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/err.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/power_supply.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/sched.h>
  18 #include <asm/olpc.h>
  19
  20
  21 #define EC_BAT_VOLTAGE  0x10    /* uint16_t,    *9.76/32,    mV   */
  22 #define EC_BAT_CURRENT  0x11    /* int16_t,     *15.625/120, mA   */
  23 #define EC_BAT_ACR      0x12    /* int16_t,     *6250/15,    µAh  */
  24 #define EC_BAT_TEMP     0x13    /* uint16_t,    *100/256,   °C  */
  25 #define EC_AMB_TEMP     0x14    /* uint16_t,    *100/256,   °C  */
  26 #define EC_BAT_STATUS   0x15    /* uint8_t,     bitmask */
  27 #define EC_BAT_SOC      0x16    /* uint8_t,     percentage */
  28 #define EC_BAT_SERIAL   0x17    /* uint8_t[6] */
  29 #define EC_BAT_EEPROM   0x18    /* uint8_t adr as input, uint8_t output */
  30 #define EC_BAT_ERRCODE  0x1f    /* uint8_t,     bitmask */
  31
  32 #define BAT_STAT_PRESENT        0x01
  33 #define BAT_STAT_FULL           0x02
  34 #define BAT_STAT_LOW            0x04
  35 #define BAT_STAT_DESTROY        0x08
  36 #define BAT_STAT_AC             0x10
  37 #define BAT_STAT_CHARGING       0x20
  38 #define BAT_STAT_DISCHARGING    0x40
  39
  40 #define BAT_ERR_INFOFAIL        0x02
  41 #define BAT_ERR_OVERVOLTAGE     0x04
  42 #define BAT_ERR_OVERTEMP        0x05
  43 #define BAT_ERR_GAUGESTOP       0x06
  44 #define BAT_ERR_OUT_OF_CONTROL  0x07
  45 #define BAT_ERR_ID_FAIL         0x09
  46 #define BAT_ERR_ACR_FAIL        0x10
  47
  48 #define BAT_ADDR_MFR_TYPE       0x5F
  49
  50 /*********************************************************************
  51  *              Power
  52  *********************************************************************/
  53
  54 static int olpc_ac_get_prop(struct power_supply *psy,
  55                             enum power_supply_property psp,
  56                             union power_supply_propval *val)
  57 {
  58         int ret = 0;
  59         uint8_t status;
  60
  61         switch (psp) {
  62         case POWER_SUPPLY_PROP_ONLINE:
  63                 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
  64                 if (ret)
  65                         return ret;
  66
  67                 val->intval = !!(status & BAT_STAT_AC);
  68                 break;
  69         default:
  70                 ret = -EINVAL;
  71                 break;
  72         }
  73         return ret;
  74 }
  75
  76 static enum power_supply_property olpc_ac_props[] = {
  77         POWER_SUPPLY_PROP_ONLINE,
  78 };
  79
  80 static struct power_supply olpc_ac = {
  81         .name = "olpc-ac",
  82         .type = POWER_SUPPLY_TYPE_MAINS,
  83         .properties = olpc_ac_props,
  84         .num_properties = ARRAY_SIZE(olpc_ac_props),
  85         .get_property = olpc_ac_get_prop,
  86 };
  87
  88 static char bat_serial[17]; /* Ick */
  89
  90 static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
  91 {
  92         if (olpc_platform_info.ecver > 0x44) {
  93                 if (ec_byte & BAT_STAT_CHARGING)
  94                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
  95                 else if (ec_byte & BAT_STAT_DISCHARGING)
  96                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
  97                 else if (ec_byte & BAT_STAT_FULL)
  98                         val->intval = POWER_SUPPLY_STATUS_FULL;
  99                 else /* er,... */
 100                         val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 101         } else {
 102                 /* Older EC didn't report charge/discharge bits */
 103                 if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
 104                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 105                 else if (ec_byte & BAT_STAT_FULL)
 106                         val->intval = POWER_SUPPLY_STATUS_FULL;
 107                 else /* Not _necessarily_ true but EC doesn't tell all yet */
 108                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
 109         }
 110
 111         return 0;
 112 }
 113
 114 static int olpc_bat_get_health(union power_supply_propval *val)
 115 {
 116         uint8_t ec_byte;
 117         int ret;
 118
 119         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 120         if (ret)
 121                 return ret;
 122
 123         switch (ec_byte) {
 124         case 0:
 125                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
 126                 break;
 127
 128         case BAT_ERR_OVERTEMP:
 129                 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 130                 break;
 131
 132         case BAT_ERR_OVERVOLTAGE:
 133                 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 134                 break;
 135
 136         case BAT_ERR_INFOFAIL:
 137         case BAT_ERR_OUT_OF_CONTROL:
 138         case BAT_ERR_ID_FAIL:
 139         case BAT_ERR_ACR_FAIL:
 140                 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 141                 break;
 142
 143         default:
 144                 /* Eep. We don't know this failure code */
 145                 ret = -EIO;
 146         }
 147
 148         return ret;
 149 }
 150
 151 static int olpc_bat_get_mfr(union power_supply_propval *val)
 152 {
 153         uint8_t ec_byte;
 154         int ret;
 155
 156         ec_byte = BAT_ADDR_MFR_TYPE;
 157         ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 158         if (ret)
 159                 return ret;
 160
 161         switch (ec_byte >> 4) {
 162         case 1:
 163                 val->strval = "Gold Peak";
 164                 break;
 165         case 2:
 166                 val->strval = "BYD";
 167                 break;
 168         default:
 169                 val->strval = "Unknown";
 170                 break;
 171         }
 172
 173         return ret;
 174 }
 175
 176 static int olpc_bat_get_tech(union power_supply_propval *val)
 177 {
 178         uint8_t ec_byte;
 179         int ret;
 180
 181         ec_byte = BAT_ADDR_MFR_TYPE;
 182         ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 183         if (ret)
 184                 return ret;
 185
 186         switch (ec_byte & 0xf) {
 187         case 1:
 188                 val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
 189                 break;
 190         case 2:
 191                 val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
 192                 break;
 193         default:
 194                 val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 195                 break;
 196         }
 197
 198         return ret;
 199 }
 200
 201 /*********************************************************************
 202  *              Battery properties
 203  *********************************************************************/
 204 static int olpc_bat_get_property(struct power_supply *psy,
 205                                  enum power_supply_property psp,
 206                                  union power_supply_propval *val)
 207 {
 208         int ret = 0;
 209         __be16 ec_word;
 210         uint8_t ec_byte;
 211         __be64 ser_buf;
 212
 213         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
 214         if (ret)
 215                 return ret;
 216
 217         /* Theoretically there's a race here -- the battery could be
 218            removed immediately after we check whether it's present, and
 219            then we query for some other property of the now-absent battery.
 220            It doesn't matter though -- the EC will return the last-known
 221            information, and it's as if we just ran that _little_ bit faster
 222            and managed to read it out before the battery went away. */
 223         if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
 224                 return -ENODEV;
 225
 226         switch (psp) {
 227         case POWER_SUPPLY_PROP_STATUS:
 228                 ret = olpc_bat_get_status(val, ec_byte);
 229                 if (ret)
 230                         return ret;
 231                 break;
 232         case POWER_SUPPLY_PROP_PRESENT:
 233                 val->intval = !!(ec_byte & BAT_STAT_PRESENT);
 234                 break;
 235
 236         case POWER_SUPPLY_PROP_HEALTH:
 237                 if (ec_byte & BAT_STAT_DESTROY)
 238                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 239                 else {
 240                         ret = olpc_bat_get_health(val);
 241                         if (ret)
 242                                 return ret;
 243                 }
 244                 break;
 245
 246         case POWER_SUPPLY_PROP_MANUFACTURER:
 247                 ret = olpc_bat_get_mfr(val);
 248                 if (ret)
 249                         return ret;
 250                 break;
 251         case POWER_SUPPLY_PROP_TECHNOLOGY:
 252                 ret = olpc_bat_get_tech(val);
 253                 if (ret)
 254                         return ret;
 255                 break;
 256         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 257                 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 258                 if (ret)
 259                         return ret;
 260
 261                 val->intval = (int)be16_to_cpu(ec_word) * 9760L / 32;
 262                 break;
 263         case POWER_SUPPLY_PROP_CURRENT_AVG:
 264                 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 265                 if (ret)
 266                         return ret;
 267
 268                 val->intval = (int)be16_to_cpu(ec_word) * 15625L / 120;
 269                 break;
 270         case POWER_SUPPLY_PROP_CAPACITY:
 271                 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
 272                 if (ret)
 273                         return ret;
 274                 val->intval = ec_byte;
 275                 break;
 276         case POWER_SUPPLY_PROP_TEMP:
 277                 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 278                 if (ret)
 279                         return ret;
 280
 281                 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
 282                 break;
 283         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 284                 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
 285                 if (ret)
 286                         return ret;
 287
 288                 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
 289                 break;
 290         case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 291                 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
 292                 if (ret)
 293                         return ret;
 294
 295                 val->intval = (int)be16_to_cpu(ec_word) * 6250 / 15;
 296                 break;
 297         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 298                 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
 299                 if (ret)
 300                         return ret;
 301
 302                 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
 303                 val->strval = bat_serial;
 304                 break;
 305         default:
 306                 ret = -EINVAL;
 307                 break;
 308         }
 309
 310         return ret;
 311 }
 312
 313 static enum power_supply_property olpc_bat_props[] = {
 314         POWER_SUPPLY_PROP_STATUS,
 315         POWER_SUPPLY_PROP_PRESENT,
 316         POWER_SUPPLY_PROP_HEALTH,
 317         POWER_SUPPLY_PROP_TECHNOLOGY,
 318         POWER_SUPPLY_PROP_VOLTAGE_AVG,
 319         POWER_SUPPLY_PROP_CURRENT_AVG,
 320         POWER_SUPPLY_PROP_CAPACITY,
 321         POWER_SUPPLY_PROP_TEMP,
 322         POWER_SUPPLY_PROP_TEMP_AMBIENT,
 323         POWER_SUPPLY_PROP_MANUFACTURER,
 324         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 325         POWER_SUPPLY_PROP_CHARGE_COUNTER,
 326 };
 327
 328 /* EEPROM reading goes completely around the power_supply API, sadly */
 329
 330 #define EEPROM_START    0x20
 331 #define EEPROM_END      0x80
 332 #define EEPROM_SIZE     (EEPROM_END - EEPROM_START)
 333
 334 static ssize_t olpc_bat_eeprom_read(struct kobject *kobj,
 335                 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 336 {
 337         uint8_t ec_byte;
 338         int ret;
 339         int i;
 340
 341         if (off >= EEPROM_SIZE)
 342                 return 0;
 343         if (off + count > EEPROM_SIZE)
 344                 count = EEPROM_SIZE - off;
 345
 346         for (i = 0; i < count; i++) {
 347                 ec_byte = EEPROM_START + off + i;
 348                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
 349                 if (ret) {
 350                         pr_err("olpc-battery: "
 351                                "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
 352                                ec_byte, ret);
 353                         return -EIO;
 354                 }
 355         }
 356
 357         return count;
 358 }
 359
 360 static struct bin_attribute olpc_bat_eeprom = {
 361         .attr = {
 362                 .name = "eeprom",
 363                 .mode = S_IRUGO,
 364                 .owner = THIS_MODULE,
 365         },
 366         .size = 0,
 367         .read = olpc_bat_eeprom_read,
 368 };
 369
 370 /*********************************************************************
 371  *              Initialisation
 372  *********************************************************************/
 373
 374 static struct platform_device *bat_pdev;
 375
 376 static struct power_supply olpc_bat = {
 377         .properties = olpc_bat_props,
 378         .num_properties = ARRAY_SIZE(olpc_bat_props),
 379         .get_property = olpc_bat_get_property,
 380         .use_for_apm = 1,
 381 };
 382
 383 void olpc_battery_trigger_uevent(unsigned long cause)
 384 {
 385         if (cause & EC_SCI_SRC_ACPWR)
 386                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 387         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 388                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 389 }
 390
 391 static int __init olpc_bat_init(void)
 392 {
 393         int ret = 0;
 394         uint8_t status;
 395
 396         if (!olpc_platform_info.ecver)
 397                 return -ENXIO;
 398
 399         /*
 400          * We've seen a number of EC protocol changes; this driver requires
 401          * the latest EC protocol, supported by 0x44 and above.
 402          */
 403         if (olpc_platform_info.ecver < 0x44) {
 404                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
 405                         "battery driver.\n", olpc_platform_info.ecver);
 406                 return -ENXIO;
 407         }
 408
 409         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 410         if (ret)
 411                 return ret;
 412
 413         /* Ignore the status. It doesn't actually matter */
 414
 415         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 416         if (IS_ERR(bat_pdev))
 417                 return PTR_ERR(bat_pdev);
 418
 419         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 420         if (ret)
 421                 goto ac_failed;
 422
 423         olpc_bat.name = bat_pdev->name;
 424
 425         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 426         if (ret)
 427                 goto battery_failed;
 428
 429         ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 430         if (ret)
 431                 goto eeprom_failed;
 432
 433         goto success;
 434
 435 eeprom_failed:
 436         power_supply_unregister(&olpc_bat);
 437 battery_failed:
 438         power_supply_unregister(&olpc_ac);
 439 ac_failed:
 440         platform_device_unregister(bat_pdev);
 441 success:
 442         return ret;
 443 }
 444
 445 static void __exit olpc_bat_exit(void)
 446 {
 447         device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 448         power_supply_unregister(&olpc_bat);
 449         power_supply_unregister(&olpc_ac);
 450         platform_device_unregister(bat_pdev);
 451 }
 452
 453 module_init(olpc_bat_init);
 454 module_exit(olpc_bat_exit);
 455
 456 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 457 MODULE_LICENSE("GPL");
 458 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");