summaryrefslogtreecommitdiffstats
path: root/drivers/power/olpc_battery.c
blob: 0cd4f15e3013ed9a7841d8010e8a4af820261701 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
/*
 * Battery driver for One Laptop Per Child board.
 *
 *	Copyright © 2006-2010  David Woodhouse <dwmw2@infradead.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <asm/olpc.h>


#define EC_BAT_VOLTAGE	0x10	/* uint16_t,	*9.76/32,    mV   */
#define EC_BAT_CURRENT	0x11	/* int16_t,	*15.625/120, mA   */
#define EC_BAT_ACR	0x12	/* int16_t,	*6250/15,    µAh  */
#define EC_BAT_TEMP	0x13	/* uint16_t,	*100/256,   °C  */
#define EC_AMB_TEMP	0x14	/* uint16_t,	*100/256,   °C  */
#define EC_BAT_STATUS	0x15	/* uint8_t,	bitmask */
#define EC_BAT_SOC	0x16	/* uint8_t,	percentage */
#define EC_BAT_SERIAL	0x17	/* uint8_t[6] */
#define EC_BAT_EEPROM	0x18	/* uint8_t adr as input, uint8_t output */
#define EC_BAT_ERRCODE	0x1f	/* uint8_t,	bitmask */

#define BAT_STAT_PRESENT	0x01
#define BAT_STAT_FULL		0x02
#define BAT_STAT_LOW		0x04
#define BAT_STAT_DESTROY	0x08
#define BAT_STAT_AC		0x10
#define BAT_STAT_CHARGING	0x20
#define BAT_STAT_DISCHARGING	0x40
#define BAT_STAT_TRICKLE	0x80

#define BAT_ERR_INFOFAIL	0x02
#define BAT_ERR_OVERVOLTAGE	0x04
#define BAT_ERR_OVERTEMP	0x05
#define BAT_ERR_GAUGESTOP	0x06
#define BAT_ERR_OUT_OF_CONTROL	0x07
#define BAT_ERR_ID_FAIL		0x09
#define BAT_ERR_ACR_FAIL	0x10

#define BAT_ADDR_MFR_TYPE	0x5F

/*********************************************************************
 *		Power
 *********************************************************************/

static int olpc_ac_get_prop(struct power_supply *psy,
			    enum power_supply_property psp,
			    union power_supply_propval *val)
{
	int ret = 0;
	uint8_t status;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
		if (ret)
			return ret;

		val->intval = !!(status & BAT_STAT_AC);
		break;
	default:
		ret = -EINVAL;
		break;
	}
	return ret;
}

static enum power_supply_property olpc_ac_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
};

static struct power_supply olpc_ac = {
	.name = "olpc-ac",
	.type = POWER_SUPPLY_TYPE_MAINS,
	.properties = olpc_ac_props,
	.num_properties = ARRAY_SIZE(olpc_ac_props),
	.get_property = olpc_ac_get_prop,
};

static char bat_serial[17]; /* Ick */

static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
{
	if (olpc_platform_info.ecver > 0x44) {
		if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE))
			val->intval = POWER_SUPPLY_STATUS_CHARGING;
		else if (ec_byte & BAT_STAT_DISCHARGING)
			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
		else if (ec_byte & BAT_STAT_FULL)
			val->intval = POWER_SUPPLY_STATUS_FULL;
		else /* er,... */
			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	} else {
		/* Older EC didn't report charge/discharge bits */
		if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
		else if (ec_byte & BAT_STAT_FULL)
			val->intval = POWER_SUPPLY_STATUS_FULL;
		else /* Not _necessarily_ true but EC doesn't tell all yet */
			val->intval = POWER_SUPPLY_STATUS_CHARGING;
	}

	return 0;
}

static int olpc_bat_get_health(union power_supply_propval *val)
{
	uint8_t ec_byte;
	int ret;

	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
	if (ret)
		return ret;

	switch (ec_byte) {
	case 0:
		val->intval = POWER_SUPPLY_HEALTH_GOOD;
		break;

	case BAT_ERR_OVERTEMP:
		val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
		break;

	case BAT_ERR_OVERVOLTAGE:
		val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
		break;

	case BAT_ERR_INFOFAIL:
	case BAT_ERR_OUT_OF_CONTROL:
	case BAT_ERR_ID_FAIL:
	case BAT_ERR_ACR_FAIL:
		val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
		break;

	default:
		/* Eep. We don't know this failure code */
		ret = -EIO;
	}

	return ret;
}

static int olpc_bat_get_mfr(union power_supply_propval *val)
{
	uint8_t ec_byte;
	int ret;

	ec_byte = BAT_ADDR_MFR_TYPE;
	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
	if (ret)
		return ret;

	switch (ec_byte >> 4) {
	case 1:
		val->strval = "Gold Peak";
		break;
	case 2:
		val->strval = "BYD";
		break;
	default:
		val->strval = "Unknown";
		break;
	}

	return ret;
}

static int olpc_bat_get_tech(union power_supply_propval *val)
{
	uint8_t ec_byte;
	int ret;

	ec_byte = BAT_ADDR_MFR_TYPE;
	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
	if (ret)
		return ret;

	switch (ec_byte & 0xf) {
	case 1:
		val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
		break;
	case 2:
		val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
		break;
	default:
		val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
		break;
	}

	return ret;
}

/*********************************************************************
 *		Battery properties
 *********************************************************************/
static int olpc_bat_get_property(struct power_supply *psy,
				 enum power_supply_property psp,
				 union power_supply_propval *val)
{
	int ret = 0;
	__be16 ec_word;
	uint8_t ec_byte;
	__be64 ser_buf;

	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
	if (ret)
		return ret;

	/* Theoretically there's a race here -- the battery could be
	   removed immediately after we check whether it's present, and
	   then we query for some other property of the now-absent battery.
	   It doesn't matter though -- the EC will return the last-known
	   information, and it's as if we just ran that _little_ bit faster
	   and managed to read it out before the battery went away. */
	if (!(ec_byte & (BAT_STAT_PRESENT | BAT_STAT_TRICKLE)) &&
			psp != POWER_SUPPLY_PROP_PRESENT)
		return -ENODEV;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
		ret = olpc_bat_get_status(val, ec_byte);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
		if (ec_byte & BAT_STAT_TRICKLE)
			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
		else if (ec_byte & BAT_STAT_CHARGING)
			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
		else
			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
		break;
	case POWER_SUPPLY_PROP_PRESENT:
		val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
					    BAT_STAT_TRICKLE));
		break;

	case POWER_SUPPLY_PROP_HEALTH:
		if (ec_byte & BAT_STAT_DESTROY)
			val->intval = POWER_SUPPLY_HEALTH_DEAD;
		else {
			ret = olpc_bat_get_health(val);
			if (ret)
				return ret;
		}
		break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
		ret = olpc_bat_get_mfr(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
		ret = olpc_bat_get_tech(val);
		if (ret)
			return ret;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32;
		break;
	case POWER_SUPPLY_PROP_CURRENT_AVG:
		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (s16)be16_to_cpu(ec_word) * 15625L / 120;
		break;
	case POWER_SUPPLY_PROP_CAPACITY:
		ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
		if (ret)
			return ret;
		val->intval = ec_byte;
		break;
	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
		if (ec_byte & BAT_STAT_FULL)
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
		else if (ec_byte & BAT_STAT_LOW)
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
		else
			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
		break;
	case POWER_SUPPLY_PROP_TEMP:
		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (s16)be16_to_cpu(ec_word) * 100 / 256;
		break;
	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
		ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
		break;
	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
		ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
		if (ret)
			return ret;

		val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15;
		break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
		ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
		if (ret)
			return ret;

		sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
		val->strval = bat_serial;
		break;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static enum power_supply_property olpc_xo1_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_TEMP_AMBIENT,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_CHARGE_COUNTER,
};

/* XO-1.5 does not have ambient temperature property */
static enum power_supply_property olpc_xo15_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_CHARGE_COUNTER,
};

/* EEPROM reading goes completely around the power_supply API, sadly */

#define EEPROM_START	0x20
#define EEPROM_END	0x80
#define EEPROM_SIZE	(EEPROM_END - EEPROM_START)

static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj,
		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
{
	uint8_t ec_byte;
	int ret;
	int i;

	if (off >= EEPROM_SIZE)
		return 0;
	if (off + count > EEPROM_SIZE)
		count = EEPROM_SIZE - off;

	for (i = 0; i < count; i++) {
		ec_byte = EEPROM_START + off + i;
		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
		if (ret) {
			pr_err("olpc-battery: "
			       "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
			       ec_byte, ret);
			return -EIO;
		}
	}

	return count;
}

static struct bin_attribute olpc_bat_eeprom = {
	.attr = {
		.name = "eeprom",
		.mode = S_IRUGO,
	},
	.size = 0,
	.read = olpc_bat_eeprom_read,
};

/* Allow userspace to see the specific error value pulled from the EC */

static ssize_t olpc_bat_error_read(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	uint8_t ec_byte;
	ssize_t ret;

	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", ec_byte);
}

static struct device_attribute olpc_bat_error = {
	.attr = {
		.name = "error",
		.mode = S_IRUGO,
	},
	.show = olpc_bat_error_read,
};

/*********************************************************************
 *		Initialisation
 *********************************************************************/

static struct platform_device *bat_pdev;

static struct power_supply olpc_bat = {
	.get_property = olpc_bat_get_property,
	.use_for_apm = 1,
};

void olpc_battery_trigger_uevent(unsigned long cause)
{
	if (cause & EC_SCI_SRC_ACPWR)
		kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
	if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
		kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
}

static int __init olpc_bat_init(void)
{
	int ret = 0;
	uint8_t status;

	if (!olpc_platform_info.ecver)
		return -ENXIO;

	/*
	 * We've seen a number of EC protocol changes; this driver requires
	 * the latest EC protocol, supported by 0x44 and above.
	 */
	if (olpc_platform_info.ecver < 0x44) {
		printk(KERN_NOTICE "OLPC EC version 0x%02x too old for "
			"battery driver.\n", olpc_platform_info.ecver);
		return -ENXIO;
	}

	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
	if (ret)
		return ret;

	/* Ignore the status. It doesn't actually matter */

	bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
	if (IS_ERR(bat_pdev))
		return PTR_ERR(bat_pdev);

	ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
	if (ret)
		goto ac_failed;

	olpc_bat.name = bat_pdev->name;
	if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */
		olpc_bat.properties = olpc_xo15_bat_props;
		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props);
	} else { /* XO-1 */
		olpc_bat.properties = olpc_xo1_bat_props;
		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props);
	}

	ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
	if (ret)
		goto battery_failed;

	ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
	if (ret)
		goto eeprom_failed;

	ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
	if (ret)
		goto error_failed;

	goto success;

error_failed:
	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
eeprom_failed:
	power_supply_unregister(&olpc_bat);
battery_failed:
	power_supply_unregister(&olpc_ac);
ac_failed:
	platform_device_unregister(bat_pdev);
success:
	return ret;
}

static void __exit olpc_bat_exit(void)
{
	device_remove_file(olpc_bat.dev, &olpc_bat_error);
	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
	power_supply_unregister(&olpc_bat);
	power_supply_unregister(&olpc_ac);
	platform_device_unregister(bat_pdev);
}

module_init(olpc_bat_init);
module_exit(olpc_bat_exit);

MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");