/*
    bq2415x_charger.c - bq2415x charger driver
    Copyright (C) 2011  Pali Rohár <pali.rohar@gmail.com>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

/*
  Datasheets:
  http://www.ti.com/product/bq24150
  http://www.ti.com/product/bq24150a
  http://www.ti.com/product/bq24152
  http://www.ti.com/product/bq24153
  http://www.ti.com/product/bq24153a
  http://www.ti.com/product/bq24155
*/

#include <linux/version.h>
#include <linux/module.h>
#include <linux/param.h>
#include <linux/err.h>
#include <linux/workqueue.h>
#include <linux/sysfs.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/power_supply.h>
#include <linux/idr.h>
#include <linux/leds.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#include "bq2415x_charger.h"

#define BQ2415X_WATCHDOG_TIMEOUT	10

#define BQ2415X_REG_STATUS		0x00
#define BQ2415X_REG_CONTROL		0x01
#define BQ2415X_REG_VOLTAGE		0x02
#define BQ2415X_REG_VENDER		0x03
#define BQ2415X_REG_CURRENT		0x04

/* reset state for all registers */
#define BQ2415X_RESET_STATUS		BIT(6)
#define BQ2415X_RESET_CONTROL		(BIT(4)|BIT(5))
#define BQ2415X_RESET_VOLTAGE		(BIT(1)|BIT(3))
#define BQ2415X_RESET_CURRENT		(BIT(0)|BIT(3)|BIT(7))

/* status register */
#define BQ2415X_BIT_TMR_RST		7
#define BQ2415X_BIT_OTG			7
#define BQ2415X_BIT_EN_STAT		6
#define BQ2415X_MASK_STAT		(BIT(4)|BIT(5))
#define BQ2415X_SHIFT_STAT		4
#define BQ2415X_BIT_BOOST		3
#define BQ2415X_MASK_FAULT		(BIT(0)|BIT(1)|BIT(2))
#define BQ2415X_SHIFT_FAULT		0

/* control register */
#define BQ2415X_MASK_LIMIT		(BIT(6)|BIT(7))
#define BQ2415X_SHIFT_LIMIT		6
#define BQ2415X_MASK_VLOWV		(BIT(4)|BIT(5))
#define BQ2415X_SHIFT_VLOWV		4
#define BQ2415X_BIT_TE			3
#define BQ2415X_BIT_CE			2
#define BQ2415X_BIT_HZ_MODE		1
#define BQ2415X_BIT_OPA_MODE		0

/* voltage register */
#define BQ2415X_MASK_VO			(BIT(2)|BIT(3)|BIT(4)|BIT(5)|BIT(6)|BIT(7))
#define BQ2415X_SHIFT_VO		2
#define BQ2415X_BIT_OTG_PL		1
#define BQ2415X_BIT_OTG_EN		0

/* vender register */
#define BQ2415X_MASK_VENDER		(BIT(5)|BIT(6)|BIT(7))
#define BQ2415X_SHIFT_VENDER		5
#define BQ2415X_MASK_PN			(BIT(3)|BIT(4))
#define BQ2415X_SHIFT_PN		4
#define BQ2415X_MASK_REVISION		(BIT(0)|BIT(1)|BIT(2))
#define BQ2415X_SHIFT_REVISION		0

/* current register */
/* RESET				BIT(7) */
#define BQ2415X_MASK_VI_CHRG		(BIT(4)|BIT(5)|BIT(6))
#define BQ2415X_SHIFT_VI_CHRG		4
/* N/A					BIT(3) */
#define BQ2415X_MASK_VI_TERM		(BIT(0)|BIT(1)|BIT(2))
#define BQ2415X_SHIFT_VI_TERM		0

struct bq2415x_regulator {
	struct regulator_ops ops;
	struct regulator_desc desc;
	struct regulator_dev *dev;
};

struct bq2415x_device {
	struct device *dev;
	struct bq2415x_platform_data *platform_data;
	struct bq2415x_regulator current_limit;
	struct bq2415x_regulator weak_battery_voltage;
	struct bq2415x_regulator battery_regulation_voltage;
	struct bq2415x_regulator charge_current_sense_voltage;
	struct bq2415x_regulator termination_current_sense_voltage;
	struct led_classdev led;
	struct power_supply charger;
	struct delayed_work work;
	int watchdog;
	enum bq2415x_chip chip;
	char *name;
	int id;
};

static DEFINE_IDR(bq2415x_id);
static DEFINE_MUTEX(bq2415x_mutex);

/* i2c read functions */

static int bq2415x_i2c_read(struct bq2415x_device *bq, u8 reg)
{
	struct i2c_client *client = to_i2c_client(bq->dev);
	struct i2c_msg msg[2];
	u8 val;
	int ret;

	dev_info(bq->dev, "bq2415x_i2c_read reg=%#x\n", reg);

	if (!client->adapter)
		return -ENODEV;

	msg[0].addr = client->addr;
	msg[0].flags = 0;
	msg[0].buf = &reg;
	msg[0].len = sizeof(reg);
	msg[1].addr = client->addr;
	msg[1].flags = I2C_M_RD;
	msg[1].buf = &val;
	msg[1].len = sizeof(val);

	mutex_lock(&bq2415x_mutex);
	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	mutex_unlock(&bq2415x_mutex);

	if (ret < 0)
		return ret;

	return val;
}

static int bq2415x_i2c_read_mask(struct bq2415x_device *bq, u8 reg, u8 mask, u8 shift)
{
	int ret;

	dev_info(bq->dev, "bq2415x_i2c_read_mask reg=%#x mask=%#x shift=%#x\n", reg, mask, shift);

	if (shift > 8)
		return -EINVAL;

	ret = bq2415x_i2c_read(bq, reg);
	if (ret < 0)
		return ret;
	else
		return (ret & mask) >> shift;
}

static int bq2415x_i2c_read_bit(struct bq2415x_device *bq, u8 reg, u8 bit)
{
	if (bit > 8)
		return -EINVAL;
	else
		return bq2415x_i2c_read_mask(bq, reg, BIT(bit), bit);
}

/* i2c write functions */

static int bq2415x_i2c_write(struct bq2415x_device *bq, u8 reg, u8 val)
{
	struct i2c_client *client = to_i2c_client(bq->dev);
	struct i2c_msg msg[1];
	u8 data[2];
	int ret;

	dev_info(bq->dev, "bq2415x_i2c_write reg=%#x val=%#x\n", reg, val);

	data[0] = reg;
	data[1] = val;

	msg[0].addr = client->addr;
	msg[0].flags = 0;
	msg[0].buf = data;
	msg[0].len = ARRAY_SIZE(data);

	mutex_lock(&bq2415x_mutex);
	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
	mutex_unlock(&bq2415x_mutex);

	/* i2c_transfer returns number of messages transferred */
	if (ret < 0)
		return ret;
	else if (ret != 1)
		return -EIO;

	return 0;
}

static int bq2415x_i2c_write_mask(struct bq2415x_device *bq, u8 reg, u8 val, u8 mask, u8 shift)
{
	int ret;

	dev_info(bq->dev, "bq2415x_i2c_write_mask reg=%#x val=%#x mask=%#x shift=%#x\n", reg, val, mask, shift);

	if (shift > 8)
		return -EINVAL;

	ret = bq2415x_i2c_read(bq, reg);
	if (ret < 0)
		return ret;

	ret &= ~mask;
	ret |= val << shift;

	return bq2415x_i2c_write(bq, reg, ret);
}

static int bq2415x_i2c_write_bit(struct bq2415x_device *bq, u8 reg, bool val, u8 bit)
{
	if (bit > 8)
		return -EINVAL;
	else
		return bq2415x_i2c_write_mask(bq, reg, val, BIT(bit), bit);
}

/* global detect chip */

enum bq2415x_chip bq2415x_detect_chip(struct bq2415x_device *bq)
{
	struct i2c_client *client = to_i2c_client(bq->dev);
	int ret = bq2415x_exec_command(bq, BQ2415X_PART_NUMBER);
	if (ret < 0)
		return ret;
	if (client->addr == 0x6b) {
		switch (ret) {
			case 0:
				if (bq->chip == BQ24151A)
					return bq->chip;
				else
					return BQ24151;
			case 1:
				if (bq->chip == BQ24150A || bq->chip == BQ24152 || bq->chip == BQ24155)
					return bq->chip;
				else
					return BQ24150;
			case 2:
				if (bq->chip == BQ24153A)
					return bq->chip;
				else
					return BQ24153;
			default:
				return BQUNKNOWN;
		}
	} else if (client->addr == 0x6a) {
		switch (ret) {
			case 0:
				if (bq->chip == BQ24156A)
					return bq->chip;
				else
					return BQ24156;
			case 2:
				return BQ24158;
			default:
				return BQUNKNOWN;
		}
	}
	return BQUNKNOWN;
}
EXPORT_SYMBOL_GPL(bq2415x_detect_chip);

/* global exec command function */

int bq2415x_exec_command(struct bq2415x_device *bq, enum bq2415x_command command)
{
	switch(command)
	{
		case BQ2415X_WATCHDOG_RESET:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_STATUS, 1, BQ2415X_BIT_TMR_RST);
		case BQ2415X_OTG_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_STATUS, BQ2415X_BIT_OTG);
		case BQ2415X_STAT_PIN_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_STATUS, BQ2415X_BIT_EN_STAT);
		case BQ2415X_STAT_PIN_ENABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_STATUS, 1, BQ2415X_BIT_EN_STAT);
		case BQ2415X_STAT_PIN_DISABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_STATUS, 0, BQ2415X_BIT_EN_STAT);
		case BQ2415X_CHARGE_STATUS:
			return bq2415x_i2c_read_mask(bq, BQ2415X_REG_STATUS, BQ2415X_MASK_STAT, BQ2415X_SHIFT_STAT);
		case BQ2415X_BOOST_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_STATUS, BQ2415X_BIT_BOOST);
		case BQ2415X_FAULT_STATUS:
			return bq2415x_i2c_read_mask(bq, BQ2415X_REG_STATUS, BQ2415X_MASK_FAULT, BQ2415X_SHIFT_FAULT);

		case BQ2415X_CHARGE_CURRENT_TERMINATION_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL, BQ2415X_BIT_TE);
		case BQ2415X_CHARGE_CURRENT_TERMINATION_ENABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 1, BQ2415X_BIT_TE);
		case BQ2415X_CHARGE_CURRENT_TERMINATION_DISABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 0, BQ2415X_BIT_TE);
		case BQ2415X_CHARGER_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL, BQ2415X_BIT_CE);
		case BQ2415X_CHARGER_ENABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 1, BQ2415X_BIT_CE);
		case BQ2415X_CHARGER_DISABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 0, BQ2415X_BIT_CE);
		case BQ2415X_HIGH_IMPEDANCE_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL, BQ2415X_BIT_HZ_MODE);
		case BQ2415X_HIGH_IMPEDANCE_ENABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 1, BQ2415X_BIT_HZ_MODE);
		case BQ2415X_HIGH_IMPEDANCE_DISABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 0, BQ2415X_BIT_HZ_MODE);
		case BQ2415X_MODE:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL, BQ2415X_BIT_OPA_MODE);
		case BQ2415X_SET_BOOST_MODE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 1, BQ2415X_BIT_OPA_MODE);
		case BQ2415X_SET_CHARGER_MODE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL, 0, BQ2415X_BIT_OPA_MODE);

		case BQ2415X_OTG_HIGH_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_VOLTAGE, BQ2415X_BIT_OTG_PL);
		case BQ2415X_OTG_HIGH_ACTIVATE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_VOLTAGE, 1, BQ2415X_BIT_OTG_PL);
		case BQ2415X_OTG_LOW_ACTIVATE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_VOLTAGE, 0, BQ2415X_BIT_OTG_PL);
		case BQ2415X_OTG_PIN_STATUS:
			return bq2415x_i2c_read_bit(bq, BQ2415X_REG_VOLTAGE, BQ2415X_BIT_OTG_EN);
		case BQ2415X_OTG_PIN_ENABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_VOLTAGE, 1, BQ2415X_BIT_OTG_EN);
		case BQ2415X_OTG_PIN_DISABLE:
			return bq2415x_i2c_write_bit(bq, BQ2415X_REG_VOLTAGE, 0, BQ2415X_BIT_OTG_EN);

		case BQ2415X_VENDER_CODE:
			return bq2415x_i2c_read_mask(bq, BQ2415X_REG_VENDER, BQ2415X_MASK_VENDER, BQ2415X_SHIFT_VENDER);
		case BQ2415X_PART_NUMBER:
			return bq2415x_i2c_read_mask(bq, BQ2415X_REG_VENDER, BQ2415X_MASK_PN, BQ2415X_SHIFT_PN);
		case BQ2415X_REVISION:
			return bq2415x_i2c_read_mask(bq, BQ2415X_REG_VENDER, BQ2415X_MASK_REVISION, BQ2415X_SHIFT_REVISION);

		default:
			return -EINVAL;
	}
}
EXPORT_SYMBOL_GPL(bq2415x_exec_command);

/* global other functions */

#define bq2415x_set_default_value(bq, value) \
	do { \
		int ret = 0; \
		if (bq->platform_data->value != -1) \
			ret = bq2415x_set_##value(bq, bq->platform_data->value); \
		if (ret < 0) \
			return ret; \
	} while (0)

int bq2415x_set_defaults(struct bq2415x_device *bq)
{
	bq2415x_exec_command(bq, BQ2415X_CHARGER_DISABLE);
	bq2415x_set_default_value(bq, current_limit);
	bq2415x_set_default_value(bq, weak_battery_voltage);
	bq2415x_set_default_value(bq, battery_regulation_voltage);
	bq2415x_set_default_value(bq, charge_current_sense_voltage);
	bq2415x_set_default_value(bq, termination_current_sense_voltage);
	bq2415x_exec_command(bq, BQ2415X_CHARGER_ENABLE);
	return 0;
}
EXPORT_SYMBOL_GPL(bq2415x_set_defaults);

#undef bq2415x_set_default_value

void bq2415x_reset_chip(struct bq2415x_device *bq)
{
	bq2415x_i2c_write(bq, BQ2415X_REG_CURRENT, BQ2415X_RESET_CURRENT);
	bq2415x_i2c_write(bq, BQ2415X_REG_VOLTAGE, BQ2415X_RESET_VOLTAGE);
	bq2415x_i2c_write(bq, BQ2415X_REG_CONTROL, BQ2415X_RESET_CONTROL);
	bq2415x_i2c_write(bq, BQ2415X_REG_STATUS, BQ2415X_RESET_STATUS);
}
EXPORT_SYMBOL_GPL(bq2415x_reset_chip);

int bq2415x_set_current_limit(struct bq2415x_device *bq, int mA)
{
	int val = (mA/100 + (mA%100 > 0 ? 1 : 0) - 1) / 4;

	if (val < 0)
		val = 0;

	if (val > 3)
		val = 3;

	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CONTROL, val, BQ2415X_MASK_LIMIT, BQ2415X_SHIFT_LIMIT);
}
EXPORT_SYMBOL_GPL(bq2415x_set_current_limit);

int bq2415x_get_current_limit(struct bq2415x_device *bq)
{
	int ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CONTROL, BQ2415X_MASK_LIMIT, BQ2415X_SHIFT_LIMIT);
	if (ret < 0)
		return ret;
	else
		return 100 * (1 + 4*ret);
}
EXPORT_SYMBOL_GPL(bq2415x_get_current_limit);

int bq2415x_set_weak_battery_voltage(struct bq2415x_device *bq, int mV)
{
	int val = mV/100 + (mV%100 > 0 ? 1 : 0) - 34;

	if (val < 0)
		val = 0;

	if (val > 3)
		return -EINVAL;

	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CONTROL, val, BQ2415X_MASK_VLOWV, BQ2415X_SHIFT_VLOWV);
}
EXPORT_SYMBOL_GPL(bq2415x_set_weak_battery_voltage);

int bq2415x_get_weak_battery_voltage(struct bq2415x_device *bq)
{
	int ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CONTROL, BQ2415X_MASK_VLOWV, BQ2415X_SHIFT_VLOWV);
	if (ret < 0)
		return ret;
	else
		return 100 * (34 + ret);
}
EXPORT_SYMBOL_GPL(bq2415x_get_weak_battery_voltage);

int bq2415x_set_battery_regulation_voltage(struct bq2415x_device *bq, int mV)
{
	int val = mV/10 + (mV%10 > 0 ? 1 : 0) - 350;

	if (val < 0)
		val = 0;

	if (val > 94) /* FIXME: Max is 94 or 122 ? */
		return -EINVAL;

	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_VOLTAGE, val, BQ2415X_MASK_VO, BQ2415X_SHIFT_VO);
}
EXPORT_SYMBOL_GPL(bq2415x_set_battery_regulation_voltage);

int bq2415x_get_battery_regulation_voltage(struct bq2415x_device *bq)
{
	int ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_VOLTAGE, BQ2415X_MASK_VO, BQ2415X_SHIFT_VO);
	if (ret < 0)
		return ret;
	else
		return 10 * (350 + ret);
}
EXPORT_SYMBOL_GPL(bq2415x_get_battery_regulation_voltage);

int bq2415x_set_charge_current_sense_voltage(struct bq2415x_device *bq, int mV)
{
	/* TODO */
	return -1;
}
EXPORT_SYMBOL_GPL(bq2415x_set_charge_current_sense_voltage);

int bq2415x_get_charge_current_sense_voltage(struct bq2415x_device *bq)
{
	/* TODO */
	return -1;
}
EXPORT_SYMBOL_GPL(bq2415x_get_charge_current_sense_voltage);

int bq2415x_set_termination_current_sense_voltage(struct bq2415x_device *bq, int mV)
{
	/* TODO */
	return -1;
}
EXPORT_SYMBOL_GPL(bq2415x_set_termination_current_sense_voltage);

int bq2415x_get_termination_current_sense_voltage(struct bq2415x_device *bq)
{
	/* TODO */
	return -1;
}
EXPORT_SYMBOL_GPL(bq2415x_get_termination_current_sense_voltage);

/* current limit regulator */

static int bq2415x_regulator_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_set_current_limit(bq, min_uA / 1000);
}

static int bq2415x_regulator_get_current_limit(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_get_current_limit(bq) * 1000;
}

struct regulator_ops bq2415x_regulator_current_limit = {
	.set_current_limit = bq2415x_regulator_set_current_limit,
	.get_current_limit = bq2415x_regulator_get_current_limit,
};

/* weak battery voltage regulator */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
static int bq2415x_regulator_list_weak_battery_voltage(struct regulator_dev *rdev, unsigned selector)
{
	if (selector > 3)
		return 0;
	else
		return 100000 * (34 + selector);
}
#endif

static int bq2415x_regulator_set_weak_battery_voltage(struct regulator_dev *rdev, int min_uV, int max_uV
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
		, unsigned *selector
#endif
		)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_set_weak_battery_voltage(bq, min_uV / 1000);
}

static int bq2415x_regulator_get_weak_battery_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_get_weak_battery_voltage(bq) * 1000;
}

static struct regulator_ops bq2415x_regulator_weak_battery_voltage = {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
	.list_voltage = bq2415x_regulator_list_weak_battery_voltage,
#endif
	.set_voltage = bq2415x_regulator_set_weak_battery_voltage,
	.get_voltage = bq2415x_regulator_get_weak_battery_voltage,
};

/* battery regulation voltage regulator */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
static int bq2415x_regulator_list_battery_regulation_voltage(struct regulator_dev *rdev, unsigned selector)
{
	if (selector > 94) /* FIXME: Max is 94 or 122 ? */
		return 0;
	else
		return 10000 * (350 + selector);
}
#endif

static int bq2415x_regulator_set_battery_regulation_voltage(struct regulator_dev *rdev, int min_uV, int max_uV
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
		, unsigned *selector
#endif
		)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_set_battery_regulation_voltage(bq, min_uV / 1000);
}

static int bq2415x_regulator_get_battery_regulation_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_get_battery_regulation_voltage(bq) * 1000;
}

static struct regulator_ops bq2415x_regulator_battery_regulation_voltage = {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
	.list_voltage = bq2415x_regulator_list_battery_regulation_voltage,
#endif
	.set_voltage = bq2415x_regulator_set_battery_regulation_voltage,
	.get_voltage = bq2415x_regulator_get_battery_regulation_voltage,
};

/* charge current sense voltage regulator */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
static int bq2415x_regulator_list_charge_current_sense_voltage(struct regulator_dev *rdev, unsigned selector)
{
	/* TODO */
	return 0;
}
#endif

static int bq2415x_regulator_set_charge_current_sense_voltage(struct regulator_dev *rdev, int min_uV, int max_uV
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
		, unsigned *selector
#endif
		)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_set_charge_current_sense_voltage(bq, min_uV / 1000);
}

static int bq2415x_regulator_get_charge_current_sense_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_get_charge_current_sense_voltage(bq) * 1000;
}

static struct regulator_ops bq2415x_regulator_charge_current_sense_voltage = {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
	.list_voltage = bq2415x_regulator_list_charge_current_sense_voltage,
#endif
	.set_voltage = bq2415x_regulator_set_charge_current_sense_voltage,
	.get_voltage = bq2415x_regulator_get_charge_current_sense_voltage,
};

/* termination current sense voltage regulator */

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
static int bq2415x_regulator_list_termination_current_sense_voltage(struct regulator_dev *rdev, unsigned selector)
{
	/* TODO */
	return 0;
}
#endif

static int bq2415x_regulator_set_termination_current_sense_voltage(struct regulator_dev *rdev, int min_uV, int max_uV
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
		, unsigned *selector
#endif
		)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_set_termination_current_sense_voltage(bq, min_uV / 1000);
}

static int bq2415x_regulator_get_termination_current_sense_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_get_termination_current_sense_voltage(bq) * 1000;
}

static int bq2415x_regulator_enable_termination_current_sense_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_exec_command(bq, BQ2415X_CHARGE_CURRENT_TERMINATION_ENABLE);
}

static int bq2415x_regulator_disable_termination_current_sense_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_exec_command(bq, BQ2415X_CHARGE_CURRENT_TERMINATION_DISABLE);
}

static int bq2415x_regulator_is_enabled_termination_current_sense_voltage(struct regulator_dev *rdev)
{
	struct bq2415x_device *bq = rdev_get_drvdata(rdev);
	return bq2415x_exec_command(bq, BQ2415X_CHARGE_CURRENT_TERMINATION_STATUS);
}

static struct regulator_ops bq2415x_regulator_termination_current_sense_voltage = {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
	.list_voltage = bq2415x_regulator_list_termination_current_sense_voltage,
#endif
	.set_voltage = bq2415x_regulator_set_termination_current_sense_voltage,
	.get_voltage = bq2415x_regulator_get_termination_current_sense_voltage,
	.enable = bq2415x_regulator_enable_termination_current_sense_voltage,
	.disable = bq2415x_regulator_disable_termination_current_sense_voltage,
	.is_enabled = bq2415x_regulator_is_enabled_termination_current_sense_voltage,
};

#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,32)
#define regulator_register2(desc, dev, init, data) regulator_register(desc, dev, init, data)
#else
#define regulator_register2(desc, dev, init, data) regulator_register(desc, dev, data)
#endif

#define bq2415x_regulator_register(bq, rname, rid, rtype) \
	do { \
		bq->rname.desc.name = __stringify(rname); \
		bq->rname.desc.id = rid; \
		bq->rname.desc.type = rtype; \
		bq->rname.desc.owner = THIS_MODULE; \
		bq->rname.desc.ops = &bq2415x_regulator_##rname; \
		bq->rname.dev = regulator_register2(&bq->rname.desc, bq->dev, NULL, bq); \
		if (IS_ERR(bq->rname.dev)) \
			return PTR_ERR(bq->rname.dev); \
	} while (0)

#define bq2415x_regulator_unregister(bq, rname) regulator_unregister(bq->rname.dev)

static int bq2415x_regulator_init(struct bq2415x_device *bq)
{
/*	bq2415x_regulator_register(bq, current_limit, 0, REGULATOR_CURRENT);
	bq2415x_regulator_register(bq, weak_battery_voltage, 1, REGULATOR_VOLTAGE);
	bq2415x_regulator_register(bq, battery_regulation_voltage, 2, REGULATOR_VOLTAGE);
	bq2415x_regulator_register(bq, charge_current_sense_voltage, 3, REGULATOR_VOLTAGE);
	bq2415x_regulator_register(bq, ermination_current_sense_voltage, 4, REGULATOR_VOLTAGE);*/
	return 0;
}

static void bq2415x_regulator_exit(struct bq2415x_device *bq)
{
/*	bq2415x_regulator_unregister(bq, current_limit);
	bq2415x_regulator_unregister(bq, weak_battery_voltage);
	bq2415x_regulator_unregister(bq, battery_regulation_voltage);
	bq2415x_regulator_unregister(bq, charge_current_sense_voltage);
	bq2415x_regulator_unregister(bq, termination_current_sense_voltage);*/
}

#undef bq2415x_regulator_register
#undef bq2415x_regulator_unregister

/* power supply */

static enum power_supply_property bq2415x_power_supply_props[] = {
	/* TODO */
	POWER_SUPPLY_PROP_STATUS,
};

static void bq2415x_power_supply_work(struct work_struct *work)
{
	struct bq2415x_device *bq = container_of(work, struct bq2415x_device, work.work);
	int ret;

	dev_info(bq->dev, "bq2415x_power_supply_work\n");

	if (bq->watchdog != 1)
		return;

	ret = bq2415x_exec_command(bq, BQ2415X_WATCHDOG_RESET);
	if (ret < 0)
		bq->watchdog = ret;

	if (bq->watchdog != 1)
		return;

	/* TODO charge */

	schedule_delayed_work(&bq->work, BQ2415X_WATCHDOG_TIMEOUT * HZ);
}

static void bq2415x_power_supply_update_watchdog(struct bq2415x_device *bq, int auto_enable)
{
	if (auto_enable && bq->watchdog == 1)
		return;

	if (!auto_enable && bq->watchdog == 0)
		return;

	if (auto_enable) {
		bq->watchdog = 1;
		schedule_delayed_work(&bq->work, BQ2415X_WATCHDOG_TIMEOUT * HZ);
		bq2415x_exec_command(bq, BQ2415X_WATCHDOG_RESET);
	} else {
		bq->watchdog = 0;
		cancel_delayed_work_sync(&bq->work);
	}
}

static int bq2415x_power_supply_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val)
{
	struct bq2415x_device *bq = container_of(psy, struct bq2415x_device, charger);
	/* TODO */
	return -EINVAL;
}

static int bq2415x_power_supply_init(struct bq2415x_device *bq)
{
	int ret;

	bq->charger.name = bq->name;
	bq->charger.type = POWER_SUPPLY_TYPE_USB;
	bq->charger.properties = bq2415x_power_supply_props;
	bq->charger.num_properties = ARRAY_SIZE(bq2415x_power_supply_props);
	bq->charger.get_property = bq2415x_power_supply_get_property;

	ret = power_supply_register(bq->dev, &bq->charger);
	if (ret)
		return ret;

	INIT_DELAYED_WORK(&bq->work, bq2415x_power_supply_work);

	bq2415x_power_supply_update_watchdog(bq, 1);
	return ret;
}

static void bq2415x_power_supply_exit(struct bq2415x_device *bq)
{
	bq->watchdog = 0;
	cancel_delayed_work_sync(&bq->work);
	power_supply_unregister(&bq->charger);
}

/* sysfs files */

static ssize_t bq2415x_sysfs_show_status(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct bq2415x_device *bq = container_of(psy, struct bq2415x_device, charger);
	enum bq2415x_command command;
	int ret;

	if (strcmp(attr->attr.name, "otg_status") == 0)
		command = BQ2415X_OTG_STATUS;
	else if (strcmp(attr->attr.name, "charge_status") == 0)
		command = BQ2415X_CHARGE_STATUS;
	else if (strcmp(attr->attr.name, "boost_status") == 0)
		command = BQ2415X_BOOST_STATUS;
	else if (strcmp(attr->attr.name, "fault_status") == 0)
		command = BQ2415X_FAULT_STATUS;
	else
		return -EINVAL;

	ret = bq2415x_exec_command(bq, command);
	if (ret < 0)
		return ret;
	else
		return sprintf(buf, "%d\n", ret);
}

static ssize_t bq2415x_sysfs_set_watchdog(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct bq2415x_device *bq = container_of(psy, struct bq2415x_device, charger);
	int ret = 0;

	if (strncmp(buf, "auto", 4) == 0)
		bq2415x_power_supply_update_watchdog(bq, 1);
	else if (strncmp(buf, "off", 3) == 0)
		bq2415x_power_supply_update_watchdog(bq, 0);
	else
		ret = bq2415x_exec_command(bq, BQ2415X_WATCHDOG_RESET);

	if (ret < 0)
		return ret;
	else
		return count;
}

static ssize_t bq2415x_sysfs_show_watchdog(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct power_supply *psy = dev_get_drvdata(dev);
	struct bq2415x_device *bq = container_of(psy, struct bq2415x_device, charger);

	switch (bq->watchdog) {
		case 1: return sprintf(buf, "auto\n");
		case 0: return sprintf(buf, "off\n");
		default: return sprintf(buf, "error %d\n", bq->watchdog);
	}
}

/* TODO: Add other sysfs entries */

static DEVICE_ATTR(watchdog, S_IWUSR | S_IRUGO, bq2415x_sysfs_show_watchdog, bq2415x_sysfs_set_watchdog);
static DEVICE_ATTR(otg_status, S_IRUGO, bq2415x_sysfs_show_status, NULL);
static DEVICE_ATTR(charge_status, S_IRUGO, bq2415x_sysfs_show_status, NULL);
static DEVICE_ATTR(boost_status, S_IRUGO, bq2415x_sysfs_show_status, NULL);
static DEVICE_ATTR(fault_status, S_IRUGO, bq2415x_sysfs_show_status, NULL);

static struct attribute *bq2415x_sysfs_attributes[] = {
	&dev_attr_watchdog.attr,
	&dev_attr_otg_status.attr,
	&dev_attr_charge_status.attr,
	&dev_attr_boost_status.attr,
	&dev_attr_fault_status.attr,
	NULL,
};

static const struct attribute_group bq2415x_sysfs_attr_group = {
	.attrs = bq2415x_sysfs_attributes,
};

static int bq2415x_sysfs_init(struct bq2415x_device *bq)
{
	return sysfs_create_group(&bq->charger.dev->kobj, &bq2415x_sysfs_attr_group);
}

static void bq2415x_sysfs_exit(struct bq2415x_device *bq)
{
	sysfs_remove_group(&bq->charger.dev->kobj, &bq2415x_sysfs_attr_group);
}

/* charger led device on STAT_PIN */

static void bq2415x_led_set(struct led_classdev *led_cdev, enum led_brightness value)
{
	struct i2c_client *client = to_i2c_client(led_cdev->dev->parent);
	struct bq2415x_device *bq = i2c_get_clientdata(client);

	if (value)
		bq2415x_exec_command(bq, BQ2415X_STAT_PIN_ENABLE);
	else
		bq2415x_exec_command(bq, BQ2415X_STAT_PIN_DISABLE);
}

static enum led_brightness bq2415x_led_get(struct led_classdev *led_cdev)
{
	struct i2c_client *client = to_i2c_client(led_cdev->dev->parent);
	struct bq2415x_device *bq = i2c_get_clientdata(client);

	if (bq2415x_exec_command(bq, BQ2415X_STAT_PIN_STATUS) > 0)
		return LED_FULL;
	else
		return LED_OFF;
}

static int bq2415x_led_init(struct bq2415x_device *bq)
{
	bq->led.name = bq->name;
	bq->led.brightness_set = bq2415x_led_set;
	bq->led.brightness_get = bq2415x_led_get;
	return led_classdev_register(bq->dev, &bq->led);
}

static void bq2415x_led_exit(struct bq2415x_device *bq)
{
	led_classdev_unregister(&bq->led);
}

/* bq2415x register */

static int bq2415x_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	int ret;
	int num;
	char *name;
	struct bq2415x_device *bq;

	if (!client->dev.platform_data) {
		dev_err(&client->dev, "platform data not set\n");
		return -ENODEV;
	}

	/* Get new ID for the new device */
	ret = idr_pre_get(&bq2415x_id, GFP_KERNEL);
	if (ret == 0)
		return -ENOMEM;

	mutex_lock(&bq2415x_mutex);
	ret = idr_get_new(&bq2415x_id, client, &num);
	mutex_unlock(&bq2415x_mutex);

	if (ret < 0)
		return ret;

	name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
	if (!name) {
		dev_err(&client->dev, "failed to allocate device name\n");
		ret = -ENOMEM;
		goto error_1;
	}

	bq = kzalloc(sizeof(*bq), GFP_KERNEL);
	if (!bq) {
		dev_err(&client->dev, "failed to allocate device data\n");
		ret = -ENOMEM;
		goto error_2;
	}

	i2c_set_clientdata(client, bq);

	bq->id = num;
	bq->dev = &client->dev;
	bq->chip = id->driver_data;
	bq->name = name;
	bq->platform_data = client->dev.platform_data;
	bq->watchdog = 0;

	bq2415x_reset_chip(bq);

	ret = bq2415x_regulator_init(bq);
	if (ret) {
		dev_err(bq->dev, "failed to register regulators: %d\n", ret);
		goto error_3;
	}

	ret = bq2415x_led_init(bq);
	if (ret) {
		dev_err(bq->dev, "failed to register led device: %d\n", ret);
		goto error_4;
	}

	ret = bq2415x_power_supply_init(bq);
	if (ret) {
		dev_err(bq->dev, "failed to register power supply: %d\n", ret);
		goto error_5;
	}

	ret = bq2415x_sysfs_init(bq);
	if (ret) {
		dev_err(bq->dev, "failed to create sysfs entries: %d\n", ret);
		goto error_6;
	}

	bq2415x_set_defaults(bq);

	dev_info(bq->dev, "driver registred\n");
	return 0;

/*error_7:*/
	bq2415x_sysfs_exit(bq);
error_6:
	bq2415x_power_supply_exit(bq);
error_5:
	bq2415x_led_exit(bq);
error_4:
	bq2415x_regulator_exit(bq);
error_3:
	kfree(bq);
error_2:
	kfree(name);
error_1:
	mutex_lock(&bq2415x_mutex);
	idr_remove(&bq2415x_id, num);
	mutex_unlock(&bq2415x_mutex);

	return ret;
}

/* bq2415x unregister */

static int bq2415x_remove(struct i2c_client *client)
{
	struct bq2415x_device *bq = i2c_get_clientdata(client);

	bq2415x_sysfs_exit(bq);
	bq2415x_power_supply_exit(bq);
	bq2415x_led_exit(bq);
	bq2415x_regulator_exit(bq);

	bq2415x_reset_chip(bq);

	mutex_lock(&bq2415x_mutex);
	idr_remove(&bq2415x_id, bq->id);
	mutex_unlock(&bq2415x_mutex);

	dev_info(bq->dev, "driver unregistred\n");

	kfree(bq->name);
	kfree(bq);

	return 0;
}

static const struct i2c_device_id bq2415x_i2c_id_table[] = {
	{ "bq2415x", BQUNKNOWN },
	{ "bq24150", BQ24150 },
	{ "bq24150a", BQ24150A },
	{ "bq24151", BQ24151 },
	{ "bq24151a", BQ24151A },
	{ "bq24152", BQ24152 },
	{ "bq24153", BQ24153 },
	{ "bq24153a", BQ24153A },
	{ "bq24155", BQ24155 },
	{ "bq24156", BQ24156 },
	{ "bq24156a", BQ24156A },
	{ "bq24158", BQ24158 },
	{},
};
MODULE_DEVICE_TABLE(i2c, bq2415x_i2c_id_table);

static struct i2c_driver bq2415x_driver = {
	.driver = {
		.name = "bq2415x-charger",
	},
	.probe = bq2415x_probe,
	.remove = bq2415x_remove,
	.id_table = bq2415x_i2c_id_table,
};

/* BEGIN: Temporary RX51 hack TODO: move to board-rx51.c */
static struct bq2415x_platform_data rx51_platform_data = {
	.current_limit = 100, /* mA */
	.weak_battery_voltage = 3400, /* mV */
	.battery_regulation_voltage = 4200, /* mV */
	.charge_current_sense_voltage = -1, /* TODO */
	.termination_current_sense_voltage = -1, /* TODO */
};
static struct i2c_board_info rx51_board_info = {
	I2C_BOARD_INFO("bq24150", 0x6b),
	.platform_data = &rx51_platform_data,
};
static struct i2c_client *client;
/* END */

static int __init bq2415x_init(void)
{
	/* BEGIN: Temporary RX51 hack TODO: move to board-rx51.c */
	client = i2c_new_device(i2c_get_adapter(2), &rx51_board_info);
	/* END */

	return i2c_add_driver(&bq2415x_driver);
}
module_init(bq2415x_init);

static void __exit bq2415x_exit(void)
{
	/* BEGIN: Temporary RX51 hack TODO: move to board-rx51.c */
	i2c_unregister_device(client);
	/* END */

	i2c_del_driver(&bq2415x_driver);
}
module_exit(bq2415x_exit);

MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
MODULE_DESCRIPTION("bq2415x charger driver");
MODULE_LICENSE("GPL");