gro: Allow tunnel stacking in the case of FOU/GUE
[linux/fpc-iii.git] / drivers / power / ds2760_battery.c
blob80f73ccb77ab707b56614e44c66d84d60c143b0e
1 /*
2 * Driver for batteries with DS2760 chips inside.
4 * Copyright © 2007 Anton Vorontsov
5 * 2004-2007 Matt Reimer
6 * 2004 Szabolcs Gyurko
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.
12 * Author: Anton Vorontsov <cbou@mail.ru>
13 * February 2007
15 * Matt Reimer <mreimer@vpop.net>
16 * April 2004, 2005, 2007
18 * Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
19 * September 2004
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>
31 #include "../w1/w1.h"
32 #include "../w1/slaves/w1_ds2760.h"
34 struct ds2760_device_info {
35 struct device *dev;
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_* */
55 int full_counter;
56 struct power_supply *bat;
57 struct power_supply_desc bat_desc;
58 struct device *w1_dev;
59 struct workqueue_struct *monitor_wqueue;
60 struct delayed_work monitor_work;
61 struct delayed_work set_charged_work;
64 static unsigned int cache_time = 1000;
65 module_param(cache_time, uint, 0644);
66 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
68 static bool pmod_enabled;
69 module_param(pmod_enabled, bool, 0644);
70 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
72 static unsigned int rated_capacity;
73 module_param(rated_capacity, uint, 0644);
74 MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
76 static unsigned int current_accum;
77 module_param(current_accum, uint, 0644);
78 MODULE_PARM_DESC(current_accum, "current accumulator value");
80 /* Some batteries have their rated capacity stored a N * 10 mAh, while
81 * others use an index into this table. */
82 static int rated_capacities[] = {
84 920, /* Samsung */
85 920, /* BYD */
86 920, /* Lishen */
87 920, /* NEC */
88 1440, /* Samsung */
89 1440, /* BYD */
90 #ifdef CONFIG_MACH_H4700
91 1800, /* HP iPAQ hx4700 3.7V 1800mAh (359113-001) */
92 #else
93 1440, /* Lishen */
94 #endif
95 1440, /* NEC */
96 2880, /* Samsung */
97 2880, /* BYD */
98 2880, /* Lishen */
99 2880, /* NEC */
100 #ifdef CONFIG_MACH_H4700
102 3600, /* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
103 #endif
106 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
107 * temp is in Celsius */
108 static int battery_interpolate(int array[], int temp)
110 int index, dt;
112 if (temp <= 0)
113 return array[0];
114 if (temp >= 40)
115 return array[4];
117 index = temp / 10;
118 dt = temp % 10;
120 return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
123 static int ds2760_battery_read_status(struct ds2760_device_info *di)
125 int ret, i, start, count, scale[5];
127 if (di->update_time && time_before(jiffies, di->update_time +
128 msecs_to_jiffies(cache_time)))
129 return 0;
131 /* The first time we read the entire contents of SRAM/EEPROM,
132 * but after that we just read the interesting bits that change. */
133 if (di->update_time == 0) {
134 start = 0;
135 count = DS2760_DATA_SIZE;
136 } else {
137 start = DS2760_VOLTAGE_MSB;
138 count = DS2760_TEMP_LSB - start + 1;
141 ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
142 if (ret != count) {
143 dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
144 di->w1_dev);
145 return 1;
148 di->update_time = jiffies;
150 /* DS2760 reports voltage in units of 4.88mV, but the battery class
151 * reports in units of uV, so convert by multiplying by 4880. */
152 di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
153 (di->raw[DS2760_VOLTAGE_LSB] >> 5);
154 di->voltage_uV = di->voltage_raw * 4880;
156 /* DS2760 reports current in signed units of 0.625mA, but the battery
157 * class reports in units of µA, so convert by multiplying by 625. */
158 di->current_raw =
159 (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
160 (di->raw[DS2760_CURRENT_LSB] >> 3);
161 di->current_uA = di->current_raw * 625;
163 /* DS2760 reports accumulated current in signed units of 0.25mAh. */
164 di->accum_current_raw =
165 (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
166 di->raw[DS2760_CURRENT_ACCUM_LSB];
167 di->accum_current_uAh = di->accum_current_raw * 250;
169 /* DS2760 reports temperature in signed units of 0.125°C, but the
170 * battery class reports in units of 1/10 °C, so we convert by
171 * multiplying by .125 * 10 = 1.25. */
172 di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
173 (di->raw[DS2760_TEMP_LSB] >> 5);
174 di->temp_C = di->temp_raw + (di->temp_raw / 4);
176 /* At least some battery monitors (e.g. HP iPAQ) store the battery's
177 * maximum rated capacity. */
178 if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
179 di->rated_capacity = rated_capacities[
180 (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
181 else
182 di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
184 di->rated_capacity *= 1000; /* convert to µAh */
186 /* Calculate the full level at the present temperature. */
187 di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
188 di->raw[DS2760_ACTIVE_FULL + 1];
190 /* If the full_active_uAh value is not given, fall back to the rated
191 * capacity. This is likely to happen when chips are not part of the
192 * battery pack and is therefore not bootstrapped. */
193 if (di->full_active_uAh == 0)
194 di->full_active_uAh = di->rated_capacity / 1000L;
196 scale[0] = di->full_active_uAh;
197 for (i = 1; i < 5; i++)
198 scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
200 di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
201 di->full_active_uAh *= 1000; /* convert to µAh */
203 /* Calculate the empty level at the present temperature. */
204 scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
205 for (i = 3; i >= 0; i--)
206 scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
208 di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
209 di->empty_uAh *= 1000; /* convert to µAh */
211 if (di->full_active_uAh == di->empty_uAh)
212 di->rem_capacity = 0;
213 else
214 /* From Maxim Application Note 131: remaining capacity =
215 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
216 di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
217 (di->full_active_uAh - di->empty_uAh);
219 if (di->rem_capacity < 0)
220 di->rem_capacity = 0;
221 if (di->rem_capacity > 100)
222 di->rem_capacity = 100;
224 if (di->current_uA < -100L)
225 di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
226 / (di->current_uA / 100L);
227 else
228 di->life_sec = 0;
230 return 0;
233 static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
234 unsigned int acr_val)
236 unsigned char acr[2];
238 /* acr is in units of 0.25 mAh */
239 acr_val *= 4L;
240 acr_val /= 1000;
242 acr[0] = acr_val >> 8;
243 acr[1] = acr_val & 0xff;
245 if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
246 dev_warn(di->dev, "ACR write failed\n");
249 static void ds2760_battery_update_status(struct ds2760_device_info *di)
251 int old_charge_status = di->charge_status;
253 ds2760_battery_read_status(di);
255 if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
256 di->full_counter = 0;
258 if (power_supply_am_i_supplied(di->bat)) {
259 if (di->current_uA > 10000) {
260 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
261 di->full_counter = 0;
262 } else if (di->current_uA < -5000) {
263 if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
264 dev_notice(di->dev, "not enough power to "
265 "charge\n");
266 di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
267 di->full_counter = 0;
268 } else if (di->current_uA < 10000 &&
269 di->charge_status != POWER_SUPPLY_STATUS_FULL) {
271 /* Don't consider the battery to be full unless
272 * we've seen the current < 10 mA at least two
273 * consecutive times. */
275 di->full_counter++;
277 if (di->full_counter < 2) {
278 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
279 } else {
280 di->charge_status = POWER_SUPPLY_STATUS_FULL;
281 ds2760_battery_set_current_accum(di,
282 di->full_active_uAh);
285 } else {
286 di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
287 di->full_counter = 0;
290 if (di->charge_status != old_charge_status)
291 power_supply_changed(di->bat);
294 static void ds2760_battery_write_status(struct ds2760_device_info *di,
295 char status)
297 if (status == di->raw[DS2760_STATUS_REG])
298 return;
300 w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
301 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
302 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
305 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
306 unsigned char rated_capacity)
308 if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
309 return;
311 w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
312 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
313 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
316 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
317 int active_full)
319 unsigned char tmp[2] = {
320 active_full >> 8,
321 active_full & 0xff
324 if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
325 tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
326 return;
328 w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
329 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
330 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
332 /* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
333 * values won't be read back by ds2760_battery_read_status() */
334 di->raw[DS2760_ACTIVE_FULL] = tmp[0];
335 di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
338 static void ds2760_battery_work(struct work_struct *work)
340 struct ds2760_device_info *di = container_of(work,
341 struct ds2760_device_info, monitor_work.work);
342 const int interval = HZ * 60;
344 dev_dbg(di->dev, "%s\n", __func__);
346 ds2760_battery_update_status(di);
347 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
350 static void ds2760_battery_external_power_changed(struct power_supply *psy)
352 struct ds2760_device_info *di = power_supply_get_drvdata(psy);
354 dev_dbg(di->dev, "%s\n", __func__);
356 mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
360 static void ds2760_battery_set_charged_work(struct work_struct *work)
362 char bias;
363 struct ds2760_device_info *di = container_of(work,
364 struct ds2760_device_info, set_charged_work.work);
366 dev_dbg(di->dev, "%s\n", __func__);
368 ds2760_battery_read_status(di);
370 /* When we get notified by external circuitry that the battery is
371 * considered fully charged now, we know that there is no current
372 * flow any more. However, the ds2760's internal current meter is
373 * too inaccurate to rely on - spec say something ~15% failure.
374 * Hence, we use the current offset bias register to compensate
375 * that error.
378 if (!power_supply_am_i_supplied(di->bat))
379 return;
381 bias = (signed char) di->current_raw +
382 (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
384 dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
386 w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
387 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
388 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
390 /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
391 * value won't be read back by ds2760_battery_read_status() */
392 di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
395 static void ds2760_battery_set_charged(struct power_supply *psy)
397 struct ds2760_device_info *di = power_supply_get_drvdata(psy);
399 /* postpone the actual work by 20 secs. This is for debouncing GPIO
400 * signals and to let the current value settle. See AN4188. */
401 mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
404 static int ds2760_battery_get_property(struct power_supply *psy,
405 enum power_supply_property psp,
406 union power_supply_propval *val)
408 struct ds2760_device_info *di = power_supply_get_drvdata(psy);
410 switch (psp) {
411 case POWER_SUPPLY_PROP_STATUS:
412 val->intval = di->charge_status;
413 return 0;
414 default:
415 break;
418 ds2760_battery_read_status(di);
420 switch (psp) {
421 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
422 val->intval = di->voltage_uV;
423 break;
424 case POWER_SUPPLY_PROP_CURRENT_NOW:
425 val->intval = di->current_uA;
426 break;
427 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
428 val->intval = di->rated_capacity;
429 break;
430 case POWER_SUPPLY_PROP_CHARGE_FULL:
431 val->intval = di->full_active_uAh;
432 break;
433 case POWER_SUPPLY_PROP_CHARGE_EMPTY:
434 val->intval = di->empty_uAh;
435 break;
436 case POWER_SUPPLY_PROP_CHARGE_NOW:
437 val->intval = di->accum_current_uAh;
438 break;
439 case POWER_SUPPLY_PROP_TEMP:
440 val->intval = di->temp_C;
441 break;
442 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
443 val->intval = di->life_sec;
444 break;
445 case POWER_SUPPLY_PROP_CAPACITY:
446 val->intval = di->rem_capacity;
447 break;
448 default:
449 return -EINVAL;
452 return 0;
455 static int ds2760_battery_set_property(struct power_supply *psy,
456 enum power_supply_property psp,
457 const union power_supply_propval *val)
459 struct ds2760_device_info *di = power_supply_get_drvdata(psy);
461 switch (psp) {
462 case POWER_SUPPLY_PROP_CHARGE_FULL:
463 /* the interface counts in uAh, convert the value */
464 ds2760_battery_write_active_full(di, val->intval / 1000L);
465 break;
467 case POWER_SUPPLY_PROP_CHARGE_NOW:
468 /* ds2760_battery_set_current_accum() does the conversion */
469 ds2760_battery_set_current_accum(di, val->intval);
470 break;
472 default:
473 return -EPERM;
476 return 0;
479 static int ds2760_battery_property_is_writeable(struct power_supply *psy,
480 enum power_supply_property psp)
482 switch (psp) {
483 case POWER_SUPPLY_PROP_CHARGE_FULL:
484 case POWER_SUPPLY_PROP_CHARGE_NOW:
485 return 1;
487 default:
488 break;
491 return 0;
494 static enum power_supply_property ds2760_battery_props[] = {
495 POWER_SUPPLY_PROP_STATUS,
496 POWER_SUPPLY_PROP_VOLTAGE_NOW,
497 POWER_SUPPLY_PROP_CURRENT_NOW,
498 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
499 POWER_SUPPLY_PROP_CHARGE_FULL,
500 POWER_SUPPLY_PROP_CHARGE_EMPTY,
501 POWER_SUPPLY_PROP_CHARGE_NOW,
502 POWER_SUPPLY_PROP_TEMP,
503 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
504 POWER_SUPPLY_PROP_CAPACITY,
507 static int ds2760_battery_probe(struct platform_device *pdev)
509 struct power_supply_config psy_cfg = {};
510 char status;
511 int retval = 0;
512 struct ds2760_device_info *di;
514 di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
515 if (!di) {
516 retval = -ENOMEM;
517 goto di_alloc_failed;
520 platform_set_drvdata(pdev, di);
522 di->dev = &pdev->dev;
523 di->w1_dev = pdev->dev.parent;
524 di->bat_desc.name = dev_name(&pdev->dev);
525 di->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
526 di->bat_desc.properties = ds2760_battery_props;
527 di->bat_desc.num_properties = ARRAY_SIZE(ds2760_battery_props);
528 di->bat_desc.get_property = ds2760_battery_get_property;
529 di->bat_desc.set_property = ds2760_battery_set_property;
530 di->bat_desc.property_is_writeable =
531 ds2760_battery_property_is_writeable;
532 di->bat_desc.set_charged = ds2760_battery_set_charged;
533 di->bat_desc.external_power_changed =
534 ds2760_battery_external_power_changed;
536 psy_cfg.drv_data = di;
538 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
540 /* enable sleep mode feature */
541 ds2760_battery_read_status(di);
542 status = di->raw[DS2760_STATUS_REG];
543 if (pmod_enabled)
544 status |= DS2760_STATUS_PMOD;
545 else
546 status &= ~DS2760_STATUS_PMOD;
548 ds2760_battery_write_status(di, status);
550 /* set rated capacity from module param */
551 if (rated_capacity)
552 ds2760_battery_write_rated_capacity(di, rated_capacity);
554 /* set current accumulator if given as parameter.
555 * this should only be done for bootstrapping the value */
556 if (current_accum)
557 ds2760_battery_set_current_accum(di, current_accum);
559 di->bat = power_supply_register(&pdev->dev, &di->bat_desc, &psy_cfg);
560 if (IS_ERR(di->bat)) {
561 dev_err(di->dev, "failed to register battery\n");
562 retval = PTR_ERR(di->bat);
563 goto batt_failed;
566 INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
567 INIT_DELAYED_WORK(&di->set_charged_work,
568 ds2760_battery_set_charged_work);
569 di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
570 if (!di->monitor_wqueue) {
571 retval = -ESRCH;
572 goto workqueue_failed;
574 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
576 goto success;
578 workqueue_failed:
579 power_supply_unregister(di->bat);
580 batt_failed:
581 di_alloc_failed:
582 success:
583 return retval;
586 static int ds2760_battery_remove(struct platform_device *pdev)
588 struct ds2760_device_info *di = platform_get_drvdata(pdev);
590 cancel_delayed_work_sync(&di->monitor_work);
591 cancel_delayed_work_sync(&di->set_charged_work);
592 destroy_workqueue(di->monitor_wqueue);
593 power_supply_unregister(di->bat);
595 return 0;
598 #ifdef CONFIG_PM
600 static int ds2760_battery_suspend(struct platform_device *pdev,
601 pm_message_t state)
603 struct ds2760_device_info *di = platform_get_drvdata(pdev);
605 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
607 return 0;
610 static int ds2760_battery_resume(struct platform_device *pdev)
612 struct ds2760_device_info *di = platform_get_drvdata(pdev);
614 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
615 power_supply_changed(di->bat);
617 mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
619 return 0;
622 #else
624 #define ds2760_battery_suspend NULL
625 #define ds2760_battery_resume NULL
627 #endif /* CONFIG_PM */
629 MODULE_ALIAS("platform:ds2760-battery");
631 static struct platform_driver ds2760_battery_driver = {
632 .driver = {
633 .name = "ds2760-battery",
635 .probe = ds2760_battery_probe,
636 .remove = ds2760_battery_remove,
637 .suspend = ds2760_battery_suspend,
638 .resume = ds2760_battery_resume,
641 module_platform_driver(ds2760_battery_driver);
643 MODULE_LICENSE("GPL");
644 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
645 "Matt Reimer <mreimer@vpop.net>, "
646 "Anton Vorontsov <cbou@mail.ru>");
647 MODULE_DESCRIPTION("ds2760 battery driver");