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/*
* 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>
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 void max17042_set_reg(struct i2c_client *client,
struct max17042_reg_data *data, int size)
{
int i;
for (i = 0; i < size; i++)
max17042_write_reg(client, data[i].addr, data[i].data);
}
static enum power_supply_property max17042_battery_props[] = {
POWER_SUPPLY_PROP_PRESENT,
POWER_SUPPLY_PROP_CYCLE_COUNT,
POWER_SUPPLY_PROP_VOLTAGE_MAX,
POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
POWER_SUPPLY_PROP_VOLTAGE_NOW,
POWER_SUPPLY_PROP_VOLTAGE_AVG,
POWER_SUPPLY_PROP_CAPACITY,
POWER_SUPPLY_PROP_CHARGE_FULL,
POWER_SUPPLY_PROP_TEMP,
POWER_SUPPLY_PROP_CURRENT_NOW,
POWER_SUPPLY_PROP_CURRENT_AVG,
};
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_PRESENT:
val->intval = max17042_read_reg(chip->client,
MAX17042_STATUS);
if (val->intval & MAX17042_STATUS_BattAbsent)
val->intval = 0;
else
val->intval = 1;
break;
case POWER_SUPPLY_PROP_CYCLE_COUNT:
val->intval = max17042_read_reg(chip->client,
MAX17042_Cycles);
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX:
val->intval = max17042_read_reg(chip->client,
MAX17042_MinMaxVolt);
val->intval >>= 8;
val->intval *= 20000; /* Units of LSB = 20mV */
break;
case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
val->intval = max17042_read_reg(chip->client,
MAX17042_V_empty);
val->intval >>= 7;
val->intval *= 10000; /* Units of LSB = 10mV */
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = max17042_read_reg(chip->client, MAX17042_VCELL)
* 625 / 8;
break;
case POWER_SUPPLY_PROP_VOLTAGE_AVG:
val->intval = max17042_read_reg(chip->client, MAX17042_AvgVCELL)
* 625 / 8;
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = max17042_read_reg(chip->client,
MAX17042_SOC) / 256;
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
val->intval = max17042_read_reg(chip->client,
MAX17042_RepSOC);
if ((val->intval / 256) >= MAX17042_BATTERY_FULL)
val->intval = 1;
else if (val->intval >= 0)
val->intval = 0;
break;
case POWER_SUPPLY_PROP_TEMP:
val->intval = max17042_read_reg(chip->client,
MAX17042_TEMP);
/* The value is signed. */
if (val->intval & 0x8000) {
val->intval = (0x7fff & ~val->intval) + 1;
val->intval *= -1;
}
/* The value is converted into deci-centigrade scale */
/* Units of LSB = 1 / 256 degree Celsius */
val->intval = val->intval * 10 / 256;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
if (chip->pdata->enable_current_sense) {
val->intval = max17042_read_reg(chip->client,
MAX17042_Current);
if (val->intval & 0x8000) {
/* Negative */
val->intval = ~val->intval & 0x7fff;
val->intval++;
val->intval *= -1;
}
val->intval *= 1562500 / chip->pdata->r_sns;
} else {
return -EINVAL;
}
break;
case POWER_SUPPLY_PROP_CURRENT_AVG:
if (chip->pdata->enable_current_sense) {
val->intval = max17042_read_reg(chip->client,
MAX17042_AvgCurrent);
if (val->intval & 0x8000) {
/* Negative */
val->intval = ~val->intval & 0x7fff;
val->intval++;
val->intval *= -1;
}
val->intval *= 1562500 / chip->pdata->r_sns;
} else {
return -EINVAL;
}
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);
/* When current is not measured,
* CURRENT_NOW and CURRENT_AVG properties should be invisible. */
if (!chip->pdata->enable_current_sense)
chip->battery.num_properties -= 2;
if (chip->pdata->r_sns == 0)
chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
ret = power_supply_register(&client->dev, &chip->battery);
if (ret) {
dev_err(&client->dev, "failed: power supply register\n");
kfree(chip);
return ret;
}
/* Initialize registers according to values from the platform data */
if (chip->pdata->init_data)
max17042_set_reg(client, chip->pdata->init_data,
chip->pdata->num_init_data);
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);
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");
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