drivers/power/olpc_battery.c

   1 /*
   2  * Battery driver for One Laptop Per Child board.
   3  *
   4  *      Copyright © 2006  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 /*********************************************************************
 205  *              Battery properties
 206  *********************************************************************/
 207 static 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
 334 static enum power_supply_property olpc_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 /* EEPROM reading goes completely around the power_supply API, sadly */
 352
 353 #define EEPROM_START    0x20
 354 #define EEPROM_END      0x80
 355 #define EEPROM_SIZE     (EEPROM_END - EEPROM_START)
 356
 357 static ssize_t olpc_bat_eeprom_read(struct kobject *kobj,
 358                 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 359 {
 360         uint8_t ec_byte;
 361         int ret;
 362         int i;
 363
 364         if (off >= EEPROM_SIZE)
 365                 return 0;
 366         if (off + count > EEPROM_SIZE)
 367                 count = EEPROM_SIZE - off;
 368
 369         for (i = 0; i < count; i++) {
 370                 ec_byte = EEPROM_START + off + i;
 371                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
 372                 if (ret) {
 373                         pr_err("olpc-battery: "
 374                                "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
 375                                ec_byte, ret);
 376                         return -EIO;
 377                 }
 378         }
 379
 380         return count;
 381 }
 382
 383 static struct bin_attribute olpc_bat_eeprom = {
 384         .attr = {
 385                 .name = "eeprom",
 386                 .mode = S_IRUGO,
 387                 .owner = THIS_MODULE,
 388         },
 389         .size = 0,
 390         .read = olpc_bat_eeprom_read,
 391 };
 392
 393 /* Allow userspace to see the specific error value pulled from the EC */
 394
 395 static ssize_t olpc_bat_error_read(struct device *dev,
 396                 struct device_attribute *attr, char *buf)
 397 {
 398         uint8_t ec_byte;
 399         ssize_t ret;
 400
 401         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 402         if (ret < 0)
 403                 return ret;
 404
 405         return sprintf(buf, "%d\n", ec_byte);
 406 }
 407
 408 static struct device_attribute olpc_bat_error = {
 409         .attr = {
 410                 .name = "error",
 411                 .mode = S_IRUGO,
 412         },
 413         .show = olpc_bat_error_read,
 414 };
 415
 416 /*********************************************************************
 417  *              Initialisation
 418  *********************************************************************/
 419
 420 static struct platform_device *bat_pdev;
 421
 422 static struct power_supply olpc_bat = {
 423         .properties = olpc_bat_props,
 424         .num_properties = ARRAY_SIZE(olpc_bat_props),
 425         .get_property = olpc_bat_get_property,
 426         .use_for_apm = 1,
 427 };
 428
 429 void olpc_battery_trigger_uevent(unsigned long cause)
 430 {
 431         if (cause & EC_SCI_SRC_ACPWR)
 432                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 433         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 434                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 435 }
 436
 437 static int __init olpc_bat_init(void)
 438 {
 439         int ret = 0;
 440         uint8_t status;
 441
 442         if (!olpc_platform_info.ecver)
 443                 return -ENXIO;
 444
 445         /*
 446          * We've seen a number of EC protocol changes; this driver requires
 447          * the latest EC protocol, supported by 0x44 and above.
 448          */
 449         if (olpc_platform_info.ecver < 0x44) {
 450                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
 451                         "battery driver.\n", olpc_platform_info.ecver);
 452                 return -ENXIO;
 453         }
 454
 455         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 456         if (ret)
 457                 return ret;
 458
 459         /* Ignore the status. It doesn't actually matter */
 460
 461         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 462         if (IS_ERR(bat_pdev))
 463                 return PTR_ERR(bat_pdev);
 464
 465         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 466         if (ret)
 467                 goto ac_failed;
 468
 469         olpc_bat.name = bat_pdev->name;
 470
 471         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 472         if (ret)
 473                 goto battery_failed;
 474
 475         ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 476         if (ret)
 477                 goto eeprom_failed;
 478
 479         ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
 480         if (ret)
 481                 goto error_failed;
 482
 483         goto success;
 484
 485 error_failed:
 486         device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 487 eeprom_failed:
 488         power_supply_unregister(&olpc_bat);
 489 battery_failed:
 490         power_supply_unregister(&olpc_ac);
 491 ac_failed:
 492         platform_device_unregister(bat_pdev);
 493 success:
 494         return ret;
 495 }
 496
 497 static void __exit olpc_bat_exit(void)
 498 {
 499         device_remove_file(olpc_bat.dev, &olpc_bat_error);
 500         device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 501         power_supply_unregister(&olpc_bat);
 502         power_supply_unregister(&olpc_ac);
 503         platform_device_unregister(bat_pdev);
 504 }
 505
 506 module_init(olpc_bat_init);
 507 module_exit(olpc_bat_exit);
 508
 509 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 510 MODULE_LICENSE("GPL");
 511 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");