olpc_battery.c revision 300bac7fb85a20b2704dc3645419057992f78565
1/*
2 * Battery driver for One Laptop Per Child board.
3 *
4 *	Copyright © 2006-2010  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/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>
20#include <asm/olpc.h>
21
22
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 */
33
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
42
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
50
51#define BAT_ADDR_MFR_TYPE	0x5F
52
53/*********************************************************************
54 *		Power
55 *********************************************************************/
56
57static int olpc_ac_get_prop(struct power_supply *psy,
58			    enum power_supply_property psp,
59			    union power_supply_propval *val)
60{
61	int ret = 0;
62	uint8_t status;
63
64	switch (psp) {
65	case POWER_SUPPLY_PROP_ONLINE:
66		ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
67		if (ret)
68			return ret;
69
70		val->intval = !!(status & BAT_STAT_AC);
71		break;
72	default:
73		ret = -EINVAL;
74		break;
75	}
76	return ret;
77}
78
79static enum power_supply_property olpc_ac_props[] = {
80	POWER_SUPPLY_PROP_ONLINE,
81};
82
83static struct power_supply olpc_ac = {
84	.name = "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,
89};
90
91static char bat_serial[17]; /* Ick */
92
93static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
94{
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;
102		else /* er,... */
103			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
104	} else {
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;
112	}
113
114	return 0;
115}
116
117static int olpc_bat_get_health(union power_supply_propval *val)
118{
119	uint8_t ec_byte;
120	int ret;
121
122	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
123	if (ret)
124		return ret;
125
126	switch (ec_byte) {
127	case 0:
128		val->intval = POWER_SUPPLY_HEALTH_GOOD;
129		break;
130
131	case BAT_ERR_OVERTEMP:
132		val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
133		break;
134
135	case BAT_ERR_OVERVOLTAGE:
136		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
137		break;
138
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;
144		break;
145
146	default:
147		/* Eep. We don't know this failure code */
148		ret = -EIO;
149	}
150
151	return ret;
152}
153
154static int olpc_bat_get_mfr(union power_supply_propval *val)
155{
156	uint8_t ec_byte;
157	int ret;
158
159	ec_byte = BAT_ADDR_MFR_TYPE;
160	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
161	if (ret)
162		return ret;
163
164	switch (ec_byte >> 4) {
165	case 1:
166		val->strval = "Gold Peak";
167		break;
168	case 2:
169		val->strval = "BYD";
170		break;
171	default:
172		val->strval = "Unknown";
173		break;
174	}
175
176	return ret;
177}
178
179static int olpc_bat_get_tech(union power_supply_propval *val)
180{
181	uint8_t ec_byte;
182	int ret;
183
184	ec_byte = BAT_ADDR_MFR_TYPE;
185	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
186	if (ret)
187		return ret;
188
189	switch (ec_byte & 0xf) {
190	case 1:
191		val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
192		break;
193	case 2:
194		val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
195		break;
196	default:
197		val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
198		break;
199	}
200
201	return ret;
202}
203
204static int olpc_bat_get_charge_full_design(union power_supply_propval *val)
205{
206	uint8_t ec_byte;
207	union power_supply_propval tech;
208	int ret, mfr;
209
210	ret = olpc_bat_get_tech(&tech);
211	if (ret)
212		return ret;
213
214	ec_byte = BAT_ADDR_MFR_TYPE;
215	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
216	if (ret)
217		return ret;
218
219	mfr = ec_byte >> 4;
220
221	switch (tech.intval) {
222	case POWER_SUPPLY_TECHNOLOGY_NiMH:
223		switch (mfr) {
224		case 1: /* Gold Peak */
225			val->intval = 3000000*.8;
226			break;
227		default:
228			return -EIO;
229		}
230		break;
231
232	case POWER_SUPPLY_TECHNOLOGY_LiFe:
233		switch (mfr) {
234		case 1: /* Gold Peak */
235			val->intval = 2800000;
236			break;
237		case 2: /* BYD */
238			val->intval = 3100000;
239			break;
240		default:
241			return -EIO;
242		}
243		break;
244
245	default:
246		return -EIO;
247	}
248
249	return ret;
250}
251
252static int olpc_bat_get_charge_now(union power_supply_propval *val)
253{
254	uint8_t soc;
255	union power_supply_propval full;
256	int ret;
257
258	ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &soc, 1);
259	if (ret)
260		return ret;
261
262	ret = olpc_bat_get_charge_full_design(&full);
263	if (ret)
264		return ret;
265
266	val->intval = soc * (full.intval / 100);
267	return 0;
268}
269
270/*********************************************************************
271 *		Battery properties
272 *********************************************************************/
273static int olpc_bat_get_property(struct power_supply *psy,
274				 enum power_supply_property psp,
275				 union power_supply_propval *val)
276{
277	int ret = 0;
278	__be16 ec_word;
279	uint8_t ec_byte;
280	__be64 ser_buf;
281
282	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
283	if (ret)
284		return ret;
285
286	/* Theoretically there's a race here -- the battery could be
287	   removed immediately after we check whether it's present, and
288	   then we query for some other property of the now-absent battery.
289	   It doesn't matter though -- the EC will return the last-known
290	   information, and it's as if we just ran that _little_ bit faster
291	   and managed to read it out before the battery went away. */
292	if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) &&
293			psp != POWER_SUPPLY_PROP_PRESENT)
294		return -ENODEV;
295
296	switch (psp) {
297	case POWER_SUPPLY_PROP_STATUS:
298		ret = olpc_bat_get_status(val, ec_byte);
299		if (ret)
300			return ret;
301		break;
302	case POWER_SUPPLY_PROP_CHARGE_TYPE:
303		if (ec_byte & BAT_STAT_TRICKLE)
304			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
305		else if (ec_byte & BAT_STAT_CHARGING)
306			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
307		else
308			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
309		break;
310	case POWER_SUPPLY_PROP_PRESENT:
311		val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
312					    BAT_STAT_TRICKLE));
313		break;
314
315	case POWER_SUPPLY_PROP_HEALTH:
316		if (ec_byte & BAT_STAT_DESTROY)
317			val->intval = POWER_SUPPLY_HEALTH_DEAD;
318		else {
319			ret = olpc_bat_get_health(val);
320			if (ret)
321				return ret;
322		}
323		break;
324
325	case POWER_SUPPLY_PROP_MANUFACTURER:
326		ret = olpc_bat_get_mfr(val);
327		if (ret)
328			return ret;
329		break;
330	case POWER_SUPPLY_PROP_TECHNOLOGY:
331		ret = olpc_bat_get_tech(val);
332		if (ret)
333			return ret;
334		break;
335	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
336	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
337		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
338		if (ret)
339			return ret;
340
341		val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32;
342		break;
343	case POWER_SUPPLY_PROP_CURRENT_AVG:
344	case POWER_SUPPLY_PROP_CURRENT_NOW:
345		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
346		if (ret)
347			return ret;
348
349		val->intval = (s16)be16_to_cpu(ec_word) * 15625L / 120;
350		break;
351	case POWER_SUPPLY_PROP_CAPACITY:
352		ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
353		if (ret)
354			return ret;
355		val->intval = ec_byte;
356		break;
357	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
358		if (ec_byte & BAT_STAT_FULL)
359			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
360		else if (ec_byte & BAT_STAT_LOW)
361			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
362		else
363			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
364		break;
365	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
366		ret = olpc_bat_get_charge_full_design(val);
367		if (ret)
368			return ret;
369		break;
370	case POWER_SUPPLY_PROP_CHARGE_NOW:
371		ret = olpc_bat_get_charge_now(val);
372		if (ret)
373			return ret;
374		break;
375	case POWER_SUPPLY_PROP_TEMP:
376		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
377		if (ret)
378			return ret;
379
380		val->intval = (s16)be16_to_cpu(ec_word) * 100 / 256;
381		break;
382	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
383		ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
384		if (ret)
385			return ret;
386
387		val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
388		break;
389	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
390		ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
391		if (ret)
392			return ret;
393
394		val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15;
395		break;
396	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
397		ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
398		if (ret)
399			return ret;
400
401		sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
402		val->strval = bat_serial;
403		break;
404	default:
405		ret = -EINVAL;
406		break;
407	}
408
409	return ret;
410}
411
412static enum power_supply_property olpc_xo1_bat_props[] = {
413	POWER_SUPPLY_PROP_STATUS,
414	POWER_SUPPLY_PROP_CHARGE_TYPE,
415	POWER_SUPPLY_PROP_PRESENT,
416	POWER_SUPPLY_PROP_HEALTH,
417	POWER_SUPPLY_PROP_TECHNOLOGY,
418	POWER_SUPPLY_PROP_VOLTAGE_AVG,
419	POWER_SUPPLY_PROP_VOLTAGE_NOW,
420	POWER_SUPPLY_PROP_CURRENT_AVG,
421	POWER_SUPPLY_PROP_CURRENT_NOW,
422	POWER_SUPPLY_PROP_CAPACITY,
423	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
424	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
425	POWER_SUPPLY_PROP_CHARGE_NOW,
426	POWER_SUPPLY_PROP_TEMP,
427	POWER_SUPPLY_PROP_TEMP_AMBIENT,
428	POWER_SUPPLY_PROP_MANUFACTURER,
429	POWER_SUPPLY_PROP_SERIAL_NUMBER,
430	POWER_SUPPLY_PROP_CHARGE_COUNTER,
431};
432
433/* XO-1.5 does not have ambient temperature property */
434static enum power_supply_property olpc_xo15_bat_props[] = {
435	POWER_SUPPLY_PROP_STATUS,
436	POWER_SUPPLY_PROP_CHARGE_TYPE,
437	POWER_SUPPLY_PROP_PRESENT,
438	POWER_SUPPLY_PROP_HEALTH,
439	POWER_SUPPLY_PROP_TECHNOLOGY,
440	POWER_SUPPLY_PROP_VOLTAGE_AVG,
441	POWER_SUPPLY_PROP_VOLTAGE_NOW,
442	POWER_SUPPLY_PROP_CURRENT_AVG,
443	POWER_SUPPLY_PROP_CURRENT_NOW,
444	POWER_SUPPLY_PROP_CAPACITY,
445	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
446	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
447	POWER_SUPPLY_PROP_CHARGE_NOW,
448	POWER_SUPPLY_PROP_TEMP,
449	POWER_SUPPLY_PROP_MANUFACTURER,
450	POWER_SUPPLY_PROP_SERIAL_NUMBER,
451	POWER_SUPPLY_PROP_CHARGE_COUNTER,
452};
453
454/* EEPROM reading goes completely around the power_supply API, sadly */
455
456#define EEPROM_START	0x20
457#define EEPROM_END	0x80
458#define EEPROM_SIZE	(EEPROM_END - EEPROM_START)
459
460static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj,
461		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
462{
463	uint8_t ec_byte;
464	int ret;
465	int i;
466
467	if (off >= EEPROM_SIZE)
468		return 0;
469	if (off + count > EEPROM_SIZE)
470		count = EEPROM_SIZE - off;
471
472	for (i = 0; i < count; i++) {
473		ec_byte = EEPROM_START + off + i;
474		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
475		if (ret) {
476			pr_err("olpc-battery: "
477			       "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
478			       ec_byte, ret);
479			return -EIO;
480		}
481	}
482
483	return count;
484}
485
486static struct bin_attribute olpc_bat_eeprom = {
487	.attr = {
488		.name = "eeprom",
489		.mode = S_IRUGO,
490	},
491	.size = 0,
492	.read = olpc_bat_eeprom_read,
493};
494
495/* Allow userspace to see the specific error value pulled from the EC */
496
497static ssize_t olpc_bat_error_read(struct device *dev,
498		struct device_attribute *attr, char *buf)
499{
500	uint8_t ec_byte;
501	ssize_t ret;
502
503	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
504	if (ret < 0)
505		return ret;
506
507	return sprintf(buf, "%d\n", ec_byte);
508}
509
510static struct device_attribute olpc_bat_error = {
511	.attr = {
512		.name = "error",
513		.mode = S_IRUGO,
514	},
515	.show = olpc_bat_error_read,
516};
517
518/*********************************************************************
519 *		Initialisation
520 *********************************************************************/
521
522static struct power_supply olpc_bat = {
523	.name = "olpc-battery",
524	.get_property = olpc_bat_get_property,
525	.use_for_apm = 1,
526};
527
528static int olpc_battery_suspend(struct platform_device *pdev,
529				pm_message_t state)
530{
531	if (device_may_wakeup(olpc_ac.dev))
532		olpc_ec_wakeup_set(EC_SCI_SRC_ACPWR);
533	else
534		olpc_ec_wakeup_clear(EC_SCI_SRC_ACPWR);
535
536	if (device_may_wakeup(olpc_bat.dev))
537		olpc_ec_wakeup_set(EC_SCI_SRC_BATTERY | EC_SCI_SRC_BATSOC
538				   | EC_SCI_SRC_BATERR);
539	else
540		olpc_ec_wakeup_clear(EC_SCI_SRC_BATTERY | EC_SCI_SRC_BATSOC
541				     | EC_SCI_SRC_BATERR);
542
543	return 0;
544}
545
546static int __devinit olpc_battery_probe(struct platform_device *pdev)
547{
548	int ret;
549	uint8_t status;
550
551	/*
552	 * We've seen a number of EC protocol changes; this driver requires
553	 * the latest EC protocol, supported by 0x44 and above.
554	 */
555	if (olpc_platform_info.ecver < 0x44) {
556		printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
557			"battery driver.\n", olpc_platform_info.ecver);
558		return -ENXIO;
559	}
560
561	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
562	if (ret)
563		return ret;
564
565	/* Ignore the status. It doesn't actually matter */
566
567	ret = power_supply_register(&pdev->dev, &olpc_ac);
568	if (ret)
569		return ret;
570
571	if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */
572		olpc_bat.properties = olpc_xo15_bat_props;
573		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props);
574	} else { /* XO-1 */
575		olpc_bat.properties = olpc_xo1_bat_props;
576		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props);
577	}
578
579	ret = power_supply_register(&pdev->dev, &olpc_bat);
580	if (ret)
581		goto battery_failed;
582
583	ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
584	if (ret)
585		goto eeprom_failed;
586
587	ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
588	if (ret)
589		goto error_failed;
590
591	if (olpc_ec_wakeup_available()) {
592		device_set_wakeup_capable(olpc_ac.dev, true);
593		device_set_wakeup_capable(olpc_bat.dev, true);
594	}
595
596	return 0;
597
598error_failed:
599	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
600eeprom_failed:
601	power_supply_unregister(&olpc_bat);
602battery_failed:
603	power_supply_unregister(&olpc_ac);
604	return ret;
605}
606
607static int __devexit olpc_battery_remove(struct platform_device *pdev)
608{
609	device_remove_file(olpc_bat.dev, &olpc_bat_error);
610	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
611	power_supply_unregister(&olpc_bat);
612	power_supply_unregister(&olpc_ac);
613	return 0;
614}
615
616static const struct of_device_id olpc_battery_ids[] __devinitconst = {
617	{ .compatible = "olpc,xo1-battery" },
618	{}
619};
620MODULE_DEVICE_TABLE(of, olpc_battery_ids);
621
622static struct platform_driver olpc_battery_driver = {
623	.driver = {
624		.name = "olpc-battery",
625		.owner = THIS_MODULE,
626		.of_match_table = olpc_battery_ids,
627	},
628	.probe = olpc_battery_probe,
629	.remove = __devexit_p(olpc_battery_remove),
630	.suspend = olpc_battery_suspend,
631};
632
633module_platform_driver(olpc_battery_driver);
634
635MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
636MODULE_LICENSE("GPL");
637MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");
638