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Linux 2.6.31.6
[linux-2.6/verdex.git] / drivers / power / ds2760_battery.c
blob520b5c49ff3049275dbeada16c80b93135cf47ea
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/platform_device.h>
28 #include <linux/power_supply.h>
29
30 #include "../w1/w1.h"
31 #include "../w1/slaves/w1_ds2760.h"
32
33 struct ds2760_device_info {
34 struct device *dev;
35
36 /* DS2760 data, valid after calling ds2760_battery_read_status() */
37 unsigned long update_time; /* jiffies when data read */
38 char raw[DS2760_DATA_SIZE]; /* raw DS2760 data */
39 int voltage_raw; /* units of 4.88 mV */
40 int voltage_uV; /* units of µV */
41 int current_raw; /* units of 0.625 mA */
42 int current_uA; /* units of µA */
43 int accum_current_raw; /* units of 0.25 mAh */
44 int accum_current_uAh; /* units of µAh */
45 int temp_raw; /* units of 0.125 °C */
46 int temp_C; /* units of 0.1 °C */
47 int rated_capacity; /* units of µAh */
48 int rem_capacity; /* percentage */
49 int full_active_uAh; /* units of µAh */
50 int empty_uAh; /* units of µAh */
51 int life_sec; /* units of seconds */
52 int charge_status; /* POWER_SUPPLY_STATUS_* */
53
54 int full_counter;
55 struct power_supply bat;
56 struct device *w1_dev;
57 struct workqueue_struct *monitor_wqueue;
58 struct delayed_work monitor_work;
59 };
60
61 static unsigned int cache_time = 1000;
62 module_param(cache_time, uint, 0644);
63 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
64
65 static unsigned int pmod_enabled;
66 module_param(pmod_enabled, bool, 0644);
67 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
68
69 /* Some batteries have their rated capacity stored a N * 10 mAh, while
70 * others use an index into this table. */
71 static int rated_capacities[] = {
72 0,
73 920, /* Samsung */
74 920, /* BYD */
75 920, /* Lishen */
76 920, /* NEC */
77 1440, /* Samsung */
78 1440, /* BYD */
79 1440, /* Lishen */
80 1440, /* NEC */
81 2880, /* Samsung */
82 2880, /* BYD */
83 2880, /* Lishen */
84 2880 /* NEC */
85 };
86
87 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
88 * temp is in Celsius */
89 static int battery_interpolate(int array[], int temp)
90 {
91 int index, dt;
92
93 if (temp <= 0)
94 return array[0];
95 if (temp >= 40)
96 return array[4];
97
98 index = temp / 10;
99 dt = temp % 10;
100
101 return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
102 }
103
104 static int ds2760_battery_read_status(struct ds2760_device_info *di)
105 {
106 int ret, i, start, count, scale[5];
107
108 if (di->update_time && time_before(jiffies, di->update_time +
109 msecs_to_jiffies(cache_time)))
110 return 0;
111
112 /* The first time we read the entire contents of SRAM/EEPROM,
113 * but after that we just read the interesting bits that change. */
114 if (di->update_time == 0) {
115 start = 0;
116 count = DS2760_DATA_SIZE;
117 } else {
118 start = DS2760_VOLTAGE_MSB;
119 count = DS2760_TEMP_LSB - start + 1;
120 }
121
122 ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
123 if (ret != count) {
124 dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
125 di->w1_dev);
126 return 1;
127 }
128
129 di->update_time = jiffies;
130
131 /* DS2760 reports voltage in units of 4.88mV, but the battery class
132 * reports in units of uV, so convert by multiplying by 4880. */
133 di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
134 (di->raw[DS2760_VOLTAGE_LSB] >> 5);
135 di->voltage_uV = di->voltage_raw * 4880;
136
137 /* DS2760 reports current in signed units of 0.625mA, but the battery
138 * class reports in units of µA, so convert by multiplying by 625. */
139 di->current_raw =
140 (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
141 (di->raw[DS2760_CURRENT_LSB] >> 3);
142 di->current_uA = di->current_raw * 625;
143
144 /* DS2760 reports accumulated current in signed units of 0.25mAh. */
145 di->accum_current_raw =
146 (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
147 di->raw[DS2760_CURRENT_ACCUM_LSB];
148 di->accum_current_uAh = di->accum_current_raw * 250;
149
150 /* DS2760 reports temperature in signed units of 0.125°C, but the
151 * battery class reports in units of 1/10 °C, so we convert by
152 * multiplying by .125 * 10 = 1.25. */
153 di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
154 (di->raw[DS2760_TEMP_LSB] >> 5);
155 di->temp_C = di->temp_raw + (di->temp_raw / 4);
156
157 /* At least some battery monitors (e.g. HP iPAQ) store the battery's
158 * maximum rated capacity. */
159 if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
160 di->rated_capacity = rated_capacities[
161 (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
162 else
163 di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
164
165 di->rated_capacity *= 1000; /* convert to µAh */
166
167 /* Calculate the full level at the present temperature. */
168 di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
169 di->raw[DS2760_ACTIVE_FULL + 1];
170
171 scale[0] = di->raw[DS2760_ACTIVE_FULL] << 8 |
172 di->raw[DS2760_ACTIVE_FULL + 1];
173 for (i = 1; i < 5; i++)
174 scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 2 + i];
175
176 di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
177 di->full_active_uAh *= 1000; /* convert to µAh */
178
179 /* Calculate the empty level at the present temperature. */
180 scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
181 for (i = 3; i >= 0; i--)
182 scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
183
184 di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
185 di->empty_uAh *= 1000; /* convert to µAh */
186
187 if (di->full_active_uAh == di->empty_uAh)
188 di->rem_capacity = 0;
189 else
190 /* From Maxim Application Note 131: remaining capacity =
191 * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
192 di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
193 (di->full_active_uAh - di->empty_uAh);
194
195 if (di->rem_capacity < 0)
196 di->rem_capacity = 0;
197 if (di->rem_capacity > 100)
198 di->rem_capacity = 100;
199
200 if (di->current_uA)
201 di->life_sec = -((di->accum_current_uAh - di->empty_uAh) *
202 3600L) / di->current_uA;
203 else
204 di->life_sec = 0;
205
206 return 0;
207 }
208
209 static void ds2760_battery_update_status(struct ds2760_device_info *di)
210 {
211 int old_charge_status = di->charge_status;
212
213 ds2760_battery_read_status(di);
214
215 if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
216 di->full_counter = 0;
217
218 if (power_supply_am_i_supplied(&di->bat)) {
219 if (di->current_uA > 10000) {
220 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
221 di->full_counter = 0;
222 } else if (di->current_uA < -5000) {
223 if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
224 dev_notice(di->dev, "not enough power to "
225 "charge\n");
226 di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
227 di->full_counter = 0;
228 } else if (di->current_uA < 10000 &&
229 di->charge_status != POWER_SUPPLY_STATUS_FULL) {
230
231 /* Don't consider the battery to be full unless
232 * we've seen the current < 10 mA at least two
233 * consecutive times. */
234
235 di->full_counter++;
236
237 if (di->full_counter < 2) {
238 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
239 } else {
240 unsigned char acr[2];
241 int acr_val;
242
243 /* acr is in units of 0.25 mAh */
244 acr_val = di->full_active_uAh * 4L / 1000;
245
246 acr[0] = acr_val >> 8;
247 acr[1] = acr_val & 0xff;
248
249 if (w1_ds2760_write(di->w1_dev, acr,
250 DS2760_CURRENT_ACCUM_MSB, 2) < 2)
251 dev_warn(di->dev,
252 "ACR reset failed\n");
253
254 di->charge_status = POWER_SUPPLY_STATUS_FULL;
255 }
256 }
257 } else {
258 di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
259 di->full_counter = 0;
260 }
261
262 if (di->charge_status != old_charge_status)
263 power_supply_changed(&di->bat);
264 }
265
266 static void ds2760_battery_write_status(struct ds2760_device_info *di,
267 char status)
268 {
269 if (status == di->raw[DS2760_STATUS_REG])
270 return;
271
272 w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
273 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
274 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
275 }
276
277 static void ds2760_battery_work(struct work_struct *work)
278 {
279 struct ds2760_device_info *di = container_of(work,
280 struct ds2760_device_info, monitor_work.work);
281 const int interval = HZ * 60;
282
283 dev_dbg(di->dev, "%s\n", __func__);
284
285 ds2760_battery_update_status(di);
286 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
287 }
288
289 #define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
290 bat);
291
292 static void ds2760_battery_external_power_changed(struct power_supply *psy)
293 {
294 struct ds2760_device_info *di = to_ds2760_device_info(psy);
295
296 dev_dbg(di->dev, "%s\n", __func__);
297
298 cancel_delayed_work(&di->monitor_work);
299 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
300 }
301
302 static int ds2760_battery_get_property(struct power_supply *psy,
303 enum power_supply_property psp,
304 union power_supply_propval *val)
305 {
306 struct ds2760_device_info *di = to_ds2760_device_info(psy);
307
308 switch (psp) {
309 case POWER_SUPPLY_PROP_STATUS:
310 val->intval = di->charge_status;
311 return 0;
312 default:
313 break;
314 }
315
316 ds2760_battery_read_status(di);
317
318 switch (psp) {
319 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
320 val->intval = di->voltage_uV;
321 break;
322 case POWER_SUPPLY_PROP_CURRENT_NOW:
323 val->intval = di->current_uA;
324 break;
325 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
326 val->intval = di->rated_capacity;
327 break;
328 case POWER_SUPPLY_PROP_CHARGE_FULL:
329 val->intval = di->full_active_uAh;
330 break;
331 case POWER_SUPPLY_PROP_CHARGE_EMPTY:
332 val->intval = di->empty_uAh;
333 break;
334 case POWER_SUPPLY_PROP_CHARGE_NOW:
335 val->intval = di->accum_current_uAh;
336 break;
337 case POWER_SUPPLY_PROP_TEMP:
338 val->intval = di->temp_C;
339 break;
340 default:
341 return -EINVAL;
342 }
343
344 return 0;
345 }
346
347 static enum power_supply_property ds2760_battery_props[] = {
348 POWER_SUPPLY_PROP_STATUS,
349 POWER_SUPPLY_PROP_VOLTAGE_NOW,
350 POWER_SUPPLY_PROP_CURRENT_NOW,
351 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
352 POWER_SUPPLY_PROP_CHARGE_FULL,
353 POWER_SUPPLY_PROP_CHARGE_EMPTY,
354 POWER_SUPPLY_PROP_CHARGE_NOW,
355 POWER_SUPPLY_PROP_TEMP,
356 };
357
358 static int ds2760_battery_probe(struct platform_device *pdev)
359 {
360 char status;
361 int retval = 0;
362 struct ds2760_device_info *di;
363
364 di = kzalloc(sizeof(*di), GFP_KERNEL);
365 if (!di) {
366 retval = -ENOMEM;
367 goto di_alloc_failed;
368 }
369
370 platform_set_drvdata(pdev, di);
371
372 di->dev = &pdev->dev;
373 di->w1_dev = pdev->dev.parent;
374 di->bat.name = dev_name(&pdev->dev);
375 di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
376 di->bat.properties = ds2760_battery_props;
377 di->bat.num_properties = ARRAY_SIZE(ds2760_battery_props);
378 di->bat.get_property = ds2760_battery_get_property;
379 di->bat.external_power_changed =
380 ds2760_battery_external_power_changed;
381
382 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
383
384 retval = power_supply_register(&pdev->dev, &di->bat);
385 if (retval) {
386 dev_err(di->dev, "failed to register battery\n");
387 goto batt_failed;
388 }
389
390 /* enable sleep mode feature */
391 ds2760_battery_read_status(di);
392 status = di->raw[DS2760_STATUS_REG];
393 if (pmod_enabled)
394 status |= DS2760_STATUS_PMOD;
395 else
396 status &= ~DS2760_STATUS_PMOD;
397
398 ds2760_battery_write_status(di, status);
399
400 INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
401 di->monitor_wqueue = create_singlethread_workqueue(dev_name(&pdev->dev));
402 if (!di->monitor_wqueue) {
403 retval = -ESRCH;
404 goto workqueue_failed;
405 }
406 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
407
408 goto success;
409
410 workqueue_failed:
411 power_supply_unregister(&di->bat);
412 batt_failed:
413 kfree(di);
414 di_alloc_failed:
415 success:
416 return retval;
417 }
418
419 static int ds2760_battery_remove(struct platform_device *pdev)
420 {
421 struct ds2760_device_info *di = platform_get_drvdata(pdev);
422
423 cancel_rearming_delayed_workqueue(di->monitor_wqueue,
424 &di->monitor_work);
425 destroy_workqueue(di->monitor_wqueue);
426 power_supply_unregister(&di->bat);
427
428 return 0;
429 }
430
431 #ifdef CONFIG_PM
432
433 static int ds2760_battery_suspend(struct platform_device *pdev,
434 pm_message_t state)
435 {
436 struct ds2760_device_info *di = platform_get_drvdata(pdev);
437
438 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
439
440 return 0;
441 }
442
443 static int ds2760_battery_resume(struct platform_device *pdev)
444 {
445 struct ds2760_device_info *di = platform_get_drvdata(pdev);
446
447 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
448 power_supply_changed(&di->bat);
449
450 cancel_delayed_work(&di->monitor_work);
451 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
452
453 return 0;
454 }
455
456 #else
457
458 #define ds2760_battery_suspend NULL
459 #define ds2760_battery_resume NULL
460
461 #endif /* CONFIG_PM */
462
463 MODULE_ALIAS("platform:ds2760-battery");
464
465 static struct platform_driver ds2760_battery_driver = {
466 .driver = {
467 .name = "ds2760-battery",
468 },
469 .probe = ds2760_battery_probe,
470 .remove = ds2760_battery_remove,
471 .suspend = ds2760_battery_suspend,
472 .resume = ds2760_battery_resume,
473 };
474
475 static int __init ds2760_battery_init(void)
476 {
477 return platform_driver_register(&ds2760_battery_driver);
478 }
479
480 static void __exit ds2760_battery_exit(void)
481 {
482 platform_driver_unregister(&ds2760_battery_driver);
483 }
484
485 module_init(ds2760_battery_init);
486 module_exit(ds2760_battery_exit);
487
488 MODULE_LICENSE("GPL");
489 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
490 "Matt Reimer <mreimer@vpop.net>, "
491 "Anton Vorontsov <cbou@mail.ru>");
492 MODULE_DESCRIPTION("ds2760 battery driver");
Verdex Pro support