drivers/power/supply/bq24735-charger.c - linux - Git at Google

 /*
  * Battery charger driver for TI BQ24735
  *
  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
  *
  * 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;
  *
  * 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.
  *
  * 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.,
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */

 #include <linux/devm-helpers.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/gpio/consumer.h>
 #include <linux/power_supply.h>
 #include <linux/slab.h>

 #include <linux/power/bq24735-charger.h>

 /* BQ24735 available commands and their respective masks */
 #define BQ24735_CHARGE_OPT		0x12
 #define BQ24735_CHARGE_CURRENT		0x14
 #define BQ24735_CHARGE_CURRENT_MASK	0x1fc0
 #define BQ24735_CHARGE_VOLTAGE		0x15
 #define BQ24735_CHARGE_VOLTAGE_MASK	0x7ff0
 #define BQ24735_INPUT_CURRENT		0x3f
 #define BQ24735_INPUT_CURRENT_MASK	0x1f80
 #define BQ24735_MANUFACTURER_ID		0xfe
 #define BQ24735_DEVICE_ID		0xff

 /* ChargeOptions bits of interest */
 #define BQ24735_CHARGE_OPT_CHG_DISABLE	(1 << 0)
 #define BQ24735_CHARGE_OPT_AC_PRESENT	(1 << 4)

 struct bq24735 {
 	struct power_supply		*charger;
 	struct power_supply_desc	charger_desc;
 	struct i2c_client		*client;
 	struct bq24735_platform		*pdata;
 	struct mutex			lock;
 	struct gpio_desc		*status_gpio;
 	struct delayed_work		poll;
 	u32				poll_interval;
 	bool				charging;
 };

 static inline struct bq24735 *to_bq24735(struct power_supply *psy)
 {
 	return power_supply_get_drvdata(psy);
 }

 static enum power_supply_property bq24735_charger_properties[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_ONLINE,
 };

 static int bq24735_charger_property_is_writeable(struct power_supply *psy,
 						 enum power_supply_property psp)
 {
 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		return 1;
 	default:
 		break;
 	}

 	return 0;
 }

 static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
 				     u16 value)
 {
 	return i2c_smbus_write_word_data(client, reg, value);
 }

 static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
 {
 	return i2c_smbus_read_word_data(client, reg);
 }

 static int bq24735_update_word(struct i2c_client *client, u8 reg,
 			       u16 mask, u16 value)
 {
 	unsigned int tmp;
 	int ret;

 	ret = bq24735_read_word(client, reg);
 	if (ret < 0)
 		return ret;

 	tmp = ret & ~mask;
 	tmp |= value & mask;

 	return bq24735_write_word(client, reg, tmp);
 }

 static int bq24735_config_charger(struct bq24735 *charger)
 {
 	struct bq24735_platform *pdata = charger->pdata;
 	int ret;
 	u16 value;

 	if (pdata->ext_control)
 		return 0;

 	if (pdata->charge_current) {
 		value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;

 		ret = bq24735_write_word(charger->client,
 					 BQ24735_CHARGE_CURRENT, value);
 		if (ret < 0) {
 			dev_err(&charger->client->dev,
 				"Failed to write charger current : %d\n",
 				ret);
 			return ret;
 		}
 	}

 	if (pdata->charge_voltage) {
 		value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;

 		ret = bq24735_write_word(charger->client,
 					 BQ24735_CHARGE_VOLTAGE, value);
 		if (ret < 0) {
 			dev_err(&charger->client->dev,
 				"Failed to write charger voltage : %d\n",
 				ret);
 			return ret;
 		}
 	}

 	if (pdata->input_current) {
 		value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;

 		ret = bq24735_write_word(charger->client,
 					 BQ24735_INPUT_CURRENT, value);
 		if (ret < 0) {
 			dev_err(&charger->client->dev,
 				"Failed to write input current : %d\n",
 				ret);
 			return ret;
 		}
 	}

 	return 0;
 }

 static inline int bq24735_enable_charging(struct bq24735 *charger)
 {
 	int ret;

 	if (charger->pdata->ext_control)
 		return 0;

 	ret = bq24735_config_charger(charger);
 	if (ret)
 		return ret;

 	return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
 				   BQ24735_CHARGE_OPT_CHG_DISABLE, 0);
 }

 static inline int bq24735_disable_charging(struct bq24735 *charger)
 {
 	if (charger->pdata->ext_control)
 		return 0;

 	return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
 				   BQ24735_CHARGE_OPT_CHG_DISABLE,
 				   BQ24735_CHARGE_OPT_CHG_DISABLE);
 }

 static bool bq24735_charger_is_present(struct bq24735 *charger)
 {
 	if (charger->status_gpio) {
 		return !gpiod_get_value_cansleep(charger->status_gpio);
 	} else {
 		int ac = 0;

 		ac = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
 		if (ac < 0) {
 			dev_dbg(&charger->client->dev,
 				"Failed to read charger options : %d\n",
 				ac);
 			return false;
 		}
 		return (ac & BQ24735_CHARGE_OPT_AC_PRESENT) ? true : false;
 	}

 	return false;
 }

 static int bq24735_charger_is_charging(struct bq24735 *charger)
 {
 	int ret;

 	if (!bq24735_charger_is_present(charger))
 		return 0;

 	ret  = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
 	if (ret < 0)
 		return ret;

 	return !(ret & BQ24735_CHARGE_OPT_CHG_DISABLE);
 }

 static void bq24735_update(struct bq24735 *charger)
 {
 	mutex_lock(&charger->lock);

 	if (charger->charging && bq24735_charger_is_present(charger))
 		bq24735_enable_charging(charger);
 	else
 		bq24735_disable_charging(charger);

 	mutex_unlock(&charger->lock);

 	power_supply_changed(charger->charger);
 }

 static irqreturn_t bq24735_charger_isr(int irq, void *devid)
 {
 	struct power_supply *psy = devid;
 	struct bq24735 *charger = to_bq24735(psy);

 	bq24735_update(charger);

 	return IRQ_HANDLED;
 }

 static void bq24735_poll(struct work_struct *work)
 {
 	struct bq24735 *charger = container_of(work, struct bq24735, poll.work);

 	bq24735_update(charger);

 	schedule_delayed_work(&charger->poll,
 			      msecs_to_jiffies(charger->poll_interval));
 }

 static int bq24735_charger_get_property(struct power_supply *psy,
 					enum power_supply_property psp,
 					union power_supply_propval *val)
 {
 	struct bq24735 *charger = to_bq24735(psy);

 	switch (psp) {
 	case POWER_SUPPLY_PROP_ONLINE:
 		val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
 		break;
 	case POWER_SUPPLY_PROP_STATUS:
 		switch (bq24735_charger_is_charging(charger)) {
 		case 1:
 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
 			break;
 		case 0:
 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 			break;
 		default:
 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
 			break;
 		}
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int bq24735_charger_set_property(struct power_supply *psy,
 					enum power_supply_property psp,
 					const union power_supply_propval *val)
 {
 	struct bq24735 *charger = to_bq24735(psy);
 	int ret;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		switch (val->intval) {
 		case POWER_SUPPLY_STATUS_CHARGING:
 			mutex_lock(&charger->lock);
 			charger->charging = true;
 			ret = bq24735_enable_charging(charger);
 			mutex_unlock(&charger->lock);
 			if (ret)
 				return ret;
 			break;
 		case POWER_SUPPLY_STATUS_DISCHARGING:
 		case POWER_SUPPLY_STATUS_NOT_CHARGING:
 			mutex_lock(&charger->lock);
 			charger->charging = false;
 			ret = bq24735_disable_charging(charger);
 			mutex_unlock(&charger->lock);
 			if (ret)
 				return ret;
 			break;
 		default:
 			return -EINVAL;
 		}
 		power_supply_changed(psy);
 		break;
 	default:
 		return -EPERM;
 	}

 	return 0;
 }

 static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 {
 	struct bq24735_platform *pdata;
 	struct device_node *np = client->dev.of_node;
 	u32 val;
 	int ret;

 	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
 		dev_err(&client->dev,
 			"Memory alloc for bq24735 pdata failed\n");
 		return NULL;
 	}

 	ret = of_property_read_u32(np, "ti,charge-current", &val);
 	if (!ret)
 		pdata->charge_current = val;

 	ret = of_property_read_u32(np, "ti,charge-voltage", &val);
 	if (!ret)
 		pdata->charge_voltage = val;

 	ret = of_property_read_u32(np, "ti,input-current", &val);
 	if (!ret)
 		pdata->input_current = val;

 	pdata->ext_control = of_property_read_bool(np, "ti,external-control");

 	return pdata;
 }

 static int bq24735_charger_probe(struct i2c_client *client)
 {
 	int ret;
 	struct bq24735 *charger;
 	struct power_supply_desc *supply_desc;
 	struct power_supply_config psy_cfg = {};
 	char *name;

 	charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
 	if (!charger)
 		return -ENOMEM;

 	mutex_init(&charger->lock);
 	charger->charging = true;
 	charger->pdata = client->dev.platform_data;

 	if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
 		charger->pdata = bq24735_parse_dt_data(client);

 	if (!charger->pdata) {
 		dev_err(&client->dev, "no platform data provided\n");
 		return -EINVAL;
 	}

 	name = (char *)charger->pdata->name;
 	if (!name) {
 		name = devm_kasprintf(&client->dev, GFP_KERNEL,
 				      "bq24735@%s",
 				      dev_name(&client->dev));
 		if (!name) {
 			dev_err(&client->dev, "Failed to alloc device name\n");
 			return -ENOMEM;
 		}
 	}

 	charger->client = client;

 	supply_desc = &charger->charger_desc;

 	supply_desc->name = name;
 	supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
 	supply_desc->properties = bq24735_charger_properties;
 	supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
 	supply_desc->get_property = bq24735_charger_get_property;
 	supply_desc->set_property = bq24735_charger_set_property;
 	supply_desc->property_is_writeable =
 				bq24735_charger_property_is_writeable;

 	psy_cfg.supplied_to = charger->pdata->supplied_to;
 	psy_cfg.num_supplicants = charger->pdata->num_supplicants;
 	psy_cfg.of_node = client->dev.of_node;
 	psy_cfg.drv_data = charger;

 	i2c_set_clientdata(client, charger);

 	charger->status_gpio = devm_gpiod_get_optional(&client->dev,
 						       "ti,ac-detect",
 						       GPIOD_IN);
 	if (IS_ERR(charger->status_gpio)) {
 		ret = PTR_ERR(charger->status_gpio);
 		dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
 		return ret;
 	}

 	if (bq24735_charger_is_present(charger)) {
 		ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 		if (ret < 0) {
 			dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
 				ret);
 			return ret;
 		} else if (ret != 0x0040) {
 			dev_err(&client->dev,
 				"manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
 			return -ENODEV;
 		}

 		ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
 		if (ret < 0) {
 			dev_err(&client->dev, "Failed to read device id : %d\n", ret);
 			return ret;
 		} else if (ret != 0x000B) {
 			dev_err(&client->dev,
 				"device id mismatch. 0x000b != 0x%04x\n", ret);
 			return -ENODEV;
 		}

 		ret = bq24735_enable_charging(charger);
 		if (ret < 0) {
 			dev_err(&client->dev, "Failed to enable charging\n");
 			return ret;
 		}
 	}

 	charger->charger = devm_power_supply_register(&client->dev, supply_desc,
 						      &psy_cfg);
 	if (IS_ERR(charger->charger)) {
 		ret = PTR_ERR(charger->charger);
 		dev_err(&client->dev, "Failed to register power supply: %d\n",
 			ret);
 		return ret;
 	}

 	if (client->irq) {
 		ret = devm_request_threaded_irq(&client->dev, client->irq,
 						NULL, bq24735_charger_isr,
 						IRQF_TRIGGER_RISING |
 						IRQF_TRIGGER_FALLING |
 						IRQF_ONESHOT,
 						supply_desc->name,
 						charger->charger);
 		if (ret) {
 			dev_err(&client->dev,
 				"Unable to register IRQ %d err %d\n",
 				client->irq, ret);
 			return ret;
 		}
 	} else {
 		ret = device_property_read_u32(&client->dev, "poll-interval",
 					       &charger->poll_interval);
 		if (ret)
 			return 0;
 		if (!charger->poll_interval)
 			return 0;

 		ret = devm_delayed_work_autocancel(&client->dev, &charger->poll,
 						   bq24735_poll);
 		if (ret)
 			return ret;

 		schedule_delayed_work(&charger->poll,
 				      msecs_to_jiffies(charger->poll_interval));
 	}

 	return 0;
 }

 static const struct i2c_device_id bq24735_charger_id[] = {
 	{ "bq24735-charger", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);

 static const struct of_device_id bq24735_match_ids[] = {
 	{ .compatible = "ti,bq24735", },
 	{ /* end */ }
 };
 MODULE_DEVICE_TABLE(of, bq24735_match_ids);

 static struct i2c_driver bq24735_charger_driver = {
 	.driver = {
 		.name = "bq24735-charger",
 		.of_match_table = bq24735_match_ids,
 	},
 	.probe = bq24735_charger_probe,
 	.id_table = bq24735_charger_id,
 };

 module_i2c_driver(bq24735_charger_driver);

 MODULE_DESCRIPTION("bq24735 battery charging driver");
 MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* Battery charger driver for TI BQ24735
	*
	* Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
	*
	* 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;
	*
	* 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.
	*
	* 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.,
	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*/

	#include <linux/devm-helpers.h>
	#include <linux/err.h>
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/gpio/consumer.h>
	#include <linux/power_supply.h>
	#include <linux/slab.h>

	#include <linux/power/bq24735-charger.h>

	/* BQ24735 available commands and their respective masks */
	#define BQ24735_CHARGE_OPT 0x12
	#define BQ24735_CHARGE_CURRENT 0x14
	#define BQ24735_CHARGE_CURRENT_MASK 0x1fc0
	#define BQ24735_CHARGE_VOLTAGE 0x15
	#define BQ24735_CHARGE_VOLTAGE_MASK 0x7ff0
	#define BQ24735_INPUT_CURRENT 0x3f
	#define BQ24735_INPUT_CURRENT_MASK 0x1f80
	#define BQ24735_MANUFACTURER_ID 0xfe
	#define BQ24735_DEVICE_ID 0xff

	/* ChargeOptions bits of interest */
	#define BQ24735_CHARGE_OPT_CHG_DISABLE (1 << 0)
	#define BQ24735_CHARGE_OPT_AC_PRESENT (1 << 4)

	struct bq24735 {
	struct power_supply *charger;
	struct power_supply_desc charger_desc;
	struct i2c_client *client;
	struct bq24735_platform *pdata;
	struct mutex lock;
	struct gpio_desc *status_gpio;
	struct delayed_work poll;
	u32 poll_interval;
	bool charging;
	};

	static inline struct bq24735 to_bq24735(struct power_supply psy)
	{
	return power_supply_get_drvdata(psy);
	}

	static enum power_supply_property bq24735_charger_properties[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_ONLINE,
	};

	static int bq24735_charger_property_is_writeable(struct power_supply *psy,
	enum power_supply_property psp)
	{
	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	return 1;
	default:
	break;
	}

	return 0;
	}

	static inline int bq24735_write_word(struct i2c_client *client, u8 reg,
	u16 value)
	{
	return i2c_smbus_write_word_data(client, reg, value);
	}

	static inline int bq24735_read_word(struct i2c_client *client, u8 reg)
	{
	return i2c_smbus_read_word_data(client, reg);
	}

	static int bq24735_update_word(struct i2c_client *client, u8 reg,
	u16 mask, u16 value)
	{
	unsigned int tmp;
	int ret;

	ret = bq24735_read_word(client, reg);
	if (ret < 0)
	return ret;

	tmp = ret & ~mask;
	tmp \|= value & mask;

	return bq24735_write_word(client, reg, tmp);
	}

	static int bq24735_config_charger(struct bq24735 *charger)
	{
	struct bq24735_platform *pdata = charger->pdata;
	int ret;
	u16 value;

	if (pdata->ext_control)
	return 0;

	if (pdata->charge_current) {
	value = pdata->charge_current & BQ24735_CHARGE_CURRENT_MASK;

	ret = bq24735_write_word(charger->client,
	BQ24735_CHARGE_CURRENT, value);
	if (ret < 0) {
	dev_err(&charger->client->dev,
	"Failed to write charger current : %d\n",
	ret);
	return ret;
	}
	}

	if (pdata->charge_voltage) {
	value = pdata->charge_voltage & BQ24735_CHARGE_VOLTAGE_MASK;

	ret = bq24735_write_word(charger->client,
	BQ24735_CHARGE_VOLTAGE, value);
	if (ret < 0) {
	dev_err(&charger->client->dev,
	"Failed to write charger voltage : %d\n",
	ret);
	return ret;
	}
	}

	if (pdata->input_current) {
	value = pdata->input_current & BQ24735_INPUT_CURRENT_MASK;

	ret = bq24735_write_word(charger->client,
	BQ24735_INPUT_CURRENT, value);
	if (ret < 0) {
	dev_err(&charger->client->dev,
	"Failed to write input current : %d\n",
	ret);
	return ret;
	}
	}

	return 0;
	}

	static inline int bq24735_enable_charging(struct bq24735 *charger)
	{
	int ret;

	if (charger->pdata->ext_control)
	return 0;

	ret = bq24735_config_charger(charger);
	if (ret)
	return ret;

	return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
	BQ24735_CHARGE_OPT_CHG_DISABLE, 0);
	}

	static inline int bq24735_disable_charging(struct bq24735 *charger)
	{
	if (charger->pdata->ext_control)
	return 0;

	return bq24735_update_word(charger->client, BQ24735_CHARGE_OPT,
	BQ24735_CHARGE_OPT_CHG_DISABLE,
	BQ24735_CHARGE_OPT_CHG_DISABLE);
	}

	static bool bq24735_charger_is_present(struct bq24735 *charger)
	{
	if (charger->status_gpio) {
	return !gpiod_get_value_cansleep(charger->status_gpio);
	} else {
	int ac = 0;

	ac = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
	if (ac < 0) {
	dev_dbg(&charger->client->dev,
	"Failed to read charger options : %d\n",
	ac);
	return false;
	}
	return (ac & BQ24735_CHARGE_OPT_AC_PRESENT) ? true : false;
	}

	return false;
	}

	static int bq24735_charger_is_charging(struct bq24735 *charger)
	{
	int ret;

	if (!bq24735_charger_is_present(charger))
	return 0;

	ret = bq24735_read_word(charger->client, BQ24735_CHARGE_OPT);
	if (ret < 0)
	return ret;

	return !(ret & BQ24735_CHARGE_OPT_CHG_DISABLE);
	}

	static void bq24735_update(struct bq24735 *charger)
	{
	mutex_lock(&charger->lock);

	if (charger->charging && bq24735_charger_is_present(charger))
	bq24735_enable_charging(charger);
	else
	bq24735_disable_charging(charger);

	mutex_unlock(&charger->lock);

	power_supply_changed(charger->charger);
	}

	static irqreturn_t bq24735_charger_isr(int irq, void *devid)
	{
	struct power_supply *psy = devid;
	struct bq24735 *charger = to_bq24735(psy);

	bq24735_update(charger);

	return IRQ_HANDLED;
	}

	static void bq24735_poll(struct work_struct *work)
	{
	struct bq24735 *charger = container_of(work, struct bq24735, poll.work);

	bq24735_update(charger);

	schedule_delayed_work(&charger->poll,
	msecs_to_jiffies(charger->poll_interval));
	}

	static int bq24735_charger_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct bq24735 *charger = to_bq24735(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
	val->intval = bq24735_charger_is_present(charger) ? 1 : 0;
	break;
	case POWER_SUPPLY_PROP_STATUS:
	switch (bq24735_charger_is_charging(charger)) {
	case 1:
	val->intval = POWER_SUPPLY_STATUS_CHARGING;
	break;
	case 0:
	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	break;
	default:
	val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
	break;
	}
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int bq24735_charger_set_property(struct power_supply *psy,
	enum power_supply_property psp,
	const union power_supply_propval *val)
	{
	struct bq24735 *charger = to_bq24735(psy);
	int ret;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	switch (val->intval) {
	case POWER_SUPPLY_STATUS_CHARGING:
	mutex_lock(&charger->lock);
	charger->charging = true;
	ret = bq24735_enable_charging(charger);
	mutex_unlock(&charger->lock);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_STATUS_DISCHARGING:
	case POWER_SUPPLY_STATUS_NOT_CHARGING:
	mutex_lock(&charger->lock);
	charger->charging = false;
	ret = bq24735_disable_charging(charger);
	mutex_unlock(&charger->lock);
	if (ret)
	return ret;
	break;
	default:
	return -EINVAL;
	}
	power_supply_changed(psy);
	break;
	default:
	return -EPERM;
	}

	return 0;
	}

	static struct bq24735_platform bq24735_parse_dt_data(struct i2c_client client)
	{
	struct bq24735_platform *pdata;
	struct device_node *np = client->dev.of_node;
	u32 val;
	int ret;

	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
	dev_err(&client->dev,
	"Memory alloc for bq24735 pdata failed\n");
	return NULL;
	}

	ret = of_property_read_u32(np, "ti,charge-current", &val);
	if (!ret)
	pdata->charge_current = val;

	ret = of_property_read_u32(np, "ti,charge-voltage", &val);
	if (!ret)
	pdata->charge_voltage = val;

	ret = of_property_read_u32(np, "ti,input-current", &val);
	if (!ret)
	pdata->input_current = val;

	pdata->ext_control = of_property_read_bool(np, "ti,external-control");

	return pdata;
	}

	static int bq24735_charger_probe(struct i2c_client *client)
	{
	int ret;
	struct bq24735 *charger;
	struct power_supply_desc *supply_desc;
	struct power_supply_config psy_cfg = {};
	char *name;

	charger = devm_kzalloc(&client->dev, sizeof(*charger), GFP_KERNEL);
	if (!charger)
	return -ENOMEM;

	mutex_init(&charger->lock);
	charger->charging = true;
	charger->pdata = client->dev.platform_data;

	if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
	charger->pdata = bq24735_parse_dt_data(client);

	if (!charger->pdata) {
	dev_err(&client->dev, "no platform data provided\n");
	return -EINVAL;
	}

	name = (char *)charger->pdata->name;
	if (!name) {
	name = devm_kasprintf(&client->dev, GFP_KERNEL,
	"bq24735@%s",
	dev_name(&client->dev));
	if (!name) {
	dev_err(&client->dev, "Failed to alloc device name\n");
	return -ENOMEM;
	}
	}

	charger->client = client;

	supply_desc = &charger->charger_desc;

	supply_desc->name = name;
	supply_desc->type = POWER_SUPPLY_TYPE_MAINS;
	supply_desc->properties = bq24735_charger_properties;
	supply_desc->num_properties = ARRAY_SIZE(bq24735_charger_properties);
	supply_desc->get_property = bq24735_charger_get_property;
	supply_desc->set_property = bq24735_charger_set_property;
	supply_desc->property_is_writeable =
	bq24735_charger_property_is_writeable;

	psy_cfg.supplied_to = charger->pdata->supplied_to;
	psy_cfg.num_supplicants = charger->pdata->num_supplicants;
	psy_cfg.of_node = client->dev.of_node;
	psy_cfg.drv_data = charger;

	i2c_set_clientdata(client, charger);

	charger->status_gpio = devm_gpiod_get_optional(&client->dev,
	"ti,ac-detect",
	GPIOD_IN);
	if (IS_ERR(charger->status_gpio)) {
	ret = PTR_ERR(charger->status_gpio);
	dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
	return ret;
	}

	if (bq24735_charger_is_present(charger)) {
	ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to read manufacturer id : %d\n",
	ret);
	return ret;
	} else if (ret != 0x0040) {
	dev_err(&client->dev,
	"manufacturer id mismatch. 0x0040 != 0x%04x\n", ret);
	return -ENODEV;
	}

	ret = bq24735_read_word(client, BQ24735_DEVICE_ID);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to read device id : %d\n", ret);
	return ret;
	} else if (ret != 0x000B) {
	dev_err(&client->dev,
	"device id mismatch. 0x000b != 0x%04x\n", ret);
	return -ENODEV;
	}

	ret = bq24735_enable_charging(charger);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to enable charging\n");
	return ret;
	}
	}

	charger->charger = devm_power_supply_register(&client->dev, supply_desc,
	&psy_cfg);
	if (IS_ERR(charger->charger)) {
	ret = PTR_ERR(charger->charger);
	dev_err(&client->dev, "Failed to register power supply: %d\n",
	ret);
	return ret;
	}

	if (client->irq) {
	ret = devm_request_threaded_irq(&client->dev, client->irq,
	NULL, bq24735_charger_isr,
	IRQF_TRIGGER_RISING \|
	IRQF_TRIGGER_FALLING \|
	IRQF_ONESHOT,
	supply_desc->name,
	charger->charger);
	if (ret) {
	dev_err(&client->dev,
	"Unable to register IRQ %d err %d\n",
	client->irq, ret);
	return ret;
	}
	} else {
	ret = device_property_read_u32(&client->dev, "poll-interval",
	&charger->poll_interval);
	if (ret)
	return 0;
	if (!charger->poll_interval)
	return 0;

	ret = devm_delayed_work_autocancel(&client->dev, &charger->poll,
	bq24735_poll);
	if (ret)
	return ret;

	schedule_delayed_work(&charger->poll,
	msecs_to_jiffies(charger->poll_interval));
	}

	return 0;
	}

	static const struct i2c_device_id bq24735_charger_id[] = {
	{ "bq24735-charger", 0 },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, bq24735_charger_id);

	static const struct of_device_id bq24735_match_ids[] = {
	{ .compatible = "ti,bq24735", },
	{ /* end */ }
	};
	MODULE_DEVICE_TABLE(of, bq24735_match_ids);

	static struct i2c_driver bq24735_charger_driver = {
	.driver = {
	.name = "bq24735-charger",
	.of_match_table = bq24735_match_ids,
	},
	.probe = bq24735_charger_probe,
	.id_table = bq24735_charger_id,
	};

	module_i2c_driver(bq24735_charger_driver);

	MODULE_DESCRIPTION("bq24735 battery charging driver");
	MODULE_AUTHOR("Darbha Sriharsha <dsriharsha@nvidia.com>");
	MODULE_LICENSE("GPL v2");