/* * BQ27x00 battery driver * * Copyright (C) 2008 Rodolfo Giometti * Copyright (C) 2008 Eurotech S.p.A. * Copyright (C) 2010-2011 Lars-Peter Clausen * * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc. * * This package 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. * * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * */ /* * Datasheets: * http://focus.ti.com/docs/prod/folders/print/bq27000.html * http://focus.ti.com/docs/prod/folders/print/bq27500.html */ #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_VERSION "1.2.0" #define BQ27x00_REG_TEMP 0x06 #define BQ27x00_REG_VOLT 0x08 #define BQ27x00_REG_AI 0x14 #define BQ27x00_REG_FLAGS 0x0A #define BQ27x00_REG_TTE 0x16 #define BQ27x00_REG_TTF 0x18 #define BQ27x00_REG_TTECP 0x26 #define BQ27x00_REG_NAC 0x0C /* Nominal available capaciy */ #define BQ27x00_REG_LMD 0x12 /* Last measured discharge */ #define BQ27x00_REG_CYCT 0x2A /* Cycle count total */ #define BQ27x00_REG_AE 0x22 /* Available enery */ #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */ #define BQ27000_REG_ILMD 0x76 /* Initial last measured discharge */ #define BQ27000_FLAG_CHGS BIT(7) #define BQ27000_FLAG_FC BIT(5) #define BQ27500_REG_SOC 0x2c #define BQ27500_REG_DCAP 0x3C /* Design capacity */ #define BQ27500_FLAG_DSC BIT(0) #define BQ27500_FLAG_FC BIT(9) #define BQ27000_RS 20 /* Resistor sense */ struct bq27x00_device_info; struct bq27x00_access_methods { int (*read)(struct bq27x00_device_info *di, u8 reg, bool single); }; enum bq27x00_chip { BQ27000, BQ27500 }; struct bq27x00_reg_cache { int temperature; int time_to_empty; int time_to_empty_avg; int time_to_full; int charge_full; int charge_counter; int capacity; int flags; int current_now; }; struct bq27x00_device_info { struct device *dev; int id; enum bq27x00_chip chip; struct bq27x00_reg_cache cache; int charge_design_full; unsigned long last_update; struct delayed_work work; struct power_supply bat; struct bq27x00_access_methods bus; struct mutex lock; }; static enum power_supply_property bq27x00_battery_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_PRESENT, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_CURRENT_NOW, POWER_SUPPLY_PROP_CAPACITY, POWER_SUPPLY_PROP_TEMP, POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG, POWER_SUPPLY_PROP_TIME_TO_FULL_NOW, POWER_SUPPLY_PROP_TECHNOLOGY, POWER_SUPPLY_PROP_CHARGE_FULL, POWER_SUPPLY_PROP_CHARGE_NOW, POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, POWER_SUPPLY_PROP_CHARGE_COUNTER, POWER_SUPPLY_PROP_ENERGY_NOW, }; static unsigned int poll_interval = 360; module_param(poll_interval, uint, 0644); MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \ "0 disables polling"); /* * Common code for BQ27x00 devices */ static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg, bool single) { return di->bus.read(di, reg, single); } /* * Return the battery Relative State-of-Charge * Or < 0 if something fails. */ static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di) { int rsoc; if (di->chip == BQ27500) rsoc = bq27x00_read(di, BQ27500_REG_SOC, false); else rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true); if (rsoc < 0) dev_err(di->dev, "error reading relative State-of-Charge\n"); return rsoc; } /* * Return a battery charge value in µAh * Or < 0 if something fails. */ static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg) { int charge; charge = bq27x00_read(di, reg, false); if (charge < 0) { dev_err(di->dev, "error reading nominal available capacity\n"); return charge; } if (di->chip == BQ27500) charge *= 1000; else charge = charge * 3570 / BQ27000_RS; return charge; } /* * Return the battery Nominal available capaciy in µAh * Or < 0 if something fails. */ static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di) { return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC); } /* * Return the battery Last measured discharge in µAh * Or < 0 if something fails. */ static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di) { return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD); } /* * Return the battery Initial last measured discharge in µAh * Or < 0 if something fails. */ static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di) { int ilmd; if (di->chip == BQ27500) ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false); else ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true); if (ilmd < 0) { dev_err(di->dev, "error reading initial last measured discharge\n"); return ilmd; } if (di->chip == BQ27500) ilmd *= 1000; else ilmd = ilmd * 256 * 3570 / BQ27000_RS; return ilmd; } /* * Return the battery Cycle count total * Or < 0 if something fails. */ static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di) { int cyct; cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false); if (cyct < 0) dev_err(di->dev, "error reading cycle count total\n"); return cyct; } /* * Read a time register. * Return < 0 if something fails. */ static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg) { int tval; tval = bq27x00_read(di, reg, false); if (tval < 0) { dev_err(di->dev, "error reading register %02x: %d\n", reg, tval); return tval; } if (tval == 65535) return -ENODATA; return tval * 60; } static void bq27x00_update(struct bq27x00_device_info *di) { struct bq27x00_reg_cache cache = {0, }; bool is_bq27500 = di->chip == BQ27500; cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500); if (cache.flags >= 0) { cache.capacity = bq27x00_battery_read_rsoc(di); cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false); cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE); cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP); cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF); cache.charge_full = bq27x00_battery_read_lmd(di); cache.charge_counter = bq27x00_battery_read_cyct(di); if (!is_bq27500) cache.current_now = bq27x00_read(di, BQ27x00_REG_AI, false); /* We only have to read charge design full once */ if (di->charge_design_full <= 0) di->charge_design_full = bq27x00_battery_read_ilmd(di); } /* Ignore current_now which is a snapshot of the current battery state * and is likely to be different even between two consecutive reads */ if (memcmp(&di->cache, &cache, sizeof(cache) - sizeof(int)) != 0) { di->cache = cache; power_supply_changed(&di->bat); } di->last_update = jiffies; } static void bq27x00_battery_poll(struct work_struct *work) { struct bq27x00_device_info *di = container_of(work, struct bq27x00_device_info, work.work); bq27x00_update(di); if (poll_interval > 0) { /* The timer does not have to be accurate. */ set_timer_slack(&di->work.timer, poll_interval * HZ / 4); schedule_delayed_work(&di->work, poll_interval * HZ); } } /* * Return the battery temperature in tenths of degree Celsius * Or < 0 if something fails. */ static int bq27x00_battery_temperature(struct bq27x00_device_info *di, union power_supply_propval *val) { if (di->cache.temperature < 0) return di->cache.temperature; if (di->chip == BQ27500) val->intval = di->cache.temperature - 2731; else val->intval = ((di->cache.temperature * 5) - 5463) / 2; return 0; } /* * Return the battery average current * Note that current can be negative signed as well * Or 0 if something fails. */ static int bq27x00_battery_current(struct bq27x00_device_info *di, union power_supply_propval *val) { int curr; if (di->chip == BQ27500) curr = bq27x00_read(di, BQ27x00_REG_AI, false); else curr = di->cache.current_now; if (curr < 0) return curr; if (di->chip == BQ27500) { /* bq27500 returns signed value */ val->intval = (int)((s16)curr) * 1000; } else { if (di->cache.flags & BQ27000_FLAG_CHGS) { dev_dbg(di->dev, "negative current!\n"); curr = -curr; } val->intval = curr * 3570 / BQ27000_RS; } return 0; } static int bq27x00_battery_status(struct bq27x00_device_info *di, union power_supply_propval *val) { int status; if (di->chip == BQ27500) { if (di->cache.flags & BQ27500_FLAG_FC) status = POWER_SUPPLY_STATUS_FULL; else if (di->cache.flags & BQ27500_FLAG_DSC) status = POWER_SUPPLY_STATUS_DISCHARGING; else status = POWER_SUPPLY_STATUS_CHARGING; } else { if (di->cache.flags & BQ27000_FLAG_FC) status = POWER_SUPPLY_STATUS_FULL; else if (di->cache.flags & BQ27000_FLAG_CHGS) status = POWER_SUPPLY_STATUS_CHARGING; else if (power_supply_am_i_supplied(&di->bat)) status = POWER_SUPPLY_STATUS_NOT_CHARGING; else status = POWER_SUPPLY_STATUS_DISCHARGING; } val->intval = status; return 0; } /* * Return the battery Voltage in milivolts * Or < 0 if something fails. */ static int bq27x00_battery_voltage(struct bq27x00_device_info *di, union power_supply_propval *val) { int volt; volt = bq27x00_read(di, BQ27x00_REG_VOLT, false); if (volt < 0) return volt; val->intval = volt * 1000; return 0; } /* * Return the battery Available energy in µWh * Or < 0 if something fails. */ static int bq27x00_battery_energy(struct bq27x00_device_info *di, union power_supply_propval *val) { int ae; ae = bq27x00_read(di, BQ27x00_REG_AE, false); if (ae < 0) { dev_err(di->dev, "error reading available energy\n"); return ae; } if (di->chip == BQ27500) ae *= 1000; else ae = ae * 29200 / BQ27000_RS; val->intval = ae; return 0; } static int bq27x00_simple_value(int value, union power_supply_propval *val) { if (value < 0) return value; val->intval = value; return 0; } #define to_bq27x00_device_info(x) container_of((x), \ struct bq27x00_device_info, bat); static int bq27x00_battery_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { int ret = 0; struct bq27x00_device_info *di = to_bq27x00_device_info(psy); mutex_lock(&di->lock); if (time_is_before_jiffies(di->last_update + 5 * HZ)) { cancel_delayed_work_sync(&di->work); bq27x00_battery_poll(&di->work.work); } mutex_unlock(&di->lock); if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0) return -ENODEV; switch (psp) { case POWER_SUPPLY_PROP_STATUS: ret = bq27x00_battery_status(di, val); break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: ret = bq27x00_battery_voltage(di, val); break; case POWER_SUPPLY_PROP_PRESENT: val->intval = di->cache.flags < 0 ? 0 : 1; break; case POWER_SUPPLY_PROP_CURRENT_NOW: ret = bq27x00_battery_current(di, val); break; case POWER_SUPPLY_PROP_CAPACITY: ret = bq27x00_simple_value(di->cache.capacity, val); break; case POWER_SUPPLY_PROP_TEMP: ret = bq27x00_battery_temperature(di, val); break; case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: ret = bq27x00_simple_value(di->cache.time_to_empty, val); break; case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG: ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val); break; case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW: ret = bq27x00_simple_value(di->cache.time_to_full, val); break; case POWER_SUPPLY_PROP_TECHNOLOGY: val->intval = POWER_SUPPLY_TECHNOLOGY_LION; break; case POWER_SUPPLY_PROP_CHARGE_NOW: ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val); break; case POWER_SUPPLY_PROP_CHARGE_FULL: ret = bq27x00_simple_value(di->cache.charge_full, val); break; case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: ret = bq27x00_simple_value(di->charge_design_full, val); break; case POWER_SUPPLY_PROP_CHARGE_COUNTER: ret = bq27x00_simple_value(di->cache.charge_counter, val); break; case POWER_SUPPLY_PROP_ENERGY_NOW: ret = bq27x00_battery_energy(di, val); break; default: return -EINVAL; } return ret; } static void bq27x00_external_power_changed(struct power_supply *psy) { struct bq27x00_device_info *di = to_bq27x00_device_info(psy); cancel_delayed_work_sync(&di->work); schedule_delayed_work(&di->work, 0); } static int bq27x00_powersupply_init(struct bq27x00_device_info *di) { int ret; di->bat.type = POWER_SUPPLY_TYPE_BATTERY; di->bat.properties = bq27x00_battery_props; di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props); di->bat.get_property = bq27x00_battery_get_property; di->bat.external_power_changed = bq27x00_external_power_changed; INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll); mutex_init(&di->lock); ret = power_supply_register(di->dev, &di->bat); if (ret) { dev_err(di->dev, "failed to register battery: %d\n", ret); return ret; } dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION); bq27x00_update(di); return 0; } static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di) { cancel_delayed_work_sync(&di->work); power_supply_unregister(&di->bat); mutex_destroy(&di->lock); } /* i2c specific code */ #ifdef CONFIG_BATTERY_BQ27X00_I2C /* If the system has several batteries we need a different name for each * of them... */ static DEFINE_IDR(battery_id); static DEFINE_MUTEX(battery_mutex); static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single) { struct i2c_client *client = to_i2c_client(di->dev); struct i2c_msg msg[1]; unsigned char data[2]; int ret; if (!client->adapter) return -ENODEV; msg->addr = client->addr; msg->flags = 0; msg->len = 1; msg->buf = data; data[0] = reg; ret = i2c_transfer(client->adapter, msg, 1); if (ret >= 0) { if (!single) msg->len = 2; else msg->len = 1; msg->flags = I2C_M_RD; ret = i2c_transfer(client->adapter, msg, 1); if (ret >= 0) { if (!single) ret = get_unaligned_le16(data); else ret = data[0]; } } return ret; } static int bq27x00_battery_probe(struct i2c_client *client, const struct i2c_device_id *id) { char *name; struct bq27x00_device_info *di; int num; int retval = 0; /* Get new ID for the new battery device */ retval = idr_pre_get(&battery_id, GFP_KERNEL); if (retval == 0) return -ENOMEM; mutex_lock(&battery_mutex); retval = idr_get_new(&battery_id, client, &num); mutex_unlock(&battery_mutex); if (retval < 0) return retval; name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num); if (!name) { dev_err(&client->dev, "failed to allocate device name\n"); retval = -ENOMEM; goto batt_failed_1; } di = kzalloc(sizeof(*di), GFP_KERNEL); if (!di) { dev_err(&client->dev, "failed to allocate device info data\n"); retval = -ENOMEM; goto batt_failed_2; } di->id = num; di->dev = &client->dev; di->chip = id->driver_data; di->bat.name = name; di->bus.read = &bq27x00_read_i2c; if (bq27x00_powersupply_init(di)) goto batt_failed_3; i2c_set_clientdata(client, di); return 0; batt_failed_3: kfree(di); batt_failed_2: kfree(name); batt_failed_1: mutex_lock(&battery_mutex); idr_remove(&battery_id, num); mutex_unlock(&battery_mutex); return retval; } static int bq27x00_battery_remove(struct i2c_client *client) { struct bq27x00_device_info *di = i2c_get_clientdata(client); bq27x00_powersupply_unregister(di); kfree(di->bat.name); mutex_lock(&battery_mutex); idr_remove(&battery_id, di->id); mutex_unlock(&battery_mutex); kfree(di); return 0; } static const struct i2c_device_id bq27x00_id[] = { { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */ { "bq27500", BQ27500 }, {}, }; MODULE_DEVICE_TABLE(i2c, bq27x00_id); static struct i2c_driver bq27x00_battery_driver = { .driver = { .name = "bq27x00-battery", }, .probe = bq27x00_battery_probe, .remove = bq27x00_battery_remove, .id_table = bq27x00_id, }; static inline int bq27x00_battery_i2c_init(void) { int ret = i2c_add_driver(&bq27x00_battery_driver); if (ret) printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n"); return ret; } static inline void bq27x00_battery_i2c_exit(void) { i2c_del_driver(&bq27x00_battery_driver); } #else static inline int bq27x00_battery_i2c_init(void) { return 0; } static inline void bq27x00_battery_i2c_exit(void) {}; #endif /* platform specific code */ #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg, bool single) { struct device *dev = di->dev; struct bq27000_platform_data *pdata = dev->platform_data; unsigned int timeout = 3; int upper, lower; int temp; if (!single) { /* Make sure the value has not changed in between reading the * lower and the upper part */ upper = pdata->read(dev, reg + 1); do { temp = upper; if (upper < 0) return upper; lower = pdata->read(dev, reg); if (lower < 0) return lower; upper = pdata->read(dev, reg + 1); } while (temp != upper && --timeout); if (timeout == 0) return -EIO; return (upper << 8) | lower; } return pdata->read(dev, reg); } static int __devinit bq27000_battery_probe(struct platform_device *pdev) { struct bq27x00_device_info *di; struct bq27000_platform_data *pdata = pdev->dev.platform_data; int ret; if (!pdata) { dev_err(&pdev->dev, "no platform_data supplied\n"); return -EINVAL; } if (!pdata->read) { dev_err(&pdev->dev, "no hdq read callback supplied\n"); return -EINVAL; } di = kzalloc(sizeof(*di), GFP_KERNEL); if (!di) { dev_err(&pdev->dev, "failed to allocate device info data\n"); return -ENOMEM; } platform_set_drvdata(pdev, di); di->dev = &pdev->dev; di->chip = BQ27000; di->bat.name = pdata->name ?: dev_name(&pdev->dev); di->bus.read = &bq27000_read_platform; ret = bq27x00_powersupply_init(di); if (ret) goto err_free; return 0; err_free: platform_set_drvdata(pdev, NULL); kfree(di); return ret; } static int __devexit bq27000_battery_remove(struct platform_device *pdev) { struct bq27x00_device_info *di = platform_get_drvdata(pdev); bq27x00_powersupply_unregister(di); platform_set_drvdata(pdev, NULL); kfree(di); return 0; } static struct platform_driver bq27000_battery_driver = { .probe = bq27000_battery_probe, .remove = __devexit_p(bq27000_battery_remove), .driver = { .name = "bq27000-battery", .owner = THIS_MODULE, }, }; static inline int bq27x00_battery_platform_init(void) { int ret = platform_driver_register(&bq27000_battery_driver); if (ret) printk(KERN_ERR "Unable to register BQ27000 platform driver\n"); return ret; } static inline void bq27x00_battery_platform_exit(void) { platform_driver_unregister(&bq27000_battery_driver); } #else static inline int bq27x00_battery_platform_init(void) { return 0; } static inline void bq27x00_battery_platform_exit(void) {}; #endif /* * Module stuff */ static int __init bq27x00_battery_init(void) { int ret; ret = bq27x00_battery_i2c_init(); if (ret) return ret; ret = bq27x00_battery_platform_init(); if (ret) bq27x00_battery_i2c_exit(); return ret; } module_init(bq27x00_battery_init); static void __exit bq27x00_battery_exit(void) { bq27x00_battery_platform_exit(); bq27x00_battery_i2c_exit(); } module_exit(bq27x00_battery_exit); MODULE_AUTHOR("Rodolfo Giometti "); MODULE_DESCRIPTION("BQ27x00 battery monitor driver"); MODULE_LICENSE("GPL");