Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux/fpc-iii.git] / drivers / power / ds2760_battery.c
blob85b4e6eca0b1984cc39ea0a3e0d6fbd5614ab543
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 device *w1_dev;
58 struct workqueue_struct *monitor_wqueue;
59 struct delayed_work monitor_work;
60 struct delayed_work set_charged_work;
63 static unsigned int cache_time = 1000;
64 module_param(cache_time, uint, 0644);
65 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
67 static bool pmod_enabled;
68 module_param(pmod_enabled, bool, 0644);
69 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
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");
75 static unsigned int current_accum;
76 module_param(current_accum, uint, 0644);
77 MODULE_PARM_DESC(current_accum, "current accumulator value");
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[] = {
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
101 3600, /* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
102 #endif
105 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
106 * temp is in Celsius */
107 static int battery_interpolate(int array[], int temp)
109 int index, dt;
111 if (temp <= 0)
112 return array[0];
113 if (temp >= 40)
114 return array[4];
116 index = temp / 10;
117 dt = temp % 10;
119 return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
122 static int ds2760_battery_read_status(struct ds2760_device_info *di)
124 int ret, i, start, count, scale[5];
126 if (di->update_time && time_before(jiffies, di->update_time +
127 msecs_to_jiffies(cache_time)))
128 return 0;
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;
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;
147 di->update_time = jiffies;
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;
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;
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;
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);
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;
183 di->rated_capacity *= 1000; /* convert to µAh */
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];
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;
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];
199 di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
200 di->full_active_uAh *= 1000; /* convert to µAh */
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];
207 di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
208 di->empty_uAh *= 1000; /* convert to µAh */
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);
218 if (di->rem_capacity < 0)
219 di->rem_capacity = 0;
220 if (di->rem_capacity > 100)
221 di->rem_capacity = 100;
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;
229 return 0;
232 static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
233 unsigned int acr_val)
235 unsigned char acr[2];
237 /* acr is in units of 0.25 mAh */
238 acr_val *= 4L;
239 acr_val /= 1000;
241 acr[0] = acr_val >> 8;
242 acr[1] = acr_val & 0xff;
244 if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
245 dev_warn(di->dev, "ACR write failed\n");
248 static void ds2760_battery_update_status(struct ds2760_device_info *di)
250 int old_charge_status = di->charge_status;
252 ds2760_battery_read_status(di);
254 if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
255 di->full_counter = 0;
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) {
270 /* Don't consider the battery to be full unless
271 * we've seen the current < 10 mA at least two
272 * consecutive times. */
274 di->full_counter++;
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);
284 } else {
285 di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
286 di->full_counter = 0;
289 if (di->charge_status != old_charge_status)
290 power_supply_changed(&di->bat);
293 static void ds2760_battery_write_status(struct ds2760_device_info *di,
294 char status)
296 if (status == di->raw[DS2760_STATUS_REG])
297 return;
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);
304 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
305 unsigned char rated_capacity)
307 if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
308 return;
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);
315 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
316 int active_full)
318 unsigned char tmp[2] = {
319 active_full >> 8,
320 active_full & 0xff
323 if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
324 tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
325 return;
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);
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];
337 static void ds2760_battery_work(struct work_struct *work)
339 struct ds2760_device_info *di = container_of(work,
340 struct ds2760_device_info, monitor_work.work);
341 const int interval = HZ * 60;
343 dev_dbg(di->dev, "%s\n", __func__);
345 ds2760_battery_update_status(di);
346 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
349 #define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
350 bat);
352 static void ds2760_battery_external_power_changed(struct power_supply *psy)
354 struct ds2760_device_info *di = to_ds2760_device_info(psy);
356 dev_dbg(di->dev, "%s\n", __func__);
358 mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
362 static void ds2760_battery_set_charged_work(struct work_struct *work)
364 char bias;
365 struct ds2760_device_info *di = container_of(work,
366 struct ds2760_device_info, set_charged_work.work);
368 dev_dbg(di->dev, "%s\n", __func__);
370 ds2760_battery_read_status(di);
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.
380 if (!power_supply_am_i_supplied(&di->bat))
381 return;
383 bias = (signed char) di->current_raw +
384 (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
386 dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
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);
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;
397 static void ds2760_battery_set_charged(struct power_supply *psy)
399 struct ds2760_device_info *di = to_ds2760_device_info(psy);
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);
406 static int ds2760_battery_get_property(struct power_supply *psy,
407 enum power_supply_property psp,
408 union power_supply_propval *val)
410 struct ds2760_device_info *di = to_ds2760_device_info(psy);
412 switch (psp) {
413 case POWER_SUPPLY_PROP_STATUS:
414 val->intval = di->charge_status;
415 return 0;
416 default:
417 break;
420 ds2760_battery_read_status(di);
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;
454 return 0;
457 static int ds2760_battery_set_property(struct power_supply *psy,
458 enum power_supply_property psp,
459 const union power_supply_propval *val)
461 struct ds2760_device_info *di = to_ds2760_device_info(psy);
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;
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;
474 default:
475 return -EPERM;
478 return 0;
481 static int ds2760_battery_property_is_writeable(struct power_supply *psy,
482 enum power_supply_property psp)
484 switch (psp) {
485 case POWER_SUPPLY_PROP_CHARGE_FULL:
486 case POWER_SUPPLY_PROP_CHARGE_NOW:
487 return 1;
489 default:
490 break;
493 return 0;
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,
509 static int ds2760_battery_probe(struct platform_device *pdev)
511 char status;
512 int retval = 0;
513 struct ds2760_device_info *di;
515 di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
516 if (!di) {
517 retval = -ENOMEM;
518 goto di_alloc_failed;
521 platform_set_drvdata(pdev, di);
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;
537 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
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;
547 ds2760_battery_write_status(di, status);
549 /* set rated capacity from module param */
550 if (rated_capacity)
551 ds2760_battery_write_rated_capacity(di, rated_capacity);
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);
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;
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;
572 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
574 goto success;
576 workqueue_failed:
577 power_supply_unregister(&di->bat);
578 batt_failed:
579 di_alloc_failed:
580 success:
581 return retval;
584 static int ds2760_battery_remove(struct platform_device *pdev)
586 struct ds2760_device_info *di = platform_get_drvdata(pdev);
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);
593 return 0;
596 #ifdef CONFIG_PM
598 static int ds2760_battery_suspend(struct platform_device *pdev,
599 pm_message_t state)
601 struct ds2760_device_info *di = platform_get_drvdata(pdev);
603 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
605 return 0;
608 static int ds2760_battery_resume(struct platform_device *pdev)
610 struct ds2760_device_info *di = platform_get_drvdata(pdev);
612 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
613 power_supply_changed(&di->bat);
615 mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
617 return 0;
620 #else
622 #define ds2760_battery_suspend NULL
623 #define ds2760_battery_resume NULL
625 #endif /* CONFIG_PM */
627 MODULE_ALIAS("platform:ds2760-battery");
629 static struct platform_driver ds2760_battery_driver = {
630 .driver = {
631 .name = "ds2760-battery",
633 .probe = ds2760_battery_probe,
634 .remove = ds2760_battery_remove,
635 .suspend = ds2760_battery_suspend,
636 .resume = ds2760_battery_resume,
639 module_platform_driver(ds2760_battery_driver);
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");