFT(ldo)) & LDO_VOL_CONTR_MASK;
+
+        return 1000 * LDO_VOL_VALUE_MAP(ldo)[val];
+}
+
+static int lp3971_ldo_set_voltage(struct regulator_dev *dev,
+                                  int min_uV, int max_uV)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int ldo = rdev_get_id(dev) - LP3971_LDO1;
+        int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
+        const int *vol_map = LDO_VOL_VALUE_MAP(ldo);
+        u16 val;
+
+        if (min_vol < vol_map[LDO_VOL_MIN_IDX] ||
+            min_vol > vol_map[LDO_VOL_MAX_IDX])
+                return -EINVAL;
+
+        for (val = LDO_VOL_MIN_IDX; val <= LDO_VOL_MAX_IDX; val++)
+                if (vol_map[val] >= min_vol)
+                        break;
+
+        if (vol_map[val] > max_vol)
+                return -EINVAL;
+
+        return lp3971_set_bits(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo),
+                LDO_VOL_CONTR_MASK << LDO_VOL_CONTR_SHIFT(ldo), val);
+}
+
+static struct regulator_ops lp3971_ldo_ops = {
+        .list_voltage = lp3971_ldo_list_voltage,
+        .is_enabled = lp3971_ldo_is_enabled,
+        .enable = lp3971_ldo_enable,
+        .disable = lp3971_ldo_disable,
+        .get_voltage = lp3971_ldo_get_voltage,
+        .set_voltage = lp3971_ldo_set_voltage,
+};
+
+static int lp3971_dcdc_list_voltage(struct regulator_dev *dev, unsigned index)
+{
+        return 1000 * buck_voltage_map[index];
+}
+
+static int lp3971_dcdc_is_enabled(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int buck = rdev_get_id(dev) - LP3971_DCDC1;
+        u16 mask = 1 << (buck * 2);
+        u16 val;
+
+        val = lp3971_reg_read(lp3971, LP3971_BUCK_VOL_ENABLE_REG);
+        return (val & mask) != 0;
+}
+
+static int lp3971_dcdc_enable(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int buck = rdev_get_id(dev) - LP3971_DCDC1;
+        u16 mask = 1 << (buck * 2);
+
+        return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, mask);
+}
+
+static int lp3971_dcdc_disable(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int buck = rdev_get_id(dev) - LP3971_DCDC1;
+        u16 mask = 1 << (buck * 2);
+
+        return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, 0);
+}
+
+static int lp3971_dcdc_get_voltage(struct regulator_dev *dev)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int buck = rdev_get_id(dev) - LP3971_DCDC1;
+        u16 reg;
+        int val;
+
+        reg = lp3971_reg_read(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck));
+        reg &= BUCK_TARGET_VOL_MASK;
+
+        if (reg <= BUCK_TARGET_VOL_MAX_IDX)
+                val = 1000 * buck_voltage_map[reg];
+        else {
+                val = 0;
+                dev_warn(&dev->dev, "chip reported incorrect voltage value.\n");
+        }
+
+        return val;
+}
+
+static int lp3971_dcdc_set_voltage(struct regulator_dev *dev,
+                                  int min_uV, int max_uV)
+{
+        struct lp3971 *lp3971 = rdev_get_drvdata(dev);
+        int buck = rdev_get_id(dev) - LP3971_DCDC1;
+        int min_vol = min_uV / 1000, max_vol = max_uV / 1000;
+        const int *vol_map = buck_voltage_map;
+        u16 val;
+        int ret;
+
+        if (min_vol < vol_map[BUCK_TARGET_VOL_MIN_IDX] ||
+            min_vol > vol_map[BUCK_TARGET_VOL_MAX_IDX])
+                return -EINVAL;
+
+        for (val = BUCK_TARGET_VOL_MIN_IDX; val <= BUCK_TARGET_VOL_MAX_IDX;
+             val++)
+                if (vol_map[val] >= min_vol)
+                        break;
+
+        if (vol_map[val] > max_vol)
+                return -EINVAL;
+
+        ret = lp3971_set_bits(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck),
+               BUCK_TARGET_VOL_MASK, val);
+        if (ret)
+                return ret;
+
+        ret = lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
+               BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
+               BUCK_VOL_CHANGE_FLAG_GO << BUCK_VOL_CHANGE_SHIFT(buck));
+        if (ret)
+                return ret;
+
+        return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
+               BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
+               0 << BUCK_VOL_CHANGE_SHIFT(buck));
+}
+
+static struct regulator_ops lp3971_dcdc_ops = {
+        .list_voltage = lp3971_dcdc_list_voltage,
+        .is_enabled = lp3971_dcdc_is_enabled,
+        .enable = lp3971_dcdc_enable,
+        .disable = lp3971_dcdc_disable,
+        .get_voltage = lp3971_dcdc_get_voltage,
+        .set_voltage = lp3971_dcdc_set_voltage,
+};
+
+static struct regulator_desc regulators[] = {
+        {
+                .name = "LDO1",
+                .id = LP3971_LDO1,
+                .ops = &lp3971_ldo_ops,
+                .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "LDO2",
+                .id = LP3971_LDO2,
+                .ops = &lp3971_ldo_ops,
+                .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "LDO3",
+                .id = LP3971_LDO3,
+                .ops = &lp3971_ldo_ops,
+                .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "LDO4",
+                .id = LP3971_LDO4,
+                .ops = &lp3971_ldo_ops,
+                .n_voltages = ARRAY_SIZE(ldo45_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "LDO5",
+                .id = LP3971_LDO5,
+                .ops = &lp3971_ldo_ops,
+                .n_voltages = ARRAY_SIZE(ldo45_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "DCDC1",
+                .id = LP3971_DCDC1,
+                .ops = &lp3971_dcdc_ops,
+                .n_voltages = ARRAY_SIZE(buck_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "DCDC2",
+                .id = LP3971_DCDC2,
+                .ops = &lp3971_dcdc_ops,
+                .n_voltages = ARRAY_SIZE(buck_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+        {
+                .name = "DCDC3",
+                .id = LP3971_DCDC3,
+                .ops = &lp3971_dcdc_ops,
+                .n_voltages = ARRAY_SIZE(buck_voltage_map),
+                .type = REGULATOR_VOLTAGE,
+                .owner = THIS_MODULE,
+        },
+};
+
+static int lp3971_i2c_read(struct i2c_client *i2c, char reg, int count,
+        u16 *dest)
+{
+        int ret;
+
+        if (count != 1)
+                return -EIO;
+        ret = i2c_smbus_read_byte_data(i2c, reg);
+        if (ret < 0 || count != 1)
+                return -EIO;
+
+        *dest = ret;
+        return 0;
+}
+
+static int lp3971_i2c_write(struct i2c_client *i2c, char reg, int count,
+        const u16 *src)
+{
+        int ret;
+
+        if (count != 1)
+                return -EIO;
+        ret = i2c_smbus_write_byte_data(i2c, reg, *src);
+        if (ret >= 0)
+                return 0;
+
+        return ret;
+}
+
+static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg)
+{
+        u16 val = 0;
+
+        mutex_lock(&lp3971->io_lock);
+
+        lp3971_i2c_read(lp3971->i2c, reg, 1, &val);
+
+        dev_dbg(lp3971->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
+                (unsigned)val&0xff);
+
+        mutex_unlock(&lp3971->io_lock);
+
+        return val & 0xff;
+}
+
+static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val)
+{
+        u16 tmp;
+        int ret;
+
+        mutex_lock(&lp3971->io_lock);
+
+        ret = lp3971_i2c_read(lp3971->i2c, reg, 1, &tmp);
+        tmp = (tmp & ~mask) | val;
+        if (ret == 0) {
+                ret = lp3971_i2c_write(lp3971->i2c, reg, 1, &tmp);
+                dev_dbg(lp3971->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
+                        (unsigned)val&0xff);
+        }
+        mutex_unlock(&lp3971->io_lock);
+
+        return ret;
+}
+
+static int setup_regulators(struct lp3971 *lp3971,
+        struct lp3971_platform_data *pdata)
+{
+        int i, err;
+        int num_regulators = pdata->num_regulators;
+        lp3971->num_regulators = num_regulators;
+        lp3971->rdev = kzalloc(sizeof(struct regulator_dev *) * num_regulators,
+                GFP_KERNEL);
+
+        /* Instantiate the regulators */
+        for (i = 0; i < num_regulators; i++) {
+                int id = pdata->regulators[i].id;
+                lp3971->rdev[i] = regulator_register(&regulators[id],
+                        lp3971->dev, pdata->regulators[i].initdata, lp3971);
+
+                err = IS_ERR(lp3971->rdev[i]);
+                if (err) {
+                        dev_err(lp3971->dev, "regulator init failed: %d\n",
+                                err);
+                        goto error;
+                }
+        }
+
+        return 0;
+error:
+        for (i = 0; i < num_regulators; i++)
+                if (lp3971->rdev[i])
+                        regulator_unregister(lp3971->rdev[i]);
+        kfree(lp3971->rdev);
+        lp3971->rdev = NULL;
+        return err;
+}
+
+static int __devinit lp3971_i2c_probe(struct i2c_client *i2c,
+                            const struct i2c_device_id *id)
+{
+        struct lp3971 *lp3971;
+        struct lp3971_platform_data *pdata = i2c->dev.platform_data;
+        int ret;
+        u16 val;
+
+        lp3971 = kzalloc(sizeof(struct lp3971), GFP_KERNEL);
+        if (lp3971 == NULL) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        lp3971->i2c = i2c;
+        lp3971->dev = &i2c->dev;
+        i2c_set_clientdata(i2c, lp3971);
+
+        mutex_init(&lp3971->io_lock);
+
+        /* Detect LP3971 */
+        ret = lp3971_i2c_read(i2c, LP3971_SYS_CONTROL1_REG, 1, &val);
+        if (ret == 0 && (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL)
+                ret = -ENODEV;
+        if (ret < 0) {
+                dev_err(&i2c->dev, "failed to detect device\n");
+                goto err_detect;
+        }
+
+        if (pdata) {
+                ret = setup_regulators(lp3971, pdata);
+                if (ret < 0)
+                        goto err_detect;
+        } else
+                dev_warn(lp3971->dev, "No platform init data supplied\n");
+
+        return 0;
+
+err_detect:
+        i2c_set_clientdata(i2c, NULL);
+        kfree(lp3971);
+err:
+        return ret;
+}
+
+static int __devexit lp3971_i2c_remove(struct i2c_client *i2c)
+{
+        struct lp3971 *lp3971 = i2c_get_clientdata(i2c);
+        int i;
+        for (i = 0; i < lp3971->num_regulators; i++)
+                if (lp3971->rdev[i])
+                        regulator_unregister(lp3971->rdev[i]);
+        kfree(lp3971->rdev);
+        i2c_set_clientdata(i2c, NULL);
+        kfree(lp3971);
+
+        return 0;
+}
+
+static const struct i2c_device_id lp3971_i2c_id[] = {
+       { "lp3971", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, lp3971_i2c_id);
+
+static struct i2c_driver lp3971_i2c_driver = {
+        .driver = {
+                .name = "LP3971",
+                .owner = THIS_MODULE,
+        },
+        .probe    = lp3971_i2c_probe,
+        .remove   = lp3971_i2c_remove,
+        .id_table = lp3971_i2c_id,
+};
+
+static int __init lp3971_module_init(void)
+{
+        int ret = -ENODEV;
+
+        ret = i2c_add_driver(&lp3971_i2c_driver);
+        if (ret != 0)
+                pr_err("Failed to register I2C driver: %d\n", ret);
+
+        return ret;
+}
+module_init(lp3971_module_init);
+
+static void __exit lp3971_module_exit(void)
+{
+        i2c_del_driver(&lp3971_i2c_driver);
+}
+module_exit(lp3971_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marek Szyprowski <m.szyprowski@samsung.com>");
+MODULE_DESCRIPTION("LP3971 PMIC driver");