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1 /*
2 * BQ27x00 battery driver
3 *
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 *
8 * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
9 *
10 * This package is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
17 *
18 */
19
20 /*
21 * Datasheets:
22 * http://focus.ti.com/docs/prod/folders/print/bq27000.html
23 * http://focus.ti.com/docs/prod/folders/print/bq27500.html
24 */
25
26 #include <linux/module.h>
27 #include <linux/param.h>
28 #include <linux/jiffies.h>
29 #include <linux/workqueue.h>
30 #include <linux/delay.h>
31 #include <linux/platform_device.h>
32 #include <linux/power_supply.h>
33 #include <linux/idr.h>
34 #include <linux/i2c.h>
35 #include <linux/slab.h>
36 #include <asm/unaligned.h>
37
38 #include <linux/power/bq27x00_battery.h>
39
40 #define DRIVER_VERSION "1.2.0"
41
42 #define BQ27x00_REG_TEMP 0x06
43 #define BQ27x00_REG_VOLT 0x08
44 #define BQ27x00_REG_AI 0x14
45 #define BQ27x00_REG_FLAGS 0x0A
46 #define BQ27x00_REG_TTE 0x16
47 #define BQ27x00_REG_TTF 0x18
48 #define BQ27x00_REG_TTECP 0x26
49 #define BQ27x00_REG_NAC 0x0C /* Nominal available capaciy */
50 #define BQ27x00_REG_LMD 0x12 /* Last measured discharge */
51 #define BQ27x00_REG_CYCT 0x2A /* Cycle count total */
52 #define BQ27x00_REG_AE 0x22 /* Available enery */
53
54 #define BQ27000_REG_RSOC 0x0B /* Relative State-of-Charge */
55 #define BQ27000_REG_ILMD 0x76 /* Initial last measured discharge */
56 #define BQ27000_FLAG_CHGS BIT(7)
57 #define BQ27000_FLAG_FC BIT(5)
58
59 #define BQ27500_REG_SOC 0x2C
60 #define BQ27500_REG_DCAP 0x3C /* Design capacity */
61 #define BQ27500_FLAG_DSC BIT(0)
62 #define BQ27500_FLAG_FC BIT(9)
63
64 #define BQ27000_RS 20 /* Resistor sense */
65
66 struct bq27x00_device_info;
67 struct bq27x00_access_methods {
68 int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
69 };
70
71 enum bq27x00_chip { BQ27000, BQ27500 };
72
73 struct bq27x00_reg_cache {
74 int temperature;
75 int time_to_empty;
76 int time_to_empty_avg;
77 int time_to_full;
78 int charge_full;
79 int charge_counter;
80 int capacity;
81 int flags;
82
83 int current_now;
84 };
85
86 struct bq27x00_device_info {
87 struct device *dev;
88 int id;
89 enum bq27x00_chip chip;
90
91 struct bq27x00_reg_cache cache;
92 int charge_design_full;
93
94 unsigned long last_update;
95 struct delayed_work work;
96
97 struct power_supply bat;
98
99 struct bq27x00_access_methods bus;
100
101 struct mutex lock;
102 };
103
104 static enum power_supply_property bq27x00_battery_props[] = {
105 POWER_SUPPLY_PROP_STATUS,
106 POWER_SUPPLY_PROP_PRESENT,
107 POWER_SUPPLY_PROP_VOLTAGE_NOW,
108 POWER_SUPPLY_PROP_CURRENT_NOW,
109 POWER_SUPPLY_PROP_CAPACITY,
110 POWER_SUPPLY_PROP_TEMP,
111 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
112 POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
113 POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
114 POWER_SUPPLY_PROP_TECHNOLOGY,
115 POWER_SUPPLY_PROP_CHARGE_FULL,
116 POWER_SUPPLY_PROP_CHARGE_NOW,
117 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
118 POWER_SUPPLY_PROP_CHARGE_COUNTER,
119 POWER_SUPPLY_PROP_ENERGY_NOW,
120 };
121
122 static unsigned int poll_interval = 360;
123 module_param(poll_interval, uint, 0644);
124 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
125 "0 disables polling");
126
127 /*
128 * Common code for BQ27x00 devices
129 */
130
131 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
132 bool single)
133 {
134 return di->bus.read(di, reg, single);
135 }
136
137 /*
138 * Return the battery Relative State-of-Charge
139 * Or < 0 if something fails.
140 */
141 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
142 {
143 int rsoc;
144
145 if (di->chip == BQ27500)
146 rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
147 else
148 rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
149
150 if (rsoc < 0)
151 dev_err(di->dev, "error reading relative State-of-Charge\n");
152
153 return rsoc;
154 }
155
156 /*
157 * Return a battery charge value in µAh
158 * Or < 0 if something fails.
159 */
160 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
161 {
162 int charge;
163
164 charge = bq27x00_read(di, reg, false);
165 if (charge < 0) {
166 dev_err(di->dev, "error reading nominal available capacity\n");
167 return charge;
168 }
169
170 if (di->chip == BQ27500)
171 charge *= 1000;
172 else
173 charge = charge * 3570 / BQ27000_RS;
174
175 return charge;
176 }
177
178 /*
179 * Return the battery Nominal available capaciy in µAh
180 * Or < 0 if something fails.
181 */
182 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
183 {
184 return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
185 }
186
187 /*
188 * Return the battery Last measured discharge in µAh
189 * Or < 0 if something fails.
190 */
191 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
192 {
193 return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
194 }
195
196 /*
197 * Return the battery Initial last measured discharge in µAh
198 * Or < 0 if something fails.
199 */
200 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
201 {
202 int ilmd;
203
204 if (di->chip == BQ27500)
205 ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
206 else
207 ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
208
209 if (ilmd < 0) {
210 dev_err(di->dev, "error reading initial last measured discharge\n");
211 return ilmd;
212 }
213
214 if (di->chip == BQ27500)
215 ilmd *= 1000;
216 else
217 ilmd = ilmd * 256 * 3570 / BQ27000_RS;
218
219 return ilmd;
220 }
221
222 /*
223 * Return the battery Cycle count total
224 * Or < 0 if something fails.
225 */
226 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
227 {
228 int cyct;
229
230 cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
231 if (cyct < 0)
232 dev_err(di->dev, "error reading cycle count total\n");
233
234 return cyct;
235 }
236
237 /*
238 * Read a time register.
239 * Return < 0 if something fails.
240 */
241 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
242 {
243 int tval;
244
245 tval = bq27x00_read(di, reg, false);
246 if (tval < 0) {
247 dev_err(di->dev, "error reading register %02x: %d\n", reg, tval);
248 return tval;
249 }
250
251 if (tval == 65535)
252 return -ENODATA;
253
254 return tval * 60;
255 }
256
257 static void bq27x00_update(struct bq27x00_device_info *di)
258 {
259 struct bq27x00_reg_cache cache = {0, };
260 bool is_bq27500 = di->chip == BQ27500;
261
262 cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, is_bq27500);
263 if (cache.flags >= 0) {
264 cache.capacity = bq27x00_battery_read_rsoc(di);
265 cache.temperature = bq27x00_read(di, BQ27x00_REG_TEMP, false);
266 cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
267 cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
268 cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
269 cache.charge_full = bq27x00_battery_read_lmd(di);
270 cache.charge_counter = bq27x00_battery_read_cyct(di);
271
272 if (!is_bq27500)
273 cache.current_now = bq27x00_read(di, BQ27x00_REG_AI, false);
274
275 /* We only have to read charge design full once */
276 if (di->charge_design_full <= 0)
277 di->charge_design_full = bq27x00_battery_read_ilmd(di);
278 }
279
280 /* Ignore current_now which is a snapshot of the current battery state
281 * and is likely to be different even between two consecutive reads */
282 if (memcmp(&di->cache, &cache, sizeof(cache) - sizeof(int)) != 0) {
283 di->cache = cache;
284 power_supply_changed(&di->bat);
285 }
286
287 di->last_update = jiffies;
288 }
289
290 static void bq27x00_battery_poll(struct work_struct *work)
291 {
292 struct bq27x00_device_info *di =
293 container_of(work, struct bq27x00_device_info, work.work);
294
295 bq27x00_update(di);
296
297 if (poll_interval > 0) {
298 /* The timer does not have to be accurate. */
299 set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
300 schedule_delayed_work(&di->work, poll_interval * HZ);
301 }
302 }
303
304
305 /*
306 * Return the battery temperature in tenths of degree Celsius
307 * Or < 0 if something fails.
308 */
309 static int bq27x00_battery_temperature(struct bq27x00_device_info *di,
310 union power_supply_propval *val)
311 {
312 if (di->cache.temperature < 0)
313 return di->cache.temperature;
314
315 if (di->chip == BQ27500)
316 val->intval = di->cache.temperature - 2731;
317 else
318 val->intval = ((di->cache.temperature * 5) - 5463) / 2;
319
320 return 0;
321 }
322
323 /*
324 * Return the battery average current in µA
325 * Note that current can be negative signed as well
326 * Or 0 if something fails.
327 */
328 static int bq27x00_battery_current(struct bq27x00_device_info *di,
329 union power_supply_propval *val)
330 {
331 int curr;
332
333 if (di->chip == BQ27500)
334 curr = bq27x00_read(di, BQ27x00_REG_AI, false);
335 else
336 curr = di->cache.current_now;
337
338 if (curr < 0)
339 return curr;
340
341 if (di->chip == BQ27500) {
342 /* bq27500 returns signed value */
343 val->intval = (int)((s16)curr) * 1000;
344 } else {
345 if (di->cache.flags & BQ27000_FLAG_CHGS) {
346 dev_dbg(di->dev, "negative current!\n");
347 curr = -curr;
348 }
349
350 val->intval = curr * 3570 / BQ27000_RS;
351 }
352
353 return 0;
354 }
355
356 static int bq27x00_battery_status(struct bq27x00_device_info *di,
357 union power_supply_propval *val)
358 {
359 int status;
360
361 if (di->chip == BQ27500) {
362 if (di->cache.flags & BQ27500_FLAG_FC)
363 status = POWER_SUPPLY_STATUS_FULL;
364 else if (di->cache.flags & BQ27500_FLAG_DSC)
365 status = POWER_SUPPLY_STATUS_DISCHARGING;
366 else
367 status = POWER_SUPPLY_STATUS_CHARGING;
368 } else {
369 if (di->cache.flags & BQ27000_FLAG_FC)
370 status = POWER_SUPPLY_STATUS_FULL;
371 else if (di->cache.flags & BQ27000_FLAG_CHGS)
372 status = POWER_SUPPLY_STATUS_CHARGING;
373 else if (power_supply_am_i_supplied(&di->bat))
374 status = POWER_SUPPLY_STATUS_NOT_CHARGING;
375 else
376 status = POWER_SUPPLY_STATUS_DISCHARGING;
377 }
378
379 val->intval = status;
380
381 return 0;
382 }
383
384 /*
385 * Return the battery Voltage in milivolts
386 * Or < 0 if something fails.
387 */
388 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
389 union power_supply_propval *val)
390 {
391 int volt;
392
393 volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
394 if (volt < 0)
395 return volt;
396
397 val->intval = volt * 1000;
398
399 return 0;
400 }
401
402 /*
403 * Return the battery Available energy in µWh
404 * Or < 0 if something fails.
405 */
406 static int bq27x00_battery_energy(struct bq27x00_device_info *di,
407 union power_supply_propval *val)
408 {
409 int ae;
410
411 ae = bq27x00_read(di, BQ27x00_REG_AE, false);
412 if (ae < 0) {
413 dev_err(di->dev, "error reading available energy\n");
414 return ae;
415 }
416
417 if (di->chip == BQ27500)
418 ae *= 1000;
419 else
420 ae = ae * 29200 / BQ27000_RS;
421
422 val->intval = ae;
423
424 return 0;
425 }
426
427
428 static int bq27x00_simple_value(int value,
429 union power_supply_propval *val)
430 {
431 if (value < 0)
432 return value;
433
434 val->intval = value;
435
436 return 0;
437 }
438
439 #define to_bq27x00_device_info(x) container_of((x), \
440 struct bq27x00_device_info, bat);
441
442 static int bq27x00_battery_get_property(struct power_supply *psy,
443 enum power_supply_property psp,
444 union power_supply_propval *val)
445 {
446 int ret = 0;
447 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
448
449 mutex_lock(&di->lock);
450 if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
451 cancel_delayed_work_sync(&di->work);
452 bq27x00_battery_poll(&di->work.work);
453 }
454 mutex_unlock(&di->lock);
455
456 if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
457 return -ENODEV;
458
459 switch (psp) {
460 case POWER_SUPPLY_PROP_STATUS:
461 ret = bq27x00_battery_status(di, val);
462 break;
463 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
464 ret = bq27x00_battery_voltage(di, val);
465 break;
466 case POWER_SUPPLY_PROP_PRESENT:
467 val->intval = di->cache.flags < 0 ? 0 : 1;
468 break;
469 case POWER_SUPPLY_PROP_CURRENT_NOW:
470 ret = bq27x00_battery_current(di, val);
471 break;
472 case POWER_SUPPLY_PROP_CAPACITY:
473 ret = bq27x00_simple_value(di->cache.capacity, val);
474 break;
475 case POWER_SUPPLY_PROP_TEMP:
476 ret = bq27x00_battery_temperature(di, val);
477 break;
478 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
479 ret = bq27x00_simple_value(di->cache.time_to_empty, val);
480 break;
481 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
482 ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
483 break;
484 case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
485 ret = bq27x00_simple_value(di->cache.time_to_full, val);
486 break;
487 case POWER_SUPPLY_PROP_TECHNOLOGY:
488 val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
489 break;
490 case POWER_SUPPLY_PROP_CHARGE_NOW:
491 ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
492 break;
493 case POWER_SUPPLY_PROP_CHARGE_FULL:
494 ret = bq27x00_simple_value(di->cache.charge_full, val);
495 break;
496 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
497 ret = bq27x00_simple_value(di->charge_design_full, val);
498 break;
499 case POWER_SUPPLY_PROP_CHARGE_COUNTER:
500 ret = bq27x00_simple_value(di->cache.charge_counter, val);
501 break;
502 case POWER_SUPPLY_PROP_ENERGY_NOW:
503 ret = bq27x00_battery_energy(di, val);
504 break;
505 default:
506 return -EINVAL;
507 }
508
509 return ret;
510 }
511
512 static void bq27x00_external_power_changed(struct power_supply *psy)
513 {
514 struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
515
516 cancel_delayed_work_sync(&di->work);
517 schedule_delayed_work(&di->work, 0);
518 }
519
520 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
521 {
522 int ret;
523
524 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
525 di->bat.properties = bq27x00_battery_props;
526 di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
527 di->bat.get_property = bq27x00_battery_get_property;
528 di->bat.external_power_changed = bq27x00_external_power_changed;
529
530 INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
531 mutex_init(&di->lock);
532
533 ret = power_supply_register(di->dev, &di->bat);
534 if (ret) {
535 dev_err(di->dev, "failed to register battery: %d\n", ret);
536 return ret;
537 }
538
539 dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
540
541 bq27x00_update(di);
542
543 return 0;
544 }
545
546 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
547 {
548 cancel_delayed_work_sync(&di->work);
549
550 power_supply_unregister(&di->bat);
551
552 mutex_destroy(&di->lock);
553 }
554
555
556 /* i2c specific code */
557 #ifdef CONFIG_BATTERY_BQ27X00_I2C
558
559 /* If the system has several batteries we need a different name for each
560 * of them...
561 */
562 static DEFINE_IDR(battery_id);
563 static DEFINE_MUTEX(battery_mutex);
564
565 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
566 {
567 struct i2c_client *client = to_i2c_client(di->dev);
568 struct i2c_msg msg[2];
569 unsigned char data[2];
570 int ret;
571
572 if (!client->adapter)
573 return -ENODEV;
574
575 msg[0].addr = client->addr;
576 msg[0].flags = 0;
577 msg[0].buf = &reg;
578 msg[0].len = sizeof(reg);
579 msg[1].addr = client->addr;
580 msg[1].flags = I2C_M_RD;
581 msg[1].buf = data;
582 if (single)
583 msg[1].len = 1;
584 else
585 msg[1].len = 2;
586
587 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
588 if (ret < 0)
589 return ret;
590
591 if (!single)
592 ret = get_unaligned_le16(data);
593 else
594 ret = data[0];
595
596 return ret;
597 }
598
599 static int bq27x00_battery_probe(struct i2c_client *client,
600 const struct i2c_device_id *id)
601 {
602 char *name;
603 struct bq27x00_device_info *di;
604 int num;
605 int retval = 0;
606
607 /* Get new ID for the new battery device */
608 retval = idr_pre_get(&battery_id, GFP_KERNEL);
609 if (retval == 0)
610 return -ENOMEM;
611 mutex_lock(&battery_mutex);
612 retval = idr_get_new(&battery_id, client, &num);
613 mutex_unlock(&battery_mutex);
614 if (retval < 0)
615 return retval;
616
617 name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
618 if (!name) {
619 dev_err(&client->dev, "failed to allocate device name\n");
620 retval = -ENOMEM;
621 goto batt_failed_1;
622 }
623
624 di = kzalloc(sizeof(*di), GFP_KERNEL);
625 if (!di) {
626 dev_err(&client->dev, "failed to allocate device info data\n");
627 retval = -ENOMEM;
628 goto batt_failed_2;
629 }
630
631 di->id = num;
632 di->dev = &client->dev;
633 di->chip = id->driver_data;
634 di->bat.name = name;
635 di->bus.read = &bq27x00_read_i2c;
636
637 if (bq27x00_powersupply_init(di))
638 goto batt_failed_3;
639
640 i2c_set_clientdata(client, di);
641
642 return 0;
643
644 batt_failed_3:
645 kfree(di);
646 batt_failed_2:
647 kfree(name);
648 batt_failed_1:
649 mutex_lock(&battery_mutex);
650 idr_remove(&battery_id, num);
651 mutex_unlock(&battery_mutex);
652
653 return retval;
654 }
655
656 static int bq27x00_battery_remove(struct i2c_client *client)
657 {
658 struct bq27x00_device_info *di = i2c_get_clientdata(client);
659
660 bq27x00_powersupply_unregister(di);
661
662 kfree(di->bat.name);
663
664 mutex_lock(&battery_mutex);
665 idr_remove(&battery_id, di->id);
666 mutex_unlock(&battery_mutex);
667
668 kfree(di);
669
670 return 0;
671 }
672
673 static const struct i2c_device_id bq27x00_id[] = {
674 { "bq27200", BQ27000 }, /* bq27200 is same as bq27000, but with i2c */
675 { "bq27500", BQ27500 },
676 {},
677 };
678 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
679
680 static struct i2c_driver bq27x00_battery_driver = {
681 .driver = {
682 .name = "bq27x00-battery",
683 },
684 .probe = bq27x00_battery_probe,
685 .remove = bq27x00_battery_remove,
686 .id_table = bq27x00_id,
687 };
688
689 static inline int bq27x00_battery_i2c_init(void)
690 {
691 int ret = i2c_add_driver(&bq27x00_battery_driver);
692 if (ret)
693 printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
694
695 return ret;
696 }
697
698 static inline void bq27x00_battery_i2c_exit(void)
699 {
700 i2c_del_driver(&bq27x00_battery_driver);
701 }
702
703 #else
704
705 static inline int bq27x00_battery_i2c_init(void) { return 0; }
706 static inline void bq27x00_battery_i2c_exit(void) {};
707
708 #endif
709
710 /* platform specific code */
711 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
712
713 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
714 bool single)
715 {
716 struct device *dev = di->dev;
717 struct bq27000_platform_data *pdata = dev->platform_data;
718 unsigned int timeout = 3;
719 int upper, lower;
720 int temp;
721
722 if (!single) {
723 /* Make sure the value has not changed in between reading the
724 * lower and the upper part */
725 upper = pdata->read(dev, reg + 1);
726 do {
727 temp = upper;
728 if (upper < 0)
729 return upper;
730
731 lower = pdata->read(dev, reg);
732 if (lower < 0)
733 return lower;
734
735 upper = pdata->read(dev, reg + 1);
736 } while (temp != upper && --timeout);
737
738 if (timeout == 0)
739 return -EIO;
740
741 return (upper << 8) | lower;
742 }
743
744 return pdata->read(dev, reg);
745 }
746
747 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
748 {
749 struct bq27x00_device_info *di;
750 struct bq27000_platform_data *pdata = pdev->dev.platform_data;
751 int ret;
752
753 if (!pdata) {
754 dev_err(&pdev->dev, "no platform_data supplied\n");
755 return -EINVAL;
756 }
757
758 if (!pdata->read) {
759 dev_err(&pdev->dev, "no hdq read callback supplied\n");
760 return -EINVAL;
761 }
762
763 di = kzalloc(sizeof(*di), GFP_KERNEL);
764 if (!di) {
765 dev_err(&pdev->dev, "failed to allocate device info data\n");
766 return -ENOMEM;
767 }
768
769 platform_set_drvdata(pdev, di);
770
771 di->dev = &pdev->dev;
772 di->chip = BQ27000;
773
774 di->bat.name = pdata->name ?: dev_name(&pdev->dev);
775 di->bus.read = &bq27000_read_platform;
776
777 ret = bq27x00_powersupply_init(di);
778 if (ret)
779 goto err_free;
780
781 return 0;
782
783 err_free:
784 platform_set_drvdata(pdev, NULL);
785 kfree(di);
786
787 return ret;
788 }
789
790 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
791 {
792 struct bq27x00_device_info *di = platform_get_drvdata(pdev);
793
794 bq27x00_powersupply_unregister(di);
795
796 platform_set_drvdata(pdev, NULL);
797 kfree(di);
798
799 return 0;
800 }
801
802 static struct platform_driver bq27000_battery_driver = {
803 .probe = bq27000_battery_probe,
804 .remove = __devexit_p(bq27000_battery_remove),
805 .driver = {
806 .name = "bq27000-battery",
807 .owner = THIS_MODULE,
808 },
809 };
810
811 static inline int bq27x00_battery_platform_init(void)
812 {
813 int ret = platform_driver_register(&bq27000_battery_driver);
814 if (ret)
815 printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
816
817 return ret;
818 }
819
820 static inline void bq27x00_battery_platform_exit(void)
821 {
822 platform_driver_unregister(&bq27000_battery_driver);
823 }
824
825 #else
826
827 static inline int bq27x00_battery_platform_init(void) { return 0; }
828 static inline void bq27x00_battery_platform_exit(void) {};
829
830 #endif
831
832 /*
833 * Module stuff
834 */
835
836 static int __init bq27x00_battery_init(void)
837 {
838 int ret;
839
840 ret = bq27x00_battery_i2c_init();
841 if (ret)
842 return ret;
843
844 ret = bq27x00_battery_platform_init();
845 if (ret)
846 bq27x00_battery_i2c_exit();
847
848 return ret;
849 }
850 module_init(bq27x00_battery_init);
851
852 static void __exit bq27x00_battery_exit(void)
853 {
854 bq27x00_battery_platform_exit();
855 bq27x00_battery_i2c_exit();
856 }
857 module_exit(bq27x00_battery_exit);
858
859 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
860 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
861 MODULE_LICENSE("GPL");