olpc_battery.c revision fb972873a767220333ffb509de8d9131336e212c
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 87/********************************************************************* 88 * Battery properties 89 *********************************************************************/ 90static 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_CAPACITY_LEVEL: 230 if (ec_byte & BAT_STAT_FULL) 231 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL; 232 else if (ec_byte & BAT_STAT_LOW) 233 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW; 234 else 235 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL; 236 break; 237 case POWER_SUPPLY_PROP_TEMP: 238 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2); 239 if (ret) 240 return ret; 241 ec_word = be16_to_cpu(ec_word); 242 val->intval = ec_word * 100 / 256; 243 break; 244 case POWER_SUPPLY_PROP_TEMP_AMBIENT: 245 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2); 246 if (ret) 247 return ret; 248 249 ec_word = be16_to_cpu(ec_word); 250 val->intval = ec_word * 100 / 256; 251 break; 252 default: 253 ret = -EINVAL; 254 break; 255 } 256 257 return ret; 258} 259 260static enum power_supply_property olpc_bat_props[] = { 261 POWER_SUPPLY_PROP_STATUS, 262 POWER_SUPPLY_PROP_PRESENT, 263 POWER_SUPPLY_PROP_HEALTH, 264 POWER_SUPPLY_PROP_TECHNOLOGY, 265 POWER_SUPPLY_PROP_VOLTAGE_AVG, 266 POWER_SUPPLY_PROP_CURRENT_AVG, 267 POWER_SUPPLY_PROP_CAPACITY, 268 POWER_SUPPLY_PROP_CAPACITY_LEVEL, 269 POWER_SUPPLY_PROP_TEMP, 270 POWER_SUPPLY_PROP_TEMP_AMBIENT, 271 POWER_SUPPLY_PROP_MANUFACTURER, 272}; 273 274/********************************************************************* 275 * Initialisation 276 *********************************************************************/ 277 278static struct platform_device *bat_pdev; 279 280static struct power_supply olpc_bat = { 281 .properties = olpc_bat_props, 282 .num_properties = ARRAY_SIZE(olpc_bat_props), 283 .get_property = olpc_bat_get_property, 284 .use_for_apm = 1, 285}; 286 287void olpc_battery_trigger_uevent(unsigned long cause) 288{ 289 if (cause & EC_SCI_SRC_ACPWR) 290 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE); 291 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY)) 292 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE); 293} 294 295static int __init olpc_bat_init(void) 296{ 297 int ret = 0; 298 uint8_t status; 299 300 if (!olpc_platform_info.ecver) 301 return -ENXIO; 302 if (olpc_platform_info.ecver < 0x43) { 303 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver); 304 return -ENXIO; 305 } 306 307 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1); 308 if (ret) 309 return ret; 310 311 /* Ignore the status. It doesn't actually matter */ 312 313 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0); 314 if (IS_ERR(bat_pdev)) 315 return PTR_ERR(bat_pdev); 316 317 ret = power_supply_register(&bat_pdev->dev, &olpc_ac); 318 if (ret) 319 goto ac_failed; 320 321 olpc_bat.name = bat_pdev->name; 322 323 ret = power_supply_register(&bat_pdev->dev, &olpc_bat); 324 if (ret) 325 goto battery_failed; 326 327 olpc_register_battery_callback(&olpc_battery_trigger_uevent); 328 goto success; 329 330battery_failed: 331 power_supply_unregister(&olpc_ac); 332ac_failed: 333 platform_device_unregister(bat_pdev); 334success: 335 return ret; 336} 337 338static void __exit olpc_bat_exit(void) 339{ 340 olpc_deregister_battery_callback(); 341 power_supply_unregister(&olpc_bat); 342 power_supply_unregister(&olpc_ac); 343 platform_device_unregister(bat_pdev); 344 return; 345} 346 347module_init(olpc_bat_init); 348module_exit(olpc_bat_exit); 349 350MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 351MODULE_LICENSE("GPL"); 352MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine"); 353