2 * BQ27x00 battery driver
4 * Copyright (C) 2008 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (C) 2008 Eurotech S.p.A. <info@eurotech.it>
6 * Copyright (C) 2010-2011 Lars-Peter Clausen <lars@metafoo.de>
7 * Copyright (C) 2011 Pali Rohár <pali.rohar@gmail.com>
9 * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
11 * This package is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
15 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23 * http://focus.ti.com/docs/prod/folders/print/bq27000.html
24 * http://focus.ti.com/docs/prod/folders/print/bq27500.html
27 #include <linux/module.h>
28 #include <linux/param.h>
29 #include <linux/jiffies.h>
30 #include <linux/workqueue.h>
31 #include <linux/delay.h>
32 #include <linux/platform_device.h>
33 #include <linux/power_supply.h>
34 #include <linux/idr.h>
35 #include <linux/i2c.h>
36 #include <linux/slab.h>
37 #include <asm/unaligned.h>
39 #include <linux/power/bq27x00_battery.h>
41 #define DRIVER_VERSION "1.2.0"
43 #define BQ27x00_REG_TEMP 0x06
44 #define BQ27x00_REG_VOLT 0x08
45 #define BQ27x00_REG_AI 0x14
46 #define BQ27x00_REG_FLAGS 0x0A
47 #define BQ27x00_REG_TTE 0x16
48 #define BQ27x00_REG_TTF 0x18
49 #define BQ27x00_REG_TTECP 0x26
50 #define BQ27x00_REG_NAC 0x0C /* Nominal available capaciy */
51 #define BQ27x00_REG_LMD 0x12 /* Last measured discharge */
52 #define BQ27x00_REG_CYCT 0x2A /* Cycle count total */
53 #define BQ27x00_REG_AE 0x22 /* Available enery */
55 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
56 #define BQ27000_REG_ILMD 0x76 /* Initial last measured discharge */
57 #define BQ27000_FLAG_CHGS BIT(7)
58 #define BQ27000_FLAG_FC BIT(5)
60 #define BQ27500_REG_SOC 0x2C
61 #define BQ27500_REG_DCAP 0x3C /* Design capacity */
62 #define BQ27500_FLAG_DSC BIT(0)
63 #define BQ27500_FLAG_FC BIT(9)
65 #define BQ27000_RS 20 /* Resistor sense */
67 struct bq27x00_device_info;
68 struct bq27x00_access_methods {
69 int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
72 enum bq27x00_chip { BQ27000, BQ27500 };
74 struct bq27x00_reg_cache {
77 int time_to_empty_avg;
87 struct bq27x00_device_info {
90 enum bq27x00_chip chip;
92 struct bq27x00_reg_cache cache;
93 int charge_design_full;
95 unsigned long last_update;
96 struct delayed_work work;
98 struct power_supply bat;
100 struct bq27x00_access_methods bus;
105 static enum power_supply_property bq27x00_battery_props[] = {
106 POWER_SUPPLY_PROP_STATUS,
107 POWER_SUPPLY_PROP_PRESENT,
108 POWER_SUPPLY_PROP_VOLTAGE_NOW,
109 POWER_SUPPLY_PROP_CURRENT_NOW,
110 POWER_SUPPLY_PROP_CAPACITY,
111 POWER_SUPPLY_PROP_TEMP,
112 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
113 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
114 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
115 POWER_SUPPLY_PROP_TECHNOLOGY,
116 POWER_SUPPLY_PROP_CHARGE_FULL,
117 POWER_SUPPLY_PROP_CHARGE_NOW,
118 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
119 POWER_SUPPLY_PROP_CYCLE_COUNT,
120 POWER_SUPPLY_PROP_ENERGY_NOW,
123 static unsigned int poll_interval = 360;
124 module_param(poll_interval, uint, 0644);
125 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
126 "0 disables polling");
129 * Common code for BQ27x00 devices
132 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
135 return di->bus.read(di, reg, single);
139 * Return the battery Relative State-of-Charge
140 * Or < 0 if something fails.
142 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
146 if (di->chip == BQ27500)
147 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
149 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
152 dev_err(di->dev, "error reading relative State-of-Charge\n");
158 * Return a battery charge value in µAh
159 * Or < 0 if something fails.
161 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
165 charge = bq27x00_read(di, reg, false);
167 dev_err(di->dev, "error reading nominal available capacity\n");
171 if (di->chip == BQ27500)
174 charge = charge * 3570 / BQ27000_RS;
180 * Return the battery Nominal available capaciy in µAh
181 * Or < 0 if something fails.
183 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
185 return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
189 * Return the battery Last measured discharge in µAh
190 * Or < 0 if something fails.
192 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
194 return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
198 * Return the battery Initial last measured discharge in µAh
199 * Or < 0 if something fails.
201 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
205 if (di->chip == BQ27500)
206 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
208 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
211 dev_err(di->dev, "error reading initial last measured discharge\n");
215 if (di->chip == BQ27500)
218 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
224 * Return the battery Cycle count total
225 * Or < 0 if something fails.
227 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
231 cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
233 dev_err(di->dev, "error reading cycle count total\n");
239 * Read a time register.
240 * Return < 0 if something fails.
242 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
246 tval = bq27x00_read(di, reg, false);
248 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
258 static void bq27x00_update(struct bq27x00_device_info *di)
260 struct bq27x00_reg_cache cache = {0, };
261 bool is_bq27500 = di->chip == BQ27500;
263 cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
264 if (cache.flags >= 0) {
265 cache.capacity = bq27x00_battery_read_rsoc(di);
266 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
267 cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
268 cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
269 cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
270 cache.charge_full = bq27x00_battery_read_lmd(di);
271 cache.cycle_count = bq27x00_battery_read_cyct(di);
274 cache.current_now = bq27x00_read(di, BQ27x00_REG_AI, false);
276 /* We only have to read charge design full once */
277 if (di->charge_design_full <= 0)
278 di->charge_design_full = bq27x00_battery_read_ilmd(di);
281 /* Ignore current_now which is a snapshot of the current battery state
282 * and is likely to be different even between two consecutive reads */
283 if (memcmp(&di->cache, &cache, sizeof(cache) - sizeof(int)) != 0) {
285 power_supply_changed(&di->bat);
288 di->last_update = jiffies;
291 static void bq27x00_battery_poll(struct work_struct *work)
293 struct bq27x00_device_info *di =
294 container_of(work, struct bq27x00_device_info, work.work);
298 if (poll_interval > 0) {
299 /* The timer does not have to be accurate. */
300 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
301 schedule_delayed_work(&di->work, poll_interval * HZ);
307 * Return the battery temperature in tenths of degree Celsius
308 * Or < 0 if something fails.
310 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
311 union power_supply_propval *val)
313 if (di->cache.temperature < 0)
314 return di->cache.temperature;
316 if (di->chip == BQ27500)
317 val->intval = di->cache.temperature - 2731;
319 val->intval = ((di->cache.temperature * 5) - 5463) / 2;
325 * Return the battery average current in µA
326 * Note that current can be negative signed as well
327 * Or 0 if something fails.
329 static int bq27x00_battery_current(struct bq27x00_device_info *di,
330 union power_supply_propval *val)
334 if (di->chip == BQ27500)
335 curr = bq27x00_read(di, BQ27x00_REG_AI, false);
337 curr = di->cache.current_now;
342 if (di->chip == BQ27500) {
343 /* bq27500 returns signed value */
344 val->intval = (int)((s16)curr) * 1000;
346 if (di->cache.flags & BQ27000_FLAG_CHGS) {
347 dev_dbg(di->dev, "negative current!\n");
351 val->intval = curr * 3570 / BQ27000_RS;
357 static int bq27x00_battery_status(struct bq27x00_device_info *di,
358 union power_supply_propval *val)
362 if (di->chip == BQ27500) {
363 if (di->cache.flags & BQ27500_FLAG_FC)
364 status = POWER_SUPPLY_STATUS_FULL;
365 else if (di->cache.flags & BQ27500_FLAG_DSC)
366 status = POWER_SUPPLY_STATUS_DISCHARGING;
368 status = POWER_SUPPLY_STATUS_CHARGING;
370 if (di->cache.flags & BQ27000_FLAG_FC)
371 status = POWER_SUPPLY_STATUS_FULL;
372 else if (di->cache.flags & BQ27000_FLAG_CHGS)
373 status = POWER_SUPPLY_STATUS_CHARGING;
374 else if (power_supply_am_i_supplied(&di->bat))
375 status = POWER_SUPPLY_STATUS_NOT_CHARGING;
377 status = POWER_SUPPLY_STATUS_DISCHARGING;
380 val->intval = status;
386 * Return the battery Voltage in milivolts
387 * Or < 0 if something fails.
389 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
390 union power_supply_propval *val)
394 volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
398 val->intval = volt * 1000;
404 * Return the battery Available energy in µWh
405 * Or < 0 if something fails.
407 static int bq27x00_battery_energy(struct bq27x00_device_info *di,
408 union power_supply_propval *val)
412 ae = bq27x00_read(di, BQ27x00_REG_AE, false);
414 dev_err(di->dev, "error reading available energy\n");
418 if (di->chip == BQ27500)
421 ae = ae * 29200 / BQ27000_RS;
429 static int bq27x00_simple_value(int value,
430 union power_supply_propval *val)
440 #define to_bq27x00_device_info(x) container_of((x), \
441 struct bq27x00_device_info, bat);
443 static int bq27x00_battery_get_property(struct power_supply *psy,
444 enum power_supply_property psp,
445 union power_supply_propval *val)
448 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
450 mutex_lock(&di->lock);
451 if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
452 cancel_delayed_work_sync(&di->work);
453 bq27x00_battery_poll(&di->work.work);
455 mutex_unlock(&di->lock);
457 if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
461 case POWER_SUPPLY_PROP_STATUS:
462 ret = bq27x00_battery_status(di, val);
464 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
465 ret = bq27x00_battery_voltage(di, val);
467 case POWER_SUPPLY_PROP_PRESENT:
468 val->intval = di->cache.flags < 0 ? 0 : 1;
470 case POWER_SUPPLY_PROP_CURRENT_NOW:
471 ret = bq27x00_battery_current(di, val);
473 case POWER_SUPPLY_PROP_CAPACITY:
474 ret = bq27x00_simple_value(di->cache.capacity, val);
476 case POWER_SUPPLY_PROP_TEMP:
477 ret = bq27x00_battery_temperature(di, val);
479 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
480 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
482 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
483 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
485 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
486 ret = bq27x00_simple_value(di->cache.time_to_full, val);
488 case POWER_SUPPLY_PROP_TECHNOLOGY:
489 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
491 case POWER_SUPPLY_PROP_CHARGE_NOW:
492 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
494 case POWER_SUPPLY_PROP_CHARGE_FULL:
495 ret = bq27x00_simple_value(di->cache.charge_full, val);
497 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
498 ret = bq27x00_simple_value(di->charge_design_full, val);
500 case POWER_SUPPLY_PROP_CYCLE_COUNT:
501 ret = bq27x00_simple_value(di->cache.cycle_count, val);
503 case POWER_SUPPLY_PROP_ENERGY_NOW:
504 ret = bq27x00_battery_energy(di, val);
513 static void bq27x00_external_power_changed(struct power_supply *psy)
515 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
517 cancel_delayed_work_sync(&di->work);
518 schedule_delayed_work(&di->work, 0);
521 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
525 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
526 di->bat.properties = bq27x00_battery_props;
527 di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
528 di->bat.get_property = bq27x00_battery_get_property;
529 di->bat.external_power_changed = bq27x00_external_power_changed;
531 INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
532 mutex_init(&di->lock);
534 ret = power_supply_register(di->dev, &di->bat);
536 dev_err(di->dev, "failed to register battery: %d\n", ret);
540 dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
547 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
549 cancel_delayed_work_sync(&di->work);
551 power_supply_unregister(&di->bat);
553 mutex_destroy(&di->lock);
557 /* i2c specific code */
558 #ifdef CONFIG_BATTERY_BQ27X00_I2C
560 /* If the system has several batteries we need a different name for each
563 static DEFINE_IDR(battery_id);
564 static DEFINE_MUTEX(battery_mutex);
566 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
568 struct i2c_client *client = to_i2c_client(di->dev);
569 struct i2c_msg msg[2];
570 unsigned char data[2];
573 if (!client->adapter)
576 msg[0].addr = client->addr;
579 msg[0].len = sizeof(reg);
580 msg[1].addr = client->addr;
581 msg[1].flags = I2C_M_RD;
588 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
593 ret = get_unaligned_le16(data);
600 static int bq27x00_battery_probe(struct i2c_client *client,
601 const struct i2c_device_id *id)
604 struct bq27x00_device_info *di;
608 /* Get new ID for the new battery device */
609 retval = idr_pre_get(&battery_id, GFP_KERNEL);
612 mutex_lock(&battery_mutex);
613 retval = idr_get_new(&battery_id, client, &num);
614 mutex_unlock(&battery_mutex);
618 name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
620 dev_err(&client->dev, "failed to allocate device name\n");
625 di = kzalloc(sizeof(*di), GFP_KERNEL);
627 dev_err(&client->dev, "failed to allocate device info data\n");
633 di->dev = &client->dev;
634 di->chip = id->driver_data;
636 di->bus.read = &bq27x00_read_i2c;
638 if (bq27x00_powersupply_init(di))
641 i2c_set_clientdata(client, di);
650 mutex_lock(&battery_mutex);
651 idr_remove(&battery_id, num);
652 mutex_unlock(&battery_mutex);
657 static int bq27x00_battery_remove(struct i2c_client *client)
659 struct bq27x00_device_info *di = i2c_get_clientdata(client);
661 bq27x00_powersupply_unregister(di);
665 mutex_lock(&battery_mutex);
666 idr_remove(&battery_id, di->id);
667 mutex_unlock(&battery_mutex);
674 static const struct i2c_device_id bq27x00_id[] = {
675 { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
676 { "bq27500", BQ27500 },
679 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
681 static struct i2c_driver bq27x00_battery_driver = {
683 .name = "bq27x00-battery",
685 .probe = bq27x00_battery_probe,
686 .remove = bq27x00_battery_remove,
687 .id_table = bq27x00_id,
690 static inline int bq27x00_battery_i2c_init(void)
692 int ret = i2c_add_driver(&bq27x00_battery_driver);
694 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
699 static inline void bq27x00_battery_i2c_exit(void)
701 i2c_del_driver(&bq27x00_battery_driver);
706 static inline int bq27x00_battery_i2c_init(void) { return 0; }
707 static inline void bq27x00_battery_i2c_exit(void) {};
711 /* platform specific code */
712 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
714 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
717 struct device *dev = di->dev;
718 struct bq27000_platform_data *pdata = dev->platform_data;
719 unsigned int timeout = 3;
724 /* Make sure the value has not changed in between reading the
725 * lower and the upper part */
726 upper = pdata->read(dev, reg + 1);
732 lower = pdata->read(dev, reg);
736 upper = pdata->read(dev, reg + 1);
737 } while (temp != upper && --timeout);
742 return (upper << 8) | lower;
745 return pdata->read(dev, reg);
748 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
750 struct bq27x00_device_info *di;
751 struct bq27000_platform_data *pdata = pdev->dev.platform_data;
755 dev_err(&pdev->dev, "no platform_data supplied\n");
760 dev_err(&pdev->dev, "no hdq read callback supplied\n");
764 di = kzalloc(sizeof(*di), GFP_KERNEL);
766 dev_err(&pdev->dev, "failed to allocate device info data\n");
770 platform_set_drvdata(pdev, di);
772 di->dev = &pdev->dev;
775 di->bat.name = pdata->name ?: dev_name(&pdev->dev);
776 di->bus.read = &bq27000_read_platform;
778 ret = bq27x00_powersupply_init(di);
785 platform_set_drvdata(pdev, NULL);
791 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
793 struct bq27x00_device_info *di = platform_get_drvdata(pdev);
795 bq27x00_powersupply_unregister(di);
797 platform_set_drvdata(pdev, NULL);
803 static struct platform_driver bq27000_battery_driver = {
804 .probe = bq27000_battery_probe,
805 .remove = __devexit_p(bq27000_battery_remove),
807 .name = "bq27000-battery",
808 .owner = THIS_MODULE,
812 static inline int bq27x00_battery_platform_init(void)
814 int ret = platform_driver_register(&bq27000_battery_driver);
816 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
821 static inline void bq27x00_battery_platform_exit(void)
823 platform_driver_unregister(&bq27000_battery_driver);
828 static inline int bq27x00_battery_platform_init(void) { return 0; }
829 static inline void bq27x00_battery_platform_exit(void) {};
837 static int __init bq27x00_battery_init(void)
841 ret = bq27x00_battery_i2c_init();
845 ret = bq27x00_battery_platform_init();
847 bq27x00_battery_i2c_exit();
851 module_init(bq27x00_battery_init);
853 static void __exit bq27x00_battery_exit(void)
855 bq27x00_battery_platform_exit();
856 bq27x00_battery_i2c_exit();
858 module_exit(bq27x00_battery_exit);
860 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
861 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
862 MODULE_LICENSE("GPL");