2 * BQ27x00 battery driver
4 * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
7 * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
9 * This package is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 #include <linux/module.h>
19 #include <linux/param.h>
20 #include <linux/jiffies.h>
21 #include <linux/workqueue.h>
22 #include <linux/delay.h>
23 #include <linux/platform_device.h>
24 #include <linux/power_supply.h>
25 #include <linux/idr.h>
26 #include <linux/i2c.h>
27 #include <asm/unaligned.h>
29 #define DRIVER_VERSION "1.1.0"
31 #define BQ27x00_REG_TEMP 0x06
32 #define BQ27x00_REG_VOLT 0x08
33 #define BQ27x00_REG_AI 0x14
34 #define BQ27x00_REG_FLAGS 0x0A
35 #define BQ27x00_REG_TTE 0x16
36 #define BQ27x00_REG_TTF 0x18
37 #define BQ27x00_REG_TTECP 0x26
39 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
40 #define BQ27000_FLAG_CHGS BIT(7)
42 #define BQ27500_REG_SOC 0x2c
43 #define BQ27500_FLAG_DSC BIT(0)
44 #define BQ27500_FLAG_FC BIT(9)
46 /* If the system has several batteries we need a different name for each
49 static DEFINE_IDR(battery_id);
50 static DEFINE_MUTEX(battery_mutex);
52 struct bq27x00_device_info;
53 struct bq27x00_access_methods {
54 int (*read)(u8 reg, int *rt_value, int b_single,
55 struct bq27x00_device_info *di);
58 enum bq27x00_chip { BQ27000, BQ27500 };
60 struct bq27x00_device_info {
63 struct bq27x00_access_methods *bus;
64 struct power_supply bat;
65 enum bq27x00_chip chip;
67 struct i2c_client *client;
70 static enum power_supply_property bq27x00_battery_props[] = {
71 POWER_SUPPLY_PROP_STATUS,
72 POWER_SUPPLY_PROP_PRESENT,
73 POWER_SUPPLY_PROP_VOLTAGE_NOW,
74 POWER_SUPPLY_PROP_CURRENT_NOW,
75 POWER_SUPPLY_PROP_CAPACITY,
76 POWER_SUPPLY_PROP_TEMP,
77 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
78 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
79 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
83 * Common code for BQ27x00 devices
86 static int bq27x00_read(u8 reg, int *rt_value, int b_single,
87 struct bq27x00_device_info *di)
89 return di->bus->read(reg, rt_value, b_single, di);
93 * Return the battery temperature in tenths of degree Celsius
94 * Or < 0 if something fails.
96 static int bq27x00_battery_temperature(struct bq27x00_device_info *di)
101 ret = bq27x00_read(BQ27x00_REG_TEMP, &temp, 0, di);
103 dev_err(di->dev, "error reading temperature\n");
107 if (di->chip == BQ27500)
110 return ((temp >> 2) - 273) * 10;
114 * Return the battery Voltage in milivolts
115 * Or < 0 if something fails.
117 static int bq27x00_battery_voltage(struct bq27x00_device_info *di)
122 ret = bq27x00_read(BQ27x00_REG_VOLT, &volt, 0, di);
124 dev_err(di->dev, "error reading voltage\n");
132 * Return the battery average current
133 * Note that current can be negative signed as well
134 * Or 0 if something fails.
136 static int bq27x00_battery_current(struct bq27x00_device_info *di)
142 ret = bq27x00_read(BQ27x00_REG_AI, &curr, 0, di);
144 dev_err(di->dev, "error reading current\n");
148 if (di->chip == BQ27500) {
149 /* bq27500 returns signed value */
150 curr = (int)(s16)curr;
152 ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
154 dev_err(di->dev, "error reading flags\n");
157 if (flags & BQ27000_FLAG_CHGS) {
158 dev_dbg(di->dev, "negative current!\n");
167 * Return the battery Relative State-of-Charge
168 * Or < 0 if something fails.
170 static int bq27x00_battery_rsoc(struct bq27x00_device_info *di)
175 if (di->chip == BQ27500)
176 ret = bq27x00_read(BQ27500_REG_SOC, &rsoc, 0, di);
178 ret = bq27x00_read(BQ27000_REG_RSOC, &rsoc, 1, di);
180 dev_err(di->dev, "error reading relative State-of-Charge\n");
187 static int bq27x00_battery_status(struct bq27x00_device_info *di,
188 union power_supply_propval *val)
194 ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
196 dev_err(di->dev, "error reading flags\n");
200 if (di->chip == BQ27500) {
201 if (flags & BQ27500_FLAG_FC)
202 status = POWER_SUPPLY_STATUS_FULL;
203 else if (flags & BQ27500_FLAG_DSC)
204 status = POWER_SUPPLY_STATUS_DISCHARGING;
206 status = POWER_SUPPLY_STATUS_CHARGING;
208 if (flags & BQ27000_FLAG_CHGS)
209 status = POWER_SUPPLY_STATUS_CHARGING;
211 status = POWER_SUPPLY_STATUS_DISCHARGING;
214 val->intval = status;
219 * Read a time register.
220 * Return < 0 if something fails.
222 static int bq27x00_battery_time(struct bq27x00_device_info *di, int reg,
223 union power_supply_propval *val)
228 ret = bq27x00_read(reg, &tval, 0, di);
230 dev_err(di->dev, "error reading register %02x\n", reg);
237 val->intval = tval * 60;
241 #define to_bq27x00_device_info(x) container_of((x), \
242 struct bq27x00_device_info, bat);
244 static int bq27x00_battery_get_property(struct power_supply *psy,
245 enum power_supply_property psp,
246 union power_supply_propval *val)
249 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
252 case POWER_SUPPLY_PROP_STATUS:
253 ret = bq27x00_battery_status(di, val);
255 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
256 case POWER_SUPPLY_PROP_PRESENT:
257 val->intval = bq27x00_battery_voltage(di);
258 if (psp == POWER_SUPPLY_PROP_PRESENT)
259 val->intval = val->intval <= 0 ? 0 : 1;
261 case POWER_SUPPLY_PROP_CURRENT_NOW:
262 val->intval = bq27x00_battery_current(di);
264 case POWER_SUPPLY_PROP_CAPACITY:
265 val->intval = bq27x00_battery_rsoc(di);
267 case POWER_SUPPLY_PROP_TEMP:
268 val->intval = bq27x00_battery_temperature(di);
270 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
271 ret = bq27x00_battery_time(di, BQ27x00_REG_TTE, val);
273 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
274 ret = bq27x00_battery_time(di, BQ27x00_REG_TTECP, val);
276 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
277 ret = bq27x00_battery_time(di, BQ27x00_REG_TTF, val);
286 static void bq27x00_powersupply_init(struct bq27x00_device_info *di)
288 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
289 di->bat.properties = bq27x00_battery_props;
290 di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
291 di->bat.get_property = bq27x00_battery_get_property;
292 di->bat.external_power_changed = NULL;
299 static int bq27x00_read_i2c(u8 reg, int *rt_value, int b_single,
300 struct bq27x00_device_info *di)
302 struct i2c_client *client = di->client;
303 struct i2c_msg msg[1];
304 unsigned char data[2];
307 if (!client->adapter)
310 msg->addr = client->addr;
316 err = i2c_transfer(client->adapter, msg, 1);
324 msg->flags = I2C_M_RD;
325 err = i2c_transfer(client->adapter, msg, 1);
328 *rt_value = get_unaligned_le16(data);
338 static int bq27x00_battery_probe(struct i2c_client *client,
339 const struct i2c_device_id *id)
342 struct bq27x00_device_info *di;
343 struct bq27x00_access_methods *bus;
347 /* Get new ID for the new battery device */
348 retval = idr_pre_get(&battery_id, GFP_KERNEL);
351 mutex_lock(&battery_mutex);
352 retval = idr_get_new(&battery_id, client, &num);
353 mutex_unlock(&battery_mutex);
357 name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
359 dev_err(&client->dev, "failed to allocate device name\n");
364 di = kzalloc(sizeof(*di), GFP_KERNEL);
366 dev_err(&client->dev, "failed to allocate device info data\n");
371 di->chip = id->driver_data;
373 bus = kzalloc(sizeof(*bus), GFP_KERNEL);
375 dev_err(&client->dev, "failed to allocate access method "
381 i2c_set_clientdata(client, di);
382 di->dev = &client->dev;
384 bus->read = &bq27x00_read_i2c;
388 bq27x00_powersupply_init(di);
390 retval = power_supply_register(&client->dev, &di->bat);
392 dev_err(&client->dev, "failed to register battery\n");
396 dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
407 mutex_lock(&battery_mutex);
408 idr_remove(&battery_id, num);
409 mutex_unlock(&battery_mutex);
414 static int bq27x00_battery_remove(struct i2c_client *client)
416 struct bq27x00_device_info *di = i2c_get_clientdata(client);
418 power_supply_unregister(&di->bat);
422 mutex_lock(&battery_mutex);
423 idr_remove(&battery_id, di->id);
424 mutex_unlock(&battery_mutex);
435 static const struct i2c_device_id bq27x00_id[] = {
436 { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
437 { "bq27500", BQ27500 },
441 static struct i2c_driver bq27x00_battery_driver = {
443 .name = "bq27x00-battery",
445 .probe = bq27x00_battery_probe,
446 .remove = bq27x00_battery_remove,
447 .id_table = bq27x00_id,
450 static int __init bq27x00_battery_init(void)
454 ret = i2c_add_driver(&bq27x00_battery_driver);
456 printk(KERN_ERR "Unable to register BQ27x00 driver\n");
460 module_init(bq27x00_battery_init);
462 static void __exit bq27x00_battery_exit(void)
464 i2c_del_driver(&bq27x00_battery_driver);
466 module_exit(bq27x00_battery_exit);
468 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
469 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
470 MODULE_LICENSE("GPL");