/* * 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 * * 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 #include #include #include #include #include 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); int ret; switch (psp) { case POWER_SUPPLY_PROP_PRESENT: ret = max17042_read_reg(chip->client, MAX17042_STATUS); if (ret < 0) return ret; if (ret & MAX17042_STATUS_BattAbsent) val->intval = 0; else val->intval = 1; break; case POWER_SUPPLY_PROP_CYCLE_COUNT: ret = max17042_read_reg(chip->client, MAX17042_Cycles); if (ret < 0) return ret; val->intval = ret; break; case POWER_SUPPLY_PROP_VOLTAGE_MAX: ret = max17042_read_reg(chip->client, MAX17042_MinMaxVolt); if (ret < 0) return ret; val->intval = ret >> 8; val->intval *= 20000; /* Units of LSB = 20mV */ break; case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN: ret = max17042_read_reg(chip->client, MAX17042_V_empty); if (ret < 0) return ret; val->intval = ret >> 7; val->intval *= 10000; /* Units of LSB = 10mV */ break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: ret = max17042_read_reg(chip->client, MAX17042_VCELL); if (ret < 0) return ret; val->intval = ret * 625 / 8; break; case POWER_SUPPLY_PROP_VOLTAGE_AVG: ret = max17042_read_reg(chip->client, MAX17042_AvgVCELL); if (ret < 0) return ret; val->intval = ret * 625 / 8; break; case POWER_SUPPLY_PROP_CAPACITY: ret = max17042_read_reg(chip->client, MAX17042_SOC); if (ret < 0) return ret; val->intval = ret >> 8; break; case POWER_SUPPLY_PROP_CHARGE_FULL: ret = max17042_read_reg(chip->client, MAX17042_RepSOC); if (ret < 0) return ret; if ((ret >> 8) >= MAX17042_BATTERY_FULL) val->intval = 1; else if (ret >= 0) val->intval = 0; break; case POWER_SUPPLY_PROP_TEMP: ret = max17042_read_reg(chip->client, MAX17042_TEMP); if (ret < 0) return ret; val->intval = ret; /* 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) { ret = max17042_read_reg(chip->client, MAX17042_Current); if (ret < 0) return ret; val->intval = ret; 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) { ret = max17042_read_reg(chip->client, MAX17042_AvgCurrent); if (ret < 0) return ret; val->intval = ret; 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 "); MODULE_DESCRIPTION("MAX17042 Fuel Gauge"); MODULE_LICENSE("GPL");