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v6.9.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2010 Red Hat Inc.
  4 * Author : Dave Airlie <airlied@redhat.com>
  5 *
  6 * ATPX support for both Intel/ATI
  7 */
  8#include <linux/vga_switcheroo.h>
  9#include <linux/slab.h>
 10#include <linux/acpi.h>
 11#include <linux/pci.h>
 12#include <linux/delay.h>
 13
 14#include "amdgpu.h"
 15#include "amd_acpi.h"
 16
 17#define AMDGPU_PX_QUIRK_FORCE_ATPX  (1 << 0)
 18
 19struct amdgpu_px_quirk {
 20	u32 chip_vendor;
 21	u32 chip_device;
 22	u32 subsys_vendor;
 23	u32 subsys_device;
 24	u32 px_quirk_flags;
 25};
 26
 27struct amdgpu_atpx_functions {
 28	bool px_params;
 29	bool power_cntl;
 30	bool disp_mux_cntl;
 31	bool i2c_mux_cntl;
 32	bool switch_start;
 33	bool switch_end;
 34	bool disp_connectors_mapping;
 35	bool disp_detection_ports;
 36};
 37
 38struct amdgpu_atpx {
 39	acpi_handle handle;
 40	struct amdgpu_atpx_functions functions;
 41	bool is_hybrid;
 42	bool dgpu_req_power_for_displays;
 43};
 44
 45static struct amdgpu_atpx_priv {
 46	bool atpx_detected;
 47	bool bridge_pm_usable;
 48	unsigned int quirks;
 49	/* handle for device - and atpx */
 50	acpi_handle dhandle;
 51	acpi_handle other_handle;
 52	struct amdgpu_atpx atpx;
 53} amdgpu_atpx_priv;
 54
 55struct atpx_verify_interface {
 56	u16 size;		/* structure size in bytes (includes size field) */
 57	u16 version;		/* version */
 58	u32 function_bits;	/* supported functions bit vector */
 59} __packed;
 60
 61struct atpx_px_params {
 62	u16 size;		/* structure size in bytes (includes size field) */
 63	u32 valid_flags;	/* which flags are valid */
 64	u32 flags;		/* flags */
 65} __packed;
 66
 67struct atpx_power_control {
 68	u16 size;
 69	u8 dgpu_state;
 70} __packed;
 71
 72struct atpx_mux {
 73	u16 size;
 74	u16 mux;
 75} __packed;
 76
 77bool amdgpu_has_atpx(void)
 78{
 79	return amdgpu_atpx_priv.atpx_detected;
 80}
 81
 82bool amdgpu_has_atpx_dgpu_power_cntl(void)
 83{
 84	return amdgpu_atpx_priv.atpx.functions.power_cntl;
 85}
 86
 87bool amdgpu_is_atpx_hybrid(void)
 88{
 89	return amdgpu_atpx_priv.atpx.is_hybrid;
 90}
 91
 92bool amdgpu_atpx_dgpu_req_power_for_displays(void)
 93{
 94	return amdgpu_atpx_priv.atpx.dgpu_req_power_for_displays;
 95}
 96
 97#if defined(CONFIG_ACPI)
 98void *amdgpu_atpx_get_dhandle(void)
 99{
100	return amdgpu_atpx_priv.dhandle;
101}
102#endif
103
104/**
105 * amdgpu_atpx_call - call an ATPX method
106 *
107 * @handle: acpi handle
108 * @function: the ATPX function to execute
109 * @params: ATPX function params
110 *
111 * Executes the requested ATPX function (all asics).
112 * Returns a pointer to the acpi output buffer.
113 */
114static union acpi_object *amdgpu_atpx_call(acpi_handle handle, int function,
115					   struct acpi_buffer *params)
116{
117	acpi_status status;
118	union acpi_object atpx_arg_elements[2];
119	struct acpi_object_list atpx_arg;
120	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
121
122	atpx_arg.count = 2;
123	atpx_arg.pointer = &atpx_arg_elements[0];
124
125	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
126	atpx_arg_elements[0].integer.value = function;
127
128	if (params) {
129		atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
130		atpx_arg_elements[1].buffer.length = params->length;
131		atpx_arg_elements[1].buffer.pointer = params->pointer;
132	} else {
133		/* We need a second fake parameter */
134		atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
135		atpx_arg_elements[1].integer.value = 0;
136	}
137
138	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
139
140	/* Fail only if calling the method fails and ATPX is supported */
141	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
142		pr_err("failed to evaluate ATPX 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 * amdgpu_atpx_parse_functions - parse supported functions
153 *
154 * @f: supported functions struct
155 * @mask: supported functions mask from ATPX
156 *
157 * Use the supported functions mask from ATPX function
158 * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
159 * are supported (all asics).
160 */
161static void amdgpu_atpx_parse_functions(struct amdgpu_atpx_functions *f, u32 mask)
162{
163	f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
164	f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
165	f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
166	f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
167	f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
168	f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
169	f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
170	f->disp_detection_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
171}
172
173/**
174 * amdgpu_atpx_validate - validate ATPX functions
175 *
176 * @atpx: amdgpu atpx struct
177 *
178 * Validate that required functions are enabled (all asics).
179 * returns 0 on success, error on failure.
180 */
181static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx)
182{
183	u32 valid_bits = 0;
184
185	if (atpx->functions.px_params) {
186		union acpi_object *info;
187		struct atpx_px_params output;
188		size_t size;
189
190		info = amdgpu_atpx_call(atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
191		if (!info)
192			return -EIO;
193
194		memset(&output, 0, sizeof(output));
195
196		size = *(u16 *) info->buffer.pointer;
197		if (size < 10) {
198			pr_err("ATPX buffer is too small: %zu\n", size);
199			kfree(info);
200			return -EINVAL;
201		}
202		size = min(sizeof(output), size);
203
204		memcpy(&output, info->buffer.pointer, size);
205
206		valid_bits = output.flags & output.valid_flags;
207
208		kfree(info);
209	}
210
211	/* if separate mux flag is set, mux controls are required */
212	if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
213		atpx->functions.i2c_mux_cntl = true;
214		atpx->functions.disp_mux_cntl = true;
215	}
216	/* if any outputs are muxed, mux controls are required */
217	if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
218			  ATPX_TV_SIGNAL_MUXED |
219			  ATPX_DFP_SIGNAL_MUXED))
220		atpx->functions.disp_mux_cntl = true;
221
222
223	/* some bioses set these bits rather than flagging power_cntl as supported */
224	if (valid_bits & (ATPX_DYNAMIC_PX_SUPPORTED |
225			  ATPX_DYNAMIC_DGPU_POWER_OFF_SUPPORTED))
226		atpx->functions.power_cntl = true;
227
228	atpx->is_hybrid = false;
229	if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
230		if (amdgpu_atpx_priv.quirks & AMDGPU_PX_QUIRK_FORCE_ATPX) {
231			pr_warn("ATPX Hybrid Graphics, forcing to ATPX\n");
232			atpx->functions.power_cntl = true;
233			atpx->is_hybrid = false;
234		} else {
235			pr_notice("ATPX Hybrid Graphics\n");
236			/*
237			 * Disable legacy PM methods only when pcie port PM is usable,
238			 * otherwise the device might fail to power off or power on.
239			 */
240			atpx->functions.power_cntl = !amdgpu_atpx_priv.bridge_pm_usable;
241			atpx->is_hybrid = true;
242		}
243	}
244
245	atpx->dgpu_req_power_for_displays = false;
246	if (valid_bits & ATPX_DGPU_REQ_POWER_FOR_DISPLAYS)
247		atpx->dgpu_req_power_for_displays = true;
248
249	return 0;
250}
251
252/**
253 * amdgpu_atpx_verify_interface - verify ATPX
254 *
255 * @atpx: amdgpu atpx struct
256 *
257 * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
258 * to initialize ATPX and determine what features are supported
259 * (all asics).
260 * returns 0 on success, error on failure.
261 */
262static int amdgpu_atpx_verify_interface(struct amdgpu_atpx *atpx)
263{
264	union acpi_object *info;
265	struct atpx_verify_interface output;
266	size_t size;
267	int err = 0;
268
269	info = amdgpu_atpx_call(atpx->handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
270	if (!info)
271		return -EIO;
272
273	memset(&output, 0, sizeof(output));
274
275	size = *(u16 *) info->buffer.pointer;
276	if (size < 8) {
277		pr_err("ATPX buffer is too small: %zu\n", size);
278		err = -EINVAL;
279		goto out;
280	}
281	size = min(sizeof(output), size);
282
283	memcpy(&output, info->buffer.pointer, size);
284
285	/* TODO: check version? */
286	pr_notice("ATPX version %u, functions 0x%08x\n",
287		  output.version, output.function_bits);
288
289	amdgpu_atpx_parse_functions(&atpx->functions, output.function_bits);
290
291out:
292	kfree(info);
293	return err;
294}
295
296/**
297 * amdgpu_atpx_set_discrete_state - power up/down discrete GPU
298 *
299 * @atpx: atpx info struct
300 * @state: discrete GPU state (0 = power down, 1 = power up)
301 *
302 * Execute the ATPX_FUNCTION_POWER_CONTROL ATPX function to
303 * power down/up the discrete GPU (all asics).
304 * Returns 0 on success, error on failure.
305 */
306static int amdgpu_atpx_set_discrete_state(struct amdgpu_atpx *atpx, u8 state)
307{
308	struct acpi_buffer params;
309	union acpi_object *info;
310	struct atpx_power_control input;
311
312	if (atpx->functions.power_cntl) {
313		input.size = 3;
314		input.dgpu_state = state;
315		params.length = input.size;
316		params.pointer = &input;
317		info = amdgpu_atpx_call(atpx->handle,
318					ATPX_FUNCTION_POWER_CONTROL,
319					&params);
320		if (!info)
321			return -EIO;
322		kfree(info);
323
324		/* 200ms delay is required after off */
325		if (state == 0)
326			msleep(200);
327	}
328	return 0;
329}
330
331/**
332 * amdgpu_atpx_switch_disp_mux - switch display mux
333 *
334 * @atpx: atpx info struct
335 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
336 *
337 * Execute the ATPX_FUNCTION_DISPLAY_MUX_CONTROL ATPX function to
338 * switch the display mux between the discrete GPU and integrated GPU
339 * (all asics).
340 * Returns 0 on success, error on failure.
341 */
342static int amdgpu_atpx_switch_disp_mux(struct amdgpu_atpx *atpx, u16 mux_id)
343{
344	struct acpi_buffer params;
345	union acpi_object *info;
346	struct atpx_mux input;
347
348	if (atpx->functions.disp_mux_cntl) {
349		input.size = 4;
350		input.mux = mux_id;
351		params.length = input.size;
352		params.pointer = &input;
353		info = amdgpu_atpx_call(atpx->handle,
354					ATPX_FUNCTION_DISPLAY_MUX_CONTROL,
355					&params);
356		if (!info)
357			return -EIO;
358		kfree(info);
359	}
360	return 0;
361}
362
363/**
364 * amdgpu_atpx_switch_i2c_mux - switch i2c/hpd mux
365 *
366 * @atpx: atpx info struct
367 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
368 *
369 * Execute the ATPX_FUNCTION_I2C_MUX_CONTROL ATPX function to
370 * switch the i2c/hpd mux between the discrete GPU and integrated GPU
371 * (all asics).
372 * Returns 0 on success, error on failure.
373 */
374static int amdgpu_atpx_switch_i2c_mux(struct amdgpu_atpx *atpx, u16 mux_id)
375{
376	struct acpi_buffer params;
377	union acpi_object *info;
378	struct atpx_mux input;
379
380	if (atpx->functions.i2c_mux_cntl) {
381		input.size = 4;
382		input.mux = mux_id;
383		params.length = input.size;
384		params.pointer = &input;
385		info = amdgpu_atpx_call(atpx->handle,
386					ATPX_FUNCTION_I2C_MUX_CONTROL,
387					&params);
388		if (!info)
389			return -EIO;
390		kfree(info);
391	}
392	return 0;
393}
394
395/**
396 * amdgpu_atpx_switch_start - notify the sbios of a GPU switch
397 *
398 * @atpx: atpx info struct
399 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
400 *
401 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX
402 * function to notify the sbios that a switch between the discrete GPU and
403 * integrated GPU has begun (all asics).
404 * Returns 0 on success, error on failure.
405 */
406static int amdgpu_atpx_switch_start(struct amdgpu_atpx *atpx, u16 mux_id)
407{
408	struct acpi_buffer params;
409	union acpi_object *info;
410	struct atpx_mux input;
411
412	if (atpx->functions.switch_start) {
413		input.size = 4;
414		input.mux = mux_id;
415		params.length = input.size;
416		params.pointer = &input;
417		info = amdgpu_atpx_call(atpx->handle,
418					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION,
419					&params);
420		if (!info)
421			return -EIO;
422		kfree(info);
423	}
424	return 0;
425}
426
427/**
428 * amdgpu_atpx_switch_end - notify the sbios of a GPU switch
429 *
430 * @atpx: atpx info struct
431 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
432 *
433 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION ATPX
434 * function to notify the sbios that a switch between the discrete GPU and
435 * integrated GPU has ended (all asics).
436 * Returns 0 on success, error on failure.
437 */
438static int amdgpu_atpx_switch_end(struct amdgpu_atpx *atpx, u16 mux_id)
439{
440	struct acpi_buffer params;
441	union acpi_object *info;
442	struct atpx_mux input;
443
444	if (atpx->functions.switch_end) {
445		input.size = 4;
446		input.mux = mux_id;
447		params.length = input.size;
448		params.pointer = &input;
449		info = amdgpu_atpx_call(atpx->handle,
450					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION,
451					&params);
452		if (!info)
453			return -EIO;
454		kfree(info);
455	}
456	return 0;
457}
458
459/**
460 * amdgpu_atpx_switchto - switch to the requested GPU
461 *
462 * @id: GPU to switch to
463 *
464 * Execute the necessary ATPX functions to switch between the discrete GPU and
465 * integrated GPU (all asics).
466 * Returns 0 on success, error on failure.
467 */
468static int amdgpu_atpx_switchto(enum vga_switcheroo_client_id id)
469{
470	u16 gpu_id;
471
472	if (id == VGA_SWITCHEROO_IGD)
473		gpu_id = ATPX_INTEGRATED_GPU;
474	else
475		gpu_id = ATPX_DISCRETE_GPU;
476
477	amdgpu_atpx_switch_start(&amdgpu_atpx_priv.atpx, gpu_id);
478	amdgpu_atpx_switch_disp_mux(&amdgpu_atpx_priv.atpx, gpu_id);
479	amdgpu_atpx_switch_i2c_mux(&amdgpu_atpx_priv.atpx, gpu_id);
480	amdgpu_atpx_switch_end(&amdgpu_atpx_priv.atpx, gpu_id);
481
482	return 0;
483}
484
485/**
486 * amdgpu_atpx_power_state - power down/up the requested GPU
487 *
488 * @id: GPU to power down/up
489 * @state: requested power state (0 = off, 1 = on)
490 *
491 * Execute the necessary ATPX function to power down/up the discrete GPU
492 * (all asics).
493 * Returns 0 on success, error on failure.
494 */
495static int amdgpu_atpx_power_state(enum vga_switcheroo_client_id id,
496				   enum vga_switcheroo_state state)
497{
498	/* on w500 ACPI can't change intel gpu state */
499	if (id == VGA_SWITCHEROO_IGD)
500		return 0;
501
502	amdgpu_atpx_set_discrete_state(&amdgpu_atpx_priv.atpx, state);
503	return 0;
504}
505
506/**
507 * amdgpu_atpx_pci_probe_handle - look up the ATPX handle
508 *
509 * @pdev: pci device
510 *
511 * Look up the ATPX handles (all asics).
512 * Returns true if the handles are found, false if not.
513 */
514static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
515{
516	acpi_handle dhandle, atpx_handle;
517	acpi_status status;
518
519	dhandle = ACPI_HANDLE(&pdev->dev);
520	if (!dhandle)
521		return false;
522
523	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
524	if (ACPI_FAILURE(status)) {
525		amdgpu_atpx_priv.other_handle = dhandle;
526		return false;
527	}
528	amdgpu_atpx_priv.dhandle = dhandle;
529	amdgpu_atpx_priv.atpx.handle = atpx_handle;
530	return true;
531}
532
533/**
534 * amdgpu_atpx_init - verify the ATPX interface
535 *
536 * Verify the ATPX interface (all asics).
537 * Returns 0 on success, error on failure.
538 */
539static int amdgpu_atpx_init(void)
540{
541	int r;
542
543	/* set up the ATPX handle */
544	r = amdgpu_atpx_verify_interface(&amdgpu_atpx_priv.atpx);
545	if (r)
546		return r;
547
548	/* validate the atpx setup */
549	r = amdgpu_atpx_validate(&amdgpu_atpx_priv.atpx);
550	if (r)
551		return r;
552
553	return 0;
554}
555
556/**
557 * amdgpu_atpx_get_client_id - get the client id
558 *
559 * @pdev: pci device
560 *
561 * look up whether we are the integrated or discrete GPU (all asics).
562 * Returns the client id.
563 */
564static enum vga_switcheroo_client_id amdgpu_atpx_get_client_id(struct pci_dev *pdev)
565{
566	if (amdgpu_atpx_priv.dhandle == ACPI_HANDLE(&pdev->dev))
567		return VGA_SWITCHEROO_IGD;
568	else
569		return VGA_SWITCHEROO_DIS;
570}
571
572static const struct vga_switcheroo_handler amdgpu_atpx_handler = {
573	.switchto = amdgpu_atpx_switchto,
574	.power_state = amdgpu_atpx_power_state,
575	.get_client_id = amdgpu_atpx_get_client_id,
576};
577
578static const struct amdgpu_px_quirk amdgpu_px_quirk_list[] = {
579	/* HG _PR3 doesn't seem to work on this A+A weston board */
580	{ 0x1002, 0x6900, 0x1002, 0x0124, AMDGPU_PX_QUIRK_FORCE_ATPX },
581	{ 0x1002, 0x6900, 0x1028, 0x0812, AMDGPU_PX_QUIRK_FORCE_ATPX },
582	{ 0x1002, 0x6900, 0x1028, 0x0813, AMDGPU_PX_QUIRK_FORCE_ATPX },
583	{ 0x1002, 0x699f, 0x1028, 0x0814, AMDGPU_PX_QUIRK_FORCE_ATPX },
584	{ 0x1002, 0x6900, 0x1025, 0x125A, AMDGPU_PX_QUIRK_FORCE_ATPX },
585	{ 0x1002, 0x6900, 0x17AA, 0x3806, AMDGPU_PX_QUIRK_FORCE_ATPX },
586	{ 0, 0, 0, 0, 0 },
587};
588
589static void amdgpu_atpx_get_quirks(struct pci_dev *pdev)
590{
591	const struct amdgpu_px_quirk *p = amdgpu_px_quirk_list;
592
593	/* Apply PX quirks */
594	while (p && p->chip_device != 0) {
595		if (pdev->vendor == p->chip_vendor &&
596		    pdev->device == p->chip_device &&
597		    pdev->subsystem_vendor == p->subsys_vendor &&
598		    pdev->subsystem_device == p->subsys_device) {
599			amdgpu_atpx_priv.quirks |= p->px_quirk_flags;
600			break;
601		}
602		++p;
603	}
604}
605
606/**
607 * amdgpu_atpx_detect - detect whether we have PX
608 *
609 * Check if we have a PX system (all asics).
610 * Returns true if we have a PX system, false if not.
611 */
612static bool amdgpu_atpx_detect(void)
613{
614	char acpi_method_name[255] = { 0 };
615	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
616	struct pci_dev *pdev = NULL;
617	bool has_atpx = false;
618	int vga_count = 0;
619	bool d3_supported = false;
620	struct pci_dev *parent_pdev;
621
622	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
623		vga_count++;
624
625		has_atpx |= amdgpu_atpx_pci_probe_handle(pdev);
626
627		parent_pdev = pci_upstream_bridge(pdev);
628		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
629		amdgpu_atpx_get_quirks(pdev);
630	}
631
632	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
633		vga_count++;
634
635		has_atpx |= amdgpu_atpx_pci_probe_handle(pdev);
636
637		parent_pdev = pci_upstream_bridge(pdev);
638		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
639		amdgpu_atpx_get_quirks(pdev);
640	}
641
642	if (has_atpx && vga_count == 2) {
643		acpi_get_name(amdgpu_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
644		pr_info("vga_switcheroo: detected switching method %s handle\n",
645			acpi_method_name);
646		amdgpu_atpx_priv.atpx_detected = true;
647		amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
648		amdgpu_atpx_init();
649		return true;
650	}
651	return false;
652}
653
654/**
655 * amdgpu_register_atpx_handler - register with vga_switcheroo
656 *
657 * Register the PX callbacks with vga_switcheroo (all asics).
658 */
659void amdgpu_register_atpx_handler(void)
660{
661	bool r;
662	enum vga_switcheroo_handler_flags_t handler_flags = 0;
663
664	/* detect if we have any ATPX + 2 VGA in the system */
665	r = amdgpu_atpx_detect();
666	if (!r)
667		return;
668
669	vga_switcheroo_register_handler(&amdgpu_atpx_handler, handler_flags);
670}
671
672/**
673 * amdgpu_unregister_atpx_handler - unregister with vga_switcheroo
674 *
675 * Unregister the PX callbacks with vga_switcheroo (all asics).
676 */
677void amdgpu_unregister_atpx_handler(void)
678{
679	vga_switcheroo_unregister_handler();
680}
v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2010 Red Hat Inc.
  4 * Author : Dave Airlie <airlied@redhat.com>
  5 *
  6 * ATPX support for both Intel/ATI
  7 */
  8#include <linux/vga_switcheroo.h>
  9#include <linux/slab.h>
 10#include <linux/acpi.h>
 11#include <linux/pci.h>
 12#include <linux/delay.h>
 13
 
 14#include "amd_acpi.h"
 15
 16#define AMDGPU_PX_QUIRK_FORCE_ATPX  (1 << 0)
 17
 18struct amdgpu_px_quirk {
 19	u32 chip_vendor;
 20	u32 chip_device;
 21	u32 subsys_vendor;
 22	u32 subsys_device;
 23	u32 px_quirk_flags;
 24};
 25
 26struct amdgpu_atpx_functions {
 27	bool px_params;
 28	bool power_cntl;
 29	bool disp_mux_cntl;
 30	bool i2c_mux_cntl;
 31	bool switch_start;
 32	bool switch_end;
 33	bool disp_connectors_mapping;
 34	bool disp_detection_ports;
 35};
 36
 37struct amdgpu_atpx {
 38	acpi_handle handle;
 39	struct amdgpu_atpx_functions functions;
 40	bool is_hybrid;
 41	bool dgpu_req_power_for_displays;
 42};
 43
 44static struct amdgpu_atpx_priv {
 45	bool atpx_detected;
 46	bool bridge_pm_usable;
 47	unsigned int quirks;
 48	/* handle for device - and atpx */
 49	acpi_handle dhandle;
 50	acpi_handle other_handle;
 51	struct amdgpu_atpx atpx;
 52} amdgpu_atpx_priv;
 53
 54struct atpx_verify_interface {
 55	u16 size;		/* structure size in bytes (includes size field) */
 56	u16 version;		/* version */
 57	u32 function_bits;	/* supported functions bit vector */
 58} __packed;
 59
 60struct atpx_px_params {
 61	u16 size;		/* structure size in bytes (includes size field) */
 62	u32 valid_flags;	/* which flags are valid */
 63	u32 flags;		/* flags */
 64} __packed;
 65
 66struct atpx_power_control {
 67	u16 size;
 68	u8 dgpu_state;
 69} __packed;
 70
 71struct atpx_mux {
 72	u16 size;
 73	u16 mux;
 74} __packed;
 75
 76bool amdgpu_has_atpx(void) {
 
 77	return amdgpu_atpx_priv.atpx_detected;
 78}
 79
 80bool amdgpu_has_atpx_dgpu_power_cntl(void) {
 
 81	return amdgpu_atpx_priv.atpx.functions.power_cntl;
 82}
 83
 84bool amdgpu_is_atpx_hybrid(void) {
 
 85	return amdgpu_atpx_priv.atpx.is_hybrid;
 86}
 87
 88bool amdgpu_atpx_dgpu_req_power_for_displays(void) {
 
 89	return amdgpu_atpx_priv.atpx.dgpu_req_power_for_displays;
 90}
 91
 92#if defined(CONFIG_ACPI)
 93void *amdgpu_atpx_get_dhandle(void) {
 
 94	return amdgpu_atpx_priv.dhandle;
 95}
 96#endif
 97
 98/**
 99 * amdgpu_atpx_call - call an ATPX method
100 *
101 * @handle: acpi handle
102 * @function: the ATPX function to execute
103 * @params: ATPX function params
104 *
105 * Executes the requested ATPX function (all asics).
106 * Returns a pointer to the acpi output buffer.
107 */
108static union acpi_object *amdgpu_atpx_call(acpi_handle handle, int function,
109					   struct acpi_buffer *params)
110{
111	acpi_status status;
112	union acpi_object atpx_arg_elements[2];
113	struct acpi_object_list atpx_arg;
114	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
115
116	atpx_arg.count = 2;
117	atpx_arg.pointer = &atpx_arg_elements[0];
118
119	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
120	atpx_arg_elements[0].integer.value = function;
121
122	if (params) {
123		atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
124		atpx_arg_elements[1].buffer.length = params->length;
125		atpx_arg_elements[1].buffer.pointer = params->pointer;
126	} else {
127		/* We need a second fake parameter */
128		atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
129		atpx_arg_elements[1].integer.value = 0;
130	}
131
132	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
133
134	/* Fail only if calling the method fails and ATPX is supported */
135	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
136		printk("failed to evaluate ATPX got %s\n",
137		       acpi_format_exception(status));
138		kfree(buffer.pointer);
139		return NULL;
140	}
141
142	return buffer.pointer;
143}
144
145/**
146 * amdgpu_atpx_parse_functions - parse supported functions
147 *
148 * @f: supported functions struct
149 * @mask: supported functions mask from ATPX
150 *
151 * Use the supported functions mask from ATPX function
152 * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
153 * are supported (all asics).
154 */
155static void amdgpu_atpx_parse_functions(struct amdgpu_atpx_functions *f, u32 mask)
156{
157	f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
158	f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
159	f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
160	f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
161	f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
162	f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
163	f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
164	f->disp_detection_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
165}
166
167/**
168 * amdgpu_atpx_validate_functions - validate ATPX functions
169 *
170 * @atpx: amdgpu atpx struct
171 *
172 * Validate that required functions are enabled (all asics).
173 * returns 0 on success, error on failure.
174 */
175static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx)
176{
177	u32 valid_bits = 0;
178
179	if (atpx->functions.px_params) {
180		union acpi_object *info;
181		struct atpx_px_params output;
182		size_t size;
183
184		info = amdgpu_atpx_call(atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
185		if (!info)
186			return -EIO;
187
188		memset(&output, 0, sizeof(output));
189
190		size = *(u16 *) info->buffer.pointer;
191		if (size < 10) {
192			printk("ATPX buffer is too small: %zu\n", size);
193			kfree(info);
194			return -EINVAL;
195		}
196		size = min(sizeof(output), size);
197
198		memcpy(&output, info->buffer.pointer, size);
199
200		valid_bits = output.flags & output.valid_flags;
201
202		kfree(info);
203	}
204
205	/* if separate mux flag is set, mux controls are required */
206	if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
207		atpx->functions.i2c_mux_cntl = true;
208		atpx->functions.disp_mux_cntl = true;
209	}
210	/* if any outputs are muxed, mux controls are required */
211	if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
212			  ATPX_TV_SIGNAL_MUXED |
213			  ATPX_DFP_SIGNAL_MUXED))
214		atpx->functions.disp_mux_cntl = true;
215
216
217	/* some bioses set these bits rather than flagging power_cntl as supported */
218	if (valid_bits & (ATPX_DYNAMIC_PX_SUPPORTED |
219			  ATPX_DYNAMIC_DGPU_POWER_OFF_SUPPORTED))
220		atpx->functions.power_cntl = true;
221
222	atpx->is_hybrid = false;
223	if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
224		if (amdgpu_atpx_priv.quirks & AMDGPU_PX_QUIRK_FORCE_ATPX) {
225			printk("ATPX Hybrid Graphics, forcing to ATPX\n");
226			atpx->functions.power_cntl = true;
227			atpx->is_hybrid = false;
228		} else {
229			printk("ATPX Hybrid Graphics\n");
230			/*
231			 * Disable legacy PM methods only when pcie port PM is usable,
232			 * otherwise the device might fail to power off or power on.
233			 */
234			atpx->functions.power_cntl = !amdgpu_atpx_priv.bridge_pm_usable;
235			atpx->is_hybrid = true;
236		}
237	}
238
239	atpx->dgpu_req_power_for_displays = false;
240	if (valid_bits & ATPX_DGPU_REQ_POWER_FOR_DISPLAYS)
241		atpx->dgpu_req_power_for_displays = true;
242
243	return 0;
244}
245
246/**
247 * amdgpu_atpx_verify_interface - verify ATPX
248 *
249 * @atpx: amdgpu atpx struct
250 *
251 * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
252 * to initialize ATPX and determine what features are supported
253 * (all asics).
254 * returns 0 on success, error on failure.
255 */
256static int amdgpu_atpx_verify_interface(struct amdgpu_atpx *atpx)
257{
258	union acpi_object *info;
259	struct atpx_verify_interface output;
260	size_t size;
261	int err = 0;
262
263	info = amdgpu_atpx_call(atpx->handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
264	if (!info)
265		return -EIO;
266
267	memset(&output, 0, sizeof(output));
268
269	size = *(u16 *) info->buffer.pointer;
270	if (size < 8) {
271		printk("ATPX buffer is too small: %zu\n", size);
272		err = -EINVAL;
273		goto out;
274	}
275	size = min(sizeof(output), size);
276
277	memcpy(&output, info->buffer.pointer, size);
278
279	/* TODO: check version? */
280	printk("ATPX version %u, functions 0x%08x\n",
281	       output.version, output.function_bits);
282
283	amdgpu_atpx_parse_functions(&atpx->functions, output.function_bits);
284
285out:
286	kfree(info);
287	return err;
288}
289
290/**
291 * amdgpu_atpx_set_discrete_state - power up/down discrete GPU
292 *
293 * @atpx: atpx info struct
294 * @state: discrete GPU state (0 = power down, 1 = power up)
295 *
296 * Execute the ATPX_FUNCTION_POWER_CONTROL ATPX function to
297 * power down/up the discrete GPU (all asics).
298 * Returns 0 on success, error on failure.
299 */
300static int amdgpu_atpx_set_discrete_state(struct amdgpu_atpx *atpx, u8 state)
301{
302	struct acpi_buffer params;
303	union acpi_object *info;
304	struct atpx_power_control input;
305
306	if (atpx->functions.power_cntl) {
307		input.size = 3;
308		input.dgpu_state = state;
309		params.length = input.size;
310		params.pointer = &input;
311		info = amdgpu_atpx_call(atpx->handle,
312					ATPX_FUNCTION_POWER_CONTROL,
313					&params);
314		if (!info)
315			return -EIO;
316		kfree(info);
317
318		/* 200ms delay is required after off */
319		if (state == 0)
320			msleep(200);
321	}
322	return 0;
323}
324
325/**
326 * amdgpu_atpx_switch_disp_mux - switch display mux
327 *
328 * @atpx: atpx info struct
329 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
330 *
331 * Execute the ATPX_FUNCTION_DISPLAY_MUX_CONTROL ATPX function to
332 * switch the display mux between the discrete GPU and integrated GPU
333 * (all asics).
334 * Returns 0 on success, error on failure.
335 */
336static int amdgpu_atpx_switch_disp_mux(struct amdgpu_atpx *atpx, u16 mux_id)
337{
338	struct acpi_buffer params;
339	union acpi_object *info;
340	struct atpx_mux input;
341
342	if (atpx->functions.disp_mux_cntl) {
343		input.size = 4;
344		input.mux = mux_id;
345		params.length = input.size;
346		params.pointer = &input;
347		info = amdgpu_atpx_call(atpx->handle,
348					ATPX_FUNCTION_DISPLAY_MUX_CONTROL,
349					&params);
350		if (!info)
351			return -EIO;
352		kfree(info);
353	}
354	return 0;
355}
356
357/**
358 * amdgpu_atpx_switch_i2c_mux - switch i2c/hpd mux
359 *
360 * @atpx: atpx info struct
361 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
362 *
363 * Execute the ATPX_FUNCTION_I2C_MUX_CONTROL ATPX function to
364 * switch the i2c/hpd mux between the discrete GPU and integrated GPU
365 * (all asics).
366 * Returns 0 on success, error on failure.
367 */
368static int amdgpu_atpx_switch_i2c_mux(struct amdgpu_atpx *atpx, u16 mux_id)
369{
370	struct acpi_buffer params;
371	union acpi_object *info;
372	struct atpx_mux input;
373
374	if (atpx->functions.i2c_mux_cntl) {
375		input.size = 4;
376		input.mux = mux_id;
377		params.length = input.size;
378		params.pointer = &input;
379		info = amdgpu_atpx_call(atpx->handle,
380					ATPX_FUNCTION_I2C_MUX_CONTROL,
381					&params);
382		if (!info)
383			return -EIO;
384		kfree(info);
385	}
386	return 0;
387}
388
389/**
390 * amdgpu_atpx_switch_start - notify the sbios of a GPU switch
391 *
392 * @atpx: atpx info struct
393 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
394 *
395 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX
396 * function to notify the sbios that a switch between the discrete GPU and
397 * integrated GPU has begun (all asics).
398 * Returns 0 on success, error on failure.
399 */
400static int amdgpu_atpx_switch_start(struct amdgpu_atpx *atpx, u16 mux_id)
401{
402	struct acpi_buffer params;
403	union acpi_object *info;
404	struct atpx_mux input;
405
406	if (atpx->functions.switch_start) {
407		input.size = 4;
408		input.mux = mux_id;
409		params.length = input.size;
410		params.pointer = &input;
411		info = amdgpu_atpx_call(atpx->handle,
412					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION,
413					&params);
414		if (!info)
415			return -EIO;
416		kfree(info);
417	}
418	return 0;
419}
420
421/**
422 * amdgpu_atpx_switch_end - notify the sbios of a GPU switch
423 *
424 * @atpx: atpx info struct
425 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
426 *
427 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION ATPX
428 * function to notify the sbios that a switch between the discrete GPU and
429 * integrated GPU has ended (all asics).
430 * Returns 0 on success, error on failure.
431 */
432static int amdgpu_atpx_switch_end(struct amdgpu_atpx *atpx, u16 mux_id)
433{
434	struct acpi_buffer params;
435	union acpi_object *info;
436	struct atpx_mux input;
437
438	if (atpx->functions.switch_end) {
439		input.size = 4;
440		input.mux = mux_id;
441		params.length = input.size;
442		params.pointer = &input;
443		info = amdgpu_atpx_call(atpx->handle,
444					ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION,
445					&params);
446		if (!info)
447			return -EIO;
448		kfree(info);
449	}
450	return 0;
451}
452
453/**
454 * amdgpu_atpx_switchto - switch to the requested GPU
455 *
456 * @id: GPU to switch to
457 *
458 * Execute the necessary ATPX functions to switch between the discrete GPU and
459 * integrated GPU (all asics).
460 * Returns 0 on success, error on failure.
461 */
462static int amdgpu_atpx_switchto(enum vga_switcheroo_client_id id)
463{
464	u16 gpu_id;
465
466	if (id == VGA_SWITCHEROO_IGD)
467		gpu_id = ATPX_INTEGRATED_GPU;
468	else
469		gpu_id = ATPX_DISCRETE_GPU;
470
471	amdgpu_atpx_switch_start(&amdgpu_atpx_priv.atpx, gpu_id);
472	amdgpu_atpx_switch_disp_mux(&amdgpu_atpx_priv.atpx, gpu_id);
473	amdgpu_atpx_switch_i2c_mux(&amdgpu_atpx_priv.atpx, gpu_id);
474	amdgpu_atpx_switch_end(&amdgpu_atpx_priv.atpx, gpu_id);
475
476	return 0;
477}
478
479/**
480 * amdgpu_atpx_power_state - power down/up the requested GPU
481 *
482 * @id: GPU to power down/up
483 * @state: requested power state (0 = off, 1 = on)
484 *
485 * Execute the necessary ATPX function to power down/up the discrete GPU
486 * (all asics).
487 * Returns 0 on success, error on failure.
488 */
489static int amdgpu_atpx_power_state(enum vga_switcheroo_client_id id,
490				   enum vga_switcheroo_state state)
491{
492	/* on w500 ACPI can't change intel gpu state */
493	if (id == VGA_SWITCHEROO_IGD)
494		return 0;
495
496	amdgpu_atpx_set_discrete_state(&amdgpu_atpx_priv.atpx, state);
497	return 0;
498}
499
500/**
501 * amdgpu_atpx_pci_probe_handle - look up the ATPX handle
502 *
503 * @pdev: pci device
504 *
505 * Look up the ATPX handles (all asics).
506 * Returns true if the handles are found, false if not.
507 */
508static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
509{
510	acpi_handle dhandle, atpx_handle;
511	acpi_status status;
512
513	dhandle = ACPI_HANDLE(&pdev->dev);
514	if (!dhandle)
515		return false;
516
517	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
518	if (ACPI_FAILURE(status)) {
519		amdgpu_atpx_priv.other_handle = dhandle;
520		return false;
521	}
522	amdgpu_atpx_priv.dhandle = dhandle;
523	amdgpu_atpx_priv.atpx.handle = atpx_handle;
524	return true;
525}
526
527/**
528 * amdgpu_atpx_init - verify the ATPX interface
529 *
530 * Verify the ATPX interface (all asics).
531 * Returns 0 on success, error on failure.
532 */
533static int amdgpu_atpx_init(void)
534{
535	int r;
536
537	/* set up the ATPX handle */
538	r = amdgpu_atpx_verify_interface(&amdgpu_atpx_priv.atpx);
539	if (r)
540		return r;
541
542	/* validate the atpx setup */
543	r = amdgpu_atpx_validate(&amdgpu_atpx_priv.atpx);
544	if (r)
545		return r;
546
547	return 0;
548}
549
550/**
551 * amdgpu_atpx_get_client_id - get the client id
552 *
553 * @pdev: pci device
554 *
555 * look up whether we are the integrated or discrete GPU (all asics).
556 * Returns the client id.
557 */
558static enum vga_switcheroo_client_id amdgpu_atpx_get_client_id(struct pci_dev *pdev)
559{
560	if (amdgpu_atpx_priv.dhandle == ACPI_HANDLE(&pdev->dev))
561		return VGA_SWITCHEROO_IGD;
562	else
563		return VGA_SWITCHEROO_DIS;
564}
565
566static const struct vga_switcheroo_handler amdgpu_atpx_handler = {
567	.switchto = amdgpu_atpx_switchto,
568	.power_state = amdgpu_atpx_power_state,
569	.get_client_id = amdgpu_atpx_get_client_id,
570};
571
572static const struct amdgpu_px_quirk amdgpu_px_quirk_list[] = {
573	/* HG _PR3 doesn't seem to work on this A+A weston board */
574	{ 0x1002, 0x6900, 0x1002, 0x0124, AMDGPU_PX_QUIRK_FORCE_ATPX },
575	{ 0x1002, 0x6900, 0x1028, 0x0812, AMDGPU_PX_QUIRK_FORCE_ATPX },
576	{ 0x1002, 0x6900, 0x1028, 0x0813, AMDGPU_PX_QUIRK_FORCE_ATPX },
577	{ 0x1002, 0x699f, 0x1028, 0x0814, AMDGPU_PX_QUIRK_FORCE_ATPX },
578	{ 0x1002, 0x6900, 0x1025, 0x125A, AMDGPU_PX_QUIRK_FORCE_ATPX },
579	{ 0x1002, 0x6900, 0x17AA, 0x3806, AMDGPU_PX_QUIRK_FORCE_ATPX },
580	{ 0, 0, 0, 0, 0 },
581};
582
583static void amdgpu_atpx_get_quirks(struct pci_dev *pdev)
584{
585	const struct amdgpu_px_quirk *p = amdgpu_px_quirk_list;
586
587	/* Apply PX quirks */
588	while (p && p->chip_device != 0) {
589		if (pdev->vendor == p->chip_vendor &&
590		    pdev->device == p->chip_device &&
591		    pdev->subsystem_vendor == p->subsys_vendor &&
592		    pdev->subsystem_device == p->subsys_device) {
593			amdgpu_atpx_priv.quirks |= p->px_quirk_flags;
594			break;
595		}
596		++p;
597	}
598}
599
600/**
601 * amdgpu_atpx_detect - detect whether we have PX
602 *
603 * Check if we have a PX system (all asics).
604 * Returns true if we have a PX system, false if not.
605 */
606static bool amdgpu_atpx_detect(void)
607{
608	char acpi_method_name[255] = { 0 };
609	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
610	struct pci_dev *pdev = NULL;
611	bool has_atpx = false;
612	int vga_count = 0;
613	bool d3_supported = false;
614	struct pci_dev *parent_pdev;
615
616	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
617		vga_count++;
618
619		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
620
621		parent_pdev = pci_upstream_bridge(pdev);
622		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
623		amdgpu_atpx_get_quirks(pdev);
624	}
625
626	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
627		vga_count++;
628
629		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
630
631		parent_pdev = pci_upstream_bridge(pdev);
632		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
633		amdgpu_atpx_get_quirks(pdev);
634	}
635
636	if (has_atpx && vga_count == 2) {
637		acpi_get_name(amdgpu_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
638		pr_info("vga_switcheroo: detected switching method %s handle\n",
639			acpi_method_name);
640		amdgpu_atpx_priv.atpx_detected = true;
641		amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
642		amdgpu_atpx_init();
643		return true;
644	}
645	return false;
646}
647
648/**
649 * amdgpu_register_atpx_handler - register with vga_switcheroo
650 *
651 * Register the PX callbacks with vga_switcheroo (all asics).
652 */
653void amdgpu_register_atpx_handler(void)
654{
655	bool r;
656	enum vga_switcheroo_handler_flags_t handler_flags = 0;
657
658	/* detect if we have any ATPX + 2 VGA in the system */
659	r = amdgpu_atpx_detect();
660	if (!r)
661		return;
662
663	vga_switcheroo_register_handler(&amdgpu_atpx_handler, handler_flags);
664}
665
666/**
667 * amdgpu_unregister_atpx_handler - unregister with vga_switcheroo
668 *
669 * Unregister the PX callbacks with vga_switcheroo (all asics).
670 */
671void amdgpu_unregister_atpx_handler(void)
672{
673	vga_switcheroo_unregister_handler();
674}