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/acpi.h>
25 #include <linux/backlight.h>
26 #include <linux/pci.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/power_supply.h>
29 #include <linux/slab.h>
30 
31 #include <acpi/acpi_bus.h>
32 #include <acpi/video.h>
33 
34 #include <drm/drm_probe_helper.h>
35 
36 #include "atom.h"
37 #include "radeon.h"
38 #include "radeon_acpi.h"
39 #include "radeon_pm.h"
40 
41 #if defined(CONFIG_VGA_SWITCHEROO)
42 bool radeon_atpx_dgpu_req_power_for_displays(void);
43 #else
44 static inline bool radeon_atpx_dgpu_req_power_for_displays(void) { return false; }
45 #endif
46 
47 #define ACPI_AC_CLASS           "ac_adapter"
48 
49 struct atif_verify_interface {
50 	u16 size;		/* structure size in bytes (includes size field) */
51 	u16 version;		/* version */
52 	u32 notification_mask;	/* supported notifications mask */
53 	u32 function_bits;	/* supported functions bit vector */
54 } __packed;
55 
56 struct atif_system_params {
57 	u16 size;		/* structure size in bytes (includes size field) */
58 	u32 valid_mask;		/* valid flags mask */
59 	u32 flags;		/* flags */
60 	u8 command_code;	/* notify command code */
61 } __packed;
62 
63 struct atif_sbios_requests {
64 	u16 size;		/* structure size in bytes (includes size field) */
65 	u32 pending;		/* pending sbios requests */
66 	u8 panel_exp_mode;	/* panel expansion mode */
67 	u8 thermal_gfx;		/* thermal state: target gfx controller */
68 	u8 thermal_state;	/* thermal state: state id (0: exit state, non-0: state) */
69 	u8 forced_power_gfx;	/* forced power state: target gfx controller */
70 	u8 forced_power_state;	/* forced power state: state id */
71 	u8 system_power_src;	/* system power source */
72 	u8 backlight_level;	/* panel backlight level (0-255) */
73 } __packed;
74 
75 #define ATIF_NOTIFY_MASK	0x3
76 #define ATIF_NOTIFY_NONE	0
77 #define ATIF_NOTIFY_81		1
78 #define ATIF_NOTIFY_N		2
79 
80 struct atcs_verify_interface {
81 	u16 size;		/* structure size in bytes (includes size field) */
82 	u16 version;		/* version */
83 	u32 function_bits;	/* supported functions bit vector */
84 } __packed;
85 
86 #define ATCS_VALID_FLAGS_MASK	0x3
87 
88 struct atcs_pref_req_input {
89 	u16 size;		/* structure size in bytes (includes size field) */
90 	u16 client_id;		/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
91 	u16 valid_flags_mask;	/* valid flags mask */
92 	u16 flags;		/* flags */
93 	u8 req_type;		/* request type */
94 	u8 perf_req;		/* performance request */
95 } __packed;
96 
97 struct atcs_pref_req_output {
98 	u16 size;		/* structure size in bytes (includes size field) */
99 	u8 ret_val;		/* return value */
100 } __packed;
101 
102 /* Call the ATIF method
103  */
104 /**
105  * radeon_atif_call - call an ATIF method
106  *
107  * @handle: acpi handle
108  * @function: the ATIF function to execute
109  * @params: ATIF function params
110  *
111  * Executes the requested ATIF function (all asics).
112  * Returns a pointer to the acpi output buffer.
113  */
114 static union acpi_object *radeon_atif_call(acpi_handle handle, int function,
115 		struct acpi_buffer *params)
116 {
117 	acpi_status status;
118 	union acpi_object atif_arg_elements[2];
119 	struct acpi_object_list atif_arg;
120 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
121 
122 	atif_arg.count = 2;
123 	atif_arg.pointer = &atif_arg_elements[0];
124 
125 	atif_arg_elements[0].type = ACPI_TYPE_INTEGER;
126 	atif_arg_elements[0].integer.value = function;
127 
128 	if (params) {
129 		atif_arg_elements[1].type = ACPI_TYPE_BUFFER;
130 		atif_arg_elements[1].buffer.length = params->length;
131 		atif_arg_elements[1].buffer.pointer = params->pointer;
132 	} else {
133 		/* We need a second fake parameter */
134 		atif_arg_elements[1].type = ACPI_TYPE_INTEGER;
135 		atif_arg_elements[1].integer.value = 0;
136 	}
137 
138 	status = acpi_evaluate_object(handle, "ATIF", &atif_arg, &buffer);
139 
140 	/* Fail only if calling the method fails and ATIF is supported */
141 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
142 		DRM_DEBUG_DRIVER("failed to evaluate ATIF got %s\n",
143 				 acpi_format_exception(status));
144 		kfree(buffer.pointer);
145 		return NULL;
146 	}
147 
148 	return buffer.pointer;
149 }
150 
151 /**
152  * radeon_atif_parse_notification - parse supported notifications
153  *
154  * @n: supported notifications struct
155  * @mask: supported notifications mask from ATIF
156  *
157  * Use the supported notifications mask from ATIF function
158  * ATIF_FUNCTION_VERIFY_INTERFACE to determine what notifications
159  * are supported (all asics).
160  */
161 static void radeon_atif_parse_notification(struct radeon_atif_notifications *n, u32 mask)
162 {
163 	n->display_switch = mask & ATIF_DISPLAY_SWITCH_REQUEST_SUPPORTED;
164 	n->expansion_mode_change = mask & ATIF_EXPANSION_MODE_CHANGE_REQUEST_SUPPORTED;
165 	n->thermal_state = mask & ATIF_THERMAL_STATE_CHANGE_REQUEST_SUPPORTED;
166 	n->forced_power_state = mask & ATIF_FORCED_POWER_STATE_CHANGE_REQUEST_SUPPORTED;
167 	n->system_power_state = mask & ATIF_SYSTEM_POWER_SOURCE_CHANGE_REQUEST_SUPPORTED;
168 	n->display_conf_change = mask & ATIF_DISPLAY_CONF_CHANGE_REQUEST_SUPPORTED;
169 	n->px_gfx_switch = mask & ATIF_PX_GFX_SWITCH_REQUEST_SUPPORTED;
170 	n->brightness_change = mask & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST_SUPPORTED;
171 	n->dgpu_display_event = mask & ATIF_DGPU_DISPLAY_EVENT_SUPPORTED;
172 }
173 
174 /**
175  * radeon_atif_parse_functions - parse supported functions
176  *
177  * @f: supported functions struct
178  * @mask: supported functions mask from ATIF
179  *
180  * Use the supported functions mask from ATIF function
181  * ATIF_FUNCTION_VERIFY_INTERFACE to determine what functions
182  * are supported (all asics).
183  */
184 static void radeon_atif_parse_functions(struct radeon_atif_functions *f, u32 mask)
185 {
186 	f->system_params = mask & ATIF_GET_SYSTEM_PARAMETERS_SUPPORTED;
187 	f->sbios_requests = mask & ATIF_GET_SYSTEM_BIOS_REQUESTS_SUPPORTED;
188 	f->select_active_disp = mask & ATIF_SELECT_ACTIVE_DISPLAYS_SUPPORTED;
189 	f->lid_state = mask & ATIF_GET_LID_STATE_SUPPORTED;
190 	f->get_tv_standard = mask & ATIF_GET_TV_STANDARD_FROM_CMOS_SUPPORTED;
191 	f->set_tv_standard = mask & ATIF_SET_TV_STANDARD_IN_CMOS_SUPPORTED;
192 	f->get_panel_expansion_mode = mask & ATIF_GET_PANEL_EXPANSION_MODE_FROM_CMOS_SUPPORTED;
193 	f->set_panel_expansion_mode = mask & ATIF_SET_PANEL_EXPANSION_MODE_IN_CMOS_SUPPORTED;
194 	f->temperature_change = mask & ATIF_TEMPERATURE_CHANGE_NOTIFICATION_SUPPORTED;
195 	f->graphics_device_types = mask & ATIF_GET_GRAPHICS_DEVICE_TYPES_SUPPORTED;
196 }
197 
198 /**
199  * radeon_atif_verify_interface - verify ATIF
200  *
201  * @handle: acpi handle
202  * @atif: radeon atif struct
203  *
204  * Execute the ATIF_FUNCTION_VERIFY_INTERFACE ATIF function
205  * to initialize ATIF and determine what features are supported
206  * (all asics).
207  * returns 0 on success, error on failure.
208  */
209 static int radeon_atif_verify_interface(acpi_handle handle,
210 		struct radeon_atif *atif)
211 {
212 	union acpi_object *info;
213 	struct atif_verify_interface output;
214 	size_t size;
215 	int err = 0;
216 
217 	info = radeon_atif_call(handle, ATIF_FUNCTION_VERIFY_INTERFACE, NULL);
218 	if (!info)
219 		return -EIO;
220 
221 	memset(&output, 0, sizeof(output));
222 
223 	size = *(u16 *) info->buffer.pointer;
224 	if (size < 12) {
225 		DRM_INFO("ATIF buffer is too small: %zu\n", size);
226 		err = -EINVAL;
227 		goto out;
228 	}
229 	size = min(sizeof(output), size);
230 
231 	memcpy(&output, info->buffer.pointer, size);
232 
233 	/* TODO: check version? */
234 	DRM_DEBUG_DRIVER("ATIF version %u\n", output.version);
235 
236 	radeon_atif_parse_notification(&atif->notifications, output.notification_mask);
237 	radeon_atif_parse_functions(&atif->functions, output.function_bits);
238 
239 out:
240 	kfree(info);
241 	return err;
242 }
243 
244 /**
245  * radeon_atif_get_notification_params - determine notify configuration
246  *
247  * @handle: acpi handle
248  * @n: atif notification configuration struct
249  *
250  * Execute the ATIF_FUNCTION_GET_SYSTEM_PARAMETERS ATIF function
251  * to determine if a notifier is used and if so which one
252  * (all asics).  This is either Notify(VGA, 0x81) or Notify(VGA, n)
253  * where n is specified in the result if a notifier is used.
254  * Returns 0 on success, error on failure.
255  */
256 static int radeon_atif_get_notification_params(acpi_handle handle,
257 		struct radeon_atif_notification_cfg *n)
258 {
259 	union acpi_object *info;
260 	struct atif_system_params params;
261 	size_t size;
262 	int err = 0;
263 
264 	info = radeon_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_PARAMETERS, NULL);
265 	if (!info) {
266 		err = -EIO;
267 		goto out;
268 	}
269 
270 	size = *(u16 *) info->buffer.pointer;
271 	if (size < 10) {
272 		err = -EINVAL;
273 		goto out;
274 	}
275 
276 	memset(&params, 0, sizeof(params));
277 	size = min(sizeof(params), size);
278 	memcpy(&params, info->buffer.pointer, size);
279 
280 	DRM_DEBUG_DRIVER("SYSTEM_PARAMS: mask = %#x, flags = %#x\n",
281 			params.flags, params.valid_mask);
282 	params.flags = params.flags & params.valid_mask;
283 
284 	if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_NONE) {
285 		n->enabled = false;
286 		n->command_code = 0;
287 	} else if ((params.flags & ATIF_NOTIFY_MASK) == ATIF_NOTIFY_81) {
288 		n->enabled = true;
289 		n->command_code = 0x81;
290 	} else {
291 		if (size < 11) {
292 			err = -EINVAL;
293 			goto out;
294 		}
295 		n->enabled = true;
296 		n->command_code = params.command_code;
297 	}
298 
299 out:
300 	DRM_DEBUG_DRIVER("Notification %s, command code = %#x\n",
301 			(n->enabled ? "enabled" : "disabled"),
302 			n->command_code);
303 	kfree(info);
304 	return err;
305 }
306 
307 /**
308  * radeon_atif_get_sbios_requests - get requested sbios event
309  *
310  * @handle: acpi handle
311  * @req: atif sbios request struct
312  *
313  * Execute the ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS ATIF function
314  * to determine what requests the sbios is making to the driver
315  * (all asics).
316  * Returns 0 on success, error on failure.
317  */
318 static int radeon_atif_get_sbios_requests(acpi_handle handle,
319 		struct atif_sbios_requests *req)
320 {
321 	union acpi_object *info;
322 	size_t size;
323 	int count = 0;
324 
325 	info = radeon_atif_call(handle, ATIF_FUNCTION_GET_SYSTEM_BIOS_REQUESTS, NULL);
326 	if (!info)
327 		return -EIO;
328 
329 	size = *(u16 *)info->buffer.pointer;
330 	if (size < 0xd) {
331 		count = -EINVAL;
332 		goto out;
333 	}
334 	memset(req, 0, sizeof(*req));
335 
336 	size = min(sizeof(*req), size);
337 	memcpy(req, info->buffer.pointer, size);
338 	DRM_DEBUG_DRIVER("SBIOS pending requests: %#x\n", req->pending);
339 
340 	count = hweight32(req->pending);
341 
342 out:
343 	kfree(info);
344 	return count;
345 }
346 
347 /**
348  * radeon_atif_handler - handle ATIF notify requests
349  *
350  * @rdev: radeon_device pointer
351  * @event: atif sbios request struct
352  *
353  * Checks the acpi event and if it matches an atif event,
354  * handles it.
355  * Returns NOTIFY code
356  */
357 static int radeon_atif_handler(struct radeon_device *rdev,
358 		struct acpi_bus_event *event)
359 {
360 	struct radeon_atif *atif = &rdev->atif;
361 	struct atif_sbios_requests req;
362 	acpi_handle handle;
363 	int count;
364 
365 	DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n",
366 			event->device_class, event->type);
367 
368 	if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
369 		return NOTIFY_DONE;
370 
371 	if (!atif->notification_cfg.enabled ||
372 			event->type != atif->notification_cfg.command_code)
373 		/* Not our event */
374 		return NOTIFY_DONE;
375 
376 	/* Check pending SBIOS requests */
377 	handle = ACPI_HANDLE(&rdev->pdev->dev);
378 	count = radeon_atif_get_sbios_requests(handle, &req);
379 
380 	if (count <= 0)
381 		return NOTIFY_DONE;
382 
383 	DRM_DEBUG_DRIVER("ATIF: %d pending SBIOS requests\n", count);
384 
385 	if (req.pending & ATIF_PANEL_BRIGHTNESS_CHANGE_REQUEST) {
386 		struct radeon_encoder *enc = atif->encoder_for_bl;
387 
388 		if (enc) {
389 			DRM_DEBUG_DRIVER("Changing brightness to %d\n",
390 					req.backlight_level);
391 
392 			radeon_set_backlight_level(rdev, enc, req.backlight_level);
393 
394 			if (rdev->is_atom_bios) {
395 				struct radeon_encoder_atom_dig *dig = enc->enc_priv;
396 				backlight_force_update(dig->bl_dev,
397 						       BACKLIGHT_UPDATE_HOTKEY);
398 			} else {
399 				struct radeon_encoder_lvds *dig = enc->enc_priv;
400 				backlight_force_update(dig->bl_dev,
401 						       BACKLIGHT_UPDATE_HOTKEY);
402 			}
403 		}
404 	}
405 	if (req.pending & ATIF_DGPU_DISPLAY_EVENT) {
406 		if ((rdev->flags & RADEON_IS_PX) &&
407 		    radeon_atpx_dgpu_req_power_for_displays()) {
408 			pm_runtime_get_sync(rdev->ddev->dev);
409 			/* Just fire off a uevent and let userspace tell us what to do */
410 			drm_helper_hpd_irq_event(rdev->ddev);
411 			pm_runtime_mark_last_busy(rdev->ddev->dev);
412 			pm_runtime_put_autosuspend(rdev->ddev->dev);
413 		}
414 	}
415 	/* TODO: check other events */
416 
417 	/* We've handled the event, stop the notifier chain. The ACPI interface
418 	 * overloads ACPI_VIDEO_NOTIFY_PROBE, we don't want to send that to
419 	 * userspace if the event was generated only to signal a SBIOS
420 	 * request.
421 	 */
422 	return NOTIFY_BAD;
423 }
424 
425 /* Call the ATCS method
426  */
427 /**
428  * radeon_atcs_call - call an ATCS method
429  *
430  * @handle: acpi handle
431  * @function: the ATCS function to execute
432  * @params: ATCS function params
433  *
434  * Executes the requested ATCS function (all asics).
435  * Returns a pointer to the acpi output buffer.
436  */
437 static union acpi_object *radeon_atcs_call(acpi_handle handle, int function,
438 					   struct acpi_buffer *params)
439 {
440 	acpi_status status;
441 	union acpi_object atcs_arg_elements[2];
442 	struct acpi_object_list atcs_arg;
443 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
444 
445 	atcs_arg.count = 2;
446 	atcs_arg.pointer = &atcs_arg_elements[0];
447 
448 	atcs_arg_elements[0].type = ACPI_TYPE_INTEGER;
449 	atcs_arg_elements[0].integer.value = function;
450 
451 	if (params) {
452 		atcs_arg_elements[1].type = ACPI_TYPE_BUFFER;
453 		atcs_arg_elements[1].buffer.length = params->length;
454 		atcs_arg_elements[1].buffer.pointer = params->pointer;
455 	} else {
456 		/* We need a second fake parameter */
457 		atcs_arg_elements[1].type = ACPI_TYPE_INTEGER;
458 		atcs_arg_elements[1].integer.value = 0;
459 	}
460 
461 	status = acpi_evaluate_object(handle, "ATCS", &atcs_arg, &buffer);
462 
463 	/* Fail only if calling the method fails and ATIF is supported */
464 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
465 		DRM_DEBUG_DRIVER("failed to evaluate ATCS got %s\n",
466 				 acpi_format_exception(status));
467 		kfree(buffer.pointer);
468 		return NULL;
469 	}
470 
471 	return buffer.pointer;
472 }
473 
474 /**
475  * radeon_atcs_parse_functions - parse supported functions
476  *
477  * @f: supported functions struct
478  * @mask: supported functions mask from ATCS
479  *
480  * Use the supported functions mask from ATCS function
481  * ATCS_FUNCTION_VERIFY_INTERFACE to determine what functions
482  * are supported (all asics).
483  */
484 static void radeon_atcs_parse_functions(struct radeon_atcs_functions *f, u32 mask)
485 {
486 	f->get_ext_state = mask & ATCS_GET_EXTERNAL_STATE_SUPPORTED;
487 	f->pcie_perf_req = mask & ATCS_PCIE_PERFORMANCE_REQUEST_SUPPORTED;
488 	f->pcie_dev_rdy = mask & ATCS_PCIE_DEVICE_READY_NOTIFICATION_SUPPORTED;
489 	f->pcie_bus_width = mask & ATCS_SET_PCIE_BUS_WIDTH_SUPPORTED;
490 }
491 
492 /**
493  * radeon_atcs_verify_interface - verify ATCS
494  *
495  * @handle: acpi handle
496  * @atcs: radeon atcs struct
497  *
498  * Execute the ATCS_FUNCTION_VERIFY_INTERFACE ATCS function
499  * to initialize ATCS and determine what features are supported
500  * (all asics).
501  * returns 0 on success, error on failure.
502  */
503 static int radeon_atcs_verify_interface(acpi_handle handle,
504 					struct radeon_atcs *atcs)
505 {
506 	union acpi_object *info;
507 	struct atcs_verify_interface output;
508 	size_t size;
509 	int err = 0;
510 
511 	info = radeon_atcs_call(handle, ATCS_FUNCTION_VERIFY_INTERFACE, NULL);
512 	if (!info)
513 		return -EIO;
514 
515 	memset(&output, 0, sizeof(output));
516 
517 	size = *(u16 *) info->buffer.pointer;
518 	if (size < 8) {
519 		DRM_INFO("ATCS buffer is too small: %zu\n", size);
520 		err = -EINVAL;
521 		goto out;
522 	}
523 	size = min(sizeof(output), size);
524 
525 	memcpy(&output, info->buffer.pointer, size);
526 
527 	/* TODO: check version? */
528 	DRM_DEBUG_DRIVER("ATCS version %u\n", output.version);
529 
530 	radeon_atcs_parse_functions(&atcs->functions, output.function_bits);
531 
532 out:
533 	kfree(info);
534 	return err;
535 }
536 
537 /**
538  * radeon_acpi_is_pcie_performance_request_supported
539  *
540  * @rdev: radeon_device pointer
541  *
542  * Check if the ATCS pcie_perf_req and pcie_dev_rdy methods
543  * are supported (all asics).
544  * returns true if supported, false if not.
545  */
546 bool radeon_acpi_is_pcie_performance_request_supported(struct radeon_device *rdev)
547 {
548 	struct radeon_atcs *atcs = &rdev->atcs;
549 
550 	if (atcs->functions.pcie_perf_req && atcs->functions.pcie_dev_rdy)
551 		return true;
552 
553 	return false;
554 }
555 
556 /**
557  * radeon_acpi_pcie_notify_device_ready
558  *
559  * @rdev: radeon_device pointer
560  *
561  * Executes the PCIE_DEVICE_READY_NOTIFICATION method
562  * (all asics).
563  * returns 0 on success, error on failure.
564  */
565 int radeon_acpi_pcie_notify_device_ready(struct radeon_device *rdev)
566 {
567 	acpi_handle handle;
568 	union acpi_object *info;
569 	struct radeon_atcs *atcs = &rdev->atcs;
570 
571 	/* Get the device handle */
572 	handle = ACPI_HANDLE(&rdev->pdev->dev);
573 	if (!handle)
574 		return -EINVAL;
575 
576 	if (!atcs->functions.pcie_dev_rdy)
577 		return -EINVAL;
578 
579 	info = radeon_atcs_call(handle, ATCS_FUNCTION_PCIE_DEVICE_READY_NOTIFICATION, NULL);
580 	if (!info)
581 		return -EIO;
582 
583 	kfree(info);
584 
585 	return 0;
586 }
587 
588 /**
589  * radeon_acpi_pcie_performance_request
590  *
591  * @rdev: radeon_device pointer
592  * @perf_req: requested perf level (pcie gen speed)
593  * @advertise: set advertise caps flag if set
594  *
595  * Executes the PCIE_PERFORMANCE_REQUEST method to
596  * change the pcie gen speed (all asics).
597  * returns 0 on success, error on failure.
598  */
599 int radeon_acpi_pcie_performance_request(struct radeon_device *rdev,
600 					 u8 perf_req, bool advertise)
601 {
602 	acpi_handle handle;
603 	union acpi_object *info;
604 	struct radeon_atcs *atcs = &rdev->atcs;
605 	struct atcs_pref_req_input atcs_input;
606 	struct atcs_pref_req_output atcs_output;
607 	struct acpi_buffer params;
608 	size_t size;
609 	u32 retry = 3;
610 
611 	/* Get the device handle */
612 	handle = ACPI_HANDLE(&rdev->pdev->dev);
613 	if (!handle)
614 		return -EINVAL;
615 
616 	if (!atcs->functions.pcie_perf_req)
617 		return -EINVAL;
618 
619 	atcs_input.size = sizeof(struct atcs_pref_req_input);
620 	/* client id (bit 2-0: func num, 7-3: dev num, 15-8: bus num) */
621 	atcs_input.client_id = rdev->pdev->devfn | (rdev->pdev->bus->number << 8);
622 	atcs_input.valid_flags_mask = ATCS_VALID_FLAGS_MASK;
623 	atcs_input.flags = ATCS_WAIT_FOR_COMPLETION;
624 	if (advertise)
625 		atcs_input.flags |= ATCS_ADVERTISE_CAPS;
626 	atcs_input.req_type = ATCS_PCIE_LINK_SPEED;
627 	atcs_input.perf_req = perf_req;
628 
629 	params.length = sizeof(struct atcs_pref_req_input);
630 	params.pointer = &atcs_input;
631 
632 	while (retry--) {
633 		info = radeon_atcs_call(handle, ATCS_FUNCTION_PCIE_PERFORMANCE_REQUEST, &params);
634 		if (!info)
635 			return -EIO;
636 
637 		memset(&atcs_output, 0, sizeof(atcs_output));
638 
639 		size = *(u16 *) info->buffer.pointer;
640 		if (size < 3) {
641 			DRM_INFO("ATCS buffer is too small: %zu\n", size);
642 			kfree(info);
643 			return -EINVAL;
644 		}
645 		size = min(sizeof(atcs_output), size);
646 
647 		memcpy(&atcs_output, info->buffer.pointer, size);
648 
649 		kfree(info);
650 
651 		switch (atcs_output.ret_val) {
652 		case ATCS_REQUEST_REFUSED:
653 		default:
654 			return -EINVAL;
655 		case ATCS_REQUEST_COMPLETE:
656 			return 0;
657 		case ATCS_REQUEST_IN_PROGRESS:
658 			udelay(10);
659 			break;
660 		}
661 	}
662 
663 	return 0;
664 }
665 
666 /**
667  * radeon_acpi_event - handle notify events
668  *
669  * @nb: notifier block
670  * @val: val
671  * @data: acpi event
672  *
673  * Calls relevant radeon functions in response to various
674  * acpi events.
675  * Returns NOTIFY code
676  */
677 static int radeon_acpi_event(struct notifier_block *nb,
678 			     unsigned long val,
679 			     void *data)
680 {
681 	struct radeon_device *rdev = container_of(nb, struct radeon_device, acpi_nb);
682 	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
683 
684 	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
685 		if (power_supply_is_system_supplied() > 0)
686 			DRM_DEBUG_DRIVER("pm: AC\n");
687 		else
688 			DRM_DEBUG_DRIVER("pm: DC\n");
689 
690 		radeon_pm_acpi_event_handler(rdev);
691 	}
692 
693 	/* Check for pending SBIOS requests */
694 	return radeon_atif_handler(rdev, entry);
695 }
696 
697 /* Call all ACPI methods here */
698 /**
699  * radeon_acpi_init - init driver acpi support
700  *
701  * @rdev: radeon_device pointer
702  *
703  * Verifies the AMD ACPI interfaces and registers with the acpi
704  * notifier chain (all asics).
705  * Returns 0 on success, error on failure.
706  */
707 int radeon_acpi_init(struct radeon_device *rdev)
708 {
709 	acpi_handle handle;
710 	struct radeon_atif *atif = &rdev->atif;
711 	struct radeon_atcs *atcs = &rdev->atcs;
712 	int ret;
713 
714 	/* Get the device handle */
715 	handle = ACPI_HANDLE(&rdev->pdev->dev);
716 
717 	/* No need to proceed if we're sure that ATIF is not supported */
718 	if (!ASIC_IS_AVIVO(rdev) || !rdev->bios || !handle)
719 		return 0;
720 
721 	/* Call the ATCS method */
722 	ret = radeon_atcs_verify_interface(handle, atcs);
723 	if (ret) {
724 		DRM_DEBUG_DRIVER("Call to ATCS verify_interface failed: %d\n", ret);
725 	}
726 
727 	/* Call the ATIF method */
728 	ret = radeon_atif_verify_interface(handle, atif);
729 	if (ret) {
730 		DRM_DEBUG_DRIVER("Call to ATIF verify_interface failed: %d\n", ret);
731 		goto out;
732 	}
733 
734 	if (atif->notifications.brightness_change) {
735 		struct drm_encoder *tmp;
736 		struct radeon_encoder *target = NULL;
737 
738 		/* Find the encoder controlling the brightness */
739 		list_for_each_entry(tmp, &rdev->ddev->mode_config.encoder_list,
740 				head) {
741 			struct radeon_encoder *enc = to_radeon_encoder(tmp);
742 
743 			if ((enc->devices & (ATOM_DEVICE_LCD_SUPPORT)) &&
744 			    enc->enc_priv) {
745 				if (rdev->is_atom_bios) {
746 					struct radeon_encoder_atom_dig *dig = enc->enc_priv;
747 					if (dig->bl_dev) {
748 						target = enc;
749 						break;
750 					}
751 				} else {
752 					struct radeon_encoder_lvds *dig = enc->enc_priv;
753 					if (dig->bl_dev) {
754 						target = enc;
755 						break;
756 					}
757 				}
758 			}
759 		}
760 
761 		atif->encoder_for_bl = target;
762 	}
763 
764 	if (atif->functions.sbios_requests && !atif->functions.system_params) {
765 		/* XXX check this workraround, if sbios request function is
766 		 * present we have to see how it's configured in the system
767 		 * params
768 		 */
769 		atif->functions.system_params = true;
770 	}
771 
772 	if (atif->functions.system_params) {
773 		ret = radeon_atif_get_notification_params(handle,
774 				&atif->notification_cfg);
775 		if (ret) {
776 			DRM_DEBUG_DRIVER("Call to GET_SYSTEM_PARAMS failed: %d\n",
777 					ret);
778 			/* Disable notification */
779 			atif->notification_cfg.enabled = false;
780 		}
781 	}
782 
783 out:
784 	rdev->acpi_nb.notifier_call = radeon_acpi_event;
785 	register_acpi_notifier(&rdev->acpi_nb);
786 
787 	return ret;
788 }
789 
790 /**
791  * radeon_acpi_fini - tear down driver acpi support
792  *
793  * @rdev: radeon_device pointer
794  *
795  * Unregisters with the acpi notifier chain (all asics).
796  */
797 void radeon_acpi_fini(struct radeon_device *rdev)
798 {
799 	unregister_acpi_notifier(&rdev->acpi_nb);
800 }
801