regulator: enable max8649 regulator driver

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 408 insertions, 0 deletions

diff --git a/drivers/regulator/max8649.c b/drivers/regulator/max8649.c
new file mode 100644
index 000000000000..3ebdf698c648
--- /dev/null
+++ b/drivers/regulator/max8649.c
@@ -0,0 +1,408 @@
+/*
+ * Regulators driver for Maxim max8649
+ *
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/max8649.h>
+
+#define MAX8649_DCDC_VMIN       750000          /* uV */
+#define MAX8649_DCDC_VMAX       1380000         /* uV */
+#define MAX8649_DCDC_STEP       10000           /* uV */
+#define MAX8649_VOL_MASK        0x3f
+
+/* Registers */
+#define MAX8649_MODE0           0x00
+#define MAX8649_MODE1           0x01
+#define MAX8649_MODE2           0x02
+#define MAX8649_MODE3           0x03
+#define MAX8649_CONTROL         0x04
+#define MAX8649_SYNC            0x05
+#define MAX8649_RAMP            0x06
+#define MAX8649_CHIP_ID1        0x08
+#define MAX8649_CHIP_ID2        0x09
+
+/* Bits */
+#define MAX8649_EN_PD           (1 << 7)
+#define MAX8649_VID0_PD         (1 << 6)
+#define MAX8649_VID1_PD         (1 << 5)
+#define MAX8649_VID_MASK        (3 << 5)
+
+#define MAX8649_FORCE_PWM       (1 << 7)
+#define MAX8649_SYNC_EXTCLK     (1 << 6)
+
+#define MAX8649_EXT_MASK        (3 << 6)
+
+#define MAX8649_RAMP_MASK       (7 << 5)
+#define MAX8649_RAMP_DOWN       (1 << 1)
+
+struct max8649_regulator_info {
+        struct regulator_dev    *regulator;
+        struct i2c_client       *i2c;
+        struct device           *dev;
+        struct mutex            io_lock;
+
+        int             vol_reg;
+        unsigned        mode:2; /* bit[1:0] = VID1, VID0 */
+        unsigned        extclk_freq:2;
+        unsigned        extclk:1;
+        unsigned        ramp_timing:3;
+        unsigned        ramp_down:1;
+};
+
+/* I2C operations */
+
+static inline int max8649_read_device(struct i2c_client *i2c,
+                                      int reg, int bytes, void *dest)
+{
+        unsigned char data;
+        int ret;
+
+        data = (unsigned char)reg;
+        ret = i2c_master_send(i2c, &data, 1);
+        if (ret < 0)
+                return ret;
+        ret = i2c_master_recv(i2c, dest, bytes);
+        if (ret < 0)
+                return ret;
+        return 0;
+}
+
+static inline int max8649_write_device(struct i2c_client *i2c,
+                                       int reg, int bytes, void *src)
+{
+        unsigned char buf[bytes + 1];
+        int ret;
+
+        buf[0] = (unsigned char)reg;
+        memcpy(&buf[1], src, bytes);
+
+        ret = i2c_master_send(i2c, buf, bytes + 1);
+        if (ret < 0)
+                return ret;
+        return 0;
+}
+
+static int max8649_reg_read(struct i2c_client *i2c, int reg)
+{
+        struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
+        unsigned char data;
+        int ret;
+
+        mutex_lock(&info->io_lock);
+        ret = max8649_read_device(i2c, reg, 1, &data);
+        mutex_unlock(&info->io_lock);
+
+        if (ret < 0)
+                return ret;
+        return (int)data;
+}
+
+static int max8649_set_bits(struct i2c_client *i2c, int reg,
+                            unsigned char mask, unsigned char data)
+{
+        struct max8649_regulator_info *info = i2c_get_clientdata(i2c);
+        unsigned char value;
+        int ret;
+
+        mutex_lock(&info->io_lock);
+        ret = max8649_read_device(i2c, reg, 1, &value);
+        if (ret < 0)
+                goto out;
+        value &= ~mask;
+        value |= data;
+        ret = max8649_write_device(i2c, reg, 1, &value);
+out:
+        mutex_unlock(&info->io_lock);
+        return ret;
+}
+
+static inline int check_range(int min_uV, int max_uV)
+{
+        if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
+                || (min_uV > max_uV))
+                return -EINVAL;
+        return 0;
+}
+
+static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
+{
+        return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
+}
+
+static int max8649_get_voltage(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        unsigned char data;
+        int ret;
+
+        ret = max8649_reg_read(info->i2c, info->vol_reg);
+        if (ret < 0)
+                return ret;
+        data = (unsigned char)ret & MAX8649_VOL_MASK;
+        return max8649_list_voltage(rdev, data);
+}
+
+static int max8649_set_voltage(struct regulator_dev *rdev,
+                               int min_uV, int max_uV)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        unsigned char data, mask;
+
+        if (check_range(min_uV, max_uV)) {
+                dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
+                        min_uV, max_uV);
+                return -EINVAL;
+        }
+        data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
+                / MAX8649_DCDC_STEP;
+        mask = MAX8649_VOL_MASK;
+
+        return max8649_set_bits(info->i2c, info->vol_reg, mask, data);
+}
+
+/* EN_PD means pulldown on EN input */
+static int max8649_enable(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD, 0);
+}
+
+/*
+ * Applied internal pulldown resistor on EN input pin.
+ * If pulldown EN pin outside, it would be better.
+ */
+static int max8649_disable(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        return max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_EN_PD,
+                                MAX8649_EN_PD);
+}
+
+static int max8649_is_enabled(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        int ret;
+
+        ret = max8649_reg_read(info->i2c, MAX8649_CONTROL);
+        if (ret < 0)
+                return ret;
+        return !((unsigned char)ret & MAX8649_EN_PD);
+}
+
+static int max8649_enable_time(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        int voltage, rate, ret;
+
+        /* get voltage */
+        ret = max8649_reg_read(info->i2c, info->vol_reg);
+        if (ret < 0)
+                return ret;
+        ret &= MAX8649_VOL_MASK;
+        voltage = max8649_list_voltage(rdev, (unsigned char)ret); /* uV */
+
+        /* get rate */
+        ret = max8649_reg_read(info->i2c, MAX8649_RAMP);
+        if (ret < 0)
+                return ret;
+        ret = (ret & MAX8649_RAMP_MASK) >> 5;
+        rate = (32 * 1000) >> ret;      /* uV/uS */
+
+        return (voltage / rate);
+}
+
+static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+
+        switch (mode) {
+        case REGULATOR_MODE_FAST:
+                max8649_set_bits(info->i2c, info->vol_reg, MAX8649_FORCE_PWM,
+                                 MAX8649_FORCE_PWM);
+                break;
+        case REGULATOR_MODE_NORMAL:
+                max8649_set_bits(info->i2c, info->vol_reg,
+                                 MAX8649_FORCE_PWM, 0);
+                break;
+        default:
+                return -EINVAL;
+        }
+        return 0;
+}
+
+static unsigned int max8649_get_mode(struct regulator_dev *rdev)
+{
+        struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+        int ret;
+
+        ret = max8649_reg_read(info->i2c, info->vol_reg);
+        if (ret & MAX8649_FORCE_PWM)
+                return REGULATOR_MODE_FAST;
+        return REGULATOR_MODE_NORMAL;
+}
+
+static struct regulator_ops max8649_dcdc_ops = {
+        .set_voltage    = max8649_set_voltage,
+        .get_voltage    = max8649_get_voltage,
+        .list_voltage   = max8649_list_voltage,
+        .enable         = max8649_enable,
+        .disable        = max8649_disable,
+        .is_enabled     = max8649_is_enabled,
+        .enable_time    = max8649_enable_time,
+        .set_mode       = max8649_set_mode,
+        .get_mode       = max8649_get_mode,
+
+};
+
+static struct regulator_desc dcdc_desc = {
+        .name           = "max8649",
+        .ops            = &max8649_dcdc_ops,
+        .type           = REGULATOR_VOLTAGE,
+        .n_voltages     = 1 << 6,
+        .owner          = THIS_MODULE,
+};
+
+static int __devinit max8649_regulator_probe(struct i2c_client *client,
+                                             const struct i2c_device_id *id)
+{
+        struct max8649_platform_data *pdata = client->dev.platform_data;
+        struct max8649_regulator_info *info = NULL;
+        unsigned char data;
+        int ret;
+
+        info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
+        if (!info) {
+                dev_err(&client->dev, "No enough memory\n");
+                return -ENOMEM;
+        }
+
+        info->i2c = client;
+        info->dev = &client->dev;
+        mutex_init(&info->io_lock);
+        i2c_set_clientdata(client, info);
+
+        info->mode = pdata->mode;
+        switch (info->mode) {
+        case 0:
+                info->vol_reg = MAX8649_MODE0;
+                break;
+        case 1:
+                info->vol_reg = MAX8649_MODE1;
+                break;
+        case 2:
+                info->vol_reg = MAX8649_MODE2;
+                break;
+        case 3:
+                info->vol_reg = MAX8649_MODE3;
+                break;
+        default:
+                break;
+        }
+
+        ret = max8649_reg_read(info->i2c, MAX8649_CHIP_ID1);
+        if (ret < 0) {
+                dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
+                        ret);
+                goto out;
+        }
+        dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);
+
+        /* enable VID0 & VID1 */
+        max8649_set_bits(info->i2c, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
+
+        /* enable/disable external clock synchronization */
+        info->extclk = pdata->extclk;
+        data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
+        max8649_set_bits(info->i2c, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
+        if (info->extclk) {
+                /* set external clock frequency */
+                info->extclk_freq = pdata->extclk_freq;
+                max8649_set_bits(info->i2c, MAX8649_SYNC, MAX8649_EXT_MASK,
+                                 info->extclk_freq);
+        }
+
+        if (pdata->ramp_timing) {
+                info->ramp_timing = pdata->ramp_timing;
+                max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_MASK,
+                                 info->ramp_timing << 5);
+        }
+
+        info->ramp_down = pdata->ramp_down;
+        if (info->ramp_down) {
+                max8649_set_bits(info->i2c, MAX8649_RAMP, MAX8649_RAMP_DOWN,
+                                 MAX8649_RAMP_DOWN);
+        }
+
+        info->regulator = regulator_register(&dcdc_desc, &client->dev,
+                                             pdata->regulator, info);
+        if (IS_ERR(info->regulator)) {
+                dev_err(info->dev, "failed to register regulator %s\n",
+                        dcdc_desc.name);
+                ret = PTR_ERR(info->regulator);
+                goto out;
+        }
+
+        dev_info(info->dev, "Max8649 regulator device is detected.\n");
+        return 0;
+out:
+        kfree(info);
+        return ret;
+}
+
+static int __devexit max8649_regulator_remove(struct i2c_client *client)
+{
+        struct max8649_regulator_info *info = i2c_get_clientdata(client);
+
+        if (info) {
+                if (info->regulator)
+                        regulator_unregister(info->regulator);
+                kfree(info);
+        }
+        i2c_set_clientdata(client, NULL);
+
+        return 0;
+}
+
+static const struct i2c_device_id max8649_id[] = {
+        { "max8649", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, max8649_id);
+
+static struct i2c_driver max8649_driver = {
+        .probe          = max8649_regulator_probe,
+        .remove         = __devexit_p(max8649_regulator_remove),
+        .driver         = {
+                .name   = "max8649",
+        },
+        .id_table       = max8649_id,
+};
+
+static int __init max8649_init(void)
+{
+        return i2c_add_driver(&max8649_driver);
+}
+subsys_initcall(max8649_init);
+
+static void __exit max8649_exit(void)
+{
+        i2c_del_driver(&max8649_driver);
+}
+module_exit(max8649_exit);
+
+/* Module information */
+MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+