linux/drivers/power/olpc_battery.c
<<
>>
Prefs
   1/*
   2 * Battery driver for One Laptop Per Child board.
   3 *
   4 *      Copyright \xC2\xA9 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,    \xC2\xB5Ah  */
  26#define EC_BAT_TEMP     0x13    /* uint16_t,    *100/256,   \xC2\xB0C  */
  27#define EC_AMB_TEMP     0x14    /* uint16_t,    *100/256,   \xC2\xB0C  */
  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_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
 357static ssize_t olpc_bat_eeprom_read(struct file *filp, 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
 383static struct bin_attribute olpc_bat_eeprom = {
 384        .attr = {
 385                .name = "eeprom",
 386                .mode = S_IRUGO,
 387        },
 388        .size = 0,
 389        .read = olpc_bat_eeprom_read,
 390};
 391
 392/* Allow userspace to see the specific error value pulled from the EC */
 393
 394static ssize_t olpc_bat_error_read(struct device *dev,
 395                struct device_attribute *attr, char *buf)
 396{
 397        uint8_t ec_byte;
 398        ssize_t ret;
 399
 400        ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 401        if (ret < 0)
 402                return ret;
 403
 404        return sprintf(buf, "%d\n", ec_byte);
 405}
 406
 407static struct device_attribute olpc_bat_error = {
 408        .attr = {
 409                .name = "error",
 410                .mode = S_IRUGO,
 411        },
 412        .show = olpc_bat_error_read,
 413};
 414
 415/*********************************************************************
 416 *              Initialisation
 417 *********************************************************************/
 418
 419static struct platform_device *bat_pdev;
 420
 421static struct power_supply olpc_bat = {
 422        .properties = olpc_bat_props,
 423        .num_properties = ARRAY_SIZE(olpc_bat_props),
 424        .get_property = olpc_bat_get_property,
 425        .use_for_apm = 1,
 426};
 427
 428void olpc_battery_trigger_uevent(unsigned long cause)
 429{
 430        if (cause & EC_SCI_SRC_ACPWR)
 431                kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 432        if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 433                kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 434}
 435
 436static int __init olpc_bat_init(void)
 437{
 438        int ret = 0;
 439        uint8_t status;
 440
 441        if (!olpc_platform_info.ecver)
 442                return -ENXIO;
 443
 444        /*
 445         * We've seen a number of EC protocol changes; this driver requires
 446         * the latest EC protocol, supported by 0x44 and above.
 447         */
 448        if (olpc_platform_info.ecver < 0x44) {
 449                printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
 450                        "battery driver.\n", olpc_platform_info.ecver);
 451                return -ENXIO;
 452        }
 453
 454        ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 455        if (ret)
 456                return ret;
 457
 458        /* Ignore the status. It doesn't actually matter */
 459
 460        bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 461        if (IS_ERR(bat_pdev))
 462                return PTR_ERR(bat_pdev);
 463
 464        ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 465        if (ret)
 466                goto ac_failed;
 467
 468        olpc_bat.name = bat_pdev->name;
 469
 470        ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 471        if (ret)
 472                goto battery_failed;
 473
 474        ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 475        if (ret)
 476                goto eeprom_failed;
 477
 478        ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
 479        if (ret)
 480                goto error_failed;
 481
 482        goto success;
 483
 484error_failed:
 485        device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 486eeprom_failed:
 487        power_supply_unregister(&olpc_bat);
 488battery_failed:
 489        power_supply_unregister(&olpc_ac);
 490ac_failed:
 491        platform_device_unregister(bat_pdev);
 492success:
 493        return ret;
 494}
 495
 496static void __exit olpc_bat_exit(void)
 497{
 498        device_remove_file(olpc_bat.dev, &olpc_bat_error);
 499        device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 500        power_supply_unregister(&olpc_bat);
 501        power_supply_unregister(&olpc_ac);
 502        platform_device_unregister(bat_pdev);
 503}
 504
 505module_init(olpc_bat_init);
 506module_exit(olpc_bat_exit);
 507
 508MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 509MODULE_LICENSE("GPL");
 510MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");
 511