olpc_battery.c revision 20fd9830ccc685adce65ba89ffc3ca5426a2b064
1/* 2 * Battery driver for One Laptop Per Child board. 3 * 4 * Copyright © 2006-2010 David Woodhouse <dwmw2@infradead.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11#include <linux/kernel.h> 12#include <linux/module.h> 13#include <linux/types.h> 14#include <linux/err.h> 15#include <linux/device.h> 16#include <linux/platform_device.h> 17#include <linux/power_supply.h> 18#include <linux/jiffies.h> 19#include <linux/sched.h> 20#include <asm/olpc.h> 21 22 23#define EC_BAT_VOLTAGE 0x10 /* uint16_t, *9.76/32, mV */ 24#define EC_BAT_CURRENT 0x11 /* int16_t, *15.625/120, mA */ 25#define EC_BAT_ACR 0x12 /* int16_t, *6250/15, µAh */ 26#define EC_BAT_TEMP 0x13 /* uint16_t, *100/256, °C */ 27#define EC_AMB_TEMP 0x14 /* uint16_t, *100/256, °C */ 28#define EC_BAT_STATUS 0x15 /* uint8_t, bitmask */ 29#define EC_BAT_SOC 0x16 /* uint8_t, percentage */ 30#define EC_BAT_SERIAL 0x17 /* uint8_t[6] */ 31#define EC_BAT_EEPROM 0x18 /* uint8_t adr as input, uint8_t output */ 32#define EC_BAT_ERRCODE 0x1f /* uint8_t, bitmask */ 33 34#define BAT_STAT_PRESENT 0x01 35#define BAT_STAT_FULL 0x02 36#define BAT_STAT_LOW 0x04 37#define BAT_STAT_DESTROY 0x08 38#define BAT_STAT_AC 0x10 39#define BAT_STAT_CHARGING 0x20 40#define BAT_STAT_DISCHARGING 0x40 41#define BAT_STAT_TRICKLE 0x80 42 43#define BAT_ERR_INFOFAIL 0x02 44#define BAT_ERR_OVERVOLTAGE 0x04 45#define BAT_ERR_OVERTEMP 0x05 46#define BAT_ERR_GAUGESTOP 0x06 47#define BAT_ERR_OUT_OF_CONTROL 0x07 48#define BAT_ERR_ID_FAIL 0x09 49#define BAT_ERR_ACR_FAIL 0x10 50 51#define BAT_ADDR_MFR_TYPE 0x5F 52 53/********************************************************************* 54 * Power 55 *********************************************************************/ 56 57static int olpc_ac_get_prop(struct power_supply *psy, 58 enum power_supply_property psp, 59 union power_supply_propval *val) 60{ 61 int ret = 0; 62 uint8_t status; 63 64 switch (psp) { 65 case POWER_SUPPLY_PROP_ONLINE: 66 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1); 67 if (ret) 68 return ret; 69 70 val->intval = !!(status & BAT_STAT_AC); 71 break; 72 default: 73 ret = -EINVAL; 74 break; 75 } 76 return ret; 77} 78 79static enum power_supply_property olpc_ac_props[] = { 80 POWER_SUPPLY_PROP_ONLINE, 81}; 82 83static struct power_supply olpc_ac = { 84 .name = "olpc-ac", 85 .type = POWER_SUPPLY_TYPE_MAINS, 86 .properties = olpc_ac_props, 87 .num_properties = ARRAY_SIZE(olpc_ac_props), 88 .get_property = olpc_ac_get_prop, 89}; 90 91static char bat_serial[17]; /* Ick */ 92 93static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte) 94{ 95 if (olpc_platform_info.ecver > 0x44) { 96 if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE)) 97 val->intval = POWER_SUPPLY_STATUS_CHARGING; 98 else if (ec_byte & BAT_STAT_DISCHARGING) 99 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 100 else if (ec_byte & BAT_STAT_FULL) 101 val->intval = POWER_SUPPLY_STATUS_FULL; 102 else /* er,... */ 103 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 104 } else { 105 /* Older EC didn't report charge/discharge bits */ 106 if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */ 107 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 108 else if (ec_byte & BAT_STAT_FULL) 109 val->intval = POWER_SUPPLY_STATUS_FULL; 110 else /* Not _necessarily_ true but EC doesn't tell all yet */ 111 val->intval = POWER_SUPPLY_STATUS_CHARGING; 112 } 113 114 return 0; 115} 116 117static int olpc_bat_get_health(union power_supply_propval *val) 118{ 119 uint8_t ec_byte; 120 int ret; 121 122 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1); 123 if (ret) 124 return ret; 125 126 switch (ec_byte) { 127 case 0: 128 val->intval = POWER_SUPPLY_HEALTH_GOOD; 129 break; 130 131 case BAT_ERR_OVERTEMP: 132 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; 133 break; 134 135 case BAT_ERR_OVERVOLTAGE: 136 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE; 137 break; 138 139 case BAT_ERR_INFOFAIL: 140 case BAT_ERR_OUT_OF_CONTROL: 141 case BAT_ERR_ID_FAIL: 142 case BAT_ERR_ACR_FAIL: 143 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE; 144 break; 145 146 default: 147 /* Eep. We don't know this failure code */ 148 ret = -EIO; 149 } 150 151 return ret; 152} 153 154static int olpc_bat_get_mfr(union power_supply_propval *val) 155{ 156 uint8_t ec_byte; 157 int ret; 158 159 ec_byte = BAT_ADDR_MFR_TYPE; 160 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1); 161 if (ret) 162 return ret; 163 164 switch (ec_byte >> 4) { 165 case 1: 166 val->strval = "Gold Peak"; 167 break; 168 case 2: 169 val->strval = "BYD"; 170 break; 171 default: 172 val->strval = "Unknown"; 173 break; 174 } 175 176 return ret; 177} 178 179static int olpc_bat_get_tech(union power_supply_propval *val) 180{ 181 uint8_t ec_byte; 182 int ret; 183 184 ec_byte = BAT_ADDR_MFR_TYPE; 185 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1); 186 if (ret) 187 return ret; 188 189 switch (ec_byte & 0xf) { 190 case 1: 191 val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH; 192 break; 193 case 2: 194 val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe; 195 break; 196 default: 197 val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN; 198 break; 199 } 200 201 return ret; 202} 203 204static int olpc_bat_get_charge_full_design(union power_supply_propval *val) 205{ 206 uint8_t ec_byte; 207 union power_supply_propval tech; 208 int ret, mfr; 209 210 ret = olpc_bat_get_tech(&tech); 211 if (ret) 212 return ret; 213 214 ec_byte = BAT_ADDR_MFR_TYPE; 215 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1); 216 if (ret) 217 return ret; 218 219 mfr = ec_byte >> 4; 220 221 switch (tech.intval) { 222 case POWER_SUPPLY_TECHNOLOGY_NiMH: 223 switch (mfr) { 224 case 1: /* Gold Peak */ 225 val->intval = 3000000*.8; 226 break; 227 default: 228 return -EIO; 229 } 230 break; 231 232 case POWER_SUPPLY_TECHNOLOGY_LiFe: 233 switch (mfr) { 234 case 1: /* Gold Peak */ 235 val->intval = 2800000; 236 break; 237 case 2: /* BYD */ 238 val->intval = 3100000; 239 break; 240 default: 241 return -EIO; 242 } 243 break; 244 245 default: 246 return -EIO; 247 } 248 249 return ret; 250} 251 252static int olpc_bat_get_charge_now(union power_supply_propval *val) 253{ 254 uint8_t soc; 255 union power_supply_propval full; 256 int ret; 257 258 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &soc, 1); 259 if (ret) 260 return ret; 261 262 ret = olpc_bat_get_charge_full_design(&full); 263 if (ret) 264 return ret; 265 266 val->intval = soc * (full.intval / 100); 267 return 0; 268} 269 270/********************************************************************* 271 * Battery properties 272 *********************************************************************/ 273static int olpc_bat_get_property(struct power_supply *psy, 274 enum power_supply_property psp, 275 union power_supply_propval *val) 276{ 277 int ret = 0; 278 __be16 ec_word; 279 uint8_t ec_byte; 280 __be64 ser_buf; 281 282 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1); 283 if (ret) 284 return ret; 285 286 /* Theoretically there's a race here -- the battery could be 287 removed immediately after we check whether it's present, and 288 then we query for some other property of the now-absent battery. 289 It doesn't matter though -- the EC will return the last-known 290 information, and it's as if we just ran that _little_ bit faster 291 and managed to read it out before the battery went away. */ 292 if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) && 293 psp != POWER_SUPPLY_PROP_PRESENT) 294 return -ENODEV; 295 296 switch (psp) { 297 case POWER_SUPPLY_PROP_STATUS: 298 ret = olpc_bat_get_status(val, ec_byte); 299 if (ret) 300 return ret; 301 break; 302 case POWER_SUPPLY_PROP_CHARGE_TYPE: 303 if (ec_byte & BAT_STAT_TRICKLE) 304 val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE; 305 else if (ec_byte & BAT_STAT_CHARGING) 306 val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST; 307 else 308 val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE; 309 break; 310 case POWER_SUPPLY_PROP_PRESENT: 311 val->intval = !!(ec_byte & (BAT_STAT_PRESENT | 312 BAT_STAT_TRICKLE)); 313 break; 314 315 case POWER_SUPPLY_PROP_HEALTH: 316 if (ec_byte & BAT_STAT_DESTROY) 317 val->intval = POWER_SUPPLY_HEALTH_DEAD; 318 else { 319 ret = olpc_bat_get_health(val); 320 if (ret) 321 return ret; 322 } 323 break; 324 325 case POWER_SUPPLY_PROP_MANUFACTURER: 326 ret = olpc_bat_get_mfr(val); 327 if (ret) 328 return ret; 329 break; 330 case POWER_SUPPLY_PROP_TECHNOLOGY: 331 ret = olpc_bat_get_tech(val); 332 if (ret) 333 return ret; 334 break; 335 case POWER_SUPPLY_PROP_VOLTAGE_AVG: 336 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2); 337 if (ret) 338 return ret; 339 340 val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32; 341 break; 342 case POWER_SUPPLY_PROP_CURRENT_AVG: 343 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2); 344 if (ret) 345 return ret; 346 347 val->intval = (s16)be16_to_cpu(ec_word) * 15625L / 120; 348 break; 349 case POWER_SUPPLY_PROP_CAPACITY: 350 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1); 351 if (ret) 352 return ret; 353 val->intval = ec_byte; 354 break; 355 case POWER_SUPPLY_PROP_CAPACITY_LEVEL: 356 if (ec_byte & BAT_STAT_FULL) 357 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL; 358 else if (ec_byte & BAT_STAT_LOW) 359 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW; 360 else 361 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL; 362 break; 363 case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: 364 ret = olpc_bat_get_charge_full_design(val); 365 if (ret) 366 return ret; 367 break; 368 case POWER_SUPPLY_PROP_CHARGE_NOW: 369 ret = olpc_bat_get_charge_now(val); 370 if (ret) 371 return ret; 372 break; 373 case POWER_SUPPLY_PROP_TEMP: 374 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2); 375 if (ret) 376 return ret; 377 378 val->intval = (s16)be16_to_cpu(ec_word) * 100 / 256; 379 break; 380 case POWER_SUPPLY_PROP_TEMP_AMBIENT: 381 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2); 382 if (ret) 383 return ret; 384 385 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256; 386 break; 387 case POWER_SUPPLY_PROP_CHARGE_COUNTER: 388 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2); 389 if (ret) 390 return ret; 391 392 val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15; 393 break; 394 case POWER_SUPPLY_PROP_SERIAL_NUMBER: 395 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8); 396 if (ret) 397 return ret; 398 399 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf)); 400 val->strval = bat_serial; 401 break; 402 default: 403 ret = -EINVAL; 404 break; 405 } 406 407 return ret; 408} 409 410static enum power_supply_property olpc_xo1_bat_props[] = { 411 POWER_SUPPLY_PROP_STATUS, 412 POWER_SUPPLY_PROP_CHARGE_TYPE, 413 POWER_SUPPLY_PROP_PRESENT, 414 POWER_SUPPLY_PROP_HEALTH, 415 POWER_SUPPLY_PROP_TECHNOLOGY, 416 POWER_SUPPLY_PROP_VOLTAGE_AVG, 417 POWER_SUPPLY_PROP_CURRENT_AVG, 418 POWER_SUPPLY_PROP_CAPACITY, 419 POWER_SUPPLY_PROP_CAPACITY_LEVEL, 420 POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, 421 POWER_SUPPLY_PROP_CHARGE_NOW, 422 POWER_SUPPLY_PROP_TEMP, 423 POWER_SUPPLY_PROP_TEMP_AMBIENT, 424 POWER_SUPPLY_PROP_MANUFACTURER, 425 POWER_SUPPLY_PROP_SERIAL_NUMBER, 426 POWER_SUPPLY_PROP_CHARGE_COUNTER, 427}; 428 429/* XO-1.5 does not have ambient temperature property */ 430static enum power_supply_property olpc_xo15_bat_props[] = { 431 POWER_SUPPLY_PROP_STATUS, 432 POWER_SUPPLY_PROP_CHARGE_TYPE, 433 POWER_SUPPLY_PROP_PRESENT, 434 POWER_SUPPLY_PROP_HEALTH, 435 POWER_SUPPLY_PROP_TECHNOLOGY, 436 POWER_SUPPLY_PROP_VOLTAGE_AVG, 437 POWER_SUPPLY_PROP_CURRENT_AVG, 438 POWER_SUPPLY_PROP_CAPACITY, 439 POWER_SUPPLY_PROP_CAPACITY_LEVEL, 440 POWER_SUPPLY_PROP_TEMP, 441 POWER_SUPPLY_PROP_MANUFACTURER, 442 POWER_SUPPLY_PROP_SERIAL_NUMBER, 443 POWER_SUPPLY_PROP_CHARGE_COUNTER, 444}; 445 446/* EEPROM reading goes completely around the power_supply API, sadly */ 447 448#define EEPROM_START 0x20 449#define EEPROM_END 0x80 450#define EEPROM_SIZE (EEPROM_END - EEPROM_START) 451 452static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj, 453 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 454{ 455 uint8_t ec_byte; 456 int ret; 457 int i; 458 459 if (off >= EEPROM_SIZE) 460 return 0; 461 if (off + count > EEPROM_SIZE) 462 count = EEPROM_SIZE - off; 463 464 for (i = 0; i < count; i++) { 465 ec_byte = EEPROM_START + off + i; 466 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1); 467 if (ret) { 468 pr_err("olpc-battery: " 469 "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n", 470 ec_byte, ret); 471 return -EIO; 472 } 473 } 474 475 return count; 476} 477 478static struct bin_attribute olpc_bat_eeprom = { 479 .attr = { 480 .name = "eeprom", 481 .mode = S_IRUGO, 482 }, 483 .size = 0, 484 .read = olpc_bat_eeprom_read, 485}; 486 487/* Allow userspace to see the specific error value pulled from the EC */ 488 489static ssize_t olpc_bat_error_read(struct device *dev, 490 struct device_attribute *attr, char *buf) 491{ 492 uint8_t ec_byte; 493 ssize_t ret; 494 495 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1); 496 if (ret < 0) 497 return ret; 498 499 return sprintf(buf, "%d\n", ec_byte); 500} 501 502static struct device_attribute olpc_bat_error = { 503 .attr = { 504 .name = "error", 505 .mode = S_IRUGO, 506 }, 507 .show = olpc_bat_error_read, 508}; 509 510/********************************************************************* 511 * Initialisation 512 *********************************************************************/ 513 514static struct platform_device *bat_pdev; 515 516static struct power_supply olpc_bat = { 517 .get_property = olpc_bat_get_property, 518 .use_for_apm = 1, 519}; 520 521void olpc_battery_trigger_uevent(unsigned long cause) 522{ 523 if (cause & EC_SCI_SRC_ACPWR) 524 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE); 525 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY)) 526 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE); 527} 528 529static int __init olpc_bat_init(void) 530{ 531 int ret = 0; 532 uint8_t status; 533 534 if (!olpc_platform_info.ecver) 535 return -ENXIO; 536 537 /* 538 * We've seen a number of EC protocol changes; this driver requires 539 * the latest EC protocol, supported by 0x44 and above. 540 */ 541 if (olpc_platform_info.ecver < 0x44) { 542 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for " 543 "battery driver.\n", olpc_platform_info.ecver); 544 return -ENXIO; 545 } 546 547 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1); 548 if (ret) 549 return ret; 550 551 /* Ignore the status. It doesn't actually matter */ 552 553 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0); 554 if (IS_ERR(bat_pdev)) 555 return PTR_ERR(bat_pdev); 556 557 ret = power_supply_register(&bat_pdev->dev, &olpc_ac); 558 if (ret) 559 goto ac_failed; 560 561 olpc_bat.name = bat_pdev->name; 562 if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */ 563 olpc_bat.properties = olpc_xo15_bat_props; 564 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props); 565 } else { /* XO-1 */ 566 olpc_bat.properties = olpc_xo1_bat_props; 567 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props); 568 } 569 570 ret = power_supply_register(&bat_pdev->dev, &olpc_bat); 571 if (ret) 572 goto battery_failed; 573 574 ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 575 if (ret) 576 goto eeprom_failed; 577 578 ret = device_create_file(olpc_bat.dev, &olpc_bat_error); 579 if (ret) 580 goto error_failed; 581 582 goto success; 583 584error_failed: 585 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 586eeprom_failed: 587 power_supply_unregister(&olpc_bat); 588battery_failed: 589 power_supply_unregister(&olpc_ac); 590ac_failed: 591 platform_device_unregister(bat_pdev); 592success: 593 return ret; 594} 595 596static void __exit olpc_bat_exit(void) 597{ 598 device_remove_file(olpc_bat.dev, &olpc_bat_error); 599 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 600 power_supply_unregister(&olpc_bat); 601 power_supply_unregister(&olpc_ac); 602 platform_device_unregister(bat_pdev); 603} 604 605module_init(olpc_bat_init); 606module_exit(olpc_bat_exit); 607 608MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 609MODULE_LICENSE("GPL"); 610MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine"); 611