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  * Copyright (C) 2011 Pali Rohár <pali.rohar@gmail.com>
8  *
9  * Based on a previous work by Copyright (C) 2008 Texas Instruments, Inc.
10  *
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.
14  *
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.
18  *
19  */
20 
21 /*
22  * Datasheets:
23  * http://focus.ti.com/docs/prod/folders/print/bq27000.html
24  * http://focus.ti.com/docs/prod/folders/print/bq27500.html
25  */
26 
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>
38 
39 #include <linux/power/bq27x00_battery.h>
40 
41 #define DRIVER_VERSION			"1.2.0"
42 
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 capacity */
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 energy */
54 
55 #define BQ27000_REG_RSOC		0x0B /* Relative State-of-Charge */
56 #define BQ27000_REG_ILMD		0x76 /* Initial last measured discharge */
57 #define BQ27000_FLAG_EDVF		BIT(0) /* Final End-of-Discharge-Voltage flag */
58 #define BQ27000_FLAG_EDV1		BIT(1) /* First End-of-Discharge-Voltage flag */
59 #define BQ27000_FLAG_CI			BIT(4) /* Capacity Inaccurate flag */
60 #define BQ27000_FLAG_FC			BIT(5)
61 #define BQ27000_FLAG_CHGS		BIT(7) /* Charge state flag */
62 
63 #define BQ27500_REG_SOC			0x2C
64 #define BQ27500_REG_DCAP		0x3C /* Design capacity */
65 #define BQ27500_FLAG_DSC		BIT(0)
66 #define BQ27500_FLAG_SOCF		BIT(1) /* State-of-Charge threshold final */
67 #define BQ27500_FLAG_SOC1		BIT(2) /* State-of-Charge threshold 1 */
68 #define BQ27500_FLAG_FC			BIT(9)
69 
70 #define BQ27000_RS			20 /* Resistor sense */
71 
72 struct bq27x00_device_info;
73 struct bq27x00_access_methods {
74 	int (*read)(struct bq27x00_device_info *di, u8 reg, bool single);
75 };
76 
77 enum bq27x00_chip { BQ27000, BQ27500 };
78 
79 struct bq27x00_reg_cache {
80 	int temperature;
81 	int time_to_empty;
82 	int time_to_empty_avg;
83 	int time_to_full;
84 	int charge_full;
85 	int cycle_count;
86 	int capacity;
87 	int energy;
88 	int flags;
89 };
90 
91 struct bq27x00_device_info {
92 	struct device 		*dev;
93 	int			id;
94 	enum bq27x00_chip	chip;
95 
96 	struct bq27x00_reg_cache cache;
97 	int charge_design_full;
98 
99 	unsigned long last_update;
100 	struct delayed_work work;
101 
102 	struct power_supply	bat;
103 
104 	struct bq27x00_access_methods bus;
105 
106 	struct mutex lock;
107 };
108 
109 static enum power_supply_property bq27x00_battery_props[] = {
110 	POWER_SUPPLY_PROP_STATUS,
111 	POWER_SUPPLY_PROP_PRESENT,
112 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
113 	POWER_SUPPLY_PROP_CURRENT_NOW,
114 	POWER_SUPPLY_PROP_CAPACITY,
115 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
116 	POWER_SUPPLY_PROP_TEMP,
117 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
118 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
119 	POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
120 	POWER_SUPPLY_PROP_TECHNOLOGY,
121 	POWER_SUPPLY_PROP_CHARGE_FULL,
122 	POWER_SUPPLY_PROP_CHARGE_NOW,
123 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
124 	POWER_SUPPLY_PROP_CYCLE_COUNT,
125 	POWER_SUPPLY_PROP_ENERGY_NOW,
126 };
127 
128 static unsigned int poll_interval = 360;
129 module_param(poll_interval, uint, 0644);
130 MODULE_PARM_DESC(poll_interval, "battery poll interval in seconds - " \
131 				"0 disables polling");
132 
133 /*
134  * Common code for BQ27x00 devices
135  */
136 
bq27x00_read(struct bq27x00_device_info * di,u8 reg,bool single)137 static inline int bq27x00_read(struct bq27x00_device_info *di, u8 reg,
138 		bool single)
139 {
140 	return di->bus.read(di, reg, single);
141 }
142 
143 /*
144  * Return the battery Relative State-of-Charge
145  * Or < 0 if something fails.
146  */
bq27x00_battery_read_rsoc(struct bq27x00_device_info * di)147 static int bq27x00_battery_read_rsoc(struct bq27x00_device_info *di)
148 {
149 	int rsoc;
150 
151 	if (di->chip == BQ27500)
152 		rsoc = bq27x00_read(di, BQ27500_REG_SOC, false);
153 	else
154 		rsoc = bq27x00_read(di, BQ27000_REG_RSOC, true);
155 
156 	if (rsoc < 0)
157 		dev_dbg(di->dev, "error reading relative State-of-Charge\n");
158 
159 	return rsoc;
160 }
161 
162 /*
163  * Return a battery charge value in µAh
164  * Or < 0 if something fails.
165  */
bq27x00_battery_read_charge(struct bq27x00_device_info * di,u8 reg)166 static int bq27x00_battery_read_charge(struct bq27x00_device_info *di, u8 reg)
167 {
168 	int charge;
169 
170 	charge = bq27x00_read(di, reg, false);
171 	if (charge < 0) {
172 		dev_dbg(di->dev, "error reading charge register %02x: %d\n",
173 			reg, charge);
174 		return charge;
175 	}
176 
177 	if (di->chip == BQ27500)
178 		charge *= 1000;
179 	else
180 		charge = charge * 3570 / BQ27000_RS;
181 
182 	return charge;
183 }
184 
185 /*
186  * Return the battery Nominal available capaciy in µAh
187  * Or < 0 if something fails.
188  */
bq27x00_battery_read_nac(struct bq27x00_device_info * di)189 static inline int bq27x00_battery_read_nac(struct bq27x00_device_info *di)
190 {
191 	return bq27x00_battery_read_charge(di, BQ27x00_REG_NAC);
192 }
193 
194 /*
195  * Return the battery Last measured discharge in µAh
196  * Or < 0 if something fails.
197  */
bq27x00_battery_read_lmd(struct bq27x00_device_info * di)198 static inline int bq27x00_battery_read_lmd(struct bq27x00_device_info *di)
199 {
200 	return bq27x00_battery_read_charge(di, BQ27x00_REG_LMD);
201 }
202 
203 /*
204  * Return the battery Initial last measured discharge in µAh
205  * Or < 0 if something fails.
206  */
bq27x00_battery_read_ilmd(struct bq27x00_device_info * di)207 static int bq27x00_battery_read_ilmd(struct bq27x00_device_info *di)
208 {
209 	int ilmd;
210 
211 	if (di->chip == BQ27500)
212 		ilmd = bq27x00_read(di, BQ27500_REG_DCAP, false);
213 	else
214 		ilmd = bq27x00_read(di, BQ27000_REG_ILMD, true);
215 
216 	if (ilmd < 0) {
217 		dev_dbg(di->dev, "error reading initial last measured discharge\n");
218 		return ilmd;
219 	}
220 
221 	if (di->chip == BQ27500)
222 		ilmd *= 1000;
223 	else
224 		ilmd = ilmd * 256 * 3570 / BQ27000_RS;
225 
226 	return ilmd;
227 }
228 
229 /*
230  * Return the battery Available energy in µWh
231  * Or < 0 if something fails.
232  */
bq27x00_battery_read_energy(struct bq27x00_device_info * di)233 static int bq27x00_battery_read_energy(struct bq27x00_device_info *di)
234 {
235 	int ae;
236 
237 	ae = bq27x00_read(di, BQ27x00_REG_AE, false);
238 	if (ae < 0) {
239 		dev_dbg(di->dev, "error reading available energy\n");
240 		return ae;
241 	}
242 
243 	if (di->chip == BQ27500)
244 		ae *= 1000;
245 	else
246 		ae = ae * 29200 / BQ27000_RS;
247 
248 	return ae;
249 }
250 
251 /*
252  * Return the battery temperature in tenths of degree Celsius
253  * Or < 0 if something fails.
254  */
bq27x00_battery_read_temperature(struct bq27x00_device_info * di)255 static int bq27x00_battery_read_temperature(struct bq27x00_device_info *di)
256 {
257 	int temp;
258 
259 	temp = bq27x00_read(di, BQ27x00_REG_TEMP, false);
260 	if (temp < 0) {
261 		dev_err(di->dev, "error reading temperature\n");
262 		return temp;
263 	}
264 
265 	if (di->chip == BQ27500)
266 		temp -= 2731;
267 	else
268 		temp = ((temp * 5) - 5463) / 2;
269 
270 	return temp;
271 }
272 
273 /*
274  * Return the battery Cycle count total
275  * Or < 0 if something fails.
276  */
bq27x00_battery_read_cyct(struct bq27x00_device_info * di)277 static int bq27x00_battery_read_cyct(struct bq27x00_device_info *di)
278 {
279 	int cyct;
280 
281 	cyct = bq27x00_read(di, BQ27x00_REG_CYCT, false);
282 	if (cyct < 0)
283 		dev_err(di->dev, "error reading cycle count total\n");
284 
285 	return cyct;
286 }
287 
288 /*
289  * Read a time register.
290  * Return < 0 if something fails.
291  */
bq27x00_battery_read_time(struct bq27x00_device_info * di,u8 reg)292 static int bq27x00_battery_read_time(struct bq27x00_device_info *di, u8 reg)
293 {
294 	int tval;
295 
296 	tval = bq27x00_read(di, reg, false);
297 	if (tval < 0) {
298 		dev_dbg(di->dev, "error reading time register %02x: %d\n",
299 			reg, tval);
300 		return tval;
301 	}
302 
303 	if (tval == 65535)
304 		return -ENODATA;
305 
306 	return tval * 60;
307 }
308 
bq27x00_update(struct bq27x00_device_info * di)309 static void bq27x00_update(struct bq27x00_device_info *di)
310 {
311 	struct bq27x00_reg_cache cache = {0, };
312 	bool is_bq27500 = di->chip == BQ27500;
313 
314 	cache.flags = bq27x00_read(di, BQ27x00_REG_FLAGS, !is_bq27500);
315 	if (cache.flags >= 0) {
316 		if (!is_bq27500 && (cache.flags & BQ27000_FLAG_CI)) {
317 			dev_info(di->dev, "battery is not calibrated! ignoring capacity values\n");
318 			cache.capacity = -ENODATA;
319 			cache.energy = -ENODATA;
320 			cache.time_to_empty = -ENODATA;
321 			cache.time_to_empty_avg = -ENODATA;
322 			cache.time_to_full = -ENODATA;
323 			cache.charge_full = -ENODATA;
324 		} else {
325 			cache.capacity = bq27x00_battery_read_rsoc(di);
326 			cache.energy = bq27x00_battery_read_energy(di);
327 			cache.time_to_empty = bq27x00_battery_read_time(di, BQ27x00_REG_TTE);
328 			cache.time_to_empty_avg = bq27x00_battery_read_time(di, BQ27x00_REG_TTECP);
329 			cache.time_to_full = bq27x00_battery_read_time(di, BQ27x00_REG_TTF);
330 			cache.charge_full = bq27x00_battery_read_lmd(di);
331 		}
332 		cache.temperature = bq27x00_battery_read_temperature(di);
333 		cache.cycle_count = bq27x00_battery_read_cyct(di);
334 
335 		/* We only have to read charge design full once */
336 		if (di->charge_design_full <= 0)
337 			di->charge_design_full = bq27x00_battery_read_ilmd(di);
338 	}
339 
340 	if (memcmp(&di->cache, &cache, sizeof(cache)) != 0) {
341 		di->cache = cache;
342 		power_supply_changed(&di->bat);
343 	}
344 
345 	di->last_update = jiffies;
346 }
347 
bq27x00_battery_poll(struct work_struct * work)348 static void bq27x00_battery_poll(struct work_struct *work)
349 {
350 	struct bq27x00_device_info *di =
351 		container_of(work, struct bq27x00_device_info, work.work);
352 
353 	bq27x00_update(di);
354 
355 	if (poll_interval > 0) {
356 		/* The timer does not have to be accurate. */
357 		set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
358 		schedule_delayed_work(&di->work, poll_interval * HZ);
359 	}
360 }
361 
362 /*
363  * Return the battery average current in µA
364  * Note that current can be negative signed as well
365  * Or 0 if something fails.
366  */
bq27x00_battery_current(struct bq27x00_device_info * di,union power_supply_propval * val)367 static int bq27x00_battery_current(struct bq27x00_device_info *di,
368 	union power_supply_propval *val)
369 {
370 	int curr;
371 	int flags;
372 
373 	curr = bq27x00_read(di, BQ27x00_REG_AI, false);
374 	if (curr < 0) {
375 		dev_err(di->dev, "error reading current\n");
376 		return curr;
377 	}
378 
379 	if (di->chip == BQ27500) {
380 		/* bq27500 returns signed value */
381 		val->intval = (int)((s16)curr) * 1000;
382 	} else {
383 		flags = bq27x00_read(di, BQ27x00_REG_FLAGS, false);
384 		if (flags & BQ27000_FLAG_CHGS) {
385 			dev_dbg(di->dev, "negative current!\n");
386 			curr = -curr;
387 		}
388 
389 		val->intval = curr * 3570 / BQ27000_RS;
390 	}
391 
392 	return 0;
393 }
394 
bq27x00_battery_status(struct bq27x00_device_info * di,union power_supply_propval * val)395 static int bq27x00_battery_status(struct bq27x00_device_info *di,
396 	union power_supply_propval *val)
397 {
398 	int status;
399 
400 	if (di->chip == BQ27500) {
401 		if (di->cache.flags & BQ27500_FLAG_FC)
402 			status = POWER_SUPPLY_STATUS_FULL;
403 		else if (di->cache.flags & BQ27500_FLAG_DSC)
404 			status = POWER_SUPPLY_STATUS_DISCHARGING;
405 		else
406 			status = POWER_SUPPLY_STATUS_CHARGING;
407 	} else {
408 		if (di->cache.flags & BQ27000_FLAG_FC)
409 			status = POWER_SUPPLY_STATUS_FULL;
410 		else if (di->cache.flags & BQ27000_FLAG_CHGS)
411 			status = POWER_SUPPLY_STATUS_CHARGING;
412 		else if (power_supply_am_i_supplied(&di->bat))
413 			status = POWER_SUPPLY_STATUS_NOT_CHARGING;
414 		else
415 			status = POWER_SUPPLY_STATUS_DISCHARGING;
416 	}
417 
418 	val->intval = status;
419 
420 	return 0;
421 }
422 
bq27x00_battery_capacity_level(struct bq27x00_device_info * di,union power_supply_propval * val)423 static int bq27x00_battery_capacity_level(struct bq27x00_device_info *di,
424 	union power_supply_propval *val)
425 {
426 	int level;
427 
428 	if (di->chip == BQ27500) {
429 		if (di->cache.flags & BQ27500_FLAG_FC)
430 			level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
431 		else if (di->cache.flags & BQ27500_FLAG_SOC1)
432 			level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
433 		else if (di->cache.flags & BQ27500_FLAG_SOCF)
434 			level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
435 		else
436 			level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
437 	} else {
438 		if (di->cache.flags & BQ27000_FLAG_FC)
439 			level = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
440 		else if (di->cache.flags & BQ27000_FLAG_EDV1)
441 			level = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
442 		else if (di->cache.flags & BQ27000_FLAG_EDVF)
443 			level = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
444 		else
445 			level = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
446 	}
447 
448 	val->intval = level;
449 
450 	return 0;
451 }
452 
453 /*
454  * Return the battery Voltage in milivolts
455  * Or < 0 if something fails.
456  */
bq27x00_battery_voltage(struct bq27x00_device_info * di,union power_supply_propval * val)457 static int bq27x00_battery_voltage(struct bq27x00_device_info *di,
458 	union power_supply_propval *val)
459 {
460 	int volt;
461 
462 	volt = bq27x00_read(di, BQ27x00_REG_VOLT, false);
463 	if (volt < 0) {
464 		dev_err(di->dev, "error reading voltage\n");
465 		return volt;
466 	}
467 
468 	val->intval = volt * 1000;
469 
470 	return 0;
471 }
472 
bq27x00_simple_value(int value,union power_supply_propval * val)473 static int bq27x00_simple_value(int value,
474 	union power_supply_propval *val)
475 {
476 	if (value < 0)
477 		return value;
478 
479 	val->intval = value;
480 
481 	return 0;
482 }
483 
484 #define to_bq27x00_device_info(x) container_of((x), \
485 				struct bq27x00_device_info, bat);
486 
bq27x00_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)487 static int bq27x00_battery_get_property(struct power_supply *psy,
488 					enum power_supply_property psp,
489 					union power_supply_propval *val)
490 {
491 	int ret = 0;
492 	struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
493 
494 	mutex_lock(&di->lock);
495 	if (time_is_before_jiffies(di->last_update + 5 * HZ)) {
496 		cancel_delayed_work_sync(&di->work);
497 		bq27x00_battery_poll(&di->work.work);
498 	}
499 	mutex_unlock(&di->lock);
500 
501 	if (psp != POWER_SUPPLY_PROP_PRESENT && di->cache.flags < 0)
502 		return -ENODEV;
503 
504 	switch (psp) {
505 	case POWER_SUPPLY_PROP_STATUS:
506 		ret = bq27x00_battery_status(di, val);
507 		break;
508 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
509 		ret = bq27x00_battery_voltage(di, val);
510 		break;
511 	case POWER_SUPPLY_PROP_PRESENT:
512 		val->intval = di->cache.flags < 0 ? 0 : 1;
513 		break;
514 	case POWER_SUPPLY_PROP_CURRENT_NOW:
515 		ret = bq27x00_battery_current(di, val);
516 		break;
517 	case POWER_SUPPLY_PROP_CAPACITY:
518 		ret = bq27x00_simple_value(di->cache.capacity, val);
519 		break;
520 	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
521 		ret = bq27x00_battery_capacity_level(di, val);
522 		break;
523 	case POWER_SUPPLY_PROP_TEMP:
524 		ret = bq27x00_simple_value(di->cache.temperature, val);
525 		break;
526 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
527 		ret = bq27x00_simple_value(di->cache.time_to_empty, val);
528 		break;
529 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
530 		ret = bq27x00_simple_value(di->cache.time_to_empty_avg, val);
531 		break;
532 	case POWER_SUPPLY_PROP_TIME_TO_FULL_NOW:
533 		ret = bq27x00_simple_value(di->cache.time_to_full, val);
534 		break;
535 	case POWER_SUPPLY_PROP_TECHNOLOGY:
536 		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
537 		break;
538 	case POWER_SUPPLY_PROP_CHARGE_NOW:
539 		ret = bq27x00_simple_value(bq27x00_battery_read_nac(di), val);
540 		break;
541 	case POWER_SUPPLY_PROP_CHARGE_FULL:
542 		ret = bq27x00_simple_value(di->cache.charge_full, val);
543 		break;
544 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
545 		ret = bq27x00_simple_value(di->charge_design_full, val);
546 		break;
547 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
548 		ret = bq27x00_simple_value(di->cache.cycle_count, val);
549 		break;
550 	case POWER_SUPPLY_PROP_ENERGY_NOW:
551 		ret = bq27x00_simple_value(di->cache.energy, val);
552 		break;
553 	default:
554 		return -EINVAL;
555 	}
556 
557 	return ret;
558 }
559 
bq27x00_external_power_changed(struct power_supply * psy)560 static void bq27x00_external_power_changed(struct power_supply *psy)
561 {
562 	struct bq27x00_device_info *di = to_bq27x00_device_info(psy);
563 
564 	cancel_delayed_work_sync(&di->work);
565 	schedule_delayed_work(&di->work, 0);
566 }
567 
bq27x00_powersupply_init(struct bq27x00_device_info * di)568 static int bq27x00_powersupply_init(struct bq27x00_device_info *di)
569 {
570 	int ret;
571 
572 	di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
573 	di->bat.properties = bq27x00_battery_props;
574 	di->bat.num_properties = ARRAY_SIZE(bq27x00_battery_props);
575 	di->bat.get_property = bq27x00_battery_get_property;
576 	di->bat.external_power_changed = bq27x00_external_power_changed;
577 
578 	INIT_DELAYED_WORK(&di->work, bq27x00_battery_poll);
579 	mutex_init(&di->lock);
580 
581 	ret = power_supply_register(di->dev, &di->bat);
582 	if (ret) {
583 		dev_err(di->dev, "failed to register battery: %d\n", ret);
584 		return ret;
585 	}
586 
587 	dev_info(di->dev, "support ver. %s enabled\n", DRIVER_VERSION);
588 
589 	bq27x00_update(di);
590 
591 	return 0;
592 }
593 
bq27x00_powersupply_unregister(struct bq27x00_device_info * di)594 static void bq27x00_powersupply_unregister(struct bq27x00_device_info *di)
595 {
596 	/*
597 	 * power_supply_unregister call bq27x00_battery_get_property which
598 	 * call bq27x00_battery_poll.
599 	 * Make sure that bq27x00_battery_poll will not call
600 	 * schedule_delayed_work again after unregister (which cause OOPS).
601 	 */
602 	poll_interval = 0;
603 
604 	cancel_delayed_work_sync(&di->work);
605 
606 	power_supply_unregister(&di->bat);
607 
608 	mutex_destroy(&di->lock);
609 }
610 
611 
612 /* i2c specific code */
613 #ifdef CONFIG_BATTERY_BQ27X00_I2C
614 
615 /* If the system has several batteries we need a different name for each
616  * of them...
617  */
618 static DEFINE_IDR(battery_id);
619 static DEFINE_MUTEX(battery_mutex);
620 
bq27x00_read_i2c(struct bq27x00_device_info * di,u8 reg,bool single)621 static int bq27x00_read_i2c(struct bq27x00_device_info *di, u8 reg, bool single)
622 {
623 	struct i2c_client *client = to_i2c_client(di->dev);
624 	struct i2c_msg msg[2];
625 	unsigned char data[2];
626 	int ret;
627 
628 	if (!client->adapter)
629 		return -ENODEV;
630 
631 	msg[0].addr = client->addr;
632 	msg[0].flags = 0;
633 	msg[0].buf = &reg;
634 	msg[0].len = sizeof(reg);
635 	msg[1].addr = client->addr;
636 	msg[1].flags = I2C_M_RD;
637 	msg[1].buf = data;
638 	if (single)
639 		msg[1].len = 1;
640 	else
641 		msg[1].len = 2;
642 
643 	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
644 	if (ret < 0)
645 		return ret;
646 
647 	if (!single)
648 		ret = get_unaligned_le16(data);
649 	else
650 		ret = data[0];
651 
652 	return ret;
653 }
654 
bq27x00_battery_probe(struct i2c_client * client,const struct i2c_device_id * id)655 static int bq27x00_battery_probe(struct i2c_client *client,
656 				 const struct i2c_device_id *id)
657 {
658 	char *name;
659 	struct bq27x00_device_info *di;
660 	int num;
661 	int retval = 0;
662 
663 	/* Get new ID for the new battery device */
664 	retval = idr_pre_get(&battery_id, GFP_KERNEL);
665 	if (retval == 0)
666 		return -ENOMEM;
667 	mutex_lock(&battery_mutex);
668 	retval = idr_get_new(&battery_id, client, &num);
669 	mutex_unlock(&battery_mutex);
670 	if (retval < 0)
671 		return retval;
672 
673 	name = kasprintf(GFP_KERNEL, "%s-%d", id->name, num);
674 	if (!name) {
675 		dev_err(&client->dev, "failed to allocate device name\n");
676 		retval = -ENOMEM;
677 		goto batt_failed_1;
678 	}
679 
680 	di = kzalloc(sizeof(*di), GFP_KERNEL);
681 	if (!di) {
682 		dev_err(&client->dev, "failed to allocate device info data\n");
683 		retval = -ENOMEM;
684 		goto batt_failed_2;
685 	}
686 
687 	di->id = num;
688 	di->dev = &client->dev;
689 	di->chip = id->driver_data;
690 	di->bat.name = name;
691 	di->bus.read = &bq27x00_read_i2c;
692 
693 	if (bq27x00_powersupply_init(di))
694 		goto batt_failed_3;
695 
696 	i2c_set_clientdata(client, di);
697 
698 	return 0;
699 
700 batt_failed_3:
701 	kfree(di);
702 batt_failed_2:
703 	kfree(name);
704 batt_failed_1:
705 	mutex_lock(&battery_mutex);
706 	idr_remove(&battery_id, num);
707 	mutex_unlock(&battery_mutex);
708 
709 	return retval;
710 }
711 
bq27x00_battery_remove(struct i2c_client * client)712 static int bq27x00_battery_remove(struct i2c_client *client)
713 {
714 	struct bq27x00_device_info *di = i2c_get_clientdata(client);
715 
716 	bq27x00_powersupply_unregister(di);
717 
718 	kfree(di->bat.name);
719 
720 	mutex_lock(&battery_mutex);
721 	idr_remove(&battery_id, di->id);
722 	mutex_unlock(&battery_mutex);
723 
724 	kfree(di);
725 
726 	return 0;
727 }
728 
729 static const struct i2c_device_id bq27x00_id[] = {
730 	{ "bq27200", BQ27000 },	/* bq27200 is same as bq27000, but with i2c */
731 	{ "bq27500", BQ27500 },
732 	{},
733 };
734 MODULE_DEVICE_TABLE(i2c, bq27x00_id);
735 
736 static struct i2c_driver bq27x00_battery_driver = {
737 	.driver = {
738 		.name = "bq27x00-battery",
739 	},
740 	.probe = bq27x00_battery_probe,
741 	.remove = bq27x00_battery_remove,
742 	.id_table = bq27x00_id,
743 };
744 
bq27x00_battery_i2c_init(void)745 static inline int bq27x00_battery_i2c_init(void)
746 {
747 	int ret = i2c_add_driver(&bq27x00_battery_driver);
748 	if (ret)
749 		printk(KERN_ERR "Unable to register BQ27x00 i2c driver\n");
750 
751 	return ret;
752 }
753 
bq27x00_battery_i2c_exit(void)754 static inline void bq27x00_battery_i2c_exit(void)
755 {
756 	i2c_del_driver(&bq27x00_battery_driver);
757 }
758 
759 #else
760 
bq27x00_battery_i2c_init(void)761 static inline int bq27x00_battery_i2c_init(void) { return 0; }
bq27x00_battery_i2c_exit(void)762 static inline void bq27x00_battery_i2c_exit(void) {};
763 
764 #endif
765 
766 /* platform specific code */
767 #ifdef CONFIG_BATTERY_BQ27X00_PLATFORM
768 
bq27000_read_platform(struct bq27x00_device_info * di,u8 reg,bool single)769 static int bq27000_read_platform(struct bq27x00_device_info *di, u8 reg,
770 			bool single)
771 {
772 	struct device *dev = di->dev;
773 	struct bq27000_platform_data *pdata = dev->platform_data;
774 	unsigned int timeout = 3;
775 	int upper, lower;
776 	int temp;
777 
778 	if (!single) {
779 		/* Make sure the value has not changed in between reading the
780 		 * lower and the upper part */
781 		upper = pdata->read(dev, reg + 1);
782 		do {
783 			temp = upper;
784 			if (upper < 0)
785 				return upper;
786 
787 			lower = pdata->read(dev, reg);
788 			if (lower < 0)
789 				return lower;
790 
791 			upper = pdata->read(dev, reg + 1);
792 		} while (temp != upper && --timeout);
793 
794 		if (timeout == 0)
795 			return -EIO;
796 
797 		return (upper << 8) | lower;
798 	}
799 
800 	return pdata->read(dev, reg);
801 }
802 
bq27000_battery_probe(struct platform_device * pdev)803 static int __devinit bq27000_battery_probe(struct platform_device *pdev)
804 {
805 	struct bq27x00_device_info *di;
806 	struct bq27000_platform_data *pdata = pdev->dev.platform_data;
807 	int ret;
808 
809 	if (!pdata) {
810 		dev_err(&pdev->dev, "no platform_data supplied\n");
811 		return -EINVAL;
812 	}
813 
814 	if (!pdata->read) {
815 		dev_err(&pdev->dev, "no hdq read callback supplied\n");
816 		return -EINVAL;
817 	}
818 
819 	di = kzalloc(sizeof(*di), GFP_KERNEL);
820 	if (!di) {
821 		dev_err(&pdev->dev, "failed to allocate device info data\n");
822 		return -ENOMEM;
823 	}
824 
825 	platform_set_drvdata(pdev, di);
826 
827 	di->dev = &pdev->dev;
828 	di->chip = BQ27000;
829 
830 	di->bat.name = pdata->name ?: dev_name(&pdev->dev);
831 	di->bus.read = &bq27000_read_platform;
832 
833 	ret = bq27x00_powersupply_init(di);
834 	if (ret)
835 		goto err_free;
836 
837 	return 0;
838 
839 err_free:
840 	platform_set_drvdata(pdev, NULL);
841 	kfree(di);
842 
843 	return ret;
844 }
845 
bq27000_battery_remove(struct platform_device * pdev)846 static int __devexit bq27000_battery_remove(struct platform_device *pdev)
847 {
848 	struct bq27x00_device_info *di = platform_get_drvdata(pdev);
849 
850 	bq27x00_powersupply_unregister(di);
851 
852 	platform_set_drvdata(pdev, NULL);
853 	kfree(di);
854 
855 	return 0;
856 }
857 
858 static struct platform_driver bq27000_battery_driver = {
859 	.probe	= bq27000_battery_probe,
860 	.remove = __devexit_p(bq27000_battery_remove),
861 	.driver = {
862 		.name = "bq27000-battery",
863 		.owner = THIS_MODULE,
864 	},
865 };
866 
bq27x00_battery_platform_init(void)867 static inline int bq27x00_battery_platform_init(void)
868 {
869 	int ret = platform_driver_register(&bq27000_battery_driver);
870 	if (ret)
871 		printk(KERN_ERR "Unable to register BQ27000 platform driver\n");
872 
873 	return ret;
874 }
875 
bq27x00_battery_platform_exit(void)876 static inline void bq27x00_battery_platform_exit(void)
877 {
878 	platform_driver_unregister(&bq27000_battery_driver);
879 }
880 
881 #else
882 
bq27x00_battery_platform_init(void)883 static inline int bq27x00_battery_platform_init(void) { return 0; }
bq27x00_battery_platform_exit(void)884 static inline void bq27x00_battery_platform_exit(void) {};
885 
886 #endif
887 
888 /*
889  * Module stuff
890  */
891 
bq27x00_battery_init(void)892 static int __init bq27x00_battery_init(void)
893 {
894 	int ret;
895 
896 	ret = bq27x00_battery_i2c_init();
897 	if (ret)
898 		return ret;
899 
900 	ret = bq27x00_battery_platform_init();
901 	if (ret)
902 		bq27x00_battery_i2c_exit();
903 
904 	return ret;
905 }
906 module_init(bq27x00_battery_init);
907 
bq27x00_battery_exit(void)908 static void __exit bq27x00_battery_exit(void)
909 {
910 	bq27x00_battery_platform_exit();
911 	bq27x00_battery_i2c_exit();
912 }
913 module_exit(bq27x00_battery_exit);
914 
915 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
916 MODULE_DESCRIPTION("BQ27x00 battery monitor driver");
917 MODULE_LICENSE("GPL");
918