xref: /openbmc/linux/drivers/acpi/battery.c (revision 643d1f7f)
1 /*
2  *  battery.c - ACPI Battery Driver (Revision: 2.0)
3  *
4  *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
6  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
7  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27 
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/types.h>
32 #include <linux/jiffies.h>
33 
34 #ifdef CONFIG_ACPI_PROCFS_POWER
35 #include <linux/proc_fs.h>
36 #include <linux/seq_file.h>
37 #include <asm/uaccess.h>
38 #endif
39 
40 #include <acpi/acpi_bus.h>
41 #include <acpi/acpi_drivers.h>
42 
43 #ifdef CONFIG_ACPI_SYSFS_POWER
44 #include <linux/power_supply.h>
45 #endif
46 
47 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
48 
49 #define ACPI_BATTERY_COMPONENT		0x00040000
50 #define ACPI_BATTERY_CLASS		"battery"
51 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
52 #define ACPI_BATTERY_NOTIFY_STATUS	0x80
53 #define ACPI_BATTERY_NOTIFY_INFO	0x81
54 
55 #define _COMPONENT		ACPI_BATTERY_COMPONENT
56 
57 ACPI_MODULE_NAME("battery");
58 
59 MODULE_AUTHOR("Paul Diefenbaugh");
60 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
61 MODULE_DESCRIPTION("ACPI Battery Driver");
62 MODULE_LICENSE("GPL");
63 
64 static unsigned int cache_time = 1000;
65 module_param(cache_time, uint, 0644);
66 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
67 
68 #ifdef CONFIG_ACPI_PROCFS_POWER
69 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
70 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
71 
72 enum acpi_battery_files {
73 	info_tag = 0,
74 	state_tag,
75 	alarm_tag,
76 	ACPI_BATTERY_NUMFILES,
77 };
78 
79 #endif
80 
81 static const struct acpi_device_id battery_device_ids[] = {
82 	{"PNP0C0A", 0},
83 	{"", 0},
84 };
85 
86 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
87 
88 
89 struct acpi_battery {
90 	struct mutex lock;
91 #ifdef CONFIG_ACPI_SYSFS_POWER
92 	struct power_supply bat;
93 #endif
94 	struct acpi_device *device;
95 	unsigned long update_time;
96 	int current_now;
97 	int capacity_now;
98 	int voltage_now;
99 	int design_capacity;
100 	int full_charge_capacity;
101 	int technology;
102 	int design_voltage;
103 	int design_capacity_warning;
104 	int design_capacity_low;
105 	int capacity_granularity_1;
106 	int capacity_granularity_2;
107 	int alarm;
108 	char model_number[32];
109 	char serial_number[32];
110 	char type[32];
111 	char oem_info[32];
112 	int state;
113 	int power_unit;
114 	u8 alarm_present;
115 };
116 
117 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
118 
119 inline int acpi_battery_present(struct acpi_battery *battery)
120 {
121 	return battery->device->status.battery_present;
122 }
123 
124 #ifdef CONFIG_ACPI_SYSFS_POWER
125 static int acpi_battery_technology(struct acpi_battery *battery)
126 {
127 	if (!strcasecmp("NiCd", battery->type))
128 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
129 	if (!strcasecmp("NiMH", battery->type))
130 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
131 	if (!strcasecmp("LION", battery->type))
132 		return POWER_SUPPLY_TECHNOLOGY_LION;
133 	if (!strncasecmp("LI-ION", battery->type, 6))
134 		return POWER_SUPPLY_TECHNOLOGY_LION;
135 	if (!strcasecmp("LiP", battery->type))
136 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
137 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
138 }
139 
140 static int acpi_battery_get_state(struct acpi_battery *battery);
141 
142 static int acpi_battery_get_property(struct power_supply *psy,
143 				     enum power_supply_property psp,
144 				     union power_supply_propval *val)
145 {
146 	struct acpi_battery *battery = to_acpi_battery(psy);
147 
148 	if (acpi_battery_present(battery)) {
149 		/* run battery update only if it is present */
150 		acpi_battery_get_state(battery);
151 	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
152 		return -ENODEV;
153 	switch (psp) {
154 	case POWER_SUPPLY_PROP_STATUS:
155 		if (battery->state & 0x01)
156 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
157 		else if (battery->state & 0x02)
158 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
159 		else if (battery->state == 0)
160 			val->intval = POWER_SUPPLY_STATUS_FULL;
161 		else
162 			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
163 		break;
164 	case POWER_SUPPLY_PROP_PRESENT:
165 		val->intval = acpi_battery_present(battery);
166 		break;
167 	case POWER_SUPPLY_PROP_TECHNOLOGY:
168 		val->intval = acpi_battery_technology(battery);
169 		break;
170 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
171 		val->intval = battery->design_voltage * 1000;
172 		break;
173 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
174 		val->intval = battery->voltage_now * 1000;
175 		break;
176 	case POWER_SUPPLY_PROP_CURRENT_NOW:
177 		val->intval = battery->current_now * 1000;
178 		break;
179 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
180 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
181 		val->intval = battery->design_capacity * 1000;
182 		break;
183 	case POWER_SUPPLY_PROP_CHARGE_FULL:
184 	case POWER_SUPPLY_PROP_ENERGY_FULL:
185 		val->intval = battery->full_charge_capacity * 1000;
186 		break;
187 	case POWER_SUPPLY_PROP_CHARGE_NOW:
188 	case POWER_SUPPLY_PROP_ENERGY_NOW:
189 		val->intval = battery->capacity_now * 1000;
190 		break;
191 	case POWER_SUPPLY_PROP_MODEL_NAME:
192 		val->strval = battery->model_number;
193 		break;
194 	case POWER_SUPPLY_PROP_MANUFACTURER:
195 		val->strval = battery->oem_info;
196 		break;
197 	default:
198 		return -EINVAL;
199 	}
200 	return 0;
201 }
202 
203 static enum power_supply_property charge_battery_props[] = {
204 	POWER_SUPPLY_PROP_STATUS,
205 	POWER_SUPPLY_PROP_PRESENT,
206 	POWER_SUPPLY_PROP_TECHNOLOGY,
207 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
208 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
209 	POWER_SUPPLY_PROP_CURRENT_NOW,
210 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
211 	POWER_SUPPLY_PROP_CHARGE_FULL,
212 	POWER_SUPPLY_PROP_CHARGE_NOW,
213 	POWER_SUPPLY_PROP_MODEL_NAME,
214 	POWER_SUPPLY_PROP_MANUFACTURER,
215 };
216 
217 static enum power_supply_property energy_battery_props[] = {
218 	POWER_SUPPLY_PROP_STATUS,
219 	POWER_SUPPLY_PROP_PRESENT,
220 	POWER_SUPPLY_PROP_TECHNOLOGY,
221 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
222 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
223 	POWER_SUPPLY_PROP_CURRENT_NOW,
224 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
225 	POWER_SUPPLY_PROP_ENERGY_FULL,
226 	POWER_SUPPLY_PROP_ENERGY_NOW,
227 	POWER_SUPPLY_PROP_MODEL_NAME,
228 	POWER_SUPPLY_PROP_MANUFACTURER,
229 };
230 #endif
231 
232 #ifdef CONFIG_ACPI_PROCFS_POWER
233 inline char *acpi_battery_units(struct acpi_battery *battery)
234 {
235 	return (battery->power_unit)?"mA":"mW";
236 }
237 #endif
238 
239 /* --------------------------------------------------------------------------
240                                Battery Management
241    -------------------------------------------------------------------------- */
242 struct acpi_offsets {
243 	size_t offset;		/* offset inside struct acpi_sbs_battery */
244 	u8 mode;		/* int or string? */
245 };
246 
247 static struct acpi_offsets state_offsets[] = {
248 	{offsetof(struct acpi_battery, state), 0},
249 	{offsetof(struct acpi_battery, current_now), 0},
250 	{offsetof(struct acpi_battery, capacity_now), 0},
251 	{offsetof(struct acpi_battery, voltage_now), 0},
252 };
253 
254 static struct acpi_offsets info_offsets[] = {
255 	{offsetof(struct acpi_battery, power_unit), 0},
256 	{offsetof(struct acpi_battery, design_capacity), 0},
257 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
258 	{offsetof(struct acpi_battery, technology), 0},
259 	{offsetof(struct acpi_battery, design_voltage), 0},
260 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
261 	{offsetof(struct acpi_battery, design_capacity_low), 0},
262 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
263 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
264 	{offsetof(struct acpi_battery, model_number), 1},
265 	{offsetof(struct acpi_battery, serial_number), 1},
266 	{offsetof(struct acpi_battery, type), 1},
267 	{offsetof(struct acpi_battery, oem_info), 1},
268 };
269 
270 static int extract_package(struct acpi_battery *battery,
271 			   union acpi_object *package,
272 			   struct acpi_offsets *offsets, int num)
273 {
274 	int i;
275 	union acpi_object *element;
276 	if (package->type != ACPI_TYPE_PACKAGE)
277 		return -EFAULT;
278 	for (i = 0; i < num; ++i) {
279 		if (package->package.count <= i)
280 			return -EFAULT;
281 		element = &package->package.elements[i];
282 		if (offsets[i].mode) {
283 			u8 *ptr = (u8 *)battery + offsets[i].offset;
284 			if (element->type == ACPI_TYPE_STRING ||
285 			    element->type == ACPI_TYPE_BUFFER)
286 				strncpy(ptr, element->string.pointer, 32);
287 			else if (element->type == ACPI_TYPE_INTEGER) {
288 				strncpy(ptr, (u8 *)&element->integer.value,
289 					sizeof(acpi_integer));
290 				ptr[sizeof(acpi_integer)] = 0;
291 			} else return -EFAULT;
292 		} else {
293 			if (element->type == ACPI_TYPE_INTEGER) {
294 				int *x = (int *)((u8 *)battery +
295 						offsets[i].offset);
296 				*x = element->integer.value;
297 			} else return -EFAULT;
298 		}
299 	}
300 	return 0;
301 }
302 
303 static int acpi_battery_get_status(struct acpi_battery *battery)
304 {
305 	if (acpi_bus_get_status(battery->device)) {
306 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
307 		return -ENODEV;
308 	}
309 	return 0;
310 }
311 
312 static int acpi_battery_get_info(struct acpi_battery *battery)
313 {
314 	int result = -EFAULT;
315 	acpi_status status = 0;
316 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
317 
318 	if (!acpi_battery_present(battery))
319 		return 0;
320 	mutex_lock(&battery->lock);
321 	status = acpi_evaluate_object(battery->device->handle, "_BIF",
322 				      NULL, &buffer);
323 	mutex_unlock(&battery->lock);
324 
325 	if (ACPI_FAILURE(status)) {
326 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
327 		return -ENODEV;
328 	}
329 
330 	result = extract_package(battery, buffer.pointer,
331 				 info_offsets, ARRAY_SIZE(info_offsets));
332 	kfree(buffer.pointer);
333 	return result;
334 }
335 
336 static int acpi_battery_get_state(struct acpi_battery *battery)
337 {
338 	int result = 0;
339 	acpi_status status = 0;
340 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
341 
342 	if (!acpi_battery_present(battery))
343 		return 0;
344 
345 	if (battery->update_time &&
346 	    time_before(jiffies, battery->update_time +
347 			msecs_to_jiffies(cache_time)))
348 		return 0;
349 
350 	mutex_lock(&battery->lock);
351 	status = acpi_evaluate_object(battery->device->handle, "_BST",
352 				      NULL, &buffer);
353 	mutex_unlock(&battery->lock);
354 
355 	if (ACPI_FAILURE(status)) {
356 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
357 		return -ENODEV;
358 	}
359 
360 	result = extract_package(battery, buffer.pointer,
361 				 state_offsets, ARRAY_SIZE(state_offsets));
362 	battery->update_time = jiffies;
363 	kfree(buffer.pointer);
364 	return result;
365 }
366 
367 static int acpi_battery_set_alarm(struct acpi_battery *battery)
368 {
369 	acpi_status status = 0;
370 	union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
371 	struct acpi_object_list arg_list = { 1, &arg0 };
372 
373 	if (!acpi_battery_present(battery)|| !battery->alarm_present)
374 		return -ENODEV;
375 
376 	arg0.integer.value = battery->alarm;
377 
378 	mutex_lock(&battery->lock);
379 	status = acpi_evaluate_object(battery->device->handle, "_BTP",
380 				 &arg_list, NULL);
381 	mutex_unlock(&battery->lock);
382 
383 	if (ACPI_FAILURE(status))
384 		return -ENODEV;
385 
386 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
387 	return 0;
388 }
389 
390 static int acpi_battery_init_alarm(struct acpi_battery *battery)
391 {
392 	acpi_status status = AE_OK;
393 	acpi_handle handle = NULL;
394 
395 	/* See if alarms are supported, and if so, set default */
396 	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
397 	if (ACPI_FAILURE(status)) {
398 		battery->alarm_present = 0;
399 		return 0;
400 	}
401 	battery->alarm_present = 1;
402 	if (!battery->alarm)
403 		battery->alarm = battery->design_capacity_warning;
404 	return acpi_battery_set_alarm(battery);
405 }
406 
407 #ifdef CONFIG_ACPI_SYSFS_POWER
408 static ssize_t acpi_battery_alarm_show(struct device *dev,
409 					struct device_attribute *attr,
410 					char *buf)
411 {
412 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
413 	return sprintf(buf, "%d\n", battery->alarm * 1000);
414 }
415 
416 static ssize_t acpi_battery_alarm_store(struct device *dev,
417 					struct device_attribute *attr,
418 					const char *buf, size_t count)
419 {
420 	unsigned long x;
421 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
422 	if (sscanf(buf, "%ld\n", &x) == 1)
423 		battery->alarm = x/1000;
424 	if (acpi_battery_present(battery))
425 		acpi_battery_set_alarm(battery);
426 	return count;
427 }
428 
429 static struct device_attribute alarm_attr = {
430 	.attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE},
431 	.show = acpi_battery_alarm_show,
432 	.store = acpi_battery_alarm_store,
433 };
434 
435 static int sysfs_add_battery(struct acpi_battery *battery)
436 {
437 	int result;
438 
439 	if (battery->power_unit) {
440 		battery->bat.properties = charge_battery_props;
441 		battery->bat.num_properties =
442 			ARRAY_SIZE(charge_battery_props);
443 	} else {
444 		battery->bat.properties = energy_battery_props;
445 		battery->bat.num_properties =
446 			ARRAY_SIZE(energy_battery_props);
447 	}
448 
449 	battery->bat.name = acpi_device_bid(battery->device);
450 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
451 	battery->bat.get_property = acpi_battery_get_property;
452 
453 	result = power_supply_register(&battery->device->dev, &battery->bat);
454 	if (result)
455 		return result;
456 	return device_create_file(battery->bat.dev, &alarm_attr);
457 }
458 
459 static void sysfs_remove_battery(struct acpi_battery *battery)
460 {
461 	if (!battery->bat.dev)
462 		return;
463 	device_remove_file(battery->bat.dev, &alarm_attr);
464 	power_supply_unregister(&battery->bat);
465 	battery->bat.dev = NULL;
466 }
467 #endif
468 
469 static int acpi_battery_update(struct acpi_battery *battery)
470 {
471 	int result;
472 	result = acpi_battery_get_status(battery);
473 	if (result)
474 		return result;
475 #ifdef CONFIG_ACPI_SYSFS_POWER
476 	if (!acpi_battery_present(battery)) {
477 		sysfs_remove_battery(battery);
478 		battery->update_time = 0;
479 		return 0;
480 	}
481 #endif
482 	if (!battery->update_time) {
483 		result = acpi_battery_get_info(battery);
484 		if (result)
485 			return result;
486 		acpi_battery_init_alarm(battery);
487 	}
488 #ifdef CONFIG_ACPI_SYSFS_POWER
489 	if (!battery->bat.dev)
490 		sysfs_add_battery(battery);
491 #endif
492 	return acpi_battery_get_state(battery);
493 }
494 
495 /* --------------------------------------------------------------------------
496                               FS Interface (/proc)
497    -------------------------------------------------------------------------- */
498 
499 #ifdef CONFIG_ACPI_PROCFS_POWER
500 static struct proc_dir_entry *acpi_battery_dir;
501 
502 static int acpi_battery_print_info(struct seq_file *seq, int result)
503 {
504 	struct acpi_battery *battery = seq->private;
505 
506 	if (result)
507 		goto end;
508 
509 	seq_printf(seq, "present:                 %s\n",
510 		   acpi_battery_present(battery)?"yes":"no");
511 	if (!acpi_battery_present(battery))
512 		goto end;
513 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
514 		seq_printf(seq, "design capacity:         unknown\n");
515 	else
516 		seq_printf(seq, "design capacity:         %d %sh\n",
517 			   battery->design_capacity,
518 			   acpi_battery_units(battery));
519 
520 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
521 		seq_printf(seq, "last full capacity:      unknown\n");
522 	else
523 		seq_printf(seq, "last full capacity:      %d %sh\n",
524 			   battery->full_charge_capacity,
525 			   acpi_battery_units(battery));
526 
527 	seq_printf(seq, "battery technology:      %srechargeable\n",
528 		   (!battery->technology)?"non-":"");
529 
530 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
531 		seq_printf(seq, "design voltage:          unknown\n");
532 	else
533 		seq_printf(seq, "design voltage:          %d mV\n",
534 			   battery->design_voltage);
535 	seq_printf(seq, "design capacity warning: %d %sh\n",
536 		   battery->design_capacity_warning,
537 		   acpi_battery_units(battery));
538 	seq_printf(seq, "design capacity low:     %d %sh\n",
539 		   battery->design_capacity_low,
540 		   acpi_battery_units(battery));
541 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
542 		   battery->capacity_granularity_1,
543 		   acpi_battery_units(battery));
544 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
545 		   battery->capacity_granularity_2,
546 		   acpi_battery_units(battery));
547 	seq_printf(seq, "model number:            %s\n", battery->model_number);
548 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
549 	seq_printf(seq, "battery type:            %s\n", battery->type);
550 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
551       end:
552 	if (result)
553 		seq_printf(seq, "ERROR: Unable to read battery info\n");
554 	return result;
555 }
556 
557 static int acpi_battery_print_state(struct seq_file *seq, int result)
558 {
559 	struct acpi_battery *battery = seq->private;
560 
561 	if (result)
562 		goto end;
563 
564 	seq_printf(seq, "present:                 %s\n",
565 		   acpi_battery_present(battery)?"yes":"no");
566 	if (!acpi_battery_present(battery))
567 		goto end;
568 
569 	seq_printf(seq, "capacity state:          %s\n",
570 			(battery->state & 0x04)?"critical":"ok");
571 	if ((battery->state & 0x01) && (battery->state & 0x02))
572 		seq_printf(seq,
573 			   "charging state:          charging/discharging\n");
574 	else if (battery->state & 0x01)
575 		seq_printf(seq, "charging state:          discharging\n");
576 	else if (battery->state & 0x02)
577 		seq_printf(seq, "charging state:          charging\n");
578 	else
579 		seq_printf(seq, "charging state:          charged\n");
580 
581 	if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
582 		seq_printf(seq, "present rate:            unknown\n");
583 	else
584 		seq_printf(seq, "present rate:            %d %s\n",
585 			   battery->current_now, acpi_battery_units(battery));
586 
587 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
588 		seq_printf(seq, "remaining capacity:      unknown\n");
589 	else
590 		seq_printf(seq, "remaining capacity:      %d %sh\n",
591 			   battery->capacity_now, acpi_battery_units(battery));
592 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
593 		seq_printf(seq, "present voltage:         unknown\n");
594 	else
595 		seq_printf(seq, "present voltage:         %d mV\n",
596 			   battery->voltage_now);
597       end:
598 	if (result)
599 		seq_printf(seq, "ERROR: Unable to read battery state\n");
600 
601 	return result;
602 }
603 
604 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
605 {
606 	struct acpi_battery *battery = seq->private;
607 
608 	if (result)
609 		goto end;
610 
611 	if (!acpi_battery_present(battery)) {
612 		seq_printf(seq, "present:                 no\n");
613 		goto end;
614 	}
615 	seq_printf(seq, "alarm:                   ");
616 	if (!battery->alarm)
617 		seq_printf(seq, "unsupported\n");
618 	else
619 		seq_printf(seq, "%u %sh\n", battery->alarm,
620 				acpi_battery_units(battery));
621       end:
622 	if (result)
623 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
624 	return result;
625 }
626 
627 static ssize_t acpi_battery_write_alarm(struct file *file,
628 					const char __user * buffer,
629 					size_t count, loff_t * ppos)
630 {
631 	int result = 0;
632 	char alarm_string[12] = { '\0' };
633 	struct seq_file *m = file->private_data;
634 	struct acpi_battery *battery = m->private;
635 
636 	if (!battery || (count > sizeof(alarm_string) - 1))
637 		return -EINVAL;
638 	if (!acpi_battery_present(battery)) {
639 		result = -ENODEV;
640 		goto end;
641 	}
642 	if (copy_from_user(alarm_string, buffer, count)) {
643 		result = -EFAULT;
644 		goto end;
645 	}
646 	alarm_string[count] = '\0';
647 	battery->alarm = simple_strtol(alarm_string, NULL, 0);
648 	result = acpi_battery_set_alarm(battery);
649       end:
650 	if (!result)
651 		return count;
652 	return result;
653 }
654 
655 typedef int(*print_func)(struct seq_file *seq, int result);
656 
657 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
658 	acpi_battery_print_info,
659 	acpi_battery_print_state,
660 	acpi_battery_print_alarm,
661 };
662 
663 static int acpi_battery_read(int fid, struct seq_file *seq)
664 {
665 	struct acpi_battery *battery = seq->private;
666 	int result = acpi_battery_update(battery);
667 	return acpi_print_funcs[fid](seq, result);
668 }
669 
670 #define DECLARE_FILE_FUNCTIONS(_name) \
671 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
672 { \
673 	return acpi_battery_read(_name##_tag, seq); \
674 } \
675 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
676 { \
677 	return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
678 }
679 
680 DECLARE_FILE_FUNCTIONS(info);
681 DECLARE_FILE_FUNCTIONS(state);
682 DECLARE_FILE_FUNCTIONS(alarm);
683 
684 #undef DECLARE_FILE_FUNCTIONS
685 
686 #define FILE_DESCRIPTION_RO(_name) \
687 	{ \
688 	.name = __stringify(_name), \
689 	.mode = S_IRUGO, \
690 	.ops = { \
691 		.open = acpi_battery_##_name##_open_fs, \
692 		.read = seq_read, \
693 		.llseek = seq_lseek, \
694 		.release = single_release, \
695 		.owner = THIS_MODULE, \
696 		}, \
697 	}
698 
699 #define FILE_DESCRIPTION_RW(_name) \
700 	{ \
701 	.name = __stringify(_name), \
702 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
703 	.ops = { \
704 		.open = acpi_battery_##_name##_open_fs, \
705 		.read = seq_read, \
706 		.llseek = seq_lseek, \
707 		.write = acpi_battery_write_##_name, \
708 		.release = single_release, \
709 		.owner = THIS_MODULE, \
710 		}, \
711 	}
712 
713 static struct battery_file {
714 	struct file_operations ops;
715 	mode_t mode;
716 	char *name;
717 } acpi_battery_file[] = {
718 	FILE_DESCRIPTION_RO(info),
719 	FILE_DESCRIPTION_RO(state),
720 	FILE_DESCRIPTION_RW(alarm),
721 };
722 
723 #undef FILE_DESCRIPTION_RO
724 #undef FILE_DESCRIPTION_RW
725 
726 static int acpi_battery_add_fs(struct acpi_device *device)
727 {
728 	struct proc_dir_entry *entry = NULL;
729 	int i;
730 
731 	if (!acpi_device_dir(device)) {
732 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
733 						     acpi_battery_dir);
734 		if (!acpi_device_dir(device))
735 			return -ENODEV;
736 		acpi_device_dir(device)->owner = THIS_MODULE;
737 	}
738 
739 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
740 		entry = create_proc_entry(acpi_battery_file[i].name,
741 				  acpi_battery_file[i].mode, acpi_device_dir(device));
742 		if (!entry)
743 			return -ENODEV;
744 		else {
745 			entry->proc_fops = &acpi_battery_file[i].ops;
746 			entry->data = acpi_driver_data(device);
747 			entry->owner = THIS_MODULE;
748 		}
749 	}
750 	return 0;
751 }
752 
753 static void acpi_battery_remove_fs(struct acpi_device *device)
754 {
755 	int i;
756 	if (!acpi_device_dir(device))
757 		return;
758 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
759 		remove_proc_entry(acpi_battery_file[i].name,
760 				  acpi_device_dir(device));
761 
762 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
763 	acpi_device_dir(device) = NULL;
764 }
765 
766 #endif
767 
768 /* --------------------------------------------------------------------------
769                                  Driver Interface
770    -------------------------------------------------------------------------- */
771 
772 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
773 {
774 	struct acpi_battery *battery = data;
775 	struct acpi_device *device;
776 	if (!battery)
777 		return;
778 	device = battery->device;
779 	acpi_battery_update(battery);
780 	acpi_bus_generate_proc_event(device, event,
781 				     acpi_battery_present(battery));
782 	acpi_bus_generate_netlink_event(device->pnp.device_class,
783 					device->dev.bus_id, event,
784 					acpi_battery_present(battery));
785 #ifdef CONFIG_ACPI_SYSFS_POWER
786 	/* acpi_batter_update could remove power_supply object */
787 	if (battery->bat.dev)
788 		kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
789 #endif
790 }
791 
792 static int acpi_battery_add(struct acpi_device *device)
793 {
794 	int result = 0;
795 	acpi_status status = 0;
796 	struct acpi_battery *battery = NULL;
797 	if (!device)
798 		return -EINVAL;
799 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
800 	if (!battery)
801 		return -ENOMEM;
802 	battery->device = device;
803 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
804 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
805 	acpi_driver_data(device) = battery;
806 	mutex_init(&battery->lock);
807 	acpi_battery_update(battery);
808 #ifdef CONFIG_ACPI_PROCFS_POWER
809 	result = acpi_battery_add_fs(device);
810 	if (result)
811 		goto end;
812 #endif
813 	status = acpi_install_notify_handler(device->handle,
814 					     ACPI_ALL_NOTIFY,
815 					     acpi_battery_notify, battery);
816 	if (ACPI_FAILURE(status)) {
817 		ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
818 		result = -ENODEV;
819 		goto end;
820 	}
821 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
822 	       ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
823 	       device->status.battery_present ? "present" : "absent");
824       end:
825 	if (result) {
826 #ifdef CONFIG_ACPI_PROCFS_POWER
827 		acpi_battery_remove_fs(device);
828 #endif
829 		kfree(battery);
830 	}
831 	return result;
832 }
833 
834 static int acpi_battery_remove(struct acpi_device *device, int type)
835 {
836 	acpi_status status = 0;
837 	struct acpi_battery *battery = NULL;
838 
839 	if (!device || !acpi_driver_data(device))
840 		return -EINVAL;
841 	battery = acpi_driver_data(device);
842 	status = acpi_remove_notify_handler(device->handle,
843 					    ACPI_ALL_NOTIFY,
844 					    acpi_battery_notify);
845 #ifdef CONFIG_ACPI_PROCFS_POWER
846 	acpi_battery_remove_fs(device);
847 #endif
848 #ifdef CONFIG_ACPI_SYSFS_POWER
849 	sysfs_remove_battery(battery);
850 #endif
851 	mutex_destroy(&battery->lock);
852 	kfree(battery);
853 	return 0;
854 }
855 
856 /* this is needed to learn about changes made in suspended state */
857 static int acpi_battery_resume(struct acpi_device *device)
858 {
859 	struct acpi_battery *battery;
860 	if (!device)
861 		return -EINVAL;
862 	battery = acpi_driver_data(device);
863 	battery->update_time = 0;
864 	acpi_battery_update(battery);
865 	return 0;
866 }
867 
868 static struct acpi_driver acpi_battery_driver = {
869 	.name = "battery",
870 	.class = ACPI_BATTERY_CLASS,
871 	.ids = battery_device_ids,
872 	.ops = {
873 		.add = acpi_battery_add,
874 		.resume = acpi_battery_resume,
875 		.remove = acpi_battery_remove,
876 		},
877 };
878 
879 static int __init acpi_battery_init(void)
880 {
881 	if (acpi_disabled)
882 		return -ENODEV;
883 #ifdef CONFIG_ACPI_PROCFS_POWER
884 	acpi_battery_dir = acpi_lock_battery_dir();
885 	if (!acpi_battery_dir)
886 		return -ENODEV;
887 #endif
888 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
889 #ifdef CONFIG_ACPI_PROCFS_POWER
890 		acpi_unlock_battery_dir(acpi_battery_dir);
891 #endif
892 		return -ENODEV;
893 	}
894 	return 0;
895 }
896 
897 static void __exit acpi_battery_exit(void)
898 {
899 	acpi_bus_unregister_driver(&acpi_battery_driver);
900 #ifdef CONFIG_ACPI_PROCFS_POWER
901 	acpi_unlock_battery_dir(acpi_battery_dir);
902 #endif
903 }
904 
905 module_init(acpi_battery_init);
906 module_exit(acpi_battery_exit);
907