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1 /*
2  * Driver for batteries with DS2760 chips inside.
3  *
4  * Copyright © 2007 Anton Vorontsov
5  *	       2004-2007 Matt Reimer
6  *	       2004 Szabolcs Gyurko
7  *
8  * Use consistent with the GNU GPL is permitted,
9  * provided that this copyright notice is
10  * preserved in its entirety in all copies and derived works.
11  *
12  * Author:  Anton Vorontsov <cbou@mail.ru>
13  *	    February 2007
14  *
15  *	    Matt Reimer <mreimer@vpop.net>
16  *	    April 2004, 2005, 2007
17  *
18  *	    Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
19  *	    September 2004
20  */
21 
22 #include <linux/module.h>
23 #include <linux/param.h>
24 #include <linux/jiffies.h>
25 #include <linux/workqueue.h>
26 #include <linux/pm.h>
27 #include <linux/slab.h>
28 #include <linux/platform_device.h>
29 #include <linux/power_supply.h>
30 
31 #include "../w1/w1.h"
32 #include "../w1/slaves/w1_ds2760.h"
33 
34 struct ds2760_device_info {
35 	struct device *dev;
36 
37 	/* DS2760 data, valid after calling ds2760_battery_read_status() */
38 	unsigned long update_time;	/* jiffies when data read */
39 	char raw[DS2760_DATA_SIZE];	/* raw DS2760 data */
40 	int voltage_raw;		/* units of 4.88 mV */
41 	int voltage_uV;			/* units of µV */
42 	int current_raw;		/* units of 0.625 mA */
43 	int current_uA;			/* units of µA */
44 	int accum_current_raw;		/* units of 0.25 mAh */
45 	int accum_current_uAh;		/* units of µAh */
46 	int temp_raw;			/* units of 0.125 °C */
47 	int temp_C;			/* units of 0.1 °C */
48 	int rated_capacity;		/* units of µAh */
49 	int rem_capacity;		/* percentage */
50 	int full_active_uAh;		/* units of µAh */
51 	int empty_uAh;			/* units of µAh */
52 	int life_sec;			/* units of seconds */
53 	int charge_status;		/* POWER_SUPPLY_STATUS_* */
54 
55 	int full_counter;
56 	struct power_supply bat;
57 	struct device *w1_dev;
58 	struct workqueue_struct *monitor_wqueue;
59 	struct delayed_work monitor_work;
60 	struct delayed_work set_charged_work;
61 };
62 
63 static unsigned int cache_time = 1000;
64 module_param(cache_time, uint, 0644);
65 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
66 
67 static bool pmod_enabled;
68 module_param(pmod_enabled, bool, 0644);
69 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
70 
71 static unsigned int rated_capacity;
72 module_param(rated_capacity, uint, 0644);
73 MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
74 
75 static unsigned int current_accum;
76 module_param(current_accum, uint, 0644);
77 MODULE_PARM_DESC(current_accum, "current accumulator value");
78 
79 /* Some batteries have their rated capacity stored a N * 10 mAh, while
80  * others use an index into this table. */
81 static int rated_capacities[] = {
82 	0,
83 	920,	/* Samsung */
84 	920,	/* BYD */
85 	920,	/* Lishen */
86 	920,	/* NEC */
87 	1440,	/* Samsung */
88 	1440,	/* BYD */
89 #ifdef CONFIG_MACH_H4700
90 	1800,	/* HP iPAQ hx4700 3.7V 1800mAh (359113-001) */
91 #else
92 	1440,	/* Lishen */
93 #endif
94 	1440,	/* NEC */
95 	2880,	/* Samsung */
96 	2880,	/* BYD */
97 	2880,	/* Lishen */
98 	2880,	/* NEC */
99 #ifdef CONFIG_MACH_H4700
100 	0,
101 	3600,	/* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
102 #endif
103 };
104 
105 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
106  * temp is in Celsius */
battery_interpolate(int array[],int temp)107 static int battery_interpolate(int array[], int temp)
108 {
109 	int index, dt;
110 
111 	if (temp <= 0)
112 		return array[0];
113 	if (temp >= 40)
114 		return array[4];
115 
116 	index = temp / 10;
117 	dt    = temp % 10;
118 
119 	return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
120 }
121 
ds2760_battery_read_status(struct ds2760_device_info * di)122 static int ds2760_battery_read_status(struct ds2760_device_info *di)
123 {
124 	int ret, i, start, count, scale[5];
125 
126 	if (di->update_time && time_before(jiffies, di->update_time +
127 					   msecs_to_jiffies(cache_time)))
128 		return 0;
129 
130 	/* The first time we read the entire contents of SRAM/EEPROM,
131 	 * but after that we just read the interesting bits that change. */
132 	if (di->update_time == 0) {
133 		start = 0;
134 		count = DS2760_DATA_SIZE;
135 	} else {
136 		start = DS2760_VOLTAGE_MSB;
137 		count = DS2760_TEMP_LSB - start + 1;
138 	}
139 
140 	ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
141 	if (ret != count) {
142 		dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
143 			 di->w1_dev);
144 		return 1;
145 	}
146 
147 	di->update_time = jiffies;
148 
149 	/* DS2760 reports voltage in units of 4.88mV, but the battery class
150 	 * reports in units of uV, so convert by multiplying by 4880. */
151 	di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
152 			  (di->raw[DS2760_VOLTAGE_LSB] >> 5);
153 	di->voltage_uV = di->voltage_raw * 4880;
154 
155 	/* DS2760 reports current in signed units of 0.625mA, but the battery
156 	 * class reports in units of µA, so convert by multiplying by 625. */
157 	di->current_raw =
158 	    (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
159 			  (di->raw[DS2760_CURRENT_LSB] >> 3);
160 	di->current_uA = di->current_raw * 625;
161 
162 	/* DS2760 reports accumulated current in signed units of 0.25mAh. */
163 	di->accum_current_raw =
164 	    (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
165 			   di->raw[DS2760_CURRENT_ACCUM_LSB];
166 	di->accum_current_uAh = di->accum_current_raw * 250;
167 
168 	/* DS2760 reports temperature in signed units of 0.125°C, but the
169 	 * battery class reports in units of 1/10 °C, so we convert by
170 	 * multiplying by .125 * 10 = 1.25. */
171 	di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
172 				     (di->raw[DS2760_TEMP_LSB] >> 5);
173 	di->temp_C = di->temp_raw + (di->temp_raw / 4);
174 
175 	/* At least some battery monitors (e.g. HP iPAQ) store the battery's
176 	 * maximum rated capacity. */
177 	if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
178 		di->rated_capacity = rated_capacities[
179 			(unsigned int)di->raw[DS2760_RATED_CAPACITY]];
180 	else
181 		di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
182 
183 	di->rated_capacity *= 1000; /* convert to µAh */
184 
185 	/* Calculate the full level at the present temperature. */
186 	di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
187 			      di->raw[DS2760_ACTIVE_FULL + 1];
188 
189 	/* If the full_active_uAh value is not given, fall back to the rated
190 	 * capacity. This is likely to happen when chips are not part of the
191 	 * battery pack and is therefore not bootstrapped. */
192 	if (di->full_active_uAh == 0)
193 		di->full_active_uAh = di->rated_capacity / 1000L;
194 
195 	scale[0] = di->full_active_uAh;
196 	for (i = 1; i < 5; i++)
197 		scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
198 
199 	di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
200 	di->full_active_uAh *= 1000; /* convert to µAh */
201 
202 	/* Calculate the empty level at the present temperature. */
203 	scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
204 	for (i = 3; i >= 0; i--)
205 		scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
206 
207 	di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
208 	di->empty_uAh *= 1000; /* convert to µAh */
209 
210 	if (di->full_active_uAh == di->empty_uAh)
211 		di->rem_capacity = 0;
212 	else
213 		/* From Maxim Application Note 131: remaining capacity =
214 		 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
215 		di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
216 				    (di->full_active_uAh - di->empty_uAh);
217 
218 	if (di->rem_capacity < 0)
219 		di->rem_capacity = 0;
220 	if (di->rem_capacity > 100)
221 		di->rem_capacity = 100;
222 
223 	if (di->current_uA < -100L)
224 		di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
225 					/ (di->current_uA / 100L);
226 	else
227 		di->life_sec = 0;
228 
229 	return 0;
230 }
231 
ds2760_battery_set_current_accum(struct ds2760_device_info * di,unsigned int acr_val)232 static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
233 					     unsigned int acr_val)
234 {
235 	unsigned char acr[2];
236 
237 	/* acr is in units of 0.25 mAh */
238 	acr_val *= 4L;
239 	acr_val /= 1000;
240 
241 	acr[0] = acr_val >> 8;
242 	acr[1] = acr_val & 0xff;
243 
244 	if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
245 		dev_warn(di->dev, "ACR write failed\n");
246 }
247 
ds2760_battery_update_status(struct ds2760_device_info * di)248 static void ds2760_battery_update_status(struct ds2760_device_info *di)
249 {
250 	int old_charge_status = di->charge_status;
251 
252 	ds2760_battery_read_status(di);
253 
254 	if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
255 		di->full_counter = 0;
256 
257 	if (power_supply_am_i_supplied(&di->bat)) {
258 		if (di->current_uA > 10000) {
259 			di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
260 			di->full_counter = 0;
261 		} else if (di->current_uA < -5000) {
262 			if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
263 				dev_notice(di->dev, "not enough power to "
264 					   "charge\n");
265 			di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
266 			di->full_counter = 0;
267 		} else if (di->current_uA < 10000 &&
268 			    di->charge_status != POWER_SUPPLY_STATUS_FULL) {
269 
270 			/* Don't consider the battery to be full unless
271 			 * we've seen the current < 10 mA at least two
272 			 * consecutive times. */
273 
274 			di->full_counter++;
275 
276 			if (di->full_counter < 2) {
277 				di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
278 			} else {
279 				di->charge_status = POWER_SUPPLY_STATUS_FULL;
280 				ds2760_battery_set_current_accum(di,
281 						di->full_active_uAh);
282 			}
283 		}
284 	} else {
285 		di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
286 		di->full_counter = 0;
287 	}
288 
289 	if (di->charge_status != old_charge_status)
290 		power_supply_changed(&di->bat);
291 }
292 
ds2760_battery_write_status(struct ds2760_device_info * di,char status)293 static void ds2760_battery_write_status(struct ds2760_device_info *di,
294 					char status)
295 {
296 	if (status == di->raw[DS2760_STATUS_REG])
297 		return;
298 
299 	w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
300 	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
301 	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
302 }
303 
ds2760_battery_write_rated_capacity(struct ds2760_device_info * di,unsigned char rated_capacity)304 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
305 						unsigned char rated_capacity)
306 {
307 	if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
308 		return;
309 
310 	w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
311 	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
312 	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
313 }
314 
ds2760_battery_write_active_full(struct ds2760_device_info * di,int active_full)315 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
316 					     int active_full)
317 {
318 	unsigned char tmp[2] = {
319 		active_full >> 8,
320 		active_full & 0xff
321 	};
322 
323 	if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
324 	    tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
325 		return;
326 
327 	w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
328 	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
329 	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
330 
331 	/* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
332 	 * values won't be read back by ds2760_battery_read_status() */
333 	di->raw[DS2760_ACTIVE_FULL] = tmp[0];
334 	di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
335 }
336 
ds2760_battery_work(struct work_struct * work)337 static void ds2760_battery_work(struct work_struct *work)
338 {
339 	struct ds2760_device_info *di = container_of(work,
340 		struct ds2760_device_info, monitor_work.work);
341 	const int interval = HZ * 60;
342 
343 	dev_dbg(di->dev, "%s\n", __func__);
344 
345 	ds2760_battery_update_status(di);
346 	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
347 }
348 
349 #define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
350 					      bat);
351 
ds2760_battery_external_power_changed(struct power_supply * psy)352 static void ds2760_battery_external_power_changed(struct power_supply *psy)
353 {
354 	struct ds2760_device_info *di = to_ds2760_device_info(psy);
355 
356 	dev_dbg(di->dev, "%s\n", __func__);
357 
358 	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
359 }
360 
361 
ds2760_battery_set_charged_work(struct work_struct * work)362 static void ds2760_battery_set_charged_work(struct work_struct *work)
363 {
364 	char bias;
365 	struct ds2760_device_info *di = container_of(work,
366 		struct ds2760_device_info, set_charged_work.work);
367 
368 	dev_dbg(di->dev, "%s\n", __func__);
369 
370 	ds2760_battery_read_status(di);
371 
372 	/* When we get notified by external circuitry that the battery is
373 	 * considered fully charged now, we know that there is no current
374 	 * flow any more. However, the ds2760's internal current meter is
375 	 * too inaccurate to rely on - spec say something ~15% failure.
376 	 * Hence, we use the current offset bias register to compensate
377 	 * that error.
378 	 */
379 
380 	if (!power_supply_am_i_supplied(&di->bat))
381 		return;
382 
383 	bias = (signed char) di->current_raw +
384 		(signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
385 
386 	dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
387 
388 	w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
389 	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
390 	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
391 
392 	/* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
393 	 * value won't be read back by ds2760_battery_read_status() */
394 	di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
395 }
396 
ds2760_battery_set_charged(struct power_supply * psy)397 static void ds2760_battery_set_charged(struct power_supply *psy)
398 {
399 	struct ds2760_device_info *di = to_ds2760_device_info(psy);
400 
401 	/* postpone the actual work by 20 secs. This is for debouncing GPIO
402 	 * signals and to let the current value settle. See AN4188. */
403 	mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
404 }
405 
ds2760_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)406 static int ds2760_battery_get_property(struct power_supply *psy,
407 				       enum power_supply_property psp,
408 				       union power_supply_propval *val)
409 {
410 	struct ds2760_device_info *di = to_ds2760_device_info(psy);
411 
412 	switch (psp) {
413 	case POWER_SUPPLY_PROP_STATUS:
414 		val->intval = di->charge_status;
415 		return 0;
416 	default:
417 		break;
418 	}
419 
420 	ds2760_battery_read_status(di);
421 
422 	switch (psp) {
423 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
424 		val->intval = di->voltage_uV;
425 		break;
426 	case POWER_SUPPLY_PROP_CURRENT_NOW:
427 		val->intval = di->current_uA;
428 		break;
429 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
430 		val->intval = di->rated_capacity;
431 		break;
432 	case POWER_SUPPLY_PROP_CHARGE_FULL:
433 		val->intval = di->full_active_uAh;
434 		break;
435 	case POWER_SUPPLY_PROP_CHARGE_EMPTY:
436 		val->intval = di->empty_uAh;
437 		break;
438 	case POWER_SUPPLY_PROP_CHARGE_NOW:
439 		val->intval = di->accum_current_uAh;
440 		break;
441 	case POWER_SUPPLY_PROP_TEMP:
442 		val->intval = di->temp_C;
443 		break;
444 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
445 		val->intval = di->life_sec;
446 		break;
447 	case POWER_SUPPLY_PROP_CAPACITY:
448 		val->intval = di->rem_capacity;
449 		break;
450 	default:
451 		return -EINVAL;
452 	}
453 
454 	return 0;
455 }
456 
ds2760_battery_set_property(struct power_supply * psy,enum power_supply_property psp,const union power_supply_propval * val)457 static int ds2760_battery_set_property(struct power_supply *psy,
458 				       enum power_supply_property psp,
459 				       const union power_supply_propval *val)
460 {
461 	struct ds2760_device_info *di = to_ds2760_device_info(psy);
462 
463 	switch (psp) {
464 	case POWER_SUPPLY_PROP_CHARGE_FULL:
465 		/* the interface counts in uAh, convert the value */
466 		ds2760_battery_write_active_full(di, val->intval / 1000L);
467 		break;
468 
469 	case POWER_SUPPLY_PROP_CHARGE_NOW:
470 		/* ds2760_battery_set_current_accum() does the conversion */
471 		ds2760_battery_set_current_accum(di, val->intval);
472 		break;
473 
474 	default:
475 		return -EPERM;
476 	}
477 
478 	return 0;
479 }
480 
ds2760_battery_property_is_writeable(struct power_supply * psy,enum power_supply_property psp)481 static int ds2760_battery_property_is_writeable(struct power_supply *psy,
482 						enum power_supply_property psp)
483 {
484 	switch (psp) {
485 	case POWER_SUPPLY_PROP_CHARGE_FULL:
486 	case POWER_SUPPLY_PROP_CHARGE_NOW:
487 		return 1;
488 
489 	default:
490 		break;
491 	}
492 
493 	return 0;
494 }
495 
496 static enum power_supply_property ds2760_battery_props[] = {
497 	POWER_SUPPLY_PROP_STATUS,
498 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
499 	POWER_SUPPLY_PROP_CURRENT_NOW,
500 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
501 	POWER_SUPPLY_PROP_CHARGE_FULL,
502 	POWER_SUPPLY_PROP_CHARGE_EMPTY,
503 	POWER_SUPPLY_PROP_CHARGE_NOW,
504 	POWER_SUPPLY_PROP_TEMP,
505 	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
506 	POWER_SUPPLY_PROP_CAPACITY,
507 };
508 
ds2760_battery_probe(struct platform_device * pdev)509 static int ds2760_battery_probe(struct platform_device *pdev)
510 {
511 	char status;
512 	int retval = 0;
513 	struct ds2760_device_info *di;
514 
515 	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
516 	if (!di) {
517 		retval = -ENOMEM;
518 		goto di_alloc_failed;
519 	}
520 
521 	platform_set_drvdata(pdev, di);
522 
523 	di->dev			= &pdev->dev;
524 	di->w1_dev		= pdev->dev.parent;
525 	di->bat.name		= dev_name(&pdev->dev);
526 	di->bat.type		= POWER_SUPPLY_TYPE_BATTERY;
527 	di->bat.properties	= ds2760_battery_props;
528 	di->bat.num_properties	= ARRAY_SIZE(ds2760_battery_props);
529 	di->bat.get_property	= ds2760_battery_get_property;
530 	di->bat.set_property	= ds2760_battery_set_property;
531 	di->bat.property_is_writeable =
532 				  ds2760_battery_property_is_writeable;
533 	di->bat.set_charged	= ds2760_battery_set_charged;
534 	di->bat.external_power_changed =
535 				  ds2760_battery_external_power_changed;
536 
537 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
538 
539 	/* enable sleep mode feature */
540 	ds2760_battery_read_status(di);
541 	status = di->raw[DS2760_STATUS_REG];
542 	if (pmod_enabled)
543 		status |= DS2760_STATUS_PMOD;
544 	else
545 		status &= ~DS2760_STATUS_PMOD;
546 
547 	ds2760_battery_write_status(di, status);
548 
549 	/* set rated capacity from module param */
550 	if (rated_capacity)
551 		ds2760_battery_write_rated_capacity(di, rated_capacity);
552 
553 	/* set current accumulator if given as parameter.
554 	 * this should only be done for bootstrapping the value */
555 	if (current_accum)
556 		ds2760_battery_set_current_accum(di, current_accum);
557 
558 	retval = power_supply_register(&pdev->dev, &di->bat);
559 	if (retval) {
560 		dev_err(di->dev, "failed to register battery\n");
561 		goto batt_failed;
562 	}
563 
564 	INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
565 	INIT_DELAYED_WORK(&di->set_charged_work,
566 			  ds2760_battery_set_charged_work);
567 	di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
568 	if (!di->monitor_wqueue) {
569 		retval = -ESRCH;
570 		goto workqueue_failed;
571 	}
572 	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
573 
574 	goto success;
575 
576 workqueue_failed:
577 	power_supply_unregister(&di->bat);
578 batt_failed:
579 di_alloc_failed:
580 success:
581 	return retval;
582 }
583 
ds2760_battery_remove(struct platform_device * pdev)584 static int ds2760_battery_remove(struct platform_device *pdev)
585 {
586 	struct ds2760_device_info *di = platform_get_drvdata(pdev);
587 
588 	cancel_delayed_work_sync(&di->monitor_work);
589 	cancel_delayed_work_sync(&di->set_charged_work);
590 	destroy_workqueue(di->monitor_wqueue);
591 	power_supply_unregister(&di->bat);
592 
593 	return 0;
594 }
595 
596 #ifdef CONFIG_PM
597 
ds2760_battery_suspend(struct platform_device * pdev,pm_message_t state)598 static int ds2760_battery_suspend(struct platform_device *pdev,
599 				  pm_message_t state)
600 {
601 	struct ds2760_device_info *di = platform_get_drvdata(pdev);
602 
603 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
604 
605 	return 0;
606 }
607 
ds2760_battery_resume(struct platform_device * pdev)608 static int ds2760_battery_resume(struct platform_device *pdev)
609 {
610 	struct ds2760_device_info *di = platform_get_drvdata(pdev);
611 
612 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
613 	power_supply_changed(&di->bat);
614 
615 	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
616 
617 	return 0;
618 }
619 
620 #else
621 
622 #define ds2760_battery_suspend NULL
623 #define ds2760_battery_resume NULL
624 
625 #endif /* CONFIG_PM */
626 
627 MODULE_ALIAS("platform:ds2760-battery");
628 
629 static struct platform_driver ds2760_battery_driver = {
630 	.driver = {
631 		.name = "ds2760-battery",
632 	},
633 	.probe	  = ds2760_battery_probe,
634 	.remove   = ds2760_battery_remove,
635 	.suspend  = ds2760_battery_suspend,
636 	.resume	  = ds2760_battery_resume,
637 };
638 
639 module_platform_driver(ds2760_battery_driver);
640 
641 MODULE_LICENSE("GPL");
642 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
643 	      "Matt Reimer <mreimer@vpop.net>, "
644 	      "Anton Vorontsov <cbou@mail.ru>");
645 MODULE_DESCRIPTION("ds2760 battery driver");
646