summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
blob: 57afad79f55d086b673cd6c61c688d532620a033 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
/*
 * Copyright 2012 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/power_supply.h>
#include <linux/pm_runtime.h>
#include <acpi/video.h>
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include "amdgpu.h"
#include "amdgpu_pm.h"
#include "amd_acpi.h"
#include "atom.h"

/* Call the ATIF method
 */
/**
 * amdgpu_atif_call - call an ATIF method
 *
 * @handle: acpi handle
 * @function: the ATIF function to execute
 * @params: ATIF function params
 *
 * Executes the requested ATIF function (all asics).
 * Returns a pointer to the acpi output buffer.
 */
static union acpi_object *amdgpu_atif_call(acpi_handle handle, int function,
		struct acpi_buffer *params)
{
	acpi_status status;
	union acpi_object atif_arg_elements[2];
	struct acpi_object_list atif_arg;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	atif_arg.count = 2;
	atif_arg.pointer = &atif_arg_elements[0];

	atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
	atif_arg_elements[0].integer.value = function;

	if (params) {
		atif_arg_elements[1].type = ACPI_TYPE_BUFFER;
		atif_arg_elements[1].buffer.length = params->length;
		atif_arg_elements[1].buffer.pointer = params->pointer;
	} else {
		/* We need a second fake parameter */
		atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
		atif_arg_elements[1].integer.value = 0;
	}

	status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);

	/* Fail only if calling the method fails and ATIF is supported */
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
				 acpi_format_exception(status));
		kfree(buffer.pointer);
		return NULL;
	}

	return buffer.pointer;
}

/**
 * amdgpu_atif_parse_notification - parse supported notifications
 *
 * @n: supported notifications struct
 * @mask: supported notifications mask from ATIF
 *
 * Use the supported notifications mask from ATIF function
 * ATIF_FUNCTION_VERIFY_INTERFACE to determine what notifications
 * are supported (all asics).
 */
static void amdgpu_atif_parse_notification(struct amdgpu_atif_notifications *n, u32 mask)
{
	n->display_switch = mask & ATIF_DISPLAY_SWITCH_REQUEST_SUPPORTED;
	n->expansion_mode_change = mask & ATIF_EXPANSION_MODE_CHANGE_REQUEST_SUPPORTED;
	n->thermal_state = mask & ATIF_THERMAL_STATE_CHANGE_REQUEST_SUPPORTED;
	n->forced_power_state = mask & ATIF_FORCED_POWER_STATE_CHANGE_REQUEST_SUPPORTED;
	n->system_power_state = mask & ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST_SUPPORTED;
	n->display_conf_change = mask & ATIF_DISPLAY_CONF_CHANGE_REQUEST_SUPPORTED;
	n->px_gfx_switch = mask & ATIF_PX_GFX_SWITCH_REQUEST_SUPPORTED;
	n->brightness_change = mask & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST_SUPPORTED;
	n->dgpu_display_event = mask & ATIF_DGPU_DISPLAY_EVENT_SUPPORTED;
}

/**
 * amdgpu_atif_parse_functions - parse supported functions
 *
 * @f: supported functions struct
 * @mask: supported functions mask from ATIF
 *
 * Use the supported functions mask from ATIF function
 * ATIF_FUNCTION_VERIFY_INTERFACE to determine what functions
 * are supported (all asics).
 */
static void amdgpu_atif_parse_functions(struct amdgpu_atif_functions *f, u32 mask)
{
	f->system_params = mask & ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED;
	f->sbios_requests = mask & ATIF_GET_SYSTEM_BIOS_REQUESTS_SUPPORTED;
	f->select_active_disp = mask & ATIF_SELECT_ACTIVE_DISPLAYS_SUPPORTED;
	f->lid_state = mask & ATIF_GET_LID_STATE_SUPPORTED;
	f->get_tv_standard = mask & ATIF_GET_TV_STANDARD_FROM_CMOS_SUPPORTED;
	f->set_tv_standard = mask & ATIF_SET_TV_STANDARD_IN_CMOS_SUPPORTED;
	f->get_panel_expansion_mode = mask & ATIF_GET_PANEL_EXPANSION_MODE_FROM_CMOS_SUPPORTED;
	f->set_panel_expansion_mode = mask & ATIF_SET_PANEL_EXPANSION_MODE_IN_CMOS_SUPPORTED;
	f->temperature_change = mask & ATIF_TEMPERATURE_CHANGE_NOTIFICATION_SUPPORTED;
	f->graphics_device_types = mask & ATIF_GET_GRAPHICS_DEVICE_TYPES_SUPPORTED;
}

/**
 * amdgpu_atif_verify_interface - verify ATIF
 *
 * @handle: acpi handle
 * @atif: amdgpu atif struct
 *
 * Execute the ATIF_FUNCTION_VERIFY_INTERFACE ATIF function
 * to initialize ATIF and determine what features are supported
 * (all asics).
 * returns 0 on success, error on failure.
 */
static int amdgpu_atif_verify_interface(acpi_handle handle,
		struct amdgpu_atif *atif)
{
	union acpi_object *info;
	struct atif_verify_interface output;
	size_t size;
	int err = 0;

	info = amdgpu_atif_call(handle, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
	if (!info)
		return -EIO;

	memset(&output, 0, sizeof(output));

	size = *(u16 *) info->buffer.pointer;
	if (size < 12) {
		DRM_INFO("ATIF buffer is too small: %zu\n", size);
		err = -EINVAL;
		goto out;
	}
	size = min(sizeof(output), size);

	memcpy(&output, info->buffer.pointer, size);

	/* TODO: check version? */
	DRM_DEBUG_DRIVER("ATIF version %u\n", output.version);

	amdgpu_atif_parse_notification(&atif->notifications, output.notification_mask);
	amdgpu_atif_parse_functions(&atif->functions, output.function_bits);

out:
	kfree(info);
	return err;
}

/**
 * amdgpu_atif_get_notification_params - determine notify configuration
 *
 * @handle: acpi handle
 * @n: atif notification configuration struct
 *
 * Execute the ATIF_FUNCTION_GET_SYSTEM_PARAMETERS ATIF function
 * to determine if a notifier is used and if so which one
 * (all asics).  This is either Notify(VGA, 0x81) or Notify(VGA, n)
 * where n is specified in the result if a notifier is used.
 * Returns 0 on success, error on failure.
 */
static int amdgpu_atif_get_notification_params(acpi_handle handle,
		struct amdgpu_atif_notification_cfg *n)
{
	union acpi_object *info;
	struct atif_system_params params;
	size_t size;
	int err = 0;

	info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS, NULL);
	if (!info) {
		err = -EIO;
		goto out;
	}

	size = *(u16 *) info->buffer.pointer;
	if (size < 10) {
		err = -EINVAL;
		goto out;
	}

	memset(&params, 0, sizeof(params));
	size = min(sizeof(params), size);
	memcpy(&params, info->buffer.pointer, size);

	DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
			params.flags, params.valid_mask);
	params.flags = params.flags & params.valid_mask;

	if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_NONE) {
		n->enabled = false;
		n->command_code = 0;
	} else if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_81) {
		n->enabled = true;
		n->command_code = 0x81;
	} else {
		if (size < 11) {
			err = -EINVAL;
			goto out;
		}
		n->enabled = true;
		n->command_code = params.command_code;
	}

out:
	DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
			(n->enabled ? "enabled" : "disabled"),
			n->command_code);
	kfree(info);
	return err;
}

/**
 * amdgpu_atif_get_sbios_requests - get requested sbios event
 *
 * @handle: acpi handle
 * @req: atif sbios request struct
 *
 * Execute the ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS ATIF function
 * to determine what requests the sbios is making to the driver
 * (all asics).
 * Returns 0 on success, error on failure.
 */
static int amdgpu_atif_get_sbios_requests(acpi_handle handle,
		struct atif_sbios_requests *req)
{
	union acpi_object *info;
	size_t size;
	int count = 0;

	info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS, NULL);
	if (!info)
		return -EIO;

	size = *(u16 *)info->buffer.pointer;
	if (size < 0xd) {
		count = -EINVAL;
		goto out;
	}
	memset(req, 0, sizeof(*req));

	size = min(sizeof(*req), size);
	memcpy(req, info->buffer.pointer, size);
	DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);

	count = hweight32(req->pending);

out:
	kfree(info);
	return count;
}

/**
 * amdgpu_atif_handler - handle ATIF notify requests
 *
 * @adev: amdgpu_device pointer
 * @event: atif sbios request struct
 *
 * Checks the acpi event and if it matches an atif event,
 * handles it.
 * Returns NOTIFY code
 */
static int amdgpu_atif_handler(struct amdgpu_device *adev,
			struct acpi_bus_event *event)
{
	struct amdgpu_atif *atif = &adev->atif;
	struct atif_sbios_requests req;
	acpi_handle handle;
	int count;

	DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n",
			event->device_class, event->type);

	if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
		return NOTIFY_DONE;

	if (!atif->notification_cfg.enabled ||
	    event->type != atif->notification_cfg.command_code)
		/* Not our event */
		return NOTIFY_DONE;

	/* Check pending SBIOS requests */
	handle = ACPI_HANDLE(&adev->pdev->dev);
	count = amdgpu_atif_get_sbios_requests(handle, &req);

	if (count <= 0)
		return NOTIFY_DONE;

	DRM_DEBUG_DRIVER("ATIF: %d pending SBIOS requests\n", count);

	if (req.pending & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST) {
		struct amdgpu_encoder *enc = atif->encoder_for_bl;

		if (enc) {
			struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;

			DRM_DEBUG_DRIVER("Changing brightness to %d\n",
					req.backlight_level);

			amdgpu_display_backlight_set_level(adev, enc, req.backlight_level);

#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)
			backlight_force_update(dig->bl_dev,
					       BACKLIGHT_UPDATE_HOTKEY);
#endif
		}
	}
	if (req.pending & ATIF_DGPU_DISPLAY_EVENT) {
		if ((adev->flags & AMD_IS_PX) &&
		    amdgpu_atpx_dgpu_req_power_for_displays()) {
			pm_runtime_get_sync(adev->ddev->dev);
			/* Just fire off a uevent and let userspace tell us what to do */
			drm_helper_hpd_irq_event(adev->ddev);
			pm_runtime_mark_last_busy(adev->ddev->dev);
			pm_runtime_put_autosuspend(adev->ddev->dev);
		}
	}
	/* TODO: check other events */

	/* We've handled the event, stop the notifier chain. The ACPI interface
	 * overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
	 * userspace if the event was generated only to signal a SBIOS
	 * request.
	 */
	return NOTIFY_BAD;
}

/* Call the ATCS method
 */
/**
 * amdgpu_atcs_call - call an ATCS method
 *
 * @handle: acpi handle
 * @function: the ATCS function to execute
 * @params: ATCS function params
 *
 * Executes the requested ATCS function (all asics).
 * Returns a pointer to the acpi output buffer.
 */
static union acpi_object *amdgpu_atcs_call(acpi_handle handle, int function,
					   struct acpi_buffer *params)
{
	acpi_status status;
	union acpi_object atcs_arg_elements[2];
	struct acpi_object_list atcs_arg;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	atcs_arg.count = 2;
	atcs_arg.pointer = &atcs_arg_elements[0];

	atcs_arg_elements[0].type = ACPI_TYPE_INTEGER;
	atcs_arg_elements[0].integer.value = function;

	if (params) {
		atcs_arg_elements[1].type = ACPI_TYPE_BUFFER;
		atcs_arg_elements[1].buffer.length = params->length;
		atcs_arg_elements[1].buffer.pointer = params->pointer;
	} else {
		/* We need a second fake parameter */
		atcs_arg_elements[1].type = ACPI_TYPE_INTEGER;
		atcs_arg_elements[1].integer.value = 0;
	}

	status = acpi_evaluate_object(handle, "ATCS", &atcs_arg, &buffer);

	/* Fail only if calling the method fails and ATIF is supported */
	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
		DRM_DEBUG_DRIVER("failed to evaluate ATCS got %s\n",
				 acpi_format_exception(status));
		kfree(buffer.pointer);
		return NULL;
	}

	return buffer.pointer;
}

/**
 * amdgpu_atcs_parse_functions - parse supported functions
 *
 * @f: supported functions struct
 * @mask: supported functions mask from ATCS
 *
 * Use the supported functions mask from ATCS function
 * ATCS_FUNCTION_VERIFY_INTERFACE to determine what functions
 * are supported (all asics).
 */
static void amdgpu_atcs_parse_functions(struct amdgpu_atcs_functions *f, u32 mask)
{
	f->get_ext_state = mask & ATCS_GET_EXTERNAL_STATE_SUPPORTED;
	f->pcie_perf_req = mask & ATCS_PCIE_PERFORMANCE_REQUEST_SUPPORTED;
	f->pcie_dev_rdy = mask & ATCS_PCIE_DEVICE_READY_NOTIFICATION_SUPPORTED;
	f->pcie_bus_width = mask & ATCS_SET_PCIE_BUS_WIDTH_SUPPORTED;
}

/**
 * amdgpu_atcs_verify_interface - verify ATCS
 *
 * @handle: acpi handle
 * @atcs: amdgpu atcs struct
 *
 * Execute the ATCS_FUNCTION_VERIFY_INTERFACE ATCS function
 * to initialize ATCS and determine what features are supported
 * (all asics).
 * returns 0 on success, error on failure.
 */
static int amdgpu_atcs_verify_interface(acpi_handle handle,
					struct amdgpu_atcs *atcs)
{
	union acpi_object *info;
	struct atcs_verify_interface output;
	size_t size;
	int err = 0;

	info = amdgpu_atcs_call(handle, ATCS_FUNCTION_VERIFY_INTERFACE, NULL);
	if (!info)
		return -EIO;

	memset(&output, 0, sizeof(output));

	size = *(u16 *) info->buffer.pointer;
	if (size < 8) {
		DRM_INFO("ATCS buffer is too small: %zu\n", size);
		err = -EINVAL;
		goto out;
	}
	size = min(sizeof(output), size);

	memcpy(&output, info->buffer.pointer, size);

	/* TODO: check version? */
	DRM_DEBUG_DRIVER("ATCS version %u\n", output.version);

	amdgpu_atcs_parse_functions(&atcs->functions, output.function_bits);

out:
	kfree(info);
	return err;
}

/**
 * amdgpu_acpi_is_pcie_performance_request_supported
 *
 * @adev: amdgpu_device pointer
 *
 * Check if the ATCS pcie_perf_req and pcie_dev_rdy methods
 * are supported (all asics).
 * returns true if supported, false if not.
 */
bool amdgpu_acpi_is_pcie_performance_request_supported(struct amdgpu_device *adev)
{
	struct amdgpu_atcs *atcs = &adev->atcs;

	if (atcs->functions.pcie_perf_req && atcs->functions.pcie_dev_rdy)
		return true;

	return false;
}

/**
 * amdgpu_acpi_pcie_notify_device_ready
 *
 * @adev: amdgpu_device pointer
 *
 * Executes the PCIE_DEVICE_READY_NOTIFICATION method
 * (all asics).
 * returns 0 on success, error on failure.
 */
int amdgpu_acpi_pcie_notify_device_ready(struct amdgpu_device *adev)
{
	acpi_handle handle;
	union acpi_object *info;
	struct amdgpu_atcs *atcs = &adev->atcs;

	/* Get the device handle */
	handle = ACPI_HANDLE(&adev->pdev->dev);
	if (!handle)
		return -EINVAL;

	if (!atcs->functions.pcie_dev_rdy)
		return -EINVAL;

	info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_DEVICE_READY_NOTIFICATION, NULL);
	if (!info)
		return -EIO;

	kfree(info);

	return 0;
}

/**
 * amdgpu_acpi_pcie_performance_request
 *
 * @adev: amdgpu_device pointer
 * @perf_req: requested perf level (pcie gen speed)
 * @advertise: set advertise caps flag if set
 *
 * Executes the PCIE_PERFORMANCE_REQUEST method to
 * change the pcie gen speed (all asics).
 * returns 0 on success, error on failure.
 */
int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev,
					 u8 perf_req, bool advertise)
{
	acpi_handle handle;
	union acpi_object *info;
	struct amdgpu_atcs *atcs = &adev->atcs;
	struct atcs_pref_req_input atcs_input;
	struct atcs_pref_req_output atcs_output;
	struct acpi_buffer params;
	size_t size;
	u32 retry = 3;

	/* Get the device handle */
	handle = ACPI_HANDLE(&adev->pdev->dev);
	if (!handle)
		return -EINVAL;

	if (!atcs->functions.pcie_perf_req)
		return -EINVAL;

	atcs_input.size = sizeof(struct atcs_pref_req_input);
	/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
	atcs_input.client_id = adev->pdev->devfn | (adev->pdev->bus->number << 8);
	atcs_input.valid_flags_mask = ATCS_VALID_FLAGS_MASK;
	atcs_input.flags = ATCS_WAIT_FOR_COMPLETION;
	if (advertise)
		atcs_input.flags |= ATCS_ADVERTISE_CAPS;
	atcs_input.req_type = ATCS_PCIE_LINK_SPEED;
	atcs_input.perf_req = perf_req;

	params.length = sizeof(struct atcs_pref_req_input);
	params.pointer = &atcs_input;

	while (retry--) {
		info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_PERFORMANCE_REQUEST, &params);
		if (!info)
			return -EIO;

		memset(&atcs_output, 0, sizeof(atcs_output));

		size = *(u16 *) info->buffer.pointer;
		if (size < 3) {
			DRM_INFO("ATCS buffer is too small: %zu\n", size);
			kfree(info);
			return -EINVAL;
		}
		size = min(sizeof(atcs_output), size);

		memcpy(&atcs_output, info->buffer.pointer, size);

		kfree(info);

		switch (atcs_output.ret_val) {
		case ATCS_REQUEST_REFUSED:
		default:
			return -EINVAL;
		case ATCS_REQUEST_COMPLETE:
			return 0;
		case ATCS_REQUEST_IN_PROGRESS:
			udelay(10);
			break;
		}
	}

	return 0;
}

/**
 * amdgpu_acpi_event - handle notify events
 *
 * @nb: notifier block
 * @val: val
 * @data: acpi event
 *
 * Calls relevant amdgpu functions in response to various
 * acpi events.
 * Returns NOTIFY code
 */
static int amdgpu_acpi_event(struct notifier_block *nb,
			     unsigned long val,
			     void *data)
{
	struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;

	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
		if (power_supply_is_system_supplied() > 0)
			DRM_DEBUG_DRIVER("pm: AC\n");
		else
			DRM_DEBUG_DRIVER("pm: DC\n");

		amdgpu_pm_acpi_event_handler(adev);
	}

	/* Check for pending SBIOS requests */
	return amdgpu_atif_handler(adev, entry);
}

/* Call all ACPI methods here */
/**
 * amdgpu_acpi_init - init driver acpi support
 *
 * @adev: amdgpu_device pointer
 *
 * Verifies the AMD ACPI interfaces and registers with the acpi
 * notifier chain (all asics).
 * Returns 0 on success, error on failure.
 */
int amdgpu_acpi_init(struct amdgpu_device *adev)
{
	acpi_handle handle;
	struct amdgpu_atif *atif = &adev->atif;
	struct amdgpu_atcs *atcs = &adev->atcs;
	int ret;

	/* Get the device handle */
	handle = ACPI_HANDLE(&adev->pdev->dev);

	if (!adev->bios || !handle)
		return 0;

	/* Call the ATCS method */
	ret = amdgpu_atcs_verify_interface(handle, atcs);
	if (ret) {
		DRM_DEBUG_DRIVER("Call to ATCS verify_interface failed: %d\n", ret);
	}

	/* Call the ATIF method */
	ret = amdgpu_atif_verify_interface(handle, atif);
	if (ret) {
		DRM_DEBUG_DRIVER("Call to ATIF verify_interface failed: %d\n", ret);
		goto out;
	}

	if (atif->notifications.brightness_change) {
		struct drm_encoder *tmp;

		/* Find the encoder controlling the brightness */
		list_for_each_entry(tmp, &adev->ddev->mode_config.encoder_list,
				head) {
			struct amdgpu_encoder *enc = to_amdgpu_encoder(tmp);

			if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
			    enc->enc_priv) {
				struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
				if (dig->bl_dev) {
					atif->encoder_for_bl = enc;
					break;
				}
			}
		}
	}

	if (atif->functions.sbios_requests && !atif->functions.system_params) {
		/* XXX check this workraround, if sbios request function is
		 * present we have to see how it's configured in the system
		 * params
		 */
		atif->functions.system_params = true;
	}

	if (atif->functions.system_params) {
		ret = amdgpu_atif_get_notification_params(handle,
				&atif->notification_cfg);
		if (ret) {
			DRM_DEBUG_DRIVER("Call to GET_SYSTEM_PARAMS failed: %d\n",
					ret);
			/* Disable notification */
			atif->notification_cfg.enabled = false;
		}
	}

out:
	adev->acpi_nb.notifier_call = amdgpu_acpi_event;
	register_acpi_notifier(&adev->acpi_nb);

	return ret;
}

/**
 * amdgpu_acpi_fini - tear down driver acpi support
 *
 * @adev: amdgpu_device pointer
 *
 * Unregisters with the acpi notifier chain (all asics).
 */
void amdgpu_acpi_fini(struct amdgpu_device *adev)
{
	unregister_acpi_notifier(&adev->acpi_nb);
}