ds2760_battery.c revision 86e6c6bd9b70260fc5bc9fdfa2e5b4dfd8fe545c
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 34struct 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 63static unsigned int cache_time = 1000; 64module_param(cache_time, uint, 0644); 65MODULE_PARM_DESC(cache_time, "cache time in milliseconds"); 66 67static unsigned int pmod_enabled; 68module_param(pmod_enabled, bool, 0644); 69MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit"); 70 71static unsigned int rated_capacity; 72module_param(rated_capacity, uint, 0644); 73MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index"); 74 75static unsigned int current_accum; 76module_param(current_accum, uint, 0644); 77MODULE_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. */ 81static 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 */ 107static 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 122static 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 232static 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 248static 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 293static 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 304static 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 315static 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 337static 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 352static 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 cancel_delayed_work(&di->monitor_work); 359 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10); 360} 361 362 363static void ds2760_battery_set_charged_work(struct work_struct *work) 364{ 365 char bias; 366 struct ds2760_device_info *di = container_of(work, 367 struct ds2760_device_info, set_charged_work.work); 368 369 dev_dbg(di->dev, "%s\n", __func__); 370 371 ds2760_battery_read_status(di); 372 373 /* When we get notified by external circuitry that the battery is 374 * considered fully charged now, we know that there is no current 375 * flow any more. However, the ds2760's internal current meter is 376 * too inaccurate to rely on - spec say something ~15% failure. 377 * Hence, we use the current offset bias register to compensate 378 * that error. 379 */ 380 381 if (!power_supply_am_i_supplied(&di->bat)) 382 return; 383 384 bias = (signed char) di->current_raw + 385 (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS]; 386 387 dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias); 388 389 w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1); 390 w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); 391 w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1); 392 393 /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS 394 * value won't be read back by ds2760_battery_read_status() */ 395 di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias; 396} 397 398static void ds2760_battery_set_charged(struct power_supply *psy) 399{ 400 struct ds2760_device_info *di = to_ds2760_device_info(psy); 401 402 /* postpone the actual work by 20 secs. This is for debouncing GPIO 403 * signals and to let the current value settle. See AN4188. */ 404 cancel_delayed_work(&di->set_charged_work); 405 queue_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20); 406} 407 408static int ds2760_battery_get_property(struct power_supply *psy, 409 enum power_supply_property psp, 410 union power_supply_propval *val) 411{ 412 struct ds2760_device_info *di = to_ds2760_device_info(psy); 413 414 switch (psp) { 415 case POWER_SUPPLY_PROP_STATUS: 416 val->intval = di->charge_status; 417 return 0; 418 default: 419 break; 420 } 421 422 ds2760_battery_read_status(di); 423 424 switch (psp) { 425 case POWER_SUPPLY_PROP_VOLTAGE_NOW: 426 val->intval = di->voltage_uV; 427 break; 428 case POWER_SUPPLY_PROP_CURRENT_NOW: 429 val->intval = di->current_uA; 430 break; 431 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: 432 val->intval = di->rated_capacity; 433 break; 434 case POWER_SUPPLY_PROP_CHARGE_FULL: 435 val->intval = di->full_active_uAh; 436 break; 437 case POWER_SUPPLY_PROP_CHARGE_EMPTY: 438 val->intval = di->empty_uAh; 439 break; 440 case POWER_SUPPLY_PROP_CHARGE_NOW: 441 val->intval = di->accum_current_uAh; 442 break; 443 case POWER_SUPPLY_PROP_TEMP: 444 val->intval = di->temp_C; 445 break; 446 case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: 447 val->intval = di->life_sec; 448 break; 449 case POWER_SUPPLY_PROP_CAPACITY: 450 val->intval = di->rem_capacity; 451 break; 452 default: 453 return -EINVAL; 454 } 455 456 return 0; 457} 458 459static int ds2760_battery_set_property(struct power_supply *psy, 460 enum power_supply_property psp, 461 const union power_supply_propval *val) 462{ 463 struct ds2760_device_info *di = to_ds2760_device_info(psy); 464 465 switch (psp) { 466 case POWER_SUPPLY_PROP_CHARGE_FULL: 467 /* the interface counts in uAh, convert the value */ 468 ds2760_battery_write_active_full(di, val->intval / 1000L); 469 break; 470 471 case POWER_SUPPLY_PROP_CHARGE_NOW: 472 /* ds2760_battery_set_current_accum() does the conversion */ 473 ds2760_battery_set_current_accum(di, val->intval); 474 break; 475 476 default: 477 return -EPERM; 478 } 479 480 return 0; 481} 482 483static int ds2760_battery_property_is_writeable(struct power_supply *psy, 484 enum power_supply_property psp) 485{ 486 switch (psp) { 487 case POWER_SUPPLY_PROP_CHARGE_FULL: 488 case POWER_SUPPLY_PROP_CHARGE_NOW: 489 return 1; 490 491 default: 492 break; 493 } 494 495 return 0; 496} 497 498static enum power_supply_property ds2760_battery_props[] = { 499 POWER_SUPPLY_PROP_STATUS, 500 POWER_SUPPLY_PROP_VOLTAGE_NOW, 501 POWER_SUPPLY_PROP_CURRENT_NOW, 502 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 503 POWER_SUPPLY_PROP_CHARGE_FULL, 504 POWER_SUPPLY_PROP_CHARGE_EMPTY, 505 POWER_SUPPLY_PROP_CHARGE_NOW, 506 POWER_SUPPLY_PROP_TEMP, 507 POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, 508 POWER_SUPPLY_PROP_CAPACITY, 509}; 510 511static int ds2760_battery_probe(struct platform_device *pdev) 512{ 513 char status; 514 int retval = 0; 515 struct ds2760_device_info *di; 516 517 di = kzalloc(sizeof(*di), GFP_KERNEL); 518 if (!di) { 519 retval = -ENOMEM; 520 goto di_alloc_failed; 521 } 522 523 platform_set_drvdata(pdev, di); 524 525 di->dev = &pdev->dev; 526 di->w1_dev = pdev->dev.parent; 527 di->bat.name = dev_name(&pdev->dev); 528 di->bat.type = POWER_SUPPLY_TYPE_BATTERY; 529 di->bat.properties = ds2760_battery_props; 530 di->bat.num_properties = ARRAY_SIZE(ds2760_battery_props); 531 di->bat.get_property = ds2760_battery_get_property; 532 di->bat.set_property = ds2760_battery_set_property; 533 di->bat.property_is_writeable = 534 ds2760_battery_property_is_writeable; 535 di->bat.set_charged = ds2760_battery_set_charged; 536 di->bat.external_power_changed = 537 ds2760_battery_external_power_changed; 538 539 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; 540 541 /* enable sleep mode feature */ 542 ds2760_battery_read_status(di); 543 status = di->raw[DS2760_STATUS_REG]; 544 if (pmod_enabled) 545 status |= DS2760_STATUS_PMOD; 546 else 547 status &= ~DS2760_STATUS_PMOD; 548 549 ds2760_battery_write_status(di, status); 550 551 /* set rated capacity from module param */ 552 if (rated_capacity) 553 ds2760_battery_write_rated_capacity(di, rated_capacity); 554 555 /* set current accumulator if given as parameter. 556 * this should only be done for bootstrapping the value */ 557 if (current_accum) 558 ds2760_battery_set_current_accum(di, current_accum); 559 560 retval = power_supply_register(&pdev->dev, &di->bat); 561 if (retval) { 562 dev_err(di->dev, "failed to register battery\n"); 563 goto batt_failed; 564 } 565 566 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; 573 } 574 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1); 575 576 goto success; 577 578workqueue_failed: 579 power_supply_unregister(&di->bat); 580batt_failed: 581 kfree(di); 582di_alloc_failed: 583success: 584 return retval; 585} 586 587static int ds2760_battery_remove(struct platform_device *pdev) 588{ 589 struct ds2760_device_info *di = platform_get_drvdata(pdev); 590 591 cancel_delayed_work_sync(&di->monitor_work); 592 cancel_delayed_work_sync(&di->set_charged_work); 593 destroy_workqueue(di->monitor_wqueue); 594 power_supply_unregister(&di->bat); 595 kfree(di); 596 597 return 0; 598} 599 600#ifdef CONFIG_PM 601 602static int ds2760_battery_suspend(struct platform_device *pdev, 603 pm_message_t state) 604{ 605 struct ds2760_device_info *di = platform_get_drvdata(pdev); 606 607 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; 608 609 return 0; 610} 611 612static int ds2760_battery_resume(struct platform_device *pdev) 613{ 614 struct ds2760_device_info *di = platform_get_drvdata(pdev); 615 616 di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN; 617 power_supply_changed(&di->bat); 618 619 cancel_delayed_work(&di->monitor_work); 620 queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ); 621 622 return 0; 623} 624 625#else 626 627#define ds2760_battery_suspend NULL 628#define ds2760_battery_resume NULL 629 630#endif /* CONFIG_PM */ 631 632MODULE_ALIAS("platform:ds2760-battery"); 633 634static struct platform_driver ds2760_battery_driver = { 635 .driver = { 636 .name = "ds2760-battery", 637 }, 638 .probe = ds2760_battery_probe, 639 .remove = ds2760_battery_remove, 640 .suspend = ds2760_battery_suspend, 641 .resume = ds2760_battery_resume, 642}; 643 644static int __init ds2760_battery_init(void) 645{ 646 return platform_driver_register(&ds2760_battery_driver); 647} 648 649static void __exit ds2760_battery_exit(void) 650{ 651 platform_driver_unregister(&ds2760_battery_driver); 652} 653 654module_init(ds2760_battery_init); 655module_exit(ds2760_battery_exit); 656 657MODULE_LICENSE("GPL"); 658MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, " 659 "Matt Reimer <mreimer@vpop.net>, " 660 "Anton Vorontsov <cbou@mail.ru>"); 661MODULE_DESCRIPTION("ds2760 battery driver"); 662