drivers/power/max17042_battery.c

/*
 * Fuel gauge driver for Maxim 17042 / 8966 / 8997
 *  Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
 *
 * Copyright (C) 2011 Samsung Electronics
 * MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * This driver is based on max17040_battery.c
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/power_supply.h>
#include <linux/power/max17042_battery.h>

enum max17042_register {
	MAX17042_STATUS		= 0x00,
	MAX17042_VALRT_Th	= 0x01,
	MAX17042_TALRT_Th	= 0x02,
	MAX17042_SALRT_Th	= 0x03,
	MAX17042_AtRate		= 0x04,
	MAX17042_RepCap		= 0x05,
	MAX17042_RepSOC		= 0x06,
	MAX17042_Age		= 0x07,
	MAX17042_TEMP		= 0x08,
	MAX17042_VCELL		= 0x09,
	MAX17042_Current	= 0x0A,
	MAX17042_AvgCurrent	= 0x0B,
	MAX17042_Qresidual	= 0x0C,
	MAX17042_SOC		= 0x0D,
	MAX17042_AvSOC		= 0x0E,
	MAX17042_RemCap		= 0x0F,
	MAX17402_FullCAP	= 0x10,
	MAX17042_TTE		= 0x11,
	MAX17042_V_empty	= 0x12,

	MAX17042_RSLOW		= 0x14,

	MAX17042_AvgTA		= 0x16,
	MAX17042_Cycles		= 0x17,
	MAX17042_DesignCap	= 0x18,
	MAX17042_AvgVCELL	= 0x19,
	MAX17042_MinMaxTemp	= 0x1A,
	MAX17042_MinMaxVolt	= 0x1B,
	MAX17042_MinMaxCurr	= 0x1C,
	MAX17042_CONFIG		= 0x1D,
	MAX17042_ICHGTerm	= 0x1E,
	MAX17042_AvCap		= 0x1F,
	MAX17042_ManName	= 0x20,
	MAX17042_DevName	= 0x21,
	MAX17042_DevChem	= 0x22,

	MAX17042_TempNom	= 0x24,
	MAX17042_TempCold	= 0x25,
	MAX17042_TempHot	= 0x26,
	MAX17042_AIN		= 0x27,
	MAX17042_LearnCFG	= 0x28,
	MAX17042_SHFTCFG	= 0x29,
	MAX17042_RelaxCFG	= 0x2A,
	MAX17042_MiscCFG	= 0x2B,
	MAX17042_TGAIN		= 0x2C,
	MAx17042_TOFF		= 0x2D,
	MAX17042_CGAIN		= 0x2E,
	MAX17042_COFF		= 0x2F,

	MAX17042_Q_empty	= 0x33,
	MAX17042_T_empty	= 0x34,

	MAX17042_RCOMP0		= 0x38,
	MAX17042_TempCo		= 0x39,
	MAX17042_Rx		= 0x3A,
	MAX17042_T_empty0	= 0x3B,
	MAX17042_TaskPeriod	= 0x3C,
	MAX17042_FSTAT		= 0x3D,

	MAX17042_SHDNTIMER	= 0x3F,

	MAX17042_VFRemCap	= 0x4A,

	MAX17042_QH		= 0x4D,
	MAX17042_QL		= 0x4E,
};

struct max17042_chip {
	struct i2c_client *client;
	struct power_supply battery;
	struct max17042_platform_data *pdata;
};

static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
{
	int ret = i2c_smbus_write_word_data(client, reg, value);

	if (ret < 0)
		dev_err(&client->dev, "%s: err %d\n", __func__, ret);

	return ret;
}

static int max17042_read_reg(struct i2c_client *client, u8 reg)
{
	int ret = i2c_smbus_read_word_data(client, reg);

	if (ret < 0)
		dev_err(&client->dev, "%s: err %d\n", __func__, ret);

	return ret;
}

static enum power_supply_property max17042_battery_props[] = {
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_CAPACITY,
};

static int max17042_get_property(struct power_supply *psy,
			    enum power_supply_property psp,
			    union power_supply_propval *val)
{
	struct max17042_chip *chip = container_of(psy,
				struct max17042_chip, battery);

	switch (psp) {
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		val->intval = max17042_read_reg(chip->client,
				MAX17042_VCELL) * 83; /* 1000 / 12 = 83 */
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
		val->intval = max17042_read_reg(chip->client,
				MAX17042_AvgVCELL) * 83;
		break;
	case POWER_SUPPLY_PROP_CAPACITY:
		val->intval = max17042_read_reg(chip->client,
				MAX17042_SOC) / 256;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

static int __devinit max17042_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct max17042_chip *chip;
	int ret;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
		return -EIO;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	chip->client = client;
	chip->pdata = client->dev.platform_data;

	i2c_set_clientdata(client, chip);

	chip->battery.name		= "max17042_battery";
	chip->battery.type		= POWER_SUPPLY_TYPE_BATTERY;
	chip->battery.get_property	= max17042_get_property;
	chip->battery.properties	= max17042_battery_props;
	chip->battery.num_properties	= ARRAY_SIZE(max17042_battery_props);

	ret = power_supply_register(&client->dev, &chip->battery);
	if (ret) {
		dev_err(&client->dev, "failed: power supply register\n");
		i2c_set_clientdata(client, NULL);
		kfree(chip);
		return ret;
	}

	if (!chip->pdata->enable_current_sense) {
		max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
		max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
		max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
	}

	return 0;
}

static int __devexit max17042_remove(struct i2c_client *client)
{
	struct max17042_chip *chip = i2c_get_clientdata(client);

	power_supply_unregister(&chip->battery);
	i2c_set_clientdata(client, NULL);
	kfree(chip);
	return 0;
}

static const struct i2c_device_id max17042_id[] = {
	{ "max17042", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max17042_id);

static struct i2c_driver max17042_i2c_driver = {
	.driver	= {
		.name	= "max17042",
	},
	.probe		= max17042_probe,
	.remove		= __devexit_p(max17042_remove),
	.id_table	= max17042_id,
};

static int __init max17042_init(void)
{
	return i2c_add_driver(&max17042_i2c_driver);
}
module_init(max17042_init);

static void __exit max17042_exit(void)
{
	i2c_del_driver(&max17042_i2c_driver);
}
module_exit(max17042_exit);

MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
MODULE_LICENSE("GPL");