xref: /openbmc/linux/drivers/acpi/battery.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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
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 #include <linux/power_supply.h>
44 
45 #define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
46 
47 #define ACPI_BATTERY_COMPONENT		0x00040000
48 #define ACPI_BATTERY_CLASS		"battery"
49 #define ACPI_BATTERY_DEVICE_NAME	"Battery"
50 #define ACPI_BATTERY_NOTIFY_STATUS	0x80
51 #define ACPI_BATTERY_NOTIFY_INFO	0x81
52 
53 #define _COMPONENT		ACPI_BATTERY_COMPONENT
54 
55 ACPI_MODULE_NAME("battery");
56 
57 MODULE_AUTHOR("Paul Diefenbaugh");
58 MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
59 MODULE_DESCRIPTION("ACPI Battery Driver");
60 MODULE_LICENSE("GPL");
61 
62 static unsigned int cache_time = 1000;
63 module_param(cache_time, uint, 0644);
64 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
65 
66 #ifdef CONFIG_ACPI_PROCFS
67 extern struct proc_dir_entry *acpi_lock_battery_dir(void);
68 extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
69 
70 enum acpi_battery_files {
71 	info_tag = 0,
72 	state_tag,
73 	alarm_tag,
74 	ACPI_BATTERY_NUMFILES,
75 };
76 
77 #endif
78 
79 static const struct acpi_device_id battery_device_ids[] = {
80 	{"PNP0C0A", 0},
81 	{"", 0},
82 };
83 
84 MODULE_DEVICE_TABLE(acpi, battery_device_ids);
85 
86 
87 struct acpi_battery {
88 	struct mutex lock;
89 	struct power_supply bat;
90 	struct acpi_device *device;
91 	unsigned long update_time;
92 	int current_now;
93 	int capacity_now;
94 	int voltage_now;
95 	int design_capacity;
96 	int full_charge_capacity;
97 	int technology;
98 	int design_voltage;
99 	int design_capacity_warning;
100 	int design_capacity_low;
101 	int capacity_granularity_1;
102 	int capacity_granularity_2;
103 	int alarm;
104 	char model_number[32];
105 	char serial_number[32];
106 	char type[32];
107 	char oem_info[32];
108 	int state;
109 	int power_unit;
110 	u8 alarm_present;
111 };
112 
113 #define to_acpi_battery(x) container_of(x, struct acpi_battery, bat);
114 
115 inline int acpi_battery_present(struct acpi_battery *battery)
116 {
117 	return battery->device->status.battery_present;
118 }
119 
120 static int acpi_battery_technology(struct acpi_battery *battery)
121 {
122 	if (!strcasecmp("NiCd", battery->type))
123 		return POWER_SUPPLY_TECHNOLOGY_NiCd;
124 	if (!strcasecmp("NiMH", battery->type))
125 		return POWER_SUPPLY_TECHNOLOGY_NiMH;
126 	if (!strcasecmp("LION", battery->type))
127 		return POWER_SUPPLY_TECHNOLOGY_LION;
128 	if (!strcasecmp("LiP", battery->type))
129 		return POWER_SUPPLY_TECHNOLOGY_LIPO;
130 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
131 }
132 
133 static int acpi_battery_get_property(struct power_supply *psy,
134 				     enum power_supply_property psp,
135 				     union power_supply_propval *val)
136 {
137 	struct acpi_battery *battery = to_acpi_battery(psy);
138 
139 	if ((!acpi_battery_present(battery)) &&
140 	     psp != POWER_SUPPLY_PROP_PRESENT)
141 		return -ENODEV;
142 	switch (psp) {
143 	case POWER_SUPPLY_PROP_STATUS:
144 		if (battery->state & 0x01)
145 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
146 		else if (battery->state & 0x02)
147 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
148 		else if (battery->state == 0)
149 			val->intval = POWER_SUPPLY_STATUS_FULL;
150 		break;
151 	case POWER_SUPPLY_PROP_PRESENT:
152 		val->intval = acpi_battery_present(battery);
153 		break;
154 	case POWER_SUPPLY_PROP_TECHNOLOGY:
155 		val->intval = acpi_battery_technology(battery);
156 		break;
157 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
158 		val->intval = battery->design_voltage * 1000;
159 		break;
160 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
161 		val->intval = battery->voltage_now * 1000;
162 		break;
163 	case POWER_SUPPLY_PROP_CURRENT_NOW:
164 		val->intval = battery->current_now * 1000;
165 		break;
166 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
167 	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
168 		val->intval = battery->design_capacity * 1000;
169 		break;
170 	case POWER_SUPPLY_PROP_CHARGE_FULL:
171 	case POWER_SUPPLY_PROP_ENERGY_FULL:
172 		val->intval = battery->full_charge_capacity * 1000;
173 		break;
174 	case POWER_SUPPLY_PROP_CHARGE_NOW:
175 	case POWER_SUPPLY_PROP_ENERGY_NOW:
176 		val->intval = battery->capacity_now * 1000;
177 		break;
178 	case POWER_SUPPLY_PROP_MODEL_NAME:
179 		val->strval = battery->model_number;
180 		break;
181 	case POWER_SUPPLY_PROP_MANUFACTURER:
182 		val->strval = battery->oem_info;
183 		break;
184 	default:
185 		return -EINVAL;
186 	}
187 	return 0;
188 }
189 
190 static enum power_supply_property charge_battery_props[] = {
191 	POWER_SUPPLY_PROP_STATUS,
192 	POWER_SUPPLY_PROP_PRESENT,
193 	POWER_SUPPLY_PROP_TECHNOLOGY,
194 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
195 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
196 	POWER_SUPPLY_PROP_CURRENT_NOW,
197 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
198 	POWER_SUPPLY_PROP_CHARGE_FULL,
199 	POWER_SUPPLY_PROP_CHARGE_NOW,
200 	POWER_SUPPLY_PROP_MODEL_NAME,
201 	POWER_SUPPLY_PROP_MANUFACTURER,
202 };
203 
204 static enum power_supply_property energy_battery_props[] = {
205 	POWER_SUPPLY_PROP_STATUS,
206 	POWER_SUPPLY_PROP_PRESENT,
207 	POWER_SUPPLY_PROP_TECHNOLOGY,
208 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
209 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
210 	POWER_SUPPLY_PROP_CURRENT_NOW,
211 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
212 	POWER_SUPPLY_PROP_ENERGY_FULL,
213 	POWER_SUPPLY_PROP_ENERGY_NOW,
214 	POWER_SUPPLY_PROP_MODEL_NAME,
215 	POWER_SUPPLY_PROP_MANUFACTURER,
216 };
217 
218 #ifdef CONFIG_ACPI_PROCFS
219 inline char *acpi_battery_units(struct acpi_battery *battery)
220 {
221 	return (battery->power_unit)?"mA":"mW";
222 }
223 #endif
224 
225 /* --------------------------------------------------------------------------
226                                Battery Management
227    -------------------------------------------------------------------------- */
228 struct acpi_offsets {
229 	size_t offset;		/* offset inside struct acpi_sbs_battery */
230 	u8 mode;		/* int or string? */
231 };
232 
233 static struct acpi_offsets state_offsets[] = {
234 	{offsetof(struct acpi_battery, state), 0},
235 	{offsetof(struct acpi_battery, current_now), 0},
236 	{offsetof(struct acpi_battery, capacity_now), 0},
237 	{offsetof(struct acpi_battery, voltage_now), 0},
238 };
239 
240 static struct acpi_offsets info_offsets[] = {
241 	{offsetof(struct acpi_battery, power_unit), 0},
242 	{offsetof(struct acpi_battery, design_capacity), 0},
243 	{offsetof(struct acpi_battery, full_charge_capacity), 0},
244 	{offsetof(struct acpi_battery, technology), 0},
245 	{offsetof(struct acpi_battery, design_voltage), 0},
246 	{offsetof(struct acpi_battery, design_capacity_warning), 0},
247 	{offsetof(struct acpi_battery, design_capacity_low), 0},
248 	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
249 	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
250 	{offsetof(struct acpi_battery, model_number), 1},
251 	{offsetof(struct acpi_battery, serial_number), 1},
252 	{offsetof(struct acpi_battery, type), 1},
253 	{offsetof(struct acpi_battery, oem_info), 1},
254 };
255 
256 static int extract_package(struct acpi_battery *battery,
257 			   union acpi_object *package,
258 			   struct acpi_offsets *offsets, int num)
259 {
260 	int i, *x;
261 	union acpi_object *element;
262 	if (package->type != ACPI_TYPE_PACKAGE)
263 		return -EFAULT;
264 	for (i = 0; i < num; ++i) {
265 		if (package->package.count <= i)
266 			return -EFAULT;
267 		element = &package->package.elements[i];
268 		if (offsets[i].mode) {
269 			if (element->type != ACPI_TYPE_STRING &&
270 			    element->type != ACPI_TYPE_BUFFER)
271 				return -EFAULT;
272 			strncpy((u8 *)battery + offsets[i].offset,
273 				element->string.pointer, 32);
274 		} else {
275 			if (element->type != ACPI_TYPE_INTEGER)
276 				return -EFAULT;
277 			x = (int *)((u8 *)battery + offsets[i].offset);
278 			*x = element->integer.value;
279 		}
280 	}
281 	return 0;
282 }
283 
284 static int acpi_battery_get_status(struct acpi_battery *battery)
285 {
286 	if (acpi_bus_get_status(battery->device)) {
287 		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
288 		return -ENODEV;
289 	}
290 	return 0;
291 }
292 
293 static int acpi_battery_get_info(struct acpi_battery *battery)
294 {
295 	int result = -EFAULT;
296 	acpi_status status = 0;
297 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
298 
299 	if (!acpi_battery_present(battery))
300 		return 0;
301 	mutex_lock(&battery->lock);
302 	status = acpi_evaluate_object(battery->device->handle, "_BIF",
303 				      NULL, &buffer);
304 	mutex_unlock(&battery->lock);
305 
306 	if (ACPI_FAILURE(status)) {
307 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
308 		return -ENODEV;
309 	}
310 
311 	result = extract_package(battery, buffer.pointer,
312 				 info_offsets, ARRAY_SIZE(info_offsets));
313 	kfree(buffer.pointer);
314 	return result;
315 }
316 
317 static int acpi_battery_get_state(struct acpi_battery *battery)
318 {
319 	int result = 0;
320 	acpi_status status = 0;
321 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
322 
323 	if (!acpi_battery_present(battery))
324 		return 0;
325 
326 	if (battery->update_time &&
327 	    time_before(jiffies, battery->update_time +
328 			msecs_to_jiffies(cache_time)))
329 		return 0;
330 
331 	mutex_lock(&battery->lock);
332 	status = acpi_evaluate_object(battery->device->handle, "_BST",
333 				      NULL, &buffer);
334 	mutex_unlock(&battery->lock);
335 
336 	if (ACPI_FAILURE(status)) {
337 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
338 		return -ENODEV;
339 	}
340 
341 	result = extract_package(battery, buffer.pointer,
342 				 state_offsets, ARRAY_SIZE(state_offsets));
343 	battery->update_time = jiffies;
344 	kfree(buffer.pointer);
345 	return result;
346 }
347 
348 static int acpi_battery_set_alarm(struct acpi_battery *battery)
349 {
350 	acpi_status status = 0;
351 	union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
352 	struct acpi_object_list arg_list = { 1, &arg0 };
353 
354 	if (!acpi_battery_present(battery)|| !battery->alarm_present)
355 		return -ENODEV;
356 
357 	arg0.integer.value = battery->alarm;
358 
359 	mutex_lock(&battery->lock);
360 	status = acpi_evaluate_object(battery->device->handle, "_BTP",
361 				 &arg_list, NULL);
362 	mutex_unlock(&battery->lock);
363 
364 	if (ACPI_FAILURE(status))
365 		return -ENODEV;
366 
367 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
368 	return 0;
369 }
370 
371 static int acpi_battery_init_alarm(struct acpi_battery *battery)
372 {
373 	acpi_status status = AE_OK;
374 	acpi_handle handle = NULL;
375 
376 	/* See if alarms are supported, and if so, set default */
377 	status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
378 	if (ACPI_FAILURE(status)) {
379 		battery->alarm_present = 0;
380 		return 0;
381 	}
382 	battery->alarm_present = 1;
383 	if (!battery->alarm)
384 		battery->alarm = battery->design_capacity_warning;
385 	return acpi_battery_set_alarm(battery);
386 }
387 
388 static int acpi_battery_update(struct acpi_battery *battery)
389 {
390 	int saved_present = acpi_battery_present(battery);
391 	int result = acpi_battery_get_status(battery);
392 	if (result || !acpi_battery_present(battery))
393 		return result;
394 	if (saved_present != acpi_battery_present(battery) ||
395 	    !battery->update_time) {
396 		battery->update_time = 0;
397 		result = acpi_battery_get_info(battery);
398 		if (result)
399 			return result;
400 		if (battery->power_unit) {
401 			battery->bat.properties = charge_battery_props;
402 			battery->bat.num_properties =
403 				ARRAY_SIZE(charge_battery_props);
404 		} else {
405 			battery->bat.properties = energy_battery_props;
406 			battery->bat.num_properties =
407 				ARRAY_SIZE(energy_battery_props);
408 		}
409 		acpi_battery_init_alarm(battery);
410 	}
411 	return acpi_battery_get_state(battery);
412 }
413 
414 /* --------------------------------------------------------------------------
415                               FS Interface (/proc)
416    -------------------------------------------------------------------------- */
417 
418 #ifdef CONFIG_ACPI_PROCFS
419 static struct proc_dir_entry *acpi_battery_dir;
420 
421 static int acpi_battery_print_info(struct seq_file *seq, int result)
422 {
423 	struct acpi_battery *battery = seq->private;
424 
425 	if (result)
426 		goto end;
427 
428 	seq_printf(seq, "present:                 %s\n",
429 		   acpi_battery_present(battery)?"yes":"no");
430 	if (!acpi_battery_present(battery))
431 		goto end;
432 	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
433 		seq_printf(seq, "design capacity:         unknown\n");
434 	else
435 		seq_printf(seq, "design capacity:         %d %sh\n",
436 			   battery->design_capacity,
437 			   acpi_battery_units(battery));
438 
439 	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
440 		seq_printf(seq, "last full capacity:      unknown\n");
441 	else
442 		seq_printf(seq, "last full capacity:      %d %sh\n",
443 			   battery->full_charge_capacity,
444 			   acpi_battery_units(battery));
445 
446 	seq_printf(seq, "battery technology:      %srechargeable\n",
447 		   (!battery->technology)?"non-":"");
448 
449 	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
450 		seq_printf(seq, "design voltage:          unknown\n");
451 	else
452 		seq_printf(seq, "design voltage:          %d mV\n",
453 			   battery->design_voltage);
454 	seq_printf(seq, "design capacity warning: %d %sh\n",
455 		   battery->design_capacity_warning,
456 		   acpi_battery_units(battery));
457 	seq_printf(seq, "design capacity low:     %d %sh\n",
458 		   battery->design_capacity_low,
459 		   acpi_battery_units(battery));
460 	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
461 		   battery->capacity_granularity_1,
462 		   acpi_battery_units(battery));
463 	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
464 		   battery->capacity_granularity_2,
465 		   acpi_battery_units(battery));
466 	seq_printf(seq, "model number:            %s\n", battery->model_number);
467 	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
468 	seq_printf(seq, "battery type:            %s\n", battery->type);
469 	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
470       end:
471 	if (result)
472 		seq_printf(seq, "ERROR: Unable to read battery info\n");
473 	return result;
474 }
475 
476 static int acpi_battery_print_state(struct seq_file *seq, int result)
477 {
478 	struct acpi_battery *battery = seq->private;
479 
480 	if (result)
481 		goto end;
482 
483 	seq_printf(seq, "present:                 %s\n",
484 		   acpi_battery_present(battery)?"yes":"no");
485 	if (!acpi_battery_present(battery))
486 		goto end;
487 
488 	seq_printf(seq, "capacity state:          %s\n",
489 			(battery->state & 0x04)?"critical":"ok");
490 	if ((battery->state & 0x01) && (battery->state & 0x02))
491 		seq_printf(seq,
492 			   "charging state:          charging/discharging\n");
493 	else if (battery->state & 0x01)
494 		seq_printf(seq, "charging state:          discharging\n");
495 	else if (battery->state & 0x02)
496 		seq_printf(seq, "charging state:          charging\n");
497 	else
498 		seq_printf(seq, "charging state:          charged\n");
499 
500 	if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
501 		seq_printf(seq, "present rate:            unknown\n");
502 	else
503 		seq_printf(seq, "present rate:            %d %s\n",
504 			   battery->current_now, acpi_battery_units(battery));
505 
506 	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
507 		seq_printf(seq, "remaining capacity:      unknown\n");
508 	else
509 		seq_printf(seq, "remaining capacity:      %d %sh\n",
510 			   battery->capacity_now, acpi_battery_units(battery));
511 	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
512 		seq_printf(seq, "present voltage:         unknown\n");
513 	else
514 		seq_printf(seq, "present voltage:         %d mV\n",
515 			   battery->voltage_now);
516       end:
517 	if (result)
518 		seq_printf(seq, "ERROR: Unable to read battery state\n");
519 
520 	return result;
521 }
522 
523 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
524 {
525 	struct acpi_battery *battery = seq->private;
526 
527 	if (result)
528 		goto end;
529 
530 	if (!acpi_battery_present(battery)) {
531 		seq_printf(seq, "present:                 no\n");
532 		goto end;
533 	}
534 	seq_printf(seq, "alarm:                   ");
535 	if (!battery->alarm)
536 		seq_printf(seq, "unsupported\n");
537 	else
538 		seq_printf(seq, "%u %sh\n", battery->alarm,
539 				acpi_battery_units(battery));
540       end:
541 	if (result)
542 		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
543 	return result;
544 }
545 
546 static ssize_t acpi_battery_write_alarm(struct file *file,
547 					const char __user * buffer,
548 					size_t count, loff_t * ppos)
549 {
550 	int result = 0;
551 	char alarm_string[12] = { '\0' };
552 	struct seq_file *m = file->private_data;
553 	struct acpi_battery *battery = m->private;
554 
555 	if (!battery || (count > sizeof(alarm_string) - 1))
556 		return -EINVAL;
557 	if (result) {
558 		result = -ENODEV;
559 		goto end;
560 	}
561 	if (!acpi_battery_present(battery)) {
562 		result = -ENODEV;
563 		goto end;
564 	}
565 	if (copy_from_user(alarm_string, buffer, count)) {
566 		result = -EFAULT;
567 		goto end;
568 	}
569 	alarm_string[count] = '\0';
570 	battery->alarm = simple_strtol(alarm_string, NULL, 0);
571 	result = acpi_battery_set_alarm(battery);
572       end:
573 	if (!result)
574 		return count;
575 	return result;
576 }
577 
578 typedef int(*print_func)(struct seq_file *seq, int result);
579 
580 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
581 	acpi_battery_print_info,
582 	acpi_battery_print_state,
583 	acpi_battery_print_alarm,
584 };
585 
586 static int acpi_battery_read(int fid, struct seq_file *seq)
587 {
588 	struct acpi_battery *battery = seq->private;
589 	int result = acpi_battery_update(battery);
590 	return acpi_print_funcs[fid](seq, result);
591 }
592 
593 #define DECLARE_FILE_FUNCTIONS(_name) \
594 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
595 { \
596 	return acpi_battery_read(_name##_tag, seq); \
597 } \
598 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
599 { \
600 	return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
601 }
602 
603 DECLARE_FILE_FUNCTIONS(info);
604 DECLARE_FILE_FUNCTIONS(state);
605 DECLARE_FILE_FUNCTIONS(alarm);
606 
607 #undef DECLARE_FILE_FUNCTIONS
608 
609 #define FILE_DESCRIPTION_RO(_name) \
610 	{ \
611 	.name = __stringify(_name), \
612 	.mode = S_IRUGO, \
613 	.ops = { \
614 		.open = acpi_battery_##_name##_open_fs, \
615 		.read = seq_read, \
616 		.llseek = seq_lseek, \
617 		.release = single_release, \
618 		.owner = THIS_MODULE, \
619 		}, \
620 	}
621 
622 #define FILE_DESCRIPTION_RW(_name) \
623 	{ \
624 	.name = __stringify(_name), \
625 	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
626 	.ops = { \
627 		.open = acpi_battery_##_name##_open_fs, \
628 		.read = seq_read, \
629 		.llseek = seq_lseek, \
630 		.write = acpi_battery_write_##_name, \
631 		.release = single_release, \
632 		.owner = THIS_MODULE, \
633 		}, \
634 	}
635 
636 static struct battery_file {
637 	struct file_operations ops;
638 	mode_t mode;
639 	char *name;
640 } acpi_battery_file[] = {
641 	FILE_DESCRIPTION_RO(info),
642 	FILE_DESCRIPTION_RO(state),
643 	FILE_DESCRIPTION_RW(alarm),
644 };
645 
646 #undef FILE_DESCRIPTION_RO
647 #undef FILE_DESCRIPTION_RW
648 
649 static int acpi_battery_add_fs(struct acpi_device *device)
650 {
651 	struct proc_dir_entry *entry = NULL;
652 	int i;
653 
654 	if (!acpi_device_dir(device)) {
655 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
656 						     acpi_battery_dir);
657 		if (!acpi_device_dir(device))
658 			return -ENODEV;
659 		acpi_device_dir(device)->owner = THIS_MODULE;
660 	}
661 
662 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
663 		entry = create_proc_entry(acpi_battery_file[i].name,
664 				  acpi_battery_file[i].mode, acpi_device_dir(device));
665 		if (!entry)
666 			return -ENODEV;
667 		else {
668 			entry->proc_fops = &acpi_battery_file[i].ops;
669 			entry->data = acpi_driver_data(device);
670 			entry->owner = THIS_MODULE;
671 		}
672 	}
673 	return 0;
674 }
675 
676 static void acpi_battery_remove_fs(struct acpi_device *device)
677 {
678 	int i;
679 	if (!acpi_device_dir(device))
680 		return;
681 	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
682 		remove_proc_entry(acpi_battery_file[i].name,
683 				  acpi_device_dir(device));
684 
685 	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
686 	acpi_device_dir(device) = NULL;
687 }
688 
689 #endif
690 
691 static ssize_t acpi_battery_alarm_show(struct device *dev,
692 					struct device_attribute *attr,
693 					char *buf)
694 {
695 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
696 	return sprintf(buf, "%d\n", battery->alarm * 1000);
697 }
698 
699 static ssize_t acpi_battery_alarm_store(struct device *dev,
700 					struct device_attribute *attr,
701 					const char *buf, size_t count)
702 {
703 	unsigned long x;
704 	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
705 	if (sscanf(buf, "%ld\n", &x) == 1)
706 		battery->alarm = x/1000;
707 	if (acpi_battery_present(battery))
708 		acpi_battery_set_alarm(battery);
709 	return count;
710 }
711 
712 static struct device_attribute alarm_attr = {
713 	.attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE},
714 	.show = acpi_battery_alarm_show,
715 	.store = acpi_battery_alarm_store,
716 };
717 
718 /* --------------------------------------------------------------------------
719                                  Driver Interface
720    -------------------------------------------------------------------------- */
721 
722 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
723 {
724 	struct acpi_battery *battery = data;
725 	struct acpi_device *device;
726 	if (!battery)
727 		return;
728 	device = battery->device;
729 	acpi_battery_update(battery);
730 	acpi_bus_generate_proc_event(device, event,
731 				     acpi_battery_present(battery));
732 	acpi_bus_generate_netlink_event(device->pnp.device_class,
733 					device->dev.bus_id, event,
734 					acpi_battery_present(battery));
735 	kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
736 }
737 
738 static int acpi_battery_add(struct acpi_device *device)
739 {
740 	int result = 0;
741 	acpi_status status = 0;
742 	struct acpi_battery *battery = NULL;
743 	if (!device)
744 		return -EINVAL;
745 	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
746 	if (!battery)
747 		return -ENOMEM;
748 	battery->device = device;
749 	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
750 	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
751 	acpi_driver_data(device) = battery;
752 	mutex_init(&battery->lock);
753 	acpi_battery_update(battery);
754 #ifdef CONFIG_ACPI_PROCFS
755 	result = acpi_battery_add_fs(device);
756 	if (result)
757 		goto end;
758 #endif
759 	battery->bat.name = acpi_device_bid(device);
760 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
761 	battery->bat.get_property = acpi_battery_get_property;
762 	result = power_supply_register(&battery->device->dev, &battery->bat);
763 	result = device_create_file(battery->bat.dev, &alarm_attr);
764 	status = acpi_install_notify_handler(device->handle,
765 					     ACPI_ALL_NOTIFY,
766 					     acpi_battery_notify, battery);
767 	if (ACPI_FAILURE(status)) {
768 		ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
769 		result = -ENODEV;
770 		goto end;
771 	}
772 	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
773 	       ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
774 	       device->status.battery_present ? "present" : "absent");
775       end:
776 	if (result) {
777 #ifdef CONFIG_ACPI_PROCFS
778 		acpi_battery_remove_fs(device);
779 #endif
780 		kfree(battery);
781 	}
782 	return result;
783 }
784 
785 static int acpi_battery_remove(struct acpi_device *device, int type)
786 {
787 	acpi_status status = 0;
788 	struct acpi_battery *battery = NULL;
789 
790 	if (!device || !acpi_driver_data(device))
791 		return -EINVAL;
792 	battery = acpi_driver_data(device);
793 	status = acpi_remove_notify_handler(device->handle,
794 					    ACPI_ALL_NOTIFY,
795 					    acpi_battery_notify);
796 #ifdef CONFIG_ACPI_PROCFS
797 	acpi_battery_remove_fs(device);
798 #endif
799 	if (battery->bat.dev) {
800 		device_remove_file(battery->bat.dev, &alarm_attr);
801 		power_supply_unregister(&battery->bat);
802 	}
803 	mutex_destroy(&battery->lock);
804 	kfree(battery);
805 	return 0;
806 }
807 
808 /* this is needed to learn about changes made in suspended state */
809 static int acpi_battery_resume(struct acpi_device *device)
810 {
811 	struct acpi_battery *battery;
812 	if (!device)
813 		return -EINVAL;
814 	battery = acpi_driver_data(device);
815 	battery->update_time = 0;
816 	return 0;
817 }
818 
819 static struct acpi_driver acpi_battery_driver = {
820 	.name = "battery",
821 	.class = ACPI_BATTERY_CLASS,
822 	.ids = battery_device_ids,
823 	.ops = {
824 		.add = acpi_battery_add,
825 		.resume = acpi_battery_resume,
826 		.remove = acpi_battery_remove,
827 		},
828 };
829 
830 static int __init acpi_battery_init(void)
831 {
832 	if (acpi_disabled)
833 		return -ENODEV;
834 #ifdef CONFIG_ACPI_PROCFS
835 	acpi_battery_dir = acpi_lock_battery_dir();
836 	if (!acpi_battery_dir)
837 		return -ENODEV;
838 #endif
839 	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
840 #ifdef CONFIG_ACPI_PROCFS
841 		acpi_unlock_battery_dir(acpi_battery_dir);
842 #endif
843 		return -ENODEV;
844 	}
845 	return 0;
846 }
847 
848 static void __exit acpi_battery_exit(void)
849 {
850 	acpi_bus_unregister_driver(&acpi_battery_driver);
851 #ifdef CONFIG_ACPI_PROCFS
852 	acpi_unlock_battery_dir(acpi_battery_dir);
853 #endif
854 }
855 
856 module_init(acpi_battery_init);
857 module_exit(acpi_battery_exit);
858