/*
* 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/slab.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 << 6);
}
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);
}
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");
