[net-next-2.6.git] / drivers / power / bq20z75.c

/*
 * Gas Gauge driver for TI's BQ20Z75
 *
 * Copyright (c) 2010, NVIDIA 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.
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/i2c.h>
#include <linux/slab.h>

enum {
	REG_MANUFACTURER_DATA,
	REG_TEMPERATURE,
	REG_VOLTAGE,
	REG_CURRENT,
	REG_CAPACITY,
	REG_TIME_TO_EMPTY,
	REG_TIME_TO_FULL,
	REG_STATUS,
	REG_CYCLE_COUNT,
	REG_SERIAL_NUMBER,
	REG_REMAINING_CAPACITY,
	REG_FULL_CHARGE_CAPACITY,
	REG_DESIGN_CAPACITY,
	REG_DESIGN_VOLTAGE,
};

/* manufacturer access defines */
#define MANUFACTURER_ACCESS_STATUS	0x0006
#define MANUFACTURER_ACCESS_SLEEP	0x0011

/* battery status value bits */
#define BATTERY_DISCHARGING		0x40
#define BATTERY_FULL_CHARGED		0x20
#define BATTERY_FULL_DISCHARGED		0x10

#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
	.psp = _psp, \
	.addr = _addr, \
	.min_value = _min_value, \
	.max_value = _max_value, \
}

static const struct bq20z75_device_data {
	enum power_supply_property psp;
	u8 addr;
	int min_value;
	int max_value;
} bq20z75_data[] = {
	[REG_MANUFACTURER_DATA] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
	[REG_TEMPERATURE] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
	[REG_VOLTAGE] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
	[REG_CURRENT] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
			32767),
	[REG_CAPACITY] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
	[REG_REMAINING_CAPACITY] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
	[REG_FULL_CHARGE_CAPACITY] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
	[REG_TIME_TO_EMPTY] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
			65535),
	[REG_TIME_TO_FULL] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
			65535),
	[REG_STATUS] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
	[REG_CYCLE_COUNT] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
	[REG_DESIGN_CAPACITY] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
			65535),
	[REG_DESIGN_VOLTAGE] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
			65535),
	[REG_SERIAL_NUMBER] =
		BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
};

static enum power_supply_property bq20z75_properties[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_CYCLE_COUNT,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
	POWER_SUPPLY_PROP_ENERGY_NOW,
	POWER_SUPPLY_PROP_ENERGY_FULL,
	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
};

struct bq20z75_info {
	struct i2c_client	*client;
	struct power_supply	power_supply;
};

static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
{
	s32 ret;

	ret = i2c_smbus_read_word_data(client, address);
	if (ret < 0) {
		dev_err(&client->dev,
			"%s: i2c read at address 0x%x failed\n",
			__func__, address);
		return ret;
	}
	return le16_to_cpu(ret);
}

static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
	u16 value)
{
	s32 ret;

	ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
	if (ret < 0) {
		dev_err(&client->dev,
			"%s: i2c write to address 0x%x failed\n",
			__func__, address);
		return ret;
	}
	return 0;
}

static int bq20z75_get_battery_presence_and_health(
	struct i2c_client *client, enum power_supply_property psp,
	union power_supply_propval *val)
{
	s32 ret;

	/* Write to ManufacturerAccess with
	 * ManufacturerAccess command and then
	 * read the status */
	ret = bq20z75_write_word_data(client,
		bq20z75_data[REG_MANUFACTURER_DATA].addr,
		MANUFACTURER_ACCESS_STATUS);
	if (ret < 0)
		return ret;


	ret = bq20z75_read_word_data(client,
		bq20z75_data[REG_MANUFACTURER_DATA].addr);
	if (ret < 0)
		return ret;

	if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value ||
	    ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
		val->intval = 0;
		return 0;
	}

	/* Mask the upper nibble of 2nd byte and
	 * lower byte of response then
	 * shift the result by 8 to get status*/
	ret &= 0x0F00;
	ret >>= 8;
	if (psp == POWER_SUPPLY_PROP_PRESENT) {
		if (ret == 0x0F)
			/* battery removed */
			val->intval = 0;
		else
			val->intval = 1;
	} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
		if (ret == 0x09)
			val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
		else if (ret == 0x0B)
			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
		else if (ret == 0x0C)
			val->intval = POWER_SUPPLY_HEALTH_DEAD;
		else
			val->intval = POWER_SUPPLY_HEALTH_GOOD;
	}

	return 0;
}

static int bq20z75_get_battery_property(struct i2c_client *client,
	int reg_offset, enum power_supply_property psp,
	union power_supply_propval *val)
{
	s32 ret;

	ret = bq20z75_read_word_data(client,
		bq20z75_data[reg_offset].addr);
	if (ret < 0)
		return ret;

	/* returned values are 16 bit */
	if (bq20z75_data[reg_offset].min_value < 0)
		ret = (s16)ret;

	if (ret >= bq20z75_data[reg_offset].min_value &&
	    ret <= bq20z75_data[reg_offset].max_value) {
		val->intval = ret;
		if (psp == POWER_SUPPLY_PROP_STATUS) {
			if (ret & BATTERY_FULL_CHARGED)
				val->intval = POWER_SUPPLY_STATUS_FULL;
			else if (ret & BATTERY_FULL_DISCHARGED)
				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
			else if (ret & BATTERY_DISCHARGING)
				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
			else
				val->intval = POWER_SUPPLY_STATUS_CHARGING;
		}
	} else {
		if (psp == POWER_SUPPLY_PROP_STATUS)
			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
		else
			val->intval = 0;
	}

	return 0;
}

static void  bq20z75_unit_adjustment(struct i2c_client *client,
	enum power_supply_property psp, union power_supply_propval *val)
{
#define BASE_UNIT_CONVERSION		1000
#define BATTERY_MODE_CAP_MULT_WATT	(10 * BASE_UNIT_CONVERSION)
#define TIME_UNIT_CONVERSION		600
#define TEMP_KELVIN_TO_CELCIUS		2731
	switch (psp) {
	case POWER_SUPPLY_PROP_ENERGY_NOW:
	case POWER_SUPPLY_PROP_ENERGY_FULL:
	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
		val->intval *= BATTERY_MODE_CAP_MULT_WATT;
		break;

	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		val->intval *= BASE_UNIT_CONVERSION;
		break;

	case POWER_SUPPLY_PROP_TEMP:
		/* bq20z75 provides battery tempreture in 0.1°K
		 * so convert it to 0.1°C */
		val->intval -= TEMP_KELVIN_TO_CELCIUS;
		val->intval *= 10;
		break;

	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
		val->intval *= TIME_UNIT_CONVERSION;
		break;

	default:
		dev_dbg(&client->dev,
			"%s: no need for unit conversion %d\n", __func__, psp);
	}
}

static int bq20z75_get_battery_capacity(struct i2c_client *client,
	int reg_offset, enum power_supply_property psp,
	union power_supply_propval *val)
{
	s32 ret;

	ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
	if (ret < 0)
		return ret;

	if (psp == POWER_SUPPLY_PROP_CAPACITY) {
		/* bq20z75 spec says that this can be >100 %
		* even if max value is 100 % */
		val->intval = min(ret, 100);
	} else
		val->intval = ret;

	return 0;
}

static char bq20z75_serial[5];
static int bq20z75_get_battery_serial_number(struct i2c_client *client,
	union power_supply_propval *val)
{
	int ret;

	ret = bq20z75_read_word_data(client,
		bq20z75_data[REG_SERIAL_NUMBER].addr);
	if (ret < 0)
		return ret;

	ret = sprintf(bq20z75_serial, "%04x", ret);
	val->strval = bq20z75_serial;

	return 0;
}

static int bq20z75_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
{
	int count;
	int ret;
	struct bq20z75_info *bq20z75_device = container_of(psy,
				struct bq20z75_info, power_supply);
	struct i2c_client *client = bq20z75_device->client;

	switch (psp) {
	case POWER_SUPPLY_PROP_PRESENT:
	case POWER_SUPPLY_PROP_HEALTH:
		ret = bq20z75_get_battery_presence_and_health(client, psp, val);
		if (ret)
			return ret;
		break;

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

	case POWER_SUPPLY_PROP_ENERGY_NOW:
	case POWER_SUPPLY_PROP_ENERGY_FULL:
	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
	case POWER_SUPPLY_PROP_CAPACITY:
		for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
			if (psp == bq20z75_data[count].psp)
				break;
		}

		ret = bq20z75_get_battery_capacity(client, count, psp, val);
		if (ret)
			return ret;

		break;

	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
		ret = bq20z75_get_battery_serial_number(client, val);
		if (ret)
			return ret;
		break;

	case POWER_SUPPLY_PROP_STATUS:
	case POWER_SUPPLY_PROP_CYCLE_COUNT:
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	case POWER_SUPPLY_PROP_TEMP:
	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
		for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
			if (psp == bq20z75_data[count].psp)
				break;
		}

		ret = bq20z75_get_battery_property(client, count, psp, val);
		if (ret)
			return ret;

		break;

	default:
		dev_err(&client->dev,
			"%s: INVALID property\n", __func__);
		return -EINVAL;
	}

	/* Convert units to match requirements for power supply class */
	bq20z75_unit_adjustment(client, psp, val);

	dev_dbg(&client->dev,
		"%s: property = %d, value = %d\n", __func__, psp, val->intval);

	return 0;
}

static int bq20z75_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
{
	struct bq20z75_info *bq20z75_device;
	int rc;

	bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
	if (!bq20z75_device)
		return -ENOMEM;

	bq20z75_device->client = client;
	bq20z75_device->power_supply.name = "battery";
	bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
	bq20z75_device->power_supply.properties = bq20z75_properties;
	bq20z75_device->power_supply.num_properties =
		ARRAY_SIZE(bq20z75_properties);
	bq20z75_device->power_supply.get_property = bq20z75_get_property;

	i2c_set_clientdata(client, bq20z75_device);

	rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
	if (rc) {
		dev_err(&client->dev,
			"%s: Failed to register power supply\n", __func__);
		kfree(bq20z75_device);
		return rc;
	}

	dev_info(&client->dev,
		"%s: battery gas gauge device registered\n", client->name);

	return 0;
}

static int bq20z75_remove(struct i2c_client *client)
{
	struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);

	power_supply_unregister(&bq20z75_device->power_supply);
	kfree(bq20z75_device);
	bq20z75_device = NULL;

	return 0;
}

#if defined CONFIG_PM
static int bq20z75_suspend(struct i2c_client *client,
	pm_message_t state)
{
	s32 ret;

	/* write to manufacturer access with sleep command */
	ret = bq20z75_write_word_data(client,
		bq20z75_data[REG_MANUFACTURER_DATA].addr,
		MANUFACTURER_ACCESS_SLEEP);
	if (ret < 0)
		return ret;

	return 0;
}
#else
#define bq20z75_suspend		NULL
#endif
/* any smbus transaction will wake up bq20z75 */
#define bq20z75_resume		NULL

static const struct i2c_device_id bq20z75_id[] = {
	{ "bq20z75", 0 },
	{}
};

static struct i2c_driver bq20z75_battery_driver = {
	.probe		= bq20z75_probe,
	.remove		= bq20z75_remove,
	.suspend	= bq20z75_suspend,
	.resume		= bq20z75_resume,
	.id_table	= bq20z75_id,
	.driver = {
		.name	= "bq20z75-battery",
	},
};

static int __init bq20z75_battery_init(void)
{
	return i2c_add_driver(&bq20z75_battery_driver);
}
module_init(bq20z75_battery_init);

static void __exit bq20z75_battery_exit(void)
{
	i2c_del_driver(&bq20z75_battery_driver);
}
module_exit(bq20z75_battery_exit);

MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
a7640bfa RK	1	/*
	2	* Gas Gauge driver for TI's BQ20Z75
	3	*
	4	* Copyright (c) 2010, NVIDIA Corporation.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but WITHOUT
	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	14	* more details.
	15	*
	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; if not, write to the Free Software Foundation, Inc.,
	18	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	19	*/
	20
	21	#include <linux/init.h>
	22	#include <linux/module.h>
	23	#include <linux/kernel.h>
	24	#include <linux/err.h>
	25	#include <linux/power_supply.h>
	26	#include <linux/i2c.h>
	27	#include <linux/slab.h>
	28
	29	enum {
	30	REG_MANUFACTURER_DATA,
	31	REG_TEMPERATURE,
	32	REG_VOLTAGE,
	33	REG_CURRENT,
	34	REG_CAPACITY,
	35	REG_TIME_TO_EMPTY,
	36	REG_TIME_TO_FULL,
	37	REG_STATUS,
	38	REG_CYCLE_COUNT,
d3ab61ec RK	39	REG_SERIAL_NUMBER,
	40	REG_REMAINING_CAPACITY,
	41	REG_FULL_CHARGE_CAPACITY,
	42	REG_DESIGN_CAPACITY,
	43	REG_DESIGN_VOLTAGE,
a7640bfa RK	44	};
	45
	46	/* manufacturer access defines */
	47	#define MANUFACTURER_ACCESS_STATUS 0x0006
	48	#define MANUFACTURER_ACCESS_SLEEP 0x0011
	49
	50	/* battery status value bits */
d3ab61ec	51	#define BATTERY_DISCHARGING 0x40
a7640bfa RK	52	#define BATTERY_FULL_CHARGED 0x20
	53	#define BATTERY_FULL_DISCHARGED 0x10
	54
	55	#define BQ20Z75_DATA(_psp, _addr, _min_value, _max_value) { \
	56	.psp = _psp, \
	57	.addr = _addr, \
	58	.min_value = _min_value, \
	59	.max_value = _max_value, \
	60	}
	61
	62	static const struct bq20z75_device_data {
	63	enum power_supply_property psp;
	64	u8 addr;
	65	int min_value;
	66	int max_value;
	67	} bq20z75_data[] = {
	68	[REG_MANUFACTURER_DATA] =
	69	BQ20Z75_DATA(POWER_SUPPLY_PROP_PRESENT, 0x00, 0, 65535),
	70	[REG_TEMPERATURE] =
	71	BQ20Z75_DATA(POWER_SUPPLY_PROP_TEMP, 0x08, 0, 65535),
	72	[REG_VOLTAGE] =
	73	BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_NOW, 0x09, 0, 20000),
	74	[REG_CURRENT] =
	75	BQ20Z75_DATA(POWER_SUPPLY_PROP_CURRENT_NOW, 0x0A, -32768,
	76	32767),
	77	[REG_CAPACITY] =
	78	BQ20Z75_DATA(POWER_SUPPLY_PROP_CAPACITY, 0x0E, 0, 100),
d3ab61ec RK	79	[REG_REMAINING_CAPACITY] =
	80	BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_NOW, 0x0F, 0, 65535),
	81	[REG_FULL_CHARGE_CAPACITY] =
	82	BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL, 0x10, 0, 65535),
a7640bfa RK	83	[REG_TIME_TO_EMPTY] =
	84	BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, 0x12, 0,
	85	65535),
	86	[REG_TIME_TO_FULL] =
	87	BQ20Z75_DATA(POWER_SUPPLY_PROP_TIME_TO_FULL_AVG, 0x13, 0,
	88	65535),
	89	[REG_STATUS] =
	90	BQ20Z75_DATA(POWER_SUPPLY_PROP_STATUS, 0x16, 0, 65535),
	91	[REG_CYCLE_COUNT] =
	92	BQ20Z75_DATA(POWER_SUPPLY_PROP_CYCLE_COUNT, 0x17, 0, 65535),
d3ab61ec RK	93	[REG_DESIGN_CAPACITY] =
	94	BQ20Z75_DATA(POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN, 0x18, 0,
	95	65535),
	96	[REG_DESIGN_VOLTAGE] =
	97	BQ20Z75_DATA(POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN, 0x19, 0,
	98	65535),
a7640bfa RK	99	[REG_SERIAL_NUMBER] =
	100	BQ20Z75_DATA(POWER_SUPPLY_PROP_SERIAL_NUMBER, 0x1C, 0, 65535),
	101	};
	102
	103	static enum power_supply_property bq20z75_properties[] = {
	104	POWER_SUPPLY_PROP_STATUS,
	105	POWER_SUPPLY_PROP_HEALTH,
	106	POWER_SUPPLY_PROP_PRESENT,
	107	POWER_SUPPLY_PROP_TECHNOLOGY,
	108	POWER_SUPPLY_PROP_CYCLE_COUNT,
	109	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	110	POWER_SUPPLY_PROP_CURRENT_NOW,
	111	POWER_SUPPLY_PROP_CAPACITY,
	112	POWER_SUPPLY_PROP_TEMP,
	113	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
	114	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
	115	POWER_SUPPLY_PROP_SERIAL_NUMBER,
d3ab61ec RK	116	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
	117	POWER_SUPPLY_PROP_ENERGY_NOW,
	118	POWER_SUPPLY_PROP_ENERGY_FULL,
	119	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
a7640bfa RK	120	};
	121
	122	struct bq20z75_info {
	123	struct i2c_client *client;
	124	struct power_supply power_supply;
	125	};
	126
d3ab61ec RK	127	static int bq20z75_read_word_data(struct i2c_client *client, u8 address)
	128	{
	129	s32 ret;
	130
	131	ret = i2c_smbus_read_word_data(client, address);
	132	if (ret < 0) {
	133	dev_err(&client->dev,
	134	"%s: i2c read at address 0x%x failed\n",
	135	__func__, address);
	136	return ret;
	137	}
	138	return le16_to_cpu(ret);
	139	}
	140
	141	static int bq20z75_write_word_data(struct i2c_client *client, u8 address,
	142	u16 value)
	143	{
	144	s32 ret;
	145
	146	ret = i2c_smbus_write_word_data(client, address, le16_to_cpu(value));
	147	if (ret < 0) {
	148	dev_err(&client->dev,
	149	"%s: i2c write to address 0x%x failed\n",
	150	__func__, address);
	151	return ret;
	152	}
	153	return 0;
	154	}
	155
a7640bfa RK	156	static int bq20z75_get_battery_presence_and_health(
	157	struct i2c_client *client, enum power_supply_property psp,
	158	union power_supply_propval *val)
	159	{
	160	s32 ret;
	161
	162	/* Write to ManufacturerAccess with
	163	* ManufacturerAccess command and then
	164	* read the status */
d3ab61ec	165	ret = bq20z75_write_word_data(client,
a7640bfa RK	166	bq20z75_data[REG_MANUFACTURER_DATA].addr,
a7640bfa RK	167	MANUFACTURER_ACCESS_STATUS);
d3ab61ec RK	168	if (ret < 0)
d3ab61ec RK	169	return ret;
a7640bfa	170
d3ab61ec RK	171
d3ab61ec RK	172	ret = bq20z75_read_word_data(client,
a7640bfa	173	bq20z75_data[REG_MANUFACTURER_DATA].addr);
d3ab61ec RK	174	if (ret < 0)
d3ab61ec RK	175	return ret;
a7640bfa RK	176
	177	if (ret < bq20z75_data[REG_MANUFACTURER_DATA].min_value \|\|
	178	ret > bq20z75_data[REG_MANUFACTURER_DATA].max_value) {
	179	val->intval = 0;
	180	return 0;
	181	}
	182
	183	/* Mask the upper nibble of 2nd byte and
	184	* lower byte of response then
	185	* shift the result by 8 to get status*/
	186	ret &= 0x0F00;
	187	ret >>= 8;
	188	if (psp == POWER_SUPPLY_PROP_PRESENT) {
	189	if (ret == 0x0F)
	190	/* battery removed */
	191	val->intval = 0;
	192	else
	193	val->intval = 1;
	194	} else if (psp == POWER_SUPPLY_PROP_HEALTH) {
	195	if (ret == 0x09)
	196	val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
	197	else if (ret == 0x0B)
	198	val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
	199	else if (ret == 0x0C)
	200	val->intval = POWER_SUPPLY_HEALTH_DEAD;
	201	else
	202	val->intval = POWER_SUPPLY_HEALTH_GOOD;
	203	}
	204
	205	return 0;
	206	}
	207
	208	static int bq20z75_get_battery_property(struct i2c_client *client,
	209	int reg_offset, enum power_supply_property psp,
	210	union power_supply_propval *val)
	211	{
	212	s32 ret;
	213
d3ab61ec	214	ret = bq20z75_read_word_data(client,
a7640bfa	215	bq20z75_data[reg_offset].addr);
d3ab61ec RK	216	if (ret < 0)
	217	return ret;
	218
	219	/* returned values are 16 bit */
	220	if (bq20z75_data[reg_offset].min_value < 0)
	221	ret = (s16)ret;
a7640bfa RK	222
	223	if (ret >= bq20z75_data[reg_offset].min_value &&
	224	ret <= bq20z75_data[reg_offset].max_value) {
	225	val->intval = ret;
	226	if (psp == POWER_SUPPLY_PROP_STATUS) {
d3ab61ec	227	if (ret & BATTERY_FULL_CHARGED)
a7640bfa RK	228	val->intval = POWER_SUPPLY_STATUS_FULL;
	229	else if (ret & BATTERY_FULL_DISCHARGED)
	230	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
d3ab61ec	231	else if (ret & BATTERY_DISCHARGING)
a7640bfa	232	val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
d3ab61ec RK	233	else
d3ab61ec RK	234	val->intval = POWER_SUPPLY_STATUS_CHARGING;
a7640bfa	235	}
a7640bfa RK	236	} else {
	237	if (psp == POWER_SUPPLY_PROP_STATUS)
	238	val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
	239	else
	240	val->intval = 0;
	241	}
	242
	243	return 0;
	244	}
	245
d3ab61ec RK	246	static void bq20z75_unit_adjustment(struct i2c_client *client,
	247	enum power_supply_property psp, union power_supply_propval *val)
	248	{
	249	#define BASE_UNIT_CONVERSION 1000
	250	#define BATTERY_MODE_CAP_MULT_WATT (10 * BASE_UNIT_CONVERSION)
	251	#define TIME_UNIT_CONVERSION 600
	252	#define TEMP_KELVIN_TO_CELCIUS 2731
	253	switch (psp) {
	254	case POWER_SUPPLY_PROP_ENERGY_NOW:
	255	case POWER_SUPPLY_PROP_ENERGY_FULL:
	256	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
	257	val->intval *= BATTERY_MODE_CAP_MULT_WATT;
	258	break;
	259
	260	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	261	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
	262	case POWER_SUPPLY_PROP_CURRENT_NOW:
	263	val->intval *= BASE_UNIT_CONVERSION;
	264	break;
	265
	266	case POWER_SUPPLY_PROP_TEMP:
	267	/* bq20z75 provides battery tempreture in 0.1°K
	268	* so convert it to 0.1°C */
	269	val->intval -= TEMP_KELVIN_TO_CELCIUS;
	270	val->intval *= 10;
	271	break;
	272
	273	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	274	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
	275	val->intval *= TIME_UNIT_CONVERSION;
	276	break;
	277
	278	default:
	279	dev_dbg(&client->dev,
	280	"%s: no need for unit conversion %d\n", __func__, psp);
	281	}
	282	}
	283
a7640bfa	284	static int bq20z75_get_battery_capacity(struct i2c_client *client,
d3ab61ec	285	int reg_offset, enum power_supply_property psp,
a7640bfa RK	286	union power_supply_propval *val)
	287	{
	288	s32 ret;
	289
d3ab61ec RK	290	ret = bq20z75_read_word_data(client, bq20z75_data[reg_offset].addr);
	291	if (ret < 0)
	292	return ret;
a7640bfa	293
d3ab61ec RK	294	if (psp == POWER_SUPPLY_PROP_CAPACITY) {
	295	/* bq20z75 spec says that this can be >100 %
	296	* even if max value is 100 % */
	297	val->intval = min(ret, 100);
	298	} else
	299	val->intval = ret;
	300
	301	return 0;
	302	}
	303
	304	static char bq20z75_serial[5];
	305	static int bq20z75_get_battery_serial_number(struct i2c_client *client,
	306	union power_supply_propval *val)
	307	{
	308	int ret;
	309
	310	ret = bq20z75_read_word_data(client,
	311	bq20z75_data[REG_SERIAL_NUMBER].addr);
	312	if (ret < 0)
	313	return ret;
	314
	315	ret = sprintf(bq20z75_serial, "%04x", ret);
	316	val->strval = bq20z75_serial;
a7640bfa RK	317
	318	return 0;
	319	}
	320
	321	static int bq20z75_get_property(struct power_supply *psy,
	322	enum power_supply_property psp,
	323	union power_supply_propval *val)
	324	{
	325	int count;
	326	int ret;
	327	struct bq20z75_info *bq20z75_device = container_of(psy,
	328	struct bq20z75_info, power_supply);
	329	struct i2c_client *client = bq20z75_device->client;
	330
	331	switch (psp) {
	332	case POWER_SUPPLY_PROP_PRESENT:
	333	case POWER_SUPPLY_PROP_HEALTH:
	334	ret = bq20z75_get_battery_presence_and_health(client, psp, val);
	335	if (ret)
	336	return ret;
	337	break;
	338
	339	case POWER_SUPPLY_PROP_TECHNOLOGY:
	340	val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
	341	break;
	342
d3ab61ec RK	343	case POWER_SUPPLY_PROP_ENERGY_NOW:
	344	case POWER_SUPPLY_PROP_ENERGY_FULL:
	345	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
a7640bfa	346	case POWER_SUPPLY_PROP_CAPACITY:
d3ab61ec RK	347	for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
	348	if (psp == bq20z75_data[count].psp)
	349	break;
	350	}
	351
	352	ret = bq20z75_get_battery_capacity(client, count, psp, val);
	353	if (ret)
	354	return ret;
	355
	356	break;
	357
	358	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
	359	ret = bq20z75_get_battery_serial_number(client, val);
a7640bfa RK	360	if (ret)
	361	return ret;
	362	break;
	363
	364	case POWER_SUPPLY_PROP_STATUS:
	365	case POWER_SUPPLY_PROP_CYCLE_COUNT:
	366	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	367	case POWER_SUPPLY_PROP_CURRENT_NOW:
	368	case POWER_SUPPLY_PROP_TEMP:
	369	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	370	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
d3ab61ec	371	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
a7640bfa RK	372	for (count = 0; count < ARRAY_SIZE(bq20z75_data); count++) {
	373	if (psp == bq20z75_data[count].psp)
	374	break;
	375	}
	376
	377	ret = bq20z75_get_battery_property(client, count, psp, val);
	378	if (ret)
	379	return ret;
d3ab61ec	380
a7640bfa RK	381	break;
	382
	383	default:
	384	dev_err(&client->dev,
	385	"%s: INVALID property\n", __func__);
	386	return -EINVAL;
	387	}
	388
d3ab61ec RK	389	/* Convert units to match requirements for power supply class */
	390	bq20z75_unit_adjustment(client, psp, val);
	391
a7640bfa RK	392	dev_dbg(&client->dev,
	393	"%s: property = %d, value = %d\n", __func__, psp, val->intval);
	394
	395	return 0;
	396	}
	397
	398	static int bq20z75_probe(struct i2c_client *client,
	399	const struct i2c_device_id *id)
	400	{
	401	struct bq20z75_info *bq20z75_device;
	402	int rc;
	403
	404	bq20z75_device = kzalloc(sizeof(struct bq20z75_info), GFP_KERNEL);
	405	if (!bq20z75_device)
	406	return -ENOMEM;
	407
	408	bq20z75_device->client = client;
	409	bq20z75_device->power_supply.name = "battery";
	410	bq20z75_device->power_supply.type = POWER_SUPPLY_TYPE_BATTERY;
	411	bq20z75_device->power_supply.properties = bq20z75_properties;
	412	bq20z75_device->power_supply.num_properties =
	413	ARRAY_SIZE(bq20z75_properties);
	414	bq20z75_device->power_supply.get_property = bq20z75_get_property;
	415
	416	i2c_set_clientdata(client, bq20z75_device);
	417
	418	rc = power_supply_register(&client->dev, &bq20z75_device->power_supply);
	419	if (rc) {
	420	dev_err(&client->dev,
	421	"%s: Failed to register power supply\n", __func__);
	422	kfree(bq20z75_device);
	423	return rc;
	424	}
	425
	426	dev_info(&client->dev,
	427	"%s: battery gas gauge device registered\n", client->name);
	428
	429	return 0;
	430	}
	431
	432	static int bq20z75_remove(struct i2c_client *client)
	433	{
	434	struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client);
	435
	436	power_supply_unregister(&bq20z75_device->power_supply);
	437	kfree(bq20z75_device);
	438	bq20z75_device = NULL;
	439
	440	return 0;
	441	}
	442
	443	#if defined CONFIG_PM
	444	static int bq20z75_suspend(struct i2c_client *client,
	445	pm_message_t state)
	446	{
	447	s32 ret;
	448
	449	/* write to manufacturer access with sleep command */
d3ab61ec	450	ret = bq20z75_write_word_data(client,
a7640bfa RK	451	bq20z75_data[REG_MANUFACTURER_DATA].addr,
a7640bfa RK	452	MANUFACTURER_ACCESS_SLEEP);
d3ab61ec RK	453	if (ret < 0)
d3ab61ec RK	454	return ret;
a7640bfa RK	455
	456	return 0;
	457	}
	458	#else
	459	#define bq20z75_suspend NULL
	460	#endif
	461	/* any smbus transaction will wake up bq20z75 */
	462	#define bq20z75_resume NULL
	463
	464	static const struct i2c_device_id bq20z75_id[] = {
	465	{ "bq20z75", 0 },
	466	{}
	467	};
	468
	469	static struct i2c_driver bq20z75_battery_driver = {
	470	.probe = bq20z75_probe,
	471	.remove = bq20z75_remove,
	472	.suspend = bq20z75_suspend,
	473	.resume = bq20z75_resume,
	474	.id_table = bq20z75_id,
	475	.driver = {
	476	.name = "bq20z75-battery",
	477	},
	478	};
	479
	480	static int __init bq20z75_battery_init(void)
	481	{
	482	return i2c_add_driver(&bq20z75_battery_driver);
	483	}
	484	module_init(bq20z75_battery_init);
	485
	486	static void __exit bq20z75_battery_exit(void)
	487	{
	488	i2c_del_driver(&bq20z75_battery_driver);
	489	}
	490	module_exit(bq20z75_battery_exit);
	491
	492	MODULE_DESCRIPTION("BQ20z75 battery monitor driver");
	493	MODULE_LICENSE("GPL");