olpc_battery.c revision 484d6d50cca3941db6e063113d124333aed0abc0
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 53static 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 75static enum power_supply_property olpc_ac_props[] = { 76 POWER_SUPPLY_PROP_ONLINE, 77}; 78 79static 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 87static char bat_serial[17]; /* Ick */ 88 89static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte) 90{ 91 if (olpc_platform_info.ecver > 0x44) { 92 if (ec_byte & BAT_STAT_CHARGING) 93 val->intval = POWER_SUPPLY_STATUS_CHARGING; 94 else if (ec_byte & BAT_STAT_DISCHARGING) 95 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 96 else if (ec_byte & BAT_STAT_FULL) 97 val->intval = POWER_SUPPLY_STATUS_FULL; 98 else /* er,... */ 99 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 100 } else { 101 /* Older EC didn't report charge/discharge bits */ 102 if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */ 103 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 104 else if (ec_byte & BAT_STAT_FULL) 105 val->intval = POWER_SUPPLY_STATUS_FULL; 106 else /* Not _necessarily_ true but EC doesn't tell all yet */ 107 val->intval = POWER_SUPPLY_STATUS_CHARGING; 108 } 109 110 return 0; 111} 112 113static int olpc_bat_get_health(union power_supply_propval *val) 114{ 115 uint8_t ec_byte; 116 int ret; 117 118 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1); 119 if (ret) 120 return ret; 121 122 switch (ec_byte) { 123 case 0: 124 val->intval = POWER_SUPPLY_HEALTH_GOOD; 125 break; 126 127 case BAT_ERR_OVERTEMP: 128 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; 129 break; 130 131 case BAT_ERR_OVERVOLTAGE: 132 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE; 133 break; 134 135 case BAT_ERR_INFOFAIL: 136 case BAT_ERR_OUT_OF_CONTROL: 137 case BAT_ERR_ID_FAIL: 138 case BAT_ERR_ACR_FAIL: 139 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE; 140 break; 141 142 default: 143 /* Eep. We don't know this failure code */ 144 ret = -EIO; 145 } 146 147 return ret; 148} 149 150static int olpc_bat_get_mfr(union power_supply_propval *val) 151{ 152 uint8_t ec_byte; 153 int ret; 154 155 ec_byte = BAT_ADDR_MFR_TYPE; 156 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1); 157 if (ret) 158 return ret; 159 160 switch (ec_byte >> 4) { 161 case 1: 162 val->strval = "Gold Peak"; 163 break; 164 case 2: 165 val->strval = "BYD"; 166 break; 167 default: 168 val->strval = "Unknown"; 169 break; 170 } 171 172 return ret; 173} 174 175static int olpc_bat_get_tech(union power_supply_propval *val) 176{ 177 uint8_t ec_byte; 178 int ret; 179 180 ec_byte = BAT_ADDR_MFR_TYPE; 181 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1); 182 if (ret) 183 return ret; 184 185 switch (ec_byte & 0xf) { 186 case 1: 187 val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH; 188 break; 189 case 2: 190 val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe; 191 break; 192 default: 193 val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN; 194 break; 195 } 196 197 return ret; 198} 199 200/********************************************************************* 201 * Battery properties 202 *********************************************************************/ 203static int olpc_bat_get_property(struct power_supply *psy, 204 enum power_supply_property psp, 205 union power_supply_propval *val) 206{ 207 int ret = 0; 208 int16_t ec_word; 209 uint8_t ec_byte; 210 uint64_t ser_buf; 211 212 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1); 213 if (ret) 214 return ret; 215 216 /* Theoretically there's a race here -- the battery could be 217 removed immediately after we check whether it's present, and 218 then we query for some other property of the now-absent battery. 219 It doesn't matter though -- the EC will return the last-known 220 information, and it's as if we just ran that _little_ bit faster 221 and managed to read it out before the battery went away. */ 222 if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT) 223 return -ENODEV; 224 225 switch (psp) { 226 case POWER_SUPPLY_PROP_STATUS: 227 ret = olpc_bat_get_status(val, ec_byte); 228 if (ret) 229 return ret; 230 break; 231 case POWER_SUPPLY_PROP_PRESENT: 232 val->intval = !!(ec_byte & BAT_STAT_PRESENT); 233 break; 234 235 case POWER_SUPPLY_PROP_HEALTH: 236 if (ec_byte & BAT_STAT_DESTROY) 237 val->intval = POWER_SUPPLY_HEALTH_DEAD; 238 else { 239 ret = olpc_bat_get_health(val); 240 if (ret) 241 return ret; 242 } 243 break; 244 245 case POWER_SUPPLY_PROP_MANUFACTURER: 246 ret = olpc_bat_get_mfr(val); 247 if (ret) 248 return ret; 249 break; 250 case POWER_SUPPLY_PROP_TECHNOLOGY: 251 ret = olpc_bat_get_tech(val); 252 if (ret) 253 return ret; 254 break; 255 case POWER_SUPPLY_PROP_VOLTAGE_AVG: 256 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2); 257 if (ret) 258 return ret; 259 260 ec_word = be16_to_cpu(ec_word); 261 val->intval = 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 ec_word = be16_to_cpu(ec_word); 269 val->intval = ec_word * 15625L / 120; 270 break; 271 case POWER_SUPPLY_PROP_CAPACITY: 272 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1); 273 if (ret) 274 return ret; 275 val->intval = ec_byte; 276 break; 277 case POWER_SUPPLY_PROP_TEMP: 278 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2); 279 if (ret) 280 return ret; 281 ec_word = be16_to_cpu(ec_word); 282 val->intval = ec_word * 100 / 256; 283 break; 284 case POWER_SUPPLY_PROP_TEMP_AMBIENT: 285 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2); 286 if (ret) 287 return ret; 288 289 ec_word = be16_to_cpu(ec_word); 290 val->intval = ec_word * 100 / 256; 291 break; 292 case POWER_SUPPLY_PROP_SERIAL_NUMBER: 293 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8); 294 if (ret) 295 return ret; 296 297 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf)); 298 val->strval = bat_serial; 299 break; 300 default: 301 ret = -EINVAL; 302 break; 303 } 304 305 return ret; 306} 307 308static enum power_supply_property olpc_bat_props[] = { 309 POWER_SUPPLY_PROP_STATUS, 310 POWER_SUPPLY_PROP_PRESENT, 311 POWER_SUPPLY_PROP_HEALTH, 312 POWER_SUPPLY_PROP_TECHNOLOGY, 313 POWER_SUPPLY_PROP_VOLTAGE_AVG, 314 POWER_SUPPLY_PROP_CURRENT_AVG, 315 POWER_SUPPLY_PROP_CAPACITY, 316 POWER_SUPPLY_PROP_TEMP, 317 POWER_SUPPLY_PROP_TEMP_AMBIENT, 318 POWER_SUPPLY_PROP_MANUFACTURER, 319 POWER_SUPPLY_PROP_SERIAL_NUMBER, 320}; 321 322/* EEPROM reading goes completely around the power_supply API, sadly */ 323 324#define EEPROM_START 0x20 325#define EEPROM_END 0x80 326#define EEPROM_SIZE (EEPROM_END - EEPROM_START) 327 328static ssize_t olpc_bat_eeprom_read(struct kobject *kobj, 329 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 330{ 331 uint8_t ec_byte; 332 int ret, end; 333 334 if (off >= EEPROM_SIZE) 335 return 0; 336 if (off + count > EEPROM_SIZE) 337 count = EEPROM_SIZE - off; 338 339 end = EEPROM_START + off + count; 340 for (ec_byte = EEPROM_START + off; ec_byte < end; ec_byte++) { 341 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, 342 &buf[ec_byte - EEPROM_START], 1); 343 if (ret) { 344 printk(KERN_ERR "olpc-battery: EC command " 345 "EC_BAT_EEPROM @ 0x%x failed -" 346 " %d!\n", ec_byte, ret); 347 return -EIO; 348 } 349 } 350 351 return count; 352} 353 354static struct bin_attribute olpc_bat_eeprom = { 355 .attr = { 356 .name = "eeprom", 357 .mode = S_IRUGO, 358 .owner = THIS_MODULE, 359 }, 360 .size = 0, 361 .read = olpc_bat_eeprom_read, 362}; 363 364/********************************************************************* 365 * Initialisation 366 *********************************************************************/ 367 368static struct platform_device *bat_pdev; 369 370static struct power_supply olpc_bat = { 371 .properties = olpc_bat_props, 372 .num_properties = ARRAY_SIZE(olpc_bat_props), 373 .get_property = olpc_bat_get_property, 374 .use_for_apm = 1, 375}; 376 377void olpc_battery_trigger_uevent(unsigned long cause) 378{ 379 if (cause & EC_SCI_SRC_ACPWR) 380 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE); 381 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY)) 382 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE); 383} 384 385static int __init olpc_bat_init(void) 386{ 387 int ret = 0; 388 uint8_t status; 389 390 if (!olpc_platform_info.ecver) 391 return -ENXIO; 392 393 /* 394 * We've seen a number of EC protocol changes; this driver requires 395 * the latest EC protocol, supported by 0x44 and above. 396 */ 397 if (olpc_platform_info.ecver < 0x44) { 398 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for " 399 "battery driver.\n", olpc_platform_info.ecver); 400 return -ENXIO; 401 } 402 403 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1); 404 if (ret) 405 return ret; 406 407 /* Ignore the status. It doesn't actually matter */ 408 409 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0); 410 if (IS_ERR(bat_pdev)) 411 return PTR_ERR(bat_pdev); 412 413 ret = power_supply_register(&bat_pdev->dev, &olpc_ac); 414 if (ret) 415 goto ac_failed; 416 417 olpc_bat.name = bat_pdev->name; 418 419 ret = power_supply_register(&bat_pdev->dev, &olpc_bat); 420 if (ret) 421 goto battery_failed; 422 423 ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 424 if (ret) 425 goto eeprom_failed; 426 427 goto success; 428 429eeprom_failed: 430 power_supply_unregister(&olpc_bat); 431battery_failed: 432 power_supply_unregister(&olpc_ac); 433ac_failed: 434 platform_device_unregister(bat_pdev); 435success: 436 return ret; 437} 438 439static void __exit olpc_bat_exit(void) 440{ 441 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom); 442 power_supply_unregister(&olpc_bat); 443 power_supply_unregister(&olpc_ac); 444 platform_device_unregister(bat_pdev); 445} 446 447module_init(olpc_bat_init); 448module_exit(olpc_bat_exit); 449 450MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 451MODULE_LICENSE("GPL"); 452MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine"); 453