ACPI: Always return valid 'status' from acpi_battery_get_property()
[linux-3.10.git] / drivers / acpi / battery.c
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("LI-ION", battery->type))
129                 return POWER_SUPPLY_TECHNOLOGY_LION;
130         if (!strcasecmp("LiP", battery->type))
131                 return POWER_SUPPLY_TECHNOLOGY_LIPO;
132         return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
133 }
134
135 static int acpi_battery_update(struct acpi_battery *battery);
136
137 static int acpi_battery_get_property(struct power_supply *psy,
138                                      enum power_supply_property psp,
139                                      union power_supply_propval *val)
140 {
141         struct acpi_battery *battery = to_acpi_battery(psy);
142
143         if ((!acpi_battery_present(battery)) &&
144              psp != POWER_SUPPLY_PROP_PRESENT)
145                 return -ENODEV;
146         acpi_battery_update(battery);
147         switch (psp) {
148         case POWER_SUPPLY_PROP_STATUS:
149                 if (battery->state & 0x01)
150                         val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
151                 else if (battery->state & 0x02)
152                         val->intval = POWER_SUPPLY_STATUS_CHARGING;
153                 else if (battery->state == 0)
154                         val->intval = POWER_SUPPLY_STATUS_FULL;
155                 else
156                         val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
157                 break;
158         case POWER_SUPPLY_PROP_PRESENT:
159                 val->intval = acpi_battery_present(battery);
160                 break;
161         case POWER_SUPPLY_PROP_TECHNOLOGY:
162                 val->intval = acpi_battery_technology(battery);
163                 break;
164         case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
165                 val->intval = battery->design_voltage * 1000;
166                 break;
167         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
168                 val->intval = battery->voltage_now * 1000;
169                 break;
170         case POWER_SUPPLY_PROP_CURRENT_NOW:
171                 val->intval = battery->current_now * 1000;
172                 break;
173         case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
174         case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
175                 val->intval = battery->design_capacity * 1000;
176                 break;
177         case POWER_SUPPLY_PROP_CHARGE_FULL:
178         case POWER_SUPPLY_PROP_ENERGY_FULL:
179                 val->intval = battery->full_charge_capacity * 1000;
180                 break;
181         case POWER_SUPPLY_PROP_CHARGE_NOW:
182         case POWER_SUPPLY_PROP_ENERGY_NOW:
183                 val->intval = battery->capacity_now * 1000;
184                 break;
185         case POWER_SUPPLY_PROP_MODEL_NAME:
186                 val->strval = battery->model_number;
187                 break;
188         case POWER_SUPPLY_PROP_MANUFACTURER:
189                 val->strval = battery->oem_info;
190                 break;
191         default:
192                 return -EINVAL;
193         }
194         return 0;
195 }
196
197 static enum power_supply_property charge_battery_props[] = {
198         POWER_SUPPLY_PROP_STATUS,
199         POWER_SUPPLY_PROP_PRESENT,
200         POWER_SUPPLY_PROP_TECHNOLOGY,
201         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
202         POWER_SUPPLY_PROP_VOLTAGE_NOW,
203         POWER_SUPPLY_PROP_CURRENT_NOW,
204         POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
205         POWER_SUPPLY_PROP_CHARGE_FULL,
206         POWER_SUPPLY_PROP_CHARGE_NOW,
207         POWER_SUPPLY_PROP_MODEL_NAME,
208         POWER_SUPPLY_PROP_MANUFACTURER,
209 };
210
211 static enum power_supply_property energy_battery_props[] = {
212         POWER_SUPPLY_PROP_STATUS,
213         POWER_SUPPLY_PROP_PRESENT,
214         POWER_SUPPLY_PROP_TECHNOLOGY,
215         POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
216         POWER_SUPPLY_PROP_VOLTAGE_NOW,
217         POWER_SUPPLY_PROP_CURRENT_NOW,
218         POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
219         POWER_SUPPLY_PROP_ENERGY_FULL,
220         POWER_SUPPLY_PROP_ENERGY_NOW,
221         POWER_SUPPLY_PROP_MODEL_NAME,
222         POWER_SUPPLY_PROP_MANUFACTURER,
223 };
224
225 #ifdef CONFIG_ACPI_PROCFS
226 inline char *acpi_battery_units(struct acpi_battery *battery)
227 {
228         return (battery->power_unit)?"mA":"mW";
229 }
230 #endif
231
232 /* --------------------------------------------------------------------------
233                                Battery Management
234    -------------------------------------------------------------------------- */
235 struct acpi_offsets {
236         size_t offset;          /* offset inside struct acpi_sbs_battery */
237         u8 mode;                /* int or string? */
238 };
239
240 static struct acpi_offsets state_offsets[] = {
241         {offsetof(struct acpi_battery, state), 0},
242         {offsetof(struct acpi_battery, current_now), 0},
243         {offsetof(struct acpi_battery, capacity_now), 0},
244         {offsetof(struct acpi_battery, voltage_now), 0},
245 };
246
247 static struct acpi_offsets info_offsets[] = {
248         {offsetof(struct acpi_battery, power_unit), 0},
249         {offsetof(struct acpi_battery, design_capacity), 0},
250         {offsetof(struct acpi_battery, full_charge_capacity), 0},
251         {offsetof(struct acpi_battery, technology), 0},
252         {offsetof(struct acpi_battery, design_voltage), 0},
253         {offsetof(struct acpi_battery, design_capacity_warning), 0},
254         {offsetof(struct acpi_battery, design_capacity_low), 0},
255         {offsetof(struct acpi_battery, capacity_granularity_1), 0},
256         {offsetof(struct acpi_battery, capacity_granularity_2), 0},
257         {offsetof(struct acpi_battery, model_number), 1},
258         {offsetof(struct acpi_battery, serial_number), 1},
259         {offsetof(struct acpi_battery, type), 1},
260         {offsetof(struct acpi_battery, oem_info), 1},
261 };
262
263 static int extract_package(struct acpi_battery *battery,
264                            union acpi_object *package,
265                            struct acpi_offsets *offsets, int num)
266 {
267         int i;
268         union acpi_object *element;
269         if (package->type != ACPI_TYPE_PACKAGE)
270                 return -EFAULT;
271         for (i = 0; i < num; ++i) {
272                 if (package->package.count <= i)
273                         return -EFAULT;
274                 element = &package->package.elements[i];
275                 if (offsets[i].mode) {
276                         u8 *ptr = (u8 *)battery + offsets[i].offset;
277                         if (element->type == ACPI_TYPE_STRING ||
278                             element->type == ACPI_TYPE_BUFFER)
279                                 strncpy(ptr, element->string.pointer, 32);
280                         else if (element->type == ACPI_TYPE_INTEGER) {
281                                 strncpy(ptr, (u8 *)&element->integer.value,
282                                         sizeof(acpi_integer));
283                                 ptr[sizeof(acpi_integer)] = 0;
284                         } else return -EFAULT;
285                 } else {
286                         if (element->type == ACPI_TYPE_INTEGER) {
287                                 int *x = (int *)((u8 *)battery +
288                                                 offsets[i].offset);
289                                 *x = element->integer.value;
290                         } else return -EFAULT;
291                 }
292         }
293         return 0;
294 }
295
296 static int acpi_battery_get_status(struct acpi_battery *battery)
297 {
298         if (acpi_bus_get_status(battery->device)) {
299                 ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
300                 return -ENODEV;
301         }
302         return 0;
303 }
304
305 static int acpi_battery_get_info(struct acpi_battery *battery)
306 {
307         int result = -EFAULT;
308         acpi_status status = 0;
309         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
310
311         if (!acpi_battery_present(battery))
312                 return 0;
313         mutex_lock(&battery->lock);
314         status = acpi_evaluate_object(battery->device->handle, "_BIF",
315                                       NULL, &buffer);
316         mutex_unlock(&battery->lock);
317
318         if (ACPI_FAILURE(status)) {
319                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BIF"));
320                 return -ENODEV;
321         }
322
323         result = extract_package(battery, buffer.pointer,
324                                  info_offsets, ARRAY_SIZE(info_offsets));
325         kfree(buffer.pointer);
326         return result;
327 }
328
329 static int acpi_battery_get_state(struct acpi_battery *battery)
330 {
331         int result = 0;
332         acpi_status status = 0;
333         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
334
335         if (!acpi_battery_present(battery))
336                 return 0;
337
338         if (battery->update_time &&
339             time_before(jiffies, battery->update_time +
340                         msecs_to_jiffies(cache_time)))
341                 return 0;
342
343         mutex_lock(&battery->lock);
344         status = acpi_evaluate_object(battery->device->handle, "_BST",
345                                       NULL, &buffer);
346         mutex_unlock(&battery->lock);
347
348         if (ACPI_FAILURE(status)) {
349                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
350                 return -ENODEV;
351         }
352
353         result = extract_package(battery, buffer.pointer,
354                                  state_offsets, ARRAY_SIZE(state_offsets));
355         battery->update_time = jiffies;
356         kfree(buffer.pointer);
357         return result;
358 }
359
360 static int acpi_battery_set_alarm(struct acpi_battery *battery)
361 {
362         acpi_status status = 0;
363         union acpi_object arg0 = { .type = ACPI_TYPE_INTEGER };
364         struct acpi_object_list arg_list = { 1, &arg0 };
365
366         if (!acpi_battery_present(battery)|| !battery->alarm_present)
367                 return -ENODEV;
368
369         arg0.integer.value = battery->alarm;
370
371         mutex_lock(&battery->lock);
372         status = acpi_evaluate_object(battery->device->handle, "_BTP",
373                                  &arg_list, NULL);
374         mutex_unlock(&battery->lock);
375
376         if (ACPI_FAILURE(status))
377                 return -ENODEV;
378
379         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
380         return 0;
381 }
382
383 static int acpi_battery_init_alarm(struct acpi_battery *battery)
384 {
385         acpi_status status = AE_OK;
386         acpi_handle handle = NULL;
387
388         /* See if alarms are supported, and if so, set default */
389         status = acpi_get_handle(battery->device->handle, "_BTP", &handle);
390         if (ACPI_FAILURE(status)) {
391                 battery->alarm_present = 0;
392                 return 0;
393         }
394         battery->alarm_present = 1;
395         if (!battery->alarm)
396                 battery->alarm = battery->design_capacity_warning;
397         return acpi_battery_set_alarm(battery);
398 }
399
400 static ssize_t acpi_battery_alarm_show(struct device *dev,
401                                         struct device_attribute *attr,
402                                         char *buf)
403 {
404         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
405         return sprintf(buf, "%d\n", battery->alarm * 1000);
406 }
407
408 static ssize_t acpi_battery_alarm_store(struct device *dev,
409                                         struct device_attribute *attr,
410                                         const char *buf, size_t count)
411 {
412         unsigned long x;
413         struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
414         if (sscanf(buf, "%ld\n", &x) == 1)
415                 battery->alarm = x/1000;
416         if (acpi_battery_present(battery))
417                 acpi_battery_set_alarm(battery);
418         return count;
419 }
420
421 static struct device_attribute alarm_attr = {
422         .attr = {.name = "alarm", .mode = 0644, .owner = THIS_MODULE},
423         .show = acpi_battery_alarm_show,
424         .store = acpi_battery_alarm_store,
425 };
426
427 static int sysfs_add_battery(struct acpi_battery *battery)
428 {
429         int result;
430
431         battery->update_time = 0;
432         result = acpi_battery_get_info(battery);
433         acpi_battery_init_alarm(battery);
434         if (result)
435                 return result;
436         if (battery->power_unit) {
437                 battery->bat.properties = charge_battery_props;
438                 battery->bat.num_properties =
439                         ARRAY_SIZE(charge_battery_props);
440         } else {
441                 battery->bat.properties = energy_battery_props;
442                 battery->bat.num_properties =
443                         ARRAY_SIZE(energy_battery_props);
444         }
445
446         battery->bat.name = acpi_device_bid(battery->device);
447         battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
448         battery->bat.get_property = acpi_battery_get_property;
449
450         result = power_supply_register(&battery->device->dev, &battery->bat);
451         if (result)
452                 return result;
453         return device_create_file(battery->bat.dev, &alarm_attr);
454 }
455
456 static void sysfs_remove_battery(struct acpi_battery *battery)
457 {
458         if (!battery->bat.dev)
459                 return;
460         device_remove_file(battery->bat.dev, &alarm_attr);
461         power_supply_unregister(&battery->bat);
462 }
463
464 static int acpi_battery_update(struct acpi_battery *battery)
465 {
466         int result = acpi_battery_get_status(battery);
467         if (result)
468                 return result;
469         if (!acpi_battery_present(battery)) {
470                 sysfs_remove_battery(battery);
471                 return 0;
472         }
473         if (!battery->bat.dev)
474                 sysfs_add_battery(battery);
475         return acpi_battery_get_state(battery);
476 }
477
478 /* --------------------------------------------------------------------------
479                               FS Interface (/proc)
480    -------------------------------------------------------------------------- */
481
482 #ifdef CONFIG_ACPI_PROCFS
483 static struct proc_dir_entry *acpi_battery_dir;
484
485 static int acpi_battery_print_info(struct seq_file *seq, int result)
486 {
487         struct acpi_battery *battery = seq->private;
488
489         if (result)
490                 goto end;
491
492         seq_printf(seq, "present:                 %s\n",
493                    acpi_battery_present(battery)?"yes":"no");
494         if (!acpi_battery_present(battery))
495                 goto end;
496         if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
497                 seq_printf(seq, "design capacity:         unknown\n");
498         else
499                 seq_printf(seq, "design capacity:         %d %sh\n",
500                            battery->design_capacity,
501                            acpi_battery_units(battery));
502
503         if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
504                 seq_printf(seq, "last full capacity:      unknown\n");
505         else
506                 seq_printf(seq, "last full capacity:      %d %sh\n",
507                            battery->full_charge_capacity,
508                            acpi_battery_units(battery));
509
510         seq_printf(seq, "battery technology:      %srechargeable\n",
511                    (!battery->technology)?"non-":"");
512
513         if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
514                 seq_printf(seq, "design voltage:          unknown\n");
515         else
516                 seq_printf(seq, "design voltage:          %d mV\n",
517                            battery->design_voltage);
518         seq_printf(seq, "design capacity warning: %d %sh\n",
519                    battery->design_capacity_warning,
520                    acpi_battery_units(battery));
521         seq_printf(seq, "design capacity low:     %d %sh\n",
522                    battery->design_capacity_low,
523                    acpi_battery_units(battery));
524         seq_printf(seq, "capacity granularity 1:  %d %sh\n",
525                    battery->capacity_granularity_1,
526                    acpi_battery_units(battery));
527         seq_printf(seq, "capacity granularity 2:  %d %sh\n",
528                    battery->capacity_granularity_2,
529                    acpi_battery_units(battery));
530         seq_printf(seq, "model number:            %s\n", battery->model_number);
531         seq_printf(seq, "serial number:           %s\n", battery->serial_number);
532         seq_printf(seq, "battery type:            %s\n", battery->type);
533         seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
534       end:
535         if (result)
536                 seq_printf(seq, "ERROR: Unable to read battery info\n");
537         return result;
538 }
539
540 static int acpi_battery_print_state(struct seq_file *seq, int result)
541 {
542         struct acpi_battery *battery = seq->private;
543
544         if (result)
545                 goto end;
546
547         seq_printf(seq, "present:                 %s\n",
548                    acpi_battery_present(battery)?"yes":"no");
549         if (!acpi_battery_present(battery))
550                 goto end;
551
552         seq_printf(seq, "capacity state:          %s\n",
553                         (battery->state & 0x04)?"critical":"ok");
554         if ((battery->state & 0x01) && (battery->state & 0x02))
555                 seq_printf(seq,
556                            "charging state:          charging/discharging\n");
557         else if (battery->state & 0x01)
558                 seq_printf(seq, "charging state:          discharging\n");
559         else if (battery->state & 0x02)
560                 seq_printf(seq, "charging state:          charging\n");
561         else
562                 seq_printf(seq, "charging state:          charged\n");
563
564         if (battery->current_now == ACPI_BATTERY_VALUE_UNKNOWN)
565                 seq_printf(seq, "present rate:            unknown\n");
566         else
567                 seq_printf(seq, "present rate:            %d %s\n",
568                            battery->current_now, acpi_battery_units(battery));
569
570         if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
571                 seq_printf(seq, "remaining capacity:      unknown\n");
572         else
573                 seq_printf(seq, "remaining capacity:      %d %sh\n",
574                            battery->capacity_now, acpi_battery_units(battery));
575         if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
576                 seq_printf(seq, "present voltage:         unknown\n");
577         else
578                 seq_printf(seq, "present voltage:         %d mV\n",
579                            battery->voltage_now);
580       end:
581         if (result)
582                 seq_printf(seq, "ERROR: Unable to read battery state\n");
583
584         return result;
585 }
586
587 static int acpi_battery_print_alarm(struct seq_file *seq, int result)
588 {
589         struct acpi_battery *battery = seq->private;
590
591         if (result)
592                 goto end;
593
594         if (!acpi_battery_present(battery)) {
595                 seq_printf(seq, "present:                 no\n");
596                 goto end;
597         }
598         seq_printf(seq, "alarm:                   ");
599         if (!battery->alarm)
600                 seq_printf(seq, "unsupported\n");
601         else
602                 seq_printf(seq, "%u %sh\n", battery->alarm,
603                                 acpi_battery_units(battery));
604       end:
605         if (result)
606                 seq_printf(seq, "ERROR: Unable to read battery alarm\n");
607         return result;
608 }
609
610 static ssize_t acpi_battery_write_alarm(struct file *file,
611                                         const char __user * buffer,
612                                         size_t count, loff_t * ppos)
613 {
614         int result = 0;
615         char alarm_string[12] = { '\0' };
616         struct seq_file *m = file->private_data;
617         struct acpi_battery *battery = m->private;
618
619         if (!battery || (count > sizeof(alarm_string) - 1))
620                 return -EINVAL;
621         if (!acpi_battery_present(battery)) {
622                 result = -ENODEV;
623                 goto end;
624         }
625         if (copy_from_user(alarm_string, buffer, count)) {
626                 result = -EFAULT;
627                 goto end;
628         }
629         alarm_string[count] = '\0';
630         battery->alarm = simple_strtol(alarm_string, NULL, 0);
631         result = acpi_battery_set_alarm(battery);
632       end:
633         if (!result)
634                 return count;
635         return result;
636 }
637
638 typedef int(*print_func)(struct seq_file *seq, int result);
639
640 static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
641         acpi_battery_print_info,
642         acpi_battery_print_state,
643         acpi_battery_print_alarm,
644 };
645
646 static int acpi_battery_read(int fid, struct seq_file *seq)
647 {
648         struct acpi_battery *battery = seq->private;
649         int result = acpi_battery_update(battery);
650         return acpi_print_funcs[fid](seq, result);
651 }
652
653 #define DECLARE_FILE_FUNCTIONS(_name) \
654 static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
655 { \
656         return acpi_battery_read(_name##_tag, seq); \
657 } \
658 static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
659 { \
660         return single_open(file, acpi_battery_read_##_name, PDE(inode)->data); \
661 }
662
663 DECLARE_FILE_FUNCTIONS(info);
664 DECLARE_FILE_FUNCTIONS(state);
665 DECLARE_FILE_FUNCTIONS(alarm);
666
667 #undef DECLARE_FILE_FUNCTIONS
668
669 #define FILE_DESCRIPTION_RO(_name) \
670         { \
671         .name = __stringify(_name), \
672         .mode = S_IRUGO, \
673         .ops = { \
674                 .open = acpi_battery_##_name##_open_fs, \
675                 .read = seq_read, \
676                 .llseek = seq_lseek, \
677                 .release = single_release, \
678                 .owner = THIS_MODULE, \
679                 }, \
680         }
681
682 #define FILE_DESCRIPTION_RW(_name) \
683         { \
684         .name = __stringify(_name), \
685         .mode = S_IFREG | S_IRUGO | S_IWUSR, \
686         .ops = { \
687                 .open = acpi_battery_##_name##_open_fs, \
688                 .read = seq_read, \
689                 .llseek = seq_lseek, \
690                 .write = acpi_battery_write_##_name, \
691                 .release = single_release, \
692                 .owner = THIS_MODULE, \
693                 }, \
694         }
695
696 static struct battery_file {
697         struct file_operations ops;
698         mode_t mode;
699         char *name;
700 } acpi_battery_file[] = {
701         FILE_DESCRIPTION_RO(info),
702         FILE_DESCRIPTION_RO(state),
703         FILE_DESCRIPTION_RW(alarm),
704 };
705
706 #undef FILE_DESCRIPTION_RO
707 #undef FILE_DESCRIPTION_RW
708
709 static int acpi_battery_add_fs(struct acpi_device *device)
710 {
711         struct proc_dir_entry *entry = NULL;
712         int i;
713
714         if (!acpi_device_dir(device)) {
715                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
716                                                      acpi_battery_dir);
717                 if (!acpi_device_dir(device))
718                         return -ENODEV;
719                 acpi_device_dir(device)->owner = THIS_MODULE;
720         }
721
722         for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
723                 entry = create_proc_entry(acpi_battery_file[i].name,
724                                   acpi_battery_file[i].mode, acpi_device_dir(device));
725                 if (!entry)
726                         return -ENODEV;
727                 else {
728                         entry->proc_fops = &acpi_battery_file[i].ops;
729                         entry->data = acpi_driver_data(device);
730                         entry->owner = THIS_MODULE;
731                 }
732         }
733         return 0;
734 }
735
736 static void acpi_battery_remove_fs(struct acpi_device *device)
737 {
738         int i;
739         if (!acpi_device_dir(device))
740                 return;
741         for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
742                 remove_proc_entry(acpi_battery_file[i].name,
743                                   acpi_device_dir(device));
744
745         remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
746         acpi_device_dir(device) = NULL;
747 }
748
749 #endif
750
751 /* --------------------------------------------------------------------------
752                                  Driver Interface
753    -------------------------------------------------------------------------- */
754
755 static void acpi_battery_notify(acpi_handle handle, u32 event, void *data)
756 {
757         struct acpi_battery *battery = data;
758         struct acpi_device *device;
759         if (!battery)
760                 return;
761         device = battery->device;
762         acpi_battery_update(battery);
763         acpi_bus_generate_proc_event(device, event,
764                                      acpi_battery_present(battery));
765         acpi_bus_generate_netlink_event(device->pnp.device_class,
766                                         device->dev.bus_id, event,
767                                         acpi_battery_present(battery));
768         /* acpi_batter_update could remove power_supply object */
769         if (battery->bat.dev)
770                 kobject_uevent(&battery->bat.dev->kobj, KOBJ_CHANGE);
771 }
772
773 static int acpi_battery_add(struct acpi_device *device)
774 {
775         int result = 0;
776         acpi_status status = 0;
777         struct acpi_battery *battery = NULL;
778         if (!device)
779                 return -EINVAL;
780         battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
781         if (!battery)
782                 return -ENOMEM;
783         battery->device = device;
784         strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
785         strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
786         acpi_driver_data(device) = battery;
787         mutex_init(&battery->lock);
788         acpi_battery_update(battery);
789 #ifdef CONFIG_ACPI_PROCFS
790         result = acpi_battery_add_fs(device);
791         if (result)
792                 goto end;
793 #endif
794         status = acpi_install_notify_handler(device->handle,
795                                              ACPI_ALL_NOTIFY,
796                                              acpi_battery_notify, battery);
797         if (ACPI_FAILURE(status)) {
798                 ACPI_EXCEPTION((AE_INFO, status, "Installing notify handler"));
799                 result = -ENODEV;
800                 goto end;
801         }
802         printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
803                ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
804                device->status.battery_present ? "present" : "absent");
805       end:
806         if (result) {
807 #ifdef CONFIG_ACPI_PROCFS
808                 acpi_battery_remove_fs(device);
809 #endif
810                 kfree(battery);
811         }
812         return result;
813 }
814
815 static int acpi_battery_remove(struct acpi_device *device, int type)
816 {
817         acpi_status status = 0;
818         struct acpi_battery *battery = NULL;
819
820         if (!device || !acpi_driver_data(device))
821                 return -EINVAL;
822         battery = acpi_driver_data(device);
823         status = acpi_remove_notify_handler(device->handle,
824                                             ACPI_ALL_NOTIFY,
825                                             acpi_battery_notify);
826 #ifdef CONFIG_ACPI_PROCFS
827         acpi_battery_remove_fs(device);
828 #endif
829         sysfs_remove_battery(battery);
830         mutex_destroy(&battery->lock);
831         kfree(battery);
832         return 0;
833 }
834
835 /* this is needed to learn about changes made in suspended state */
836 static int acpi_battery_resume(struct acpi_device *device)
837 {
838         struct acpi_battery *battery;
839         if (!device)
840                 return -EINVAL;
841         battery = acpi_driver_data(device);
842         battery->update_time = 0;
843         acpi_battery_update(battery);
844         return 0;
845 }
846
847 static struct acpi_driver acpi_battery_driver = {
848         .name = "battery",
849         .class = ACPI_BATTERY_CLASS,
850         .ids = battery_device_ids,
851         .ops = {
852                 .add = acpi_battery_add,
853                 .resume = acpi_battery_resume,
854                 .remove = acpi_battery_remove,
855                 },
856 };
857
858 static int __init acpi_battery_init(void)
859 {
860         if (acpi_disabled)
861                 return -ENODEV;
862 #ifdef CONFIG_ACPI_PROCFS
863         acpi_battery_dir = acpi_lock_battery_dir();
864         if (!acpi_battery_dir)
865                 return -ENODEV;
866 #endif
867         if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
868 #ifdef CONFIG_ACPI_PROCFS
869                 acpi_unlock_battery_dir(acpi_battery_dir);
870 #endif
871                 return -ENODEV;
872         }
873         return 0;
874 }
875
876 static void __exit acpi_battery_exit(void)
877 {
878         acpi_bus_unregister_driver(&acpi_battery_driver);
879 #ifdef CONFIG_ACPI_PROCFS
880         acpi_unlock_battery_dir(acpi_battery_dir);
881 #endif
882 }
883
884 module_init(acpi_battery_init);
885 module_exit(acpi_battery_exit);