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#include <linux/suspend.h>
31#include <linux/w1.h>
32#include <linux/of.h>
33
34static unsigned int cache_time = 1000;
35module_param(cache_time, uint, 0644);
36MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
37
38static bool pmod_enabled;
39module_param(pmod_enabled, bool, 0644);
40MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
41
42static unsigned int rated_capacity;
43module_param(rated_capacity, uint, 0644);
44MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
45
46static unsigned int current_accum;
47module_param(current_accum, uint, 0644);
48MODULE_PARM_DESC(current_accum, "current accumulator value");
49
50#define W1_FAMILY_DS2760		0x30
51
52/* Known commands to the DS2760 chip */
53#define W1_DS2760_SWAP			0xAA
54#define W1_DS2760_READ_DATA		0x69
55#define W1_DS2760_WRITE_DATA		0x6C
56#define W1_DS2760_COPY_DATA		0x48
57#define W1_DS2760_RECALL_DATA		0xB8
58#define W1_DS2760_LOCK			0x6A
59
60/* Number of valid register addresses */
61#define DS2760_DATA_SIZE		0x40
62
63#define DS2760_PROTECTION_REG		0x00
64
65#define DS2760_STATUS_REG		0x01
66#define DS2760_STATUS_IE		(1 << 2)
67#define DS2760_STATUS_SWEN		(1 << 3)
68#define DS2760_STATUS_RNAOP		(1 << 4)
69#define DS2760_STATUS_PMOD		(1 << 5)
70
71#define DS2760_EEPROM_REG		0x07
72#define DS2760_SPECIAL_FEATURE_REG	0x08
73#define DS2760_VOLTAGE_MSB		0x0c
74#define DS2760_VOLTAGE_LSB		0x0d
75#define DS2760_CURRENT_MSB		0x0e
76#define DS2760_CURRENT_LSB		0x0f
77#define DS2760_CURRENT_ACCUM_MSB	0x10
78#define DS2760_CURRENT_ACCUM_LSB	0x11
79#define DS2760_TEMP_MSB			0x18
80#define DS2760_TEMP_LSB			0x19
81#define DS2760_EEPROM_BLOCK0		0x20
82#define DS2760_ACTIVE_FULL		0x20
83#define DS2760_EEPROM_BLOCK1		0x30
84#define DS2760_STATUS_WRITE_REG		0x31
85#define DS2760_RATED_CAPACITY		0x32
86#define DS2760_CURRENT_OFFSET_BIAS	0x33
87#define DS2760_ACTIVE_EMPTY		0x3b
88
89struct ds2760_device_info {
90	struct device *dev;
91
92	/* DS2760 data, valid after calling ds2760_battery_read_status() */
93	unsigned long update_time;	/* jiffies when data read */
94	char raw[DS2760_DATA_SIZE];	/* raw DS2760 data */
95	int voltage_raw;		/* units of 4.88 mV */
96	int voltage_uV;			/* units of ��V */
97	int current_raw;		/* units of 0.625 mA */
98	int current_uA;			/* units of ��A */
99	int accum_current_raw;		/* units of 0.25 mAh */
100	int accum_current_uAh;		/* units of ��Ah */
101	int temp_raw;			/* units of 0.125 ��C */
102	int temp_C;			/* units of 0.1 ��C */
103	int rated_capacity;		/* units of ��Ah */
104	int rem_capacity;		/* percentage */
105	int full_active_uAh;		/* units of ��Ah */
106	int empty_uAh;			/* units of ��Ah */
107	int life_sec;			/* units of seconds */
108	int charge_status;		/* POWER_SUPPLY_STATUS_* */
109
110	int full_counter;
111	struct power_supply *bat;
112	struct power_supply_desc bat_desc;
113	struct workqueue_struct *monitor_wqueue;
114	struct delayed_work monitor_work;
115	struct delayed_work set_charged_work;
116	struct notifier_block pm_notifier;
117};
118
119static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
120			int io)
121{
122	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
123
124	if (!dev)
125		return 0;
126
127	mutex_lock(&sl->master->bus_mutex);
128
129	if (addr > DS2760_DATA_SIZE || addr < 0) {
130		count = 0;
131		goto out;
132	}
133	if (addr + count > DS2760_DATA_SIZE)
134		count = DS2760_DATA_SIZE - addr;
135
136	if (!w1_reset_select_slave(sl)) {
137		if (!io) {
138			w1_write_8(sl->master, W1_DS2760_READ_DATA);
139			w1_write_8(sl->master, addr);
140			count = w1_read_block(sl->master, buf, count);
141		} else {
142			w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
143			w1_write_8(sl->master, addr);
144			w1_write_block(sl->master, buf, count);
145			/* XXX w1_write_block returns void, not n_written */
146		}
147	}
148
149out:
150	mutex_unlock(&sl->master->bus_mutex);
151
152	return count;
153}
154
155static int w1_ds2760_read(struct device *dev,
156			  char *buf, int addr,
157			  size_t count)
158{
159	return w1_ds2760_io(dev, buf, addr, count, 0);
160}
161
162static int w1_ds2760_write(struct device *dev,
163			   char *buf,
164			   int addr, size_t count)
165{
166	return w1_ds2760_io(dev, buf, addr, count, 1);
167}
168
169static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
170{
171	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
172
173	if (!dev)
174		return -EINVAL;
175
176	mutex_lock(&sl->master->bus_mutex);
177
178	if (w1_reset_select_slave(sl) == 0) {
179		w1_write_8(sl->master, cmd);
180		w1_write_8(sl->master, addr);
181	}
182
183	mutex_unlock(&sl->master->bus_mutex);
184	return 0;
185}
186
187static int w1_ds2760_store_eeprom(struct device *dev, int addr)
188{
189	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
190}
191
192static int w1_ds2760_recall_eeprom(struct device *dev, int addr)
193{
194	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
195}
196
197static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
198			     struct bin_attribute *bin_attr, char *buf,
199			     loff_t off, size_t count)
200{
201	struct device *dev = kobj_to_dev(kobj);
202	return w1_ds2760_read(dev, buf, off, count);
203}
204
205static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
206
207static struct bin_attribute *w1_ds2760_bin_attrs[] = {
208	&bin_attr_w1_slave,
209	NULL,
210};
211
212static const struct attribute_group w1_ds2760_group = {
213	.bin_attrs = w1_ds2760_bin_attrs,
214};
215
216static const struct attribute_group *w1_ds2760_groups[] = {
217	&w1_ds2760_group,
218	NULL,
219};
220/* Some batteries have their rated capacity stored a N * 10 mAh, while
221 * others use an index into this table. */
222static int rated_capacities[] = {
223	0,
224	920,	/* Samsung */
225	920,	/* BYD */
226	920,	/* Lishen */
227	920,	/* NEC */
228	1440,	/* Samsung */
229	1440,	/* BYD */
230	1440,	/* Lishen */
231	1440,	/* NEC */
232	2880,	/* Samsung */
233	2880,	/* BYD */
234	2880,	/* Lishen */
235	2880,	/* NEC */
236};
237
238/* array is level at temps 0��C, 10��C, 20��C, 30��C, 40��C
239 * temp is in Celsius */
240static int battery_interpolate(int array[], int temp)
241{
242	int index, dt;
243
244	if (temp <= 0)
245		return array[0];
246	if (temp >= 40)
247		return array[4];
248
249	index = temp / 10;
250	dt    = temp % 10;
251
252	return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
253}
254
255static int ds2760_battery_read_status(struct ds2760_device_info *di)
256{
257	int ret, i, start, count, scale[5];
258
259	if (di->update_time && time_before(jiffies, di->update_time +
260					   msecs_to_jiffies(cache_time)))
261		return 0;
262
263	/* The first time we read the entire contents of SRAM/EEPROM,
264	 * but after that we just read the interesting bits that change. */
265	if (di->update_time == 0) {
266		start = 0;
267		count = DS2760_DATA_SIZE;
268	} else {
269		start = DS2760_VOLTAGE_MSB;
270		count = DS2760_TEMP_LSB - start + 1;
271	}
272
273	ret = w1_ds2760_read(di->dev, di->raw + start, start, count);
274	if (ret != count) {
275		dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
276			 di->dev);
277		return 1;
278	}
279
280	di->update_time = jiffies;
281
282	/* DS2760 reports voltage in units of 4.88mV, but the battery class
283	 * reports in units of uV, so convert by multiplying by 4880. */
284	di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
285			  (di->raw[DS2760_VOLTAGE_LSB] >> 5);
286	di->voltage_uV = di->voltage_raw * 4880;
287
288	/* DS2760 reports current in signed units of 0.625mA, but the battery
289	 * class reports in units of ��A, so convert by multiplying by 625. */
290	di->current_raw =
291	    (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
292			  (di->raw[DS2760_CURRENT_LSB] >> 3);
293	di->current_uA = di->current_raw * 625;
294
295	/* DS2760 reports accumulated current in signed units of 0.25mAh. */
296	di->accum_current_raw =
297	    (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
298			   di->raw[DS2760_CURRENT_ACCUM_LSB];
299	di->accum_current_uAh = di->accum_current_raw * 250;
300
301	/* DS2760 reports temperature in signed units of 0.125��C, but the
302	 * battery class reports in units of 1/10 ��C, so we convert by
303	 * multiplying by .125 * 10 = 1.25. */
304	di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
305				     (di->raw[DS2760_TEMP_LSB] >> 5);
306	di->temp_C = di->temp_raw + (di->temp_raw / 4);
307
308	/* At least some battery monitors (e.g. HP iPAQ) store the battery's
309	 * maximum rated capacity. */
310	if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
311		di->rated_capacity = rated_capacities[
312			(unsigned int)di->raw[DS2760_RATED_CAPACITY]];
313	else
314		di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
315
316	di->rated_capacity *= 1000; /* convert to ��Ah */
317
318	/* Calculate the full level at the present temperature. */
319	di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
320			      di->raw[DS2760_ACTIVE_FULL + 1];
321
322	/* If the full_active_uAh value is not given, fall back to the rated
323	 * capacity. This is likely to happen when chips are not part of the
324	 * battery pack and is therefore not bootstrapped. */
325	if (di->full_active_uAh == 0)
326		di->full_active_uAh = di->rated_capacity / 1000L;
327
328	scale[0] = di->full_active_uAh;
329	for (i = 1; i < 5; i++)
330		scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
331
332	di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
333	di->full_active_uAh *= 1000; /* convert to ��Ah */
334
335	/* Calculate the empty level at the present temperature. */
336	scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
337	for (i = 3; i >= 0; i--)
338		scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
339
340	di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
341	di->empty_uAh *= 1000; /* convert to ��Ah */
342
343	if (di->full_active_uAh == di->empty_uAh)
344		di->rem_capacity = 0;
345	else
346		/* From Maxim Application Note 131: remaining capacity =
347		 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
348		di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
349				    (di->full_active_uAh - di->empty_uAh);
350
351	if (di->rem_capacity < 0)
352		di->rem_capacity = 0;
353	if (di->rem_capacity > 100)
354		di->rem_capacity = 100;
355
356	if (di->current_uA < -100L)
357		di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
358					/ (di->current_uA / 100L);
359	else
360		di->life_sec = 0;
361
362	return 0;
363}
364
365static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
366					     unsigned int acr_val)
367{
368	unsigned char acr[2];
369
370	/* acr is in units of 0.25 mAh */
371	acr_val *= 4L;
372	acr_val /= 1000;
373
374	acr[0] = acr_val >> 8;
375	acr[1] = acr_val & 0xff;
376
377	if (w1_ds2760_write(di->dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
378		dev_warn(di->dev, "ACR write failed\n");
379}
380
381static void ds2760_battery_update_status(struct ds2760_device_info *di)
382{
383	int old_charge_status = di->charge_status;
384
385	ds2760_battery_read_status(di);
386
387	if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
388		di->full_counter = 0;
389
390	if (power_supply_am_i_supplied(di->bat)) {
391		if (di->current_uA > 10000) {
392			di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
393			di->full_counter = 0;
394		} else if (di->current_uA < -5000) {
395			if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
396				dev_notice(di->dev, "not enough power to "
397					   "charge\n");
398			di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
399			di->full_counter = 0;
400		} else if (di->current_uA < 10000 &&
401			    di->charge_status != POWER_SUPPLY_STATUS_FULL) {
402
403			/* Don't consider the battery to be full unless
404			 * we've seen the current < 10 mA at least two
405			 * consecutive times. */
406
407			di->full_counter++;
408
409			if (di->full_counter < 2) {
410				di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
411			} else {
412				di->charge_status = POWER_SUPPLY_STATUS_FULL;
413				ds2760_battery_set_current_accum(di,
414						di->full_active_uAh);
415			}
416		}
417	} else {
418		di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
419		di->full_counter = 0;
420	}
421
422	if (di->charge_status != old_charge_status)
423		power_supply_changed(di->bat);
424}
425
426static void ds2760_battery_write_status(struct ds2760_device_info *di,
427					char status)
428{
429	if (status == di->raw[DS2760_STATUS_REG])
430		return;
431
432	w1_ds2760_write(di->dev, &status, DS2760_STATUS_WRITE_REG, 1);
433	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
434	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
435}
436
437static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
438						unsigned char rated_capacity)
439{
440	if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
441		return;
442
443	w1_ds2760_write(di->dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
444	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
445	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
446}
447
448static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
449					     int active_full)
450{
451	unsigned char tmp[2] = {
452		active_full >> 8,
453		active_full & 0xff
454	};
455
456	if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
457	    tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
458		return;
459
460	w1_ds2760_write(di->dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
461	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
462	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
463
464	/* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
465	 * values won't be read back by ds2760_battery_read_status() */
466	di->raw[DS2760_ACTIVE_FULL] = tmp[0];
467	di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
468}
469
470static void ds2760_battery_work(struct work_struct *work)
471{
472	struct ds2760_device_info *di = container_of(work,
473		struct ds2760_device_info, monitor_work.work);
474	const int interval = HZ * 60;
475
476	dev_dbg(di->dev, "%s\n", __func__);
477
478	ds2760_battery_update_status(di);
479	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
480}
481
482static void ds2760_battery_external_power_changed(struct power_supply *psy)
483{
484	struct ds2760_device_info *di = power_supply_get_drvdata(psy);
485
486	dev_dbg(di->dev, "%s\n", __func__);
487
488	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
489}
490
491
492static void ds2760_battery_set_charged_work(struct work_struct *work)
493{
494	char bias;
495	struct ds2760_device_info *di = container_of(work,
496		struct ds2760_device_info, set_charged_work.work);
497
498	dev_dbg(di->dev, "%s\n", __func__);
499
500	ds2760_battery_read_status(di);
501
502	/* When we get notified by external circuitry that the battery is
503	 * considered fully charged now, we know that there is no current
504	 * flow any more. However, the ds2760's internal current meter is
505	 * too inaccurate to rely on - spec say something ~15% failure.
506	 * Hence, we use the current offset bias register to compensate
507	 * that error.
508	 */
509
510	if (!power_supply_am_i_supplied(di->bat))
511		return;
512
513	bias = (signed char) di->current_raw +
514		(signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
515
516	dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
517
518	w1_ds2760_write(di->dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
519	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
520	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
521
522	/* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
523	 * value won't be read back by ds2760_battery_read_status() */
524	di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
525}
526
527static void ds2760_battery_set_charged(struct power_supply *psy)
528{
529	struct ds2760_device_info *di = power_supply_get_drvdata(psy);
530
531	/* postpone the actual work by 20 secs. This is for debouncing GPIO
532	 * signals and to let the current value settle. See AN4188. */
533	mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
534}
535
536static int ds2760_battery_get_property(struct power_supply *psy,
537				       enum power_supply_property psp,
538				       union power_supply_propval *val)
539{
540	struct ds2760_device_info *di = power_supply_get_drvdata(psy);
541
542	switch (psp) {
543	case POWER_SUPPLY_PROP_STATUS:
544		val->intval = di->charge_status;
545		return 0;
546	default:
547		break;
548	}
549
550	ds2760_battery_read_status(di);
551
552	switch (psp) {
553	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
554		val->intval = di->voltage_uV;
555		break;
556	case POWER_SUPPLY_PROP_CURRENT_NOW:
557		val->intval = di->current_uA;
558		break;
559	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
560		val->intval = di->rated_capacity;
561		break;
562	case POWER_SUPPLY_PROP_CHARGE_FULL:
563		val->intval = di->full_active_uAh;
564		break;
565	case POWER_SUPPLY_PROP_CHARGE_EMPTY:
566		val->intval = di->empty_uAh;
567		break;
568	case POWER_SUPPLY_PROP_CHARGE_NOW:
569		val->intval = di->accum_current_uAh;
570		break;
571	case POWER_SUPPLY_PROP_TEMP:
572		val->intval = di->temp_C;
573		break;
574	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
575		val->intval = di->life_sec;
576		break;
577	case POWER_SUPPLY_PROP_CAPACITY:
578		val->intval = di->rem_capacity;
579		break;
580	default:
581		return -EINVAL;
582	}
583
584	return 0;
585}
586
587static int ds2760_battery_set_property(struct power_supply *psy,
588				       enum power_supply_property psp,
589				       const union power_supply_propval *val)
590{
591	struct ds2760_device_info *di = power_supply_get_drvdata(psy);
592
593	switch (psp) {
594	case POWER_SUPPLY_PROP_CHARGE_FULL:
595		/* the interface counts in uAh, convert the value */
596		ds2760_battery_write_active_full(di, val->intval / 1000L);
597		break;
598
599	case POWER_SUPPLY_PROP_CHARGE_NOW:
600		/* ds2760_battery_set_current_accum() does the conversion */
601		ds2760_battery_set_current_accum(di, val->intval);
602		break;
603
604	default:
605		return -EPERM;
606	}
607
608	return 0;
609}
610
611static int ds2760_battery_property_is_writeable(struct power_supply *psy,
612						enum power_supply_property psp)
613{
614	switch (psp) {
615	case POWER_SUPPLY_PROP_CHARGE_FULL:
616	case POWER_SUPPLY_PROP_CHARGE_NOW:
617		return 1;
618
619	default:
620		break;
621	}
622
623	return 0;
624}
625
626static enum power_supply_property ds2760_battery_props[] = {
627	POWER_SUPPLY_PROP_STATUS,
628	POWER_SUPPLY_PROP_VOLTAGE_NOW,
629	POWER_SUPPLY_PROP_CURRENT_NOW,
630	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
631	POWER_SUPPLY_PROP_CHARGE_FULL,
632	POWER_SUPPLY_PROP_CHARGE_EMPTY,
633	POWER_SUPPLY_PROP_CHARGE_NOW,
634	POWER_SUPPLY_PROP_TEMP,
635	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
636	POWER_SUPPLY_PROP_CAPACITY,
637};
638
639static int ds2760_pm_notifier(struct notifier_block *notifier,
640			      unsigned long pm_event,
641			      void *unused)
642{
643	struct ds2760_device_info *di =
644		container_of(notifier, struct ds2760_device_info, pm_notifier);
645
646	switch (pm_event) {
647	case PM_HIBERNATION_PREPARE:
648	case PM_SUSPEND_PREPARE:
649		di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
650		break;
651
652	case PM_POST_RESTORE:
653	case PM_POST_HIBERNATION:
654	case PM_POST_SUSPEND:
655		di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
656		power_supply_changed(di->bat);
657		mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
658
659		break;
660
661	case PM_RESTORE_PREPARE:
662	default:
663		break;
664	}
665
666	return NOTIFY_DONE;
667}
668
669static int w1_ds2760_add_slave(struct w1_slave *sl)
670{
671	struct power_supply_config psy_cfg = {};
672	struct ds2760_device_info *di;
673	struct device *dev = &sl->dev;
674	int retval = 0;
675	char name[32];
676	char status;
677
678	di = devm_kzalloc(dev, sizeof(*di), GFP_KERNEL);
679	if (!di) {
680		retval = -ENOMEM;
681		goto di_alloc_failed;
682	}
683
684	snprintf(name, sizeof(name), "ds2760-battery.%d", dev->id);
685
686	di->dev				= dev;
687	di->bat_desc.name		= name;
688	di->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
689	di->bat_desc.properties		= ds2760_battery_props;
690	di->bat_desc.num_properties	= ARRAY_SIZE(ds2760_battery_props);
691	di->bat_desc.get_property	= ds2760_battery_get_property;
692	di->bat_desc.set_property	= ds2760_battery_set_property;
693	di->bat_desc.property_is_writeable =
694				  ds2760_battery_property_is_writeable;
695	di->bat_desc.set_charged	= ds2760_battery_set_charged;
696	di->bat_desc.external_power_changed =
697				  ds2760_battery_external_power_changed;
698
699	psy_cfg.drv_data = di;
700
701	if (dev->of_node) {
702		u32 tmp;
703
704		psy_cfg.of_node = dev->of_node;
705
706		if (!of_property_read_bool(dev->of_node, "maxim,pmod-enabled"))
707			pmod_enabled = true;
708
709		if (!of_property_read_u32(dev->of_node,
710					  "maxim,cache-time-ms", &tmp))
711			cache_time = tmp;
712
713		if (!of_property_read_u32(dev->of_node,
714					  "rated-capacity-microamp-hours",
715					  &tmp))
716			rated_capacity = tmp / 10; /* property is in mAh */
717	}
718
719	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
720
721	sl->family_data = di;
722
723	/* enable sleep mode feature */
724	ds2760_battery_read_status(di);
725	status = di->raw[DS2760_STATUS_REG];
726	if (pmod_enabled)
727		status |= DS2760_STATUS_PMOD;
728	else
729		status &= ~DS2760_STATUS_PMOD;
730
731	ds2760_battery_write_status(di, status);
732
733	/* set rated capacity from module param or device tree */
734	if (rated_capacity)
735		ds2760_battery_write_rated_capacity(di, rated_capacity);
736
737	/* set current accumulator if given as parameter.
738	 * this should only be done for bootstrapping the value */
739	if (current_accum)
740		ds2760_battery_set_current_accum(di, current_accum);
741
742	di->bat = devm_power_supply_register(dev, &di->bat_desc, &psy_cfg);
743	if (IS_ERR(di->bat)) {
744		dev_err(di->dev, "failed to register battery\n");
745		retval = PTR_ERR(di->bat);
746		goto batt_failed;
747	}
748
749	INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
750	INIT_DELAYED_WORK(&di->set_charged_work,
751			  ds2760_battery_set_charged_work);
752	di->monitor_wqueue = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
753	if (!di->monitor_wqueue) {
754		retval = -ESRCH;
755		goto workqueue_failed;
756	}
757	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
758
759	di->pm_notifier.notifier_call = ds2760_pm_notifier;
760	register_pm_notifier(&di->pm_notifier);
761
762	goto success;
763
764workqueue_failed:
765batt_failed:
766di_alloc_failed:
767success:
768	return retval;
769}
770
771static void w1_ds2760_remove_slave(struct w1_slave *sl)
772{
773	struct ds2760_device_info *di = sl->family_data;
774
775	unregister_pm_notifier(&di->pm_notifier);
776	cancel_delayed_work_sync(&di->monitor_work);
777	cancel_delayed_work_sync(&di->set_charged_work);
778	destroy_workqueue(di->monitor_wqueue);
779}
780
781#ifdef CONFIG_OF
782static const struct of_device_id w1_ds2760_of_ids[] = {
783	{ .compatible = "maxim,ds2760" },
784	{}
785};
786#endif
787
788static const struct w1_family_ops w1_ds2760_fops = {
789	.add_slave	= w1_ds2760_add_slave,
790	.remove_slave	= w1_ds2760_remove_slave,
791	.groups		= w1_ds2760_groups,
792};
793
794static struct w1_family w1_ds2760_family = {
795	.fid		= W1_FAMILY_DS2760,
796	.fops		= &w1_ds2760_fops,
797	.of_match_table	= of_match_ptr(w1_ds2760_of_ids),
798};
799module_w1_family(w1_ds2760_family);
800
801MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
802	      "Matt Reimer <mreimer@vpop.net>, "
803	      "Anton Vorontsov <cbou@mail.ru>");
804MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
805MODULE_LICENSE("GPL");
806MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));
807