/*
   * BQ27x00 battery driver
   *
   * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
   * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>

   * Copyright (C) 2010-2011 Lars-Peter Clausen <lars@metafoo.de>

   * Copyright (C) 2011 Pali Rohár <pali.rohar@gmail.com>

   *
   * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
   *
   * This package 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.
   *
   * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
   * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
   *
   */

  
  /*
   * Datasheets:
   * http://focus.ti.com/docs/prod/folders/print/bq27000.html
   * http://focus.ti.com/docs/prod/folders/print/bq27500.html
   */

  #include <linux/module.h>
  #include <linux/param.h>
  #include <linux/jiffies.h>
  #include <linux/workqueue.h>
  #include <linux/delay.h>
  #include <linux/platform_device.h>
  #include <linux/power_supply.h>
  #include <linux/idr.h>

  #include <linux/i2c.h>

  #include <linux/slab.h>

  #include <asm/unaligned.h>

  #include <linux/power/bq27x00_battery.h>

  #define DRIVER_VERSION			"1.2.0"

  
  #define BQ27x00_REG_TEMP		0x06
  #define BQ27x00_REG_VOLT		0x08

  #define BQ27x00_REG_AI			0x14
  #define BQ27x00_REG_FLAGS		0x0A

  #define BQ27x00_REG_TTE			0x16
  #define BQ27x00_REG_TTF			0x18
  #define BQ27x00_REG_TTECP		0x26

  #define BQ27x00_REG_NAC			0x0C /* Nominal available capaciy */
  #define BQ27x00_REG_LMD			0x12 /* Last measured discharge */
  #define BQ27x00_REG_CYCT		0x2A /* Cycle count total */
  #define BQ27x00_REG_AE			0x22 /* Available enery */

  #define BQ27000_REG_RSOC		0x0B /* Relative State-of-Charge */

  #define BQ27000_REG_ILMD		0x76 /* Initial last measured discharge */

  #define BQ27000_FLAG_EDVF		BIT(0) /* Final End-of-Discharge-Voltage flag */
  #define BQ27000_FLAG_EDV1		BIT(1) /* First End-of-Discharge-Voltage flag */

  #define BQ27000_FLAG_CI			BIT(4) /* Capacity Inaccurate flag */

  #define BQ27000_FLAG_FC			BIT(5)

  #define BQ27000_FLAG_CHGS		BIT(7) /* Charge state flag */

  #define BQ27500_REG_SOC			0x2C

  #define BQ27500_REG_DCAP		0x3C /* Design capacity */

  #define BQ27500_FLAG_DSG		BIT(0) /* Discharging */

  #define BQ27500_FLAG_SOCF		BIT(1) /* State-of-Charge threshold final */
  #define BQ27500_FLAG_SOC1		BIT(2) /* State-of-Charge threshold 1 */

  #define BQ27500_FLAG_CHG		BIT(8) /* Charging */
  #define BQ27500_FLAG_FC			BIT(9) /* Fully charged */

  #define BQ27000_RS			20 /* Resistor sense */

  struct bq27x00_device_info;
  struct bq27x00_access_methods {

  	int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);

  };

  enum bq27x00_chip { BQ27000, BQ27500 };

  struct bq27x00_reg_cache {
  	int temperature;
  	int time_to_empty;
  	int time_to_empty_avg;
  	int time_to_full;

  	int charge_full;

  	int cycle_count;

  	int capacity;

  	int energy;

  	int flags;

  };

  struct bq27x00_device_info {
  	struct device 		*dev;
  	int			id;

  	enum bq27x00_chip	chip;

  	struct bq27x00_reg_cache cache;

  	int charge_design_full;

  	unsigned long last_update;

  	struct delayed_work work;

  	struct power_supply	bat;
  
  	struct bq27x00_access_methods bus;

  
  	struct mutex lock;

  };
  
  static enum power_supply_property bq27x00_battery_props[] = {

  	POWER_SUPPLY_PROP_STATUS,

  	POWER_SUPPLY_PROP_PRESENT,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_CURRENT_NOW,
  	POWER_SUPPLY_PROP_CAPACITY,

  	POWER_SUPPLY_PROP_CAPACITY_LEVEL,

  	POWER_SUPPLY_PROP_TEMP,

  	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
  	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
  	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,

  	POWER_SUPPLY_PROP_TECHNOLOGY,

  	POWER_SUPPLY_PROP_CHARGE_FULL,
  	POWER_SUPPLY_PROP_CHARGE_NOW,
  	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,

  	POWER_SUPPLY_PROP_CYCLE_COUNT,

  	POWER_SUPPLY_PROP_ENERGY_NOW,

  };

  static unsigned int poll_interval = 360;
  module_param(poll_interval, uint, 0644);
  MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
  				"0 disables polling");

  /*
   * Common code for BQ27x00 devices
   */

  static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,

  		bool single)

  {

  	return di->bus.read(di, reg, single);

  }
  
  /*

   * Return the battery Relative State-of-Charge

   * Or < 0 if something fails.
   */

  static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)

  {

  	int rsoc;

  	if (di->chip == BQ27500)

  		rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);

  	else

  		rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
  
  	if (rsoc < 0)

  		dev_dbg(di->dev, "error reading relative State-of-Charge
  ");

  
  	return rsoc;

  }
  
  /*

   * Return a battery charge value in µAh
   * Or < 0 if something fails.
   */
  static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
  {
  	int charge;
  
  	charge = bq27x00_read(di, reg, false);
  	if (charge < 0) {

  		dev_dbg(di->dev, "error reading charge register %02x: %d
  ",
  			reg, charge);

  		return charge;
  	}
  
  	if (di->chip == BQ27500)
  		charge *= 1000;
  	else
  		charge = charge * 3570 / BQ27000_RS;
  
  	return charge;
  }
  
  /*
   * Return the battery Nominal available capaciy in µAh
   * Or < 0 if something fails.
   */
  static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
  {
  	return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
  }
  
  /*
   * Return the battery Last measured discharge in µAh
   * Or < 0 if something fails.
   */
  static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
  {
  	return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
  }
  
  /*
   * Return the battery Initial last measured discharge in µAh
   * Or < 0 if something fails.
   */
  static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
  {
  	int ilmd;
  
  	if (di->chip == BQ27500)
  		ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
  	else
  		ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
  
  	if (ilmd < 0) {

  		dev_dbg(di->dev, "error reading initial last measured discharge
  ");

  		return ilmd;
  	}
  
  	if (di->chip == BQ27500)
  		ilmd *= 1000;
  	else
  		ilmd = ilmd * 256 * 3570 / BQ27000_RS;
  
  	return ilmd;
  }
  
  /*

   * Return the battery Available energy in µWh
   * Or < 0 if something fails.
   */
  static int bq27x00_battery_read_energy(struct bq27x00_device_info *di)
  {
  	int ae;
  
  	ae = bq27x00_read(di, BQ27x00_REG_AE, false);
  	if (ae < 0) {

  		dev_dbg(di->dev, "error reading available energy
  ");

  		return ae;
  	}
  
  	if (di->chip == BQ27500)
  		ae *= 1000;
  	else
  		ae = ae * 29200 / BQ27000_RS;
  
  	return ae;
  }
  
  /*

   * Return the battery temperature in tenths of degree Celsius
   * Or < 0 if something fails.
   */
  static int bq27x00_battery_read_temperature(struct bq27x00_device_info *di)
  {
  	int temp;
  
  	temp = bq27x00_read(di, BQ27x00_REG_TEMP, false);
  	if (temp < 0) {
  		dev_err(di->dev, "error reading temperature
  ");
  		return temp;
  	}
  
  	if (di->chip == BQ27500)
  		temp -= 2731;
  	else
  		temp = ((temp * 5) - 5463) / 2;
  
  	return temp;
  }
  
  /*

   * Return the battery Cycle count total
   * Or < 0 if something fails.
   */
  static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
  {
  	int cyct;
  
  	cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
  	if (cyct < 0)
  		dev_err(di->dev, "error reading cycle count total
  ");
  
  	return cyct;
  }
  
  /*

   * Read a time register.
   * Return < 0 if something fails.

   */

  static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)

  {

  	int tval;

  	tval = bq27x00_read(di, reg, false);
  	if (tval < 0) {

  		dev_dbg(di->dev, "error reading time register %02x: %d
  ",
  			reg, tval);

  		return tval;

  	}

  	if (tval == 65535)
  		return -ENODATA;
  
  	return tval * 60;
  }
  
  static void bq27x00_update(struct bq27x00_device_info *di)
  {
  	struct bq27x00_reg_cache cache = {0, };
  	bool is_bq27500 = di->chip == BQ27500;
  
  	cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
  	if (cache.flags >= 0) {

  		if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {

  			dev_info(di->dev, "battery is not calibrated! ignoring capacity values
  ");

  			cache.capacity = -ENODATA;

  			cache.energy = -ENODATA;

  			cache.time_to_empty = -ENODATA;
  			cache.time_to_empty_avg = -ENODATA;
  			cache.time_to_full = -ENODATA;
  			cache.charge_full = -ENODATA;
  		} else {
  			cache.capacity = bq27x00_battery_read_rsoc(di);

  			cache.energy = bq27x00_battery_read_energy(di);

  			cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
  			cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
  			cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
  			cache.charge_full = bq27x00_battery_read_lmd(di);
  		}

  		cache.temperature = bq27x00_battery_read_temperature(di);

  		cache.cycle_count = bq27x00_battery_read_cyct(di);

  		/* We only have to read charge design full once */
  		if (di->charge_design_full <= 0)
  			di->charge_design_full = bq27x00_battery_read_ilmd(di);

  	}

  	if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {

  		di->cache = cache;
  		power_supply_changed(&di->bat);
  	}
  
  	di->last_update = jiffies;
  }

  static void bq27x00_battery_poll(struct work_struct *work)
  {
  	struct bq27x00_device_info *di =
  		container_of(work, struct bq27x00_device_info, work.work);
  
  	bq27x00_update(di);
  
  	if (poll_interval > 0) {
  		/* The timer does not have to be accurate. */
  		set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
  		schedule_delayed_work(&di->work, poll_interval * HZ);
  	}
  }

  /*

   * Return the battery average current in µA

   * Note that current can be negative signed as well
   * Or 0 if something fails.
   */

  static int bq27x00_battery_current(struct bq27x00_device_info *di,
  	union power_supply_propval *val)

  {

  	int curr;

  	int flags;

  	curr = bq27x00_read(di, BQ27x00_REG_AI, false);

  	if (curr < 0) {
  		dev_err(di->dev, "error reading current
  ");

  		return curr;

  	}

  
  	if (di->chip == BQ27500) {
  		/* bq27500 returns signed value */

  		val->intval = (int)((s16)curr) * 1000;

  	} else {

  		flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
  		if (flags & BQ27000_FLAG_CHGS) {

  			dev_dbg(di->dev, "negative current!
  ");

  			curr = -curr;

  		}

  		val->intval = curr * 3570 / BQ27000_RS;

  	}

  	return 0;

  }

  static int bq27x00_battery_status(struct bq27x00_device_info *di,

  	union power_supply_propval *val)

  {

  	int status;

  
  	if (di->chip == BQ27500) {

  		if (di->cache.flags & BQ27500_FLAG_FC)

  			status = POWER_SUPPLY_STATUS_FULL;

  		else if (di->cache.flags & BQ27500_FLAG_DSG)

  			status = POWER_SUPPLY_STATUS_DISCHARGING;

  		else if (di->cache.flags & BQ27500_FLAG_CHG)

  			status = POWER_SUPPLY_STATUS_CHARGING;

  		else if (power_supply_am_i_supplied(&di->bat))
  			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
  		else
  			status = POWER_SUPPLY_STATUS_UNKNOWN;

  	} else {

  		if (di->cache.flags & BQ27000_FLAG_FC)
  			status = POWER_SUPPLY_STATUS_FULL;
  		else if (di->cache.flags & BQ27000_FLAG_CHGS)

  			status = POWER_SUPPLY_STATUS_CHARGING;

  		else if (power_supply_am_i_supplied(&di->bat))
  			status = POWER_SUPPLY_STATUS_NOT_CHARGING;

  		else
  			status = POWER_SUPPLY_STATUS_DISCHARGING;
  	}
  
  	val->intval = status;

  	return 0;
  }

  static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
  	union power_supply_propval *val)
  {
  	int level;
  
  	if (di->chip == BQ27500) {
  		if (di->cache.flags & BQ27500_FLAG_FC)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
  		else if (di->cache.flags & BQ27500_FLAG_SOC1)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
  		else if (di->cache.flags & BQ27500_FLAG_SOCF)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
  		else
  			level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
  	} else {
  		if (di->cache.flags & BQ27000_FLAG_FC)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
  		else if (di->cache.flags & BQ27000_FLAG_EDV1)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
  		else if (di->cache.flags & BQ27000_FLAG_EDVF)
  			level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
  		else
  			level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
  	}
  
  	val->intval = level;
  
  	return 0;
  }

  /*

   * Return the battery Voltage in milivolts
   * Or < 0 if something fails.

   */

  static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
  	union power_supply_propval *val)

  {

  	int volt;

  	volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);

  	if (volt < 0) {
  		dev_err(di->dev, "error reading voltage
  ");

  		return volt;

  	}

  	val->intval = volt * 1000;
  
  	return 0;
  }
  
  static int bq27x00_simple_value(int value,
  	union power_supply_propval *val)
  {
  	if (value < 0)
  		return value;
  
  	val->intval = value;

  	return 0;
  }

  #define to_bq27x00_device_info(x) container_of((x), \
  				struct bq27x00_device_info, bat);
  
  static int bq27x00_battery_get_property(struct power_supply *psy,
  					enum power_supply_property psp,
  					union power_supply_propval *val)
  {

  	int ret = 0;

  	struct bq27x00_device_info *di = to_bq27x00_device_info(psy);

  	mutex_lock(&di->lock);
  	if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
  		cancel_delayed_work_sync(&di->work);
  		bq27x00_battery_poll(&di->work.work);
  	}
  	mutex_unlock(&di->lock);

  
  	if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)

  		return -ENODEV;

  
  	switch (psp) {

  	case POWER_SUPPLY_PROP_STATUS:
  		ret = bq27x00_battery_status(di, val);
  		break;

  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:

  		ret = bq27x00_battery_voltage(di, val);

  		break;

  	case POWER_SUPPLY_PROP_PRESENT:

  		val->intval = di->cache.flags < 0 ? 0 : 1;

  		break;
  	case POWER_SUPPLY_PROP_CURRENT_NOW:

  		ret = bq27x00_battery_current(di, val);

  		break;
  	case POWER_SUPPLY_PROP_CAPACITY:

  		ret = bq27x00_simple_value(di->cache.capacity, val);

  		break;

  	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
  		ret = bq27x00_battery_capacity_level(di, val);
  		break;

  	case POWER_SUPPLY_PROP_TEMP:

  		ret = bq27x00_simple_value(di->cache.temperature, val);

  		break;

  	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:

  		ret = bq27x00_simple_value(di->cache.time_to_empty, val);

  		break;
  	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:

  		ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);

  		break;
  	case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:

  		ret = bq27x00_simple_value(di->cache.time_to_full, val);

  		break;

  	case POWER_SUPPLY_PROP_TECHNOLOGY:
  		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
  		break;

  	case POWER_SUPPLY_PROP_CHARGE_NOW:
  		ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
  		break;
  	case POWER_SUPPLY_PROP_CHARGE_FULL:
  		ret = bq27x00_simple_value(di->cache.charge_full, val);
  		break;
  	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
  		ret = bq27x00_simple_value(di->charge_design_full, val);
  		break;

  	case POWER_SUPPLY_PROP_CYCLE_COUNT:
  		ret = bq27x00_simple_value(di->cache.cycle_count, val);

  		break;
  	case POWER_SUPPLY_PROP_ENERGY_NOW:

  		ret = bq27x00_simple_value(di->cache.energy, val);

  		break;

  	default:
  		return -EINVAL;
  	}

  	return ret;

  }

  static void bq27x00_external_power_changed(struct power_supply *psy)
  {
  	struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
  
  	cancel_delayed_work_sync(&di->work);
  	schedule_delayed_work(&di->work, 0);
  }

  static int bq27x00_powersupply_init(struct bq27x00_device_info *di)

  {

  	int ret;

  	di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
  	di->bat.properties = bq27x00_battery_props;
  	di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
  	di->bat.get_property = bq27x00_battery_get_property;

  	di->bat.external_power_changed = bq27x00_external_power_changed;
  
  	INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
  	mutex_init(&di->lock);

  
  	ret = power_supply_register(di->dev, &di->bat);
  	if (ret) {
  		dev_err(di->dev, "failed to register battery: %d
  ", ret);
  		return ret;
  	}
  
  	dev_info(di->dev, "support ver. %s enabled
  ", DRIVER_VERSION);

  	bq27x00_update(di);

  	return 0;

  }

  static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
  {

  	/*
  	 * power_supply_unregister call bq27x00_battery_get_property which
  	 * call bq27x00_battery_poll.
  	 * Make sure that bq27x00_battery_poll will not call
  	 * schedule_delayed_work again after unregister (which cause OOPS).
  	 */
  	poll_interval = 0;

  	cancel_delayed_work_sync(&di->work);
  
  	power_supply_unregister(&di->bat);
  
  	mutex_destroy(&di->lock);
  }

  
  /* i2c specific code */
  #ifdef CONFIG_BATTERY_BQ27X00_I2C
  
  /* If the system has several batteries we need a different name for each
   * of them...

   */

  static DEFINE_IDR(battery_id);
  static DEFINE_MUTEX(battery_mutex);

  static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)

  {

  	struct i2c_client *client = to_i2c_client(di->dev);

  	struct i2c_msg msg[2];

  	unsigned char data[2];

  	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 = data;

  	if (single)

  		msg[1].len = 1;

  	else

  		msg[1].len = 2;

  	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));

  	if (ret < 0)
  		return ret;
  
  	if (!single)
  		ret = get_unaligned_le16(data);
  	else
  		ret = data[0];

  	return ret;

  }

  static int bq27x00_battery_probe(struct i2c_client *client,

  				 const struct i2c_device_id *id)
  {
  	char *name;
  	struct bq27x00_device_info *di;

  	int num;
  	int retval = 0;
  
  	/* Get new ID for the new battery device */
  	retval = idr_pre_get(&battery_id, GFP_KERNEL);
  	if (retval == 0)
  		return -ENOMEM;
  	mutex_lock(&battery_mutex);
  	retval = idr_get_new(&battery_id, client, &num);
  	mutex_unlock(&battery_mutex);
  	if (retval < 0)
  		return retval;

  	name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);

  	if (!name) {
  		dev_err(&client->dev, "failed to allocate device name
  ");
  		retval = -ENOMEM;
  		goto batt_failed_1;
  	}
  
  	di = kzalloc(sizeof(*di), GFP_KERNEL);
  	if (!di) {
  		dev_err(&client->dev, "failed to allocate device info data
  ");
  		retval = -ENOMEM;
  		goto batt_failed_2;
  	}

  	di->id = num;

  	di->dev = &client->dev;

  	di->chip = id->driver_data;

  	di->bat.name = name;
  	di->bus.read = &bq27x00_read_i2c;

  	if (bq27x00_powersupply_init(di))

  		goto batt_failed_3;

  
  	i2c_set_clientdata(client, di);

  
  	return 0;

  batt_failed_3:
  	kfree(di);
  batt_failed_2:
  	kfree(name);
  batt_failed_1:
  	mutex_lock(&battery_mutex);
  	idr_remove(&battery_id, num);
  	mutex_unlock(&battery_mutex);
  
  	return retval;
  }

  static int bq27x00_battery_remove(struct i2c_client *client)

  {
  	struct bq27x00_device_info *di = i2c_get_clientdata(client);

  	bq27x00_powersupply_unregister(di);

  
  	kfree(di->bat.name);
  
  	mutex_lock(&battery_mutex);
  	idr_remove(&battery_id, di->id);
  	mutex_unlock(&battery_mutex);
  
  	kfree(di);
  
  	return 0;
  }

  static const struct i2c_device_id bq27x00_id[] = {
  	{ "bq27200", BQ27000 },	/* bq27200 is same as bq27000, but with i2c */
  	{ "bq27500", BQ27500 },

  	{},
  };

  MODULE_DEVICE_TABLE(i2c, bq27x00_id);

  static struct i2c_driver bq27x00_battery_driver = {

  	.driver = {

  		.name = "bq27x00-battery",

  	},

  	.probe = bq27x00_battery_probe,
  	.remove = bq27x00_battery_remove,
  	.id_table = bq27x00_id,

  };

  static inline int bq27x00_battery_i2c_init(void)
  {
  	int ret = i2c_add_driver(&bq27x00_battery_driver);
  	if (ret)
  		printk(KERN_ERR "Unable to register BQ27x00 i2c driver
  ");
  
  	return ret;
  }
  
  static inline void bq27x00_battery_i2c_exit(void)
  {
  	i2c_del_driver(&bq27x00_battery_driver);
  }
  
  #else
  
  static inline int bq27x00_battery_i2c_init(void) { return 0; }
  static inline void bq27x00_battery_i2c_exit(void) {};
  
  #endif
  
  /* platform specific code */
  #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
  
  static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,

  			bool single)

  {
  	struct device *dev = di->dev;
  	struct bq27000_platform_data *pdata = dev->platform_data;
  	unsigned int timeout = 3;
  	int upper, lower;
  	int temp;
  
  	if (!single) {
  		/* Make sure the value has not changed in between reading the
  		 * lower and the upper part */
  		upper = pdata->read(dev, reg + 1);
  		do {
  			temp = upper;
  			if (upper < 0)
  				return upper;
  
  			lower = pdata->read(dev, reg);
  			if (lower < 0)
  				return lower;
  
  			upper = pdata->read(dev, reg + 1);
  		} while (temp != upper && --timeout);
  
  		if (timeout == 0)
  			return -EIO;

  		return (upper << 8) | lower;

  	}

  
  	return pdata->read(dev, reg);

  }
  
  static int __devinit bq27000_battery_probe(struct platform_device *pdev)
  {
  	struct bq27x00_device_info *di;
  	struct bq27000_platform_data *pdata = pdev->dev.platform_data;
  	int ret;
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "no platform_data supplied
  ");
  		return -EINVAL;
  	}
  
  	if (!pdata->read) {
  		dev_err(&pdev->dev, "no hdq read callback supplied
  ");
  		return -EINVAL;
  	}
  
  	di = kzalloc(sizeof(*di), GFP_KERNEL);
  	if (!di) {
  		dev_err(&pdev->dev, "failed to allocate device info data
  ");
  		return -ENOMEM;
  	}
  
  	platform_set_drvdata(pdev, di);
  
  	di->dev = &pdev->dev;
  	di->chip = BQ27000;
  
  	di->bat.name = pdata->name ?: dev_name(&pdev->dev);
  	di->bus.read = &bq27000_read_platform;
  
  	ret = bq27x00_powersupply_init(di);
  	if (ret)
  		goto err_free;
  
  	return 0;
  
  err_free:
  	platform_set_drvdata(pdev, NULL);
  	kfree(di);
  
  	return ret;
  }
  
  static int __devexit bq27000_battery_remove(struct platform_device *pdev)
  {
  	struct bq27x00_device_info *di = platform_get_drvdata(pdev);

  	bq27x00_powersupply_unregister(di);

  	platform_set_drvdata(pdev, NULL);
  	kfree(di);
  
  	return 0;
  }
  
  static struct platform_driver bq27000_battery_driver = {
  	.probe	= bq27000_battery_probe,
  	.remove = __devexit_p(bq27000_battery_remove),
  	.driver = {
  		.name = "bq27000-battery",
  		.owner = THIS_MODULE,
  	},
  };
  
  static inline int bq27x00_battery_platform_init(void)
  {
  	int ret = platform_driver_register(&bq27000_battery_driver);
  	if (ret)
  		printk(KERN_ERR "Unable to register BQ27000 platform driver
  ");
  
  	return ret;
  }
  
  static inline void bq27x00_battery_platform_exit(void)
  {
  	platform_driver_unregister(&bq27000_battery_driver);
  }
  
  #else
  
  static inline int bq27x00_battery_platform_init(void) { return 0; }
  static inline void bq27x00_battery_platform_exit(void) {};
  
  #endif
  
  /*
   * Module stuff
   */

  static int __init bq27x00_battery_init(void)
  {
  	int ret;

  	ret = bq27x00_battery_i2c_init();
  	if (ret)
  		return ret;
  
  	ret = bq27x00_battery_platform_init();

  	if (ret)

  		bq27x00_battery_i2c_exit();

  
  	return ret;
  }
  module_init(bq27x00_battery_init);
  
  static void __exit bq27x00_battery_exit(void)
  {

  	bq27x00_battery_platform_exit();
  	bq27x00_battery_i2c_exit();

  }
  module_exit(bq27x00_battery_exit);
  
  MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
  MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
  MODULE_LICENSE("GPL");