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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * lg-laptop.c - LG Gram ACPI features and hotkeys Driver
4 *
5 * Copyright (C) 2018 Matan Ziv-Av <matan@svgalib.org>
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/acpi.h>
11#include <linux/dmi.h>
12#include <linux/input.h>
13#include <linux/input/sparse-keymap.h>
14#include <linux/kernel.h>
15#include <linux/leds.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18#include <linux/types.h>
19
20#include <acpi/battery.h>
21
22#define LED_DEVICE(_name, max, flag) struct led_classdev _name = { \
23 .name = __stringify(_name), \
24 .max_brightness = max, \
25 .brightness_set = _name##_set, \
26 .brightness_get = _name##_get, \
27 .flags = flag, \
28}
29
30MODULE_AUTHOR("Matan Ziv-Av");
31MODULE_DESCRIPTION("LG WMI Hotkey Driver");
32MODULE_LICENSE("GPL");
33
34#define WMI_EVENT_GUID0 "E4FB94F9-7F2B-4173-AD1A-CD1D95086248"
35#define WMI_EVENT_GUID1 "023B133E-49D1-4E10-B313-698220140DC2"
36#define WMI_EVENT_GUID2 "37BE1AC0-C3F2-4B1F-BFBE-8FDEAF2814D6"
37#define WMI_EVENT_GUID3 "911BAD44-7DF8-4FBB-9319-BABA1C4B293B"
38#define WMI_METHOD_WMAB "C3A72B38-D3EF-42D3-8CBB-D5A57049F66D"
39#define WMI_METHOD_WMBB "2B4F501A-BD3C-4394-8DCF-00A7D2BC8210"
40#define WMI_EVENT_GUID WMI_EVENT_GUID0
41
42#define WMAB_METHOD "\\XINI.WMAB"
43#define WMBB_METHOD "\\XINI.WMBB"
44#define SB_GGOV_METHOD "\\_SB.GGOV"
45#define GOV_TLED 0x2020008
46#define WM_GET 1
47#define WM_SET 2
48#define WM_KEY_LIGHT 0x400
49#define WM_TLED 0x404
50#define WM_FN_LOCK 0x407
51#define WM_BATT_LIMIT 0x61
52#define WM_READER_MODE 0xBF
53#define WM_FAN_MODE 0x33
54#define WMBB_USB_CHARGE 0x10B
55#define WMBB_BATT_LIMIT 0x10C
56
57#define PLATFORM_NAME "lg-laptop"
58
59MODULE_ALIAS("wmi:" WMI_EVENT_GUID0);
60MODULE_ALIAS("wmi:" WMI_EVENT_GUID1);
61MODULE_ALIAS("wmi:" WMI_EVENT_GUID2);
62MODULE_ALIAS("wmi:" WMI_EVENT_GUID3);
63MODULE_ALIAS("wmi:" WMI_METHOD_WMAB);
64MODULE_ALIAS("wmi:" WMI_METHOD_WMBB);
65
66static struct platform_device *pf_device;
67static struct input_dev *wmi_input_dev;
68
69static u32 inited;
70#define INIT_INPUT_WMI_0 0x01
71#define INIT_INPUT_WMI_2 0x02
72#define INIT_INPUT_ACPI 0x04
73#define INIT_SPARSE_KEYMAP 0x80
74
75static int battery_limit_use_wmbb;
76static struct led_classdev kbd_backlight;
77static enum led_brightness get_kbd_backlight_level(void);
78
79static const struct key_entry wmi_keymap[] = {
80 {KE_KEY, 0x70, {KEY_F15} }, /* LG control panel (F1) */
81 {KE_KEY, 0x74, {KEY_F21} }, /* Touchpad toggle (F5) */
82 {KE_KEY, 0xf020000, {KEY_F14} }, /* Read mode (F9) */
83 {KE_KEY, 0x10000000, {KEY_F16} },/* Keyboard backlight (F8) - pressing
84 * this key both sends an event and
85 * changes backlight level.
86 */
87 {KE_KEY, 0x80, {KEY_RFKILL} },
88 {KE_END, 0}
89};
90
91static int ggov(u32 arg0)
92{
93 union acpi_object args[1];
94 union acpi_object *r;
95 acpi_status status;
96 acpi_handle handle;
97 struct acpi_object_list arg;
98 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
99 int res;
100
101 args[0].type = ACPI_TYPE_INTEGER;
102 args[0].integer.value = arg0;
103
104 status = acpi_get_handle(NULL, (acpi_string) SB_GGOV_METHOD, &handle);
105 if (ACPI_FAILURE(status)) {
106 pr_err("Cannot get handle");
107 return -ENODEV;
108 }
109
110 arg.count = 1;
111 arg.pointer = args;
112
113 status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
114 if (ACPI_FAILURE(status)) {
115 acpi_handle_err(handle, "GGOV: call failed.\n");
116 return -EINVAL;
117 }
118
119 r = buffer.pointer;
120 if (r->type != ACPI_TYPE_INTEGER) {
121 kfree(r);
122 return -EINVAL;
123 }
124
125 res = r->integer.value;
126 kfree(r);
127
128 return res;
129}
130
131static union acpi_object *lg_wmab(u32 method, u32 arg1, u32 arg2)
132{
133 union acpi_object args[3];
134 acpi_status status;
135 acpi_handle handle;
136 struct acpi_object_list arg;
137 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
138
139 args[0].type = ACPI_TYPE_INTEGER;
140 args[0].integer.value = method;
141 args[1].type = ACPI_TYPE_INTEGER;
142 args[1].integer.value = arg1;
143 args[2].type = ACPI_TYPE_INTEGER;
144 args[2].integer.value = arg2;
145
146 status = acpi_get_handle(NULL, (acpi_string) WMAB_METHOD, &handle);
147 if (ACPI_FAILURE(status)) {
148 pr_err("Cannot get handle");
149 return NULL;
150 }
151
152 arg.count = 3;
153 arg.pointer = args;
154
155 status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
156 if (ACPI_FAILURE(status)) {
157 acpi_handle_err(handle, "WMAB: call failed.\n");
158 return NULL;
159 }
160
161 return buffer.pointer;
162}
163
164static union acpi_object *lg_wmbb(u32 method_id, u32 arg1, u32 arg2)
165{
166 union acpi_object args[3];
167 acpi_status status;
168 acpi_handle handle;
169 struct acpi_object_list arg;
170 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
171 u8 buf[32];
172
173 *(u32 *)buf = method_id;
174 *(u32 *)(buf + 4) = arg1;
175 *(u32 *)(buf + 16) = arg2;
176 args[0].type = ACPI_TYPE_INTEGER;
177 args[0].integer.value = 0; /* ignored */
178 args[1].type = ACPI_TYPE_INTEGER;
179 args[1].integer.value = 1; /* Must be 1 or 2. Does not matter which */
180 args[2].type = ACPI_TYPE_BUFFER;
181 args[2].buffer.length = 32;
182 args[2].buffer.pointer = buf;
183
184 status = acpi_get_handle(NULL, (acpi_string)WMBB_METHOD, &handle);
185 if (ACPI_FAILURE(status)) {
186 pr_err("Cannot get handle");
187 return NULL;
188 }
189
190 arg.count = 3;
191 arg.pointer = args;
192
193 status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
194 if (ACPI_FAILURE(status)) {
195 acpi_handle_err(handle, "WMAB: call failed.\n");
196 return NULL;
197 }
198
199 return (union acpi_object *)buffer.pointer;
200}
201
202static void wmi_notify(u32 value, void *context)
203{
204 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
205 union acpi_object *obj;
206 acpi_status status;
207 long data = (long)context;
208
209 pr_debug("event guid %li\n", data);
210 status = wmi_get_event_data(value, &response);
211 if (ACPI_FAILURE(status)) {
212 pr_err("Bad event status 0x%x\n", status);
213 return;
214 }
215
216 obj = (union acpi_object *)response.pointer;
217 if (!obj)
218 return;
219
220 if (obj->type == ACPI_TYPE_INTEGER) {
221 int eventcode = obj->integer.value;
222 struct key_entry *key;
223
224 if (eventcode == 0x10000000) {
225 led_classdev_notify_brightness_hw_changed(
226 &kbd_backlight, get_kbd_backlight_level());
227 } else {
228 key = sparse_keymap_entry_from_scancode(
229 wmi_input_dev, eventcode);
230 if (key && key->type == KE_KEY)
231 sparse_keymap_report_entry(wmi_input_dev,
232 key, 1, true);
233 }
234 }
235
236 pr_debug("Type: %i Eventcode: 0x%llx\n", obj->type,
237 obj->integer.value);
238 kfree(response.pointer);
239}
240
241static void wmi_input_setup(void)
242{
243 acpi_status status;
244
245 wmi_input_dev = input_allocate_device();
246 if (wmi_input_dev) {
247 wmi_input_dev->name = "LG WMI hotkeys";
248 wmi_input_dev->phys = "wmi/input0";
249 wmi_input_dev->id.bustype = BUS_HOST;
250
251 if (sparse_keymap_setup(wmi_input_dev, wmi_keymap, NULL) ||
252 input_register_device(wmi_input_dev)) {
253 pr_info("Cannot initialize input device");
254 input_free_device(wmi_input_dev);
255 return;
256 }
257
258 inited |= INIT_SPARSE_KEYMAP;
259 status = wmi_install_notify_handler(WMI_EVENT_GUID0, wmi_notify,
260 (void *)0);
261 if (ACPI_SUCCESS(status))
262 inited |= INIT_INPUT_WMI_0;
263
264 status = wmi_install_notify_handler(WMI_EVENT_GUID2, wmi_notify,
265 (void *)2);
266 if (ACPI_SUCCESS(status))
267 inited |= INIT_INPUT_WMI_2;
268 } else {
269 pr_info("Cannot allocate input device");
270 }
271}
272
273static void acpi_notify(struct acpi_device *device, u32 event)
274{
275 struct key_entry *key;
276
277 acpi_handle_debug(device->handle, "notify: %d\n", event);
278 if (inited & INIT_SPARSE_KEYMAP) {
279 key = sparse_keymap_entry_from_scancode(wmi_input_dev, 0x80);
280 if (key && key->type == KE_KEY)
281 sparse_keymap_report_entry(wmi_input_dev, key, 1, true);
282 }
283}
284
285static ssize_t fan_mode_store(struct device *dev,
286 struct device_attribute *attr,
287 const char *buffer, size_t count)
288{
289 bool value;
290 union acpi_object *r;
291 u32 m;
292 int ret;
293
294 ret = kstrtobool(buffer, &value);
295 if (ret)
296 return ret;
297
298 r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
299 if (!r)
300 return -EIO;
301
302 if (r->type != ACPI_TYPE_INTEGER) {
303 kfree(r);
304 return -EIO;
305 }
306
307 m = r->integer.value;
308 kfree(r);
309 r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xffffff0f) | (value << 4));
310 kfree(r);
311 r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xfffffff0) | value);
312 kfree(r);
313
314 return count;
315}
316
317static ssize_t fan_mode_show(struct device *dev,
318 struct device_attribute *attr, char *buffer)
319{
320 unsigned int status;
321 union acpi_object *r;
322
323 r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
324 if (!r)
325 return -EIO;
326
327 if (r->type != ACPI_TYPE_INTEGER) {
328 kfree(r);
329 return -EIO;
330 }
331
332 status = r->integer.value & 0x01;
333 kfree(r);
334
335 return sysfs_emit(buffer, "%d\n", status);
336}
337
338static ssize_t usb_charge_store(struct device *dev,
339 struct device_attribute *attr,
340 const char *buffer, size_t count)
341{
342 bool value;
343 union acpi_object *r;
344 int ret;
345
346 ret = kstrtobool(buffer, &value);
347 if (ret)
348 return ret;
349
350 r = lg_wmbb(WMBB_USB_CHARGE, WM_SET, value);
351 if (!r)
352 return -EIO;
353
354 kfree(r);
355 return count;
356}
357
358static ssize_t usb_charge_show(struct device *dev,
359 struct device_attribute *attr, char *buffer)
360{
361 unsigned int status;
362 union acpi_object *r;
363
364 r = lg_wmbb(WMBB_USB_CHARGE, WM_GET, 0);
365 if (!r)
366 return -EIO;
367
368 if (r->type != ACPI_TYPE_BUFFER) {
369 kfree(r);
370 return -EIO;
371 }
372
373 status = !!r->buffer.pointer[0x10];
374
375 kfree(r);
376
377 return sysfs_emit(buffer, "%d\n", status);
378}
379
380static ssize_t reader_mode_store(struct device *dev,
381 struct device_attribute *attr,
382 const char *buffer, size_t count)
383{
384 bool value;
385 union acpi_object *r;
386 int ret;
387
388 ret = kstrtobool(buffer, &value);
389 if (ret)
390 return ret;
391
392 r = lg_wmab(WM_READER_MODE, WM_SET, value);
393 if (!r)
394 return -EIO;
395
396 kfree(r);
397 return count;
398}
399
400static ssize_t reader_mode_show(struct device *dev,
401 struct device_attribute *attr, char *buffer)
402{
403 unsigned int status;
404 union acpi_object *r;
405
406 r = lg_wmab(WM_READER_MODE, WM_GET, 0);
407 if (!r)
408 return -EIO;
409
410 if (r->type != ACPI_TYPE_INTEGER) {
411 kfree(r);
412 return -EIO;
413 }
414
415 status = !!r->integer.value;
416
417 kfree(r);
418
419 return sysfs_emit(buffer, "%d\n", status);
420}
421
422static ssize_t fn_lock_store(struct device *dev,
423 struct device_attribute *attr,
424 const char *buffer, size_t count)
425{
426 bool value;
427 union acpi_object *r;
428 int ret;
429
430 ret = kstrtobool(buffer, &value);
431 if (ret)
432 return ret;
433
434 r = lg_wmab(WM_FN_LOCK, WM_SET, value);
435 if (!r)
436 return -EIO;
437
438 kfree(r);
439 return count;
440}
441
442static ssize_t fn_lock_show(struct device *dev,
443 struct device_attribute *attr, char *buffer)
444{
445 unsigned int status;
446 union acpi_object *r;
447
448 r = lg_wmab(WM_FN_LOCK, WM_GET, 0);
449 if (!r)
450 return -EIO;
451
452 if (r->type != ACPI_TYPE_BUFFER) {
453 kfree(r);
454 return -EIO;
455 }
456
457 status = !!r->buffer.pointer[0];
458 kfree(r);
459
460 return sysfs_emit(buffer, "%d\n", status);
461}
462
463static ssize_t charge_control_end_threshold_store(struct device *dev,
464 struct device_attribute *attr,
465 const char *buf, size_t count)
466{
467 unsigned long value;
468 int ret;
469
470 ret = kstrtoul(buf, 10, &value);
471 if (ret)
472 return ret;
473
474 if (value == 100 || value == 80) {
475 union acpi_object *r;
476
477 if (battery_limit_use_wmbb)
478 r = lg_wmbb(WMBB_BATT_LIMIT, WM_SET, value);
479 else
480 r = lg_wmab(WM_BATT_LIMIT, WM_SET, value);
481 if (!r)
482 return -EIO;
483
484 kfree(r);
485 return count;
486 }
487
488 return -EINVAL;
489}
490
491static ssize_t charge_control_end_threshold_show(struct device *device,
492 struct device_attribute *attr,
493 char *buf)
494{
495 unsigned int status;
496 union acpi_object *r;
497
498 if (battery_limit_use_wmbb) {
499 r = lg_wmbb(WMBB_BATT_LIMIT, WM_GET, 0);
500 if (!r)
501 return -EIO;
502
503 if (r->type != ACPI_TYPE_BUFFER) {
504 kfree(r);
505 return -EIO;
506 }
507
508 status = r->buffer.pointer[0x10];
509 } else {
510 r = lg_wmab(WM_BATT_LIMIT, WM_GET, 0);
511 if (!r)
512 return -EIO;
513
514 if (r->type != ACPI_TYPE_INTEGER) {
515 kfree(r);
516 return -EIO;
517 }
518
519 status = r->integer.value;
520 }
521 kfree(r);
522 if (status != 80 && status != 100)
523 status = 0;
524
525 return sysfs_emit(buf, "%d\n", status);
526}
527
528static ssize_t battery_care_limit_show(struct device *dev,
529 struct device_attribute *attr,
530 char *buffer)
531{
532 return charge_control_end_threshold_show(dev, attr, buffer);
533}
534
535static ssize_t battery_care_limit_store(struct device *dev,
536 struct device_attribute *attr,
537 const char *buffer, size_t count)
538{
539 return charge_control_end_threshold_store(dev, attr, buffer, count);
540}
541
542static DEVICE_ATTR_RW(fan_mode);
543static DEVICE_ATTR_RW(usb_charge);
544static DEVICE_ATTR_RW(reader_mode);
545static DEVICE_ATTR_RW(fn_lock);
546static DEVICE_ATTR_RW(charge_control_end_threshold);
547static DEVICE_ATTR_RW(battery_care_limit);
548
549static int lg_battery_add(struct power_supply *battery, struct acpi_battery_hook *hook)
550{
551 if (device_create_file(&battery->dev,
552 &dev_attr_charge_control_end_threshold))
553 return -ENODEV;
554
555 return 0;
556}
557
558static int lg_battery_remove(struct power_supply *battery, struct acpi_battery_hook *hook)
559{
560 device_remove_file(&battery->dev,
561 &dev_attr_charge_control_end_threshold);
562 return 0;
563}
564
565static struct acpi_battery_hook battery_hook = {
566 .add_battery = lg_battery_add,
567 .remove_battery = lg_battery_remove,
568 .name = "LG Battery Extension",
569};
570
571static struct attribute *dev_attributes[] = {
572 &dev_attr_fan_mode.attr,
573 &dev_attr_usb_charge.attr,
574 &dev_attr_reader_mode.attr,
575 &dev_attr_fn_lock.attr,
576 &dev_attr_battery_care_limit.attr,
577 NULL
578};
579
580static const struct attribute_group dev_attribute_group = {
581 .attrs = dev_attributes,
582};
583
584static void tpad_led_set(struct led_classdev *cdev,
585 enum led_brightness brightness)
586{
587 union acpi_object *r;
588
589 r = lg_wmab(WM_TLED, WM_SET, brightness > LED_OFF);
590 kfree(r);
591}
592
593static enum led_brightness tpad_led_get(struct led_classdev *cdev)
594{
595 return ggov(GOV_TLED) > 0 ? LED_ON : LED_OFF;
596}
597
598static LED_DEVICE(tpad_led, 1, 0);
599
600static void kbd_backlight_set(struct led_classdev *cdev,
601 enum led_brightness brightness)
602{
603 u32 val;
604 union acpi_object *r;
605
606 val = 0x22;
607 if (brightness <= LED_OFF)
608 val = 0;
609 if (brightness >= LED_FULL)
610 val = 0x24;
611 r = lg_wmab(WM_KEY_LIGHT, WM_SET, val);
612 kfree(r);
613}
614
615static enum led_brightness get_kbd_backlight_level(void)
616{
617 union acpi_object *r;
618 int val;
619
620 r = lg_wmab(WM_KEY_LIGHT, WM_GET, 0);
621
622 if (!r)
623 return LED_OFF;
624
625 if (r->type != ACPI_TYPE_BUFFER || r->buffer.pointer[1] != 0x05) {
626 kfree(r);
627 return LED_OFF;
628 }
629
630 switch (r->buffer.pointer[0] & 0x27) {
631 case 0x24:
632 val = LED_FULL;
633 break;
634 case 0x22:
635 val = LED_HALF;
636 break;
637 default:
638 val = LED_OFF;
639 }
640
641 kfree(r);
642
643 return val;
644}
645
646static enum led_brightness kbd_backlight_get(struct led_classdev *cdev)
647{
648 return get_kbd_backlight_level();
649}
650
651static LED_DEVICE(kbd_backlight, 255, LED_BRIGHT_HW_CHANGED);
652
653static void wmi_input_destroy(void)
654{
655 if (inited & INIT_INPUT_WMI_2)
656 wmi_remove_notify_handler(WMI_EVENT_GUID2);
657
658 if (inited & INIT_INPUT_WMI_0)
659 wmi_remove_notify_handler(WMI_EVENT_GUID0);
660
661 if (inited & INIT_SPARSE_KEYMAP)
662 input_unregister_device(wmi_input_dev);
663
664 inited &= ~(INIT_INPUT_WMI_0 | INIT_INPUT_WMI_2 | INIT_SPARSE_KEYMAP);
665}
666
667static struct platform_driver pf_driver = {
668 .driver = {
669 .name = PLATFORM_NAME,
670 }
671};
672
673static int acpi_add(struct acpi_device *device)
674{
675 int ret;
676 const char *product;
677 int year = 2017;
678
679 if (pf_device)
680 return 0;
681
682 ret = platform_driver_register(&pf_driver);
683 if (ret)
684 return ret;
685
686 pf_device = platform_device_register_simple(PLATFORM_NAME,
687 PLATFORM_DEVID_NONE,
688 NULL, 0);
689 if (IS_ERR(pf_device)) {
690 ret = PTR_ERR(pf_device);
691 pf_device = NULL;
692 pr_err("unable to register platform device\n");
693 goto out_platform_registered;
694 }
695 product = dmi_get_system_info(DMI_PRODUCT_NAME);
696 if (product && strlen(product) > 4)
697 switch (product[4]) {
698 case '5':
699 if (strlen(product) > 5)
700 switch (product[5]) {
701 case 'N':
702 year = 2021;
703 break;
704 case '0':
705 year = 2016;
706 break;
707 default:
708 year = 2022;
709 }
710 break;
711 case '6':
712 year = 2016;
713 break;
714 case '7':
715 year = 2017;
716 break;
717 case '8':
718 year = 2018;
719 break;
720 case '9':
721 year = 2019;
722 break;
723 case '0':
724 if (strlen(product) > 5)
725 switch (product[5]) {
726 case 'N':
727 year = 2020;
728 break;
729 case 'P':
730 year = 2021;
731 break;
732 default:
733 year = 2022;
734 }
735 break;
736 default:
737 year = 2019;
738 }
739 pr_info("product: %s year: %d\n", product, year);
740
741 if (year >= 2019)
742 battery_limit_use_wmbb = 1;
743
744 ret = sysfs_create_group(&pf_device->dev.kobj, &dev_attribute_group);
745 if (ret)
746 goto out_platform_device;
747
748 /* LEDs are optional */
749 led_classdev_register(&pf_device->dev, &kbd_backlight);
750 led_classdev_register(&pf_device->dev, &tpad_led);
751
752 wmi_input_setup();
753 battery_hook_register(&battery_hook);
754
755 return 0;
756
757out_platform_device:
758 platform_device_unregister(pf_device);
759out_platform_registered:
760 platform_driver_unregister(&pf_driver);
761 return ret;
762}
763
764static void acpi_remove(struct acpi_device *device)
765{
766 sysfs_remove_group(&pf_device->dev.kobj, &dev_attribute_group);
767
768 led_classdev_unregister(&tpad_led);
769 led_classdev_unregister(&kbd_backlight);
770
771 battery_hook_unregister(&battery_hook);
772 wmi_input_destroy();
773 platform_device_unregister(pf_device);
774 pf_device = NULL;
775 platform_driver_unregister(&pf_driver);
776}
777
778static const struct acpi_device_id device_ids[] = {
779 {"LGEX0815", 0},
780 {"", 0}
781};
782MODULE_DEVICE_TABLE(acpi, device_ids);
783
784static struct acpi_driver acpi_driver = {
785 .name = "LG Gram Laptop Support",
786 .class = "lg-laptop",
787 .ids = device_ids,
788 .ops = {
789 .add = acpi_add,
790 .remove = acpi_remove,
791 .notify = acpi_notify,
792 },
793 .owner = THIS_MODULE,
794};
795
796static int __init acpi_init(void)
797{
798 int result;
799
800 result = acpi_bus_register_driver(&acpi_driver);
801 if (result < 0) {
802 pr_debug("Error registering driver\n");
803 return -ENODEV;
804 }
805
806 return 0;
807}
808
809static void __exit acpi_exit(void)
810{
811 acpi_bus_unregister_driver(&acpi_driver);
812}
813
814module_init(acpi_init);
815module_exit(acpi_exit);