xref: /openbmc/linux/drivers/platform/x86/lg-laptop.c (revision 25b892b5)
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 #define LED_DEVICE(_name, max, flag) struct led_classdev _name = { \
21 	.name           = __stringify(_name),   \
22 	.max_brightness = max,                  \
23 	.brightness_set = _name##_set,          \
24 	.brightness_get = _name##_get,          \
25 	.flags = flag,                          \
26 }
27 
28 MODULE_AUTHOR("Matan Ziv-Av");
29 MODULE_DESCRIPTION("LG WMI Hotkey Driver");
30 MODULE_LICENSE("GPL");
31 
32 #define WMI_EVENT_GUID0	"E4FB94F9-7F2B-4173-AD1A-CD1D95086248"
33 #define WMI_EVENT_GUID1	"023B133E-49D1-4E10-B313-698220140DC2"
34 #define WMI_EVENT_GUID2	"37BE1AC0-C3F2-4B1F-BFBE-8FDEAF2814D6"
35 #define WMI_EVENT_GUID3	"911BAD44-7DF8-4FBB-9319-BABA1C4B293B"
36 #define WMI_METHOD_WMAB "C3A72B38-D3EF-42D3-8CBB-D5A57049F66D"
37 #define WMI_METHOD_WMBB "2B4F501A-BD3C-4394-8DCF-00A7D2BC8210"
38 #define WMI_EVENT_GUID  WMI_EVENT_GUID0
39 
40 #define WMAB_METHOD     "\\XINI.WMAB"
41 #define WMBB_METHOD     "\\XINI.WMBB"
42 #define SB_GGOV_METHOD  "\\_SB.GGOV"
43 #define GOV_TLED        0x2020008
44 #define WM_GET          1
45 #define WM_SET          2
46 #define WM_KEY_LIGHT    0x400
47 #define WM_TLED         0x404
48 #define WM_FN_LOCK      0x407
49 #define WM_BATT_LIMIT   0x61
50 #define WM_READER_MODE  0xBF
51 #define WM_FAN_MODE	0x33
52 #define WMBB_USB_CHARGE 0x10B
53 #define WMBB_BATT_LIMIT 0x10C
54 
55 #define PLATFORM_NAME   "lg-laptop"
56 
57 MODULE_ALIAS("wmi:" WMI_EVENT_GUID0);
58 MODULE_ALIAS("wmi:" WMI_EVENT_GUID1);
59 MODULE_ALIAS("wmi:" WMI_EVENT_GUID2);
60 MODULE_ALIAS("wmi:" WMI_EVENT_GUID3);
61 MODULE_ALIAS("wmi:" WMI_METHOD_WMAB);
62 MODULE_ALIAS("wmi:" WMI_METHOD_WMBB);
63 MODULE_ALIAS("acpi*:LGEX0815:*");
64 
65 static struct platform_device *pf_device;
66 static struct input_dev *wmi_input_dev;
67 
68 static u32 inited;
69 #define INIT_INPUT_WMI_0        0x01
70 #define INIT_INPUT_WMI_2        0x02
71 #define INIT_INPUT_ACPI         0x04
72 #define INIT_SPARSE_KEYMAP      0x80
73 
74 static int battery_limit_use_wmbb;
75 static struct led_classdev kbd_backlight;
76 static enum led_brightness get_kbd_backlight_level(void);
77 
78 static const struct key_entry wmi_keymap[] = {
79 	{KE_KEY, 0x70, {KEY_F15} },	 /* LG control panel (F1) */
80 	{KE_KEY, 0x74, {KEY_F21} },	 /* Touchpad toggle (F5) */
81 	{KE_KEY, 0xf020000, {KEY_F14} }, /* Read mode (F9) */
82 	{KE_KEY, 0x10000000, {KEY_F16} },/* Keyboard backlight (F8) - pressing
83 					  * this key both sends an event and
84 					  * changes backlight level.
85 					  */
86 	{KE_KEY, 0x80, {KEY_RFKILL} },
87 	{KE_END, 0}
88 };
89 
90 static int ggov(u32 arg0)
91 {
92 	union acpi_object args[1];
93 	union acpi_object *r;
94 	acpi_status status;
95 	acpi_handle handle;
96 	struct acpi_object_list arg;
97 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
98 	int res;
99 
100 	args[0].type = ACPI_TYPE_INTEGER;
101 	args[0].integer.value = arg0;
102 
103 	status = acpi_get_handle(NULL, (acpi_string) SB_GGOV_METHOD, &handle);
104 	if (ACPI_FAILURE(status)) {
105 		pr_err("Cannot get handle");
106 		return -ENODEV;
107 	}
108 
109 	arg.count = 1;
110 	arg.pointer = args;
111 
112 	status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
113 	if (ACPI_FAILURE(status)) {
114 		acpi_handle_err(handle, "GGOV: call failed.\n");
115 		return -EINVAL;
116 	}
117 
118 	r = buffer.pointer;
119 	if (r->type != ACPI_TYPE_INTEGER) {
120 		kfree(r);
121 		return -EINVAL;
122 	}
123 
124 	res = r->integer.value;
125 	kfree(r);
126 
127 	return res;
128 }
129 
130 static union acpi_object *lg_wmab(u32 method, u32 arg1, u32 arg2)
131 {
132 	union acpi_object args[3];
133 	acpi_status status;
134 	acpi_handle handle;
135 	struct acpi_object_list arg;
136 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
137 
138 	args[0].type = ACPI_TYPE_INTEGER;
139 	args[0].integer.value = method;
140 	args[1].type = ACPI_TYPE_INTEGER;
141 	args[1].integer.value = arg1;
142 	args[2].type = ACPI_TYPE_INTEGER;
143 	args[2].integer.value = arg2;
144 
145 	status = acpi_get_handle(NULL, (acpi_string) WMAB_METHOD, &handle);
146 	if (ACPI_FAILURE(status)) {
147 		pr_err("Cannot get handle");
148 		return NULL;
149 	}
150 
151 	arg.count = 3;
152 	arg.pointer = args;
153 
154 	status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
155 	if (ACPI_FAILURE(status)) {
156 		acpi_handle_err(handle, "WMAB: call failed.\n");
157 		return NULL;
158 	}
159 
160 	return buffer.pointer;
161 }
162 
163 static union acpi_object *lg_wmbb(u32 method_id, u32 arg1, u32 arg2)
164 {
165 	union acpi_object args[3];
166 	acpi_status status;
167 	acpi_handle handle;
168 	struct acpi_object_list arg;
169 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
170 	u8 buf[32];
171 
172 	*(u32 *)buf = method_id;
173 	*(u32 *)(buf + 4) = arg1;
174 	*(u32 *)(buf + 16) = arg2;
175 	args[0].type = ACPI_TYPE_INTEGER;
176 	args[0].integer.value = 0; /* ignored */
177 	args[1].type = ACPI_TYPE_INTEGER;
178 	args[1].integer.value = 1; /* Must be 1 or 2. Does not matter which */
179 	args[2].type = ACPI_TYPE_BUFFER;
180 	args[2].buffer.length = 32;
181 	args[2].buffer.pointer = buf;
182 
183 	status = acpi_get_handle(NULL, (acpi_string)WMBB_METHOD, &handle);
184 	if (ACPI_FAILURE(status)) {
185 		pr_err("Cannot get handle");
186 		return NULL;
187 	}
188 
189 	arg.count = 3;
190 	arg.pointer = args;
191 
192 	status = acpi_evaluate_object(handle, NULL, &arg, &buffer);
193 	if (ACPI_FAILURE(status)) {
194 		acpi_handle_err(handle, "WMAB: call failed.\n");
195 		return NULL;
196 	}
197 
198 	return (union acpi_object *)buffer.pointer;
199 }
200 
201 static void wmi_notify(u32 value, void *context)
202 {
203 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
204 	union acpi_object *obj;
205 	acpi_status status;
206 	long data = (long)context;
207 
208 	pr_debug("event guid %li\n", data);
209 	status = wmi_get_event_data(value, &response);
210 	if (ACPI_FAILURE(status)) {
211 		pr_err("Bad event status 0x%x\n", status);
212 		return;
213 	}
214 
215 	obj = (union acpi_object *)response.pointer;
216 	if (!obj)
217 		return;
218 
219 	if (obj->type == ACPI_TYPE_INTEGER) {
220 		int eventcode = obj->integer.value;
221 		struct key_entry *key;
222 
223 		if (eventcode == 0x10000000) {
224 			led_classdev_notify_brightness_hw_changed(
225 				&kbd_backlight, get_kbd_backlight_level());
226 		} else {
227 			key = sparse_keymap_entry_from_scancode(
228 				wmi_input_dev, eventcode);
229 			if (key && key->type == KE_KEY)
230 				sparse_keymap_report_entry(wmi_input_dev,
231 							   key, 1, true);
232 		}
233 	}
234 
235 	pr_debug("Type: %i    Eventcode: 0x%llx\n", obj->type,
236 		 obj->integer.value);
237 	kfree(response.pointer);
238 }
239 
240 static void wmi_input_setup(void)
241 {
242 	acpi_status status;
243 
244 	wmi_input_dev = input_allocate_device();
245 	if (wmi_input_dev) {
246 		wmi_input_dev->name = "LG WMI hotkeys";
247 		wmi_input_dev->phys = "wmi/input0";
248 		wmi_input_dev->id.bustype = BUS_HOST;
249 
250 		if (sparse_keymap_setup(wmi_input_dev, wmi_keymap, NULL) ||
251 		    input_register_device(wmi_input_dev)) {
252 			pr_info("Cannot initialize input device");
253 			input_free_device(wmi_input_dev);
254 			return;
255 		}
256 
257 		inited |= INIT_SPARSE_KEYMAP;
258 		status = wmi_install_notify_handler(WMI_EVENT_GUID0, wmi_notify,
259 						    (void *)0);
260 		if (ACPI_SUCCESS(status))
261 			inited |= INIT_INPUT_WMI_0;
262 
263 		status = wmi_install_notify_handler(WMI_EVENT_GUID2, wmi_notify,
264 						    (void *)2);
265 		if (ACPI_SUCCESS(status))
266 			inited |= INIT_INPUT_WMI_2;
267 	} else {
268 		pr_info("Cannot allocate input device");
269 	}
270 }
271 
272 static void acpi_notify(struct acpi_device *device, u32 event)
273 {
274 	struct key_entry *key;
275 
276 	acpi_handle_debug(device->handle, "notify: %d\n", event);
277 	if (inited & INIT_SPARSE_KEYMAP) {
278 		key = sparse_keymap_entry_from_scancode(wmi_input_dev, 0x80);
279 		if (key && key->type == KE_KEY)
280 			sparse_keymap_report_entry(wmi_input_dev, key, 1, true);
281 	}
282 }
283 
284 static ssize_t fan_mode_store(struct device *dev,
285 			      struct device_attribute *attr,
286 			      const char *buffer, size_t count)
287 {
288 	bool value;
289 	union acpi_object *r;
290 	u32 m;
291 	int ret;
292 
293 	ret = kstrtobool(buffer, &value);
294 	if (ret)
295 		return ret;
296 
297 	r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
298 	if (!r)
299 		return -EIO;
300 
301 	if (r->type != ACPI_TYPE_INTEGER) {
302 		kfree(r);
303 		return -EIO;
304 	}
305 
306 	m = r->integer.value;
307 	kfree(r);
308 	r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xffffff0f) | (value << 4));
309 	kfree(r);
310 	r = lg_wmab(WM_FAN_MODE, WM_SET, (m & 0xfffffff0) | value);
311 	kfree(r);
312 
313 	return count;
314 }
315 
316 static ssize_t fan_mode_show(struct device *dev,
317 			     struct device_attribute *attr, char *buffer)
318 {
319 	unsigned int status;
320 	union acpi_object *r;
321 
322 	r = lg_wmab(WM_FAN_MODE, WM_GET, 0);
323 	if (!r)
324 		return -EIO;
325 
326 	if (r->type != ACPI_TYPE_INTEGER) {
327 		kfree(r);
328 		return -EIO;
329 	}
330 
331 	status = r->integer.value & 0x01;
332 	kfree(r);
333 
334 	return snprintf(buffer, PAGE_SIZE, "%d\n", status);
335 }
336 
337 static ssize_t usb_charge_store(struct device *dev,
338 				struct device_attribute *attr,
339 				const char *buffer, size_t count)
340 {
341 	bool value;
342 	union acpi_object *r;
343 	int ret;
344 
345 	ret = kstrtobool(buffer, &value);
346 	if (ret)
347 		return ret;
348 
349 	r = lg_wmbb(WMBB_USB_CHARGE, WM_SET, value);
350 	if (!r)
351 		return -EIO;
352 
353 	kfree(r);
354 	return count;
355 }
356 
357 static ssize_t usb_charge_show(struct device *dev,
358 			       struct device_attribute *attr, char *buffer)
359 {
360 	unsigned int status;
361 	union acpi_object *r;
362 
363 	r = lg_wmbb(WMBB_USB_CHARGE, WM_GET, 0);
364 	if (!r)
365 		return -EIO;
366 
367 	if (r->type != ACPI_TYPE_BUFFER) {
368 		kfree(r);
369 		return -EIO;
370 	}
371 
372 	status = !!r->buffer.pointer[0x10];
373 
374 	kfree(r);
375 
376 	return snprintf(buffer, PAGE_SIZE, "%d\n", status);
377 }
378 
379 static ssize_t reader_mode_store(struct device *dev,
380 				 struct device_attribute *attr,
381 				 const char *buffer, size_t count)
382 {
383 	bool value;
384 	union acpi_object *r;
385 	int ret;
386 
387 	ret = kstrtobool(buffer, &value);
388 	if (ret)
389 		return ret;
390 
391 	r = lg_wmab(WM_READER_MODE, WM_SET, value);
392 	if (!r)
393 		return -EIO;
394 
395 	kfree(r);
396 	return count;
397 }
398 
399 static ssize_t reader_mode_show(struct device *dev,
400 				struct device_attribute *attr, char *buffer)
401 {
402 	unsigned int status;
403 	union acpi_object *r;
404 
405 	r = lg_wmab(WM_READER_MODE, WM_GET, 0);
406 	if (!r)
407 		return -EIO;
408 
409 	if (r->type != ACPI_TYPE_INTEGER) {
410 		kfree(r);
411 		return -EIO;
412 	}
413 
414 	status = !!r->integer.value;
415 
416 	kfree(r);
417 
418 	return snprintf(buffer, PAGE_SIZE, "%d\n", status);
419 }
420 
421 static ssize_t fn_lock_store(struct device *dev,
422 			     struct device_attribute *attr,
423 			     const char *buffer, size_t count)
424 {
425 	bool value;
426 	union acpi_object *r;
427 	int ret;
428 
429 	ret = kstrtobool(buffer, &value);
430 	if (ret)
431 		return ret;
432 
433 	r = lg_wmab(WM_FN_LOCK, WM_SET, value);
434 	if (!r)
435 		return -EIO;
436 
437 	kfree(r);
438 	return count;
439 }
440 
441 static ssize_t fn_lock_show(struct device *dev,
442 			    struct device_attribute *attr, char *buffer)
443 {
444 	unsigned int status;
445 	union acpi_object *r;
446 
447 	r = lg_wmab(WM_FN_LOCK, WM_GET, 0);
448 	if (!r)
449 		return -EIO;
450 
451 	if (r->type != ACPI_TYPE_BUFFER) {
452 		kfree(r);
453 		return -EIO;
454 	}
455 
456 	status = !!r->buffer.pointer[0];
457 	kfree(r);
458 
459 	return snprintf(buffer, PAGE_SIZE, "%d\n", status);
460 }
461 
462 static ssize_t battery_care_limit_store(struct device *dev,
463 					struct device_attribute *attr,
464 					const char *buffer, size_t count)
465 {
466 	unsigned long value;
467 	int ret;
468 
469 	ret = kstrtoul(buffer, 10, &value);
470 	if (ret)
471 		return ret;
472 
473 	if (value == 100 || value == 80) {
474 		union acpi_object *r;
475 
476 		if (battery_limit_use_wmbb)
477 			r = lg_wmbb(WMBB_BATT_LIMIT, WM_SET, value);
478 		else
479 			r = lg_wmab(WM_BATT_LIMIT, WM_SET, value);
480 		if (!r)
481 			return -EIO;
482 
483 		kfree(r);
484 		return count;
485 	}
486 
487 	return -EINVAL;
488 }
489 
490 static ssize_t battery_care_limit_show(struct device *dev,
491 				       struct device_attribute *attr,
492 				       char *buffer)
493 {
494 	unsigned int status;
495 	union acpi_object *r;
496 
497 	if (battery_limit_use_wmbb) {
498 		r = lg_wmbb(WMBB_BATT_LIMIT, WM_GET, 0);
499 		if (!r)
500 			return -EIO;
501 
502 		if (r->type != ACPI_TYPE_BUFFER) {
503 			kfree(r);
504 			return -EIO;
505 		}
506 
507 		status = r->buffer.pointer[0x10];
508 	} else {
509 		r = lg_wmab(WM_BATT_LIMIT, WM_GET, 0);
510 		if (!r)
511 			return -EIO;
512 
513 		if (r->type != ACPI_TYPE_INTEGER) {
514 			kfree(r);
515 			return -EIO;
516 		}
517 
518 		status = r->integer.value;
519 	}
520 	kfree(r);
521 	if (status != 80 && status != 100)
522 		status = 0;
523 
524 	return snprintf(buffer, PAGE_SIZE, "%d\n", status);
525 }
526 
527 static DEVICE_ATTR_RW(fan_mode);
528 static DEVICE_ATTR_RW(usb_charge);
529 static DEVICE_ATTR_RW(reader_mode);
530 static DEVICE_ATTR_RW(fn_lock);
531 static DEVICE_ATTR_RW(battery_care_limit);
532 
533 static struct attribute *dev_attributes[] = {
534 	&dev_attr_fan_mode.attr,
535 	&dev_attr_usb_charge.attr,
536 	&dev_attr_reader_mode.attr,
537 	&dev_attr_fn_lock.attr,
538 	&dev_attr_battery_care_limit.attr,
539 	NULL
540 };
541 
542 static const struct attribute_group dev_attribute_group = {
543 	.attrs = dev_attributes,
544 };
545 
546 static void tpad_led_set(struct led_classdev *cdev,
547 			 enum led_brightness brightness)
548 {
549 	union acpi_object *r;
550 
551 	r = lg_wmab(WM_TLED, WM_SET, brightness > LED_OFF);
552 	kfree(r);
553 }
554 
555 static enum led_brightness tpad_led_get(struct led_classdev *cdev)
556 {
557 	return ggov(GOV_TLED) > 0 ? LED_ON : LED_OFF;
558 }
559 
560 static LED_DEVICE(tpad_led, 1, 0);
561 
562 static void kbd_backlight_set(struct led_classdev *cdev,
563 			      enum led_brightness brightness)
564 {
565 	u32 val;
566 	union acpi_object *r;
567 
568 	val = 0x22;
569 	if (brightness <= LED_OFF)
570 		val = 0;
571 	if (brightness >= LED_FULL)
572 		val = 0x24;
573 	r = lg_wmab(WM_KEY_LIGHT, WM_SET, val);
574 	kfree(r);
575 }
576 
577 static enum led_brightness get_kbd_backlight_level(void)
578 {
579 	union acpi_object *r;
580 	int val;
581 
582 	r = lg_wmab(WM_KEY_LIGHT, WM_GET, 0);
583 
584 	if (!r)
585 		return LED_OFF;
586 
587 	if (r->type != ACPI_TYPE_BUFFER || r->buffer.pointer[1] != 0x05) {
588 		kfree(r);
589 		return LED_OFF;
590 	}
591 
592 	switch (r->buffer.pointer[0] & 0x27) {
593 	case 0x24:
594 		val = LED_FULL;
595 		break;
596 	case 0x22:
597 		val = LED_HALF;
598 		break;
599 	default:
600 		val = LED_OFF;
601 	}
602 
603 	kfree(r);
604 
605 	return val;
606 }
607 
608 static enum led_brightness kbd_backlight_get(struct led_classdev *cdev)
609 {
610 	return get_kbd_backlight_level();
611 }
612 
613 static LED_DEVICE(kbd_backlight, 255, LED_BRIGHT_HW_CHANGED);
614 
615 static void wmi_input_destroy(void)
616 {
617 	if (inited & INIT_INPUT_WMI_2)
618 		wmi_remove_notify_handler(WMI_EVENT_GUID2);
619 
620 	if (inited & INIT_INPUT_WMI_0)
621 		wmi_remove_notify_handler(WMI_EVENT_GUID0);
622 
623 	if (inited & INIT_SPARSE_KEYMAP)
624 		input_unregister_device(wmi_input_dev);
625 
626 	inited &= ~(INIT_INPUT_WMI_0 | INIT_INPUT_WMI_2 | INIT_SPARSE_KEYMAP);
627 }
628 
629 static struct platform_driver pf_driver = {
630 	.driver = {
631 		   .name = PLATFORM_NAME,
632 	}
633 };
634 
635 static int acpi_add(struct acpi_device *device)
636 {
637 	int ret;
638 	const char *product;
639 	int year = 2017;
640 
641 	if (pf_device)
642 		return 0;
643 
644 	ret = platform_driver_register(&pf_driver);
645 	if (ret)
646 		return ret;
647 
648 	pf_device = platform_device_register_simple(PLATFORM_NAME,
649 						    PLATFORM_DEVID_NONE,
650 						    NULL, 0);
651 	if (IS_ERR(pf_device)) {
652 		ret = PTR_ERR(pf_device);
653 		pf_device = NULL;
654 		pr_err("unable to register platform device\n");
655 		goto out_platform_registered;
656 	}
657 	product = dmi_get_system_info(DMI_PRODUCT_NAME);
658 	if (product && strlen(product) > 4)
659 		switch (product[4]) {
660 		case '5':
661 		case '6':
662 			year = 2016;
663 			break;
664 		case '7':
665 			year = 2017;
666 			break;
667 		case '8':
668 			year = 2018;
669 			break;
670 		case '9':
671 			year = 2019;
672 			break;
673 		case '0':
674 			if (strlen(product) > 5)
675 				switch (product[5]) {
676 				case 'N':
677 					year = 2020;
678 					break;
679 				case 'P':
680 					year = 2021;
681 					break;
682 				default:
683 					year = 2022;
684 				}
685 			break;
686 		default:
687 			year = 2019;
688 		}
689 	pr_info("product: %s  year: %d\n", product, year);
690 
691 	if (year >= 2019)
692 		battery_limit_use_wmbb = 1;
693 
694 	ret = sysfs_create_group(&pf_device->dev.kobj, &dev_attribute_group);
695 	if (ret)
696 		goto out_platform_device;
697 
698 	/* LEDs are optional */
699 	led_classdev_register(&pf_device->dev, &kbd_backlight);
700 	led_classdev_register(&pf_device->dev, &tpad_led);
701 
702 	wmi_input_setup();
703 
704 	return 0;
705 
706 out_platform_device:
707 	platform_device_unregister(pf_device);
708 out_platform_registered:
709 	platform_driver_unregister(&pf_driver);
710 	return ret;
711 }
712 
713 static int acpi_remove(struct acpi_device *device)
714 {
715 	sysfs_remove_group(&pf_device->dev.kobj, &dev_attribute_group);
716 
717 	led_classdev_unregister(&tpad_led);
718 	led_classdev_unregister(&kbd_backlight);
719 
720 	wmi_input_destroy();
721 	platform_device_unregister(pf_device);
722 	pf_device = NULL;
723 	platform_driver_unregister(&pf_driver);
724 
725 	return 0;
726 }
727 
728 static const struct acpi_device_id device_ids[] = {
729 	{"LGEX0815", 0},
730 	{"", 0}
731 };
732 MODULE_DEVICE_TABLE(acpi, device_ids);
733 
734 static struct acpi_driver acpi_driver = {
735 	.name = "LG Gram Laptop Support",
736 	.class = "lg-laptop",
737 	.ids = device_ids,
738 	.ops = {
739 		.add = acpi_add,
740 		.remove = acpi_remove,
741 		.notify = acpi_notify,
742 		},
743 	.owner = THIS_MODULE,
744 };
745 
746 static int __init acpi_init(void)
747 {
748 	int result;
749 
750 	result = acpi_bus_register_driver(&acpi_driver);
751 	if (result < 0) {
752 		pr_debug("Error registering driver\n");
753 		return -ENODEV;
754 	}
755 
756 	return 0;
757 }
758 
759 static void __exit acpi_exit(void)
760 {
761 	acpi_bus_unregister_driver(&acpi_driver);
762 }
763 
764 module_init(acpi_init);
765 module_exit(acpi_exit);
766