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_begin(dev, &conn_iter);
106 	drm_for_each_connector_iter(connector, &conn_iter) {
107 		if (connector->encoder == encoder) {
108 			drm_connector_list_iter_end(&conn_iter);
109 			return true;
110 		}
111 	}
112 	drm_connector_list_iter_end(&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_begin(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_put(connector);
469 		}
470 		drm_connector_list_iter_end(&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  * @ctx: lock acquire context, not used here
480  *
481  * The drm_crtc_helper_set_config() helper function implements the of
482  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
483  * helpers.
484  *
485  * It first tries to locate the best encoder for each connector by calling the
486  * connector @drm_connector_helper_funcs.best_encoder helper operation.
487  *
488  * After locating the appropriate encoders, the helper function will call the
489  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
490  * or reject it completely in which case an error will be returned to the
491  * application. If the new configuration after mode adjustment is identical to
492  * the current configuration the helper function will return without performing
493  * any other operation.
494  *
495  * If the adjusted mode is identical to the current mode but changes to the
496  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
497  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
498  *
499  * If the adjusted mode differs from the current mode, or if the
500  * ->mode_set_base() helper operation is not provided, the helper function
501  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
502  * and ->commit() CRTC and encoder helper operations, in that order.
503  * Alternatively it can also use the dpms and disable helper operations. For
504  * details see &struct drm_crtc_helper_funcs and struct
505  * &drm_encoder_helper_funcs.
506  *
507  * This function is deprecated.  New drivers must implement atomic modeset
508  * support, for which this function is unsuitable. Instead drivers should use
509  * drm_atomic_helper_set_config().
510  *
511  * Returns:
512  * Returns 0 on success, negative errno numbers on failure.
513  */
514 int drm_crtc_helper_set_config(struct drm_mode_set *set,
515 			       struct drm_modeset_acquire_ctx *ctx)
516 {
517 	struct drm_device *dev;
518 	struct drm_crtc **save_encoder_crtcs, *new_crtc;
519 	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
520 	bool mode_changed = false; /* if true do a full mode set */
521 	bool fb_changed = false; /* if true and !mode_changed just do a flip */
522 	struct drm_connector *connector;
523 	struct drm_connector_list_iter conn_iter;
524 	int count = 0, ro, fail = 0;
525 	const struct drm_crtc_helper_funcs *crtc_funcs;
526 	struct drm_mode_set save_set;
527 	int ret;
528 	int i;
529 
530 	DRM_DEBUG_KMS("\n");
531 
532 	BUG_ON(!set);
533 	BUG_ON(!set->crtc);
534 	BUG_ON(!set->crtc->helper_private);
535 
536 	/* Enforce sane interface api - has been abused by the fb helper. */
537 	BUG_ON(!set->mode && set->fb);
538 	BUG_ON(set->fb && set->num_connectors == 0);
539 
540 	crtc_funcs = set->crtc->helper_private;
541 
542 	if (!set->mode)
543 		set->fb = NULL;
544 
545 	if (set->fb) {
546 		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
547 			      set->crtc->base.id, set->crtc->name,
548 			      set->fb->base.id,
549 			      (int)set->num_connectors, set->x, set->y);
550 	} else {
551 		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
552 			      set->crtc->base.id, set->crtc->name);
553 		drm_crtc_helper_disable(set->crtc);
554 		return 0;
555 	}
556 
557 	dev = set->crtc->dev;
558 
559 	drm_warn_on_modeset_not_all_locked(dev);
560 
561 	/*
562 	 * Allocate space for the backup of all (non-pointer) encoder and
563 	 * connector data.
564 	 */
565 	save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
566 				sizeof(struct drm_crtc *), GFP_KERNEL);
567 	if (!save_encoder_crtcs)
568 		return -ENOMEM;
569 
570 	save_connector_encoders = kcalloc(dev->mode_config.num_connector,
571 				sizeof(struct drm_encoder *), GFP_KERNEL);
572 	if (!save_connector_encoders) {
573 		kfree(save_encoder_crtcs);
574 		return -ENOMEM;
575 	}
576 
577 	/*
578 	 * Copy data. Note that driver private data is not affected.
579 	 * Should anything bad happen only the expected state is
580 	 * restored, not the drivers personal bookkeeping.
581 	 */
582 	count = 0;
583 	drm_for_each_encoder(encoder, dev) {
584 		save_encoder_crtcs[count++] = encoder->crtc;
585 	}
586 
587 	count = 0;
588 	drm_connector_list_iter_begin(dev, &conn_iter);
589 	drm_for_each_connector_iter(connector, &conn_iter)
590 		save_connector_encoders[count++] = connector->encoder;
591 	drm_connector_list_iter_end(&conn_iter);
592 
593 	save_set.crtc = set->crtc;
594 	save_set.mode = &set->crtc->mode;
595 	save_set.x = set->crtc->x;
596 	save_set.y = set->crtc->y;
597 	save_set.fb = set->crtc->primary->fb;
598 
599 	/* We should be able to check here if the fb has the same properties
600 	 * and then just flip_or_move it */
601 	if (set->crtc->primary->fb != set->fb) {
602 		/* If we have no fb then treat it as a full mode set */
603 		if (set->crtc->primary->fb == NULL) {
604 			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
605 			mode_changed = true;
606 		} else if (set->fb->format != set->crtc->primary->fb->format) {
607 			mode_changed = true;
608 		} else
609 			fb_changed = true;
610 	}
611 
612 	if (set->x != set->crtc->x || set->y != set->crtc->y)
613 		fb_changed = true;
614 
615 	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
616 		DRM_DEBUG_KMS("modes are different, full mode set\n");
617 		drm_mode_debug_printmodeline(&set->crtc->mode);
618 		drm_mode_debug_printmodeline(set->mode);
619 		mode_changed = true;
620 	}
621 
622 	/* take a reference on all unbound connectors in set, reuse the
623 	 * already taken reference for bound connectors
624 	 */
625 	for (ro = 0; ro < set->num_connectors; ro++) {
626 		if (set->connectors[ro]->encoder)
627 			continue;
628 		drm_connector_get(set->connectors[ro]);
629 	}
630 
631 	/* a) traverse passed in connector list and get encoders for them */
632 	count = 0;
633 	drm_connector_list_iter_begin(dev, &conn_iter);
634 	drm_for_each_connector_iter(connector, &conn_iter) {
635 		const struct drm_connector_helper_funcs *connector_funcs =
636 			connector->helper_private;
637 		new_encoder = connector->encoder;
638 		for (ro = 0; ro < set->num_connectors; ro++) {
639 			if (set->connectors[ro] == connector) {
640 				new_encoder = connector_funcs->best_encoder(connector);
641 				/* if we can't get an encoder for a connector
642 				   we are setting now - then fail */
643 				if (new_encoder == NULL)
644 					/* don't break so fail path works correct */
645 					fail = 1;
646 
647 				if (connector->dpms != DRM_MODE_DPMS_ON) {
648 					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
649 					mode_changed = true;
650 				}
651 
652 				break;
653 			}
654 		}
655 
656 		if (new_encoder != connector->encoder) {
657 			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
658 			mode_changed = true;
659 			/* If the encoder is reused for another connector, then
660 			 * the appropriate crtc will be set later.
661 			 */
662 			if (connector->encoder)
663 				connector->encoder->crtc = NULL;
664 			connector->encoder = new_encoder;
665 		}
666 	}
667 	drm_connector_list_iter_end(&conn_iter);
668 
669 	if (fail) {
670 		ret = -EINVAL;
671 		goto fail;
672 	}
673 
674 	count = 0;
675 	drm_connector_list_iter_begin(dev, &conn_iter);
676 	drm_for_each_connector_iter(connector, &conn_iter) {
677 		if (!connector->encoder)
678 			continue;
679 
680 		if (connector->encoder->crtc == set->crtc)
681 			new_crtc = NULL;
682 		else
683 			new_crtc = connector->encoder->crtc;
684 
685 		for (ro = 0; ro < set->num_connectors; ro++) {
686 			if (set->connectors[ro] == connector)
687 				new_crtc = set->crtc;
688 		}
689 
690 		/* Make sure the new CRTC will work with the encoder */
691 		if (new_crtc &&
692 		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
693 			ret = -EINVAL;
694 			drm_connector_list_iter_end(&conn_iter);
695 			goto fail;
696 		}
697 		if (new_crtc != connector->encoder->crtc) {
698 			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
699 			mode_changed = true;
700 			connector->encoder->crtc = new_crtc;
701 		}
702 		if (new_crtc) {
703 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
704 				      connector->base.id, connector->name,
705 				      new_crtc->base.id, new_crtc->name);
706 		} else {
707 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
708 				      connector->base.id, connector->name);
709 		}
710 	}
711 	drm_connector_list_iter_end(&conn_iter);
712 
713 	/* mode_set_base is not a required function */
714 	if (fb_changed && !crtc_funcs->mode_set_base)
715 		mode_changed = true;
716 
717 	if (mode_changed) {
718 		if (drm_helper_crtc_in_use(set->crtc)) {
719 			DRM_DEBUG_KMS("attempting to set mode from"
720 					" userspace\n");
721 			drm_mode_debug_printmodeline(set->mode);
722 			set->crtc->primary->fb = set->fb;
723 			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
724 						      set->x, set->y,
725 						      save_set.fb)) {
726 				DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
727 					  set->crtc->base.id, set->crtc->name);
728 				set->crtc->primary->fb = save_set.fb;
729 				ret = -EINVAL;
730 				goto fail;
731 			}
732 			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
733 			for (i = 0; i < set->num_connectors; i++) {
734 				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
735 					      set->connectors[i]->name);
736 				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
737 			}
738 		}
739 		__drm_helper_disable_unused_functions(dev);
740 	} else if (fb_changed) {
741 		set->crtc->x = set->x;
742 		set->crtc->y = set->y;
743 		set->crtc->primary->fb = set->fb;
744 		ret = crtc_funcs->mode_set_base(set->crtc,
745 						set->x, set->y, save_set.fb);
746 		if (ret != 0) {
747 			set->crtc->x = save_set.x;
748 			set->crtc->y = save_set.y;
749 			set->crtc->primary->fb = save_set.fb;
750 			goto fail;
751 		}
752 	}
753 
754 	kfree(save_connector_encoders);
755 	kfree(save_encoder_crtcs);
756 	return 0;
757 
758 fail:
759 	/* Restore all previous data. */
760 	count = 0;
761 	drm_for_each_encoder(encoder, dev) {
762 		encoder->crtc = save_encoder_crtcs[count++];
763 	}
764 
765 	count = 0;
766 	drm_connector_list_iter_begin(dev, &conn_iter);
767 	drm_for_each_connector_iter(connector, &conn_iter)
768 		connector->encoder = save_connector_encoders[count++];
769 	drm_connector_list_iter_end(&conn_iter);
770 
771 	/* after fail drop reference on all unbound connectors in set, let
772 	 * bound connectors keep their reference
773 	 */
774 	for (ro = 0; ro < set->num_connectors; ro++) {
775 		if (set->connectors[ro]->encoder)
776 			continue;
777 		drm_connector_put(set->connectors[ro]);
778 	}
779 
780 	/* Try to restore the config */
781 	if (mode_changed &&
782 	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
783 				      save_set.y, save_set.fb))
784 		DRM_ERROR("failed to restore config after modeset failure\n");
785 
786 	kfree(save_connector_encoders);
787 	kfree(save_encoder_crtcs);
788 	return ret;
789 }
790 EXPORT_SYMBOL(drm_crtc_helper_set_config);
791 
792 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
793 {
794 	int dpms = DRM_MODE_DPMS_OFF;
795 	struct drm_connector *connector;
796 	struct drm_connector_list_iter conn_iter;
797 	struct drm_device *dev = encoder->dev;
798 
799 	drm_connector_list_iter_begin(dev, &conn_iter);
800 	drm_for_each_connector_iter(connector, &conn_iter)
801 		if (connector->encoder == encoder)
802 			if (connector->dpms < dpms)
803 				dpms = connector->dpms;
804 	drm_connector_list_iter_end(&conn_iter);
805 
806 	return dpms;
807 }
808 
809 /* Helper which handles bridge ordering around encoder dpms */
810 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
811 {
812 	struct drm_bridge *bridge = encoder->bridge;
813 	const struct drm_encoder_helper_funcs *encoder_funcs;
814 
815 	encoder_funcs = encoder->helper_private;
816 	if (!encoder_funcs)
817 		return;
818 
819 	if (mode == DRM_MODE_DPMS_ON)
820 		drm_bridge_pre_enable(bridge);
821 	else
822 		drm_bridge_disable(bridge);
823 
824 	if (encoder_funcs->dpms)
825 		encoder_funcs->dpms(encoder, mode);
826 
827 	if (mode == DRM_MODE_DPMS_ON)
828 		drm_bridge_enable(bridge);
829 	else
830 		drm_bridge_post_disable(bridge);
831 }
832 
833 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
834 {
835 	int dpms = DRM_MODE_DPMS_OFF;
836 	struct drm_connector *connector;
837 	struct drm_connector_list_iter conn_iter;
838 	struct drm_device *dev = crtc->dev;
839 
840 	drm_connector_list_iter_begin(dev, &conn_iter);
841 	drm_for_each_connector_iter(connector, &conn_iter)
842 		if (connector->encoder && connector->encoder->crtc == crtc)
843 			if (connector->dpms < dpms)
844 				dpms = connector->dpms;
845 	drm_connector_list_iter_end(&conn_iter);
846 
847 	return dpms;
848 }
849 
850 /**
851  * drm_helper_connector_dpms() - connector dpms helper implementation
852  * @connector: affected connector
853  * @mode: DPMS mode
854  *
855  * The drm_helper_connector_dpms() helper function implements the
856  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
857  * 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
862  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
863  * provided by the driver.
864  *
865  * This function is deprecated.  New drivers must implement atomic modeset
866  * support, where DPMS is handled in the DRM core.
867  *
868  * Returns:
869  * Always returns 0.
870  */
871 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
872 {
873 	struct drm_encoder *encoder = connector->encoder;
874 	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
875 	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
876 
877 	if (mode == connector->dpms)
878 		return 0;
879 
880 	old_dpms = connector->dpms;
881 	connector->dpms = mode;
882 
883 	if (encoder)
884 		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
885 
886 	/* from off to on, do crtc then encoder */
887 	if (mode < old_dpms) {
888 		if (crtc) {
889 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
890 			if (crtc_funcs->dpms)
891 				(*crtc_funcs->dpms) (crtc,
892 						     drm_helper_choose_crtc_dpms(crtc));
893 		}
894 		if (encoder)
895 			drm_helper_encoder_dpms(encoder, encoder_dpms);
896 	}
897 
898 	/* from on to off, do encoder then crtc */
899 	if (mode > old_dpms) {
900 		if (encoder)
901 			drm_helper_encoder_dpms(encoder, encoder_dpms);
902 		if (crtc) {
903 			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
904 			if (crtc_funcs->dpms)
905 				(*crtc_funcs->dpms) (crtc,
906 						     drm_helper_choose_crtc_dpms(crtc));
907 		}
908 	}
909 
910 	return 0;
911 }
912 EXPORT_SYMBOL(drm_helper_connector_dpms);
913 
914 /**
915  * drm_helper_resume_force_mode - force-restore mode setting configuration
916  * @dev: drm_device which should be restored
917  *
918  * Drivers which use the mode setting helpers can use this function to
919  * force-restore the mode setting configuration e.g. on resume or when something
920  * else might have trampled over the hw state (like some overzealous old BIOSen
921  * tended to do).
922  *
923  * This helper doesn't provide a error return value since restoring the old
924  * config should never fail due to resource allocation issues since the driver
925  * has successfully set the restored configuration already. Hence this should
926  * boil down to the equivalent of a few dpms on calls, which also don't provide
927  * an error code.
928  *
929  * Drivers where simply restoring an old configuration again might fail (e.g.
930  * due to slight differences in allocating shared resources when the
931  * configuration is restored in a different order than when userspace set it up)
932  * need to use their own restore logic.
933  *
934  * This function is deprecated. New drivers should implement atomic mode-
935  * setting and use the atomic suspend/resume helpers.
936  *
937  * See also:
938  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
939  */
940 void drm_helper_resume_force_mode(struct drm_device *dev)
941 {
942 	struct drm_crtc *crtc;
943 	struct drm_encoder *encoder;
944 	const struct drm_crtc_helper_funcs *crtc_funcs;
945 	int encoder_dpms;
946 	bool ret;
947 
948 	drm_modeset_lock_all(dev);
949 	drm_for_each_crtc(crtc, dev) {
950 
951 		if (!crtc->enabled)
952 			continue;
953 
954 		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
955 					       crtc->x, crtc->y, crtc->primary->fb);
956 
957 		/* Restoring the old config should never fail! */
958 		if (ret == false)
959 			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
960 
961 		/* Turn off outputs that were already powered off */
962 		if (drm_helper_choose_crtc_dpms(crtc)) {
963 			drm_for_each_encoder(encoder, dev) {
964 
965 				if(encoder->crtc != crtc)
966 					continue;
967 
968 				encoder_dpms = drm_helper_choose_encoder_dpms(
969 							encoder);
970 
971 				drm_helper_encoder_dpms(encoder, encoder_dpms);
972 			}
973 
974 			crtc_funcs = crtc->helper_private;
975 			if (crtc_funcs->dpms)
976 				(*crtc_funcs->dpms) (crtc,
977 						     drm_helper_choose_crtc_dpms(crtc));
978 		}
979 	}
980 
981 	/* disable the unused connectors while restoring the modesetting */
982 	__drm_helper_disable_unused_functions(dev);
983 	drm_modeset_unlock_all(dev);
984 }
985 EXPORT_SYMBOL(drm_helper_resume_force_mode);
986 
987 /**
988  * drm_helper_crtc_mode_set - mode_set implementation for atomic plane helpers
989  * @crtc: DRM CRTC
990  * @mode: DRM display mode which userspace requested
991  * @adjusted_mode: DRM display mode adjusted by ->mode_fixup callbacks
992  * @x: x offset of the CRTC scanout area on the underlying framebuffer
993  * @y: y offset of the CRTC scanout area on the underlying framebuffer
994  * @old_fb: previous framebuffer
995  *
996  * This function implements a callback useable as the ->mode_set callback
997  * required by the CRTC helpers. Besides the atomic plane helper functions for
998  * the primary plane the driver must also provide the ->mode_set_nofb callback
999  * to set up the CRTC.
1000  *
1001  * This is a transitional helper useful for converting drivers to the atomic
1002  * interfaces.
1003  */
1004 int drm_helper_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode,
1005 			     struct drm_display_mode *adjusted_mode, int x, int y,
1006 			     struct drm_framebuffer *old_fb)
1007 {
1008 	struct drm_crtc_state *crtc_state;
1009 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
1010 	int ret;
1011 
1012 	if (crtc->funcs->atomic_duplicate_state)
1013 		crtc_state = crtc->funcs->atomic_duplicate_state(crtc);
1014 	else {
1015 		if (!crtc->state)
1016 			drm_atomic_helper_crtc_reset(crtc);
1017 
1018 		crtc_state = drm_atomic_helper_crtc_duplicate_state(crtc);
1019 	}
1020 
1021 	if (!crtc_state)
1022 		return -ENOMEM;
1023 
1024 	crtc_state->planes_changed = true;
1025 	crtc_state->mode_changed = true;
1026 	ret = drm_atomic_set_mode_for_crtc(crtc_state, mode);
1027 	if (ret)
1028 		goto out;
1029 	drm_mode_copy(&crtc_state->adjusted_mode, adjusted_mode);
1030 
1031 	if (crtc_funcs->atomic_check) {
1032 		ret = crtc_funcs->atomic_check(crtc, crtc_state);
1033 		if (ret)
1034 			goto out;
1035 	}
1036 
1037 	swap(crtc->state, crtc_state);
1038 
1039 	crtc_funcs->mode_set_nofb(crtc);
1040 
1041 	ret = drm_helper_crtc_mode_set_base(crtc, x, y, old_fb);
1042 
1043 out:
1044 	if (crtc_state) {
1045 		if (crtc->funcs->atomic_destroy_state)
1046 			crtc->funcs->atomic_destroy_state(crtc, crtc_state);
1047 		else
1048 			drm_atomic_helper_crtc_destroy_state(crtc, crtc_state);
1049 	}
1050 
1051 	return ret;
1052 }
1053 EXPORT_SYMBOL(drm_helper_crtc_mode_set);
1054 
1055 /**
1056  * drm_helper_crtc_mode_set_base - mode_set_base implementation for atomic plane helpers
1057  * @crtc: DRM CRTC
1058  * @x: x offset of the CRTC scanout area on the underlying framebuffer
1059  * @y: y offset of the CRTC scanout area on the underlying framebuffer
1060  * @old_fb: previous framebuffer
1061  *
1062  * This function implements a callback useable as the ->mode_set_base used
1063  * required by the CRTC helpers. The driver must provide the atomic plane helper
1064  * functions for the primary plane.
1065  *
1066  * This is a transitional helper useful for converting drivers to the atomic
1067  * interfaces.
1068  */
1069 int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
1070 				  struct drm_framebuffer *old_fb)
1071 {
1072 	struct drm_plane_state *plane_state;
1073 	struct drm_plane *plane = crtc->primary;
1074 
1075 	if (plane->funcs->atomic_duplicate_state)
1076 		plane_state = plane->funcs->atomic_duplicate_state(plane);
1077 	else {
1078 		if (!plane->state)
1079 			drm_atomic_helper_plane_reset(plane);
1080 
1081 		plane_state = drm_atomic_helper_plane_duplicate_state(plane);
1082 	}
1083 	if (!plane_state)
1084 		return -ENOMEM;
1085 	plane_state->plane = plane;
1086 
1087 	plane_state->crtc = crtc;
1088 	drm_atomic_set_fb_for_plane(plane_state, crtc->primary->fb);
1089 	plane_state->crtc_x = 0;
1090 	plane_state->crtc_y = 0;
1091 	plane_state->crtc_h = crtc->mode.vdisplay;
1092 	plane_state->crtc_w = crtc->mode.hdisplay;
1093 	plane_state->src_x = x << 16;
1094 	plane_state->src_y = y << 16;
1095 	plane_state->src_h = crtc->mode.vdisplay << 16;
1096 	plane_state->src_w = crtc->mode.hdisplay << 16;
1097 
1098 	return drm_plane_helper_commit(plane, plane_state, old_fb);
1099 }
1100 EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
1101