/* * max17040_battery.c * fuel-gauge systems for lithium-ion (Li+) batteries * * Copyright (C) 2009 Samsung Electronics * Minkyu Kang <mk7.kang@samsung.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/module.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/mutex.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/delay.h> #include <linux/power_supply.h> #include <linux/max17040_battery.h> #define MAX17040_VCELL_MSB 0x02 #define MAX17040_VCELL_LSB 0x03 #define MAX17040_SOC_MSB 0x04 #define MAX17040_SOC_LSB 0x05 #define MAX17040_MODE_MSB 0x06 #define MAX17040_MODE_LSB 0x07 #define MAX17040_VER_MSB 0x08 #define MAX17040_VER_LSB 0x09 #define MAX17040_RCOMP_MSB 0x0C #define MAX17040_RCOMP_LSB 0x0D #define MAX17040_CMD_MSB 0xFE #define MAX17040_CMD_LSB 0xFF #define MAX17040_DELAY 1000 #define MAX17040_BATTERY_FULL 95 struct max17040_chip { struct i2c_client *client; struct delayed_work work; struct power_supply battery; struct max17040_platform_data *pdata; /* State Of Connect */ int online; /* battery voltage */ int vcell; /* battery capacity */ int soc; /* State Of Charge */ int status; }; static int max17040_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { struct max17040_chip *chip = container_of(psy, struct max17040_chip, battery); switch (psp) { case POWER_SUPPLY_PROP_STATUS: val->intval = chip->status; break; case POWER_SUPPLY_PROP_ONLINE: val->intval = chip->online; break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: val->intval = chip->vcell; break; case POWER_SUPPLY_PROP_CAPACITY: val->intval = chip->soc; break; default: return -EINVAL; } return 0; } static int max17040_write_reg(struct i2c_client *client, int reg, u8 value) { int ret; ret = i2c_smbus_write_byte_data(client, reg, value); if (ret < 0) dev_err(&client->dev, "%s: err %d\n", __func__, ret); return ret; } static int max17040_read_reg(struct i2c_client *client, int reg) { int ret; ret = i2c_smbus_read_byte_data(client, reg); if (ret < 0) dev_err(&client->dev, "%s: err %d\n", __func__, ret); return ret; } static void max17040_reset(struct i2c_client *client) { max17040_write_reg(client, MAX17040_CMD_MSB, 0x54); max17040_write_reg(client, MAX17040_CMD_LSB, 0x00); } static void max17040_get_vcell(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); u8 msb; u8 lsb; msb = max17040_read_reg(client, MAX17040_VCELL_MSB); lsb = max17040_read_reg(client, MAX17040_VCELL_LSB); chip->vcell = (msb << 4) + (lsb >> 4); } static void max17040_get_soc(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); u8 msb; u8 lsb; msb = max17040_read_reg(client, MAX17040_SOC_MSB); lsb = max17040_read_reg(client, MAX17040_SOC_LSB); chip->soc = msb; } static void max17040_get_version(struct i2c_client *client) { u8 msb; u8 lsb; msb = max17040_read_reg(client, MAX17040_VER_MSB); lsb = max17040_read_reg(client, MAX17040_VER_LSB); dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver %d%d\n", msb, lsb); } static void max17040_get_online(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); if (chip->pdata->battery_online) chip->online = chip->pdata->battery_online(); else chip->online = 1; } static void max17040_get_status(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); if (!chip->pdata->charger_online || !chip->pdata->charger_enable) { chip->status = POWER_SUPPLY_STATUS_UNKNOWN; return; } if (chip->pdata->charger_online()) { if (chip->pdata->charger_enable()) chip->status = POWER_SUPPLY_STATUS_CHARGING; else chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING; } else { chip->status = POWER_SUPPLY_STATUS_DISCHARGING; } if (chip->soc > MAX17040_BATTERY_FULL) chip->status = POWER_SUPPLY_STATUS_FULL; } static void max17040_work(struct work_struct *work) { struct max17040_chip *chip; chip = container_of(work, struct max17040_chip, work.work); max17040_get_vcell(chip->client); max17040_get_soc(chip->client); max17040_get_online(chip->client); max17040_get_status(chip->client); schedule_delayed_work(&chip->work, MAX17040_DELAY); } static enum power_supply_property max17040_battery_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_ONLINE, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_CAPACITY, }; static int __devinit max17040_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); struct max17040_chip *chip; int ret; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 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 = "battery"; chip->battery.type = POWER_SUPPLY_TYPE_BATTERY; chip->battery.get_property = max17040_get_property; chip->battery.properties = max17040_battery_props; chip->battery.num_properties = ARRAY_SIZE(max17040_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; } max17040_reset(client); max17040_get_version(client); INIT_DELAYED_WORK_DEFERRABLE(&chip->work, max17040_work); schedule_delayed_work(&chip->work, MAX17040_DELAY); return 0; } static int __devexit max17040_remove(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); power_supply_unregister(&chip->battery); cancel_delayed_work(&chip->work); i2c_set_clientdata(client, NULL); kfree(chip); return 0; } #ifdef CONFIG_PM static int max17040_suspend(struct i2c_client *client, pm_message_t state) { struct max17040_chip *chip = i2c_get_clientdata(client); cancel_delayed_work(&chip->work); return 0; } static int max17040_resume(struct i2c_client *client) { struct max17040_chip *chip = i2c_get_clientdata(client); schedule_delayed_work(&chip->work, MAX17040_DELAY); return 0; } #else #define max17040_suspend NULL #define max17040_resume NULL #endif /* CONFIG_PM */ static const struct i2c_device_id max17040_id[] = { { "max17040", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, max17040_id); static struct i2c_driver max17040_i2c_driver = { .driver = { .name = "max17040", }, .probe = max17040_probe, .remove = __devexit_p(max17040_remove), .suspend = max17040_suspend, .resume = max17040_resume, .id_table = max17040_id, }; static int __init max17040_init(void) { return i2c_add_driver(&max17040_i2c_driver); } module_init(max17040_init); static void __exit max17040_exit(void) { i2c_del_driver(&max17040_i2c_driver); } module_exit(max17040_exit); MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); MODULE_DESCRIPTION("MAX17040 Fuel Gauge"); MODULE_LICENSE("GPL");