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