drivers/power/olpc_battery.c

   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
  57 static 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
  79 static enum power_supply_property olpc_ac_props[] = {
  80         POWER_SUPPLY_PROP_ONLINE,
  81 };
  82
  83 static 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
  91 static char bat_serial[17]; /* Ick */
  92
  93 static 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
 117 static 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
 154 static 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
 179 static 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 static 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
 252 /*********************************************************************
 253  *              Battery properties
 254  *********************************************************************/
 255 static int olpc_bat_get_property(struct power_supply *psy,
 256                                  enum power_supply_property psp,
 257                                  union power_supply_propval *val)
 258 {
 259         int ret = 0;
 260         __be16 ec_word;
 261         uint8_t ec_byte;
 262         __be64 ser_buf;
 263
 264         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
 265         if (ret)
 266                 return ret;
 267
 268         /* Theoretically there's a race here -- the battery could be
 269            removed immediately after we check whether it's present, and
 270            then we query for some other property of the now-absent battery.
 271            It doesn't matter though -- the EC will return the last-known
 272            information, and it's as if we just ran that _little_ bit faster
 273            and managed to read it out before the battery went away. */
 274         if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) &&
 275                         psp != POWER_SUPPLY_PROP_PRESENT)
 276                 return -ENODEV;
 277
 278         switch (psp) {
 279         case POWER_SUPPLY_PROP_STATUS:
 280                 ret = olpc_bat_get_status(val, ec_byte);
 281                 if (ret)
 282                         return ret;
 283                 break;
 284         case POWER_SUPPLY_PROP_CHARGE_TYPE:
 285                 if (ec_byte & BAT_STAT_TRICKLE)
 286                         val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
 287                 else if (ec_byte & BAT_STAT_CHARGING)
 288                         val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
 289                 else
 290                         val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
 291                 break;
 292         case POWER_SUPPLY_PROP_PRESENT:
 293                 val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
 294                                             BAT_STAT_TRICKLE));
 295                 break;
 296
 297         case POWER_SUPPLY_PROP_HEALTH:
 298                 if (ec_byte & BAT_STAT_DESTROY)
 299                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 300                 else {
 301                         ret = olpc_bat_get_health(val);
 302                         if (ret)
 303                                 return ret;
 304                 }
 305                 break;
 306
 307         case POWER_SUPPLY_PROP_MANUFACTURER:
 308                 ret = olpc_bat_get_mfr(val);
 309                 if (ret)
 310                         return ret;
 311                 break;
 312         case POWER_SUPPLY_PROP_TECHNOLOGY:
 313                 ret = olpc_bat_get_tech(val);
 314                 if (ret)
 315                         return ret;
 316                 break;
 317         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 318                 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 319                 if (ret)
 320                         return ret;
 321
 322                 val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32;
 323                 break;
 324         case POWER_SUPPLY_PROP_CURRENT_AVG:
 325                 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 326                 if (ret)
 327                         return ret;
 328
 329                 val->intval = (s16)be16_to_cpu(ec_word) * 15625L / 120;
 330                 break;
 331         case POWER_SUPPLY_PROP_CAPACITY:
 332                 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
 333                 if (ret)
 334                         return ret;
 335                 val->intval = ec_byte;
 336                 break;
 337         case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
 338                 if (ec_byte & BAT_STAT_FULL)
 339                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 340                 else if (ec_byte & BAT_STAT_LOW)
 341                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 342                 else
 343                         val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 344                 break;
 345         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 346                 ret = olpc_bat_get_charge_full_design(val);
 347                 if (ret)
 348                         return ret;
 349                 break;
 350         case POWER_SUPPLY_PROP_TEMP:
 351                 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 352                 if (ret)
 353                         return ret;
 354
 355                 val->intval = (s16)be16_to_cpu(ec_word) * 100 / 256;
 356                 break;
 357         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 358                 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
 359                 if (ret)
 360                         return ret;
 361
 362                 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
 363                 break;
 364         case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 365                 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
 366                 if (ret)
 367                         return ret;
 368
 369                 val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15;
 370                 break;
 371         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 372                 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
 373                 if (ret)
 374                         return ret;
 375
 376                 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
 377                 val->strval = bat_serial;
 378                 break;
 379         default:
 380                 ret = -EINVAL;
 381                 break;
 382         }
 383
 384         return ret;
 385 }
 386
 387 static enum power_supply_property olpc_xo1_bat_props[] = {
 388         POWER_SUPPLY_PROP_STATUS,
 389         POWER_SUPPLY_PROP_CHARGE_TYPE,
 390         POWER_SUPPLY_PROP_PRESENT,
 391         POWER_SUPPLY_PROP_HEALTH,
 392         POWER_SUPPLY_PROP_TECHNOLOGY,
 393         POWER_SUPPLY_PROP_VOLTAGE_AVG,
 394         POWER_SUPPLY_PROP_CURRENT_AVG,
 395         POWER_SUPPLY_PROP_CAPACITY,
 396         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 397         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 398         POWER_SUPPLY_PROP_TEMP,
 399         POWER_SUPPLY_PROP_TEMP_AMBIENT,
 400         POWER_SUPPLY_PROP_MANUFACTURER,
 401         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 402         POWER_SUPPLY_PROP_CHARGE_COUNTER,
 403 };
 404
 405 /* XO-1.5 does not have ambient temperature property */
 406 static enum power_supply_property olpc_xo15_bat_props[] = {
 407         POWER_SUPPLY_PROP_STATUS,
 408         POWER_SUPPLY_PROP_CHARGE_TYPE,
 409         POWER_SUPPLY_PROP_PRESENT,
 410         POWER_SUPPLY_PROP_HEALTH,
 411         POWER_SUPPLY_PROP_TECHNOLOGY,
 412         POWER_SUPPLY_PROP_VOLTAGE_AVG,
 413         POWER_SUPPLY_PROP_CURRENT_AVG,
 414         POWER_SUPPLY_PROP_CAPACITY,
 415         POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 416         POWER_SUPPLY_PROP_TEMP,
 417         POWER_SUPPLY_PROP_MANUFACTURER,
 418         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 419         POWER_SUPPLY_PROP_CHARGE_COUNTER,
 420 };
 421
 422 /* EEPROM reading goes completely around the power_supply API, sadly */
 423
 424 #define EEPROM_START    0x20
 425 #define EEPROM_END      0x80
 426 #define EEPROM_SIZE     (EEPROM_END - EEPROM_START)
 427
 428 static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj,
 429                 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 430 {
 431         uint8_t ec_byte;
 432         int ret;
 433         int i;
 434
 435         if (off >= EEPROM_SIZE)
 436                 return 0;
 437         if (off + count > EEPROM_SIZE)
 438                 count = EEPROM_SIZE - off;
 439
 440         for (i = 0; i < count; i++) {
 441                 ec_byte = EEPROM_START + off + i;
 442                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
 443                 if (ret) {
 444                         pr_err("olpc-battery: "
 445                                "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
 446                                ec_byte, ret);
 447                         return -EIO;
 448                 }
 449         }
 450
 451         return count;
 452 }
 453
 454 static struct bin_attribute olpc_bat_eeprom = {
 455         .attr = {
 456                 .name = "eeprom",
 457                 .mode = S_IRUGO,
 458         },
 459         .size = 0,
 460         .read = olpc_bat_eeprom_read,
 461 };
 462
 463 /* Allow userspace to see the specific error value pulled from the EC */
 464
 465 static ssize_t olpc_bat_error_read(struct device *dev,
 466                 struct device_attribute *attr, char *buf)
 467 {
 468         uint8_t ec_byte;
 469         ssize_t ret;
 470
 471         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 472         if (ret < 0)
 473                 return ret;
 474
 475         return sprintf(buf, "%d\n", ec_byte);
 476 }
 477
 478 static struct device_attribute olpc_bat_error = {
 479         .attr = {
 480                 .name = "error",
 481                 .mode = S_IRUGO,
 482         },
 483         .show = olpc_bat_error_read,
 484 };
 485
 486 /*********************************************************************
 487  *              Initialisation
 488  *********************************************************************/
 489
 490 static struct platform_device *bat_pdev;
 491
 492 static struct power_supply olpc_bat = {
 493         .get_property = olpc_bat_get_property,
 494         .use_for_apm = 1,
 495 };
 496
 497 void olpc_battery_trigger_uevent(unsigned long cause)
 498 {
 499         if (cause & EC_SCI_SRC_ACPWR)
 500                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 501         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 502                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 503 }
 504
 505 static int __init olpc_bat_init(void)
 506 {
 507         int ret = 0;
 508         uint8_t status;
 509
 510         if (!olpc_platform_info.ecver)
 511                 return -ENXIO;
 512
 513         /*
 514          * We've seen a number of EC protocol changes; this driver requires
 515          * the latest EC protocol, supported by 0x44 and above.
 516          */
 517         if (olpc_platform_info.ecver < 0x44) {
 518                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
 519                         "battery driver.\n", olpc_platform_info.ecver);
 520                 return -ENXIO;
 521         }
 522
 523         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 524         if (ret)
 525                 return ret;
 526
 527         /* Ignore the status. It doesn't actually matter */
 528
 529         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 530         if (IS_ERR(bat_pdev))
 531                 return PTR_ERR(bat_pdev);
 532
 533         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 534         if (ret)
 535                 goto ac_failed;
 536
 537         olpc_bat.name = bat_pdev->name;
 538         if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */
 539                 olpc_bat.properties = olpc_xo15_bat_props;
 540                 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props);
 541         } else { /* XO-1 */
 542                 olpc_bat.properties = olpc_xo1_bat_props;
 543                 olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props);
 544         }
 545
 546         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 547         if (ret)
 548                 goto battery_failed;
 549
 550         ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 551         if (ret)
 552                 goto eeprom_failed;
 553
 554         ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
 555         if (ret)
 556                 goto error_failed;
 557
 558         goto success;
 559
 560 error_failed:
 561         device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 562 eeprom_failed:
 563         power_supply_unregister(&olpc_bat);
 564 battery_failed:
 565         power_supply_unregister(&olpc_ac);
 566 ac_failed:
 567         platform_device_unregister(bat_pdev);
 568 success:
 569         return ret;
 570 }
 571
 572 static void __exit olpc_bat_exit(void)
 573 {
 574         device_remove_file(olpc_bat.dev, &olpc_bat_error);
 575         device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 576         power_supply_unregister(&olpc_bat);
 577         power_supply_unregister(&olpc_ac);
 578         platform_device_unregister(bat_pdev);
 579 }
 580
 581 module_init(olpc_bat_init);
 582 module_exit(olpc_bat_exit);
 583
 584 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 585 MODULE_LICENSE("GPL");
 586 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");