/*
 * bq2419x-charger.c -- BQ24190/BQ24192/BQ24192i/BQ24193 Charger driver
 *
 * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 * Author: Syed Rafiuddin <srafiuddin@nvidia.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 version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
 * whether express or implied; 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., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307, USA
 */
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kthread.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/power/bq2419x-charger.h>
#include <linux/regmap.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/alarmtimer.h>
#include <generated/mach-types.h>

enum bq2419x_version {
	BQ24190_IC = 0,
	BQ24192_IC,
	BQ24193_IC,
	BQ24192i_IC,
};

/* input current limit */
static const unsigned int iinlim[] = {
	100, 150, 500, 900, 1200, 1500, 2000, 3000,
};

/* Kthread scheduling parameters */
struct sched_param bq2419x_param = {
	.sched_priority = MAX_RT_PRIO - 1,
};

static const struct regmap_config bq2419x_regmap_config = {
	.reg_bits		= 8,
	.val_bits		= 8,
	.max_register		= BQ2419X_MAX_REGS,
};

struct bq2419x_chip {
	struct device			*dev;
	struct regmap			*regmap;
	int				irq;
	int				gpio_otg_iusb;
	int				wdt_refresh_timeout;
	int				wdt_time_sec;

	struct mutex			mutex;
	int				in_current_limit;
	int				status;
	int				rtc_alarm_time;
	void				(*update_status)(int, int);
	int				(*soc_check)(void);
	int				(*vcell_check)(void);
	s32				(*current_check)(void);
	struct regulator_dev		*chg_rdev;
	struct regulator_desc		chg_reg_desc;
	struct regulator_init_data	chg_reg_init_data;

	struct regulator_dev		*vbus_rdev;
	struct regulator_desc		vbus_reg_desc;
	struct regulator_init_data	vbus_reg_init_data;

	struct kthread_worker		bq_kworker;
	struct task_struct		*bq_kworker_task;
	struct kthread_work		bq_wdt_work;
	struct rtc_device		*rtc;
	int				stop_thread;
	int				suspended;
	int				chg_restart_timeout;
	int				chg_restart_time;
	int				chg_complete_soc;
	int				chg_enable;
	int				chip_version;
};

#define FULL_CHARGE_SOC			100
#define MAX_CHARING_VOLTAGE		4202
#define RECHARING_VOLTAGE		4140
#define CHARING_COMPLETE_CURRENT	-256

static int chg_complete_check;

static int current_to_reg(const unsigned int *tbl,
			size_t size, unsigned int val)
{
	size_t i;

	for (i = 0; i < size; i++)
		if (val < tbl[i])
			break;
	return i > 0 ? i - 1 : -EINVAL;
}

static int bq2419x_charger_disable(struct bq2419x_chip *bq2419x)
{
	int ret;

	ret = regmap_update_bits(bq2419x->regmap, BQ2419X_PWR_ON_REG,
			 BQ2419X_ENABLE_CHARGE_MASK,
			 BQ2419X_DISABLE_CHARGE);
	if (ret < 0)
		dev_err(bq2419x->dev, "register update failed, err %d\n", ret);
	return ret;
}

static int bq2419x_charger_enable(struct bq2419x_chip *bq2419x)
{
	int ret;

	if (bq2419x->chg_enable) {
		/* charging enabled reset flag and timeout*/
		chg_complete_check = 0;
		bq2419x->chg_restart_timeout = 0;

		ret = regmap_update_bits(bq2419x->regmap, BQ2419X_PWR_ON_REG,
			 BQ2419X_ENABLE_CHARGE_MASK, BQ2419X_ENABLE_CHARGE);
	} else {
		ret = regmap_update_bits(bq2419x->regmap, BQ2419X_PWR_ON_REG,
				 BQ2419X_ENABLE_CHARGE_MASK,
				 BQ2419X_DISABLE_CHARGE);
	}
	if (ret < 0)
		dev_err(bq2419x->dev, "register update failed, err %d\n", ret);
	return ret;
}

static int bq2419x_vbus_regulator_enable_time(struct regulator_dev *rdev)
{
	return 8000;
}

static int bq2419x_vbus_enable(struct regulator_dev *rdev)
{
	struct bq2419x_chip *bq2419x = rdev_get_drvdata(rdev);
	int ret;

	dev_info(bq2419x->dev, "VBUS enabled, charging disabled\n");

	ret = regmap_update_bits(bq2419x->regmap, BQ2419X_PWR_ON_REG,
			BQ2419X_ENABLE_CHARGE_MASK, BQ2419X_ENABLE_VBUS);
	if (ret < 0)
		dev_err(bq2419x->dev, "PWR_ON_REG update failed %d", ret);

	return ret;
}

static int bq2419x_vbus_disable(struct regulator_dev *rdev)
{
	struct bq2419x_chip *bq2419x = rdev_get_drvdata(rdev);
	int ret;

	dev_info(bq2419x->dev, "VBUS disabled, charging enabled\n");
	ret = bq2419x_charger_enable(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "Charger enable failed %d", ret);
		return ret;
	}

	return ret;
}

static int bq2419x_vbus_is_enabled(struct regulator_dev *rdev)
{
	struct bq2419x_chip *bq2419x = rdev_get_drvdata(rdev);
	int ret;
	unsigned int data;

	ret = regmap_read(bq2419x->regmap, BQ2419X_PWR_ON_REG, &data);
	if (ret < 0) {
		dev_err(bq2419x->dev, "PWR_ON_REG read failed %d", ret);
		return ret;
	}
	return (data & BQ2419X_ENABLE_CHARGE_MASK) == BQ2419X_ENABLE_VBUS;
}

static struct regulator_ops bq2419x_vbus_ops = {
	.enable		= bq2419x_vbus_enable,
	.disable	= bq2419x_vbus_disable,
	.is_enabled	= bq2419x_vbus_is_enabled,
	.enable_time	= bq2419x_vbus_regulator_enable_time,
};

static int bq2419x_init(struct bq2419x_chip *bq2419x)
{
	int val = 0;
	int ret = 0;
	int floor = 0;

	/* Configure input voltage to 4.52 in case of NV charger */
	if (machine_is_roth() && (bq2419x->in_current_limit == 2000))
		val |= BQ2419x_NVCHARGER_INPUT_VOL_SEL;
	else
		val |= BQ2419x_DEFAULT_INPUT_VOL_SEL;

	/* Clear EN_HIZ */
	ret = regmap_update_bits(bq2419x->regmap, BQ2419X_INPUT_SRC_REG,
			BQ2419X_EN_HIZ | BQ2419x_INPUT_VOLTAGE_MASK, val);
	if (ret < 0) {
		dev_err(bq2419x->dev, "INPUT_SRC_REG update failed %d\n", ret);
		return ret;
	}

	/* Set input current limit to 2A in case of DCP */
	if ((machine_is_tegratab() || machine_is_tegranote7c()) &&
			(bq2419x->in_current_limit >= 1800))
		bq2419x->in_current_limit = 2000;

	dev_info(bq2419x->dev,
		"bq2419x_init: bq2419x->in_current_limit %d\n",
		bq2419x->in_current_limit);

	/* Configure input current limit */
	val = current_to_reg(iinlim, ARRAY_SIZE(iinlim),
				bq2419x->in_current_limit);

	/* Start from 100mA and then step to val */
	floor = current_to_reg(iinlim, ARRAY_SIZE(iinlim), 100);
	if (val < 0 || floor < 0)
		return 0;

	for (; floor <= val; floor++) {
		udelay(BQ2419x_CHARGING_CURRENT_STEP_DELAY_US);
		ret = regmap_update_bits(bq2419x->regmap, BQ2419X_INPUT_SRC_REG,
				BQ2419x_CONFIG_MASK, floor);
		if (ret < 0)
			dev_err(bq2419x->dev,
				"INPUT_SRC_REG update failed: %d\n", ret);
	}
	return ret;
}

static int bq2419x_charger_init(struct bq2419x_chip *bq2419x)
{
	int ret;

	if (machine_is_tegratab() || machine_is_tegranote7c()) {
		/* InCharge Limit=3.136A, Battery Spec is 3.2A */
		ret = regmap_write(bq2419x->regmap,
				BQ2419X_CHRG_CTRL_REG, 0xA4);
		if (ret < 0) {
			dev_err(bq2419x->dev,
			"CHRG_CTRL_REG write failed %d\n", ret);
			return ret;
		}
	} else if (machine_is_roth()) {
		/* Configure Output Current Control to 2.25A*/
		ret = regmap_write(bq2419x->regmap,
				BQ2419X_CHRG_CTRL_REG, 0x6c);
		if (ret < 0) {
			dev_err(bq2419x->dev,
			"CHRG_CTRL_REG write failed %d\n", ret);
			return ret;
		}
	}

	if (bq2419x->chip_version == BQ24193_IC) {
		/* JEITA_ISET=20%*/
		ret = regmap_update_bits(bq2419x->regmap,
			BQ2419X_TIME_CTRL_REG, BQ2419X_JEITA_ISET_MASK,
			BQ2419X_JEITA_ISET_20);
		if (ret < 0) {
			dev_err(bq2419x->dev,
			"TIME_CTRL_REG update failed %d\n", ret);
			return ret;
		}
		/* JEITA_VSET=4.2V*/
		ret = regmap_update_bits(bq2419x->regmap,
			BQ2419X_MISC_OPER_REG, BQ2419X_JEITA_VSET_MASK,
			BQ2419X_JEITA_VSET_4_20V);
		if (ret < 0) {
			dev_err(bq2419x->dev,
			"MISC_OPER_REG update failed %d\n", ret);
			return ret;
		}
	}

	if (bq2419x->chg_complete_soc && bq2419x->soc_check) {
		/* Not use termination, will check SOC*/
		ret = regmap_update_bits(bq2419x->regmap,
			BQ2419X_TIME_CTRL_REG, 0x80, 0);
		if (ret < 0) {
			dev_err(bq2419x->dev,
			"TIME_CTRL_REG update failed %d\n", ret);
			return ret;
		}
	}

	/*
	 * Configure Input voltage limit reset to OTP value,
	 * and charging current to 500mA.
	 */
	ret = regmap_write(bq2419x->regmap, BQ2419X_INPUT_SRC_REG, 0x32);
	if (ret < 0)
		dev_err(bq2419x->dev, "INPUT_SRC_REG write failed %d\n", ret);

	return ret;
}

static int bq2419x_set_charging_current(struct regulator_dev *rdev,
					int min_uA, int max_uA)
{
	struct bq2419x_chip *bq_charger = rdev_get_drvdata(rdev);
	int ret = 0;
	int val;

	dev_info(bq_charger->dev, "Setting charging current %d\n", max_uA/1000);
	msleep(200);
	bq_charger->status = 0;

	ret = bq2419x_charger_enable(bq_charger);
	if (ret < 0)
		goto error;

	ret = regmap_read(bq_charger->regmap, BQ2419X_SYS_STAT_REG, &val);
	if (ret < 0)
		dev_err(bq_charger->dev, "error reading reg: 0x%x\n",
				BQ2419X_SYS_STAT_REG);

	if (max_uA == 0 && val != 0)
		return 0;

	bq_charger->in_current_limit = max_uA/1000;
	if ((val & BQ2419x_VBUS_STAT) == BQ2419x_VBUS_UNKNOWN) {
		bq_charger->in_current_limit = 500;
		bq_charger->status = 0;
	} else {
		bq_charger->status = 1;
	}
	ret = bq2419x_init(bq_charger);
	if (ret < 0)
		goto error;
	if (bq_charger->update_status)
		bq_charger->update_status(bq_charger->status, 0);
	return 0;
error:
	dev_err(bq_charger->dev, "Charger enable failed, err = %d\n", ret);
	return ret;
}

static struct regulator_ops bq2419x_tegra_regulator_ops = {
	.set_current_limit = bq2419x_set_charging_current,
};

static int bq2419x_reset_wdt(struct bq2419x_chip *bq2419x, const char *from)
{
	int ret = 0;
	unsigned int reg01;

	mutex_lock(&bq2419x->mutex);
	if (bq2419x->suspended)
		goto scrub;

	dev_info(bq2419x->dev, "%s() from %s()\n", __func__, from);

	ret = regmap_read(bq2419x->regmap, BQ2419X_PWR_ON_REG, &reg01);
	if (ret < 0) {
		dev_err(bq2419x->dev, "PWR_ON_REG read failed: %d\n", ret);
		goto scrub;
	}

	reg01 |= BIT(6);

	/* Write two times to make sure reset WDT */
	ret = regmap_write(bq2419x->regmap, BQ2419X_PWR_ON_REG, reg01);
	if (ret < 0) {
		dev_err(bq2419x->dev, "PWR_ON_REG write failed: %d\n", ret);
		goto scrub;
	}
	ret = regmap_write(bq2419x->regmap, BQ2419X_PWR_ON_REG, reg01);
	if (ret < 0) {
		dev_err(bq2419x->dev, "PWR_ON_REG write failed: %d\n", ret);
		goto scrub;
	}

scrub:
	mutex_unlock(&bq2419x->mutex);
	return ret;
}

static int bq2419x_fault_clear_sts(struct bq2419x_chip *bq2419x)
{
	int ret;
	unsigned int reg09;

	ret = regmap_read(bq2419x->regmap, BQ2419X_FAULT_REG, &reg09);
	if (ret < 0) {
		dev_err(bq2419x->dev, "FAULT_REG read failed: %d\n", ret);
		return ret;
	}

	ret = regmap_read(bq2419x->regmap, BQ2419X_FAULT_REG, &reg09);
	if (ret < 0)
		dev_err(bq2419x->dev, "FAULT_REG read failed: %d\n", ret);

	return ret;
}

static int bq2419x_watchdog_init(struct bq2419x_chip *bq2419x,
			int timeout, const char *from)
{
	int ret, val;
	unsigned int reg05;

	if (!timeout) {
		ret = regmap_update_bits(bq2419x->regmap, BQ2419X_TIME_CTRL_REG,
				BQ2419X_WD_MASK, 0);
		if (ret < 0)
			dev_err(bq2419x->dev,
				"TIME_CTRL_REG read failed: %d\n", ret);
		return ret;
	}

	if (timeout <= 60) {
		val = BQ2419X_WD_40ms;
		bq2419x->wdt_refresh_timeout = 25;
	} else if (timeout <= 120) {
		val = BQ2419X_WD_80ms;
		bq2419x->wdt_refresh_timeout = 50;
	} else {
		val = BQ2419X_WD_160ms;
		bq2419x->wdt_refresh_timeout = 125;
	}

	ret = regmap_read(bq2419x->regmap, BQ2419X_TIME_CTRL_REG, &reg05);
	if (ret < 0) {
		dev_err(bq2419x->dev,
			"TIME_CTRL_REG read failed:%d\n", ret);
		return ret;
	}

	if ((reg05 & BQ2419X_WD_MASK) != val) {
		ret = regmap_update_bits(bq2419x->regmap, BQ2419X_TIME_CTRL_REG,
				BQ2419X_WD_MASK, val);
		if (ret < 0) {
			dev_err(bq2419x->dev,
				"TIME_CTRL_REG read failed: %d\n", ret);
			return ret;
		}
	}

	/* Clear EN_HIZ */
	ret = regmap_update_bits(bq2419x->regmap,
		BQ2419X_INPUT_SRC_REG, BQ2419X_EN_HIZ, 0);
	if (ret < 0)
		dev_err(bq2419x->dev, "INPUT_SRC_REG update failed:%d\n", ret);

	ret = bq2419x_reset_wdt(bq2419x, from);
	if (ret < 0)
		dev_err(bq2419x->dev, "bq2419x_reset_wdt failed: %d\n", ret);

	return ret;
}

static void bq2419x_work_thread(struct kthread_work *work)
{
	struct bq2419x_chip *bq2419x = container_of(work,
			struct bq2419x_chip, bq_wdt_work);
	int ret;
	int val = 0;
	int soc;
	int vcell;
	s32 batt_current;

	for (;;) {
		if (bq2419x->stop_thread)
			return;

		if (bq2419x->chg_restart_timeout) {
			mutex_lock(&bq2419x->mutex);
			bq2419x->chg_restart_timeout--;
			if (!bq2419x->chg_restart_timeout) {
				dev_info(bq2419x->dev,
					"Charging Restart by timer.\n");
				ret = bq2419x_charger_disable(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"Charger disable failed %d", ret);
				mdelay(100);
				ret = bq2419x_charger_enable(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"Charger enable failed %d", ret);
				ret = bq2419x_charger_init(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"Charger init failed: %d\n", ret);
				ret = bq2419x_init(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"bq2419x init failed: %d\n", ret);

				ret = regmap_read(bq2419x->regmap,
					BQ2419X_SYS_STAT_REG, &val);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"SYS_STAT_REG read failed %d\n", ret);
				/*
				* Update Charging status based on STAT register
				*/
				if ((val & BQ2419x_CHRG_STATE_MASK) ==
					BQ2419x_CHRG_STATE_NOTCHARGING) {
					bq2419x->status = 0;
					if (bq2419x->update_status)
						bq2419x->update_status
							(bq2419x->status, 0);
					bq2419x->chg_restart_timeout =
						bq2419x->chg_restart_time /
						bq2419x->wdt_refresh_timeout;
				} else {
					bq2419x->status = 1;
					if (bq2419x->update_status)
						bq2419x->update_status
							(bq2419x->status, 0);
				}
			}

			if (bq2419x->suspended)
				bq2419x->chg_restart_timeout = 0;

			mutex_unlock(&bq2419x->mutex);
		}

		if (bq2419x->chg_complete_soc && bq2419x->soc_check) {
			mutex_lock(&bq2419x->mutex);
			soc = bq2419x->soc_check();

			/* Check voltage when complete soc is 100% */
			if ((bq2419x->chg_complete_soc >= FULL_CHARGE_SOC) &&
				bq2419x->vcell_check)
				vcell = bq2419x->vcell_check();
			else
				vcell = MAX_CHARING_VOLTAGE;

			/* Check current when complete soc is 100% */
			if ((bq2419x->chg_complete_soc >= FULL_CHARGE_SOC) &&
				bq2419x->current_check)
				batt_current = bq2419x->current_check();
			else
				batt_current = CHARING_COMPLETE_CURRENT;

			if ((soc >= bq2419x->chg_complete_soc) &&
				(vcell >= MAX_CHARING_VOLTAGE) &&
				(batt_current >= CHARING_COMPLETE_CURRENT) &&
				!chg_complete_check) {
				ret = regmap_read(bq2419x->regmap,
					BQ2419X_SYS_STAT_REG, &val);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"SYS_STAT_REG read failed %d\n", ret);

				if ((val & BQ2419x_CHRG_STATE_MASK) ==
					BQ2419x_CHRG_STATE_POST_CHARGE) {
					dev_info(bq2419x->dev,
						"Full charged Charging Stop\n");
					ret = bq2419x_charger_disable(bq2419x);
					if (ret < 0)
						dev_err(bq2419x->dev,
						"Charger disable failed %d",
						ret);

					bq2419x->chg_restart_timeout =
						bq2419x->chg_restart_time /
						bq2419x->wdt_refresh_timeout;

					chg_complete_check = 1;
					mdelay(100);
				}
			}

			if (chg_complete_check &&
				(vcell <= RECHARING_VOLTAGE ||
				soc < bq2419x->chg_complete_soc)) {
				dev_info(bq2419x->dev,
					"Charging Restart by voltage.\n");
				ret = bq2419x_charger_enable(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"Charger enable failed %d", ret);
				ret = bq2419x_charger_init(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"Charger init failed: %d\n", ret);
				ret = bq2419x_init(bq2419x);
				if (ret < 0)
					dev_err(bq2419x->dev,
					"bq2419x init failed: %d\n", ret);
			}
			mutex_unlock(&bq2419x->mutex);
		}

		/* When chg_complete_soc < 100 and charging done,
		   cut charger power */
		if ((bq2419x->chg_complete_soc < FULL_CHARGE_SOC) &&
			chg_complete_check) {
			/* Set EN_HIZ for cut charger power */
			ret = regmap_update_bits(bq2419x->regmap,
				BQ2419X_INPUT_SRC_REG, BQ2419X_EN_HIZ,
				BQ2419X_EN_HIZ);
		} else {
			/* Clear EN_HIZ */
			ret = regmap_update_bits(bq2419x->regmap,
				BQ2419X_INPUT_SRC_REG, BQ2419X_EN_HIZ, 0);
		}
		if (ret < 0)
			dev_err(bq2419x->dev,
				"INPUT_SRC_REG update failed:%d\n", ret);

		ret = bq2419x_reset_wdt(bq2419x, "THREAD");
		if (ret < 0)
			dev_err(bq2419x->dev,
				"bq2419x_reset_wdt failed: %d\n", ret);

		msleep(bq2419x->wdt_refresh_timeout * 1000);
	}
}

static int bq2419x_reset_safety_timer(struct bq2419x_chip *bq2419x)
{
	int ret;

	ret = regmap_update_bits(bq2419x->regmap, BQ2419X_TIME_CTRL_REG,
			BQ2419X_EN_SFT_TIMER_MASK, 0);
	if (ret < 0) {
		dev_err(bq2419x->dev,
				"TIME_CTRL_REG update failed: %d\n", ret);
		return ret;
	}

	ret = regmap_update_bits(bq2419x->regmap, BQ2419X_TIME_CTRL_REG,
			BQ2419X_EN_SFT_TIMER_MASK, BQ2419X_EN_SFT_TIMER_MASK);
	if (ret < 0)
		dev_err(bq2419x->dev,
				"TIME_CTRL_REG update failed: %d\n", ret);
	return ret;
}

static irqreturn_t bq2419x_irq(int irq, void *data)
{
	struct bq2419x_chip *bq2419x = data;
	int ret;
	unsigned int val;
	int check_chg_state = 0;

	ret = regmap_read(bq2419x->regmap, BQ2419X_FAULT_REG, &val);
	if (ret < 0) {
		dev_err(bq2419x->dev, "FAULT_REG read failed %d\n", ret);
		return ret;
	}

	dev_info(bq2419x->dev, "%s() Irq %d status 0x%02x\n",
		__func__, irq, val);

	if (val & BQ2419x_FAULT_WATCHDOG_FAULT) {
		dev_err(bq2419x->dev,
			"Charging Fault: Watchdog Timer Expired\n");
		ret = bq2419x_watchdog_init(bq2419x, bq2419x->wdt_time_sec,
						"ISR");
		if (ret < 0) {
			dev_err(bq2419x->dev, "BQWDT init failed %d\n", ret);
			return ret;
		}

		ret = bq2419x_charger_init(bq2419x);
		if (ret < 0) {
			dev_err(bq2419x->dev, "Charger init failed: %d\n", ret);
			return ret;
		}

		ret = bq2419x_init(bq2419x);
		if (ret < 0) {
			dev_err(bq2419x->dev, "bq2419x init failed: %d\n", ret);
			return ret;
		}
	}

	if (val & BQ2419x_FAULT_BOOST_FAULT)
		dev_err(bq2419x->dev, "Charging Fault: VBUS Overloaded\n");

	switch (val & BQ2419x_FAULT_CHRG_FAULT_MASK) {
	case BQ2419x_FAULT_CHRG_INPUT:
		dev_err(bq2419x->dev, "Charging Fault: "
				"Input Fault (VBUS OVP or VBAT<VBUS<3.8V)\n");
		chg_complete_check = 0;
		bq2419x->chg_restart_timeout = 0;
		break;
	case BQ2419x_FAULT_CHRG_THERMAL:
		dev_err(bq2419x->dev, "Charging Fault: Thermal shutdown\n");
		check_chg_state = 1;
		break;
	case BQ2419x_FAULT_CHRG_SAFTY:
		dev_err(bq2419x->dev,
			"Charging Fault: Safety timer expiration\n");
		bq2419x->chg_restart_timeout = bq2419x->chg_restart_time /
						bq2419x->wdt_refresh_timeout;
		ret = bq2419x_reset_safety_timer(bq2419x);
		if (ret < 0) {
			dev_err(bq2419x->dev, "Reset safety timer failed %d\n",
							ret);
			return ret;
		}

		check_chg_state = 1;
		break;
	default:
		break;
	}

	if (val & BQ2419x_FAULT_NTC_FAULT) {
		dev_err(bq2419x->dev, "Charging Fault: NTC fault %d\n",
				val & BQ2419x_FAULT_NTC_FAULT);
		check_chg_state = 1;
	}

	ret = bq2419x_fault_clear_sts(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "fault clear status failed %d\n", ret);
		return ret;
	}

	ret = regmap_read(bq2419x->regmap, BQ2419X_SYS_STAT_REG, &val);
	if (ret < 0) {
		dev_err(bq2419x->dev, "SYS_STAT_REG read failed %d\n", ret);
		return ret;
	}

	if ((val & BQ2419x_CHRG_STATE_MASK) ==
				BQ2419x_CHRG_STATE_CHARGE_DONE) {
		bq2419x->chg_restart_timeout = bq2419x->chg_restart_time /
						bq2419x->wdt_refresh_timeout;
		dev_info(bq2419x->dev, "Charging completed\n");
	}

	/*
	* Update Charging status based on STAT register
	*/
	if (check_chg_state) {
		if ((val & BQ2419x_CHRG_STATE_MASK) ==
				BQ2419x_CHRG_STATE_NOTCHARGING) {
			bq2419x->status = 0;
			if (bq2419x->update_status)
				bq2419x->update_status(bq2419x->status, 0);
		}
	}

	return IRQ_HANDLED;
}

static int bq2419x_init_charger_regulator(struct bq2419x_chip *bq2419x,
		struct bq2419x_platform_data *pdata)
{
	int ret = 0;

	if (!pdata->bcharger_pdata) {
		dev_err(bq2419x->dev, "No charger platform data\n");
		return 0;
	}

	bq2419x->chg_reg_desc.name  = "bq2419x-charger";
	bq2419x->chg_reg_desc.ops   = &bq2419x_tegra_regulator_ops;
	bq2419x->chg_reg_desc.type  = REGULATOR_CURRENT;
	bq2419x->chg_reg_desc.owner = THIS_MODULE;

	bq2419x->chg_reg_init_data.supply_regulator	= NULL;
	bq2419x->chg_reg_init_data.regulator_init	= NULL;
	bq2419x->chg_reg_init_data.num_consumer_supplies =
				pdata->bcharger_pdata->num_consumer_supplies;
	bq2419x->chg_reg_init_data.consumer_supplies	=
				pdata->bcharger_pdata->consumer_supplies;
	bq2419x->chg_reg_init_data.driver_data		= bq2419x;
	bq2419x->chg_reg_init_data.constraints.name	= "bq2419x-charger";
	bq2419x->chg_reg_init_data.constraints.min_uA	= 0;
	bq2419x->chg_reg_init_data.constraints.max_uA	=
			pdata->bcharger_pdata->max_charge_current_mA * 1000;

	bq2419x->chg_reg_init_data.constraints.valid_modes_mask =
						REGULATOR_MODE_NORMAL |
						REGULATOR_MODE_STANDBY;

	bq2419x->chg_reg_init_data.constraints.valid_ops_mask =
						REGULATOR_CHANGE_MODE |
						REGULATOR_CHANGE_STATUS |
						REGULATOR_CHANGE_CURRENT;

	bq2419x->chg_rdev = regulator_register(&bq2419x->chg_reg_desc,
				bq2419x->dev, &bq2419x->chg_reg_init_data,
				bq2419x, NULL);
	if (IS_ERR(bq2419x->chg_rdev)) {
		ret = PTR_ERR(bq2419x->chg_rdev);
		dev_err(bq2419x->dev,
			"vbus-charger regulator register failed %d\n", ret);
	}
	return ret;
}

static int bq2419x_init_vbus_regulator(struct bq2419x_chip *bq2419x,
		struct bq2419x_platform_data *pdata)
{
	int ret = 0;

	if (!pdata->vbus_pdata) {
		dev_err(bq2419x->dev, "No vbus platform data\n");
		return 0;
	}

	bq2419x->gpio_otg_iusb = pdata->vbus_pdata->gpio_otg_iusb;
	bq2419x->vbus_reg_desc.name = "bq2419x-vbus";
	bq2419x->vbus_reg_desc.ops = &bq2419x_vbus_ops;
	bq2419x->vbus_reg_desc.type = REGULATOR_VOLTAGE;
	bq2419x->vbus_reg_desc.owner = THIS_MODULE;

	bq2419x->vbus_reg_init_data.supply_regulator	= NULL;
	bq2419x->vbus_reg_init_data.regulator_init	= NULL;
	bq2419x->vbus_reg_init_data.num_consumer_supplies	=
				pdata->vbus_pdata->num_consumer_supplies;
	bq2419x->vbus_reg_init_data.consumer_supplies	=
				pdata->vbus_pdata->consumer_supplies;
	bq2419x->vbus_reg_init_data.driver_data		= bq2419x;

	bq2419x->vbus_reg_init_data.constraints.name	= "bq2419x-vbus";
	bq2419x->vbus_reg_init_data.constraints.min_uV	= 0;
	bq2419x->vbus_reg_init_data.constraints.max_uV	= 5000000,
	bq2419x->vbus_reg_init_data.constraints.valid_modes_mask =
					REGULATOR_MODE_NORMAL |
					REGULATOR_MODE_STANDBY;
	bq2419x->vbus_reg_init_data.constraints.valid_ops_mask =
					REGULATOR_CHANGE_MODE |
					REGULATOR_CHANGE_STATUS |
					REGULATOR_CHANGE_VOLTAGE;

	if (gpio_is_valid(bq2419x->gpio_otg_iusb)) {
		ret = gpio_request_one(bq2419x->gpio_otg_iusb,
				GPIOF_OUT_INIT_HIGH, dev_name(bq2419x->dev));
		if (ret < 0) {
			dev_err(bq2419x->dev, "gpio request failed  %d\n", ret);
			return ret;
		}
	}

	/* Register the regulators */
	bq2419x->vbus_rdev = regulator_register(&bq2419x->vbus_reg_desc,
			bq2419x->dev, &bq2419x->vbus_reg_init_data,
			bq2419x, NULL);
	if (IS_ERR(bq2419x->vbus_rdev)) {
		ret = PTR_ERR(bq2419x->vbus_rdev);
		dev_err(bq2419x->dev,
			"VBUS regulator register failed %d\n", ret);
		goto scrub;
	}

	/* Disable the VBUS regulator and enable charging */
	ret = bq2419x_charger_enable(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "Charging enable failed %d", ret);
		goto scrub_reg;
	}
	return ret;

scrub_reg:
	regulator_unregister(bq2419x->vbus_rdev);
	bq2419x->vbus_rdev = NULL;
scrub:
	if (gpio_is_valid(bq2419x->gpio_otg_iusb))
		gpio_free(bq2419x->gpio_otg_iusb);
	return ret;
}

static int bq2419x_show_chip_version(struct bq2419x_chip *bq2419x)
{
	int ret;
	unsigned int val;

	ret = regmap_read(bq2419x->regmap, BQ2419X_REVISION_REG, &val);
	if (ret < 0) {
		dev_err(bq2419x->dev, "REVISION_REG read failed: %d\n", ret);
		return ret;
	}

	val &= BQ2419X_IC_VER_MASK;

	if (val == BQ24190_IC_VER) {
		bq2419x->chip_version = BQ24190_IC;
		dev_info(bq2419x->dev, "chip type BQ24190 detected\n");
	} else if (val == BQ24192_IC_VER) {
		bq2419x->chip_version = BQ24192_IC;
		dev_info(bq2419x->dev, "chip type BQ24192 detected\n");
	} else if (val == BQ24193_IC_VER) {
		bq2419x->chip_version = BQ24193_IC;
		dev_info(bq2419x->dev, "chip type BQ24193 detected\n");
	} else if (val == BQ24192i_IC_VER) {
		bq2419x->chip_version = BQ24192i_IC;
		dev_info(bq2419x->dev, "chip type BQ2419Xi detected\n");
	}
	return 0;
}

static int bq2419x_wakealarm(struct bq2419x_chip *bq2419x, int time_sec)
{
	int ret;
	unsigned long now;
	struct rtc_wkalrm alm;
	int alarm_time = time_sec;

	if (!alarm_time)
		return 0;

	alm.enabled = true;
	ret = rtc_read_time(bq2419x->rtc, &alm.time);
	if (ret < 0) {
		dev_err(bq2419x->dev, "RTC read time failed %d\n", ret);
		return ret;
	}
	rtc_tm_to_time(&alm.time, &now);

	rtc_time_to_tm(now + alarm_time, &alm.time);
	ret = rtc_set_alarm(bq2419x->rtc, &alm);
	if (ret < 0) {
		dev_err(bq2419x->dev, "RTC set alarm failed %d\n", ret);
		alm.enabled = false;
		return ret;
	}
	alm.enabled = false;
	return 0;
}

static s32 show_chg_complete_soc(struct device *dev,
				  struct device_attribute *attr,
				  char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct bq2419x_chip *bq2419x = i2c_get_clientdata(client);
	return sprintf(buf, "%d\n", bq2419x->chg_complete_soc);
}

static s32 store_chg_complete_soc(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct bq2419x_chip *bq2419x = i2c_get_clientdata(client);
	int soc;

	if ((sscanf(buf, "%d", &soc) != 1) || soc < 60 || soc > 100)
		return -EINVAL;

	mutex_lock(&bq2419x->mutex);
	/* forced check re-charging*/
	chg_complete_check = 1;
	bq2419x->chg_complete_soc = soc;
	mutex_unlock(&bq2419x->mutex);

	return count;
}

static struct device_attribute bq2419x_attrs[] = {
	__ATTR(chg_complete_soc, 0644,
		show_chg_complete_soc, store_chg_complete_soc),
};

static int __devinit bq2419x_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct bq2419x_chip *bq2419x;
	struct bq2419x_platform_data *pdata;
	int ret = 0;
	int i;

	pdata = client->dev.platform_data;
	if (!pdata) {
		dev_err(&client->dev, "No Platform data");
		return -EINVAL;
	}

	bq2419x = devm_kzalloc(&client->dev, sizeof(*bq2419x), GFP_KERNEL);
	if (!bq2419x) {
		dev_err(&client->dev, "Memory allocation failed\n");
		return -ENOMEM;
	}

	bq2419x->regmap = devm_regmap_init_i2c(client, &bq2419x_regmap_config);
	if (IS_ERR(bq2419x->regmap)) {
		ret = PTR_ERR(bq2419x->regmap);
		dev_err(&client->dev, "regmap init failed with err %d\n", ret);
		return ret;
	}

	bq2419x->dev = &client->dev;

	if (pdata->bcharger_pdata) {
		bq2419x->update_status	= pdata->bcharger_pdata->update_status;
		bq2419x->soc_check	= pdata->bcharger_pdata->soc_check;
		bq2419x->vcell_check	= pdata->bcharger_pdata->vcell_check;
		bq2419x->current_check	= pdata->bcharger_pdata->current_check;
		bq2419x->rtc_alarm_time	= pdata->bcharger_pdata->rtc_alarm_time;
		bq2419x->wdt_time_sec	= pdata->bcharger_pdata->wdt_timeout;
		bq2419x->chg_restart_time =
				pdata->bcharger_pdata->chg_restart_time;
		bq2419x->chg_complete_soc =
				pdata->bcharger_pdata->chg_complete_soc;
		bq2419x->chg_enable	= true;
	}

	bq2419x->wdt_refresh_timeout = 25;
	i2c_set_clientdata(client, bq2419x);
	bq2419x->irq = client->irq;

	if (bq2419x->rtc_alarm_time)
		bq2419x->rtc = alarmtimer_get_rtcdev();

	mutex_init(&bq2419x->mutex);
	bq2419x->suspended = 0;
	bq2419x->chg_restart_timeout = 0;

	ret = bq2419x_show_chip_version(bq2419x);
	if (ret < 0) {
		dev_err(&client->dev, "version read failed %d\n", ret);
		return ret;
	}

	ret = bq2419x_charger_init(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "Charger init failed: %d\n", ret);
		return ret;
	}

	ret = bq2419x_init_charger_regulator(bq2419x, pdata);
	if (ret < 0) {
		dev_err(&client->dev,
			"Charger regualtor init failed %d\n", ret);
		return ret;
	}

	ret = bq2419x_init_vbus_regulator(bq2419x, pdata);
	if (ret < 0) {
		dev_err(&client->dev,
			"VBUS regualtor init failed %d\n", ret);
		goto scrub_chg_reg;
	}

	init_kthread_worker(&bq2419x->bq_kworker);
	bq2419x->bq_kworker_task = kthread_run(kthread_worker_fn,
				&bq2419x->bq_kworker,
				dev_name(bq2419x->dev));
	if (IS_ERR(bq2419x->bq_kworker_task)) {
		ret = PTR_ERR(bq2419x->bq_kworker_task);
		dev_err(&client->dev, "Kworker task creation failed %d\n", ret);
		goto scrub_vbus_reg;
	}

	init_kthread_work(&bq2419x->bq_wdt_work, bq2419x_work_thread);
	sched_setscheduler(bq2419x->bq_kworker_task,
			SCHED_FIFO, &bq2419x_param);
	queue_kthread_work(&bq2419x->bq_kworker, &bq2419x->bq_wdt_work);

	ret = bq2419x_watchdog_init(bq2419x, bq2419x->wdt_time_sec, "PROBE");
	if (ret < 0) {
		dev_err(bq2419x->dev, "BQWDT init failed %d\n", ret);
		goto scrub_kthread;
	}

	ret = bq2419x_fault_clear_sts(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "fault clear status failed %d\n", ret);
		goto scrub_kthread;
	}

	ret = request_threaded_irq(bq2419x->irq, NULL,
		bq2419x_irq, IRQF_TRIGGER_FALLING,
			dev_name(bq2419x->dev), bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "request IRQ %d fail, err = %d\n",
				bq2419x->irq, ret);
		goto scrub_kthread;
	}

	/* enable charging */
	ret = bq2419x_charger_enable(bq2419x);
	if (ret < 0)
		goto scrub_irq;

	/* create sysfs node */
	for (i = 0; i < ARRAY_SIZE(bq2419x_attrs); i++) {
		ret = device_create_file(&client->dev, &bq2419x_attrs[i]);
		if (ret)
			goto scrub_file;
	}

	return 0;
scrub_file:
	for (i = 0; i < ARRAY_SIZE(bq2419x_attrs); i++)
		device_remove_file(&client->dev, &bq2419x_attrs[i]);
scrub_irq:
	free_irq(bq2419x->irq, bq2419x);
scrub_kthread:
	bq2419x->stop_thread = true;
	flush_kthread_worker(&bq2419x->bq_kworker);
	kthread_stop(bq2419x->bq_kworker_task);
scrub_vbus_reg:
	regulator_unregister(bq2419x->vbus_rdev);
scrub_chg_reg:
	regulator_unregister(bq2419x->chg_rdev);
	mutex_destroy(&bq2419x->mutex);
	return ret;
}

static int __devexit bq2419x_remove(struct i2c_client *client)
{
	struct bq2419x_chip *bq2419x = i2c_get_clientdata(client);
	int i;

	free_irq(bq2419x->irq, bq2419x);
	bq2419x->stop_thread = true;
	flush_kthread_worker(&bq2419x->bq_kworker);
	kthread_stop(bq2419x->bq_kworker_task);
	regulator_unregister(bq2419x->vbus_rdev);
	regulator_unregister(bq2419x->chg_rdev);
	for (i = 0; i < ARRAY_SIZE(bq2419x_attrs); i++)
		device_remove_file(&client->dev, &bq2419x_attrs[i]);
	mutex_destroy(&bq2419x->mutex);
	return 0;
}

static void bq2419x_shutdown(struct i2c_client *client)
{
	int ret = 0;
	struct bq2419x_chip *bq2419x = i2c_get_clientdata(client);
	int alarm_time = bq2419x->rtc_alarm_time;

	if (bq2419x->irq)
		disable_irq(bq2419x->irq);

	if (alarm_time && !bq2419x->rtc)
		bq2419x->rtc = alarmtimer_get_rtcdev();

	if (alarm_time && (bq2419x->in_current_limit > 500)) {
		dev_info(bq2419x->dev, "HighCurrent %dmA charger is connectd\n",
			bq2419x->in_current_limit);
		/* Clear EN_HIZ */
		ret = regmap_update_bits(bq2419x->regmap,
			BQ2419X_INPUT_SRC_REG, BQ2419X_EN_HIZ, 0);
		if (ret < 0)
			dev_err(bq2419x->dev,
				"INPUT_SRC_REG update failed:%d\n", ret);
		ret = bq2419x_reset_wdt(bq2419x, "shutdown");
		if (ret < 0)
			dev_err(bq2419x->dev,
				"bq2419x_reset_wdt failed: %d\n", ret);
		alarm_time = 20;
	}

	mutex_lock(&bq2419x->mutex);
	bq2419x->suspended = 1;
	mutex_unlock(&bq2419x->mutex);

	ret = bq2419x_charger_enable(bq2419x);
	if (ret < 0)
		dev_err(bq2419x->dev, "Charger enable failed %d", ret);

	if (alarm_time && (bq2419x->in_current_limit <= 500)) {
		/* Configure charging current to 500mA */
		ret = regmap_write(bq2419x->regmap,
				BQ2419X_INPUT_SRC_REG, 0x32);
		if (ret < 0)
			dev_err(bq2419x->dev,
				"INPUT_SRC_REG write failed %d\n", ret);
	}

	ret = bq2419x_wakealarm(bq2419x, alarm_time);
	if (ret < 0)
		dev_err(bq2419x->dev, "RTC wake alarm config failed %d\n", ret);
}

#ifdef CONFIG_PM_SLEEP
static int bq2419x_suspend(struct device *dev)
{
	int ret = 0;
	struct bq2419x_chip *bq2419x = dev_get_drvdata(dev);

	mutex_lock(&bq2419x->mutex);
	bq2419x->suspended = 1;
	mutex_unlock(&bq2419x->mutex);
	disable_irq(bq2419x->irq);
	ret = bq2419x_charger_enable(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "Charger enable failed %d", ret);
		return ret;
	}

	/* Configure charging current to 500mA */
	ret = regmap_write(bq2419x->regmap, BQ2419X_INPUT_SRC_REG, 0x32);
	if (ret < 0) {
		dev_err(bq2419x->dev, "INPUT_SRC_REG write failed %d\n", ret);
		return ret;
	}

	return 0;
}

static int bq2419x_resume(struct device *dev)
{
	int ret = 0;
	struct bq2419x_chip *bq2419x = dev_get_drvdata(dev);
	unsigned int val;

	ret = regmap_read(bq2419x->regmap, BQ2419X_FAULT_REG, &val);
	if (ret < 0) {
		dev_err(bq2419x->dev, "FAULT_REG read failed %d\n", ret);
		return ret;
	}

	if (val & BQ2419x_FAULT_WATCHDOG_FAULT) {
		dev_err(bq2419x->dev,
			"Charging Fault: Watchdog Timer Expired\n");

		ret = bq2419x_watchdog_init(bq2419x, bq2419x->wdt_time_sec,
						"RESUME");
		if (ret < 0) {
			dev_err(bq2419x->dev, "BQWDT init failed %d\n", ret);
			return ret;
		}
	}

	ret = bq2419x_fault_clear_sts(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "fault clear status failed %d\n", ret);
		return ret;
	}

	ret = bq2419x_charger_init(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "Charger init failed: %d\n", ret);
		return ret;
	}

	ret = bq2419x_init(bq2419x);
	if (ret < 0) {
		dev_err(bq2419x->dev, "bq2419x init failed: %d\n", ret);
		return ret;
	}

	mutex_lock(&bq2419x->mutex);
	bq2419x->suspended = 0;
	mutex_unlock(&bq2419x->mutex);
	if (gpio_is_valid(bq2419x->gpio_otg_iusb))
		gpio_set_value(bq2419x->gpio_otg_iusb, 1);

	enable_irq(bq2419x->irq);
	return 0;
};
#endif

static const struct dev_pm_ops bq2419x_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(bq2419x_suspend,
				bq2419x_resume)
};

static const struct i2c_device_id bq2419x_id[] = {
	{.name = "bq2419x",},
	{},
};
MODULE_DEVICE_TABLE(i2c, bq2419x_id);

static struct i2c_driver bq2419x_i2c_driver = {
	.driver = {
		.name	= "bq2419x",
		.owner	= THIS_MODULE,
		.pm = &bq2419x_pm_ops,
	},
	.probe		= bq2419x_probe,
	.remove		= __devexit_p(bq2419x_remove),
	.shutdown	= bq2419x_shutdown,
	.id_table	= bq2419x_id,
};

static int __init bq2419x_module_init(void)
{
	return i2c_add_driver(&bq2419x_i2c_driver);
}
subsys_initcall(bq2419x_module_init);

static void __exit bq2419x_cleanup(void)
{
	i2c_del_driver(&bq2419x_i2c_driver);
}
module_exit(bq2419x_cleanup);

MODULE_DESCRIPTION("BQ24190/BQ24192/BQ24192i/BQ24193 battery charger driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_AUTHOR("Syed Rafiuddin <srafiuddin@nvidia.com");
MODULE_LICENSE("GPL v2");