1 /*
2  * Copyright 2012 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  */
23 
24 #include <linux/pci.h>
25 #include <linux/acpi.h>
26 #include <linux/slab.h>
27 #include <linux/power_supply.h>
28 #include <acpi/video.h>
29 #include <drm/drmP.h>
30 #include <drm/drm_crtc_helper.h>
31 #include "amdgpu.h"
32 #include "amdgpu_acpi.h"
33 #include "atom.h"
34 
35 #define ACPI_AC_CLASS           "ac_adapter"
36 
37 extern void amdgpu_pm_acpi_event_handler(struct amdgpu_device *adev);
38 
39 struct atif_verify_interface {
40 	u16 size;		/* structure size in bytes (includes size field) */
41 	u16 version;		/* version */
42 	u32 notification_mask;	/* supported notifications mask */
43 	u32 function_bits;	/* supported functions bit vector */
44 } __packed;
45 
46 struct atif_system_params {
47 	u16 size;		/* structure size in bytes (includes size field) */
48 	u32 valid_mask;		/* valid flags mask */
49 	u32 flags;		/* flags */
50 	u8 command_code;	/* notify command code */
51 } __packed;
52 
53 struct atif_sbios_requests {
54 	u16 size;		/* structure size in bytes (includes size field) */
55 	u32 pending;		/* pending sbios requests */
56 	u8 panel_exp_mode;	/* panel expansion mode */
57 	u8 thermal_gfx;		/* thermal state: target gfx controller */
58 	u8 thermal_state;	/* thermal state: state id (0: exit state, non-0: state) */
59 	u8 forced_power_gfx;	/* forced power state: target gfx controller */
60 	u8 forced_power_state;	/* forced power state: state id */
61 	u8 system_power_src;	/* system power source */
62 	u8 backlight_level;	/* panel backlight level (0-255) */
63 } __packed;
64 
65 #define ATIF_NOTIFY_MASK	0x3
66 #define ATIF_NOTIFY_NONE	0
67 #define ATIF_NOTIFY_81		1
68 #define ATIF_NOTIFY_N		2
69 
70 struct atcs_verify_interface {
71 	u16 size;		/* structure size in bytes (includes size field) */
72 	u16 version;		/* version */
73 	u32 function_bits;	/* supported functions bit vector */
74 } __packed;
75 
76 #define ATCS_VALID_FLAGS_MASK	0x3
77 
78 struct atcs_pref_req_input {
79 	u16 size;		/* structure size in bytes (includes size field) */
80 	u16 client_id;		/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
81 	u16 valid_flags_mask;	/* valid flags mask */
82 	u16 flags;		/* flags */
83 	u8 req_type;		/* request type */
84 	u8 perf_req;		/* performance request */
85 } __packed;
86 
87 struct atcs_pref_req_output {
88 	u16 size;		/* structure size in bytes (includes size field) */
89 	u8 ret_val;		/* return value */
90 } __packed;
91 
92 /* Call the ATIF method
93  */
94 /**
95  * amdgpu_atif_call - call an ATIF method
96  *
97  * @handle: acpi handle
98  * @function: the ATIF function to execute
99  * @params: ATIF function params
100  *
101  * Executes the requested ATIF function (all asics).
102  * Returns a pointer to the acpi output buffer.
103  */
104 static union acpi_object *amdgpu_atif_call(acpi_handle handle, int function,
105 		struct acpi_buffer *params)
106 {
107 	acpi_status status;
108 	union acpi_object atif_arg_elements[2];
109 	struct acpi_object_list atif_arg;
110 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
111 
112 	atif_arg.count = 2;
113 	atif_arg.pointer = &atif_arg_elements[0];
114 
115 	atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
116 	atif_arg_elements[0].integer.value = function;
117 
118 	if (params) {
119 		atif_arg_elements[1].type = ACPI_TYPE_BUFFER;
120 		atif_arg_elements[1].buffer.length = params->length;
121 		atif_arg_elements[1].buffer.pointer = params->pointer;
122 	} else {
123 		/* We need a second fake parameter */
124 		atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
125 		atif_arg_elements[1].integer.value = 0;
126 	}
127 
128 	status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);
129 
130 	/* Fail only if calling the method fails and ATIF is supported */
131 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
132 		DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
133 				 acpi_format_exception(status));
134 		kfree(buffer.pointer);
135 		return NULL;
136 	}
137 
138 	return buffer.pointer;
139 }
140 
141 /**
142  * amdgpu_atif_parse_notification - parse supported notifications
143  *
144  * @n: supported notifications struct
145  * @mask: supported notifications mask from ATIF
146  *
147  * Use the supported notifications mask from ATIF function
148  * ATIF_FUNCTION_VERIFY_INTERFACE to determine what notifications
149  * are supported (all asics).
150  */
151 static void amdgpu_atif_parse_notification(struct amdgpu_atif_notifications *n, u32 mask)
152 {
153 	n->display_switch = mask & ATIF_DISPLAY_SWITCH_REQUEST_SUPPORTED;
154 	n->expansion_mode_change = mask & ATIF_EXPANSION_MODE_CHANGE_REQUEST_SUPPORTED;
155 	n->thermal_state = mask & ATIF_THERMAL_STATE_CHANGE_REQUEST_SUPPORTED;
156 	n->forced_power_state = mask & ATIF_FORCED_POWER_STATE_CHANGE_REQUEST_SUPPORTED;
157 	n->system_power_state = mask & ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST_SUPPORTED;
158 	n->display_conf_change = mask & ATIF_DISPLAY_CONF_CHANGE_REQUEST_SUPPORTED;
159 	n->px_gfx_switch = mask & ATIF_PX_GFX_SWITCH_REQUEST_SUPPORTED;
160 	n->brightness_change = mask & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST_SUPPORTED;
161 	n->dgpu_display_event = mask & ATIF_DGPU_DISPLAY_EVENT_SUPPORTED;
162 }
163 
164 /**
165  * amdgpu_atif_parse_functions - parse supported functions
166  *
167  * @f: supported functions struct
168  * @mask: supported functions mask from ATIF
169  *
170  * Use the supported functions mask from ATIF function
171  * ATIF_FUNCTION_VERIFY_INTERFACE to determine what functions
172  * are supported (all asics).
173  */
174 static void amdgpu_atif_parse_functions(struct amdgpu_atif_functions *f, u32 mask)
175 {
176 	f->system_params = mask & ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED;
177 	f->sbios_requests = mask & ATIF_GET_SYSTEM_BIOS_REQUESTS_SUPPORTED;
178 	f->select_active_disp = mask & ATIF_SELECT_ACTIVE_DISPLAYS_SUPPORTED;
179 	f->lid_state = mask & ATIF_GET_LID_STATE_SUPPORTED;
180 	f->get_tv_standard = mask & ATIF_GET_TV_STANDARD_FROM_CMOS_SUPPORTED;
181 	f->set_tv_standard = mask & ATIF_SET_TV_STANDARD_IN_CMOS_SUPPORTED;
182 	f->get_panel_expansion_mode = mask & ATIF_GET_PANEL_EXPANSION_MODE_FROM_CMOS_SUPPORTED;
183 	f->set_panel_expansion_mode = mask & ATIF_SET_PANEL_EXPANSION_MODE_IN_CMOS_SUPPORTED;
184 	f->temperature_change = mask & ATIF_TEMPERATURE_CHANGE_NOTIFICATION_SUPPORTED;
185 	f->graphics_device_types = mask & ATIF_GET_GRAPHICS_DEVICE_TYPES_SUPPORTED;
186 }
187 
188 /**
189  * amdgpu_atif_verify_interface - verify ATIF
190  *
191  * @handle: acpi handle
192  * @atif: amdgpu atif struct
193  *
194  * Execute the ATIF_FUNCTION_VERIFY_INTERFACE ATIF function
195  * to initialize ATIF and determine what features are supported
196  * (all asics).
197  * returns 0 on success, error on failure.
198  */
199 static int amdgpu_atif_verify_interface(acpi_handle handle,
200 		struct amdgpu_atif *atif)
201 {
202 	union acpi_object *info;
203 	struct atif_verify_interface output;
204 	size_t size;
205 	int err = 0;
206 
207 	info = amdgpu_atif_call(handle, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
208 	if (!info)
209 		return -EIO;
210 
211 	memset(&output, 0, sizeof(output));
212 
213 	size = *(u16 *) info->buffer.pointer;
214 	if (size < 12) {
215 		DRM_INFO("ATIF buffer is too small: %zu\n", size);
216 		err = -EINVAL;
217 		goto out;
218 	}
219 	size = min(sizeof(output), size);
220 
221 	memcpy(&output, info->buffer.pointer, size);
222 
223 	/* TODO: check version? */
224 	DRM_DEBUG_DRIVER("ATIF version %u\n", output.version);
225 
226 	amdgpu_atif_parse_notification(&atif->notifications, output.notification_mask);
227 	amdgpu_atif_parse_functions(&atif->functions, output.function_bits);
228 
229 out:
230 	kfree(info);
231 	return err;
232 }
233 
234 /**
235  * amdgpu_atif_get_notification_params - determine notify configuration
236  *
237  * @handle: acpi handle
238  * @n: atif notification configuration struct
239  *
240  * Execute the ATIF_FUNCTION_GET_SYSTEM_PARAMETERS ATIF function
241  * to determine if a notifier is used and if so which one
242  * (all asics).  This is either Notify(VGA, 0x81) or Notify(VGA, n)
243  * where n is specified in the result if a notifier is used.
244  * Returns 0 on success, error on failure.
245  */
246 static int amdgpu_atif_get_notification_params(acpi_handle handle,
247 		struct amdgpu_atif_notification_cfg *n)
248 {
249 	union acpi_object *info;
250 	struct atif_system_params params;
251 	size_t size;
252 	int err = 0;
253 
254 	info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS, NULL);
255 	if (!info) {
256 		err = -EIO;
257 		goto out;
258 	}
259 
260 	size = *(u16 *) info->buffer.pointer;
261 	if (size < 10) {
262 		err = -EINVAL;
263 		goto out;
264 	}
265 
266 	memset(&params, 0, sizeof(params));
267 	size = min(sizeof(params), size);
268 	memcpy(&params, info->buffer.pointer, size);
269 
270 	DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
271 			params.flags, params.valid_mask);
272 	params.flags = params.flags & params.valid_mask;
273 
274 	if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_NONE) {
275 		n->enabled = false;
276 		n->command_code = 0;
277 	} else if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_81) {
278 		n->enabled = true;
279 		n->command_code = 0x81;
280 	} else {
281 		if (size < 11) {
282 			err = -EINVAL;
283 			goto out;
284 		}
285 		n->enabled = true;
286 		n->command_code = params.command_code;
287 	}
288 
289 out:
290 	DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
291 			(n->enabled ? "enabled" : "disabled"),
292 			n->command_code);
293 	kfree(info);
294 	return err;
295 }
296 
297 /**
298  * amdgpu_atif_get_sbios_requests - get requested sbios event
299  *
300  * @handle: acpi handle
301  * @req: atif sbios request struct
302  *
303  * Execute the ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS ATIF function
304  * to determine what requests the sbios is making to the driver
305  * (all asics).
306  * Returns 0 on success, error on failure.
307  */
308 static int amdgpu_atif_get_sbios_requests(acpi_handle handle,
309 		struct atif_sbios_requests *req)
310 {
311 	union acpi_object *info;
312 	size_t size;
313 	int count = 0;
314 
315 	info = amdgpu_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS, NULL);
316 	if (!info)
317 		return -EIO;
318 
319 	size = *(u16 *)info->buffer.pointer;
320 	if (size < 0xd) {
321 		count = -EINVAL;
322 		goto out;
323 	}
324 	memset(req, 0, sizeof(*req));
325 
326 	size = min(sizeof(*req), size);
327 	memcpy(req, info->buffer.pointer, size);
328 	DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);
329 
330 	count = hweight32(req->pending);
331 
332 out:
333 	kfree(info);
334 	return count;
335 }
336 
337 /**
338  * amdgpu_atif_handler - handle ATIF notify requests
339  *
340  * @adev: amdgpu_device pointer
341  * @event: atif sbios request struct
342  *
343  * Checks the acpi event and if it matches an atif event,
344  * handles it.
345  * Returns NOTIFY code
346  */
347 int amdgpu_atif_handler(struct amdgpu_device *adev,
348 			struct acpi_bus_event *event)
349 {
350 	struct amdgpu_atif *atif = &adev->atif;
351 	struct atif_sbios_requests req;
352 	acpi_handle handle;
353 	int count;
354 
355 	DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n",
356 			event->device_class, event->type);
357 
358 	if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
359 		return NOTIFY_DONE;
360 
361 	if (!atif->notification_cfg.enabled ||
362 	    event->type != atif->notification_cfg.command_code)
363 		/* Not our event */
364 		return NOTIFY_DONE;
365 
366 	/* Check pending SBIOS requests */
367 	handle = ACPI_HANDLE(&adev->pdev->dev);
368 	count = amdgpu_atif_get_sbios_requests(handle, &req);
369 
370 	if (count <= 0)
371 		return NOTIFY_DONE;
372 
373 	DRM_DEBUG_DRIVER("ATIF: %d pending SBIOS requests\n", count);
374 
375 	if (req.pending & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST) {
376 		struct amdgpu_encoder *enc = atif->encoder_for_bl;
377 
378 		if (enc) {
379 			struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
380 
381 			DRM_DEBUG_DRIVER("Changing brightness to %d\n",
382 					req.backlight_level);
383 
384 			amdgpu_display_backlight_set_level(adev, enc, req.backlight_level);
385 
386 #if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)
387 			backlight_force_update(dig->bl_dev,
388 					       BACKLIGHT_UPDATE_HOTKEY);
389 #endif
390 		}
391 	}
392 	/* TODO: check other events */
393 
394 	/* We've handled the event, stop the notifier chain. The ACPI interface
395 	 * overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
396 	 * userspace if the event was generated only to signal a SBIOS
397 	 * request.
398 	 */
399 	return NOTIFY_BAD;
400 }
401 
402 /* Call the ATCS method
403  */
404 /**
405  * amdgpu_atcs_call - call an ATCS method
406  *
407  * @handle: acpi handle
408  * @function: the ATCS function to execute
409  * @params: ATCS function params
410  *
411  * Executes the requested ATCS function (all asics).
412  * Returns a pointer to the acpi output buffer.
413  */
414 static union acpi_object *amdgpu_atcs_call(acpi_handle handle, int function,
415 					   struct acpi_buffer *params)
416 {
417 	acpi_status status;
418 	union acpi_object atcs_arg_elements[2];
419 	struct acpi_object_list atcs_arg;
420 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
421 
422 	atcs_arg.count = 2;
423 	atcs_arg.pointer = &atcs_arg_elements[0];
424 
425 	atcs_arg_elements[0].type = ACPI_TYPE_INTEGER;
426 	atcs_arg_elements[0].integer.value = function;
427 
428 	if (params) {
429 		atcs_arg_elements[1].type = ACPI_TYPE_BUFFER;
430 		atcs_arg_elements[1].buffer.length = params->length;
431 		atcs_arg_elements[1].buffer.pointer = params->pointer;
432 	} else {
433 		/* We need a second fake parameter */
434 		atcs_arg_elements[1].type = ACPI_TYPE_INTEGER;
435 		atcs_arg_elements[1].integer.value = 0;
436 	}
437 
438 	status = acpi_evaluate_object(handle, "ATCS", &atcs_arg, &buffer);
439 
440 	/* Fail only if calling the method fails and ATIF is supported */
441 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
442 		DRM_DEBUG_DRIVER("failed to evaluate ATCS got %s\n",
443 				 acpi_format_exception(status));
444 		kfree(buffer.pointer);
445 		return NULL;
446 	}
447 
448 	return buffer.pointer;
449 }
450 
451 /**
452  * amdgpu_atcs_parse_functions - parse supported functions
453  *
454  * @f: supported functions struct
455  * @mask: supported functions mask from ATCS
456  *
457  * Use the supported functions mask from ATCS function
458  * ATCS_FUNCTION_VERIFY_INTERFACE to determine what functions
459  * are supported (all asics).
460  */
461 static void amdgpu_atcs_parse_functions(struct amdgpu_atcs_functions *f, u32 mask)
462 {
463 	f->get_ext_state = mask & ATCS_GET_EXTERNAL_STATE_SUPPORTED;
464 	f->pcie_perf_req = mask & ATCS_PCIE_PERFORMANCE_REQUEST_SUPPORTED;
465 	f->pcie_dev_rdy = mask & ATCS_PCIE_DEVICE_READY_NOTIFICATION_SUPPORTED;
466 	f->pcie_bus_width = mask & ATCS_SET_PCIE_BUS_WIDTH_SUPPORTED;
467 }
468 
469 /**
470  * amdgpu_atcs_verify_interface - verify ATCS
471  *
472  * @handle: acpi handle
473  * @atcs: amdgpu atcs struct
474  *
475  * Execute the ATCS_FUNCTION_VERIFY_INTERFACE ATCS function
476  * to initialize ATCS and determine what features are supported
477  * (all asics).
478  * returns 0 on success, error on failure.
479  */
480 static int amdgpu_atcs_verify_interface(acpi_handle handle,
481 					struct amdgpu_atcs *atcs)
482 {
483 	union acpi_object *info;
484 	struct atcs_verify_interface output;
485 	size_t size;
486 	int err = 0;
487 
488 	info = amdgpu_atcs_call(handle, ATCS_FUNCTION_VERIFY_INTERFACE, NULL);
489 	if (!info)
490 		return -EIO;
491 
492 	memset(&output, 0, sizeof(output));
493 
494 	size = *(u16 *) info->buffer.pointer;
495 	if (size < 8) {
496 		DRM_INFO("ATCS buffer is too small: %zu\n", size);
497 		err = -EINVAL;
498 		goto out;
499 	}
500 	size = min(sizeof(output), size);
501 
502 	memcpy(&output, info->buffer.pointer, size);
503 
504 	/* TODO: check version? */
505 	DRM_DEBUG_DRIVER("ATCS version %u\n", output.version);
506 
507 	amdgpu_atcs_parse_functions(&atcs->functions, output.function_bits);
508 
509 out:
510 	kfree(info);
511 	return err;
512 }
513 
514 /**
515  * amdgpu_acpi_is_pcie_performance_request_supported
516  *
517  * @adev: amdgpu_device pointer
518  *
519  * Check if the ATCS pcie_perf_req and pcie_dev_rdy methods
520  * are supported (all asics).
521  * returns true if supported, false if not.
522  */
523 bool amdgpu_acpi_is_pcie_performance_request_supported(struct amdgpu_device *adev)
524 {
525 	struct amdgpu_atcs *atcs = &adev->atcs;
526 
527 	if (atcs->functions.pcie_perf_req && atcs->functions.pcie_dev_rdy)
528 		return true;
529 
530 	return false;
531 }
532 
533 /**
534  * amdgpu_acpi_pcie_notify_device_ready
535  *
536  * @adev: amdgpu_device pointer
537  *
538  * Executes the PCIE_DEVICE_READY_NOTIFICATION method
539  * (all asics).
540  * returns 0 on success, error on failure.
541  */
542 int amdgpu_acpi_pcie_notify_device_ready(struct amdgpu_device *adev)
543 {
544 	acpi_handle handle;
545 	union acpi_object *info;
546 	struct amdgpu_atcs *atcs = &adev->atcs;
547 
548 	/* Get the device handle */
549 	handle = ACPI_HANDLE(&adev->pdev->dev);
550 	if (!handle)
551 		return -EINVAL;
552 
553 	if (!atcs->functions.pcie_dev_rdy)
554 		return -EINVAL;
555 
556 	info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_DEVICE_READY_NOTIFICATION, NULL);
557 	if (!info)
558 		return -EIO;
559 
560 	kfree(info);
561 
562 	return 0;
563 }
564 
565 /**
566  * amdgpu_acpi_pcie_performance_request
567  *
568  * @adev: amdgpu_device pointer
569  * @perf_req: requested perf level (pcie gen speed)
570  * @advertise: set advertise caps flag if set
571  *
572  * Executes the PCIE_PERFORMANCE_REQUEST method to
573  * change the pcie gen speed (all asics).
574  * returns 0 on success, error on failure.
575  */
576 int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev,
577 					 u8 perf_req, bool advertise)
578 {
579 	acpi_handle handle;
580 	union acpi_object *info;
581 	struct amdgpu_atcs *atcs = &adev->atcs;
582 	struct atcs_pref_req_input atcs_input;
583 	struct atcs_pref_req_output atcs_output;
584 	struct acpi_buffer params;
585 	size_t size;
586 	u32 retry = 3;
587 
588 	/* Get the device handle */
589 	handle = ACPI_HANDLE(&adev->pdev->dev);
590 	if (!handle)
591 		return -EINVAL;
592 
593 	if (!atcs->functions.pcie_perf_req)
594 		return -EINVAL;
595 
596 	atcs_input.size = sizeof(struct atcs_pref_req_input);
597 	/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
598 	atcs_input.client_id = adev->pdev->devfn | (adev->pdev->bus->number << 8);
599 	atcs_input.valid_flags_mask = ATCS_VALID_FLAGS_MASK;
600 	atcs_input.flags = ATCS_WAIT_FOR_COMPLETION;
601 	if (advertise)
602 		atcs_input.flags |= ATCS_ADVERTISE_CAPS;
603 	atcs_input.req_type = ATCS_PCIE_LINK_SPEED;
604 	atcs_input.perf_req = perf_req;
605 
606 	params.length = sizeof(struct atcs_pref_req_input);
607 	params.pointer = &atcs_input;
608 
609 	while (retry--) {
610 		info = amdgpu_atcs_call(handle, ATCS_FUNCTION_PCIE_PERFORMANCE_REQUEST, &params);
611 		if (!info)
612 			return -EIO;
613 
614 		memset(&atcs_output, 0, sizeof(atcs_output));
615 
616 		size = *(u16 *) info->buffer.pointer;
617 		if (size < 3) {
618 			DRM_INFO("ATCS buffer is too small: %zu\n", size);
619 			kfree(info);
620 			return -EINVAL;
621 		}
622 		size = min(sizeof(atcs_output), size);
623 
624 		memcpy(&atcs_output, info->buffer.pointer, size);
625 
626 		kfree(info);
627 
628 		switch (atcs_output.ret_val) {
629 		case ATCS_REQUEST_REFUSED:
630 		default:
631 			return -EINVAL;
632 		case ATCS_REQUEST_COMPLETE:
633 			return 0;
634 		case ATCS_REQUEST_IN_PROGRESS:
635 			udelay(10);
636 			break;
637 		}
638 	}
639 
640 	return 0;
641 }
642 
643 /**
644  * amdgpu_acpi_event - handle notify events
645  *
646  * @nb: notifier block
647  * @val: val
648  * @data: acpi event
649  *
650  * Calls relevant amdgpu functions in response to various
651  * acpi events.
652  * Returns NOTIFY code
653  */
654 static int amdgpu_acpi_event(struct notifier_block *nb,
655 			     unsigned long val,
656 			     void *data)
657 {
658 	struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
659 	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
660 
661 	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
662 		if (power_supply_is_system_supplied() > 0)
663 			DRM_DEBUG_DRIVER("pm: AC\n");
664 		else
665 			DRM_DEBUG_DRIVER("pm: DC\n");
666 
667 		amdgpu_pm_acpi_event_handler(adev);
668 	}
669 
670 	/* Check for pending SBIOS requests */
671 	return amdgpu_atif_handler(adev, entry);
672 }
673 
674 /* Call all ACPI methods here */
675 /**
676  * amdgpu_acpi_init - init driver acpi support
677  *
678  * @adev: amdgpu_device pointer
679  *
680  * Verifies the AMD ACPI interfaces and registers with the acpi
681  * notifier chain (all asics).
682  * Returns 0 on success, error on failure.
683  */
684 int amdgpu_acpi_init(struct amdgpu_device *adev)
685 {
686 	acpi_handle handle;
687 	struct amdgpu_atif *atif = &adev->atif;
688 	struct amdgpu_atcs *atcs = &adev->atcs;
689 	int ret;
690 
691 	/* Get the device handle */
692 	handle = ACPI_HANDLE(&adev->pdev->dev);
693 
694 	if (!adev->bios || !handle)
695 		return 0;
696 
697 	/* Call the ATCS method */
698 	ret = amdgpu_atcs_verify_interface(handle, atcs);
699 	if (ret) {
700 		DRM_DEBUG_DRIVER("Call to ATCS verify_interface failed: %d\n", ret);
701 	}
702 
703 	/* Call the ATIF method */
704 	ret = amdgpu_atif_verify_interface(handle, atif);
705 	if (ret) {
706 		DRM_DEBUG_DRIVER("Call to ATIF verify_interface failed: %d\n", ret);
707 		goto out;
708 	}
709 
710 	if (atif->notifications.brightness_change) {
711 		struct drm_encoder *tmp;
712 
713 		/* Find the encoder controlling the brightness */
714 		list_for_each_entry(tmp, &adev->ddev->mode_config.encoder_list,
715 				head) {
716 			struct amdgpu_encoder *enc = to_amdgpu_encoder(tmp);
717 
718 			if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
719 			    enc->enc_priv) {
720 				if (adev->is_atom_bios) {
721 					struct amdgpu_encoder_atom_dig *dig = enc->enc_priv;
722 					if (dig->bl_dev) {
723 						atif->encoder_for_bl = enc;
724 						break;
725 					}
726 				}
727 			}
728 		}
729 	}
730 
731 	if (atif->functions.sbios_requests && !atif->functions.system_params) {
732 		/* XXX check this workraround, if sbios request function is
733 		 * present we have to see how it's configured in the system
734 		 * params
735 		 */
736 		atif->functions.system_params = true;
737 	}
738 
739 	if (atif->functions.system_params) {
740 		ret = amdgpu_atif_get_notification_params(handle,
741 				&atif->notification_cfg);
742 		if (ret) {
743 			DRM_DEBUG_DRIVER("Call to GET_SYSTEM_PARAMS failed: %d\n",
744 					ret);
745 			/* Disable notification */
746 			atif->notification_cfg.enabled = false;
747 		}
748 	}
749 
750 out:
751 	adev->acpi_nb.notifier_call = amdgpu_acpi_event;
752 	register_acpi_notifier(&adev->acpi_nb);
753 
754 	return ret;
755 }
756 
757 /**
758  * amdgpu_acpi_fini - tear down driver acpi support
759  *
760  * @adev: amdgpu_device pointer
761  *
762  * Unregisters with the acpi notifier chain (all asics).
763  */
764 void amdgpu_acpi_fini(struct amdgpu_device *adev)
765 {
766 	unregister_acpi_notifier(&adev->acpi_nb);
767 }
768