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 	if (drm_core_check_feature(dev, DRIVER_ATOMIC))
236 		DRM_ERROR("Called for atomic driver, this is not what you want.\n");
237 
238 	drm_modeset_lock_all(dev);
239 	__drm_helper_disable_unused_functions(dev);
240 	drm_modeset_unlock_all(dev);
241 }
242 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
243 
244 /*
245  * Check the CRTC we're going to map each output to vs. its current
246  * CRTC.  If they don't match, we have to disable the output and the CRTC
247  * since the driver will have to re-route things.
248  */
249 static void
250 drm_crtc_prepare_encoders(struct drm_device *dev)
251 {
252 	const struct drm_encoder_helper_funcs *encoder_funcs;
253 	struct drm_encoder *encoder;
254 
255 	drm_for_each_encoder(encoder, dev) {
256 		encoder_funcs = encoder->helper_private;
257 		if (!encoder_funcs)
258 			continue;
259 
260 		/* Disable unused encoders */
261 		if (encoder->crtc == NULL)
262 			drm_encoder_disable(encoder);
263 		/* Disable encoders whose CRTC is about to change */
264 		if (encoder_funcs->get_crtc &&
265 		    encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
266 			drm_encoder_disable(encoder);
267 	}
268 }
269 
270 /**
271  * drm_crtc_helper_set_mode - internal helper to set a mode
272  * @crtc: CRTC to program
273  * @mode: mode to use
274  * @x: horizontal offset into the surface
275  * @y: vertical offset into the surface
276  * @old_fb: old framebuffer, for cleanup
277  *
278  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
279  * to fixup or reject the mode prior to trying to set it. This is an internal
280  * helper that drivers could e.g. use to update properties that require the
281  * entire output pipe to be disabled and re-enabled in a new configuration. For
282  * example for changing whether audio is enabled on a hdmi link or for changing
283  * panel fitter or dither attributes. It is also called by the
284  * drm_crtc_helper_set_config() helper function to drive the mode setting
285  * sequence.
286  *
287  * Returns:
288  * True if the mode was set successfully, false otherwise.
289  */
290 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
291 			      struct drm_display_mode *mode,
292 			      int x, int y,
293 			      struct drm_framebuffer *old_fb)
294 {
295 	struct drm_device *dev = crtc->dev;
296 	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
297 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
298 	const struct drm_encoder_helper_funcs *encoder_funcs;
299 	int saved_x, saved_y;
300 	bool saved_enabled;
301 	struct drm_encoder *encoder;
302 	bool ret = true;
303 
304 	drm_warn_on_modeset_not_all_locked(dev);
305 
306 	saved_enabled = crtc->enabled;
307 	crtc->enabled = drm_helper_crtc_in_use(crtc);
308 	if (!crtc->enabled)
309 		return true;
310 
311 	adjusted_mode = drm_mode_duplicate(dev, mode);
312 	if (!adjusted_mode) {
313 		crtc->enabled = saved_enabled;
314 		return false;
315 	}
316 
317 	saved_mode = crtc->mode;
318 	saved_hwmode = crtc->hwmode;
319 	saved_x = crtc->x;
320 	saved_y = crtc->y;
321 
322 	/* Update crtc values up front so the driver can rely on them for mode
323 	 * setting.
324 	 */
325 	crtc->mode = *mode;
326 	crtc->x = x;
327 	crtc->y = y;
328 
329 	/* Pass our mode to the connectors and the CRTC to give them a chance to
330 	 * adjust it according to limitations or connector properties, and also
331 	 * a chance to reject the mode entirely.
332 	 */
333 	drm_for_each_encoder(encoder, dev) {
334 
335 		if (encoder->crtc != crtc)
336 			continue;
337 
338 		encoder_funcs = encoder->helper_private;
339 		if (!encoder_funcs)
340 			continue;
341 
342 		ret = drm_bridge_mode_fixup(encoder->bridge,
343 			mode, adjusted_mode);
344 		if (!ret) {
345 			DRM_DEBUG_KMS("Bridge fixup failed\n");
346 			goto done;
347 		}
348 
349 		encoder_funcs = encoder->helper_private;
350 		if (encoder_funcs->mode_fixup) {
351 			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
352 							      adjusted_mode))) {
353 				DRM_DEBUG_KMS("Encoder fixup failed\n");
354 				goto done;
355 			}
356 		}
357 	}
358 
359 	if (crtc_funcs->mode_fixup) {
360 		if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
361 						adjusted_mode))) {
362 			DRM_DEBUG_KMS("CRTC fixup failed\n");
363 			goto done;
364 		}
365 	}
366 	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
367 
368 	crtc->hwmode = *adjusted_mode;
369 
370 	/* Prepare the encoders and CRTCs before setting the mode. */
371 	drm_for_each_encoder(encoder, dev) {
372 
373 		if (encoder->crtc != crtc)
374 			continue;
375 
376 		encoder_funcs = encoder->helper_private;
377 		if (!encoder_funcs)
378 			continue;
379 
380 		drm_bridge_disable(encoder->bridge);
381 
382 		/* Disable the encoders as the first thing we do. */
383 		if (encoder_funcs->prepare)
384 			encoder_funcs->prepare(encoder);
385 
386 		drm_bridge_post_disable(encoder->bridge);
387 	}
388 
389 	drm_crtc_prepare_encoders(dev);
390 
391 	crtc_funcs->prepare(crtc);
392 
393 	/* Set up the DPLL and any encoders state that needs to adjust or depend
394 	 * on the DPLL.
395 	 */
396 	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
397 	if (!ret)
398 	    goto done;
399 
400 	drm_for_each_encoder(encoder, dev) {
401 
402 		if (encoder->crtc != crtc)
403 			continue;
404 
405 		encoder_funcs = encoder->helper_private;
406 		if (!encoder_funcs)
407 			continue;
408 
409 		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
410 			encoder->base.id, encoder->name,
411 			mode->base.id, mode->name);
412 		if (encoder_funcs->mode_set)
413 			encoder_funcs->mode_set(encoder, mode, adjusted_mode);
414 
415 		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
416 	}
417 
418 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
419 	crtc_funcs->commit(crtc);
420 
421 	drm_for_each_encoder(encoder, dev) {
422 
423 		if (encoder->crtc != crtc)
424 			continue;
425 
426 		encoder_funcs = encoder->helper_private;
427 		if (!encoder_funcs)
428 			continue;
429 
430 		drm_bridge_pre_enable(encoder->bridge);
431 
432 		if (encoder_funcs->commit)
433 			encoder_funcs->commit(encoder);
434 
435 		drm_bridge_enable(encoder->bridge);
436 	}
437 
438 	/* Calculate and store various constants which
439 	 * are later needed by vblank and swap-completion
440 	 * timestamping. They are derived from true hwmode.
441 	 */
442 	drm_calc_timestamping_constants(crtc, &crtc->hwmode);
443 
444 	/* FIXME: add subpixel order */
445 done:
446 	drm_mode_destroy(dev, adjusted_mode);
447 	if (!ret) {
448 		crtc->enabled = saved_enabled;
449 		crtc->mode = saved_mode;
450 		crtc->hwmode = saved_hwmode;
451 		crtc->x = saved_x;
452 		crtc->y = saved_y;
453 	}
454 
455 	return ret;
456 }
457 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
458 
459 static void
460 drm_crtc_helper_disable(struct drm_crtc *crtc)
461 {
462 	struct drm_device *dev = crtc->dev;
463 	struct drm_connector *connector;
464 	struct drm_encoder *encoder;
465 
466 	/* Decouple all encoders and their attached connectors from this crtc */
467 	drm_for_each_encoder(encoder, dev) {
468 		if (encoder->crtc != crtc)
469 			continue;
470 
471 		drm_for_each_connector(connector, dev) {
472 			if (connector->encoder != encoder)
473 				continue;
474 
475 			connector->encoder = NULL;
476 
477 			/*
478 			 * drm_helper_disable_unused_functions() ought to be
479 			 * doing this, but since we've decoupled the encoder
480 			 * from the connector above, the required connection
481 			 * between them is henceforth no longer available.
482 			 */
483 			connector->dpms = DRM_MODE_DPMS_OFF;
484 
485 			/* we keep a reference while the encoder is bound */
486 			drm_connector_unreference(connector);
487 		}
488 	}
489 
490 	__drm_helper_disable_unused_functions(dev);
491 }
492 
493 /**
494  * drm_crtc_helper_set_config - set a new config from userspace
495  * @set: mode set configuration
496  *
497  * The drm_crtc_helper_set_config() helper function implements the set_config
498  * callback of struct &drm_crtc_funcs for drivers using the legacy CRTC helpers.
499  *
500  * It first tries to locate the best encoder for each connector by calling the
501  * connector ->best_encoder() (struct &drm_connector_helper_funcs) helper
502  * operation.
503  *
504  * After locating the appropriate encoders, the helper function will call the
505  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
506  * or reject it completely in which case an error will be returned to the
507  * application. If the new configuration after mode adjustment is identical to
508  * the current configuration the helper function will return without performing
509  * any other operation.
510  *
511  * If the adjusted mode is identical to the current mode but changes to the
512  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
513  * will call the CRTC ->mode_set_base() (struct &drm_crtc_helper_funcs) helper
514  * operation.
515  *
516  * If the adjusted mode differs from the current mode, or if the
517  * ->mode_set_base() helper operation is not provided, the helper function
518  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
519  * and ->commit() CRTC and encoder helper operations, in that order.
520  * Alternatively it can also use the dpms and disable helper operations. For
521  * details see struct &drm_crtc_helper_funcs and struct
522  * &drm_encoder_helper_funcs.
523  *
524  * This function is deprecated.  New drivers must implement atomic modeset
525  * support, for which this function is unsuitable. Instead drivers should use
526  * drm_atomic_helper_set_config().
527  *
528  * Returns:
529  * Returns 0 on success, negative errno numbers on failure.
530  */
531 int drm_crtc_helper_set_config(struct drm_mode_set *set)
532 {
533 	struct drm_device *dev;
534 	struct drm_crtc **save_encoder_crtcs, *new_crtc;
535 	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
536 	bool mode_changed = false; /* if true do a full mode set */
537 	bool fb_changed = false; /* if true and !mode_changed just do a flip */
538 	struct drm_connector *connector;
539 	int count = 0, ro, fail = 0;
540 	const struct drm_crtc_helper_funcs *crtc_funcs;
541 	struct drm_mode_set save_set;
542 	int ret;
543 	int i;
544 
545 	DRM_DEBUG_KMS("\n");
546 
547 	BUG_ON(!set);
548 	BUG_ON(!set->crtc);
549 	BUG_ON(!set->crtc->helper_private);
550 
551 	/* Enforce sane interface api - has been abused by the fb helper. */
552 	BUG_ON(!set->mode && set->fb);
553 	BUG_ON(set->fb && set->num_connectors == 0);
554 
555 	crtc_funcs = set->crtc->helper_private;
556 
557 	if (!set->mode)
558 		set->fb = NULL;
559 
560 	if (set->fb) {
561 		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
562 			      set->crtc->base.id, set->crtc->name,
563 			      set->fb->base.id,
564 			      (int)set->num_connectors, set->x, set->y);
565 	} else {
566 		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
567 			      set->crtc->base.id, set->crtc->name);
568 		drm_crtc_helper_disable(set->crtc);
569 		return 0;
570 	}
571 
572 	dev = set->crtc->dev;
573 
574 	drm_warn_on_modeset_not_all_locked(dev);
575 
576 	/*
577 	 * Allocate space for the backup of all (non-pointer) encoder and
578 	 * connector data.
579 	 */
580 	save_encoder_crtcs = kzalloc(dev->mode_config.num_encoder *
581 				sizeof(struct drm_crtc *), GFP_KERNEL);
582 	if (!save_encoder_crtcs)
583 		return -ENOMEM;
584 
585 	save_connector_encoders = kzalloc(dev->mode_config.num_connector *
586 				sizeof(struct drm_encoder *), GFP_KERNEL);
587 	if (!save_connector_encoders) {
588 		kfree(save_encoder_crtcs);
589 		return -ENOMEM;
590 	}
591 
592 	/*
593 	 * Copy data. Note that driver private data is not affected.
594 	 * Should anything bad happen only the expected state is
595 	 * restored, not the drivers personal bookkeeping.
596 	 */
597 	count = 0;
598 	drm_for_each_encoder(encoder, dev) {
599 		save_encoder_crtcs[count++] = encoder->crtc;
600 	}
601 
602 	count = 0;
603 	drm_for_each_connector(connector, dev) {
604 		save_connector_encoders[count++] = connector->encoder;
605 	}
606 
607 	save_set.crtc = set->crtc;
608 	save_set.mode = &set->crtc->mode;
609 	save_set.x = set->crtc->x;
610 	save_set.y = set->crtc->y;
611 	save_set.fb = set->crtc->primary->fb;
612 
613 	/* We should be able to check here if the fb has the same properties
614 	 * and then just flip_or_move it */
615 	if (set->crtc->primary->fb != set->fb) {
616 		/* If we have no fb then treat it as a full mode set */
617 		if (set->crtc->primary->fb == NULL) {
618 			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
619 			mode_changed = true;
620 		} else if (set->fb->pixel_format !=
621 			   set->crtc->primary->fb->pixel_format) {
622 			mode_changed = true;
623 		} else
624 			fb_changed = true;
625 	}
626 
627 	if (set->x != set->crtc->x || set->y != set->crtc->y)
628 		fb_changed = true;
629 
630 	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
631 		DRM_DEBUG_KMS("modes are different, full mode set\n");
632 		drm_mode_debug_printmodeline(&set->crtc->mode);
633 		drm_mode_debug_printmodeline(set->mode);
634 		mode_changed = true;
635 	}
636 
637 	/* take a reference on all unbound connectors in set, reuse the
638 	 * already taken reference for bound connectors
639 	 */
640 	for (ro = 0; ro < set->num_connectors; ro++) {
641 		if (set->connectors[ro]->encoder)
642 			continue;
643 		drm_connector_reference(set->connectors[ro]);
644 	}
645 
646 	/* a) traverse passed in connector list and get encoders for them */
647 	count = 0;
648 	drm_for_each_connector(connector, dev) {
649 		const struct drm_connector_helper_funcs *connector_funcs =
650 			connector->helper_private;
651 		new_encoder = connector->encoder;
652 		for (ro = 0; ro < set->num_connectors; ro++) {
653 			if (set->connectors[ro] == connector) {
654 				new_encoder = connector_funcs->best_encoder(connector);
655 				/* if we can't get an encoder for a connector
656 				   we are setting now - then fail */
657 				if (new_encoder == NULL)
658 					/* don't break so fail path works correct */
659 					fail = 1;
660 
661 				if (connector->dpms != DRM_MODE_DPMS_ON) {
662 					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
663 					mode_changed = true;
664 				}
665 
666 				break;
667 			}
668 		}
669 
670 		if (new_encoder != connector->encoder) {
671 			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
672 			mode_changed = true;
673 			/* If the encoder is reused for another connector, then
674 			 * the appropriate crtc will be set later.
675 			 */
676 			if (connector->encoder)
677 				connector->encoder->crtc = NULL;
678 			connector->encoder = new_encoder;
679 		}
680 	}
681 
682 	if (fail) {
683 		ret = -EINVAL;
684 		goto fail;
685 	}
686 
687 	count = 0;
688 	drm_for_each_connector(connector, dev) {
689 		if (!connector->encoder)
690 			continue;
691 
692 		if (connector->encoder->crtc == set->crtc)
693 			new_crtc = NULL;
694 		else
695 			new_crtc = connector->encoder->crtc;
696 
697 		for (ro = 0; ro < set->num_connectors; ro++) {
698 			if (set->connectors[ro] == connector)
699 				new_crtc = set->crtc;
700 		}
701 
702 		/* Make sure the new CRTC will work with the encoder */
703 		if (new_crtc &&
704 		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
705 			ret = -EINVAL;
706 			goto fail;
707 		}
708 		if (new_crtc != connector->encoder->crtc) {
709 			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
710 			mode_changed = true;
711 			connector->encoder->crtc = new_crtc;
712 		}
713 		if (new_crtc) {
714 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
715 				      connector->base.id, connector->name,
716 				      new_crtc->base.id, new_crtc->name);
717 		} else {
718 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
719 				      connector->base.id, connector->name);
720 		}
721 	}
722 
723 	/* mode_set_base is not a required function */
724 	if (fb_changed && !crtc_funcs->mode_set_base)
725 		mode_changed = true;
726 
727 	if (mode_changed) {
728 		if (drm_helper_crtc_in_use(set->crtc)) {
729 			DRM_DEBUG_KMS("attempting to set mode from"
730 					" userspace\n");
731 			drm_mode_debug_printmodeline(set->mode);
732 			set->crtc->primary->fb = set->fb;
733 			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
734 						      set->x, set->y,
735 						      save_set.fb)) {
736 				DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
737 					  set->crtc->base.id, set->crtc->name);
738 				set->crtc->primary->fb = save_set.fb;
739 				ret = -EINVAL;
740 				goto fail;
741 			}
742 			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
743 			for (i = 0; i < set->num_connectors; i++) {
744 				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
745 					      set->connectors[i]->name);
746 				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
747 			}
748 		}
749 		__drm_helper_disable_unused_functions(dev);
750 	} else if (fb_changed) {
751 		set->crtc->x = set->x;
752 		set->crtc->y = set->y;
753 		set->crtc->primary->fb = set->fb;
754 		ret = crtc_funcs->mode_set_base(set->crtc,
755 						set->x, set->y, save_set.fb);
756 		if (ret != 0) {
757 			set->crtc->x = save_set.x;
758 			set->crtc->y = save_set.y;
759 			set->crtc->primary->fb = save_set.fb;
760 			goto fail;
761 		}
762 	}
763 
764 	kfree(save_connector_encoders);
765 	kfree(save_encoder_crtcs);
766 	return 0;
767 
768 fail:
769 	/* Restore all previous data. */
770 	count = 0;
771 	drm_for_each_encoder(encoder, dev) {
772 		encoder->crtc = save_encoder_crtcs[count++];
773 	}
774 
775 	count = 0;
776 	drm_for_each_connector(connector, dev) {
777 		connector->encoder = save_connector_encoders[count++];
778 	}
779 
780 	/* after fail drop reference on all unbound connectors in set, let
781 	 * bound connectors keep their reference
782 	 */
783 	for (ro = 0; ro < set->num_connectors; ro++) {
784 		if (set->connectors[ro]->encoder)
785 			continue;
786 		drm_connector_unreference(set->connectors[ro]);
787 	}
788 
789 	/* Try to restore the config */
790 	if (mode_changed &&
791 	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
792 				      save_set.y, save_set.fb))
793 		DRM_ERROR("failed to restore config after modeset failure\n");
794 
795 	kfree(save_connector_encoders);
796 	kfree(save_encoder_crtcs);
797 	return ret;
798 }
799 EXPORT_SYMBOL(drm_crtc_helper_set_config);
800 
801 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
802 {
803 	int dpms = DRM_MODE_DPMS_OFF;
804 	struct drm_connector *connector;
805 	struct drm_device *dev = encoder->dev;
806 
807 	drm_for_each_connector(connector, dev)
808 		if (connector->encoder == encoder)
809 			if (connector->dpms < dpms)
810 				dpms = connector->dpms;
811 	return dpms;
812 }
813 
814 /* Helper which handles bridge ordering around encoder dpms */
815 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
816 {
817 	struct drm_bridge *bridge = encoder->bridge;
818 	const struct drm_encoder_helper_funcs *encoder_funcs;
819 
820 	encoder_funcs = encoder->helper_private;
821 	if (!encoder_funcs)
822 		return;
823 
824 	if (mode == DRM_MODE_DPMS_ON)
825 		drm_bridge_pre_enable(bridge);
826 	else
827 		drm_bridge_disable(bridge);
828 
829 	if (encoder_funcs->dpms)
830 		encoder_funcs->dpms(encoder, mode);
831 
832 	if (mode == DRM_MODE_DPMS_ON)
833 		drm_bridge_enable(bridge);
834 	else
835 		drm_bridge_post_disable(bridge);
836 }
837 
838 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
839 {
840 	int dpms = DRM_MODE_DPMS_OFF;
841 	struct drm_connector *connector;
842 	struct drm_device *dev = crtc->dev;
843 
844 	drm_for_each_connector(connector, dev)
845 		if (connector->encoder && connector->encoder->crtc == crtc)
846 			if (connector->dpms < dpms)
847 				dpms = connector->dpms;
848 	return dpms;
849 }
850 
851 /**
852  * drm_helper_connector_dpms() - connector dpms helper implementation
853  * @connector: affected connector
854  * @mode: DPMS mode
855  *
856  * The drm_helper_connector_dpms() helper function implements the ->dpms()
857  * callback of struct &drm_connector_funcs for drivers using the legacy CRTC helpers.
858  *
859  * This is the main helper function provided by the CRTC helper framework for
860  * implementing the DPMS connector attribute. It computes the new desired DPMS
861  * state for all encoders and CRTCs in the output mesh and calls the ->dpms()
862  * callbacks provided by the driver in struct &drm_crtc_helper_funcs and struct
863  * &drm_encoder_helper_funcs appropriately.
864  *
865  * This function is deprecated.  New drivers must implement atomic modeset
866  * support, for which this function is unsuitable. Instead drivers should use
867  * drm_atomic_helper_connector_dpms().
868  *
869  * Returns:
870  * Always returns 0.
871  */
872 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
873 {
874 	struct drm_encoder *encoder = connector->encoder;
875 	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
876 	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
877 
878 	if (mode == connector->dpms)
879 		return 0;
880 
881 	old_dpms = connector->dpms;
882 	connector->dpms = mode;
883 
884 	if (encoder)
885 		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
886 
887 	/* from off to on, do crtc then encoder */
888 	if (mode < old_dpms) {
889 		if (crtc) {
890 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
891 			if (crtc_funcs->dpms)
892 				(*crtc_funcs->dpms) (crtc,
893 						     drm_helper_choose_crtc_dpms(crtc));
894 		}
895 		if (encoder)
896 			drm_helper_encoder_dpms(encoder, encoder_dpms);
897 	}
898 
899 	/* from on to off, do encoder then crtc */
900 	if (mode > old_dpms) {
901 		if (encoder)
902 			drm_helper_encoder_dpms(encoder, encoder_dpms);
903 		if (crtc) {
904 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
905 			if (crtc_funcs->dpms)
906 				(*crtc_funcs->dpms) (crtc,
907 						     drm_helper_choose_crtc_dpms(crtc));
908 		}
909 	}
910 
911 	return 0;
912 }
913 EXPORT_SYMBOL(drm_helper_connector_dpms);
914 
915 /**
916  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
917  * @fb: drm_framebuffer object to fill out
918  * @mode_cmd: metadata from the userspace fb creation request
919  *
920  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
921  * metadata fields.
922  */
923 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
924 				    const struct drm_mode_fb_cmd2 *mode_cmd)
925 {
926 	int i;
927 
928 	fb->width = mode_cmd->width;
929 	fb->height = mode_cmd->height;
930 	for (i = 0; i < 4; i++) {
931 		fb->pitches[i] = mode_cmd->pitches[i];
932 		fb->offsets[i] = mode_cmd->offsets[i];
933 		fb->modifier[i] = mode_cmd->modifier[i];
934 	}
935 	drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
936 				    &fb->bits_per_pixel);
937 	fb->pixel_format = mode_cmd->pixel_format;
938 	fb->flags = mode_cmd->flags;
939 }
940 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
941 
942 /**
943  * drm_helper_resume_force_mode - force-restore mode setting configuration
944  * @dev: drm_device which should be restored
945  *
946  * Drivers which use the mode setting helpers can use this function to
947  * force-restore the mode setting configuration e.g. on resume or when something
948  * else might have trampled over the hw state (like some overzealous old BIOSen
949  * tended to do).
950  *
951  * This helper doesn't provide a error return value since restoring the old
952  * config should never fail due to resource allocation issues since the driver
953  * has successfully set the restored configuration already. Hence this should
954  * boil down to the equivalent of a few dpms on calls, which also don't provide
955  * an error code.
956  *
957  * Drivers where simply restoring an old configuration again might fail (e.g.
958  * due to slight differences in allocating shared resources when the
959  * configuration is restored in a different order than when userspace set it up)
960  * need to use their own restore logic.
961  *
962  * This function is deprecated. New drivers should implement atomic mode-
963  * setting and use the atomic suspend/resume helpers.
964  *
965  * See also:
966  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
967  */
968 void drm_helper_resume_force_mode(struct drm_device *dev)
969 {
970 	struct drm_crtc *crtc;
971 	struct drm_encoder *encoder;
972 	const struct drm_crtc_helper_funcs *crtc_funcs;
973 	int encoder_dpms;
974 	bool ret;
975 
976 	drm_modeset_lock_all(dev);
977 	drm_for_each_crtc(crtc, dev) {
978 
979 		if (!crtc->enabled)
980 			continue;
981 
982 		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
983 					       crtc->x, crtc->y, crtc->primary->fb);
984 
985 		/* Restoring the old config should never fail! */
986 		if (ret == false)
987 			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
988 
989 		/* Turn off outputs that were already powered off */
990 		if (drm_helper_choose_crtc_dpms(crtc)) {
991 			drm_for_each_encoder(encoder, dev) {
992 
993 				if(encoder->crtc != crtc)
994 					continue;
995 
996 				encoder_dpms = drm_helper_choose_encoder_dpms(
997 							encoder);
998 
999 				drm_helper_encoder_dpms(encoder, encoder_dpms);
1000 			}
1001 
1002 			crtc_funcs = crtc->helper_private;
1003 			if (crtc_funcs->dpms)
1004 				(*crtc_funcs->dpms) (crtc,
1005 						     drm_helper_choose_crtc_dpms(crtc));
1006 		}
1007 	}
1008 
1009 	/* disable the unused connectors while restoring the modesetting */
1010 	__drm_helper_disable_unused_functions(dev);
1011 	drm_modeset_unlock_all(dev);
1012 }
1013 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1014 
1015 /**
1016  * drm_helper_crtc_mode_set - mode_set implementation for atomic plane helpers
1017  * @crtc: DRM CRTC
1018  * @mode: DRM display mode which userspace requested
1019  * @adjusted_mode: DRM display mode adjusted by ->mode_fixup callbacks
1020  * @x: x offset of the CRTC scanout area on the underlying framebuffer
1021  * @y: y offset of the CRTC scanout area on the underlying framebuffer
1022  * @old_fb: previous framebuffer
1023  *
1024  * This function implements a callback useable as the ->mode_set callback
1025  * required by the CRTC helpers. Besides the atomic plane helper functions for
1026  * the primary plane the driver must also provide the ->mode_set_nofb callback
1027  * to set up the CRTC.
1028  *
1029  * This is a transitional helper useful for converting drivers to the atomic
1030  * interfaces.
1031  */
1032 int drm_helper_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
1033 			     struct drm_display_mode *adjusted_mode, int x, int y,
1034 			     struct drm_framebuffer *old_fb)
1035 {
1036 	struct drm_crtc_state *crtc_state;
1037 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
1038 	int ret;
1039 
1040 	if (crtc->funcs->atomic_duplicate_state)
1041 		crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
1042 	else {
1043 		if (!crtc->state)
1044 			drm_atomic_helper_crtc_reset(crtc);
1045 
1046 		crtc_state = drm_atomic_helper_crtc_duplicate_state(crtc);
1047 	}
1048 
1049 	if (!crtc_state)
1050 		return -ENOMEM;
1051 
1052 	crtc_state->planes_changed = true;
1053 	crtc_state->mode_changed = true;
1054 	ret = drm_atomic_set_mode_for_crtc(crtc_state, mode);
1055 	if (ret)
1056 		goto out;
1057 	drm_mode_copy(&crtc_state->adjusted_mode, adjusted_mode);
1058 
1059 	if (crtc_funcs->atomic_check) {
1060 		ret = crtc_funcs->atomic_check(crtc, crtc_state);
1061 		if (ret)
1062 			goto out;
1063 	}
1064 
1065 	swap(crtc->state, crtc_state);
1066 
1067 	crtc_funcs->mode_set_nofb(crtc);
1068 
1069 	ret = drm_helper_crtc_mode_set_base(crtc, x, y, old_fb);
1070 
1071 out:
1072 	if (crtc_state) {
1073 		if (crtc->funcs->atomic_destroy_state)
1074 			crtc->funcs->atomic_destroy_state(crtc, crtc_state);
1075 		else
1076 			drm_atomic_helper_crtc_destroy_state(crtc, crtc_state);
1077 	}
1078 
1079 	return ret;
1080 }
1081 EXPORT_SYMBOL(drm_helper_crtc_mode_set);
1082 
1083 /**
1084  * drm_helper_crtc_mode_set_base - mode_set_base implementation for atomic plane helpers
1085  * @crtc: DRM CRTC
1086  * @x: x offset of the CRTC scanout area on the underlying framebuffer
1087  * @y: y offset of the CRTC scanout area on the underlying framebuffer
1088  * @old_fb: previous framebuffer
1089  *
1090  * This function implements a callback useable as the ->mode_set_base used
1091  * required by the CRTC helpers. The driver must provide the atomic plane helper
1092  * functions for the primary plane.
1093  *
1094  * This is a transitional helper useful for converting drivers to the atomic
1095  * interfaces.
1096  */
1097 int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
1098 				  struct drm_framebuffer *old_fb)
1099 {
1100 	struct drm_plane_state *plane_state;
1101 	struct drm_plane *plane = crtc->primary;
1102 
1103 	if (plane->funcs->atomic_duplicate_state)
1104 		plane_state = plane->funcs->atomic_duplicate_state(plane);
1105 	else {
1106 		if (!plane->state)
1107 			drm_atomic_helper_plane_reset(plane);
1108 
1109 		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
1110 	}
1111 	if (!plane_state)
1112 		return -ENOMEM;
1113 	plane_state->plane = plane;
1114 
1115 	plane_state->crtc = crtc;
1116 	drm_atomic_set_fb_for_plane(plane_state, crtc->primary->fb);
1117 	plane_state->crtc_x = 0;
1118 	plane_state->crtc_y = 0;
1119 	plane_state->crtc_h = crtc->mode.vdisplay;
1120 	plane_state->crtc_w = crtc->mode.hdisplay;
1121 	plane_state->src_x = x << 16;
1122 	plane_state->src_y = y << 16;
1123 	plane_state->src_h = crtc->mode.vdisplay << 16;
1124 	plane_state->src_w = crtc->mode.hdisplay << 16;
1125 
1126 	return drm_plane_helper_commit(plane, plane_state, old_fb);
1127 }
1128 EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
1129