1 /*
2  * Copyright (c) 2006-2008 Intel Corporation
3  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4  *
5  * DRM core CRTC related functions
6  *
7  * Permission to use, copy, modify, distribute, and sell this software and its
8  * documentation for any purpose is hereby granted without fee, provided that
9  * the above copyright notice appear in all copies and that both that copyright
10  * notice and this permission notice appear in supporting documentation, and
11  * that the name of the copyright holders not be used in advertising or
12  * publicity pertaining to distribution of the software without specific,
13  * written prior permission.  The copyright holders make no representations
14  * about the suitability of this software for any purpose.  It is provided "as
15  * is" without express or implied warranty.
16  *
17  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
19  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
20  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
22  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23  * OF THIS SOFTWARE.
24  *
25  * Authors:
26  *      Keith Packard
27  *	Eric Anholt <eric@anholt.net>
28  *      Dave Airlie <airlied@linux.ie>
29  *      Jesse Barnes <jesse.barnes@intel.com>
30  */
31 
32 #include <linux/kernel.h>
33 #include <linux/export.h>
34 #include <linux/moduleparam.h>
35 
36 #include <drm/drmP.h>
37 #include <drm/drm_atomic.h>
38 #include <drm/drm_crtc.h>
39 #include <drm/drm_fourcc.h>
40 #include <drm/drm_crtc_helper.h>
41 #include <drm/drm_fb_helper.h>
42 #include <drm/drm_plane_helper.h>
43 #include <drm/drm_atomic_helper.h>
44 #include <drm/drm_edid.h>
45 
46 /**
47  * DOC: overview
48  *
49  * The CRTC modeset helper library provides a default set_config implementation
50  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
51  * the same callbacks which drivers can use to e.g. restore the modeset
52  * configuration on resume with drm_helper_resume_force_mode().
53  *
54  * Note that this helper library doesn't track the current power state of CRTCs
55  * and encoders. It can call callbacks like ->dpms() even though the hardware is
56  * already in the desired state. This deficiency has been fixed in the atomic
57  * helpers.
58  *
59  * The driver callbacks are mostly compatible with the atomic modeset helpers,
60  * except for the handling of the primary plane: Atomic helpers require that the
61  * primary plane is implemented as a real standalone plane and not directly tied
62  * to the CRTC state. For easier transition this library provides functions to
63  * implement the old semantics required by the CRTC helpers using the new plane
64  * and atomic helper callbacks.
65  *
66  * Drivers are strongly urged to convert to the atomic helpers (by way of first
67  * converting to the plane helpers). New drivers must not use these functions
68  * but need to implement the atomic interface instead, potentially using the
69  * atomic helpers for that.
70  *
71  * These legacy modeset helpers use the same function table structures as
72  * all other modesetting helpers. See the documentation for struct
73  * &drm_crtc_helper_funcs, struct &drm_encoder_helper_funcs and struct
74  * &drm_connector_helper_funcs.
75  */
76 
77 /**
78  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
79  * 						connector list
80  * @dev: drm device to operate on
81  *
82  * Some userspace presumes that the first connected connector is the main
83  * display, where it's supposed to display e.g. the login screen. For
84  * laptops, this should be the main panel. Use this function to sort all
85  * (eDP/LVDS) panels to the front of the connector list, instead of
86  * painstakingly trying to initialize them in the right order.
87  */
88 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
89 {
90 	struct drm_connector *connector, *tmp;
91 	struct list_head panel_list;
92 
93 	INIT_LIST_HEAD(&panel_list);
94 
95 	list_for_each_entry_safe(connector, tmp,
96 				 &dev->mode_config.connector_list, head) {
97 		if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
98 		    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
99 			list_move_tail(&connector->head, &panel_list);
100 	}
101 
102 	list_splice(&panel_list, &dev->mode_config.connector_list);
103 }
104 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
105 
106 /**
107  * drm_helper_encoder_in_use - check if a given encoder is in use
108  * @encoder: encoder to check
109  *
110  * Checks whether @encoder is with the current mode setting output configuration
111  * in use by any connector. This doesn't mean that it is actually enabled since
112  * the DPMS state is tracked separately.
113  *
114  * Returns:
115  * True if @encoder is used, false otherwise.
116  */
117 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
118 {
119 	struct drm_connector *connector;
120 	struct drm_device *dev = encoder->dev;
121 
122 	/*
123 	 * We can expect this mutex to be locked if we are not panicking.
124 	 * Locking is currently fubar in the panic handler.
125 	 */
126 	if (!oops_in_progress) {
127 		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
128 		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
129 	}
130 
131 	drm_for_each_connector(connector, dev)
132 		if (connector->encoder == encoder)
133 			return true;
134 	return false;
135 }
136 EXPORT_SYMBOL(drm_helper_encoder_in_use);
137 
138 /**
139  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
140  * @crtc: CRTC to check
141  *
142  * Checks whether @crtc is with the current mode setting output configuration
143  * in use by any connector. This doesn't mean that it is actually enabled since
144  * the DPMS state is tracked separately.
145  *
146  * Returns:
147  * True if @crtc is used, false otherwise.
148  */
149 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
150 {
151 	struct drm_encoder *encoder;
152 	struct drm_device *dev = crtc->dev;
153 
154 	/*
155 	 * We can expect this mutex to be locked if we are not panicking.
156 	 * Locking is currently fubar in the panic handler.
157 	 */
158 	if (!oops_in_progress)
159 		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
160 
161 	drm_for_each_encoder(encoder, dev)
162 		if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
163 			return true;
164 	return false;
165 }
166 EXPORT_SYMBOL(drm_helper_crtc_in_use);
167 
168 static void
169 drm_encoder_disable(struct drm_encoder *encoder)
170 {
171 	const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
172 
173 	if (!encoder_funcs)
174 		return;
175 
176 	drm_bridge_disable(encoder->bridge);
177 
178 	if (encoder_funcs->disable)
179 		(*encoder_funcs->disable)(encoder);
180 	else if (encoder_funcs->dpms)
181 		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
182 
183 	drm_bridge_post_disable(encoder->bridge);
184 }
185 
186 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
187 {
188 	struct drm_encoder *encoder;
189 	struct drm_crtc *crtc;
190 
191 	drm_warn_on_modeset_not_all_locked(dev);
192 
193 	drm_for_each_encoder(encoder, dev) {
194 		if (!drm_helper_encoder_in_use(encoder)) {
195 			drm_encoder_disable(encoder);
196 			/* disconnect encoder from any connector */
197 			encoder->crtc = NULL;
198 		}
199 	}
200 
201 	drm_for_each_crtc(crtc, dev) {
202 		const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
203 		crtc->enabled = drm_helper_crtc_in_use(crtc);
204 		if (!crtc->enabled) {
205 			if (crtc_funcs->disable)
206 				(*crtc_funcs->disable)(crtc);
207 			else
208 				(*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
209 			crtc->primary->fb = NULL;
210 		}
211 	}
212 }
213 
214 /**
215  * drm_helper_disable_unused_functions - disable unused objects
216  * @dev: DRM device
217  *
218  * This function walks through the entire mode setting configuration of @dev. It
219  * will remove any CRTC links of unused encoders and encoder links of
220  * disconnected connectors. Then it will disable all unused encoders and CRTCs
221  * either by calling their disable callback if available or by calling their
222  * dpms callback with DRM_MODE_DPMS_OFF.
223  *
224  * NOTE:
225  *
226  * This function is part of the legacy modeset helper library and will cause
227  * major confusion with atomic drivers. This is because atomic helpers guarantee
228  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
229  * on an enabled functions. drm_helper_disable_unused_functions() on the other
230  * hand throws such guarantees into the wind and calls disable hooks
231  * unconditionally on unused functions.
232  */
233 void drm_helper_disable_unused_functions(struct drm_device *dev)
234 {
235 	drm_modeset_lock_all(dev);
236 	__drm_helper_disable_unused_functions(dev);
237 	drm_modeset_unlock_all(dev);
238 }
239 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
240 
241 /*
242  * Check the CRTC we're going to map each output to vs. its current
243  * CRTC.  If they don't match, we have to disable the output and the CRTC
244  * since the driver will have to re-route things.
245  */
246 static void
247 drm_crtc_prepare_encoders(struct drm_device *dev)
248 {
249 	const struct drm_encoder_helper_funcs *encoder_funcs;
250 	struct drm_encoder *encoder;
251 
252 	drm_for_each_encoder(encoder, dev) {
253 		encoder_funcs = encoder->helper_private;
254 		if (!encoder_funcs)
255 			continue;
256 
257 		/* Disable unused encoders */
258 		if (encoder->crtc == NULL)
259 			drm_encoder_disable(encoder);
260 		/* Disable encoders whose CRTC is about to change */
261 		if (encoder_funcs->get_crtc &&
262 		    encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
263 			drm_encoder_disable(encoder);
264 	}
265 }
266 
267 /**
268  * drm_crtc_helper_set_mode - internal helper to set a mode
269  * @crtc: CRTC to program
270  * @mode: mode to use
271  * @x: horizontal offset into the surface
272  * @y: vertical offset into the surface
273  * @old_fb: old framebuffer, for cleanup
274  *
275  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
276  * to fixup or reject the mode prior to trying to set it. This is an internal
277  * helper that drivers could e.g. use to update properties that require the
278  * entire output pipe to be disabled and re-enabled in a new configuration. For
279  * example for changing whether audio is enabled on a hdmi link or for changing
280  * panel fitter or dither attributes. It is also called by the
281  * drm_crtc_helper_set_config() helper function to drive the mode setting
282  * sequence.
283  *
284  * Returns:
285  * True if the mode was set successfully, false otherwise.
286  */
287 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
288 			      struct drm_display_mode *mode,
289 			      int x, int y,
290 			      struct drm_framebuffer *old_fb)
291 {
292 	struct drm_device *dev = crtc->dev;
293 	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
294 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
295 	const struct drm_encoder_helper_funcs *encoder_funcs;
296 	int saved_x, saved_y;
297 	bool saved_enabled;
298 	struct drm_encoder *encoder;
299 	bool ret = true;
300 
301 	drm_warn_on_modeset_not_all_locked(dev);
302 
303 	saved_enabled = crtc->enabled;
304 	crtc->enabled = drm_helper_crtc_in_use(crtc);
305 	if (!crtc->enabled)
306 		return true;
307 
308 	adjusted_mode = drm_mode_duplicate(dev, mode);
309 	if (!adjusted_mode) {
310 		crtc->enabled = saved_enabled;
311 		return false;
312 	}
313 
314 	saved_mode = crtc->mode;
315 	saved_hwmode = crtc->hwmode;
316 	saved_x = crtc->x;
317 	saved_y = crtc->y;
318 
319 	/* Update crtc values up front so the driver can rely on them for mode
320 	 * setting.
321 	 */
322 	crtc->mode = *mode;
323 	crtc->x = x;
324 	crtc->y = y;
325 
326 	/* Pass our mode to the connectors and the CRTC to give them a chance to
327 	 * adjust it according to limitations or connector properties, and also
328 	 * a chance to reject the mode entirely.
329 	 */
330 	drm_for_each_encoder(encoder, dev) {
331 
332 		if (encoder->crtc != crtc)
333 			continue;
334 
335 		encoder_funcs = encoder->helper_private;
336 		if (!encoder_funcs)
337 			continue;
338 
339 		ret = drm_bridge_mode_fixup(encoder->bridge,
340 			mode, adjusted_mode);
341 		if (!ret) {
342 			DRM_DEBUG_KMS("Bridge fixup failed\n");
343 			goto done;
344 		}
345 
346 		encoder_funcs = encoder->helper_private;
347 		if (encoder_funcs->mode_fixup) {
348 			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
349 							      adjusted_mode))) {
350 				DRM_DEBUG_KMS("Encoder fixup failed\n");
351 				goto done;
352 			}
353 		}
354 	}
355 
356 	if (crtc_funcs->mode_fixup) {
357 		if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
358 						adjusted_mode))) {
359 			DRM_DEBUG_KMS("CRTC fixup failed\n");
360 			goto done;
361 		}
362 	}
363 	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
364 
365 	crtc->hwmode = *adjusted_mode;
366 
367 	/* Prepare the encoders and CRTCs before setting the mode. */
368 	drm_for_each_encoder(encoder, dev) {
369 
370 		if (encoder->crtc != crtc)
371 			continue;
372 
373 		encoder_funcs = encoder->helper_private;
374 		if (!encoder_funcs)
375 			continue;
376 
377 		drm_bridge_disable(encoder->bridge);
378 
379 		/* Disable the encoders as the first thing we do. */
380 		if (encoder_funcs->prepare)
381 			encoder_funcs->prepare(encoder);
382 
383 		drm_bridge_post_disable(encoder->bridge);
384 	}
385 
386 	drm_crtc_prepare_encoders(dev);
387 
388 	crtc_funcs->prepare(crtc);
389 
390 	/* Set up the DPLL and any encoders state that needs to adjust or depend
391 	 * on the DPLL.
392 	 */
393 	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
394 	if (!ret)
395 	    goto done;
396 
397 	drm_for_each_encoder(encoder, dev) {
398 
399 		if (encoder->crtc != crtc)
400 			continue;
401 
402 		encoder_funcs = encoder->helper_private;
403 		if (!encoder_funcs)
404 			continue;
405 
406 		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
407 			encoder->base.id, encoder->name,
408 			mode->base.id, mode->name);
409 		if (encoder_funcs->mode_set)
410 			encoder_funcs->mode_set(encoder, mode, adjusted_mode);
411 
412 		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
413 	}
414 
415 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
416 	crtc_funcs->commit(crtc);
417 
418 	drm_for_each_encoder(encoder, dev) {
419 
420 		if (encoder->crtc != crtc)
421 			continue;
422 
423 		encoder_funcs = encoder->helper_private;
424 		if (!encoder_funcs)
425 			continue;
426 
427 		drm_bridge_pre_enable(encoder->bridge);
428 
429 		if (encoder_funcs->commit)
430 			encoder_funcs->commit(encoder);
431 
432 		drm_bridge_enable(encoder->bridge);
433 	}
434 
435 	/* Calculate and store various constants which
436 	 * are later needed by vblank and swap-completion
437 	 * timestamping. They are derived from true hwmode.
438 	 */
439 	drm_calc_timestamping_constants(crtc, &crtc->hwmode);
440 
441 	/* FIXME: add subpixel order */
442 done:
443 	drm_mode_destroy(dev, adjusted_mode);
444 	if (!ret) {
445 		crtc->enabled = saved_enabled;
446 		crtc->mode = saved_mode;
447 		crtc->hwmode = saved_hwmode;
448 		crtc->x = saved_x;
449 		crtc->y = saved_y;
450 	}
451 
452 	return ret;
453 }
454 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
455 
456 static void
457 drm_crtc_helper_disable(struct drm_crtc *crtc)
458 {
459 	struct drm_device *dev = crtc->dev;
460 	struct drm_connector *connector;
461 	struct drm_encoder *encoder;
462 
463 	/* Decouple all encoders and their attached connectors from this crtc */
464 	drm_for_each_encoder(encoder, dev) {
465 		if (encoder->crtc != crtc)
466 			continue;
467 
468 		drm_for_each_connector(connector, dev) {
469 			if (connector->encoder != encoder)
470 				continue;
471 
472 			connector->encoder = NULL;
473 
474 			/*
475 			 * drm_helper_disable_unused_functions() ought to be
476 			 * doing this, but since we've decoupled the encoder
477 			 * from the connector above, the required connection
478 			 * between them is henceforth no longer available.
479 			 */
480 			connector->dpms = DRM_MODE_DPMS_OFF;
481 
482 			/* we keep a reference while the encoder is bound */
483 			drm_connector_unreference(connector);
484 		}
485 	}
486 
487 	__drm_helper_disable_unused_functions(dev);
488 }
489 
490 /**
491  * drm_crtc_helper_set_config - set a new config from userspace
492  * @set: mode set configuration
493  *
494  * The drm_crtc_helper_set_config() helper function implements the set_config
495  * callback of struct &drm_crtc_funcs for drivers using the legacy CRTC helpers.
496  *
497  * It first tries to locate the best encoder for each connector by calling the
498  * connector ->best_encoder() (struct &drm_connector_helper_funcs) helper
499  * operation.
500  *
501  * After locating the appropriate encoders, the helper function will call the
502  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
503  * or reject it completely in which case an error will be returned to the
504  * application. If the new configuration after mode adjustment is identical to
505  * the current configuration the helper function will return without performing
506  * any other operation.
507  *
508  * If the adjusted mode is identical to the current mode but changes to the
509  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
510  * will call the CRTC ->mode_set_base() (struct &drm_crtc_helper_funcs) helper
511  * operation.
512  *
513  * If the adjusted mode differs from the current mode, or if the
514  * ->mode_set_base() helper operation is not provided, the helper function
515  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
516  * and ->commit() CRTC and encoder helper operations, in that order.
517  * Alternatively it can also use the dpms and disable helper operations. For
518  * details see struct &drm_crtc_helper_funcs and struct
519  * &drm_encoder_helper_funcs.
520  *
521  * This function is deprecated.  New drivers must implement atomic modeset
522  * support, for which this function is unsuitable. Instead drivers should use
523  * drm_atomic_helper_set_config().
524  *
525  * Returns:
526  * Returns 0 on success, negative errno numbers on failure.
527  */
528 int drm_crtc_helper_set_config(struct drm_mode_set *set)
529 {
530 	struct drm_device *dev;
531 	struct drm_crtc **save_encoder_crtcs, *new_crtc;
532 	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
533 	bool mode_changed = false; /* if true do a full mode set */
534 	bool fb_changed = false; /* if true and !mode_changed just do a flip */
535 	struct drm_connector *connector;
536 	int count = 0, ro, fail = 0;
537 	const struct drm_crtc_helper_funcs *crtc_funcs;
538 	struct drm_mode_set save_set;
539 	int ret;
540 	int i;
541 
542 	DRM_DEBUG_KMS("\n");
543 
544 	BUG_ON(!set);
545 	BUG_ON(!set->crtc);
546 	BUG_ON(!set->crtc->helper_private);
547 
548 	/* Enforce sane interface api - has been abused by the fb helper. */
549 	BUG_ON(!set->mode && set->fb);
550 	BUG_ON(set->fb && set->num_connectors == 0);
551 
552 	crtc_funcs = set->crtc->helper_private;
553 
554 	if (!set->mode)
555 		set->fb = NULL;
556 
557 	if (set->fb) {
558 		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
559 			      set->crtc->base.id, set->crtc->name,
560 			      set->fb->base.id,
561 			      (int)set->num_connectors, set->x, set->y);
562 	} else {
563 		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
564 			      set->crtc->base.id, set->crtc->name);
565 		drm_crtc_helper_disable(set->crtc);
566 		return 0;
567 	}
568 
569 	dev = set->crtc->dev;
570 
571 	drm_warn_on_modeset_not_all_locked(dev);
572 
573 	/*
574 	 * Allocate space for the backup of all (non-pointer) encoder and
575 	 * connector data.
576 	 */
577 	save_encoder_crtcs = kzalloc(dev->mode_config.num_encoder *
578 				sizeof(struct drm_crtc *), GFP_KERNEL);
579 	if (!save_encoder_crtcs)
580 		return -ENOMEM;
581 
582 	save_connector_encoders = kzalloc(dev->mode_config.num_connector *
583 				sizeof(struct drm_encoder *), GFP_KERNEL);
584 	if (!save_connector_encoders) {
585 		kfree(save_encoder_crtcs);
586 		return -ENOMEM;
587 	}
588 
589 	/*
590 	 * Copy data. Note that driver private data is not affected.
591 	 * Should anything bad happen only the expected state is
592 	 * restored, not the drivers personal bookkeeping.
593 	 */
594 	count = 0;
595 	drm_for_each_encoder(encoder, dev) {
596 		save_encoder_crtcs[count++] = encoder->crtc;
597 	}
598 
599 	count = 0;
600 	drm_for_each_connector(connector, dev) {
601 		save_connector_encoders[count++] = connector->encoder;
602 	}
603 
604 	save_set.crtc = set->crtc;
605 	save_set.mode = &set->crtc->mode;
606 	save_set.x = set->crtc->x;
607 	save_set.y = set->crtc->y;
608 	save_set.fb = set->crtc->primary->fb;
609 
610 	/* We should be able to check here if the fb has the same properties
611 	 * and then just flip_or_move it */
612 	if (set->crtc->primary->fb != set->fb) {
613 		/* If we have no fb then treat it as a full mode set */
614 		if (set->crtc->primary->fb == NULL) {
615 			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
616 			mode_changed = true;
617 		} else if (set->fb->pixel_format !=
618 			   set->crtc->primary->fb->pixel_format) {
619 			mode_changed = true;
620 		} else
621 			fb_changed = true;
622 	}
623 
624 	if (set->x != set->crtc->x || set->y != set->crtc->y)
625 		fb_changed = true;
626 
627 	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
628 		DRM_DEBUG_KMS("modes are different, full mode set\n");
629 		drm_mode_debug_printmodeline(&set->crtc->mode);
630 		drm_mode_debug_printmodeline(set->mode);
631 		mode_changed = true;
632 	}
633 
634 	/* take a reference on all unbound connectors in set, reuse the
635 	 * already taken reference for bound connectors
636 	 */
637 	for (ro = 0; ro < set->num_connectors; ro++) {
638 		if (set->connectors[ro]->encoder)
639 			continue;
640 		drm_connector_reference(set->connectors[ro]);
641 	}
642 
643 	/* a) traverse passed in connector list and get encoders for them */
644 	count = 0;
645 	drm_for_each_connector(connector, dev) {
646 		const struct drm_connector_helper_funcs *connector_funcs =
647 			connector->helper_private;
648 		new_encoder = connector->encoder;
649 		for (ro = 0; ro < set->num_connectors; ro++) {
650 			if (set->connectors[ro] == connector) {
651 				new_encoder = connector_funcs->best_encoder(connector);
652 				/* if we can't get an encoder for a connector
653 				   we are setting now - then fail */
654 				if (new_encoder == NULL)
655 					/* don't break so fail path works correct */
656 					fail = 1;
657 
658 				if (connector->dpms != DRM_MODE_DPMS_ON) {
659 					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
660 					mode_changed = true;
661 				}
662 
663 				break;
664 			}
665 		}
666 
667 		if (new_encoder != connector->encoder) {
668 			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
669 			mode_changed = true;
670 			/* If the encoder is reused for another connector, then
671 			 * the appropriate crtc will be set later.
672 			 */
673 			if (connector->encoder)
674 				connector->encoder->crtc = NULL;
675 			connector->encoder = new_encoder;
676 		}
677 	}
678 
679 	if (fail) {
680 		ret = -EINVAL;
681 		goto fail;
682 	}
683 
684 	count = 0;
685 	drm_for_each_connector(connector, dev) {
686 		if (!connector->encoder)
687 			continue;
688 
689 		if (connector->encoder->crtc == set->crtc)
690 			new_crtc = NULL;
691 		else
692 			new_crtc = connector->encoder->crtc;
693 
694 		for (ro = 0; ro < set->num_connectors; ro++) {
695 			if (set->connectors[ro] == connector)
696 				new_crtc = set->crtc;
697 		}
698 
699 		/* Make sure the new CRTC will work with the encoder */
700 		if (new_crtc &&
701 		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
702 			ret = -EINVAL;
703 			goto fail;
704 		}
705 		if (new_crtc != connector->encoder->crtc) {
706 			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
707 			mode_changed = true;
708 			connector->encoder->crtc = new_crtc;
709 		}
710 		if (new_crtc) {
711 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
712 				      connector->base.id, connector->name,
713 				      new_crtc->base.id, new_crtc->name);
714 		} else {
715 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
716 				      connector->base.id, connector->name);
717 		}
718 	}
719 
720 	/* mode_set_base is not a required function */
721 	if (fb_changed && !crtc_funcs->mode_set_base)
722 		mode_changed = true;
723 
724 	if (mode_changed) {
725 		if (drm_helper_crtc_in_use(set->crtc)) {
726 			DRM_DEBUG_KMS("attempting to set mode from"
727 					" userspace\n");
728 			drm_mode_debug_printmodeline(set->mode);
729 			set->crtc->primary->fb = set->fb;
730 			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
731 						      set->x, set->y,
732 						      save_set.fb)) {
733 				DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
734 					  set->crtc->base.id, set->crtc->name);
735 				set->crtc->primary->fb = save_set.fb;
736 				ret = -EINVAL;
737 				goto fail;
738 			}
739 			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
740 			for (i = 0; i < set->num_connectors; i++) {
741 				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
742 					      set->connectors[i]->name);
743 				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
744 			}
745 		}
746 		__drm_helper_disable_unused_functions(dev);
747 	} else if (fb_changed) {
748 		set->crtc->x = set->x;
749 		set->crtc->y = set->y;
750 		set->crtc->primary->fb = set->fb;
751 		ret = crtc_funcs->mode_set_base(set->crtc,
752 						set->x, set->y, save_set.fb);
753 		if (ret != 0) {
754 			set->crtc->x = save_set.x;
755 			set->crtc->y = save_set.y;
756 			set->crtc->primary->fb = save_set.fb;
757 			goto fail;
758 		}
759 	}
760 
761 	kfree(save_connector_encoders);
762 	kfree(save_encoder_crtcs);
763 	return 0;
764 
765 fail:
766 	/* Restore all previous data. */
767 	count = 0;
768 	drm_for_each_encoder(encoder, dev) {
769 		encoder->crtc = save_encoder_crtcs[count++];
770 	}
771 
772 	count = 0;
773 	drm_for_each_connector(connector, dev) {
774 		connector->encoder = save_connector_encoders[count++];
775 	}
776 
777 	/* after fail drop reference on all unbound connectors in set, let
778 	 * bound connectors keep their reference
779 	 */
780 	for (ro = 0; ro < set->num_connectors; ro++) {
781 		if (set->connectors[ro]->encoder)
782 			continue;
783 		drm_connector_unreference(set->connectors[ro]);
784 	}
785 
786 	/* Try to restore the config */
787 	if (mode_changed &&
788 	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
789 				      save_set.y, save_set.fb))
790 		DRM_ERROR("failed to restore config after modeset failure\n");
791 
792 	kfree(save_connector_encoders);
793 	kfree(save_encoder_crtcs);
794 	return ret;
795 }
796 EXPORT_SYMBOL(drm_crtc_helper_set_config);
797 
798 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
799 {
800 	int dpms = DRM_MODE_DPMS_OFF;
801 	struct drm_connector *connector;
802 	struct drm_device *dev = encoder->dev;
803 
804 	drm_for_each_connector(connector, dev)
805 		if (connector->encoder == encoder)
806 			if (connector->dpms < dpms)
807 				dpms = connector->dpms;
808 	return dpms;
809 }
810 
811 /* Helper which handles bridge ordering around encoder dpms */
812 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
813 {
814 	struct drm_bridge *bridge = encoder->bridge;
815 	const struct drm_encoder_helper_funcs *encoder_funcs;
816 
817 	encoder_funcs = encoder->helper_private;
818 	if (!encoder_funcs)
819 		return;
820 
821 	if (mode == DRM_MODE_DPMS_ON)
822 		drm_bridge_pre_enable(bridge);
823 	else
824 		drm_bridge_disable(bridge);
825 
826 	if (encoder_funcs->dpms)
827 		encoder_funcs->dpms(encoder, mode);
828 
829 	if (mode == DRM_MODE_DPMS_ON)
830 		drm_bridge_enable(bridge);
831 	else
832 		drm_bridge_post_disable(bridge);
833 }
834 
835 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
836 {
837 	int dpms = DRM_MODE_DPMS_OFF;
838 	struct drm_connector *connector;
839 	struct drm_device *dev = crtc->dev;
840 
841 	drm_for_each_connector(connector, dev)
842 		if (connector->encoder && connector->encoder->crtc == crtc)
843 			if (connector->dpms < dpms)
844 				dpms = connector->dpms;
845 	return dpms;
846 }
847 
848 /**
849  * drm_helper_connector_dpms() - connector dpms helper implementation
850  * @connector: affected connector
851  * @mode: DPMS mode
852  *
853  * The drm_helper_connector_dpms() helper function implements the ->dpms()
854  * callback of struct &drm_connector_funcs for drivers using the legacy CRTC helpers.
855  *
856  * This is the main helper function provided by the CRTC helper framework for
857  * implementing the DPMS connector attribute. It computes the new desired DPMS
858  * state for all encoders and CRTCs in the output mesh and calls the ->dpms()
859  * callbacks provided by the driver in struct &drm_crtc_helper_funcs and struct
860  * &drm_encoder_helper_funcs appropriately.
861  *
862  * This function is deprecated.  New drivers must implement atomic modeset
863  * support, for which this function is unsuitable. Instead drivers should use
864  * drm_atomic_helper_connector_dpms().
865  *
866  * Returns:
867  * Always returns 0.
868  */
869 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
870 {
871 	struct drm_encoder *encoder = connector->encoder;
872 	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
873 	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
874 
875 	if (mode == connector->dpms)
876 		return 0;
877 
878 	old_dpms = connector->dpms;
879 	connector->dpms = mode;
880 
881 	if (encoder)
882 		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
883 
884 	/* from off to on, do crtc then encoder */
885 	if (mode < old_dpms) {
886 		if (crtc) {
887 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
888 			if (crtc_funcs->dpms)
889 				(*crtc_funcs->dpms) (crtc,
890 						     drm_helper_choose_crtc_dpms(crtc));
891 		}
892 		if (encoder)
893 			drm_helper_encoder_dpms(encoder, encoder_dpms);
894 	}
895 
896 	/* from on to off, do encoder then crtc */
897 	if (mode > old_dpms) {
898 		if (encoder)
899 			drm_helper_encoder_dpms(encoder, encoder_dpms);
900 		if (crtc) {
901 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
902 			if (crtc_funcs->dpms)
903 				(*crtc_funcs->dpms) (crtc,
904 						     drm_helper_choose_crtc_dpms(crtc));
905 		}
906 	}
907 
908 	return 0;
909 }
910 EXPORT_SYMBOL(drm_helper_connector_dpms);
911 
912 /**
913  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
914  * @fb: drm_framebuffer object to fill out
915  * @mode_cmd: metadata from the userspace fb creation request
916  *
917  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
918  * metadata fields.
919  */
920 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
921 				    const struct drm_mode_fb_cmd2 *mode_cmd)
922 {
923 	int i;
924 
925 	fb->width = mode_cmd->width;
926 	fb->height = mode_cmd->height;
927 	for (i = 0; i < 4; i++) {
928 		fb->pitches[i] = mode_cmd->pitches[i];
929 		fb->offsets[i] = mode_cmd->offsets[i];
930 		fb->modifier[i] = mode_cmd->modifier[i];
931 	}
932 	drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
933 				    &fb->bits_per_pixel);
934 	fb->pixel_format = mode_cmd->pixel_format;
935 	fb->flags = mode_cmd->flags;
936 }
937 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
938 
939 /**
940  * drm_helper_resume_force_mode - force-restore mode setting configuration
941  * @dev: drm_device which should be restored
942  *
943  * Drivers which use the mode setting helpers can use this function to
944  * force-restore the mode setting configuration e.g. on resume or when something
945  * else might have trampled over the hw state (like some overzealous old BIOSen
946  * tended to do).
947  *
948  * This helper doesn't provide a error return value since restoring the old
949  * config should never fail due to resource allocation issues since the driver
950  * has successfully set the restored configuration already. Hence this should
951  * boil down to the equivalent of a few dpms on calls, which also don't provide
952  * an error code.
953  *
954  * Drivers where simply restoring an old configuration again might fail (e.g.
955  * due to slight differences in allocating shared resources when the
956  * configuration is restored in a different order than when userspace set it up)
957  * need to use their own restore logic.
958  *
959  * This function is deprecated. New drivers should implement atomic mode-
960  * setting and use the atomic suspend/resume helpers.
961  *
962  * See also:
963  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
964  */
965 void drm_helper_resume_force_mode(struct drm_device *dev)
966 {
967 	struct drm_crtc *crtc;
968 	struct drm_encoder *encoder;
969 	const struct drm_crtc_helper_funcs *crtc_funcs;
970 	int encoder_dpms;
971 	bool ret;
972 
973 	drm_modeset_lock_all(dev);
974 	drm_for_each_crtc(crtc, dev) {
975 
976 		if (!crtc->enabled)
977 			continue;
978 
979 		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
980 					       crtc->x, crtc->y, crtc->primary->fb);
981 
982 		/* Restoring the old config should never fail! */
983 		if (ret == false)
984 			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
985 
986 		/* Turn off outputs that were already powered off */
987 		if (drm_helper_choose_crtc_dpms(crtc)) {
988 			drm_for_each_encoder(encoder, dev) {
989 
990 				if(encoder->crtc != crtc)
991 					continue;
992 
993 				encoder_dpms = drm_helper_choose_encoder_dpms(
994 							encoder);
995 
996 				drm_helper_encoder_dpms(encoder, encoder_dpms);
997 			}
998 
999 			crtc_funcs = crtc->helper_private;
1000 			if (crtc_funcs->dpms)
1001 				(*crtc_funcs->dpms) (crtc,
1002 						     drm_helper_choose_crtc_dpms(crtc));
1003 		}
1004 	}
1005 
1006 	/* disable the unused connectors while restoring the modesetting */
1007 	__drm_helper_disable_unused_functions(dev);
1008 	drm_modeset_unlock_all(dev);
1009 }
1010 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1011 
1012 /**
1013  * drm_helper_crtc_mode_set - mode_set implementation for atomic plane helpers
1014  * @crtc: DRM CRTC
1015  * @mode: DRM display mode which userspace requested
1016  * @adjusted_mode: DRM display mode adjusted by ->mode_fixup callbacks
1017  * @x: x offset of the CRTC scanout area on the underlying framebuffer
1018  * @y: y offset of the CRTC scanout area on the underlying framebuffer
1019  * @old_fb: previous framebuffer
1020  *
1021  * This function implements a callback useable as the ->mode_set callback
1022  * required by the CRTC helpers. Besides the atomic plane helper functions for
1023  * the primary plane the driver must also provide the ->mode_set_nofb callback
1024  * to set up the CRTC.
1025  *
1026  * This is a transitional helper useful for converting drivers to the atomic
1027  * interfaces.
1028  */
1029 int drm_helper_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
1030 			     struct drm_display_mode *adjusted_mode, int x, int y,
1031 			     struct drm_framebuffer *old_fb)
1032 {
1033 	struct drm_crtc_state *crtc_state;
1034 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
1035 	int ret;
1036 
1037 	if (crtc->funcs->atomic_duplicate_state)
1038 		crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
1039 	else {
1040 		if (!crtc->state)
1041 			drm_atomic_helper_crtc_reset(crtc);
1042 
1043 		crtc_state = drm_atomic_helper_crtc_duplicate_state(crtc);
1044 	}
1045 
1046 	if (!crtc_state)
1047 		return -ENOMEM;
1048 
1049 	crtc_state->planes_changed = true;
1050 	crtc_state->mode_changed = true;
1051 	ret = drm_atomic_set_mode_for_crtc(crtc_state, mode);
1052 	if (ret)
1053 		goto out;
1054 	drm_mode_copy(&crtc_state->adjusted_mode, adjusted_mode);
1055 
1056 	if (crtc_funcs->atomic_check) {
1057 		ret = crtc_funcs->atomic_check(crtc, crtc_state);
1058 		if (ret)
1059 			goto out;
1060 	}
1061 
1062 	swap(crtc->state, crtc_state);
1063 
1064 	crtc_funcs->mode_set_nofb(crtc);
1065 
1066 	ret = drm_helper_crtc_mode_set_base(crtc, x, y, old_fb);
1067 
1068 out:
1069 	if (crtc_state) {
1070 		if (crtc->funcs->atomic_destroy_state)
1071 			crtc->funcs->atomic_destroy_state(crtc, crtc_state);
1072 		else
1073 			drm_atomic_helper_crtc_destroy_state(crtc, crtc_state);
1074 	}
1075 
1076 	return ret;
1077 }
1078 EXPORT_SYMBOL(drm_helper_crtc_mode_set);
1079 
1080 /**
1081  * drm_helper_crtc_mode_set_base - mode_set_base implementation for atomic plane helpers
1082  * @crtc: DRM CRTC
1083  * @x: x offset of the CRTC scanout area on the underlying framebuffer
1084  * @y: y offset of the CRTC scanout area on the underlying framebuffer
1085  * @old_fb: previous framebuffer
1086  *
1087  * This function implements a callback useable as the ->mode_set_base used
1088  * required by the CRTC helpers. The driver must provide the atomic plane helper
1089  * functions for the primary plane.
1090  *
1091  * This is a transitional helper useful for converting drivers to the atomic
1092  * interfaces.
1093  */
1094 int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
1095 				  struct drm_framebuffer *old_fb)
1096 {
1097 	struct drm_plane_state *plane_state;
1098 	struct drm_plane *plane = crtc->primary;
1099 
1100 	if (plane->funcs->atomic_duplicate_state)
1101 		plane_state = plane->funcs->atomic_duplicate_state(plane);
1102 	else {
1103 		if (!plane->state)
1104 			drm_atomic_helper_plane_reset(plane);
1105 
1106 		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
1107 	}
1108 	if (!plane_state)
1109 		return -ENOMEM;
1110 	plane_state->plane = plane;
1111 
1112 	plane_state->crtc = crtc;
1113 	drm_atomic_set_fb_for_plane(plane_state, crtc->primary->fb);
1114 	plane_state->crtc_x = 0;
1115 	plane_state->crtc_y = 0;
1116 	plane_state->crtc_h = crtc->mode.vdisplay;
1117 	plane_state->crtc_w = crtc->mode.hdisplay;
1118 	plane_state->src_x = x << 16;
1119 	plane_state->src_y = y << 16;
1120 	plane_state->src_h = crtc->mode.vdisplay << 16;
1121 	plane_state->src_w = crtc->mode.hdisplay << 16;
1122 
1123 	return drm_plane_helper_commit(plane, plane_state, old_fb);
1124 }
1125 EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
1126 
1127 /**
1128  * drm_helper_crtc_enable_color_mgmt - enable color management properties
1129  * @crtc: DRM CRTC
1130  * @degamma_lut_size: the size of the degamma lut (before CSC)
1131  * @gamma_lut_size: the size of the gamma lut (after CSC)
1132  *
1133  * This function lets the driver enable the color correction properties on a
1134  * CRTC. This includes 3 degamma, csc and gamma properties that userspace can
1135  * set and 2 size properties to inform the userspace of the lut sizes.
1136  */
1137 void drm_helper_crtc_enable_color_mgmt(struct drm_crtc *crtc,
1138 				       int degamma_lut_size,
1139 				       int gamma_lut_size)
1140 {
1141 	struct drm_device *dev = crtc->dev;
1142 	struct drm_mode_config *config = &dev->mode_config;
1143 
1144 	drm_object_attach_property(&crtc->base,
1145 				   config->degamma_lut_property, 0);
1146 	drm_object_attach_property(&crtc->base,
1147 				   config->ctm_property, 0);
1148 	drm_object_attach_property(&crtc->base,
1149 				   config->gamma_lut_property, 0);
1150 
1151 	drm_object_attach_property(&crtc->base,
1152 				   config->degamma_lut_size_property,
1153 				   degamma_lut_size);
1154 	drm_object_attach_property(&crtc->base,
1155 				   config->gamma_lut_size_property,
1156 				   gamma_lut_size);
1157 }
1158 EXPORT_SYMBOL(drm_helper_crtc_enable_color_mgmt);
1159