2 * Battery driver for One Laptop Per Child board.
4 * Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
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.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/err.h>
15 #include <linux/device.h>
16 #include <linux/platform_device.h>
17 #include <linux/power_supply.h>
18 #include <linux/jiffies.h>
19 #include <linux/sched.h>
23 #define EC_BAT_VOLTAGE 0x10 /* uint16_t, *9.76/32, mV */
24 #define EC_BAT_CURRENT 0x11 /* int16_t, *15.625/120, mA */
25 #define EC_BAT_ACR 0x12 /* int16_t, *6250/15, µAh */
26 #define EC_BAT_TEMP 0x13 /* uint16_t, *100/256, °C */
27 #define EC_AMB_TEMP 0x14 /* uint16_t, *100/256, °C */
28 #define EC_BAT_STATUS 0x15 /* uint8_t, bitmask */
29 #define EC_BAT_SOC 0x16 /* uint8_t, percentage */
30 #define EC_BAT_SERIAL 0x17 /* uint8_t[6] */
31 #define EC_BAT_EEPROM 0x18 /* uint8_t adr as input, uint8_t output */
32 #define EC_BAT_ERRCODE 0x1f /* uint8_t, bitmask */
34 #define BAT_STAT_PRESENT 0x01
35 #define BAT_STAT_FULL 0x02
36 #define BAT_STAT_LOW 0x04
37 #define BAT_STAT_DESTROY 0x08
38 #define BAT_STAT_AC 0x10
39 #define BAT_STAT_CHARGING 0x20
40 #define BAT_STAT_DISCHARGING 0x40
41 #define BAT_STAT_TRICKLE 0x80
43 #define BAT_ERR_INFOFAIL 0x02
44 #define BAT_ERR_OVERVOLTAGE 0x04
45 #define BAT_ERR_OVERTEMP 0x05
46 #define BAT_ERR_GAUGESTOP 0x06
47 #define BAT_ERR_OUT_OF_CONTROL 0x07
48 #define BAT_ERR_ID_FAIL 0x09
49 #define BAT_ERR_ACR_FAIL 0x10
51 #define BAT_ADDR_MFR_TYPE 0x5F
53 /*********************************************************************
55 *********************************************************************/
57 static int olpc_ac_get_prop(struct power_supply *psy,
58 enum power_supply_property psp,
59 union power_supply_propval *val)
65 case POWER_SUPPLY_PROP_ONLINE:
66 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
70 val->intval = !!(status & BAT_STAT_AC);
79 static enum power_supply_property olpc_ac_props[] = {
80 POWER_SUPPLY_PROP_ONLINE,
83 static struct power_supply olpc_ac = {
85 .type = POWER_SUPPLY_TYPE_MAINS,
86 .properties = olpc_ac_props,
87 .num_properties = ARRAY_SIZE(olpc_ac_props),
88 .get_property = olpc_ac_get_prop,
91 static char bat_serial[17]; /* Ick */
93 static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
95 if (olpc_platform_info.ecver > 0x44) {
96 if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE))
97 val->intval = POWER_SUPPLY_STATUS_CHARGING;
98 else if (ec_byte & BAT_STAT_DISCHARGING)
99 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
100 else if (ec_byte & BAT_STAT_FULL)
101 val->intval = POWER_SUPPLY_STATUS_FULL;
103 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
105 /* Older EC didn't report charge/discharge bits */
106 if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
107 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
108 else if (ec_byte & BAT_STAT_FULL)
109 val->intval = POWER_SUPPLY_STATUS_FULL;
110 else /* Not _necessarily_ true but EC doesn't tell all yet */
111 val->intval = POWER_SUPPLY_STATUS_CHARGING;
117 static int olpc_bat_get_health(union power_supply_propval *val)
122 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
128 val->intval = POWER_SUPPLY_HEALTH_GOOD;
131 case BAT_ERR_OVERTEMP:
132 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
135 case BAT_ERR_OVERVOLTAGE:
136 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
139 case BAT_ERR_INFOFAIL:
140 case BAT_ERR_OUT_OF_CONTROL:
141 case BAT_ERR_ID_FAIL:
142 case BAT_ERR_ACR_FAIL:
143 val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
147 /* Eep. We don't know this failure code */
154 static int olpc_bat_get_mfr(union power_supply_propval *val)
159 ec_byte = BAT_ADDR_MFR_TYPE;
160 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
164 switch (ec_byte >> 4) {
166 val->strval = "Gold Peak";
172 val->strval = "Unknown";
179 static int olpc_bat_get_tech(union power_supply_propval *val)
184 ec_byte = BAT_ADDR_MFR_TYPE;
185 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
189 switch (ec_byte & 0xf) {
191 val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
194 val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
197 val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
204 /*********************************************************************
206 *********************************************************************/
207 static int olpc_bat_get_property(struct power_supply *psy,
208 enum power_supply_property psp,
209 union power_supply_propval *val)
216 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
220 /* Theoretically there's a race here -- the battery could be
221 removed immediately after we check whether it's present, and
222 then we query for some other property of the now-absent battery.
223 It doesn't matter though -- the EC will return the last-known
224 information, and it's as if we just ran that _little_ bit faster
225 and managed to read it out before the battery went away. */
226 if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) &&
227 psp != POWER_SUPPLY_PROP_PRESENT)
231 case POWER_SUPPLY_PROP_STATUS:
232 ret = olpc_bat_get_status(val, ec_byte);
236 case POWER_SUPPLY_PROP_CHARGE_TYPE:
237 if (ec_byte & BAT_STAT_TRICKLE)
238 val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
239 else if (ec_byte & BAT_STAT_CHARGING)
240 val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
242 val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
244 case POWER_SUPPLY_PROP_PRESENT:
245 val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
249 case POWER_SUPPLY_PROP_HEALTH:
250 if (ec_byte & BAT_STAT_DESTROY)
251 val->intval = POWER_SUPPLY_HEALTH_DEAD;
253 ret = olpc_bat_get_health(val);
259 case POWER_SUPPLY_PROP_MANUFACTURER:
260 ret = olpc_bat_get_mfr(val);
264 case POWER_SUPPLY_PROP_TECHNOLOGY:
265 ret = olpc_bat_get_tech(val);
269 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
270 ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
274 val->intval = (int)be16_to_cpu(ec_word) * 9760L / 32;
276 case POWER_SUPPLY_PROP_CURRENT_AVG:
277 ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
281 val->intval = (int)be16_to_cpu(ec_word) * 15625L / 120;
283 case POWER_SUPPLY_PROP_CAPACITY:
284 ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
287 val->intval = ec_byte;
289 case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
290 if (ec_byte & BAT_STAT_FULL)
291 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
292 else if (ec_byte & BAT_STAT_LOW)
293 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
295 val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
297 case POWER_SUPPLY_PROP_TEMP:
298 ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
302 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
304 case POWER_SUPPLY_PROP_TEMP_AMBIENT:
305 ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
309 val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
311 case POWER_SUPPLY_PROP_CHARGE_COUNTER:
312 ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
316 val->intval = (int)be16_to_cpu(ec_word) * 6250 / 15;
318 case POWER_SUPPLY_PROP_SERIAL_NUMBER:
319 ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
323 sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
324 val->strval = bat_serial;
334 static enum power_supply_property olpc_bat_props[] = {
335 POWER_SUPPLY_PROP_STATUS,
336 POWER_SUPPLY_PROP_CHARGE_TYPE,
337 POWER_SUPPLY_PROP_PRESENT,
338 POWER_SUPPLY_PROP_HEALTH,
339 POWER_SUPPLY_PROP_TECHNOLOGY,
340 POWER_SUPPLY_PROP_VOLTAGE_AVG,
341 POWER_SUPPLY_PROP_CURRENT_AVG,
342 POWER_SUPPLY_PROP_CAPACITY,
343 POWER_SUPPLY_PROP_CAPACITY_LEVEL,
344 POWER_SUPPLY_PROP_TEMP,
345 POWER_SUPPLY_PROP_TEMP_AMBIENT,
346 POWER_SUPPLY_PROP_MANUFACTURER,
347 POWER_SUPPLY_PROP_SERIAL_NUMBER,
348 POWER_SUPPLY_PROP_CHARGE_COUNTER,
351 /* EEPROM reading goes completely around the power_supply API, sadly */
353 #define EEPROM_START 0x20
354 #define EEPROM_END 0x80
355 #define EEPROM_SIZE (EEPROM_END - EEPROM_START)
357 static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj,
358 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
364 if (off >= EEPROM_SIZE)
366 if (off + count > EEPROM_SIZE)
367 count = EEPROM_SIZE - off;
369 for (i = 0; i < count; i++) {
370 ec_byte = EEPROM_START + off + i;
371 ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
373 pr_err("olpc-battery: "
374 "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
383 static struct bin_attribute olpc_bat_eeprom = {
387 .owner = THIS_MODULE,
390 .read = olpc_bat_eeprom_read,
393 /* Allow userspace to see the specific error value pulled from the EC */
395 static ssize_t olpc_bat_error_read(struct device *dev,
396 struct device_attribute *attr, char *buf)
401 ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
405 return sprintf(buf, "%d\n", ec_byte);
408 static struct device_attribute olpc_bat_error = {
413 .show = olpc_bat_error_read,
416 /*********************************************************************
418 *********************************************************************/
420 static struct platform_device *bat_pdev;
422 static struct power_supply olpc_bat = {
423 .properties = olpc_bat_props,
424 .num_properties = ARRAY_SIZE(olpc_bat_props),
425 .get_property = olpc_bat_get_property,
429 void olpc_battery_trigger_uevent(unsigned long cause)
431 if (cause & EC_SCI_SRC_ACPWR)
432 kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
433 if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
434 kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
437 static int __init olpc_bat_init(void)
442 if (!olpc_platform_info.ecver)
446 * We've seen a number of EC protocol changes; this driver requires
447 * the latest EC protocol, supported by 0x44 and above.
449 if (olpc_platform_info.ecver < 0x44) {
450 printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
451 "battery driver.\n", olpc_platform_info.ecver);
455 ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
459 /* Ignore the status. It doesn't actually matter */
461 bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
462 if (IS_ERR(bat_pdev))
463 return PTR_ERR(bat_pdev);
465 ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
469 olpc_bat.name = bat_pdev->name;
471 ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
475 ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
479 ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
486 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
488 power_supply_unregister(&olpc_bat);
490 power_supply_unregister(&olpc_ac);
492 platform_device_unregister(bat_pdev);
497 static void __exit olpc_bat_exit(void)
499 device_remove_file(olpc_bat.dev, &olpc_bat_error);
500 device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
501 power_supply_unregister(&olpc_bat);
502 power_supply_unregister(&olpc_ac);
503 platform_device_unregister(bat_pdev);
506 module_init(olpc_bat_init);
507 module_exit(olpc_bat_exit);
509 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
510 MODULE_LICENSE("GPL");
511 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");