drivers/power/bq24257_charger.c - kernel/msm-4.19 - Gitiles

 /*
  * TI BQ24257 charger driver
  *
  * Copyright (C) 2015 Intel Corporation
  *
  * 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.
  *
  */

 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/power_supply.h>
 #include <linux/regmap.h>
 #include <linux/types.h>
 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>

 #include <linux/acpi.h>
 #include <linux/of.h>

 #define BQ24257_REG_1			0x00
 #define BQ24257_REG_2			0x01
 #define BQ24257_REG_3			0x02
 #define BQ24257_REG_4			0x03
 #define BQ24257_REG_5			0x04
 #define BQ24257_REG_6			0x05
 #define BQ24257_REG_7			0x06

 #define BQ24257_MANUFACTURER		"Texas Instruments"
 #define BQ24257_PG_GPIO			"pg"

 #define BQ24257_ILIM_SET_DELAY		1000	/* msec */

 enum bq24257_fields {
 	F_WD_FAULT, F_WD_EN, F_STAT, F_FAULT,			    /* REG 1 */
 	F_RESET, F_IILIMIT, F_EN_STAT, F_EN_TERM, F_CE, F_HZ_MODE,  /* REG 2 */
 	F_VBAT, F_USB_DET,					    /* REG 3 */
 	F_ICHG, F_ITERM,					    /* REG 4 */
 	F_LOOP_STATUS, F_LOW_CHG, F_DPDM_EN, F_CE_STATUS, F_VINDPM, /* REG 5 */
 	F_X2_TMR_EN, F_TMR, F_SYSOFF, F_TS_STAT,		    /* REG 6 */
 	F_VOVP, F_CLR_VDP, F_FORCE_BATDET, F_FORCE_PTM,		    /* REG 7 */

 	F_MAX_FIELDS
 };

 /* initial field values, converted from uV/uA */
 struct bq24257_init_data {
 	u8 ichg;	/* charge current      */
 	u8 vbat;	/* regulation voltage  */
 	u8 iterm;	/* termination current */
 };

 struct bq24257_state {
 	u8 status;
 	u8 fault;
 	bool power_good;
 };

 struct bq24257_device {
 	struct i2c_client *client;
 	struct device *dev;
 	struct power_supply *charger;

 	struct regmap *rmap;
 	struct regmap_field *rmap_fields[F_MAX_FIELDS];

 	struct gpio_desc *pg;

 	struct delayed_work iilimit_setup_work;

 	struct bq24257_init_data init_data;
 	struct bq24257_state state;

 	struct mutex lock; /* protect state data */
 };

 static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
 	case BQ24257_REG_2:
 	case BQ24257_REG_4:
 		return false;

 	default:
 		return true;
 	}
 }

 static const struct regmap_config bq24257_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,

 	.max_register = BQ24257_REG_7,
 	.cache_type = REGCACHE_RBTREE,

 	.volatile_reg = bq24257_is_volatile_reg,
 };

 static const struct reg_field bq24257_reg_fields[] = {
 	/* REG 1 */
 	[F_WD_FAULT]		= REG_FIELD(BQ24257_REG_1, 7, 7),
 	[F_WD_EN]		= REG_FIELD(BQ24257_REG_1, 6, 6),
 	[F_STAT]		= REG_FIELD(BQ24257_REG_1, 4, 5),
 	[F_FAULT]		= REG_FIELD(BQ24257_REG_1, 0, 3),
 	/* REG 2 */
 	[F_RESET]		= REG_FIELD(BQ24257_REG_2, 7, 7),
 	[F_IILIMIT]		= REG_FIELD(BQ24257_REG_2, 4, 6),
 	[F_EN_STAT]		= REG_FIELD(BQ24257_REG_2, 3, 3),
 	[F_EN_TERM]		= REG_FIELD(BQ24257_REG_2, 2, 2),
 	[F_CE]			= REG_FIELD(BQ24257_REG_2, 1, 1),
 	[F_HZ_MODE]		= REG_FIELD(BQ24257_REG_2, 0, 0),
 	/* REG 3 */
 	[F_VBAT]		= REG_FIELD(BQ24257_REG_3, 2, 7),
 	[F_USB_DET]		= REG_FIELD(BQ24257_REG_3, 0, 1),
 	/* REG 4 */
 	[F_ICHG]		= REG_FIELD(BQ24257_REG_4, 3, 7),
 	[F_ITERM]		= REG_FIELD(BQ24257_REG_4, 0, 2),
 	/* REG 5 */
 	[F_LOOP_STATUS]		= REG_FIELD(BQ24257_REG_5, 6, 7),
 	[F_LOW_CHG]		= REG_FIELD(BQ24257_REG_5, 5, 5),
 	[F_DPDM_EN]		= REG_FIELD(BQ24257_REG_5, 4, 4),
 	[F_CE_STATUS]		= REG_FIELD(BQ24257_REG_5, 3, 3),
 	[F_VINDPM]		= REG_FIELD(BQ24257_REG_5, 0, 2),
 	/* REG 6 */
 	[F_X2_TMR_EN]		= REG_FIELD(BQ24257_REG_6, 7, 7),
 	[F_TMR]			= REG_FIELD(BQ24257_REG_6, 5, 6),
 	[F_SYSOFF]		= REG_FIELD(BQ24257_REG_6, 4, 4),
 	[F_TS_STAT]		= REG_FIELD(BQ24257_REG_6, 0, 2),
 	/* REG 7 */
 	[F_VOVP]		= REG_FIELD(BQ24257_REG_7, 5, 7),
 	[F_CLR_VDP]		= REG_FIELD(BQ24257_REG_7, 4, 4),
 	[F_FORCE_BATDET]	= REG_FIELD(BQ24257_REG_7, 3, 3),
 	[F_FORCE_PTM]		= REG_FIELD(BQ24257_REG_7, 2, 2)
 };

 static const u32 bq24257_vbat_map[] = {
 	3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
 	3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
 	3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
 	3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
 	4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
 	4300000, 4320000, 4340000, 4360000, 4380000, 4400000, 4420000, 4440000
 };

 #define BQ24257_VBAT_MAP_SIZE		ARRAY_SIZE(bq24257_vbat_map)

 static const u32 bq24257_ichg_map[] = {
 	500000, 550000, 600000, 650000, 700000, 750000, 800000, 850000, 900000,
 	950000, 1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000,
 	1350000, 1400000, 1450000, 1500000, 1550000, 1600000, 1650000, 1700000,
 	1750000, 1800000, 1850000, 1900000, 1950000, 2000000
 };

 #define BQ24257_ICHG_MAP_SIZE		ARRAY_SIZE(bq24257_ichg_map)

 static const u32 bq24257_iterm_map[] = {
 	50000, 75000, 100000, 125000, 150000, 175000, 200000, 225000
 };

 #define BQ24257_ITERM_MAP_SIZE		ARRAY_SIZE(bq24257_iterm_map)

 static int bq24257_field_read(struct bq24257_device *bq,
 			      enum bq24257_fields field_id)
 {
 	int ret;
 	int val;

 	ret = regmap_field_read(bq->rmap_fields[field_id], &val);
 	if (ret < 0)
 		return ret;

 	return val;
 }

 static int bq24257_field_write(struct bq24257_device *bq,
 			       enum bq24257_fields field_id, u8 val)
 {
 	return regmap_field_write(bq->rmap_fields[field_id], val);
 }

 static u8 bq24257_find_idx(u32 value, const u32 *map, u8 map_size)
 {
 	u8 idx;

 	for (idx = 1; idx < map_size; idx++)
 		if (value < map[idx])
 			break;

 	return idx - 1;
 }

 enum bq24257_status {
 	STATUS_READY,
 	STATUS_CHARGE_IN_PROGRESS,
 	STATUS_CHARGE_DONE,
 	STATUS_FAULT,
 };

 enum bq24257_fault {
 	FAULT_NORMAL,
 	FAULT_INPUT_OVP,
 	FAULT_INPUT_UVLO,
 	FAULT_SLEEP,
 	FAULT_BAT_TS,
 	FAULT_BAT_OVP,
 	FAULT_TS,
 	FAULT_TIMER,
 	FAULT_NO_BAT,
 	FAULT_ISET,
 	FAULT_INPUT_LDO_LOW,
 };

 static int bq24257_power_supply_get_property(struct power_supply *psy,
 					     enum power_supply_property psp,
 					     union power_supply_propval *val)
 {
 	struct bq24257_device *bq = power_supply_get_drvdata(psy);
 	struct bq24257_state state;

 	mutex_lock(&bq->lock);
 	state = bq->state;
 	mutex_unlock(&bq->lock);

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		if (!state.power_good)
 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 		else if (state.status == STATUS_READY)
 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 		else if (state.status == STATUS_CHARGE_IN_PROGRESS)
 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
 		else if (state.status == STATUS_CHARGE_DONE)
 			val->intval = POWER_SUPPLY_STATUS_FULL;
 		else
 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 		break;

 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		val->strval = BQ24257_MANUFACTURER;
 		break;

 	case POWER_SUPPLY_PROP_ONLINE:
 		val->intval = state.power_good;
 		break;

 	case POWER_SUPPLY_PROP_HEALTH:
 		switch (state.fault) {
 		case FAULT_NORMAL:
 			val->intval = POWER_SUPPLY_HEALTH_GOOD;
 			break;

 		case FAULT_INPUT_OVP:
 		case FAULT_BAT_OVP:
 			val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 			break;

 		case FAULT_TS:
 		case FAULT_BAT_TS:
 			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 			break;

 		case FAULT_TIMER:
 			val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
 			break;

 		default:
 			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 			break;
 		}

 		break;

 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
 		val->intval = bq24257_ichg_map[bq->init_data.ichg];
 		break;

 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
 		val->intval = bq24257_ichg_map[BQ24257_ICHG_MAP_SIZE - 1];
 		break;

 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
 		val->intval = bq24257_vbat_map[bq->init_data.vbat];
 		break;

 	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
 		val->intval = bq24257_vbat_map[BQ24257_VBAT_MAP_SIZE - 1];
 		break;

 	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
 		val->intval = bq24257_iterm_map[bq->init_data.iterm];
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int bq24257_get_chip_state(struct bq24257_device *bq,
 				  struct bq24257_state *state)
 {
 	int ret;

 	ret = bq24257_field_read(bq, F_STAT);
 	if (ret < 0)
 		return ret;

 	state->status = ret;

 	ret = bq24257_field_read(bq, F_FAULT);
 	if (ret < 0)
 		return ret;

 	state->fault = ret;

 	state->power_good = !gpiod_get_value_cansleep(bq->pg);

 	return 0;
 }

 static bool bq24257_state_changed(struct bq24257_device *bq,
 				  struct bq24257_state *new_state)
 {
 	int ret;

 	mutex_lock(&bq->lock);
 	ret = (bq->state.status != new_state->status ||
 	       bq->state.fault != new_state->fault ||
 	       bq->state.power_good != new_state->power_good);
 	mutex_unlock(&bq->lock);

 	return ret;
 }

 enum bq24257_loop_status {
 	LOOP_STATUS_NONE,
 	LOOP_STATUS_IN_DPM,
 	LOOP_STATUS_IN_CURRENT_LIMIT,
 	LOOP_STATUS_THERMAL,
 };

 enum bq24257_in_ilimit {
 	IILIMIT_100,
 	IILIMIT_150,
 	IILIMIT_500,
 	IILIMIT_900,
 	IILIMIT_1500,
 	IILIMIT_2000,
 	IILIMIT_EXT,
 	IILIMIT_NONE,
 };

 enum bq24257_port_type {
 	PORT_TYPE_DCP,		/* Dedicated Charging Port */
 	PORT_TYPE_CDP,		/* Charging Downstream Port */
 	PORT_TYPE_SDP,		/* Standard Downstream Port */
 	PORT_TYPE_NON_STANDARD,
 };

 enum bq24257_safety_timer {
 	SAFETY_TIMER_45,
 	SAFETY_TIMER_360,
 	SAFETY_TIMER_540,
 	SAFETY_TIMER_NONE,
 };

 static int bq24257_iilimit_autoset(struct bq24257_device *bq)
 {
 	int loop_status;
 	int iilimit;
 	int port_type;
 	int ret;
 	const u8 new_iilimit[] = {
 		[PORT_TYPE_DCP] = IILIMIT_2000,
 		[PORT_TYPE_CDP] = IILIMIT_2000,
 		[PORT_TYPE_SDP] = IILIMIT_500,
 		[PORT_TYPE_NON_STANDARD] = IILIMIT_500
 	};

 	ret = bq24257_field_read(bq, F_LOOP_STATUS);
 	if (ret < 0)
 		goto error;

 	loop_status = ret;

 	ret = bq24257_field_read(bq, F_IILIMIT);
 	if (ret < 0)
 		goto error;

 	iilimit = ret;

 	/*
 	 * All USB ports should be able to handle 500mA. If not, DPM will lower
 	 * the charging current to accommodate the power source. No need to set
 	 * a lower IILIMIT value.
 	 */
 	if (loop_status == LOOP_STATUS_IN_DPM && iilimit == IILIMIT_500)
 		return 0;

 	ret = bq24257_field_read(bq, F_USB_DET);
 	if (ret < 0)
 		goto error;

 	port_type = ret;

 	ret = bq24257_field_write(bq, F_IILIMIT, new_iilimit[port_type]);
 	if (ret < 0)
 		goto error;

 	ret = bq24257_field_write(bq, F_TMR, SAFETY_TIMER_360);
 	if (ret < 0)
 		goto error;

 	ret = bq24257_field_write(bq, F_CLR_VDP, 1);
 	if (ret < 0)
 		goto error;

 	dev_dbg(bq->dev, "port/loop = %d/%d -> iilimit = %d\n",
 		port_type, loop_status, new_iilimit[port_type]);

 	return 0;

 error:
 	dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
 	return ret;
 }

 static void bq24257_iilimit_setup_work(struct work_struct *work)
 {
 	struct bq24257_device *bq = container_of(work, struct bq24257_device,
 						 iilimit_setup_work.work);

 	bq24257_iilimit_autoset(bq);
 }

 static void bq24257_handle_state_change(struct bq24257_device *bq,
 					struct bq24257_state *new_state)
 {
 	int ret;
 	struct bq24257_state old_state;

 	mutex_lock(&bq->lock);
 	old_state = bq->state;
 	mutex_unlock(&bq->lock);

 	if (!new_state->power_good) {
 		dev_dbg(bq->dev, "Power removed\n");
 		cancel_delayed_work_sync(&bq->iilimit_setup_work);

 		/* activate D+/D- port detection algorithm */
 		ret = bq24257_field_write(bq, F_DPDM_EN, 1);
 		if (ret < 0)
 			goto error;

 		/* reset input current limit */
 		ret = bq24257_field_write(bq, F_IILIMIT, IILIMIT_500);
 		if (ret < 0)
 			goto error;
 	} else if (!old_state.power_good) {
 		dev_dbg(bq->dev, "Power inserted\n");

 		/* configure input current limit */
 		schedule_delayed_work(&bq->iilimit_setup_work,
 				      msecs_to_jiffies(BQ24257_ILIM_SET_DELAY));
 	} else if (new_state->fault == FAULT_NO_BAT) {
 		dev_warn(bq->dev, "Battery removed\n");
 	} else if (new_state->fault == FAULT_TIMER) {
 		dev_err(bq->dev, "Safety timer expired! Battery dead?\n");
 	}

 	return;

 error:
 	dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
 }

 static irqreturn_t bq24257_irq_handler_thread(int irq, void *private)
 {
 	int ret;
 	struct bq24257_device *bq = private;
 	struct bq24257_state state;

 	ret = bq24257_get_chip_state(bq, &state);
 	if (ret < 0)
 		return IRQ_HANDLED;

 	if (!bq24257_state_changed(bq, &state))
 		return IRQ_HANDLED;

 	dev_dbg(bq->dev, "irq(state changed): status/fault/pg = %d/%d/%d\n",
 		state.status, state.fault, state.power_good);

 	bq24257_handle_state_change(bq, &state);

 	mutex_lock(&bq->lock);
 	bq->state = state;
 	mutex_unlock(&bq->lock);

 	power_supply_changed(bq->charger);

 	return IRQ_HANDLED;
 }

 static int bq24257_hw_init(struct bq24257_device *bq)
 {
 	int ret;
 	int i;
 	struct bq24257_state state;

 	const struct {
 		int field;
 		u32 value;
 	} init_data[] = {
 		{F_ICHG, bq->init_data.ichg},
 		{F_VBAT, bq->init_data.vbat},
 		{F_ITERM, bq->init_data.iterm}
 	};

 	/*
 	 * Disable the watchdog timer to prevent the IC from going back to
 	 * default settings after 50 seconds of I2C inactivity.
 	 */
 	ret = bq24257_field_write(bq, F_WD_EN, 0);
 	if (ret < 0)
 		return ret;

 	/* configure the charge currents and voltages */
 	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
 		ret = bq24257_field_write(bq, init_data[i].field,
 					  init_data[i].value);
 		if (ret < 0)
 			return ret;
 	}

 	ret = bq24257_get_chip_state(bq, &state);
 	if (ret < 0)
 		return ret;

 	mutex_lock(&bq->lock);
 	bq->state = state;
 	mutex_unlock(&bq->lock);

 	if (!state.power_good)
 		/* activate D+/D- detection algorithm */
 		ret = bq24257_field_write(bq, F_DPDM_EN, 1);
 	else if (state.fault != FAULT_NO_BAT)
 		ret = bq24257_iilimit_autoset(bq);

 	return ret;
 }

 static enum power_supply_property bq24257_power_supply_props[] = {
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
 	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
 };

 static char *bq24257_charger_supplied_to[] = {
 	"main-battery",
 };

 static const struct power_supply_desc bq24257_power_supply_desc = {
 	.name = "bq24257-charger",
 	.type = POWER_SUPPLY_TYPE_USB,
 	.properties = bq24257_power_supply_props,
 	.num_properties = ARRAY_SIZE(bq24257_power_supply_props),
 	.get_property = bq24257_power_supply_get_property,
 };

 static int bq24257_power_supply_init(struct bq24257_device *bq)
 {
 	struct power_supply_config psy_cfg = { .drv_data = bq, };

 	psy_cfg.supplied_to = bq24257_charger_supplied_to;
 	psy_cfg.num_supplicants = ARRAY_SIZE(bq24257_charger_supplied_to);

 	bq->charger = devm_power_supply_register(bq->dev,
 						 &bq24257_power_supply_desc,
 						 &psy_cfg);

 	return PTR_ERR_OR_ZERO(bq->charger);
 }

 static int bq24257_pg_gpio_probe(struct bq24257_device *bq)
 {
 	bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN);
 	if (IS_ERR(bq->pg)) {
 		dev_err(bq->dev, "could not probe PG pin\n");
 		return PTR_ERR(bq->pg);
 	}

 	return 0;
 }

 static int bq24257_fw_probe(struct bq24257_device *bq)
 {
 	int ret;
 	u32 property;

 	ret = device_property_read_u32(bq->dev, "ti,charge-current", &property);
 	if (ret < 0)
 		return ret;

 	bq->init_data.ichg = bq24257_find_idx(property, bq24257_ichg_map,
 					      BQ24257_ICHG_MAP_SIZE);

 	ret = device_property_read_u32(bq->dev, "ti,battery-regulation-voltage",
 				       &property);
 	if (ret < 0)
 		return ret;

 	bq->init_data.vbat = bq24257_find_idx(property, bq24257_vbat_map,
 					      BQ24257_VBAT_MAP_SIZE);

 	ret = device_property_read_u32(bq->dev, "ti,termination-current",
 				       &property);
 	if (ret < 0)
 		return ret;

 	bq->init_data.iterm = bq24257_find_idx(property, bq24257_iterm_map,
 					       BQ24257_ITERM_MAP_SIZE);

 	return 0;
 }

 static int bq24257_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 	struct device *dev = &client->dev;
 	struct bq24257_device *bq;
 	int ret;
 	int i;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
 		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
 		return -ENODEV;
 	}

 	bq = devm_kzalloc(dev, sizeof(*bq), GFP_KERNEL);
 	if (!bq)
 		return -ENOMEM;

 	bq->client = client;
 	bq->dev = dev;

 	mutex_init(&bq->lock);

 	bq->rmap = devm_regmap_init_i2c(client, &bq24257_regmap_config);
 	if (IS_ERR(bq->rmap)) {
 		dev_err(dev, "failed to allocate register map\n");
 		return PTR_ERR(bq->rmap);
 	}

 	for (i = 0; i < ARRAY_SIZE(bq24257_reg_fields); i++) {
 		const struct reg_field *reg_fields = bq24257_reg_fields;

 		bq->rmap_fields[i] = devm_regmap_field_alloc(dev, bq->rmap,
 							     reg_fields[i]);
 		if (IS_ERR(bq->rmap_fields[i])) {
 			dev_err(dev, "cannot allocate regmap field\n");
 			return PTR_ERR(bq->rmap_fields[i]);
 		}
 	}

 	i2c_set_clientdata(client, bq);

 	INIT_DELAYED_WORK(&bq->iilimit_setup_work, bq24257_iilimit_setup_work);

 	if (!dev->platform_data) {
 		ret = bq24257_fw_probe(bq);
 		if (ret < 0) {
 			dev_err(dev, "Cannot read device properties.\n");
 			return ret;
 		}
 	} else {
 		return -ENODEV;
 	}

 	/* we can only check Power Good status by probing the PG pin */
 	ret = bq24257_pg_gpio_probe(bq);
 	if (ret < 0)
 		return ret;

 	/* reset all registers to defaults */
 	ret = bq24257_field_write(bq, F_RESET, 1);
 	if (ret < 0)
 		return ret;

 	/*
 	 * Put the RESET bit back to 0, in cache. For some reason the HW always
 	 * returns 1 on this bit, so this is the only way to avoid resetting the
 	 * chip every time we update another field in this register.
 	 */
 	ret = bq24257_field_write(bq, F_RESET, 0);
 	if (ret < 0)
 		return ret;

 	ret = bq24257_hw_init(bq);
 	if (ret < 0) {
 		dev_err(dev, "Cannot initialize the chip.\n");
 		return ret;
 	}

 	ret = devm_request_threaded_irq(dev, client->irq, NULL,
 					bq24257_irq_handler_thread,
 					IRQF_TRIGGER_FALLING |
 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 					"bq24257", bq);
 	if (ret) {
 		dev_err(dev, "Failed to request IRQ #%d\n", client->irq);
 		return ret;
 	}

 	ret = bq24257_power_supply_init(bq);
 	if (ret < 0)
 		dev_err(dev, "Failed to register power supply\n");

 	return ret;
 }

 static int bq24257_remove(struct i2c_client *client)
 {
 	struct bq24257_device *bq = i2c_get_clientdata(client);

 	cancel_delayed_work_sync(&bq->iilimit_setup_work);

 	bq24257_field_write(bq, F_RESET, 1); /* reset to defaults */

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int bq24257_suspend(struct device *dev)
 {
 	struct bq24257_device *bq = dev_get_drvdata(dev);
 	int ret = 0;

 	cancel_delayed_work_sync(&bq->iilimit_setup_work);

 	/* reset all registers to default (and activate standalone mode) */
 	ret = bq24257_field_write(bq, F_RESET, 1);
 	if (ret < 0)
 		dev_err(bq->dev, "Cannot reset chip to standalone mode.\n");

 	return ret;
 }

 static int bq24257_resume(struct device *dev)
 {
 	int ret;
 	struct bq24257_device *bq = dev_get_drvdata(dev);

 	ret = regcache_drop_region(bq->rmap, BQ24257_REG_1, BQ24257_REG_7);
 	if (ret < 0)
 		return ret;

 	ret = bq24257_field_write(bq, F_RESET, 0);
 	if (ret < 0)
 		return ret;

 	ret = bq24257_hw_init(bq);
 	if (ret < 0) {
 		dev_err(bq->dev, "Cannot init chip after resume.\n");
 		return ret;
 	}

 	/* signal userspace, maybe state changed while suspended */
 	power_supply_changed(bq->charger);

 	return 0;
 }
 #endif

 static const struct dev_pm_ops bq24257_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(bq24257_suspend, bq24257_resume)
 };

 static const struct i2c_device_id bq24257_i2c_ids[] = {
 	{ "bq24257", 0 },
 	{},
 };
 MODULE_DEVICE_TABLE(i2c, bq24257_i2c_ids);

 static const struct of_device_id bq24257_of_match[] = {
 	{ .compatible = "ti,bq24257", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, bq24257_of_match);

 static const struct acpi_device_id bq24257_acpi_match[] = {
 	{"BQ242570", 0},
 	{},
 };
 MODULE_DEVICE_TABLE(acpi, bq24257_acpi_match);

 static struct i2c_driver bq24257_driver = {
 	.driver = {
 		.name = "bq24257-charger",
 		.of_match_table = of_match_ptr(bq24257_of_match),
 		.acpi_match_table = ACPI_PTR(bq24257_acpi_match),
 		.pm = &bq24257_pm,
 	},
 	.probe = bq24257_probe,
 	.remove = bq24257_remove,
 	.id_table = bq24257_i2c_ids,
 };
 module_i2c_driver(bq24257_driver);

 MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
 MODULE_DESCRIPTION("bq24257 charger driver");
 MODULE_LICENSE("GPL");
	/*
	* TI BQ24257 charger driver
	*
	* Copyright (C) 2015 Intel Corporation
	*
	* 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.
	*
	*/

	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/power_supply.h>
	#include <linux/regmap.h>
	#include <linux/types.h>
	#include <linux/gpio/consumer.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>

	#include <linux/acpi.h>
	#include <linux/of.h>

	#define BQ24257_REG_1 0x00
	#define BQ24257_REG_2 0x01
	#define BQ24257_REG_3 0x02
	#define BQ24257_REG_4 0x03
	#define BQ24257_REG_5 0x04
	#define BQ24257_REG_6 0x05
	#define BQ24257_REG_7 0x06

	#define BQ24257_MANUFACTURER "Texas Instruments"
	#define BQ24257_PG_GPIO "pg"

	#define BQ24257_ILIM_SET_DELAY 1000 /* msec */

	enum bq24257_fields {
	F_WD_FAULT, F_WD_EN, F_STAT, F_FAULT, /* REG 1 */
	F_RESET, F_IILIMIT, F_EN_STAT, F_EN_TERM, F_CE, F_HZ_MODE, /* REG 2 */
	F_VBAT, F_USB_DET, /* REG 3 */
	F_ICHG, F_ITERM, /* REG 4 */
	F_LOOP_STATUS, F_LOW_CHG, F_DPDM_EN, F_CE_STATUS, F_VINDPM, /* REG 5 */
	F_X2_TMR_EN, F_TMR, F_SYSOFF, F_TS_STAT, /* REG 6 */
	F_VOVP, F_CLR_VDP, F_FORCE_BATDET, F_FORCE_PTM, /* REG 7 */

	F_MAX_FIELDS
	};

	/* initial field values, converted from uV/uA */
	struct bq24257_init_data {
	u8 ichg; /* charge current */
	u8 vbat; /* regulation voltage */
	u8 iterm; /* termination current */
	};

	struct bq24257_state {
	u8 status;
	u8 fault;
	bool power_good;
	};

	struct bq24257_device {
	struct i2c_client *client;
	struct device *dev;
	struct power_supply *charger;

	struct regmap *rmap;
	struct regmap_field *rmap_fields[F_MAX_FIELDS];

	struct gpio_desc *pg;

	struct delayed_work iilimit_setup_work;

	struct bq24257_init_data init_data;
	struct bq24257_state state;

	struct mutex lock; /* protect state data */
	};

	static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg)
	{
	switch (reg) {
	case BQ24257_REG_2:
	case BQ24257_REG_4:
	return false;

	default:
	return true;
	}
	}

	static const struct regmap_config bq24257_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,

	.max_register = BQ24257_REG_7,
	.cache_type = REGCACHE_RBTREE,

	.volatile_reg = bq24257_is_volatile_reg,
	};

	static const struct reg_field bq24257_reg_fields[] = {
	/* REG 1 */
	[F_WD_FAULT] = REG_FIELD(BQ24257_REG_1, 7, 7),
	[F_WD_EN] = REG_FIELD(BQ24257_REG_1, 6, 6),
	[F_STAT] = REG_FIELD(BQ24257_REG_1, 4, 5),
	[F_FAULT] = REG_FIELD(BQ24257_REG_1, 0, 3),
	/* REG 2 */
	[F_RESET] = REG_FIELD(BQ24257_REG_2, 7, 7),
	[F_IILIMIT] = REG_FIELD(BQ24257_REG_2, 4, 6),
	[F_EN_STAT] = REG_FIELD(BQ24257_REG_2, 3, 3),
	[F_EN_TERM] = REG_FIELD(BQ24257_REG_2, 2, 2),
	[F_CE] = REG_FIELD(BQ24257_REG_2, 1, 1),
	[F_HZ_MODE] = REG_FIELD(BQ24257_REG_2, 0, 0),
	/* REG 3 */
	[F_VBAT] = REG_FIELD(BQ24257_REG_3, 2, 7),
	[F_USB_DET] = REG_FIELD(BQ24257_REG_3, 0, 1),
	/* REG 4 */
	[F_ICHG] = REG_FIELD(BQ24257_REG_4, 3, 7),
	[F_ITERM] = REG_FIELD(BQ24257_REG_4, 0, 2),
	/* REG 5 */
	[F_LOOP_STATUS] = REG_FIELD(BQ24257_REG_5, 6, 7),
	[F_LOW_CHG] = REG_FIELD(BQ24257_REG_5, 5, 5),
	[F_DPDM_EN] = REG_FIELD(BQ24257_REG_5, 4, 4),
	[F_CE_STATUS] = REG_FIELD(BQ24257_REG_5, 3, 3),
	[F_VINDPM] = REG_FIELD(BQ24257_REG_5, 0, 2),
	/* REG 6 */
	[F_X2_TMR_EN] = REG_FIELD(BQ24257_REG_6, 7, 7),
	[F_TMR] = REG_FIELD(BQ24257_REG_6, 5, 6),
	[F_SYSOFF] = REG_FIELD(BQ24257_REG_6, 4, 4),
	[F_TS_STAT] = REG_FIELD(BQ24257_REG_6, 0, 2),
	/* REG 7 */
	[F_VOVP] = REG_FIELD(BQ24257_REG_7, 5, 7),
	[F_CLR_VDP] = REG_FIELD(BQ24257_REG_7, 4, 4),
	[F_FORCE_BATDET] = REG_FIELD(BQ24257_REG_7, 3, 3),
	[F_FORCE_PTM] = REG_FIELD(BQ24257_REG_7, 2, 2)
	};

	static const u32 bq24257_vbat_map[] = {
	3500000, 3520000, 3540000, 3560000, 3580000, 3600000, 3620000, 3640000,
	3660000, 3680000, 3700000, 3720000, 3740000, 3760000, 3780000, 3800000,
	3820000, 3840000, 3860000, 3880000, 3900000, 3920000, 3940000, 3960000,
	3980000, 4000000, 4020000, 4040000, 4060000, 4080000, 4100000, 4120000,
	4140000, 4160000, 4180000, 4200000, 4220000, 4240000, 4260000, 4280000,
	4300000, 4320000, 4340000, 4360000, 4380000, 4400000, 4420000, 4440000
	};

	#define BQ24257_VBAT_MAP_SIZE ARRAY_SIZE(bq24257_vbat_map)

	static const u32 bq24257_ichg_map[] = {
	500000, 550000, 600000, 650000, 700000, 750000, 800000, 850000, 900000,
	950000, 1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000,
	1350000, 1400000, 1450000, 1500000, 1550000, 1600000, 1650000, 1700000,
	1750000, 1800000, 1850000, 1900000, 1950000, 2000000
	};

	#define BQ24257_ICHG_MAP_SIZE ARRAY_SIZE(bq24257_ichg_map)

	static const u32 bq24257_iterm_map[] = {
	50000, 75000, 100000, 125000, 150000, 175000, 200000, 225000
	};

	#define BQ24257_ITERM_MAP_SIZE ARRAY_SIZE(bq24257_iterm_map)

	static int bq24257_field_read(struct bq24257_device *bq,
	enum bq24257_fields field_id)
	{
	int ret;
	int val;

	ret = regmap_field_read(bq->rmap_fields[field_id], &val);
	if (ret < 0)
	return ret;

	return val;
	}

	static int bq24257_field_write(struct bq24257_device *bq,
	enum bq24257_fields field_id, u8 val)
	{
	return regmap_field_write(bq->rmap_fields[field_id], val);
	}

	static u8 bq24257_find_idx(u32 value, const u32 *map, u8 map_size)
	{
	u8 idx;

	for (idx = 1; idx < map_size; idx++)
	if (value < map[idx])
	break;

	return idx - 1;
	}

	enum bq24257_status {
	STATUS_READY,
	STATUS_CHARGE_IN_PROGRESS,
	STATUS_CHARGE_DONE,
	STATUS_FAULT,
	};

	enum bq24257_fault {
	FAULT_NORMAL,
	FAULT_INPUT_OVP,
	FAULT_INPUT_UVLO,
	FAULT_SLEEP,
	FAULT_BAT_TS,
	FAULT_BAT_OVP,
	FAULT_TS,
	FAULT_TIMER,
	FAULT_NO_BAT,
	FAULT_ISET,
	FAULT_INPUT_LDO_LOW,
	};

	static int bq24257_power_supply_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct bq24257_device *bq = power_supply_get_drvdata(psy);
	struct bq24257_state state;

	mutex_lock(&bq->lock);
	state = bq->state;
	mutex_unlock(&bq->lock);

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	if (!state.power_good)
	val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
	else if (state.status == STATUS_READY)
	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	else if (state.status == STATUS_CHARGE_IN_PROGRESS)
	val->intval = POWER_SUPPLY_STATUS_CHARGING;
	else if (state.status == STATUS_CHARGE_DONE)
	val->intval = POWER_SUPPLY_STATUS_FULL;
	else
	val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
	break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
	val->strval = BQ24257_MANUFACTURER;
	break;

	case POWER_SUPPLY_PROP_ONLINE:
	val->intval = state.power_good;
	break;

	case POWER_SUPPLY_PROP_HEALTH:
	switch (state.fault) {
	case FAULT_NORMAL:
	val->intval = POWER_SUPPLY_HEALTH_GOOD;
	break;

	case FAULT_INPUT_OVP:
	case FAULT_BAT_OVP:
	val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
	break;

	case FAULT_TS:
	case FAULT_BAT_TS:
	val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
	break;

	case FAULT_TIMER:
	val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
	break;

	default:
	val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
	break;
	}

	break;

	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
	val->intval = bq24257_ichg_map[bq->init_data.ichg];
	break;

	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
	val->intval = bq24257_ichg_map[BQ24257_ICHG_MAP_SIZE - 1];
	break;

	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
	val->intval = bq24257_vbat_map[bq->init_data.vbat];
	break;

	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
	val->intval = bq24257_vbat_map[BQ24257_VBAT_MAP_SIZE - 1];
	break;

	case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
	val->intval = bq24257_iterm_map[bq->init_data.iterm];
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static int bq24257_get_chip_state(struct bq24257_device *bq,
	struct bq24257_state *state)
	{
	int ret;

	ret = bq24257_field_read(bq, F_STAT);
	if (ret < 0)
	return ret;

	state->status = ret;

	ret = bq24257_field_read(bq, F_FAULT);
	if (ret < 0)
	return ret;

	state->fault = ret;

	state->power_good = !gpiod_get_value_cansleep(bq->pg);

	return 0;
	}

	static bool bq24257_state_changed(struct bq24257_device *bq,
	struct bq24257_state *new_state)
	{
	int ret;

	mutex_lock(&bq->lock);
	ret = (bq->state.status != new_state->status \|\|
	bq->state.fault != new_state->fault \|\|
	bq->state.power_good != new_state->power_good);
	mutex_unlock(&bq->lock);

	return ret;
	}

	enum bq24257_loop_status {
	LOOP_STATUS_NONE,
	LOOP_STATUS_IN_DPM,
	LOOP_STATUS_IN_CURRENT_LIMIT,
	LOOP_STATUS_THERMAL,
	};

	enum bq24257_in_ilimit {
	IILIMIT_100,
	IILIMIT_150,
	IILIMIT_500,
	IILIMIT_900,
	IILIMIT_1500,
	IILIMIT_2000,
	IILIMIT_EXT,
	IILIMIT_NONE,
	};

	enum bq24257_port_type {
	PORT_TYPE_DCP, /* Dedicated Charging Port */
	PORT_TYPE_CDP, /* Charging Downstream Port */
	PORT_TYPE_SDP, /* Standard Downstream Port */
	PORT_TYPE_NON_STANDARD,
	};

	enum bq24257_safety_timer {
	SAFETY_TIMER_45,
	SAFETY_TIMER_360,
	SAFETY_TIMER_540,
	SAFETY_TIMER_NONE,
	};

	static int bq24257_iilimit_autoset(struct bq24257_device *bq)
	{
	int loop_status;
	int iilimit;
	int port_type;
	int ret;
	const u8 new_iilimit[] = {
	[PORT_TYPE_DCP] = IILIMIT_2000,
	[PORT_TYPE_CDP] = IILIMIT_2000,
	[PORT_TYPE_SDP] = IILIMIT_500,
	[PORT_TYPE_NON_STANDARD] = IILIMIT_500
	};

	ret = bq24257_field_read(bq, F_LOOP_STATUS);
	if (ret < 0)
	goto error;

	loop_status = ret;

	ret = bq24257_field_read(bq, F_IILIMIT);
	if (ret < 0)
	goto error;

	iilimit = ret;

	/*
	* All USB ports should be able to handle 500mA. If not, DPM will lower
	* the charging current to accommodate the power source. No need to set
	* a lower IILIMIT value.
	*/
	if (loop_status == LOOP_STATUS_IN_DPM && iilimit == IILIMIT_500)
	return 0;

	ret = bq24257_field_read(bq, F_USB_DET);
	if (ret < 0)
	goto error;

	port_type = ret;

	ret = bq24257_field_write(bq, F_IILIMIT, new_iilimit[port_type]);
	if (ret < 0)
	goto error;

	ret = bq24257_field_write(bq, F_TMR, SAFETY_TIMER_360);
	if (ret < 0)
	goto error;

	ret = bq24257_field_write(bq, F_CLR_VDP, 1);
	if (ret < 0)
	goto error;

	dev_dbg(bq->dev, "port/loop = %d/%d -> iilimit = %d\n",
	port_type, loop_status, new_iilimit[port_type]);

	return 0;

	error:
	dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
	return ret;
	}

	static void bq24257_iilimit_setup_work(struct work_struct *work)
	{
	struct bq24257_device *bq = container_of(work, struct bq24257_device,
	iilimit_setup_work.work);

	bq24257_iilimit_autoset(bq);
	}

	static void bq24257_handle_state_change(struct bq24257_device *bq,
	struct bq24257_state *new_state)
	{
	int ret;
	struct bq24257_state old_state;

	mutex_lock(&bq->lock);
	old_state = bq->state;
	mutex_unlock(&bq->lock);

	if (!new_state->power_good) {
	dev_dbg(bq->dev, "Power removed\n");
	cancel_delayed_work_sync(&bq->iilimit_setup_work);

	/* activate D+/D- port detection algorithm */
	ret = bq24257_field_write(bq, F_DPDM_EN, 1);
	if (ret < 0)
	goto error;

	/* reset input current limit */
	ret = bq24257_field_write(bq, F_IILIMIT, IILIMIT_500);
	if (ret < 0)
	goto error;
	} else if (!old_state.power_good) {
	dev_dbg(bq->dev, "Power inserted\n");

	/* configure input current limit */
	schedule_delayed_work(&bq->iilimit_setup_work,
	msecs_to_jiffies(BQ24257_ILIM_SET_DELAY));
	} else if (new_state->fault == FAULT_NO_BAT) {
	dev_warn(bq->dev, "Battery removed\n");
	} else if (new_state->fault == FAULT_TIMER) {
	dev_err(bq->dev, "Safety timer expired! Battery dead?\n");
	}

	return;

	error:
	dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
	}

	static irqreturn_t bq24257_irq_handler_thread(int irq, void *private)
	{
	int ret;
	struct bq24257_device *bq = private;
	struct bq24257_state state;

	ret = bq24257_get_chip_state(bq, &state);
	if (ret < 0)
	return IRQ_HANDLED;

	if (!bq24257_state_changed(bq, &state))
	return IRQ_HANDLED;

	dev_dbg(bq->dev, "irq(state changed): status/fault/pg = %d/%d/%d\n",
	state.status, state.fault, state.power_good);

	bq24257_handle_state_change(bq, &state);

	mutex_lock(&bq->lock);
	bq->state = state;
	mutex_unlock(&bq->lock);

	power_supply_changed(bq->charger);

	return IRQ_HANDLED;
	}

	static int bq24257_hw_init(struct bq24257_device *bq)
	{
	int ret;
	int i;
	struct bq24257_state state;

	const struct {
	int field;
	u32 value;
	} init_data[] = {
	{F_ICHG, bq->init_data.ichg},
	{F_VBAT, bq->init_data.vbat},
	{F_ITERM, bq->init_data.iterm}
	};

	/*
	* Disable the watchdog timer to prevent the IC from going back to
	* default settings after 50 seconds of I2C inactivity.
	*/
	ret = bq24257_field_write(bq, F_WD_EN, 0);
	if (ret < 0)
	return ret;

	/* configure the charge currents and voltages */
	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
	ret = bq24257_field_write(bq, init_data[i].field,
	init_data[i].value);
	if (ret < 0)
	return ret;
	}

	ret = bq24257_get_chip_state(bq, &state);
	if (ret < 0)
	return ret;

	mutex_lock(&bq->lock);
	bq->state = state;
	mutex_unlock(&bq->lock);

	if (!state.power_good)
	/* activate D+/D- detection algorithm */
	ret = bq24257_field_write(bq, F_DPDM_EN, 1);
	else if (state.fault != FAULT_NO_BAT)
	ret = bq24257_iilimit_autoset(bq);

	return ret;
	}

	static enum power_supply_property bq24257_power_supply_props[] = {
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
	POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
	};

	static char *bq24257_charger_supplied_to[] = {
	"main-battery",
	};

	static const struct power_supply_desc bq24257_power_supply_desc = {
	.name = "bq24257-charger",
	.type = POWER_SUPPLY_TYPE_USB,
	.properties = bq24257_power_supply_props,
	.num_properties = ARRAY_SIZE(bq24257_power_supply_props),
	.get_property = bq24257_power_supply_get_property,
	};

	static int bq24257_power_supply_init(struct bq24257_device *bq)
	{
	struct power_supply_config psy_cfg = { .drv_data = bq, };

	psy_cfg.supplied_to = bq24257_charger_supplied_to;
	psy_cfg.num_supplicants = ARRAY_SIZE(bq24257_charger_supplied_to);

	bq->charger = devm_power_supply_register(bq->dev,
	&bq24257_power_supply_desc,
	&psy_cfg);

	return PTR_ERR_OR_ZERO(bq->charger);
	}

	static int bq24257_pg_gpio_probe(struct bq24257_device *bq)
	{
	bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN);
	if (IS_ERR(bq->pg)) {
	dev_err(bq->dev, "could not probe PG pin\n");
	return PTR_ERR(bq->pg);
	}

	return 0;
	}

	static int bq24257_fw_probe(struct bq24257_device *bq)
	{
	int ret;
	u32 property;

	ret = device_property_read_u32(bq->dev, "ti,charge-current", &property);
	if (ret < 0)
	return ret;

	bq->init_data.ichg = bq24257_find_idx(property, bq24257_ichg_map,
	BQ24257_ICHG_MAP_SIZE);

	ret = device_property_read_u32(bq->dev, "ti,battery-regulation-voltage",
	&property);
	if (ret < 0)
	return ret;

	bq->init_data.vbat = bq24257_find_idx(property, bq24257_vbat_map,
	BQ24257_VBAT_MAP_SIZE);

	ret = device_property_read_u32(bq->dev, "ti,termination-current",
	&property);
	if (ret < 0)
	return ret;

	bq->init_data.iterm = bq24257_find_idx(property, bq24257_iterm_map,
	BQ24257_ITERM_MAP_SIZE);

	return 0;
	}

	static int bq24257_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct device *dev = &client->dev;
	struct bq24257_device *bq;
	int ret;
	int i;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
	dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
	return -ENODEV;
	}

	bq = devm_kzalloc(dev, sizeof(*bq), GFP_KERNEL);
	if (!bq)
	return -ENOMEM;

	bq->client = client;
	bq->dev = dev;

	mutex_init(&bq->lock);

	bq->rmap = devm_regmap_init_i2c(client, &bq24257_regmap_config);
	if (IS_ERR(bq->rmap)) {
	dev_err(dev, "failed to allocate register map\n");
	return PTR_ERR(bq->rmap);
	}

	for (i = 0; i < ARRAY_SIZE(bq24257_reg_fields); i++) {
	const struct reg_field *reg_fields = bq24257_reg_fields;

	bq->rmap_fields[i] = devm_regmap_field_alloc(dev, bq->rmap,
	reg_fields[i]);
	if (IS_ERR(bq->rmap_fields[i])) {
	dev_err(dev, "cannot allocate regmap field\n");
	return PTR_ERR(bq->rmap_fields[i]);
	}
	}

	i2c_set_clientdata(client, bq);

	INIT_DELAYED_WORK(&bq->iilimit_setup_work, bq24257_iilimit_setup_work);

	if (!dev->platform_data) {
	ret = bq24257_fw_probe(bq);
	if (ret < 0) {
	dev_err(dev, "Cannot read device properties.\n");
	return ret;
	}
	} else {
	return -ENODEV;
	}

	/* we can only check Power Good status by probing the PG pin */
	ret = bq24257_pg_gpio_probe(bq);
	if (ret < 0)
	return ret;

	/* reset all registers to defaults */
	ret = bq24257_field_write(bq, F_RESET, 1);
	if (ret < 0)
	return ret;

	/*
	* Put the RESET bit back to 0, in cache. For some reason the HW always
	* returns 1 on this bit, so this is the only way to avoid resetting the
	* chip every time we update another field in this register.
	*/
	ret = bq24257_field_write(bq, F_RESET, 0);
	if (ret < 0)
	return ret;

	ret = bq24257_hw_init(bq);
	if (ret < 0) {
	dev_err(dev, "Cannot initialize the chip.\n");
	return ret;
	}

	ret = devm_request_threaded_irq(dev, client->irq, NULL,
	bq24257_irq_handler_thread,
	IRQF_TRIGGER_FALLING \|
	IRQF_TRIGGER_RISING \| IRQF_ONESHOT,
	"bq24257", bq);
	if (ret) {
	dev_err(dev, "Failed to request IRQ #%d\n", client->irq);
	return ret;
	}

	ret = bq24257_power_supply_init(bq);
	if (ret < 0)
	dev_err(dev, "Failed to register power supply\n");

	return ret;
	}

	static int bq24257_remove(struct i2c_client *client)
	{
	struct bq24257_device *bq = i2c_get_clientdata(client);

	cancel_delayed_work_sync(&bq->iilimit_setup_work);

	bq24257_field_write(bq, F_RESET, 1); /* reset to defaults */

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int bq24257_suspend(struct device *dev)
	{
	struct bq24257_device *bq = dev_get_drvdata(dev);
	int ret = 0;

	cancel_delayed_work_sync(&bq->iilimit_setup_work);

	/* reset all registers to default (and activate standalone mode) */
	ret = bq24257_field_write(bq, F_RESET, 1);
	if (ret < 0)
	dev_err(bq->dev, "Cannot reset chip to standalone mode.\n");

	return ret;
	}

	static int bq24257_resume(struct device *dev)
	{
	int ret;
	struct bq24257_device *bq = dev_get_drvdata(dev);

	ret = regcache_drop_region(bq->rmap, BQ24257_REG_1, BQ24257_REG_7);
	if (ret < 0)
	return ret;

	ret = bq24257_field_write(bq, F_RESET, 0);
	if (ret < 0)
	return ret;

	ret = bq24257_hw_init(bq);
	if (ret < 0) {
	dev_err(bq->dev, "Cannot init chip after resume.\n");
	return ret;
	}

	/* signal userspace, maybe state changed while suspended */
	power_supply_changed(bq->charger);

	return 0;
	}
	#endif

	static const struct dev_pm_ops bq24257_pm = {
	SET_SYSTEM_SLEEP_PM_OPS(bq24257_suspend, bq24257_resume)
	};

	static const struct i2c_device_id bq24257_i2c_ids[] = {
	{ "bq24257", 0 },
	{},
	};
	MODULE_DEVICE_TABLE(i2c, bq24257_i2c_ids);

	static const struct of_device_id bq24257_of_match[] = {
	{ .compatible = "ti,bq24257", },
	{ },
	};
	MODULE_DEVICE_TABLE(of, bq24257_of_match);

	static const struct acpi_device_id bq24257_acpi_match[] = {
	{"BQ242570", 0},
	{},
	};
	MODULE_DEVICE_TABLE(acpi, bq24257_acpi_match);

	static struct i2c_driver bq24257_driver = {
	.driver = {
	.name = "bq24257-charger",
	.of_match_table = of_match_ptr(bq24257_of_match),
	.acpi_match_table = ACPI_PTR(bq24257_acpi_match),
	.pm = &bq24257_pm,
	},
	.probe = bq24257_probe,
	.remove = bq24257_remove,
	.id_table = bq24257_i2c_ids,
	};
	module_i2c_driver(bq24257_driver);

	MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
	MODULE_DESCRIPTION("bq24257 charger driver");
	MODULE_LICENSE("GPL");