olpc_battery.c revision c566d299f91bdb622046126dbcb040f9e52572ba
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} 203 204/********************************************************************* 205 * Battery properties 206 *********************************************************************/ 207static int olpc_bat_get_property(struct power_supply *psy, 208 enum power_supply_property psp, 209 union power_supply_propval *val) 210{ 211 int ret = 0; 212 __be16 ec_word; 213 uint8_t ec_byte; 214 __be64 ser_buf; 215 216 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1); 217 if (ret) 218 return ret; 219 220 /* Theoretically there's a race here -- the battery could be 221 removed immediately after we check whether it's present, and 222 then we query for some other property of the now-absent battery. 223 It doesn't matter though -- the EC will return the last-known 224 information, and it's as if we just ran that _little_ bit faster 225 and managed to read it out before the battery went away. */ 226 if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) && 227 psp != POWER_SUPPLY_PROP_PRESENT) 228 return -ENODEV; 229 230 switch (psp) { 231 case POWER_SUPPLY_PROP_STATUS: 232 ret = olpc_bat_get_status(val, ec_byte); 233 if (ret) 234 return ret; 235 break; 236 case POWER_SUPPLY_PROP_CHARGE_TYPE: 237 if (ec_byte & BAT_STAT_TRICKLE) 238 val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE; 239 else if (ec_byte & BAT_STAT_CHARGING) 240 val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST; 241 else 242 val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE; 243 break; 244 case POWER_SUPPLY_PROP_PRESENT: 245 val->intval = !!(ec_byte & (BAT_STAT_PRESENT | 246 BAT_STAT_TRICKLE)); 247 break; 248 249 case POWER_SUPPLY_PROP_HEALTH: 250 if (ec_byte & BAT_STAT_DESTROY) 251 val->intval = POWER_SUPPLY_HEALTH_DEAD; 252 else { 253 ret = olpc_bat_get_health(val); 254 if (ret) 255 return ret; 256 } 257 break; 258 259 case POWER_SUPPLY_PROP_MANUFACTURER: 260 ret = olpc_bat_get_mfr(val); 261 if (ret) 262 return ret; 263 break; 264 case POWER_SUPPLY_PROP_TECHNOLOGY: 265 ret = olpc_bat_get_tech(val); 266 if (ret) 267 return ret; 268 break; 269 case POWER_SUPPLY_PROP_VOLTAGE_AVG: 270 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2); 271 if (ret) 272 return ret; 273 274 val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32; 275 break; 276 case POWER_SUPPLY_PROP_CURRENT_AVG: 277 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2); 278 if (ret) 279 return ret; 280 281 val->intval = (s16)be16_to_cpu(ec_word) * 15625L / 120; 282 break; 283 case POWER_SUPPLY_PROP_CAPACITY: 284 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1); 285 if (ret) 286 return ret; 287 val->intval = ec_byte; 288 break; 289 case POWER_SUPPLY_PROP_CAPACITY_LEVEL: 290 if (ec_byte & BAT_STAT_FULL) 291 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL; 292 else if (ec_byte & BAT_STAT_LOW) 293 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW; 294 else 295 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL; 296 break; 297 case POWER_SUPPLY_PROP_TEMP: 298 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2); 299 if (ret) 300 return ret; 301 302 val->intval = (s16)be16_to_cpu(ec_word) * 100 / 256; 303 break; 304 case POWER_SUPPLY_PROP_TEMP_AMBIENT: 305 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2); 306 if (ret) 307 return ret; 308 309 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256; 310 break; 311 case POWER_SUPPLY_PROP_CHARGE_COUNTER: 312 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2); 313 if (ret) 314 return ret; 315 316 val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15; 317 break; 318 case POWER_SUPPLY_PROP_SERIAL_NUMBER: 319 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8); 320 if (ret) 321 return ret; 322 323 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf)); 324 val->strval = bat_serial; 325 break; 326 default: 327 ret = -EINVAL; 328 break; 329 } 330 331 return ret; 332} 333 334static enum power_supply_property olpc_xo1_bat_props[] = { 335 POWER_SUPPLY_PROP_STATUS, 336 POWER_SUPPLY_PROP_CHARGE_TYPE, 337 POWER_SUPPLY_PROP_PRESENT, 338 POWER_SUPPLY_PROP_HEALTH, 339 POWER_SUPPLY_PROP_TECHNOLOGY, 340 POWER_SUPPLY_PROP_VOLTAGE_AVG, 341 POWER_SUPPLY_PROP_CURRENT_AVG, 342 POWER_SUPPLY_PROP_CAPACITY, 343 POWER_SUPPLY_PROP_CAPACITY_LEVEL, 344 POWER_SUPPLY_PROP_TEMP, 345 POWER_SUPPLY_PROP_TEMP_AMBIENT, 346 POWER_SUPPLY_PROP_MANUFACTURER, 347 POWER_SUPPLY_PROP_SERIAL_NUMBER, 348 POWER_SUPPLY_PROP_CHARGE_COUNTER, 349}; 350 351/* XO-1.5 does not have ambient temperature property */ 352static enum power_supply_property olpc_xo15_bat_props[] = { 353 POWER_SUPPLY_PROP_STATUS, 354 POWER_SUPPLY_PROP_CHARGE_TYPE, 355 POWER_SUPPLY_PROP_PRESENT, 356 POWER_SUPPLY_PROP_HEALTH, 357 POWER_SUPPLY_PROP_TECHNOLOGY, 358 POWER_SUPPLY_PROP_VOLTAGE_AVG, 359 POWER_SUPPLY_PROP_CURRENT_AVG, 360 POWER_SUPPLY_PROP_CAPACITY, 361 POWER_SUPPLY_PROP_CAPACITY_LEVEL, 362 POWER_SUPPLY_PROP_TEMP, 363 POWER_SUPPLY_PROP_MANUFACTURER, 364 POWER_SUPPLY_PROP_SERIAL_NUMBER, 365 POWER_SUPPLY_PROP_CHARGE_COUNTER, 366}; 367 368/* EEPROM reading goes completely around the power_supply API, sadly */ 369 370#define EEPROM_START 0x20 371#define EEPROM_END 0x80 372#define EEPROM_SIZE (EEPROM_END - EEPROM_START) 373 374static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj, 375 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 376{ 377 uint8_t ec_byte; 378 int ret; 379 int i; 380 381 if (off >= EEPROM_SIZE) 382 return 0; 383 if (off + count > EEPROM_SIZE) 384 count = EEPROM_SIZE - off; 385 386 for (i = 0; i < count; i++) { 387 ec_byte = EEPROM_START + off + i; 388 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1); 389 if (ret) { 390 pr_err("olpc-battery: " 391 "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n", 392 ec_byte, ret); 393 return -EIO; 394 } 395 } 396 397 return count; 398} 399 400static struct bin_attribute olpc_bat_eeprom = { 401 .attr = { 402 .name = "eeprom", 403 .mode = S_IRUGO, 404 }, 405 .size = 0, 406 .read = olpc_bat_eeprom_read, 407}; 408 409/* Allow userspace to see the specific error value pulled from the EC */ 410 411static ssize_t olpc_bat_error_read(struct device *dev, 412 struct device_attribute *attr, char *buf) 413{ 414 uint8_t ec_byte; 415 ssize_t ret; 416 417 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1); 418 if (ret < 0) 419 return ret; 420 421 return sprintf(buf, "%d\n", ec_byte); 422} 423 424static struct device_attribute olpc_bat_error = { 425 .attr = { 426 .name = "error", 427 .mode = S_IRUGO, 428 }, 429 .show = olpc_bat_error_read, 430}; 431 432/********************************************************************* 433 * Initialisation 434 *********************************************************************/ 435 436static struct platform_device *bat_pdev; 437 438static struct power_supply olpc_bat = { 439 .get_property = olpc_bat_get_property, 440 .use_for_apm = 1, 441}; 442 443void olpc_battery_trigger_uevent(unsigned long cause) 444{ 445 if (cause & EC_SCI_SRC_ACPWR) 446 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE); 447 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY)) 448 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE); 449} 450 451static int __init olpc_bat_init(void) 452{ 453 int ret = 0; 454 uint8_t status; 455 456 if (!olpc_platform_info.ecver) 457 return -ENXIO; 458 459 /* 460 * We've seen a number of EC protocol changes; this driver requires 461 * the latest EC protocol, supported by 0x44 and above. 462 */ 463 if (olpc_platform_info.ecver < 0x44) { 464 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for " 465 "battery driver.\n", olpc_platform_info.ecver); 466 return -ENXIO; 467 } 468 469 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1); 470 if (ret) 471 return ret; 472 473 /* Ignore the status. It doesn't actually matter */ 474 475 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0); 476 if (IS_ERR(bat_pdev)) 477 return PTR_ERR(bat_pdev); 478 479 ret = power_supply_register(&bat_pdev->dev, &olpc_ac); 480 if (ret) 481 goto ac_failed; 482 483 olpc_bat.name = bat_pdev->name; 484 if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */ 485 olpc_bat.properties = olpc_xo15_bat_props; 486 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props); 487 } else { /* XO-1 */ 488 olpc_bat.properties = olpc_xo1_bat_props; 489 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props); 490 } 491 492 ret = power_supply_register(&bat_pdev->dev, &olpc_bat); 493 if (ret) 494 goto battery_failed; 495 496 ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 497 if (ret) 498 goto eeprom_failed; 499 500 ret = device_create_file(olpc_bat.dev, &olpc_bat_error); 501 if (ret) 502 goto error_failed; 503 504 goto success; 505 506error_failed: 507 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 508eeprom_failed: 509 power_supply_unregister(&olpc_bat); 510battery_failed: 511 power_supply_unregister(&olpc_ac); 512ac_failed: 513 platform_device_unregister(bat_pdev); 514success: 515 return ret; 516} 517 518static void __exit olpc_bat_exit(void) 519{ 520 device_remove_file(olpc_bat.dev, &olpc_bat_error); 521 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 522 power_supply_unregister(&olpc_bat); 523 power_supply_unregister(&olpc_ac); 524 platform_device_unregister(bat_pdev); 525} 526 527module_init(olpc_bat_init); 528module_exit(olpc_bat_exit); 529 530MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 531MODULE_LICENSE("GPL"); 532MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine"); 533