/*

   * bq2415x charger driver
   *

   * Copyright (C) 2011-2013  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.
   *

   * 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

   * http://www.ti.com/product/bq24157s
   * http://www.ti.com/product/bq24158

   */

  #include <linux/kernel.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/power_supply.h>
  #include <linux/idr.h>
  #include <linux/i2c.h>
  #include <linux/slab.h>

  #include <linux/acpi.h>

  
  #include <linux/power/bq2415x_charger.h>
  
  /* timeout for resetting chip timer */
  #define BQ2415X_TIMER_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		3
  #define BQ2415X_MASK_REVISION		(BIT(0)|BIT(1)|BIT(2))
  #define BQ2415X_SHIFT_REVISION		0
  
  /* current register */
  #define BQ2415X_MASK_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
  
  
  enum bq2415x_command {
  	BQ2415X_TIMER_RESET,
  	BQ2415X_OTG_STATUS,
  	BQ2415X_STAT_PIN_STATUS,
  	BQ2415X_STAT_PIN_ENABLE,
  	BQ2415X_STAT_PIN_DISABLE,
  	BQ2415X_CHARGE_STATUS,
  	BQ2415X_BOOST_STATUS,
  	BQ2415X_FAULT_STATUS,
  
  	BQ2415X_CHARGE_TERMINATION_STATUS,
  	BQ2415X_CHARGE_TERMINATION_ENABLE,
  	BQ2415X_CHARGE_TERMINATION_DISABLE,
  	BQ2415X_CHARGER_STATUS,
  	BQ2415X_CHARGER_ENABLE,
  	BQ2415X_CHARGER_DISABLE,
  	BQ2415X_HIGH_IMPEDANCE_STATUS,
  	BQ2415X_HIGH_IMPEDANCE_ENABLE,
  	BQ2415X_HIGH_IMPEDANCE_DISABLE,
  	BQ2415X_BOOST_MODE_STATUS,
  	BQ2415X_BOOST_MODE_ENABLE,
  	BQ2415X_BOOST_MODE_DISABLE,
  
  	BQ2415X_OTG_LEVEL,
  	BQ2415X_OTG_ACTIVATE_HIGH,
  	BQ2415X_OTG_ACTIVATE_LOW,
  	BQ2415X_OTG_PIN_STATUS,
  	BQ2415X_OTG_PIN_ENABLE,
  	BQ2415X_OTG_PIN_DISABLE,
  
  	BQ2415X_VENDER_CODE,
  	BQ2415X_PART_NUMBER,
  	BQ2415X_REVISION,
  };
  
  enum bq2415x_chip {
  	BQUNKNOWN,
  	BQ24150,
  	BQ24150A,
  	BQ24151,
  	BQ24151A,
  	BQ24152,
  	BQ24153,
  	BQ24153A,
  	BQ24155,
  	BQ24156,
  	BQ24156A,

  	BQ24157S,

  	BQ24158,
  };
  
  static char *bq2415x_chip_name[] = {
  	"unknown",
  	"bq24150",
  	"bq24150a",
  	"bq24151",
  	"bq24151a",
  	"bq24152",
  	"bq24153",
  	"bq24153a",
  	"bq24155",
  	"bq24156",
  	"bq24156a",

  	"bq24157s",

  	"bq24158",
  };
  
  struct bq2415x_device {
  	struct device *dev;
  	struct bq2415x_platform_data init_data;

  	struct power_supply *charger;
  	struct power_supply_desc charger_desc;

  	struct delayed_work work;

  	struct device_node *notify_node;

  	struct notifier_block nb;

  	enum bq2415x_mode reported_mode;/* mode reported by hook function */

  	enum bq2415x_mode mode;		/* currently configured mode */

  	enum bq2415x_chip chip;
  	const char *timer_error;
  	char *model;
  	char *name;
  	int autotimer;	/* 1 - if driver automatically reset timer, 0 - not */
  	int automode;	/* 1 - enabled, 0 - disabled; -1 - not supported */
  	int id;
  };
  
  /* each registered chip must have unique id */
  static DEFINE_IDR(bq2415x_id);
  
  static DEFINE_MUTEX(bq2415x_id_mutex);
  static DEFINE_MUTEX(bq2415x_timer_mutex);
  static DEFINE_MUTEX(bq2415x_i2c_mutex);
  
  /**** i2c read functions ****/
  
  /* read value from register */
  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;
  
  	if (!client->adapter)
  		return -ENODEV;
  
  	msg[0].addr = client->addr;
  	msg[0].flags = 0;
  	msg[0].buf = ®
  	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_i2c_mutex);
  	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  	mutex_unlock(&bq2415x_i2c_mutex);
  
  	if (ret < 0)
  		return ret;
  
  	return val;
  }
  
  /* read value from register, apply mask and right shift it */
  static int bq2415x_i2c_read_mask(struct bq2415x_device *bq, u8 reg,

  				 u8 mask, u8 shift)

  {
  	int ret;
  
  	if (shift > 8)
  		return -EINVAL;
  
  	ret = bq2415x_i2c_read(bq, reg);
  	if (ret < 0)
  		return ret;

  	return (ret & mask) >> shift;

  }
  
  /* read value from register and return one specified bit */
  static int bq2415x_i2c_read_bit(struct bq2415x_device *bq, u8 reg, u8 bit)
  {
  	if (bit > 8)
  		return -EINVAL;

  	return bq2415x_i2c_read_mask(bq, reg, BIT(bit), bit);

  }
  
  /**** i2c write functions ****/
  
  /* write value to register */
  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;
  
  	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_i2c_mutex);
  	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
  	mutex_unlock(&bq2415x_i2c_mutex);
  
  	/* i2c_transfer returns number of messages transferred */
  	if (ret < 0)
  		return ret;
  	else if (ret != 1)
  		return -EIO;
  
  	return 0;
  }
  
  /* read value from register, change it with mask left shifted and write back */
  static int bq2415x_i2c_write_mask(struct bq2415x_device *bq, u8 reg, u8 val,

  				  u8 mask, u8 shift)

  {
  	int ret;
  
  	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);
  }
  
  /* change only one bit in register */
  static int bq2415x_i2c_write_bit(struct bq2415x_device *bq, u8 reg,

  				 bool val, u8 bit)

  {
  	if (bit > 8)
  		return -EINVAL;

  	return bq2415x_i2c_write_mask(bq, reg, val, BIT(bit), bit);

  }
  
  /**** global functions ****/
  
  /* exec command function */
  static int bq2415x_exec_command(struct bq2415x_device *bq,
  				enum bq2415x_command command)
  {
  	int ret;

  	switch (command) {
  	case BQ2415X_TIMER_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_TERMINATION_STATUS:
  		return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL,
  				BQ2415X_BIT_TE);
  	case BQ2415X_CHARGE_TERMINATION_ENABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				1, BQ2415X_BIT_TE);
  	case BQ2415X_CHARGE_TERMINATION_DISABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				0, BQ2415X_BIT_TE);
  	case BQ2415X_CHARGER_STATUS:
  		ret = bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL,
  			BQ2415X_BIT_CE);
  		if (ret < 0)
  			return ret;

  		return ret > 0 ? 0 : 1;

  	case BQ2415X_CHARGER_ENABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				0, BQ2415X_BIT_CE);
  	case BQ2415X_CHARGER_DISABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				1, 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_BOOST_MODE_STATUS:
  		return bq2415x_i2c_read_bit(bq, BQ2415X_REG_CONTROL,
  				BQ2415X_BIT_OPA_MODE);
  	case BQ2415X_BOOST_MODE_ENABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				1, BQ2415X_BIT_OPA_MODE);
  	case BQ2415X_BOOST_MODE_DISABLE:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_CONTROL,
  				0, BQ2415X_BIT_OPA_MODE);
  
  	case BQ2415X_OTG_LEVEL:
  		return bq2415x_i2c_read_bit(bq, BQ2415X_REG_VOLTAGE,
  				BQ2415X_BIT_OTG_PL);
  	case BQ2415X_OTG_ACTIVATE_HIGH:
  		return bq2415x_i2c_write_bit(bq, BQ2415X_REG_VOLTAGE,
  				1, BQ2415X_BIT_OTG_PL);
  	case BQ2415X_OTG_ACTIVATE_LOW:
  		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);

  	}

  	return -EINVAL;

  }
  
  /* detect chip type */
  static 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;
  
  	switch (client->addr) {
  	case 0x6b:
  		switch (ret) {
  		case 0:
  			if (bq->chip == BQ24151A)
  				return bq->chip;

  			return BQ24151;

  		case 1:
  			if (bq->chip == BQ24150A ||
  				bq->chip == BQ24152 ||
  				bq->chip == BQ24155)
  				return bq->chip;

  			return BQ24150;

  		case 2:
  			if (bq->chip == BQ24153A)
  				return bq->chip;

  			return BQ24153;

  		default:
  			return BQUNKNOWN;
  		}
  		break;
  
  	case 0x6a:
  		switch (ret) {
  		case 0:
  			if (bq->chip == BQ24156A)
  				return bq->chip;

  			return BQ24156;

  		case 2:

  			if (bq->chip == BQ24157S)
  				return bq->chip;

  			return BQ24158;
  		default:
  			return BQUNKNOWN;
  		}
  		break;
  	}
  
  	return BQUNKNOWN;
  }
  
  /* detect chip revision */
  static int bq2415x_detect_revision(struct bq2415x_device *bq)
  {
  	int ret = bq2415x_exec_command(bq, BQ2415X_REVISION);
  	int chip = bq2415x_detect_chip(bq);

  	if (ret < 0 || chip < 0)
  		return -1;
  
  	switch (chip) {
  	case BQ24150:
  	case BQ24150A:
  	case BQ24151:
  	case BQ24151A:
  	case BQ24152:
  		if (ret >= 0 && ret <= 3)
  			return ret;

  		return -1;

  	case BQ24153:
  	case BQ24153A:
  	case BQ24156:
  	case BQ24156A:

  	case BQ24157S:

  	case BQ24158:
  		if (ret == 3)
  			return 0;
  		else if (ret == 1)
  			return 1;

  		return -1;

  	case BQ24155:
  		if (ret == 3)
  			return 3;

  		return -1;

  	case BQUNKNOWN:
  		return -1;
  	}
  
  	return -1;
  }
  
  /* return chip vender code */
  static int bq2415x_get_vender_code(struct bq2415x_device *bq)
  {

  	int ret;
  
  	ret = bq2415x_exec_command(bq, BQ2415X_VENDER_CODE);

  	if (ret < 0)
  		return 0;

  
  	/* convert to binary */
  	return (ret & 0x1) +
  	       ((ret >> 1) & 0x1) * 10 +
  	       ((ret >> 2) & 0x1) * 100;

  }
  
  /* reset all chip registers to default state */
  static 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);
  	bq->timer_error = NULL;
  }
  
  /**** properties functions ****/
  
  /* set current limit in mA */
  static int bq2415x_set_current_limit(struct bq2415x_device *bq, int mA)
  {
  	int val;

  	if (mA <= 100)
  		val = 0;
  	else if (mA <= 500)
  		val = 1;
  	else if (mA <= 800)
  		val = 2;
  	else
  		val = 3;

  	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CONTROL, val,
  			BQ2415X_MASK_LIMIT, BQ2415X_SHIFT_LIMIT);
  }
  
  /* get current limit in mA */
  static int bq2415x_get_current_limit(struct bq2415x_device *bq)
  {

  	int ret;
  
  	ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CONTROL,

  			BQ2415X_MASK_LIMIT, BQ2415X_SHIFT_LIMIT);
  	if (ret < 0)
  		return ret;
  	else if (ret == 0)
  		return 100;
  	else if (ret == 1)
  		return 500;
  	else if (ret == 2)
  		return 800;
  	else if (ret == 3)
  		return 1800;

  	return -EINVAL;

  }
  
  /* set weak battery voltage in mV */
  static int bq2415x_set_weak_battery_voltage(struct bq2415x_device *bq, int mV)
  {

  	int val;

  
  	/* round to 100mV */

  	if (mV <= 3400 + 50)
  		val = 0;
  	else if (mV <= 3500 + 50)
  		val = 1;
  	else if (mV <= 3600 + 50)
  		val = 2;
  	else
  		val = 3;

  	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CONTROL, val,
  			BQ2415X_MASK_VLOWV, BQ2415X_SHIFT_VLOWV);
  }
  
  /* get weak battery voltage in mV */
  static int bq2415x_get_weak_battery_voltage(struct bq2415x_device *bq)
  {

  	int ret;
  
  	ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CONTROL,

  			BQ2415X_MASK_VLOWV, BQ2415X_SHIFT_VLOWV);
  	if (ret < 0)
  		return ret;

  	return 100 * (34 + ret);

  }
  
  /* set battery regulation voltage in mV */
  static int bq2415x_set_battery_regulation_voltage(struct bq2415x_device *bq,

  						  int mV)

  {
  	int val = (mV/10 - 350) / 2;

  	/*
  	 * According to datasheet, maximum battery regulation voltage is
  	 * 4440mV which is b101111 = 47.
  	 */

  	if (val < 0)
  		val = 0;

  	else if (val > 47)

  		return -EINVAL;
  
  	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_VOLTAGE, val,
  			BQ2415X_MASK_VO, BQ2415X_SHIFT_VO);
  }
  
  /* get battery regulation voltage in mV */
  static 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;

  	return 10 * (350 + 2*ret);

  }
  
  /* set charge current in mA (platform data must provide resistor sense) */
  static int bq2415x_set_charge_current(struct bq2415x_device *bq, int mA)
  {
  	int val;

  	if (bq->init_data.resistor_sense <= 0)

  		return -EINVAL;

  
  	val = (mA * bq->init_data.resistor_sense - 37400) / 6800;

  	if (val < 0)
  		val = 0;
  	else if (val > 7)
  		val = 7;
  
  	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CURRENT, val,
  			BQ2415X_MASK_VI_CHRG | BQ2415X_MASK_RESET,
  			BQ2415X_SHIFT_VI_CHRG);
  }
  
  /* get charge current in mA (platform data must provide resistor sense) */
  static int bq2415x_get_charge_current(struct bq2415x_device *bq)
  {
  	int ret;

  	if (bq->init_data.resistor_sense <= 0)

  		return -EINVAL;

  
  	ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CURRENT,
  			BQ2415X_MASK_VI_CHRG, BQ2415X_SHIFT_VI_CHRG);
  	if (ret < 0)
  		return ret;

  	return (37400 + 6800*ret) / bq->init_data.resistor_sense;

  }
  
  /* set termination current in mA (platform data must provide resistor sense) */
  static int bq2415x_set_termination_current(struct bq2415x_device *bq, int mA)
  {
  	int val;

  	if (bq->init_data.resistor_sense <= 0)

  		return -EINVAL;

  
  	val = (mA * bq->init_data.resistor_sense - 3400) / 3400;

  	if (val < 0)
  		val = 0;
  	else if (val > 7)
  		val = 7;
  
  	return bq2415x_i2c_write_mask(bq, BQ2415X_REG_CURRENT, val,
  			BQ2415X_MASK_VI_TERM | BQ2415X_MASK_RESET,
  			BQ2415X_SHIFT_VI_TERM);
  }
  
  /* get termination current in mA (platform data must provide resistor sense) */
  static int bq2415x_get_termination_current(struct bq2415x_device *bq)
  {
  	int ret;

  	if (bq->init_data.resistor_sense <= 0)

  		return -EINVAL;

  
  	ret = bq2415x_i2c_read_mask(bq, BQ2415X_REG_CURRENT,
  			BQ2415X_MASK_VI_TERM, BQ2415X_SHIFT_VI_TERM);
  	if (ret < 0)
  		return ret;

  	return (3400 + 3400*ret) / bq->init_data.resistor_sense;

  }
  
  /* set default value of property */
  #define bq2415x_set_default_value(bq, prop) \
  	do { \
  		int ret = 0; \
  		if (bq->init_data.prop != -1) \
  			ret = bq2415x_set_##prop(bq, bq->init_data.prop); \
  		if (ret < 0) \
  			return ret; \
  	} while (0)
  
  /* set default values of all properties */
  static int bq2415x_set_defaults(struct bq2415x_device *bq)
  {
  	bq2415x_exec_command(bq, BQ2415X_BOOST_MODE_DISABLE);
  	bq2415x_exec_command(bq, BQ2415X_CHARGER_DISABLE);
  	bq2415x_exec_command(bq, BQ2415X_CHARGE_TERMINATION_DISABLE);

  	bq2415x_set_default_value(bq, current_limit);
  	bq2415x_set_default_value(bq, weak_battery_voltage);
  	bq2415x_set_default_value(bq, battery_regulation_voltage);

  	if (bq->init_data.resistor_sense > 0) {
  		bq2415x_set_default_value(bq, charge_current);
  		bq2415x_set_default_value(bq, termination_current);
  		bq2415x_exec_command(bq, BQ2415X_CHARGE_TERMINATION_ENABLE);
  	}

  	bq2415x_exec_command(bq, BQ2415X_CHARGER_ENABLE);
  	return 0;
  }
  
  /**** charger mode functions ****/
  
  /* set charger mode */
  static int bq2415x_set_mode(struct bq2415x_device *bq, enum bq2415x_mode mode)
  {
  	int ret = 0;
  	int charger = 0;
  	int boost = 0;

  	if (mode == BQ2415X_MODE_BOOST)
  		boost = 1;

  	else if (mode != BQ2415X_MODE_OFF)
  		charger = 1;

  
  	if (!charger)
  		ret = bq2415x_exec_command(bq, BQ2415X_CHARGER_DISABLE);
  
  	if (!boost)
  		ret = bq2415x_exec_command(bq, BQ2415X_BOOST_MODE_DISABLE);
  
  	if (ret < 0)
  		return ret;
  
  	switch (mode) {

  	case BQ2415X_MODE_OFF:
  		dev_dbg(bq->dev, "changing mode to: Offline
  ");
  		ret = bq2415x_set_current_limit(bq, 100);
  		break;

  	case BQ2415X_MODE_NONE:
  		dev_dbg(bq->dev, "changing mode to: N/A
  ");
  		ret = bq2415x_set_current_limit(bq, 100);
  		break;
  	case BQ2415X_MODE_HOST_CHARGER:
  		dev_dbg(bq->dev, "changing mode to: Host/HUB charger
  ");
  		ret = bq2415x_set_current_limit(bq, 500);
  		break;
  	case BQ2415X_MODE_DEDICATED_CHARGER:
  		dev_dbg(bq->dev, "changing mode to: Dedicated charger
  ");
  		ret = bq2415x_set_current_limit(bq, 1800);
  		break;
  	case BQ2415X_MODE_BOOST: /* Boost mode */
  		dev_dbg(bq->dev, "changing mode to: Boost
  ");
  		ret = bq2415x_set_current_limit(bq, 100);
  		break;
  	}
  
  	if (ret < 0)
  		return ret;
  
  	if (charger)
  		ret = bq2415x_exec_command(bq, BQ2415X_CHARGER_ENABLE);
  	else if (boost)
  		ret = bq2415x_exec_command(bq, BQ2415X_BOOST_MODE_ENABLE);
  
  	if (ret < 0)
  		return ret;
  
  	bq2415x_set_default_value(bq, weak_battery_voltage);
  	bq2415x_set_default_value(bq, battery_regulation_voltage);
  
  	bq->mode = mode;

  	sysfs_notify(&bq->charger->dev.kobj, NULL, "mode");

  
  	return 0;
  
  }

  static bool bq2415x_update_reported_mode(struct bq2415x_device *bq, int mA)
  {
  	enum bq2415x_mode mode;
  
  	if (mA == 0)
  		mode = BQ2415X_MODE_OFF;
  	else if (mA < 500)
  		mode = BQ2415X_MODE_NONE;
  	else if (mA < 1800)
  		mode = BQ2415X_MODE_HOST_CHARGER;
  	else
  		mode = BQ2415X_MODE_DEDICATED_CHARGER;
  
  	if (bq->reported_mode == mode)
  		return false;
  
  	bq->reported_mode = mode;
  	return true;
  }

  static int bq2415x_notifier_call(struct notifier_block *nb,
  		unsigned long val, void *v)

  {

  	struct bq2415x_device *bq =
  		container_of(nb, struct bq2415x_device, nb);
  	struct power_supply *psy = v;

  	union power_supply_propval prop;
  	int ret;

  	if (val != PSY_EVENT_PROP_CHANGED)
  		return NOTIFY_OK;

  	/* Ignore event if it was not send by notify_node/notify_device */
  	if (bq->notify_node) {
  		if (!psy->dev.parent ||
  		    psy->dev.parent->of_node != bq->notify_node)
  			return NOTIFY_OK;
  	} else if (bq->init_data.notify_device) {
  		if (strcmp(psy->desc->name, bq->init_data.notify_device) != 0)
  			return NOTIFY_OK;
  	}

  
  	dev_dbg(bq->dev, "notifier call was called
  ");

  	ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_CURRENT_MAX,
  			&prop);

  	if (ret != 0)
  		return NOTIFY_OK;

  	if (!bq2415x_update_reported_mode(bq, prop.intval))

  		return NOTIFY_OK;

  	/* if automode is not enabled do not tell about reported_mode */
  	if (bq->automode < 1)

  		return NOTIFY_OK;

  	schedule_delayed_work(&bq->work, 0);

  	return NOTIFY_OK;

  }
  
  /**** timer functions ****/
  
  /* enable/disable auto resetting chip timer */
  static void bq2415x_set_autotimer(struct bq2415x_device *bq, int state)
  {
  	mutex_lock(&bq2415x_timer_mutex);
  
  	if (bq->autotimer == state) {
  		mutex_unlock(&bq2415x_timer_mutex);
  		return;
  	}
  
  	bq->autotimer = state;
  
  	if (state) {
  		schedule_delayed_work(&bq->work, BQ2415X_TIMER_TIMEOUT * HZ);
  		bq2415x_exec_command(bq, BQ2415X_TIMER_RESET);
  		bq->timer_error = NULL;
  	} else {
  		cancel_delayed_work_sync(&bq->work);
  	}
  
  	mutex_unlock(&bq2415x_timer_mutex);
  }
  
  /* called by bq2415x_timer_work on timer error */
  static void bq2415x_timer_error(struct bq2415x_device *bq, const char *msg)
  {
  	bq->timer_error = msg;

  	sysfs_notify(&bq->charger->dev.kobj, NULL, "timer");

  	dev_err(bq->dev, "%s
  ", msg);
  	if (bq->automode > 0)
  		bq->automode = 0;

  	bq2415x_set_mode(bq, BQ2415X_MODE_OFF);

  	bq2415x_set_autotimer(bq, 0);
  }
  
  /* delayed work function for auto resetting chip timer */
  static void bq2415x_timer_work(struct work_struct *work)
  {
  	struct bq2415x_device *bq = container_of(work, struct bq2415x_device,

  						 work.work);
  	int ret;
  	int error;
  	int boost;

  	if (bq->automode > 0 && (bq->reported_mode != bq->mode)) {

  		sysfs_notify(&bq->charger->dev.kobj, NULL, "reported_mode");

  		bq2415x_set_mode(bq, bq->reported_mode);
  	}

  	if (!bq->autotimer)
  		return;
  
  	ret = bq2415x_exec_command(bq, BQ2415X_TIMER_RESET);
  	if (ret < 0) {
  		bq2415x_timer_error(bq, "Resetting timer failed");
  		return;
  	}
  
  	boost = bq2415x_exec_command(bq, BQ2415X_BOOST_MODE_STATUS);
  	if (boost < 0) {
  		bq2415x_timer_error(bq, "Unknown error");
  		return;
  	}
  
  	error = bq2415x_exec_command(bq, BQ2415X_FAULT_STATUS);
  	if (error < 0) {
  		bq2415x_timer_error(bq, "Unknown error");
  		return;
  	}
  
  	if (boost) {
  		switch (error) {
  		/* Non fatal errors, chip is OK */
  		case 0: /* No error */
  			break;
  		case 6: /* Timer expired */
  			dev_err(bq->dev, "Timer expired
  ");
  			break;
  		case 3: /* Battery voltage too low */
  			dev_err(bq->dev, "Battery voltage to low
  ");
  			break;
  
  		/* Fatal errors, disable and reset chip */
  		case 1: /* Overvoltage protection (chip fried) */
  			bq2415x_timer_error(bq,
  				"Overvoltage protection (chip fried)");
  			return;
  		case 2: /* Overload */
  			bq2415x_timer_error(bq, "Overload");
  			return;
  		case 4: /* Battery overvoltage protection */
  			bq2415x_timer_error(bq,
  				"Battery overvoltage protection");
  			return;
  		case 5: /* Thermal shutdown (too hot) */
  			bq2415x_timer_error(bq,
  					"Thermal shutdown (too hot)");
  			return;
  		case 7: /* N/A */
  			bq2415x_timer_error(bq, "Unknown error");
  			return;
  		}
  	} else {
  		switch (error) {
  		/* Non fatal errors, chip is OK */
  		case 0: /* No error */
  			break;
  		case 2: /* Sleep mode */
  			dev_err(bq->dev, "Sleep mode
  ");
  			break;
  		case 3: /* Poor input source */
  			dev_err(bq->dev, "Poor input source
  ");
  			break;
  		case 6: /* Timer expired */
  			dev_err(bq->dev, "Timer expired
  ");
  			break;
  		case 7: /* No battery */
  			dev_err(bq->dev, "No battery
  ");
  			break;
  
  		/* Fatal errors, disable and reset chip */
  		case 1: /* Overvoltage protection (chip fried) */
  			bq2415x_timer_error(bq,
  				"Overvoltage protection (chip fried)");
  			return;
  		case 4: /* Battery overvoltage protection */
  			bq2415x_timer_error(bq,
  				"Battery overvoltage protection");
  			return;
  		case 5: /* Thermal shutdown (too hot) */
  			bq2415x_timer_error(bq,
  				"Thermal shutdown (too hot)");
  			return;
  		}
  	}
  
  	schedule_delayed_work(&bq->work, BQ2415X_TIMER_TIMEOUT * HZ);
  }
  
  /**** power supply interface code ****/
  
  static enum power_supply_property bq2415x_power_supply_props[] = {
  	/* TODO: maybe add more power supply properties */
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_MODEL_NAME,
  };
  
  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 = power_supply_get_drvdata(psy);

  	int ret;
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_STATUS:
  		ret = bq2415x_exec_command(bq, BQ2415X_CHARGE_STATUS);
  		if (ret < 0)
  			return ret;
  		else if (ret == 0) /* Ready */
  			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
  		else if (ret == 1) /* Charge in progress */
  			val->intval = POWER_SUPPLY_STATUS_CHARGING;
  		else if (ret == 2) /* Charge done */
  			val->intval = POWER_SUPPLY_STATUS_FULL;
  		else
  			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
  		break;
  	case POWER_SUPPLY_PROP_MODEL_NAME:
  		val->strval = bq->model;
  		break;
  	default:
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static int bq2415x_power_supply_init(struct bq2415x_device *bq)
  {
  	int ret;
  	int chip;
  	char revstr[8];

  	struct power_supply_config psy_cfg = { .drv_data = bq, };

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

  
  	ret = bq2415x_detect_chip(bq);
  	if (ret < 0)
  		chip = BQUNKNOWN;
  	else
  		chip = ret;
  
  	ret = bq2415x_detect_revision(bq);
  	if (ret < 0)
  		strcpy(revstr, "unknown");
  	else
  		sprintf(revstr, "1.%d", ret);
  
  	bq->model = kasprintf(GFP_KERNEL,
  				"chip %s, revision %s, vender code %.3d",
  				bq2415x_chip_name[chip], revstr,
  				bq2415x_get_vender_code(bq));
  	if (!bq->model) {
  		dev_err(bq->dev, "failed to allocate model name
  ");
  		return -ENOMEM;
  	}

  	bq->charger = power_supply_register(bq->dev, &bq->charger_desc,
  					    &psy_cfg);
  	if (IS_ERR(bq->charger)) {

  		kfree(bq->model);

  		return PTR_ERR(bq->charger);

  	}
  
  	return 0;
  }
  
  static void bq2415x_power_supply_exit(struct bq2415x_device *bq)
  {
  	bq->autotimer = 0;
  	if (bq->automode > 0)
  		bq->automode = 0;
  	cancel_delayed_work_sync(&bq->work);

  	power_supply_unregister(bq->charger);

  	kfree(bq->model);
  }
  
  /**** additional sysfs entries for power supply interface ****/
  
  /* show *_status entries */
  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 = power_supply_get_drvdata(psy);

  	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;

  	return sprintf(buf, "%d
  ", ret);

  }

  /*
   * set timer entry:
   *    auto - enable auto mode
   *    off - disable auto mode
   *    (other values) - reset chip timer
   */

  static ssize_t bq2415x_sysfs_set_timer(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 = power_supply_get_drvdata(psy);

  	int ret = 0;
  
  	if (strncmp(buf, "auto", 4) == 0)
  		bq2415x_set_autotimer(bq, 1);
  	else if (strncmp(buf, "off", 3) == 0)
  		bq2415x_set_autotimer(bq, 0);
  	else
  		ret = bq2415x_exec_command(bq, BQ2415X_TIMER_RESET);
  
  	if (ret < 0)
  		return ret;

  	return count;

  }
  
  /* show timer entry (auto or off) */
  static ssize_t bq2415x_sysfs_show_timer(struct device *dev,

  					struct device_attribute *attr,
  					char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  
  	if (bq->timer_error)
  		return sprintf(buf, "%s
  ", bq->timer_error);
  
  	if (bq->autotimer)
  		return sprintf(buf, "auto
  ");

  	return sprintf(buf, "off
  ");

  }

  /*
   * set mode entry:
   *    auto - if automode is supported, enable it and set mode to reported
   *    none - disable charger and boost mode
   *    host - charging mode for host/hub chargers (current limit 500mA)
   *    dedicated - charging mode for dedicated chargers (unlimited current limit)
   *    boost - disable charger and enable boost mode
   */

  static ssize_t bq2415x_sysfs_set_mode(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 = power_supply_get_drvdata(psy);

  	enum bq2415x_mode mode;
  	int ret = 0;
  
  	if (strncmp(buf, "auto", 4) == 0) {
  		if (bq->automode < 0)

  			return -EINVAL;

  		bq->automode = 1;
  		mode = bq->reported_mode;

  	} else if (strncmp(buf, "off", 3) == 0) {
  		if (bq->automode > 0)
  			bq->automode = 0;
  		mode = BQ2415X_MODE_OFF;

  	} else if (strncmp(buf, "none", 4) == 0) {
  		if (bq->automode > 0)
  			bq->automode = 0;
  		mode = BQ2415X_MODE_NONE;
  	} else if (strncmp(buf, "host", 4) == 0) {
  		if (bq->automode > 0)
  			bq->automode = 0;
  		mode = BQ2415X_MODE_HOST_CHARGER;
  	} else if (strncmp(buf, "dedicated", 9) == 0) {
  		if (bq->automode > 0)
  			bq->automode = 0;
  		mode = BQ2415X_MODE_DEDICATED_CHARGER;
  	} else if (strncmp(buf, "boost", 5) == 0) {
  		if (bq->automode > 0)
  			bq->automode = 0;
  		mode = BQ2415X_MODE_BOOST;
  	} else if (strncmp(buf, "reset", 5) == 0) {
  		bq2415x_reset_chip(bq);
  		bq2415x_set_defaults(bq);
  		if (bq->automode <= 0)
  			return count;
  		bq->automode = 1;
  		mode = bq->reported_mode;

  	} else {

  		return -EINVAL;

  	}

  
  	ret = bq2415x_set_mode(bq, mode);
  	if (ret < 0)
  		return ret;

  	return count;

  }
  
  /* show mode entry (auto, none, host, dedicated or boost) */
  static ssize_t bq2415x_sysfs_show_mode(struct device *dev,

  				       struct device_attribute *attr,
  				       char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  	ssize_t ret = 0;
  
  	if (bq->automode > 0)
  		ret += sprintf(buf+ret, "auto (");
  
  	switch (bq->mode) {

  	case BQ2415X_MODE_OFF:
  		ret += sprintf(buf+ret, "off");
  		break;

  	case BQ2415X_MODE_NONE:
  		ret += sprintf(buf+ret, "none");
  		break;
  	case BQ2415X_MODE_HOST_CHARGER:
  		ret += sprintf(buf+ret, "host");
  		break;
  	case BQ2415X_MODE_DEDICATED_CHARGER:
  		ret += sprintf(buf+ret, "dedicated");
  		break;
  	case BQ2415X_MODE_BOOST:
  		ret += sprintf(buf+ret, "boost");
  		break;
  	}
  
  	if (bq->automode > 0)
  		ret += sprintf(buf+ret, ")");
  
  	ret += sprintf(buf+ret, "
  ");
  	return ret;
  }
  
  /* show reported_mode entry (none, host, dedicated or boost) */
  static ssize_t bq2415x_sysfs_show_reported_mode(struct device *dev,

  						struct device_attribute *attr,
  						char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  
  	if (bq->automode < 0)
  		return -EINVAL;
  
  	switch (bq->reported_mode) {

  	case BQ2415X_MODE_OFF:
  		return sprintf(buf, "off
  ");

  	case BQ2415X_MODE_NONE:
  		return sprintf(buf, "none
  ");
  	case BQ2415X_MODE_HOST_CHARGER:
  		return sprintf(buf, "host
  ");
  	case BQ2415X_MODE_DEDICATED_CHARGER:
  		return sprintf(buf, "dedicated
  ");
  	case BQ2415X_MODE_BOOST:
  		return sprintf(buf, "boost
  ");
  	}
  
  	return -EINVAL;
  }
  
  /* directly set raw value to chip register, format: 'register value' */
  static ssize_t bq2415x_sysfs_set_registers(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 = power_supply_get_drvdata(psy);

  	ssize_t ret = 0;
  	unsigned int reg;
  	unsigned int val;
  
  	if (sscanf(buf, "%x %x", &reg, &val) != 2)
  		return -EINVAL;
  
  	if (reg > 4 || val > 255)
  		return -EINVAL;
  
  	ret = bq2415x_i2c_write(bq, reg, val);
  	if (ret < 0)
  		return ret;

  	return count;

  }
  
  /* print value of chip register, format: 'register=value' */
  static ssize_t bq2415x_sysfs_print_reg(struct bq2415x_device *bq,

  				       u8 reg,
  				       char *buf)

  {
  	int ret = bq2415x_i2c_read(bq, reg);

  	if (ret < 0)
  		return sprintf(buf, "%#.2x=error %d
  ", reg, ret);

  	return sprintf(buf, "%#.2x=%#.2x
  ", reg, ret);

  }
  
  /* show all raw values of chip register, format per line: 'register=value' */
  static ssize_t bq2415x_sysfs_show_registers(struct device *dev,

  					    struct device_attribute *attr,
  					    char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  	ssize_t ret = 0;
  
  	ret += bq2415x_sysfs_print_reg(bq, BQ2415X_REG_STATUS, buf+ret);
  	ret += bq2415x_sysfs_print_reg(bq, BQ2415X_REG_CONTROL, buf+ret);
  	ret += bq2415x_sysfs_print_reg(bq, BQ2415X_REG_VOLTAGE, buf+ret);
  	ret += bq2415x_sysfs_print_reg(bq, BQ2415X_REG_VENDER, buf+ret);
  	ret += bq2415x_sysfs_print_reg(bq, BQ2415X_REG_CURRENT, buf+ret);
  	return ret;
  }
  
  /* set current and voltage limit entries (in mA or mV) */
  static ssize_t bq2415x_sysfs_set_limit(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 = power_supply_get_drvdata(psy);

  	long val;
  	int ret;
  
  	if (kstrtol(buf, 10, &val) < 0)
  		return -EINVAL;
  
  	if (strcmp(attr->attr.name, "current_limit") == 0)
  		ret = bq2415x_set_current_limit(bq, val);
  	else if (strcmp(attr->attr.name, "weak_battery_voltage") == 0)
  		ret = bq2415x_set_weak_battery_voltage(bq, val);
  	else if (strcmp(attr->attr.name, "battery_regulation_voltage") == 0)
  		ret = bq2415x_set_battery_regulation_voltage(bq, val);
  	else if (strcmp(attr->attr.name, "charge_current") == 0)
  		ret = bq2415x_set_charge_current(bq, val);
  	else if (strcmp(attr->attr.name, "termination_current") == 0)
  		ret = bq2415x_set_termination_current(bq, val);
  	else
  		return -EINVAL;
  
  	if (ret < 0)
  		return ret;

  	return count;

  }
  
  /* show current and voltage limit entries (in mA or mV) */
  static ssize_t bq2415x_sysfs_show_limit(struct device *dev,

  					struct device_attribute *attr,
  					char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  	int ret;
  
  	if (strcmp(attr->attr.name, "current_limit") == 0)
  		ret = bq2415x_get_current_limit(bq);
  	else if (strcmp(attr->attr.name, "weak_battery_voltage") == 0)
  		ret = bq2415x_get_weak_battery_voltage(bq);
  	else if (strcmp(attr->attr.name, "battery_regulation_voltage") == 0)
  		ret = bq2415x_get_battery_regulation_voltage(bq);
  	else if (strcmp(attr->attr.name, "charge_current") == 0)
  		ret = bq2415x_get_charge_current(bq);
  	else if (strcmp(attr->attr.name, "termination_current") == 0)
  		ret = bq2415x_get_termination_current(bq);
  	else
  		return -EINVAL;
  
  	if (ret < 0)
  		return ret;

  	return sprintf(buf, "%d
  ", ret);

  }
  
  /* set *_enable entries */
  static ssize_t bq2415x_sysfs_set_enable(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 = power_supply_get_drvdata(psy);

  	enum bq2415x_command command;
  	long val;
  	int ret;
  
  	if (kstrtol(buf, 10, &val) < 0)
  		return -EINVAL;
  
  	if (strcmp(attr->attr.name, "charge_termination_enable") == 0)
  		command = val ? BQ2415X_CHARGE_TERMINATION_ENABLE :
  			BQ2415X_CHARGE_TERMINATION_DISABLE;
  	else if (strcmp(attr->attr.name, "high_impedance_enable") == 0)
  		command = val ? BQ2415X_HIGH_IMPEDANCE_ENABLE :
  			BQ2415X_HIGH_IMPEDANCE_DISABLE;
  	else if (strcmp(attr->attr.name, "otg_pin_enable") == 0)
  		command = val ? BQ2415X_OTG_PIN_ENABLE :
  			BQ2415X_OTG_PIN_DISABLE;
  	else if (strcmp(attr->attr.name, "stat_pin_enable") == 0)
  		command = val ? BQ2415X_STAT_PIN_ENABLE :
  			BQ2415X_STAT_PIN_DISABLE;
  	else
  		return -EINVAL;
  
  	ret = bq2415x_exec_command(bq, command);
  	if (ret < 0)
  		return ret;

  	return count;

  }
  
  /* show *_enable entries */
  static ssize_t bq2415x_sysfs_show_enable(struct device *dev,

  					 struct device_attribute *attr,
  					 char *buf)

  {
  	struct power_supply *psy = dev_get_drvdata(dev);

  	struct bq2415x_device *bq = power_supply_get_drvdata(psy);

  	enum bq2415x_command command;
  	int ret;
  
  	if (strcmp(attr->attr.name, "charge_termination_enable") == 0)
  		command = BQ2415X_CHARGE_TERMINATION_STATUS;
  	else if (strcmp(attr->attr.name, "high_impedance_enable") == 0)
  		command = BQ2415X_HIGH_IMPEDANCE_STATUS;
  	else if (strcmp(attr->attr.name, "otg_pin_enable") == 0)
  		command = BQ2415X_OTG_PIN_STATUS;
  	else if (strcmp(attr->attr.name, "stat_pin_enable") == 0)
  		command = BQ2415X_STAT_PIN_STATUS;
  	else
  		return -EINVAL;
  
  	ret = bq2415x_exec_command(bq, command);
  	if (ret < 0)
  		return ret;

  	return sprintf(buf, "%d
  ", ret);

  }
  
  static DEVICE_ATTR(current_limit, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_limit, bq2415x_sysfs_set_limit);
  static DEVICE_ATTR(weak_battery_voltage, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_limit, bq2415x_sysfs_set_limit);
  static DEVICE_ATTR(battery_regulation_voltage, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_limit, bq2415x_sysfs_set_limit);
  static DEVICE_ATTR(charge_current, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_limit, bq2415x_sysfs_set_limit);
  static DEVICE_ATTR(termination_current, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_limit, bq2415x_sysfs_set_limit);
  
  static DEVICE_ATTR(charge_termination_enable, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_enable, bq2415x_sysfs_set_enable);
  static DEVICE_ATTR(high_impedance_enable, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_enable, bq2415x_sysfs_set_enable);
  static DEVICE_ATTR(otg_pin_enable, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_enable, bq2415x_sysfs_set_enable);
  static DEVICE_ATTR(stat_pin_enable, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_enable, bq2415x_sysfs_set_enable);
  
  static DEVICE_ATTR(reported_mode, S_IRUGO,
  		bq2415x_sysfs_show_reported_mode, NULL);
  static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_mode, bq2415x_sysfs_set_mode);
  static DEVICE_ATTR(timer, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_timer, bq2415x_sysfs_set_timer);
  
  static DEVICE_ATTR(registers, S_IWUSR | S_IRUGO,
  		bq2415x_sysfs_show_registers, bq2415x_sysfs_set_registers);
  
  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[] = {

  	/*
  	 * TODO: some (appropriate) of these attrs should be switched to
  	 * use power supply class props.
  	 */

  	&dev_attr_current_limit.attr,
  	&dev_attr_weak_battery_voltage.attr,
  	&dev_attr_battery_regulation_voltage.attr,
  	&dev_attr_charge_current.attr,
  	&dev_attr_termination_current.attr,
  
  	&dev_attr_charge_termination_enable.attr,
  	&dev_attr_high_impedance_enable.attr,
  	&dev_attr_otg_pin_enable.attr,
  	&dev_attr_stat_pin_enable.attr,
  
  	&dev_attr_reported_mode.attr,
  	&dev_attr_mode.attr,
  	&dev_attr_timer.attr,
  
  	&dev_attr_registers.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);

  }
  
  /* main bq2415x probe function */
  static int bq2415x_probe(struct i2c_client *client,

  			 const struct i2c_device_id *id)

  {
  	int ret;
  	int num;

  	char *name = NULL;

  	struct bq2415x_device *bq;

  	struct device_node *np = client->dev.of_node;
  	struct bq2415x_platform_data *pdata = client->dev.platform_data;

  	const struct acpi_device_id *acpi_id = NULL;

  	struct power_supply *notify_psy = NULL;
  	union power_supply_propval prop;

  	if (!np && !pdata && !ACPI_HANDLE(&client->dev)) {
  		dev_err(&client->dev, "Neither devicetree, nor platform data, nor ACPI support
  ");

  		return -ENODEV;
  	}
  
  	/* Get new ID for the new device */

  	mutex_lock(&bq2415x_id_mutex);

  	num = idr_alloc(&bq2415x_id, client, 0, 0, GFP_KERNEL);

  	mutex_unlock(&bq2415x_id_mutex);

  	if (num < 0)
  		return num;

  	if (id) {
  		name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
  	} else if (ACPI_HANDLE(&client->dev)) {
  		acpi_id =
  			acpi_match_device(client->dev.driver->acpi_match_table,
  					  &client->dev);
  		name = kasprintf(GFP_KERNEL, "%s-%d", acpi_id->id, num);
  	}

  	if (!name) {
  		dev_err(&client->dev, "failed to allocate device name
  ");
  		ret = -ENOMEM;
  		goto error_1;
  	}

  	bq = devm_kzalloc(&client->dev, sizeof(*bq), GFP_KERNEL);

  	if (!bq) {

  		ret = -ENOMEM;
  		goto error_2;
  	}
  
  	i2c_set_clientdata(client, bq);
  
  	bq->id = num;
  	bq->dev = &client->dev;

  	if (id)
  		bq->chip = id->driver_data;
  	else if (ACPI_HANDLE(bq->dev))
  		bq->chip = acpi_id->driver_data;

  	bq->name = name;

  	bq->mode = BQ2415X_MODE_OFF;
  	bq->reported_mode = BQ2415X_MODE_OFF;

  	bq->autotimer = 0;
  	bq->automode = 0;

  	if (np || ACPI_HANDLE(bq->dev)) {
  		ret = device_property_read_u32(bq->dev,
  					       "ti,current-limit",
  					       &bq->init_data.current_limit);

  		if (ret)

  			goto error_2;

  		ret = device_property_read_u32(bq->dev,
  					"ti,weak-battery-voltage",
  					&bq->init_data.weak_battery_voltage);

  		if (ret)

  			goto error_2;

  		ret = device_property_read_u32(bq->dev,
  				"ti,battery-regulation-voltage",

  				&bq->init_data.battery_regulation_voltage);
  		if (ret)

  			goto error_2;

  		ret = device_property_read_u32(bq->dev,
  					       "ti,charge-current",
  					       &bq->init_data.charge_current);

  		if (ret)

  			goto error_2;

  		ret = device_property_read_u32(bq->dev,
  				"ti,termination-current",
  				&bq->init_data.termination_current);

  		if (ret)

  			goto error_2;

  		ret = device_property_read_u32(bq->dev,
  					       "ti,resistor-sense",
  					       &bq->init_data.resistor_sense);

  		if (ret)

  			goto error_2;
  		if (np)
  			bq->notify_node = of_parse_phandle(np,
  						"ti,usb-charger-detection", 0);

  	} else {
  		memcpy(&bq->init_data, pdata, sizeof(bq->init_data));
  	}

  
  	bq2415x_reset_chip(bq);
  
  	ret = bq2415x_power_supply_init(bq);
  	if (ret) {
  		dev_err(bq->dev, "failed to register power supply: %d
  ", ret);

  		goto error_2;

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

  		goto error_3;

  	}
  
  	ret = bq2415x_set_defaults(bq);
  	if (ret) {
  		dev_err(bq->dev, "failed to set default values: %d
  ", ret);

  		goto error_4;

  	}

  	if (bq->notify_node || bq->init_data.notify_device) {

  		bq->nb.notifier_call = bq2415x_notifier_call;
  		ret = power_supply_reg_notifier(&bq->nb);
  		if (ret) {
  			dev_err(bq->dev, "failed to reg notifier: %d
  ", ret);

  			goto error_4;

  		}

  		bq->automode = 1;

  		dev_info(bq->dev, "automode supported, waiting for events
  ");

  	} else {
  		bq->automode = -1;
  		dev_info(bq->dev, "automode not supported
  ");
  	}

  	/* Query for initial reported_mode and set it */
  	if (bq->nb.notifier_call) {
  		if (np) {
  			notify_psy = power_supply_get_by_phandle(np,
  						"ti,usb-charger-detection");
  			if (IS_ERR(notify_psy))
  				notify_psy = NULL;
  		} else if (bq->init_data.notify_device) {
  			notify_psy = power_supply_get_by_name(
  						bq->init_data.notify_device);
  		}
  	}
  	if (notify_psy) {
  		ret = power_supply_get_property(notify_psy,
  					POWER_SUPPLY_PROP_CURRENT_MAX, &prop);
  		power_supply_put(notify_psy);
  
  		if (ret == 0) {
  			bq2415x_update_reported_mode(bq, prop.intval);
  			bq2415x_set_mode(bq, bq->reported_mode);
  		}
  	}

  	INIT_DELAYED_WORK(&bq->work, bq2415x_timer_work);
  	bq2415x_set_autotimer(bq, 1);
  
  	dev_info(bq->dev, "driver registered
  ");
  	return 0;

  error_4:

  	bq2415x_sysfs_exit(bq);

  error_3:

  	bq2415x_power_supply_exit(bq);

  error_2:

  	if (bq)

  		of_node_put(bq->notify_node);

  	kfree(name);
  error_1:
  	mutex_lock(&bq2415x_id_mutex);
  	idr_remove(&bq2415x_id, num);
  	mutex_unlock(&bq2415x_id_mutex);
  
  	return ret;
  }
  
  /* main bq2415x remove function */
  
  static int bq2415x_remove(struct i2c_client *client)
  {
  	struct bq2415x_device *bq = i2c_get_clientdata(client);

  	if (bq->nb.notifier_call)

  		power_supply_unreg_notifier(&bq->nb);

  	of_node_put(bq->notify_node);

  	bq2415x_sysfs_exit(bq);
  	bq2415x_power_supply_exit(bq);
  
  	bq2415x_reset_chip(bq);
  
  	mutex_lock(&bq2415x_id_mutex);
  	idr_remove(&bq2415x_id, bq->id);
  	mutex_unlock(&bq2415x_id_mutex);
  
  	dev_info(bq->dev, "driver unregistered
  ");
  
  	kfree(bq->name);

  
  	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 },

  	{ "bq24157s", BQ24157S },

  	{ "bq24158", BQ24158 },
  	{},
  };
  MODULE_DEVICE_TABLE(i2c, bq2415x_i2c_id_table);

  #ifdef CONFIG_ACPI

  static const struct acpi_device_id bq2415x_i2c_acpi_match[] = {
  	{ "BQ2415X", BQUNKNOWN },
  	{ "BQ241500", BQ24150 },
  	{ "BQA24150", BQ24150A },
  	{ "BQ241510", BQ24151 },
  	{ "BQA24151", BQ24151A },
  	{ "BQ241520", BQ24152 },
  	{ "BQ241530", BQ24153 },
  	{ "BQA24153", BQ24153A },
  	{ "BQ241550", BQ24155 },
  	{ "BQ241560", BQ24156 },
  	{ "BQA24156", BQ24156A },
  	{ "BQS24157", BQ24157S },
  	{ "BQ241580", BQ24158 },
  	{},
  };
  MODULE_DEVICE_TABLE(acpi, bq2415x_i2c_acpi_match);

  #endif

  #ifdef CONFIG_OF
  static const struct of_device_id bq2415x_of_match_table[] = {
  	{ .compatible = "ti,bq24150" },
  	{ .compatible = "ti,bq24150a" },
  	{ .compatible = "ti,bq24151" },
  	{ .compatible = "ti,bq24151a" },
  	{ .compatible = "ti,bq24152" },
  	{ .compatible = "ti,bq24153" },
  	{ .compatible = "ti,bq24153a" },
  	{ .compatible = "ti,bq24155" },
  	{ .compatible = "ti,bq24156" },
  	{ .compatible = "ti,bq24156a" },
  	{ .compatible = "ti,bq24157s" },
  	{ .compatible = "ti,bq24158" },
  	{},
  };
  MODULE_DEVICE_TABLE(of, bq2415x_of_match_table);
  #endif

  static struct i2c_driver bq2415x_driver = {
  	.driver = {
  		.name = "bq2415x-charger",

  		.of_match_table = of_match_ptr(bq2415x_of_match_table),

  		.acpi_match_table = ACPI_PTR(bq2415x_i2c_acpi_match),

  	},
  	.probe = bq2415x_probe,
  	.remove = bq2415x_remove,
  	.id_table = bq2415x_i2c_id_table,
  };

  module_i2c_driver(bq2415x_driver);

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