olpc_battery.c revision 3ef0e1f8cad0a851b3dbf91802b14af7dd780352
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_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 252static 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 269static struct platform_device *bat_pdev; 270 271static 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 278void 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 286static 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 goto success; 319 320battery_failed: 321 power_supply_unregister(&olpc_ac); 322ac_failed: 323 platform_device_unregister(bat_pdev); 324success: 325 return ret; 326} 327 328static void __exit olpc_bat_exit(void) 329{ 330 power_supply_unregister(&olpc_bat); 331 power_supply_unregister(&olpc_ac); 332 platform_device_unregister(bat_pdev); 333} 334 335module_init(olpc_bat_init); 336module_exit(olpc_bat_exit); 337 338MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 339MODULE_LICENSE("GPL"); 340MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine"); 341