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/module.h>
  12 #include <linux/err.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/power_supply.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/sched.h>
  17 #include <asm/olpc.h>
  18
  19
  20 #define EC_BAT_VOLTAGE  0x10    /* uint16_t,    *9.76/32,    mV   */
  21 #define EC_BAT_CURRENT  0x11    /* int16_t,     *15.625/120, mA   */
  22 #define EC_BAT_ACR      0x12
  23 #define EC_BAT_TEMP     0x13    /* uint16_t,    *100/256,   °C  */
  24 #define EC_AMB_TEMP     0x14    /* uint16_t,    *100/256,   °C  */
  25 #define EC_BAT_STATUS   0x15    /* uint8_t,     bitmask */
  26 #define EC_BAT_SOC      0x16    /* uint8_t,     percentage */
  27 #define EC_BAT_SERIAL   0x17    /* uint8_t[6] */
  28 #define EC_BAT_EEPROM   0x18    /* uint8_t adr as input, uint8_t output */
  29 #define EC_BAT_ERRCODE  0x1f    /* uint8_t,     bitmask */
  30
  31 #define BAT_STAT_PRESENT        0x01
  32 #define BAT_STAT_FULL           0x02
  33 #define BAT_STAT_LOW            0x04
  34 #define BAT_STAT_DESTROY        0x08
  35 #define BAT_STAT_AC             0x10
  36 #define BAT_STAT_CHARGING       0x20
  37 #define BAT_STAT_DISCHARGING    0x40
  38
  39 #define BAT_ERR_INFOFAIL        0x02
  40 #define BAT_ERR_OVERVOLTAGE     0x04
  41 #define BAT_ERR_OVERTEMP        0x05
  42 #define BAT_ERR_GAUGESTOP       0x06
  43 #define BAT_ERR_OUT_OF_CONTROL  0x07
  44 #define BAT_ERR_ID_FAIL         0x09
  45 #define BAT_ERR_ACR_FAIL        0x10
  46
  47 #define BAT_ADDR_MFR_TYPE       0x5F
  48
  49 /*********************************************************************
  50  *              Power
  51  *********************************************************************/
  52
  53 static int olpc_ac_get_prop(struct power_supply *psy,
  54                             enum power_supply_property psp,
  55                             union power_supply_propval *val)
  56 {
  57         int ret = 0;
  58         uint8_t status;
  59
  60         switch (psp) {
  61         case POWER_SUPPLY_PROP_ONLINE:
  62                 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
  63                 if (ret)
  64                         return ret;
  65
  66                 val->intval = !!(status & BAT_STAT_AC);
  67                 break;
  68         default:
  69                 ret = -EINVAL;
  70                 break;
  71         }
  72         return ret;
  73 }
  74
  75 static enum power_supply_property olpc_ac_props[] = {
  76         POWER_SUPPLY_PROP_ONLINE,
  77 };
  78
  79 static struct power_supply olpc_ac = {
  80         .name = "olpc-ac",
  81         .type = POWER_SUPPLY_TYPE_MAINS,
  82         .properties = olpc_ac_props,
  83         .num_properties = ARRAY_SIZE(olpc_ac_props),
  84         .get_property = olpc_ac_get_prop,
  85 };
  86
  87 static char bat_serial[17]; /* Ick */
  88
  89 /*********************************************************************
  90  *              Battery properties
  91  *********************************************************************/
  92 static int olpc_bat_get_property(struct power_supply *psy,
  93                                  enum power_supply_property psp,
  94                                  union power_supply_propval *val)
  95 {
  96         int ret = 0;
  97         int16_t ec_word;
  98         uint8_t ec_byte;
  99         uint64_t ser_buf;
 100
 101         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
 102         if (ret)
 103                 return ret;
 104
 105         /* Theoretically there's a race here -- the battery could be
 106            removed immediately after we check whether it's present, and
 107            then we query for some other property of the now-absent battery.
 108            It doesn't matter though -- the EC will return the last-known
 109            information, and it's as if we just ran that _little_ bit faster
 110            and managed to read it out before the battery went away. */
 111         if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
 112                 return -ENODEV;
 113
 114         switch (psp) {
 115         case POWER_SUPPLY_PROP_STATUS:
 116                 if (olpc_platform_info.ecver > 0x44) {
 117                         if (ec_byte & BAT_STAT_CHARGING)
 118                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 119                         else if (ec_byte & BAT_STAT_DISCHARGING)
 120                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 121                         else if (ec_byte & BAT_STAT_FULL)
 122                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 123                         else /* er,... */
 124                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 125                 } else {
 126                         /* Older EC didn't report charge/discharge bits */
 127                         if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
 128                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 129                         else if (ec_byte & BAT_STAT_FULL)
 130                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 131                         else /* Not _necessarily_ true but EC doesn't tell all yet */
 132                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 133                         break;
 134                 }
 135         case POWER_SUPPLY_PROP_PRESENT:
 136                 val->intval = !!(ec_byte & BAT_STAT_PRESENT);
 137                 break;
 138
 139         case POWER_SUPPLY_PROP_HEALTH:
 140                 if (ec_byte & BAT_STAT_DESTROY)
 141                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 142                 else {
 143                         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 144                         if (ret)
 145                                 return ret;
 146
 147                         switch (ec_byte) {
 148                         case 0:
 149                                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
 150                                 break;
 151
 152                         case BAT_ERR_OVERTEMP:
 153                                 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 154                                 break;
 155
 156                         case BAT_ERR_OVERVOLTAGE:
 157                                 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 158                                 break;
 159
 160                         case BAT_ERR_INFOFAIL:
 161                         case BAT_ERR_OUT_OF_CONTROL:
 162                         case BAT_ERR_ID_FAIL:
 163                         case BAT_ERR_ACR_FAIL:
 164                                 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 165                                 break;
 166
 167                         default:
 168                                 /* Eep. We don't know this failure code */
 169                                 return -EIO;
 170                         }
 171                 }
 172                 break;
 173
 174         case POWER_SUPPLY_PROP_MANUFACTURER:
 175                 ec_byte = BAT_ADDR_MFR_TYPE;
 176                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 177                 if (ret)
 178                         return ret;
 179
 180                 switch (ec_byte >> 4) {
 181                 case 1:
 182                         val->strval = "Gold Peak";
 183                         break;
 184                 case 2:
 185                         val->strval = "BYD";
 186                         break;
 187                 default:
 188                         val->strval = "Unknown";
 189                         break;
 190                 }
 191                 break;
 192         case POWER_SUPPLY_PROP_TECHNOLOGY:
 193                 ec_byte = BAT_ADDR_MFR_TYPE;
 194                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 195                 if (ret)
 196                         return ret;
 197
 198                 switch (ec_byte & 0xf) {
 199                 case 1:
 200                         val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
 201                         break;
 202                 case 2:
 203                         val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
 204                         break;
 205                 default:
 206                         val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 207                         break;
 208                 }
 209                 break;
 210         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 211                 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 212                 if (ret)
 213                         return ret;
 214
 215                 ec_word = be16_to_cpu(ec_word);
 216                 val->intval = ec_word * 9760L / 32;
 217                 break;
 218         case POWER_SUPPLY_PROP_CURRENT_AVG:
 219                 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 220                 if (ret)
 221                         return ret;
 222
 223                 ec_word = be16_to_cpu(ec_word);
 224                 val->intval = ec_word * 15625L / 120;
 225                 break;
 226         case POWER_SUPPLY_PROP_CAPACITY:
 227                 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
 228                 if (ret)
 229                         return ret;
 230                 val->intval = ec_byte;
 231                 break;
 232         case POWER_SUPPLY_PROP_TEMP:
 233                 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 234                 if (ret)
 235                         return ret;
 236                 ec_word = be16_to_cpu(ec_word);
 237                 val->intval = ec_word * 100 / 256;
 238                 break;
 239         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 240                 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
 241                 if (ret)
 242                         return ret;
 243
 244                 ec_word = be16_to_cpu(ec_word);
 245                 val->intval = ec_word * 100 / 256;
 246                 break;
 247         case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 248                 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
 249                 if (ret)
 250                         return ret;
 251
 252                 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
 253                 val->strval = bat_serial;
 254                 break;
 255         default:
 256                 ret = -EINVAL;
 257                 break;
 258         }
 259
 260         return ret;
 261 }
 262
 263 static enum power_supply_property olpc_bat_props[] = {
 264         POWER_SUPPLY_PROP_STATUS,
 265         POWER_SUPPLY_PROP_PRESENT,
 266         POWER_SUPPLY_PROP_HEALTH,
 267         POWER_SUPPLY_PROP_TECHNOLOGY,
 268         POWER_SUPPLY_PROP_VOLTAGE_AVG,
 269         POWER_SUPPLY_PROP_CURRENT_AVG,
 270         POWER_SUPPLY_PROP_CAPACITY,
 271         POWER_SUPPLY_PROP_TEMP,
 272         POWER_SUPPLY_PROP_TEMP_AMBIENT,
 273         POWER_SUPPLY_PROP_MANUFACTURER,
 274         POWER_SUPPLY_PROP_SERIAL_NUMBER,
 275 };
 276
 277 /*********************************************************************
 278  *              Initialisation
 279  *********************************************************************/
 280
 281 static struct platform_device *bat_pdev;
 282
 283 static struct power_supply olpc_bat = {
 284         .properties = olpc_bat_props,
 285         .num_properties = ARRAY_SIZE(olpc_bat_props),
 286         .get_property = olpc_bat_get_property,
 287         .use_for_apm = 1,
 288 };
 289
 290 void olpc_battery_trigger_uevent(unsigned long cause)
 291 {
 292         if (cause & EC_SCI_SRC_ACPWR)
 293                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 294         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 295                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 296 }
 297
 298 static int __init olpc_bat_init(void)
 299 {
 300         int ret = 0;
 301         uint8_t status;
 302
 303         if (!olpc_platform_info.ecver)
 304                 return -ENXIO;
 305         if (olpc_platform_info.ecver < 0x43) {
 306                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
 307                 return -ENXIO;
 308         }
 309
 310         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 311         if (ret)
 312                 return ret;
 313
 314         /* Ignore the status. It doesn't actually matter */
 315
 316         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 317         if (IS_ERR(bat_pdev))
 318                 return PTR_ERR(bat_pdev);
 319
 320         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 321         if (ret)
 322                 goto ac_failed;
 323
 324         olpc_bat.name = bat_pdev->name;
 325
 326         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 327         if (ret)
 328                 goto battery_failed;
 329
 330         goto success;
 331
 332 battery_failed:
 333         power_supply_unregister(&olpc_ac);
 334 ac_failed:
 335         platform_device_unregister(bat_pdev);
 336 success:
 337         return ret;
 338 }
 339
 340 static void __exit olpc_bat_exit(void)
 341 {
 342         power_supply_unregister(&olpc_bat);
 343         power_supply_unregister(&olpc_ac);
 344         platform_device_unregister(bat_pdev);
 345 }
 346
 347 module_init(olpc_bat_init);
 348 module_exit(olpc_bat_exit);
 349
 350 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 351 MODULE_LICENSE("GPL");
 352 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");