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 /*********************************************************************
  88  *              Battery properties
  89  *********************************************************************/
  90 static int olpc_bat_get_property(struct power_supply *psy,
  91                                  enum power_supply_property psp,
  92                                  union power_supply_propval *val)
  93 {
  94         int ret = 0;
  95         int16_t ec_word;
  96         uint8_t ec_byte;
  97
  98         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
  99         if (ret)
 100                 return ret;
 101
 102         /* Theoretically there's a race here -- the battery could be
 103            removed immediately after we check whether it's present, and
 104            then we query for some other property of the now-absent battery.
 105            It doesn't matter though -- the EC will return the last-known
 106            information, and it's as if we just ran that _little_ bit faster
 107            and managed to read it out before the battery went away. */
 108         if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
 109                 return -ENODEV;
 110
 111         switch (psp) {
 112         case POWER_SUPPLY_PROP_STATUS:
 113                 if (olpc_platform_info.ecver > 0x44) {
 114                         if (ec_byte & BAT_STAT_CHARGING)
 115                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 116                         else if (ec_byte & BAT_STAT_DISCHARGING)
 117                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 118                         else if (ec_byte & BAT_STAT_FULL)
 119                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 120                         else /* er,... */
 121                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 122                 } else {
 123                         /* Older EC didn't report charge/discharge bits */
 124                         if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
 125                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 126                         else if (ec_byte & BAT_STAT_FULL)
 127                                 val->intval = POWER_SUPPLY_STATUS_FULL;
 128                         else /* Not _necessarily_ true but EC doesn't tell all yet */
 129                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
 130                         break;
 131                 }
 132         case POWER_SUPPLY_PROP_PRESENT:
 133                 val->intval = !!(ec_byte & BAT_STAT_PRESENT);
 134                 break;
 135
 136         case POWER_SUPPLY_PROP_HEALTH:
 137                 if (ec_byte & BAT_STAT_DESTROY)
 138                         val->intval = POWER_SUPPLY_HEALTH_DEAD;
 139                 else {
 140                         ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 141                         if (ret)
 142                                 return ret;
 143
 144                         switch (ec_byte) {
 145                         case 0:
 146                                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
 147                                 break;
 148
 149                         case BAT_ERR_OVERTEMP:
 150                                 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 151                                 break;
 152
 153                         case BAT_ERR_OVERVOLTAGE:
 154                                 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 155                                 break;
 156
 157                         case BAT_ERR_INFOFAIL:
 158                         case BAT_ERR_OUT_OF_CONTROL:
 159                         case BAT_ERR_ID_FAIL:
 160                         case BAT_ERR_ACR_FAIL:
 161                                 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 162                                 break;
 163
 164                         default:
 165                                 /* Eep. We don't know this failure code */
 166                                 return -EIO;
 167                         }
 168                 }
 169                 break;
 170
 171         case POWER_SUPPLY_PROP_MANUFACTURER:
 172                 ec_byte = BAT_ADDR_MFR_TYPE;
 173                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 174                 if (ret)
 175                         return ret;
 176
 177                 switch (ec_byte >> 4) {
 178                 case 1:
 179                         val->strval = "Gold Peak";
 180                         break;
 181                 case 2:
 182                         val->strval = "BYD";
 183                         break;
 184                 default:
 185                         val->strval = "Unknown";
 186                         break;
 187                 }
 188                 break;
 189         case POWER_SUPPLY_PROP_TECHNOLOGY:
 190                 ec_byte = BAT_ADDR_MFR_TYPE;
 191                 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 192                 if (ret)
 193                         return ret;
 194
 195                 switch (ec_byte & 0xf) {
 196                 case 1:
 197                         val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
 198                         break;
 199                 case 2:
 200                         val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
 201                         break;
 202                 default:
 203                         val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 204                         break;
 205                 }
 206                 break;
 207         case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 208                 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 209                 if (ret)
 210                         return ret;
 211
 212                 ec_word = be16_to_cpu(ec_word);
 213                 val->intval = ec_word * 9760L / 32;
 214                 break;
 215         case POWER_SUPPLY_PROP_CURRENT_AVG:
 216                 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 217                 if (ret)
 218                         return ret;
 219
 220                 ec_word = be16_to_cpu(ec_word);
 221                 val->intval = ec_word * 15625L / 120;
 222                 break;
 223         case POWER_SUPPLY_PROP_CAPACITY:
 224                 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
 225                 if (ret)
 226                         return ret;
 227                 val->intval = ec_byte;
 228                 break;
 229         case POWER_SUPPLY_PROP_TEMP:
 230                 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 231                 if (ret)
 232                         return ret;
 233                 ec_word = be16_to_cpu(ec_word);
 234                 val->intval = ec_word * 100 / 256;
 235                 break;
 236         case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 237                 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
 238                 if (ret)
 239                         return ret;
 240
 241                 ec_word = be16_to_cpu(ec_word);
 242                 val->intval = ec_word * 100 / 256;
 243                 break;
 244         default:
 245                 ret = -EINVAL;
 246                 break;
 247         }
 248
 249         return ret;
 250 }
 251
 252 static enum power_supply_property olpc_bat_props[] = {
 253         POWER_SUPPLY_PROP_STATUS,
 254         POWER_SUPPLY_PROP_PRESENT,
 255         POWER_SUPPLY_PROP_HEALTH,
 256         POWER_SUPPLY_PROP_TECHNOLOGY,
 257         POWER_SUPPLY_PROP_VOLTAGE_AVG,
 258         POWER_SUPPLY_PROP_CURRENT_AVG,
 259         POWER_SUPPLY_PROP_CAPACITY,
 260         POWER_SUPPLY_PROP_TEMP,
 261         POWER_SUPPLY_PROP_TEMP_AMBIENT,
 262         POWER_SUPPLY_PROP_MANUFACTURER,
 263 };
 264
 265 /*********************************************************************
 266  *              Initialisation
 267  *********************************************************************/
 268
 269 static struct platform_device *bat_pdev;
 270
 271 static struct power_supply olpc_bat = {
 272         .properties = olpc_bat_props,
 273         .num_properties = ARRAY_SIZE(olpc_bat_props),
 274         .get_property = olpc_bat_get_property,
 275         .use_for_apm = 1,
 276 };
 277
 278 void olpc_battery_trigger_uevent(unsigned long cause)
 279 {
 280         if (cause & EC_SCI_SRC_ACPWR)
 281                 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 282         if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 283                 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 284 }
 285
 286 static int __init olpc_bat_init(void)
 287 {
 288         int ret = 0;
 289         uint8_t status;
 290
 291         if (!olpc_platform_info.ecver)
 292                 return -ENXIO;
 293         if (olpc_platform_info.ecver < 0x43) {
 294                 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
 295                 return -ENXIO;
 296         }
 297
 298         ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 299         if (ret)
 300                 return ret;
 301
 302         /* Ignore the status. It doesn't actually matter */
 303
 304         bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 305         if (IS_ERR(bat_pdev))
 306                 return PTR_ERR(bat_pdev);
 307
 308         ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 309         if (ret)
 310                 goto ac_failed;
 311
 312         olpc_bat.name = bat_pdev->name;
 313
 314         ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 315         if (ret)
 316                 goto battery_failed;
 317
 318         olpc_register_battery_callback(&olpc_battery_trigger_uevent);
 319         goto success;
 320
 321 battery_failed:
 322         power_supply_unregister(&olpc_ac);
 323 ac_failed:
 324         platform_device_unregister(bat_pdev);
 325 success:
 326         return ret;
 327 }
 328
 329 static void __exit olpc_bat_exit(void)
 330 {
 331         olpc_deregister_battery_callback();
 332         power_supply_unregister(&olpc_bat);
 333         power_supply_unregister(&olpc_ac);
 334         platform_device_unregister(bat_pdev);
 335 }
 336
 337 module_init(olpc_bat_init);
 338 module_exit(olpc_bat_exit);
 339
 340 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 341 MODULE_LICENSE("GPL");
 342 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");