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/export.h>
33 #include <linux/kernel.h>
34 #include <linux/moduleparam.h>
35 
36 #include <drm/drm_atomic.h>
37 #include <drm/drm_atomic_helper.h>
38 #include <drm/drm_atomic_uapi.h>
39 #include <drm/drm_bridge.h>
40 #include <drm/drm_crtc.h>
41 #include <drm/drm_crtc_helper.h>
42 #include <drm/drm_drv.h>
43 #include <drm/drm_edid.h>
44 #include <drm/drm_encoder.h>
45 #include <drm/drm_fb_helper.h>
46 #include <drm/drm_fourcc.h>
47 #include <drm/drm_plane_helper.h>
48 #include <drm/drm_print.h>
49 #include <drm/drm_vblank.h>
50 
51 #include "drm_crtc_helper_internal.h"
52 
53 /**
54  * DOC: overview
55  *
56  * The CRTC modeset helper library provides a default set_config implementation
57  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
58  * the same callbacks which drivers can use to e.g. restore the modeset
59  * configuration on resume with drm_helper_resume_force_mode().
60  *
61  * Note that this helper library doesn't track the current power state of CRTCs
62  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
63  * though the hardware is already in the desired state. This deficiency has been
64  * fixed in the atomic helpers.
65  *
66  * The driver callbacks are mostly compatible with the atomic modeset helpers,
67  * except for the handling of the primary plane: Atomic helpers require that the
68  * primary plane is implemented as a real standalone plane and not directly tied
69  * to the CRTC state. For easier transition this library provides functions to
70  * implement the old semantics required by the CRTC helpers using the new plane
71  * and atomic helper callbacks.
72  *
73  * Drivers are strongly urged to convert to the atomic helpers (by way of first
74  * converting to the plane helpers). New drivers must not use these functions
75  * but need to implement the atomic interface instead, potentially using the
76  * atomic helpers for that.
77  *
78  * These legacy modeset helpers use the same function table structures as
79  * all other modesetting helpers. See the documentation for struct
80  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
81  * &drm_connector_helper_funcs.
82  */
83 
84 /**
85  * drm_helper_encoder_in_use - check if a given encoder is in use
86  * @encoder: encoder to check
87  *
88  * Checks whether @encoder is with the current mode setting output configuration
89  * in use by any connector. This doesn't mean that it is actually enabled since
90  * the DPMS state is tracked separately.
91  *
92  * Returns:
93  * True if @encoder is used, false otherwise.
94  */
95 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
96 {
97 	struct drm_connector *connector;
98 	struct drm_connector_list_iter conn_iter;
99 	struct drm_device *dev = encoder->dev;
100 
101 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
102 
103 	/*
104 	 * We can expect this mutex to be locked if we are not panicking.
105 	 * Locking is currently fubar in the panic handler.
106 	 */
107 	if (!oops_in_progress) {
108 		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
109 		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
110 	}
111 
112 
113 	drm_connector_list_iter_begin(dev, &conn_iter);
114 	drm_for_each_connector_iter(connector, &conn_iter) {
115 		if (connector->encoder == encoder) {
116 			drm_connector_list_iter_end(&conn_iter);
117 			return true;
118 		}
119 	}
120 	drm_connector_list_iter_end(&conn_iter);
121 	return false;
122 }
123 EXPORT_SYMBOL(drm_helper_encoder_in_use);
124 
125 /**
126  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
127  * @crtc: CRTC to check
128  *
129  * Checks whether @crtc is with the current mode setting output configuration
130  * in use by any connector. This doesn't mean that it is actually enabled since
131  * the DPMS state is tracked separately.
132  *
133  * Returns:
134  * True if @crtc is used, false otherwise.
135  */
136 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
137 {
138 	struct drm_encoder *encoder;
139 	struct drm_device *dev = crtc->dev;
140 
141 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
142 
143 	/*
144 	 * We can expect this mutex to be locked if we are not panicking.
145 	 * Locking is currently fubar in the panic handler.
146 	 */
147 	if (!oops_in_progress)
148 		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
149 
150 	drm_for_each_encoder(encoder, dev)
151 		if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
152 			return true;
153 	return false;
154 }
155 EXPORT_SYMBOL(drm_helper_crtc_in_use);
156 
157 static void
158 drm_encoder_disable(struct drm_encoder *encoder)
159 {
160 	const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
161 
162 	if (!encoder_funcs)
163 		return;
164 
165 	if (encoder_funcs->disable)
166 		(*encoder_funcs->disable)(encoder);
167 	else if (encoder_funcs->dpms)
168 		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
169 }
170 
171 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
172 {
173 	struct drm_encoder *encoder;
174 	struct drm_crtc *crtc;
175 
176 	drm_warn_on_modeset_not_all_locked(dev);
177 
178 	drm_for_each_encoder(encoder, dev) {
179 		if (!drm_helper_encoder_in_use(encoder)) {
180 			drm_encoder_disable(encoder);
181 			/* disconnect encoder from any connector */
182 			encoder->crtc = NULL;
183 		}
184 	}
185 
186 	drm_for_each_crtc(crtc, dev) {
187 		const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
188 		crtc->enabled = drm_helper_crtc_in_use(crtc);
189 		if (!crtc->enabled) {
190 			if (crtc_funcs->disable)
191 				(*crtc_funcs->disable)(crtc);
192 			else
193 				(*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
194 			crtc->primary->fb = NULL;
195 		}
196 	}
197 }
198 
199 /**
200  * drm_helper_disable_unused_functions - disable unused objects
201  * @dev: DRM device
202  *
203  * This function walks through the entire mode setting configuration of @dev. It
204  * will remove any CRTC links of unused encoders and encoder links of
205  * disconnected connectors. Then it will disable all unused encoders and CRTCs
206  * either by calling their disable callback if available or by calling their
207  * dpms callback with DRM_MODE_DPMS_OFF.
208  *
209  * NOTE:
210  *
211  * This function is part of the legacy modeset helper library and will cause
212  * major confusion with atomic drivers. This is because atomic helpers guarantee
213  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
214  * on an enabled functions. drm_helper_disable_unused_functions() on the other
215  * hand throws such guarantees into the wind and calls disable hooks
216  * unconditionally on unused functions.
217  */
218 void drm_helper_disable_unused_functions(struct drm_device *dev)
219 {
220 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
221 
222 	drm_modeset_lock_all(dev);
223 	__drm_helper_disable_unused_functions(dev);
224 	drm_modeset_unlock_all(dev);
225 }
226 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
227 
228 /*
229  * Check the CRTC we're going to map each output to vs. its current
230  * CRTC.  If they don't match, we have to disable the output and the CRTC
231  * since the driver will have to re-route things.
232  */
233 static void
234 drm_crtc_prepare_encoders(struct drm_device *dev)
235 {
236 	const struct drm_encoder_helper_funcs *encoder_funcs;
237 	struct drm_encoder *encoder;
238 
239 	drm_for_each_encoder(encoder, dev) {
240 		encoder_funcs = encoder->helper_private;
241 		if (!encoder_funcs)
242 			continue;
243 
244 		/* Disable unused encoders */
245 		if (encoder->crtc == NULL)
246 			drm_encoder_disable(encoder);
247 		/* Disable encoders whose CRTC is about to change */
248 		if (encoder_funcs->get_crtc &&
249 		    encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
250 			drm_encoder_disable(encoder);
251 	}
252 }
253 
254 /**
255  * drm_crtc_helper_set_mode - internal helper to set a mode
256  * @crtc: CRTC to program
257  * @mode: mode to use
258  * @x: horizontal offset into the surface
259  * @y: vertical offset into the surface
260  * @old_fb: old framebuffer, for cleanup
261  *
262  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
263  * to fixup or reject the mode prior to trying to set it. This is an internal
264  * helper that drivers could e.g. use to update properties that require the
265  * entire output pipe to be disabled and re-enabled in a new configuration. For
266  * example for changing whether audio is enabled on a hdmi link or for changing
267  * panel fitter or dither attributes. It is also called by the
268  * drm_crtc_helper_set_config() helper function to drive the mode setting
269  * sequence.
270  *
271  * Returns:
272  * True if the mode was set successfully, false otherwise.
273  */
274 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
275 			      struct drm_display_mode *mode,
276 			      int x, int y,
277 			      struct drm_framebuffer *old_fb)
278 {
279 	struct drm_device *dev = crtc->dev;
280 	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
281 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
282 	const struct drm_encoder_helper_funcs *encoder_funcs;
283 	int saved_x, saved_y;
284 	bool saved_enabled;
285 	struct drm_encoder *encoder;
286 	bool ret = true;
287 
288 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
289 
290 	drm_warn_on_modeset_not_all_locked(dev);
291 
292 	saved_enabled = crtc->enabled;
293 	crtc->enabled = drm_helper_crtc_in_use(crtc);
294 	if (!crtc->enabled)
295 		return true;
296 
297 	adjusted_mode = drm_mode_duplicate(dev, mode);
298 	if (!adjusted_mode) {
299 		crtc->enabled = saved_enabled;
300 		return false;
301 	}
302 
303 	saved_mode = crtc->mode;
304 	saved_hwmode = crtc->hwmode;
305 	saved_x = crtc->x;
306 	saved_y = crtc->y;
307 
308 	/* Update crtc values up front so the driver can rely on them for mode
309 	 * setting.
310 	 */
311 	crtc->mode = *mode;
312 	crtc->x = x;
313 	crtc->y = y;
314 
315 	/* Pass our mode to the connectors and the CRTC to give them a chance to
316 	 * adjust it according to limitations or connector properties, and also
317 	 * a chance to reject the mode entirely.
318 	 */
319 	drm_for_each_encoder(encoder, dev) {
320 
321 		if (encoder->crtc != crtc)
322 			continue;
323 
324 		encoder_funcs = encoder->helper_private;
325 		if (!encoder_funcs)
326 			continue;
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 		/* Disable the encoders as the first thing we do. */
360 		if (encoder_funcs->prepare)
361 			encoder_funcs->prepare(encoder);
362 	}
363 
364 	drm_crtc_prepare_encoders(dev);
365 
366 	crtc_funcs->prepare(crtc);
367 
368 	/* Set up the DPLL and any encoders state that needs to adjust or depend
369 	 * on the DPLL.
370 	 */
371 	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
372 	if (!ret)
373 	    goto done;
374 
375 	drm_for_each_encoder(encoder, dev) {
376 
377 		if (encoder->crtc != crtc)
378 			continue;
379 
380 		encoder_funcs = encoder->helper_private;
381 		if (!encoder_funcs)
382 			continue;
383 
384 		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
385 			encoder->base.id, encoder->name, mode->name);
386 		if (encoder_funcs->mode_set)
387 			encoder_funcs->mode_set(encoder, mode, adjusted_mode);
388 	}
389 
390 	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
391 	crtc_funcs->commit(crtc);
392 
393 	drm_for_each_encoder(encoder, dev) {
394 
395 		if (encoder->crtc != crtc)
396 			continue;
397 
398 		encoder_funcs = encoder->helper_private;
399 		if (!encoder_funcs)
400 			continue;
401 
402 		if (encoder_funcs->commit)
403 			encoder_funcs->commit(encoder);
404 	}
405 
406 	/* Calculate and store various constants which
407 	 * are later needed by vblank and swap-completion
408 	 * timestamping. They are derived from true hwmode.
409 	 */
410 	drm_calc_timestamping_constants(crtc, &crtc->hwmode);
411 
412 	/* FIXME: add subpixel order */
413 done:
414 	drm_mode_destroy(dev, adjusted_mode);
415 	if (!ret) {
416 		crtc->enabled = saved_enabled;
417 		crtc->mode = saved_mode;
418 		crtc->hwmode = saved_hwmode;
419 		crtc->x = saved_x;
420 		crtc->y = saved_y;
421 	}
422 
423 	return ret;
424 }
425 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
426 
427 static void
428 drm_crtc_helper_disable(struct drm_crtc *crtc)
429 {
430 	struct drm_device *dev = crtc->dev;
431 	struct drm_connector *connector;
432 	struct drm_encoder *encoder;
433 
434 	/* Decouple all encoders and their attached connectors from this crtc */
435 	drm_for_each_encoder(encoder, dev) {
436 		struct drm_connector_list_iter conn_iter;
437 
438 		if (encoder->crtc != crtc)
439 			continue;
440 
441 		drm_connector_list_iter_begin(dev, &conn_iter);
442 		drm_for_each_connector_iter(connector, &conn_iter) {
443 			if (connector->encoder != encoder)
444 				continue;
445 
446 			connector->encoder = NULL;
447 
448 			/*
449 			 * drm_helper_disable_unused_functions() ought to be
450 			 * doing this, but since we've decoupled the encoder
451 			 * from the connector above, the required connection
452 			 * between them is henceforth no longer available.
453 			 */
454 			connector->dpms = DRM_MODE_DPMS_OFF;
455 
456 			/* we keep a reference while the encoder is bound */
457 			drm_connector_put(connector);
458 		}
459 		drm_connector_list_iter_end(&conn_iter);
460 	}
461 
462 	__drm_helper_disable_unused_functions(dev);
463 }
464 
465 /*
466  * For connectors that support multiple encoders, either the
467  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
468  */
469 struct drm_encoder *
470 drm_connector_get_single_encoder(struct drm_connector *connector)
471 {
472 	struct drm_encoder *encoder;
473 
474 	WARN_ON(hweight32(connector->possible_encoders) > 1);
475 	drm_connector_for_each_possible_encoder(connector, encoder)
476 		return encoder;
477 
478 	return NULL;
479 }
480 
481 /**
482  * drm_crtc_helper_set_config - set a new config from userspace
483  * @set: mode set configuration
484  * @ctx: lock acquire context, not used here
485  *
486  * The drm_crtc_helper_set_config() helper function implements the of
487  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
488  * helpers.
489  *
490  * It first tries to locate the best encoder for each connector by calling the
491  * connector @drm_connector_helper_funcs.best_encoder helper operation.
492  *
493  * After locating the appropriate encoders, the helper function will call the
494  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
495  * or reject it completely in which case an error will be returned to the
496  * application. If the new configuration after mode adjustment is identical to
497  * the current configuration the helper function will return without performing
498  * any other operation.
499  *
500  * If the adjusted mode is identical to the current mode but changes to the
501  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
502  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
503  *
504  * If the adjusted mode differs from the current mode, or if the
505  * ->mode_set_base() helper operation is not provided, the helper function
506  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
507  * and ->commit() CRTC and encoder helper operations, in that order.
508  * Alternatively it can also use the dpms and disable helper operations. For
509  * details see &struct drm_crtc_helper_funcs and struct
510  * &drm_encoder_helper_funcs.
511  *
512  * This function is deprecated.  New drivers must implement atomic modeset
513  * support, for which this function is unsuitable. Instead drivers should use
514  * drm_atomic_helper_set_config().
515  *
516  * Returns:
517  * Returns 0 on success, negative errno numbers on failure.
518  */
519 int drm_crtc_helper_set_config(struct drm_mode_set *set,
520 			       struct drm_modeset_acquire_ctx *ctx)
521 {
522 	struct drm_device *dev;
523 	struct drm_crtc **save_encoder_crtcs, *new_crtc;
524 	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
525 	bool mode_changed = false; /* if true do a full mode set */
526 	bool fb_changed = false; /* if true and !mode_changed just do a flip */
527 	struct drm_connector *connector;
528 	struct drm_connector_list_iter conn_iter;
529 	int count = 0, ro, fail = 0;
530 	const struct drm_crtc_helper_funcs *crtc_funcs;
531 	struct drm_mode_set save_set;
532 	int ret;
533 	int i;
534 
535 	DRM_DEBUG_KMS("\n");
536 
537 	BUG_ON(!set);
538 	BUG_ON(!set->crtc);
539 	BUG_ON(!set->crtc->helper_private);
540 
541 	/* Enforce sane interface api - has been abused by the fb helper. */
542 	BUG_ON(!set->mode && set->fb);
543 	BUG_ON(set->fb && set->num_connectors == 0);
544 
545 	crtc_funcs = set->crtc->helper_private;
546 
547 	dev = set->crtc->dev;
548 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
549 
550 	if (!set->mode)
551 		set->fb = NULL;
552 
553 	if (set->fb) {
554 		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
555 			      set->crtc->base.id, set->crtc->name,
556 			      set->fb->base.id,
557 			      (int)set->num_connectors, set->x, set->y);
558 	} else {
559 		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
560 			      set->crtc->base.id, set->crtc->name);
561 		drm_crtc_helper_disable(set->crtc);
562 		return 0;
563 	}
564 
565 	drm_warn_on_modeset_not_all_locked(dev);
566 
567 	/*
568 	 * Allocate space for the backup of all (non-pointer) encoder and
569 	 * connector data.
570 	 */
571 	save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
572 				sizeof(struct drm_crtc *), GFP_KERNEL);
573 	if (!save_encoder_crtcs)
574 		return -ENOMEM;
575 
576 	save_connector_encoders = kcalloc(dev->mode_config.num_connector,
577 				sizeof(struct drm_encoder *), GFP_KERNEL);
578 	if (!save_connector_encoders) {
579 		kfree(save_encoder_crtcs);
580 		return -ENOMEM;
581 	}
582 
583 	/*
584 	 * Copy data. Note that driver private data is not affected.
585 	 * Should anything bad happen only the expected state is
586 	 * restored, not the drivers personal bookkeeping.
587 	 */
588 	count = 0;
589 	drm_for_each_encoder(encoder, dev) {
590 		save_encoder_crtcs[count++] = encoder->crtc;
591 	}
592 
593 	count = 0;
594 	drm_connector_list_iter_begin(dev, &conn_iter);
595 	drm_for_each_connector_iter(connector, &conn_iter)
596 		save_connector_encoders[count++] = connector->encoder;
597 	drm_connector_list_iter_end(&conn_iter);
598 
599 	save_set.crtc = set->crtc;
600 	save_set.mode = &set->crtc->mode;
601 	save_set.x = set->crtc->x;
602 	save_set.y = set->crtc->y;
603 	save_set.fb = set->crtc->primary->fb;
604 
605 	/* We should be able to check here if the fb has the same properties
606 	 * and then just flip_or_move it */
607 	if (set->crtc->primary->fb != set->fb) {
608 		/* If we have no fb then treat it as a full mode set */
609 		if (set->crtc->primary->fb == NULL) {
610 			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
611 			mode_changed = true;
612 		} else if (set->fb->format != set->crtc->primary->fb->format) {
613 			mode_changed = true;
614 		} else
615 			fb_changed = true;
616 	}
617 
618 	if (set->x != set->crtc->x || set->y != set->crtc->y)
619 		fb_changed = true;
620 
621 	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
622 		DRM_DEBUG_KMS("modes are different, full mode set\n");
623 		drm_mode_debug_printmodeline(&set->crtc->mode);
624 		drm_mode_debug_printmodeline(set->mode);
625 		mode_changed = true;
626 	}
627 
628 	/* take a reference on all unbound connectors in set, reuse the
629 	 * already taken reference for bound connectors
630 	 */
631 	for (ro = 0; ro < set->num_connectors; ro++) {
632 		if (set->connectors[ro]->encoder)
633 			continue;
634 		drm_connector_get(set->connectors[ro]);
635 	}
636 
637 	/* a) traverse passed in connector list and get encoders for them */
638 	count = 0;
639 	drm_connector_list_iter_begin(dev, &conn_iter);
640 	drm_for_each_connector_iter(connector, &conn_iter) {
641 		const struct drm_connector_helper_funcs *connector_funcs =
642 			connector->helper_private;
643 		new_encoder = connector->encoder;
644 		for (ro = 0; ro < set->num_connectors; ro++) {
645 			if (set->connectors[ro] == connector) {
646 				if (connector_funcs->best_encoder)
647 					new_encoder = connector_funcs->best_encoder(connector);
648 				else
649 					new_encoder = drm_connector_get_single_encoder(connector);
650 
651 				/* if we can't get an encoder for a connector
652 				   we are setting now - then fail */
653 				if (new_encoder == NULL)
654 					/* don't break so fail path works correct */
655 					fail = 1;
656 
657 				if (connector->dpms != DRM_MODE_DPMS_ON) {
658 					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
659 					mode_changed = true;
660 				}
661 
662 				break;
663 			}
664 		}
665 
666 		if (new_encoder != connector->encoder) {
667 			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
668 			mode_changed = true;
669 			/* If the encoder is reused for another connector, then
670 			 * the appropriate crtc will be set later.
671 			 */
672 			if (connector->encoder)
673 				connector->encoder->crtc = NULL;
674 			connector->encoder = new_encoder;
675 		}
676 	}
677 	drm_connector_list_iter_end(&conn_iter);
678 
679 	if (fail) {
680 		ret = -EINVAL;
681 		goto fail;
682 	}
683 
684 	count = 0;
685 	drm_connector_list_iter_begin(dev, &conn_iter);
686 	drm_for_each_connector_iter(connector, &conn_iter) {
687 		if (!connector->encoder)
688 			continue;
689 
690 		if (connector->encoder->crtc == set->crtc)
691 			new_crtc = NULL;
692 		else
693 			new_crtc = connector->encoder->crtc;
694 
695 		for (ro = 0; ro < set->num_connectors; ro++) {
696 			if (set->connectors[ro] == connector)
697 				new_crtc = set->crtc;
698 		}
699 
700 		/* Make sure the new CRTC will work with the encoder */
701 		if (new_crtc &&
702 		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
703 			ret = -EINVAL;
704 			drm_connector_list_iter_end(&conn_iter);
705 			goto fail;
706 		}
707 		if (new_crtc != connector->encoder->crtc) {
708 			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
709 			mode_changed = true;
710 			connector->encoder->crtc = new_crtc;
711 		}
712 		if (new_crtc) {
713 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
714 				      connector->base.id, connector->name,
715 				      new_crtc->base.id, new_crtc->name);
716 		} else {
717 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
718 				      connector->base.id, connector->name);
719 		}
720 	}
721 	drm_connector_list_iter_end(&conn_iter);
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_connector_list_iter_begin(dev, &conn_iter);
777 	drm_for_each_connector_iter(connector, &conn_iter)
778 		connector->encoder = save_connector_encoders[count++];
779 	drm_connector_list_iter_end(&conn_iter);
780 
781 	/* after fail drop reference on all unbound connectors in set, let
782 	 * bound connectors keep their reference
783 	 */
784 	for (ro = 0; ro < set->num_connectors; ro++) {
785 		if (set->connectors[ro]->encoder)
786 			continue;
787 		drm_connector_put(set->connectors[ro]);
788 	}
789 
790 	/* Try to restore the config */
791 	if (mode_changed &&
792 	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
793 				      save_set.y, save_set.fb))
794 		DRM_ERROR("failed to restore config after modeset failure\n");
795 
796 	kfree(save_connector_encoders);
797 	kfree(save_encoder_crtcs);
798 	return ret;
799 }
800 EXPORT_SYMBOL(drm_crtc_helper_set_config);
801 
802 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
803 {
804 	int dpms = DRM_MODE_DPMS_OFF;
805 	struct drm_connector *connector;
806 	struct drm_connector_list_iter conn_iter;
807 	struct drm_device *dev = encoder->dev;
808 
809 	drm_connector_list_iter_begin(dev, &conn_iter);
810 	drm_for_each_connector_iter(connector, &conn_iter)
811 		if (connector->encoder == encoder)
812 			if (connector->dpms < dpms)
813 				dpms = connector->dpms;
814 	drm_connector_list_iter_end(&conn_iter);
815 
816 	return dpms;
817 }
818 
819 /* Helper which handles bridge ordering around encoder dpms */
820 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
821 {
822 	const struct drm_encoder_helper_funcs *encoder_funcs;
823 
824 	encoder_funcs = encoder->helper_private;
825 	if (!encoder_funcs)
826 		return;
827 
828 	if (encoder_funcs->dpms)
829 		encoder_funcs->dpms(encoder, mode);
830 }
831 
832 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
833 {
834 	int dpms = DRM_MODE_DPMS_OFF;
835 	struct drm_connector *connector;
836 	struct drm_connector_list_iter conn_iter;
837 	struct drm_device *dev = crtc->dev;
838 
839 	drm_connector_list_iter_begin(dev, &conn_iter);
840 	drm_for_each_connector_iter(connector, &conn_iter)
841 		if (connector->encoder && connector->encoder->crtc == crtc)
842 			if (connector->dpms < dpms)
843 				dpms = connector->dpms;
844 	drm_connector_list_iter_end(&conn_iter);
845 
846 	return dpms;
847 }
848 
849 /**
850  * drm_helper_connector_dpms() - connector dpms helper implementation
851  * @connector: affected connector
852  * @mode: DPMS mode
853  *
854  * The drm_helper_connector_dpms() helper function implements the
855  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
856  * helpers.
857  *
858  * This is the main helper function provided by the CRTC helper framework for
859  * implementing the DPMS connector attribute. It computes the new desired DPMS
860  * state for all encoders and CRTCs in the output mesh and calls the
861  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
862  * provided by the driver.
863  *
864  * This function is deprecated.  New drivers must implement atomic modeset
865  * support, where DPMS is handled in the DRM core.
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 	WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
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_resume_force_mode - force-restore mode setting configuration
917  * @dev: drm_device which should be restored
918  *
919  * Drivers which use the mode setting helpers can use this function to
920  * force-restore the mode setting configuration e.g. on resume or when something
921  * else might have trampled over the hw state (like some overzealous old BIOSen
922  * tended to do).
923  *
924  * This helper doesn't provide a error return value since restoring the old
925  * config should never fail due to resource allocation issues since the driver
926  * has successfully set the restored configuration already. Hence this should
927  * boil down to the equivalent of a few dpms on calls, which also don't provide
928  * an error code.
929  *
930  * Drivers where simply restoring an old configuration again might fail (e.g.
931  * due to slight differences in allocating shared resources when the
932  * configuration is restored in a different order than when userspace set it up)
933  * need to use their own restore logic.
934  *
935  * This function is deprecated. New drivers should implement atomic mode-
936  * setting and use the atomic suspend/resume helpers.
937  *
938  * See also:
939  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
940  */
941 void drm_helper_resume_force_mode(struct drm_device *dev)
942 {
943 	struct drm_crtc *crtc;
944 	struct drm_encoder *encoder;
945 	const struct drm_crtc_helper_funcs *crtc_funcs;
946 	int encoder_dpms;
947 	bool ret;
948 
949 	WARN_ON(drm_drv_uses_atomic_modeset(dev));
950 
951 	drm_modeset_lock_all(dev);
952 	drm_for_each_crtc(crtc, dev) {
953 
954 		if (!crtc->enabled)
955 			continue;
956 
957 		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
958 					       crtc->x, crtc->y, crtc->primary->fb);
959 
960 		/* Restoring the old config should never fail! */
961 		if (ret == false)
962 			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
963 
964 		/* Turn off outputs that were already powered off */
965 		if (drm_helper_choose_crtc_dpms(crtc)) {
966 			drm_for_each_encoder(encoder, dev) {
967 
968 				if(encoder->crtc != crtc)
969 					continue;
970 
971 				encoder_dpms = drm_helper_choose_encoder_dpms(
972 							encoder);
973 
974 				drm_helper_encoder_dpms(encoder, encoder_dpms);
975 			}
976 
977 			crtc_funcs = crtc->helper_private;
978 			if (crtc_funcs->dpms)
979 				(*crtc_funcs->dpms) (crtc,
980 						     drm_helper_choose_crtc_dpms(crtc));
981 		}
982 	}
983 
984 	/* disable the unused connectors while restoring the modesetting */
985 	__drm_helper_disable_unused_functions(dev);
986 	drm_modeset_unlock_all(dev);
987 }
988 EXPORT_SYMBOL(drm_helper_resume_force_mode);
989 
990 /**
991  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
992  * @dev: DRM device whose CRTCs to turn off
993  *
994  * Drivers may want to call this on unload to ensure that all displays are
995  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
996  *
997  * Note: This should only be used by non-atomic legacy drivers. For an atomic
998  * version look at drm_atomic_helper_shutdown().
999  *
1000  * Returns:
1001  * Zero on success, error code on failure.
1002  */
1003 int drm_helper_force_disable_all(struct drm_device *dev)
1004 {
1005 	struct drm_crtc *crtc;
1006 	int ret = 0;
1007 
1008 	drm_modeset_lock_all(dev);
1009 	drm_for_each_crtc(crtc, dev)
1010 		if (crtc->enabled) {
1011 			struct drm_mode_set set = {
1012 				.crtc = crtc,
1013 			};
1014 
1015 			ret = drm_mode_set_config_internal(&set);
1016 			if (ret)
1017 				goto out;
1018 		}
1019 out:
1020 	drm_modeset_unlock_all(dev);
1021 	return ret;
1022 }
1023 EXPORT_SYMBOL(drm_helper_force_disable_all);
1024