drivers/power/bq24251_charger.c

/*
 * Copyright (C) 2014 Nest Labs
 *
 * 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.
 */

#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/power_supply.h>
#include <linux/printk.h>

#define DCP_CURRENT_LIMIT	1500

#define REG1_READ_COUNT_MAX	10	/* Max loops reading reg1 */

#define REG1_ADDR				0x00

#define REG1_WD_EN				0x40

#define REG1_STATUS_MASK			0x30
#define REG1_STATUS_READY			0x00
#define REG1_STATUS_CHARGE_IN_PROGRESS		0x10
#define REG1_STATUS_CHARGE_DONE			0x20
#define REG1_STATUS_FAULT			0x30

#define REG1_FAULT_MASK				0x0f
#define REG1_FAULT_NORMAL			0x00
#define	REG1_FAULT_INPUT_OVP			0x01
#define REG1_FAULT_INPUT_UVLO			0x02
#define REG1_FAULT_SLEEP			0x03
#define REG1_FAULT_BATTERY_TEMPERATURE_FAULT	0x04
#define REG1_FAULT_BATTERY_OVP			0x05
#define REG1_FAULT_THERMAL_SHUTDOWN		0x06
#define REG1_FAULT_TIMER_FAULT			0x07
#define REG1_FAULT_NO_BATTERY_CONNECTED		0x08
#define REG1_FAULT_ISET_SHORT			0x09
#define REG1_FAULT_INPUT_FAULT_AND_LDO_LOW	0x0a

#define REG2_ADDR                               0x01

#define REG2_RESET_MASK				0x80
#define REG2_IIN_LIMIT_MASK                     0x70
#define REG2_IIN_LIMIT_100                      0x00
#define REG2_IIN_LIMIT_150                      0x10
#define REG2_IIN_LIMIT_500                      0x20
#define REG2_IIN_LIMIT_900                      0x30
#define REG2_IIN_LIMIT_1500                     0x40
#define REG2_IIN_LIMIT_2000                     0x50
#define REG2_IIN_LIMIT_EXT                      0x60
#define REG2_CE_MASK				0x02


#define REG3_ADDR				0x02

#define REG3_VBATREG_MASK			0xfc
#define REG3_VBATREG_MIN			3500000
#define REG3_VBATREG_MAX			4440000
#define REG3_VBATREG_STEP			20000
#define REG3_VBATREG_SHIFT			2

#define REG3_USB_DET_MASK			0x03
#define REG3_USB_DET_DCD			0x00
#define REG3_USB_DET_CDP			0x01
#define REG3_USB_DET_SDP			0x02
#define REG3_USB_DET_NON_STANDARD		0x03


#define REG4_ADDR				0x03

#define REG4_ICHG_MASK				0xf8
#define REG4_ICHG_MIN				500000
#define REG4_ICHG_MAX				2000000
#define REG4_ICHG_STEP				50000
#define REG4_ICHG_SHIFT				3

#define REG4_ITERM_MASK				0x07
#define REG4_ITERM_MIN				50000
#define REG4_ITERM_MAX				225000
#define REG4_ITERM_STEP				25000
#define REG4_ITERM_SHIFT			0


#define REG5_ADDR				0x04

#define REG5_LOW_CHG				0x20

#define REG5_VINDPM_MASK			0x07
#define REG5_VINDPM_MIN				4200000
#define REG5_VINDPM_MAX				4760000
#define REG5_VINDPM_STEP			80000
#define REG5_VINDPM_SHIFT			0


#define REG6_ADDR				0x05

#define REG6_SYSOFF_MASK			0x10


#define REG7_ADDR				0x06

#define REG7_VOVP_MASK				0xe0
#define REG7_VOVP_VAL0				6000000
#define REG7_VOVP_VAL1				6500000
#define REG7_VOVP_VAL2				7000000
#define REG7_VOVP_VAL3				8000000
#define REG7_VOVP_VAL4				9000000
#define REG7_VOVP_VAL5				9500000
#define REG7_VOVP_VAL6				10000000
#define REG7_VOVP_VAL7				10500000
#define REG7_VOVP_SHIFT				5


#define APPLY_LINEAR_CONFIG(client, string, reg, field) \
		bq24251_apply_linear_config( \
			client, \
			string, \
			reg##_ADDR, \
			reg##_##field##_MASK, \
			reg##_##field##_MIN, \
			reg##_##field##_MAX, \
			reg##_##field##_STEP, \
			reg##_##field##_SHIFT)


struct bq24251_device {
	struct mutex thread_mutex;
	struct power_supply bat_ps;
	struct i2c_client *client;
	int stat_gpio;
	int status;
	int health;
	struct iio_channel *chan;
	unsigned int r1_ohm;
	unsigned int r2_ohm;
};

static enum power_supply_property bq24251_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_VOLTAGE_NOW, /* Keep this one last */
};

static const int vovp_vals[] = {
	REG7_VOVP_VAL0,
	REG7_VOVP_VAL1,
	REG7_VOVP_VAL2,
	REG7_VOVP_VAL3,
	REG7_VOVP_VAL4,
	REG7_VOVP_VAL5,
	REG7_VOVP_VAL6,
	REG7_VOVP_VAL7,
};

static int force_input_limit = 0;
module_param(force_input_limit, int, 0444);
MODULE_PARM_DESC(force_input_limit, "Force 2 A input current limit");

static ssize_t bq24251_sysoff_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	unsigned long sysoff;
	int reg6_value;

	reg6_value = i2c_smbus_read_byte_data(client, REG6_ADDR);
	if (reg6_value < 0) {
		dev_err(dev, "Couldn't read Register 6\n");
		return -EIO;
	}

	sysoff = (reg6_value & REG6_SYSOFF_MASK) ? 1 : 0;

	return sprintf(buf, "%lu\n", sysoff);
}

static ssize_t bq24251_sysoff_store(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf, size_t count)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct bq24251_device *bq = i2c_get_clientdata(client);
	unsigned long sysoff;
	int reg6_value;
	int ret;

	ret = strict_strtoul(buf, 10, &sysoff);

	if (ret)
		return ret;

	mutex_lock(&bq->thread_mutex);

	reg6_value = i2c_smbus_read_byte_data(client, REG6_ADDR);

	if (reg6_value < 0) {
		dev_err(dev, "Couldn't read Register 6\n");
		ret = reg6_value;
	} else {
		if (sysoff)
			reg6_value |= REG6_SYSOFF_MASK;
		else
			reg6_value &= ~REG6_SYSOFF_MASK;

		ret = i2c_smbus_write_byte_data(client, REG6_ADDR, reg6_value);
		if (ret == 0)
			ret = count;
	}

	mutex_unlock(&bq->thread_mutex);

	return ret;
}

static ssize_t bq24251_ce_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	unsigned long ce;
	int reg2_value;

	reg2_value = i2c_smbus_read_byte_data(client, REG2_ADDR);
	if (reg2_value < 0) {
		dev_err(dev, "Couldn't read Register 2\n");
		return -EIO;
	}

	ce = (reg2_value & REG2_CE_MASK) ? 0 : 1;

	return sprintf(buf, "%lu\n", ce);
}

static ssize_t bq24251_ce_store(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct bq24251_device *bq = i2c_get_clientdata(client);
	unsigned long ce;
	int reg2_value;
	int ret;

	ret = strict_strtoul(buf, 10, &ce);

	if (ret)
		return ret;

	mutex_lock(&bq->thread_mutex);

	reg2_value = i2c_smbus_read_byte_data(client, REG2_ADDR);

	if (reg2_value < 0) {
		dev_err(dev, "Couldn't read Register 2\n");
		ret = reg2_value;
	} else {
		/* Clear out the reset bit */
		reg2_value &= ~REG2_RESET_MASK;

		if (ce)
			reg2_value &= ~REG2_CE_MASK;
		else
			reg2_value |= REG2_CE_MASK;

		ret = i2c_smbus_write_byte_data(client, REG2_ADDR, reg2_value);
		if (ret == 0)
			ret = count;
	}

	mutex_unlock(&bq->thread_mutex);

	return ret;
}



static int bq24251_bat_get_property(struct power_supply *bat_ps,
				enum power_supply_property prop,
				union power_supply_propval *val)
{
	struct bq24251_device *bq = container_of(bat_ps, struct bq24251_device, bat_ps);
	int ret = 0;

	switch (prop) {

	case POWER_SUPPLY_PROP_STATUS:
		val->intval = bq->status;
		break;

	case POWER_SUPPLY_PROP_HEALTH:
		val->intval = bq->health;
		break;

	case POWER_SUPPLY_PROP_PRESENT:
		/* Always present */
		val->intval = 1;
		break;

	case POWER_SUPPLY_PROP_ONLINE:
		/* Always online */
		val->intval = 1;
		break;

	case POWER_SUPPLY_PROP_TECHNOLOGY:
		/* Only support for Lithium Ion */
		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
		break;

	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		BUG_ON(!bq->chan);

		mutex_lock(&bq->thread_mutex);

		if (ret >= 0) {
			/* Read ADC voltage and compensate for the divider */
			ret = iio_read_channel_processed(bq->chan, &val->intval);
			val->intval *= bq->r1_ohm + bq->r2_ohm;
			val->intval /= bq->r2_ohm;

			/* Processed IIO returns mV but power supply returns uV */
			val->intval *= 1000;
		}

		mutex_unlock(&bq->thread_mutex);

		break;

	case POWER_SUPPLY_PROP_MODEL_NAME:
		val->strval = "bq24251";
		break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
		val->strval = "TI";
		break;

	default:
		ret = -EINVAL;
	}

	return ret;
}

static int bq24251_update_status(struct bq24251_device *bq)
{
	int reg1_value;
	int reg1_read_count = 0;

	/* Read Register 1 until fault bits match status bits */
	do {
		reg1_value = i2c_smbus_read_byte_data(bq->client, REG1_ADDR);
		if (reg1_value < 0) {
			dev_err(&bq->client->dev, "Couldn't read Register 1\n");
			return reg1_value;
		}

		dev_dbg(&bq->client->dev, "Register 1: 0x%02X\n", reg1_value);
		reg1_read_count++;

	} while ((reg1_value & REG1_STATUS_MASK) != REG1_STATUS_FAULT &&
		 (reg1_value & REG1_FAULT_MASK) != REG1_FAULT_NORMAL &&
		 reg1_read_count < REG1_READ_COUNT_MAX);

	/* Set Battery Status */
	switch (reg1_value & REG1_STATUS_MASK) {

	case REG1_STATUS_READY:
		bq->status = POWER_SUPPLY_STATUS_DISCHARGING;
		break;

	case REG1_STATUS_CHARGE_IN_PROGRESS:
		bq->status = POWER_SUPPLY_STATUS_CHARGING;
		break;

	case REG1_STATUS_CHARGE_DONE:
		bq->status = POWER_SUPPLY_STATUS_FULL;
		break;

	default:
		bq->status = POWER_SUPPLY_STATUS_DISCHARGING;
		break;
	}

	/* Set Battery Health */
	switch (reg1_value & REG1_FAULT_MASK) {

	case REG1_FAULT_NORMAL:
	case REG1_FAULT_INPUT_UVLO:
	case REG1_FAULT_INPUT_FAULT_AND_LDO_LOW:
		bq->health = POWER_SUPPLY_HEALTH_GOOD;
		break;

	case REG1_FAULT_INPUT_OVP:
	case REG1_FAULT_BATTERY_OVP:
		bq->health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
		break;

	case REG1_FAULT_BATTERY_TEMPERATURE_FAULT:
	case REG1_FAULT_THERMAL_SHUTDOWN:
		bq->health = POWER_SUPPLY_HEALTH_OVERHEAT;
		break;

	default:
		bq->health = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
		break;
	}

	return 0;
}

static irqreturn_t bq24251_irq_handler(int irq, void *devid)
{
	struct i2c_client *client = devid;
	struct bq24251_device *bq = i2c_get_clientdata(client);

	mutex_lock(&bq->thread_mutex);
	bq24251_update_status(bq);
	mutex_unlock(&bq->thread_mutex);

	pm_wakeup_event(&client->dev, 0);

	power_supply_changed(&bq->bat_ps);

	return IRQ_HANDLED;
}

static int bq24251_apply_linear_config(struct i2c_client *client,
				       const char *string,
				       unsigned int reg,
				       unsigned int mask,
				       unsigned int min,
				       unsigned int max,
				       unsigned int step,
				       unsigned int shift)
{
	struct device_node *np = client->dev.of_node;
	unsigned int prop;
	int reg_value;
	int ret;

	ret = of_property_read_u32(np, string, &prop);
	if (ret == 0) {
		if ((prop < min) | (prop > max)) {
			dev_err(&client->dev, "Invalid %s property\n", string);
			return -EINVAL;
		}

		reg_value = i2c_smbus_read_byte_data(client, reg);
		if (reg_value < 0)
			return reg_value;

		reg_value &= ~mask;
		reg_value |= (((prop - min) / step) << shift) & mask;

		ret = i2c_smbus_write_byte_data(client, reg, reg_value);
		return ret;
	}

	return 0;
}

static int bq24251_parse_configuration(struct i2c_client *client)
{
	struct device_node *np = client->dev.of_node;
	unsigned int prop;
	int reg_value;
	int ret;
	int i;

	/* Disable watchdog so software written parameters take effect */
	reg_value = i2c_smbus_read_byte_data(client, REG1_ADDR);
	if (reg_value < 0)
		return reg_value;

	reg_value &= ~REG1_WD_EN;

	ret = i2c_smbus_write_byte_data(client, REG1_ADDR, reg_value);


	ret = APPLY_LINEAR_CONFIG(client, "battery-regulation-voltage", REG3, VBATREG);
	if (ret)
		return ret;

	ret = APPLY_LINEAR_CONFIG(client, "term-current-sense-threshold", REG4, ITERM);
	if (ret)
		return ret;

	ret = APPLY_LINEAR_CONFIG(client, "charge-current", REG4, ICHG);
	if (ret)
		return ret;

	ret = APPLY_LINEAR_CONFIG(client, "vindpm-threshold", REG5, VINDPM);
	if (ret)
		return ret;

	ret = of_property_read_u32(np, "ovp-voltage", &prop);
	if (ret == 0) {
		for (i = 0; i < ARRAY_SIZE(vovp_vals); i++)
			if (prop == vovp_vals[i]) {
				reg_value = i2c_smbus_read_byte_data(client, REG7_ADDR);
				if (reg_value < 0)
					return reg_value;

				reg_value &= ~REG7_VOVP_MASK;
				reg_value |= i << REG7_VOVP_SHIFT;

				ret = i2c_smbus_write_byte_data(client, REG7_ADDR, reg_value);

				return ret;
			}

		dev_err(&client->dev, "Invalid ovp-voltage property\n");
		return -EINVAL;
	}

	return 0;
}


static int bq24251_bat_get_ext_psy_data(struct device *dev, void *data)
{
	struct power_supply *ext_ps = dev_get_drvdata(dev);
	struct bq24251_device *bq = (struct bq24251_device *) data;
	union power_supply_propval val;
	int i, found = 0;
	int reg2_value;
	int ret;

	/* See if bq->bat_ps is a supplicant of ext_ps */
	if (!ext_ps->name)
		return 0;

	for (i = 0; i < bq->bat_ps.num_supplies; i++)
		if (!strcmp(ext_ps->name, bq->bat_ps.supplied_from[i]))
			found = 1;

	if (!found)
		return 0;

	/* Get the latest max current property */
	if (ext_ps->get_property(ext_ps, POWER_SUPPLY_PROP_CURRENT_MAX, &val))
		return 0;

	dev_info(&bq->client->dev, "Supply limits current to %d mA\n", val.intval);

	mutex_lock(&bq->thread_mutex);

	/* Read Register 2 */
	reg2_value = i2c_smbus_read_byte_data(bq->client, REG2_ADDR);
	if (reg2_value < 0) {
		dev_err(&bq->client->dev, "Couldn't read Register 2\n");
		mutex_unlock(&bq->thread_mutex);
		return reg2_value;
	}

	/* Apply current limit based on what type of charger */
	reg2_value &= ~(REG2_RESET_MASK | REG2_IIN_LIMIT_MASK);

#ifdef CONFIG_CHARGER_BQ24251_FORCE_2A
	reg2_value |= REG2_IIN_LIMIT_2000;
#else
	if (val.intval == DCP_CURRENT_LIMIT || force_input_limit)
		reg2_value |= REG2_IIN_LIMIT_2000; /* Our DCP charger will supply 2A */
	else
		reg2_value |= REG2_IIN_LIMIT_500; /* Otherwise use post-enumeration SDP limit */
#endif

	ret = i2c_smbus_write_byte_data(bq->client, REG2_ADDR, reg2_value);
	if (ret < 0)
		dev_err(&bq->client->dev, "Couldn't write Register 2\n");

	mutex_unlock(&bq->thread_mutex);

	return ret;
}

static void bq24251_bat_ext_changed(struct power_supply *bat_ps)
{
	struct bq24251_device *bq = container_of(bat_ps, struct bq24251_device, bat_ps);

	class_for_each_device(power_supply_class, NULL, bq, bq24251_bat_get_ext_psy_data);
}


static struct device_attribute bq24251_sysoff_attr = {
	.attr = {
		 .name = "sysoff",
		 .mode = S_IRUSR | S_IWUSR,
		 },
	.show = bq24251_sysoff_show,
	.store = bq24251_sysoff_store,
};

static struct device_attribute bq24251_ce_attr = {
	.attr = {
		 .name = "charging_enabled",
		 .mode = S_IRUSR | S_IWUSR,
		 },
	.show = bq24251_ce_show,
	.store = bq24251_ce_store,
};

#ifdef CONFIG_CHARGER_BQ24251_POWER_OFF
struct device *power_off_dev;

static void bq24251_power_off(void)
{
	bq24251_sysoff_store(power_off_dev, NULL, "1", 1);

	mdelay(100);

	bq24251_sysoff_store(power_off_dev, NULL, "0", 1);
}
#endif

static int bq24251_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct bq24251_device *bq;
	struct device_node *np;
	int ret;

	/* Check for OF node */
	np = client->dev.of_node;
	if (!np) {
		dev_err(&client->dev, "Missing DT node\n");
		return -ENODEV;
	}

	/* Claim memory */
	bq = devm_kzalloc(&client->dev, sizeof(*bq), GFP_KERNEL);
	if (!bq)
		return -ENOMEM;

	i2c_set_clientdata(client, bq);
	bq->client = client;

	/* Parse configuration constraints */
	ret = bq24251_parse_configuration(client);
	if (ret)
		return ret;

	bq->bat_ps.name = "bq24251-battery";
	bq->bat_ps.type = POWER_SUPPLY_TYPE_BATTERY;
	bq->bat_ps.get_property = bq24251_bat_get_property;
	bq->bat_ps.properties = bq24251_bat_props;
	bq->bat_ps.num_properties = ARRAY_SIZE(bq24251_bat_props);
	bq->bat_ps.external_power_changed = bq24251_bat_ext_changed;
	bq->bat_ps.of_node = client->dev.of_node;

	mutex_init(&bq->thread_mutex);

	device_init_wakeup(&client->dev, 1);

	/* Get STAT gpio and interrupt */
	bq->stat_gpio = of_get_named_gpio(np, "stat-gpio", 0);
	if (!gpio_is_valid(bq->stat_gpio)) {
		dev_err(&client->dev, "DT missing STAT gpio property\n");
		return -ENODEV;
	}

	ret = devm_gpio_request(&client->dev, bq->stat_gpio, "bq24251-stat");
	if (ret) {
		dev_err(&client->dev, "Couldn't request STAT gpio\n");
		return ret;
	}

	ret = gpio_direction_input(bq->stat_gpio);
	if (ret) {
		dev_err(&client->dev, "Couldn't set STAT gpio direction\n");
		return ret;
	}

	mutex_lock(&bq->thread_mutex);

	ret = devm_request_threaded_irq(&client->dev,
					gpio_to_irq(bq->stat_gpio), NULL,
					bq24251_irq_handler,
					IRQF_ONESHOT | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
					"bq24251-stat", client);
	if (ret) {
		dev_err(&client->dev, "Couldn't request irq for STAT gpio\n");
		goto probe_err_mutex_unlock;
	}

	/* Get optional ADC and voltage divider resistor values */
	bq->chan = iio_channel_get(&client->dev, NULL);
	if (!IS_ERR(bq->chan)) {
		ret = of_property_read_u32(np, "divider-r1-ohm", &bq->r1_ohm);
		if (ret) {
			dev_err(&client->dev, "Couldn't get r1 property from DT\n");
			goto probe_err_iio_release;
		}

		ret = of_property_read_u32(np, "divider-r2-ohm", &bq->r2_ohm);
		if (ret) {
			dev_err(&client->dev, "Couldn't get r2 property from DT\n");
			goto probe_err_iio_release;
		}

		if (!bq->r1_ohm || !bq->r2_ohm) {
			dev_err(&client->dev, "Divider values must be non-zero\n");
			ret = -EINVAL;
			goto probe_err_iio_release;
		}

	} else if (PTR_ERR(bq->chan) == -EPROBE_DEFER) {
		/* If ADC is specified but not available, defer */
		return -EPROBE_DEFER;

	} else {
		dev_info(&client->dev, "No associated ADC\n");

		/* Omit support for POWER_SUPPLY_PROP_VOLTAGE_NOW if no ADC */
		bq->bat_ps.num_properties--;
		bq->chan = 0;
	}

	/* Add sysfs files */
	ret = device_create_file(&client->dev, &bq24251_sysoff_attr);
	if (ret) {
		dev_err(&client->dev, "Failed to create sysoff sysfs file\n");
		goto probe_err_mutex_unlock;
	}

	ret = device_create_file(&client->dev, &bq24251_ce_attr);
	if (ret) {
		dev_err(&client->dev, "Failed to create ce sysfs file\n");
		goto probe_err_sysfs_destroy;
	}

	bq24251_update_status(bq);
	mutex_unlock(&bq->thread_mutex);

	/* Register as power supply */
	power_supply_register(&client->dev, &bq->bat_ps);

	/* Simulate external PS change to set input current */
	bq24251_bat_ext_changed(&bq->bat_ps);

	/* Allow the device to wake us up */
	device_init_wakeup(&client->dev, 1);

#ifdef CONFIG_CHARGER_BQ24251_POWER_OFF
	/* Register a power off hook */
	if (pm_power_off != bq24251_power_off) {
		power_off_dev = &client->dev;
		pm_power_off = bq24251_power_off;
	}
#endif

	return 0;

probe_err_sysfs_destroy:
	device_remove_file(&client->dev, &bq24251_sysoff_attr);

probe_err_mutex_unlock:
	mutex_unlock(&bq->thread_mutex);

probe_err_iio_release:
	iio_channel_release(bq->chan);
	return ret;
}


static int bq24251_remove(struct i2c_client *client)
{
	struct bq24251_device *bq = i2c_get_clientdata(client);

	device_remove_file(&client->dev, &bq24251_ce_attr);

	device_remove_file(&client->dev, &bq24251_sysoff_attr);

	power_supply_unregister(&bq->bat_ps);

	if (bq->chan)
		iio_channel_release(bq->chan);

	device_init_wakeup(&client->dev, 0);

	return 0;
}

static int bq24251_suspend(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct bq24251_device *bq = i2c_get_clientdata(client);

	if (device_may_wakeup(&client->dev))
		enable_irq_wake(gpio_to_irq(bq->stat_gpio));

	return 0;
}

static int bq24251_resume(struct device *dev)
{
	struct i2c_client *client = container_of(dev, struct i2c_client, dev);
	struct bq24251_device *bq = i2c_get_clientdata(client);

	if (device_may_wakeup(&client->dev))
		disable_irq_wake(gpio_to_irq(bq->stat_gpio));

	return 0;
}

static const struct i2c_device_id bq24251_id[] = {
	{ "bq24251-charger", 0 },
	{ }
};

static const struct of_device_id bq24251_match[] = {
	{ .compatible = "ti,bq24251-charger", },
	{ },
};

static SIMPLE_DEV_PM_OPS(bq24251_pm_ops, bq24251_suspend, bq24251_resume);

static struct i2c_driver bq24251_driver = {
	.probe = bq24251_probe,
	.remove = bq24251_remove,
	.id_table = bq24251_id,
	.driver = {
		.name = "bq24251-charger",
		.of_match_table = bq24251_match,
		.pm = &bq24251_pm_ops,
	},
};
module_i2c_driver(bq24251_driver);

MODULE_AUTHOR("Tim Kryger <tkryger@nestlabs.com>");
MODULE_DESCRIPTION("bq24251 charger driver");
MODULE_LICENSE("GPL v2");