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#include <linux/dynamic_debug.h>
36
37#include <drm/drm_atomic.h>
38#include <drm/drm_atomic_helper.h>
39#include <drm/drm_atomic_uapi.h>
40#include <drm/drm_bridge.h>
41#include <drm/drm_crtc.h>
42#include <drm/drm_crtc_helper.h>
43#include <drm/drm_drv.h>
44#include <drm/drm_edid.h>
45#include <drm/drm_encoder.h>
46#include <drm/drm_fourcc.h>
47#include <drm/drm_framebuffer.h>
48#include <drm/drm_print.h>
49#include <drm/drm_vblank.h>
50
51#include "drm_crtc_helper_internal.h"
52
53DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
54			"DRM_UT_CORE",
55			"DRM_UT_DRIVER",
56			"DRM_UT_KMS",
57			"DRM_UT_PRIME",
58			"DRM_UT_ATOMIC",
59			"DRM_UT_VBL",
60			"DRM_UT_STATE",
61			"DRM_UT_LEASE",
62			"DRM_UT_DP",
63			"DRM_UT_DRMRES");
64
65/**
66 * DOC: overview
67 *
68 * The CRTC modeset helper library provides a default set_config implementation
69 * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
70 * the same callbacks which drivers can use to e.g. restore the modeset
71 * configuration on resume with drm_helper_resume_force_mode().
72 *
73 * Note that this helper library doesn't track the current power state of CRTCs
74 * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
75 * though the hardware is already in the desired state. This deficiency has been
76 * fixed in the atomic helpers.
77 *
78 * The driver callbacks are mostly compatible with the atomic modeset helpers,
79 * except for the handling of the primary plane: Atomic helpers require that the
80 * primary plane is implemented as a real standalone plane and not directly tied
81 * to the CRTC state. For easier transition this library provides functions to
82 * implement the old semantics required by the CRTC helpers using the new plane
83 * and atomic helper callbacks.
84 *
85 * Drivers are strongly urged to convert to the atomic helpers (by way of first
86 * converting to the plane helpers). New drivers must not use these functions
87 * but need to implement the atomic interface instead, potentially using the
88 * atomic helpers for that.
89 *
90 * These legacy modeset helpers use the same function table structures as
91 * all other modesetting helpers. See the documentation for struct
92 * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
93 * &drm_connector_helper_funcs.
94 */
95
96/**
97 * drm_helper_encoder_in_use - check if a given encoder is in use
98 * @encoder: encoder to check
99 *
100 * Checks whether @encoder is with the current mode setting output configuration
101 * in use by any connector. This doesn't mean that it is actually enabled since
102 * the DPMS state is tracked separately.
103 *
104 * Returns:
105 * True if @encoder is used, false otherwise.
106 */
107bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
108{
109	struct drm_connector *connector;
110	struct drm_connector_list_iter conn_iter;
111	struct drm_device *dev = encoder->dev;
112
113	WARN_ON(drm_drv_uses_atomic_modeset(dev));
114
115	/*
116	 * We can expect this mutex to be locked if we are not panicking.
117	 * Locking is currently fubar in the panic handler.
118	 */
119	if (!oops_in_progress) {
120		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
121		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
122	}
123
124
125	drm_connector_list_iter_begin(dev, &conn_iter);
126	drm_for_each_connector_iter(connector, &conn_iter) {
127		if (connector->encoder == encoder) {
128			drm_connector_list_iter_end(&conn_iter);
129			return true;
130		}
131	}
132	drm_connector_list_iter_end(&conn_iter);
133	return false;
134}
135EXPORT_SYMBOL(drm_helper_encoder_in_use);
136
137/**
138 * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
139 * @crtc: CRTC to check
140 *
141 * Checks whether @crtc is with the current mode setting output configuration
142 * in use by any connector. This doesn't mean that it is actually enabled since
143 * the DPMS state is tracked separately.
144 *
145 * Returns:
146 * True if @crtc is used, false otherwise.
147 */
148bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
149{
150	struct drm_encoder *encoder;
151	struct drm_device *dev = crtc->dev;
152
153	WARN_ON(drm_drv_uses_atomic_modeset(dev));
154
155	/*
156	 * We can expect this mutex to be locked if we are not panicking.
157	 * Locking is currently fubar in the panic handler.
158	 */
159	if (!oops_in_progress)
160		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
161
162	drm_for_each_encoder(encoder, dev)
163		if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
164			return true;
165	return false;
166}
167EXPORT_SYMBOL(drm_helper_crtc_in_use);
168
169static void
170drm_encoder_disable(struct drm_encoder *encoder)
171{
172	const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
173
174	if (!encoder_funcs)
175		return;
176
177	if (encoder_funcs->disable)
178		(*encoder_funcs->disable)(encoder);
179	else if (encoder_funcs->dpms)
180		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
181}
182
183static void __drm_helper_disable_unused_functions(struct drm_device *dev)
184{
185	struct drm_encoder *encoder;
186	struct drm_crtc *crtc;
187
188	drm_warn_on_modeset_not_all_locked(dev);
189
190	drm_for_each_encoder(encoder, dev) {
191		if (!drm_helper_encoder_in_use(encoder)) {
192			drm_encoder_disable(encoder);
193			/* disconnect encoder from any connector */
194			encoder->crtc = NULL;
195		}
196	}
197
198	drm_for_each_crtc(crtc, dev) {
199		const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
200
201		crtc->enabled = drm_helper_crtc_in_use(crtc);
202		if (!crtc->enabled) {
203			if (crtc_funcs->disable)
204				(*crtc_funcs->disable)(crtc);
205			else
206				(*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
207			crtc->primary->fb = NULL;
208		}
209	}
210}
211
212/**
213 * drm_helper_disable_unused_functions - disable unused objects
214 * @dev: DRM device
215 *
216 * This function walks through the entire mode setting configuration of @dev. It
217 * will remove any CRTC links of unused encoders and encoder links of
218 * disconnected connectors. Then it will disable all unused encoders and CRTCs
219 * either by calling their disable callback if available or by calling their
220 * dpms callback with DRM_MODE_DPMS_OFF.
221 *
222 * NOTE:
223 *
224 * This function is part of the legacy modeset helper library and will cause
225 * major confusion with atomic drivers. This is because atomic helpers guarantee
226 * to never call ->disable() hooks on a disabled function, or ->enable() hooks
227 * on an enabled functions. drm_helper_disable_unused_functions() on the other
228 * hand throws such guarantees into the wind and calls disable hooks
229 * unconditionally on unused functions.
230 */
231void drm_helper_disable_unused_functions(struct drm_device *dev)
232{
233	WARN_ON(drm_drv_uses_atomic_modeset(dev));
234
235	drm_modeset_lock_all(dev);
236	__drm_helper_disable_unused_functions(dev);
237	drm_modeset_unlock_all(dev);
238}
239EXPORT_SYMBOL(drm_helper_disable_unused_functions);
240
241/*
242 * Check the CRTC we're going to map each output to vs. its current
243 * CRTC.  If they don't match, we have to disable the output and the CRTC
244 * since the driver will have to re-route things.
245 */
246static void
247drm_crtc_prepare_encoders(struct drm_device *dev)
248{
249	const struct drm_encoder_helper_funcs *encoder_funcs;
250	struct drm_encoder *encoder;
251
252	drm_for_each_encoder(encoder, dev) {
253		encoder_funcs = encoder->helper_private;
254		if (!encoder_funcs)
255			continue;
256
257		/* Disable unused encoders */
258		if (encoder->crtc == NULL)
259			drm_encoder_disable(encoder);
260	}
261}
262
263/**
264 * drm_crtc_helper_set_mode - internal helper to set a mode
265 * @crtc: CRTC to program
266 * @mode: mode to use
267 * @x: horizontal offset into the surface
268 * @y: vertical offset into the surface
269 * @old_fb: old framebuffer, for cleanup
270 *
271 * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
272 * to fixup or reject the mode prior to trying to set it. This is an internal
273 * helper that drivers could e.g. use to update properties that require the
274 * entire output pipe to be disabled and re-enabled in a new configuration. For
275 * example for changing whether audio is enabled on a hdmi link or for changing
276 * panel fitter or dither attributes. It is also called by the
277 * drm_crtc_helper_set_config() helper function to drive the mode setting
278 * sequence.
279 *
280 * Returns:
281 * True if the mode was set successfully, false otherwise.
282 */
283bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
284			      struct drm_display_mode *mode,
285			      int x, int y,
286			      struct drm_framebuffer *old_fb)
287{
288	struct drm_device *dev = crtc->dev;
289	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
290	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
291	const struct drm_encoder_helper_funcs *encoder_funcs;
292	int saved_x, saved_y;
293	bool saved_enabled;
294	struct drm_encoder *encoder;
295	bool ret = true;
296
297	WARN_ON(drm_drv_uses_atomic_modeset(dev));
298
299	drm_warn_on_modeset_not_all_locked(dev);
300
301	saved_enabled = crtc->enabled;
302	crtc->enabled = drm_helper_crtc_in_use(crtc);
303	if (!crtc->enabled)
304		return true;
305
306	adjusted_mode = drm_mode_duplicate(dev, mode);
307	if (!adjusted_mode) {
308		crtc->enabled = saved_enabled;
309		return false;
310	}
311
312	drm_mode_init(&saved_mode, &crtc->mode);
313	drm_mode_init(&saved_hwmode, &crtc->hwmode);
314	saved_x = crtc->x;
315	saved_y = crtc->y;
316
317	/* Update crtc values up front so the driver can rely on them for mode
318	 * setting.
319	 */
320	drm_mode_copy(&crtc->mode, mode);
321	crtc->x = x;
322	crtc->y = y;
323
324	/* Pass our mode to the connectors and the CRTC to give them a chance to
325	 * adjust it according to limitations or connector properties, and also
326	 * a chance to reject the mode entirely.
327	 */
328	drm_for_each_encoder(encoder, dev) {
329
330		if (encoder->crtc != crtc)
331			continue;
332
333		encoder_funcs = encoder->helper_private;
334		if (!encoder_funcs)
335			continue;
336
337		encoder_funcs = encoder->helper_private;
338		if (encoder_funcs->mode_fixup) {
339			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
340							      adjusted_mode))) {
341				DRM_DEBUG_KMS("Encoder fixup failed\n");
342				goto done;
343			}
344		}
345	}
346
347	if (crtc_funcs->mode_fixup) {
348		if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
349						adjusted_mode))) {
350			DRM_DEBUG_KMS("CRTC fixup failed\n");
351			goto done;
352		}
353	}
354	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
355
356	drm_mode_copy(&crtc->hwmode, adjusted_mode);
357
358	/* Prepare the encoders and CRTCs before setting the mode. */
359	drm_for_each_encoder(encoder, dev) {
360
361		if (encoder->crtc != crtc)
362			continue;
363
364		encoder_funcs = encoder->helper_private;
365		if (!encoder_funcs)
366			continue;
367
368		/* Disable the encoders as the first thing we do. */
369		if (encoder_funcs->prepare)
370			encoder_funcs->prepare(encoder);
371	}
372
373	drm_crtc_prepare_encoders(dev);
374
375	crtc_funcs->prepare(crtc);
376
377	/* Set up the DPLL and any encoders state that needs to adjust or depend
378	 * on the DPLL.
379	 */
380	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
381	if (!ret)
382	    goto done;
383
384	drm_for_each_encoder(encoder, dev) {
385
386		if (encoder->crtc != crtc)
387			continue;
388
389		encoder_funcs = encoder->helper_private;
390		if (!encoder_funcs)
391			continue;
392
393		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
394			encoder->base.id, encoder->name, mode->name);
395		if (encoder_funcs->mode_set)
396			encoder_funcs->mode_set(encoder, mode, adjusted_mode);
397	}
398
399	/* Now enable the clocks, plane, pipe, and connectors that we set up. */
400	crtc_funcs->commit(crtc);
401
402	drm_for_each_encoder(encoder, dev) {
403
404		if (encoder->crtc != crtc)
405			continue;
406
407		encoder_funcs = encoder->helper_private;
408		if (!encoder_funcs)
409			continue;
410
411		if (encoder_funcs->commit)
412			encoder_funcs->commit(encoder);
413	}
414
415	/* Calculate and store various constants which
416	 * are later needed by vblank and swap-completion
417	 * timestamping. They are derived from true hwmode.
418	 */
419	drm_calc_timestamping_constants(crtc, &crtc->hwmode);
420
421	/* FIXME: add subpixel order */
422done:
423	drm_mode_destroy(dev, adjusted_mode);
424	if (!ret) {
425		crtc->enabled = saved_enabled;
426		drm_mode_copy(&crtc->mode, &saved_mode);
427		drm_mode_copy(&crtc->hwmode, &saved_hwmode);
428		crtc->x = saved_x;
429		crtc->y = saved_y;
430	}
431
432	return ret;
433}
434EXPORT_SYMBOL(drm_crtc_helper_set_mode);
435
436/**
437 * drm_crtc_helper_atomic_check() - Helper to check CRTC atomic-state
438 * @crtc: CRTC to check
439 * @state: atomic state object
440 *
441 * Provides a default CRTC-state check handler for CRTCs that only have
442 * one primary plane attached to it. This is often the case for the CRTC
443 * of simple framebuffers.
444 *
445 * RETURNS:
446 * Zero on success, or an errno code otherwise.
447 */
448int drm_crtc_helper_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
449{
450	struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
451
452	if (!new_crtc_state->enable)
453		return 0;
454
455	return drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
456}
457EXPORT_SYMBOL(drm_crtc_helper_atomic_check);
458
459static void
460drm_crtc_helper_disable(struct drm_crtc *crtc)
461{
462	struct drm_device *dev = crtc->dev;
463	struct drm_connector *connector;
464	struct drm_encoder *encoder;
465
466	/* Decouple all encoders and their attached connectors from this crtc */
467	drm_for_each_encoder(encoder, dev) {
468		struct drm_connector_list_iter conn_iter;
469
470		if (encoder->crtc != crtc)
471			continue;
472
473		drm_connector_list_iter_begin(dev, &conn_iter);
474		drm_for_each_connector_iter(connector, &conn_iter) {
475			if (connector->encoder != encoder)
476				continue;
477
478			connector->encoder = NULL;
479
480			/*
481			 * drm_helper_disable_unused_functions() ought to be
482			 * doing this, but since we've decoupled the encoder
483			 * from the connector above, the required connection
484			 * between them is henceforth no longer available.
485			 */
486			connector->dpms = DRM_MODE_DPMS_OFF;
487
488			/* we keep a reference while the encoder is bound */
489			drm_connector_put(connector);
490		}
491		drm_connector_list_iter_end(&conn_iter);
492	}
493
494	__drm_helper_disable_unused_functions(dev);
495}
496
497/*
498 * For connectors that support multiple encoders, either the
499 * .atomic_best_encoder() or .best_encoder() operation must be implemented.
500 */
501struct drm_encoder *
502drm_connector_get_single_encoder(struct drm_connector *connector)
503{
504	struct drm_encoder *encoder;
505
506	WARN_ON(hweight32(connector->possible_encoders) > 1);
507	drm_connector_for_each_possible_encoder(connector, encoder)
508		return encoder;
509
510	return NULL;
511}
512
513/**
514 * drm_crtc_helper_set_config - set a new config from userspace
515 * @set: mode set configuration
516 * @ctx: lock acquire context, not used here
517 *
518 * The drm_crtc_helper_set_config() helper function implements the of
519 * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
520 * helpers.
521 *
522 * It first tries to locate the best encoder for each connector by calling the
523 * connector @drm_connector_helper_funcs.best_encoder helper operation.
524 *
525 * After locating the appropriate encoders, the helper function will call the
526 * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
527 * or reject it completely in which case an error will be returned to the
528 * application. If the new configuration after mode adjustment is identical to
529 * the current configuration the helper function will return without performing
530 * any other operation.
531 *
532 * If the adjusted mode is identical to the current mode but changes to the
533 * frame buffer need to be applied, the drm_crtc_helper_set_config() function
534 * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
535 *
536 * If the adjusted mode differs from the current mode, or if the
537 * ->mode_set_base() helper operation is not provided, the helper function
538 * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
539 * and ->commit() CRTC and encoder helper operations, in that order.
540 * Alternatively it can also use the dpms and disable helper operations. For
541 * details see &struct drm_crtc_helper_funcs and struct
542 * &drm_encoder_helper_funcs.
543 *
544 * This function is deprecated.  New drivers must implement atomic modeset
545 * support, for which this function is unsuitable. Instead drivers should use
546 * drm_atomic_helper_set_config().
547 *
548 * Returns:
549 * Returns 0 on success, negative errno numbers on failure.
550 */
551int drm_crtc_helper_set_config(struct drm_mode_set *set,
552			       struct drm_modeset_acquire_ctx *ctx)
553{
554	struct drm_device *dev;
555	struct drm_crtc **save_encoder_crtcs, *new_crtc;
556	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
557	bool mode_changed = false; /* if true do a full mode set */
558	bool fb_changed = false; /* if true and !mode_changed just do a flip */
559	struct drm_connector *connector;
560	struct drm_connector_list_iter conn_iter;
561	int count = 0, ro, fail = 0;
562	const struct drm_crtc_helper_funcs *crtc_funcs;
563	struct drm_mode_set save_set;
564	int ret;
565	int i;
566
567	DRM_DEBUG_KMS("\n");
568
569	BUG_ON(!set);
570	BUG_ON(!set->crtc);
571	BUG_ON(!set->crtc->helper_private);
572
573	/* Enforce sane interface api - has been abused by the fb helper. */
574	BUG_ON(!set->mode && set->fb);
575	BUG_ON(set->fb && set->num_connectors == 0);
576
577	crtc_funcs = set->crtc->helper_private;
578
579	dev = set->crtc->dev;
580	WARN_ON(drm_drv_uses_atomic_modeset(dev));
581
582	if (!set->mode)
583		set->fb = NULL;
584
585	if (set->fb) {
586		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
587			      set->crtc->base.id, set->crtc->name,
588			      set->fb->base.id,
589			      (int)set->num_connectors, set->x, set->y);
590	} else {
591		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
592			      set->crtc->base.id, set->crtc->name);
593		drm_crtc_helper_disable(set->crtc);
594		return 0;
595	}
596
597	drm_warn_on_modeset_not_all_locked(dev);
598
599	/*
600	 * Allocate space for the backup of all (non-pointer) encoder and
601	 * connector data.
602	 */
603	save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
604				sizeof(struct drm_crtc *), GFP_KERNEL);
605	if (!save_encoder_crtcs)
606		return -ENOMEM;
607
608	save_connector_encoders = kcalloc(dev->mode_config.num_connector,
609				sizeof(struct drm_encoder *), GFP_KERNEL);
610	if (!save_connector_encoders) {
611		kfree(save_encoder_crtcs);
612		return -ENOMEM;
613	}
614
615	/*
616	 * Copy data. Note that driver private data is not affected.
617	 * Should anything bad happen only the expected state is
618	 * restored, not the drivers personal bookkeeping.
619	 */
620	count = 0;
621	drm_for_each_encoder(encoder, dev) {
622		save_encoder_crtcs[count++] = encoder->crtc;
623	}
624
625	count = 0;
626	drm_connector_list_iter_begin(dev, &conn_iter);
627	drm_for_each_connector_iter(connector, &conn_iter)
628		save_connector_encoders[count++] = connector->encoder;
629	drm_connector_list_iter_end(&conn_iter);
630
631	save_set.crtc = set->crtc;
632	save_set.mode = &set->crtc->mode;
633	save_set.x = set->crtc->x;
634	save_set.y = set->crtc->y;
635	save_set.fb = set->crtc->primary->fb;
636
637	/* We should be able to check here if the fb has the same properties
638	 * and then just flip_or_move it */
639	if (set->crtc->primary->fb != set->fb) {
640		/* If we have no fb then treat it as a full mode set */
641		if (set->crtc->primary->fb == NULL) {
642			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
643			mode_changed = true;
644		} else if (set->fb->format != set->crtc->primary->fb->format) {
645			mode_changed = true;
646		} else
647			fb_changed = true;
648	}
649
650	if (set->x != set->crtc->x || set->y != set->crtc->y)
651		fb_changed = true;
652
653	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
654		DRM_DEBUG_KMS("modes are different, full mode set\n");
655		drm_mode_debug_printmodeline(&set->crtc->mode);
656		drm_mode_debug_printmodeline(set->mode);
657		mode_changed = true;
658	}
659
660	/* take a reference on all unbound connectors in set, reuse the
661	 * already taken reference for bound connectors
662	 */
663	for (ro = 0; ro < set->num_connectors; ro++) {
664		if (set->connectors[ro]->encoder)
665			continue;
666		drm_connector_get(set->connectors[ro]);
667	}
668
669	/* a) traverse passed in connector list and get encoders for them */
670	count = 0;
671	drm_connector_list_iter_begin(dev, &conn_iter);
672	drm_for_each_connector_iter(connector, &conn_iter) {
673		const struct drm_connector_helper_funcs *connector_funcs =
674			connector->helper_private;
675		new_encoder = connector->encoder;
676		for (ro = 0; ro < set->num_connectors; ro++) {
677			if (set->connectors[ro] == connector) {
678				if (connector_funcs->best_encoder)
679					new_encoder = connector_funcs->best_encoder(connector);
680				else
681					new_encoder = drm_connector_get_single_encoder(connector);
682
683				/* if we can't get an encoder for a connector
684				   we are setting now - then fail */
685				if (new_encoder == NULL)
686					/* don't break so fail path works correct */
687					fail = 1;
688
689				if (connector->dpms != DRM_MODE_DPMS_ON) {
690					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
691					mode_changed = true;
692				}
693
694				break;
695			}
696		}
697
698		if (new_encoder != connector->encoder) {
699			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
700			mode_changed = true;
701			/* If the encoder is reused for another connector, then
702			 * the appropriate crtc will be set later.
703			 */
704			if (connector->encoder)
705				connector->encoder->crtc = NULL;
706			connector->encoder = new_encoder;
707		}
708	}
709	drm_connector_list_iter_end(&conn_iter);
710
711	if (fail) {
712		ret = -EINVAL;
713		goto fail;
714	}
715
716	count = 0;
717	drm_connector_list_iter_begin(dev, &conn_iter);
718	drm_for_each_connector_iter(connector, &conn_iter) {
719		if (!connector->encoder)
720			continue;
721
722		if (connector->encoder->crtc == set->crtc)
723			new_crtc = NULL;
724		else
725			new_crtc = connector->encoder->crtc;
726
727		for (ro = 0; ro < set->num_connectors; ro++) {
728			if (set->connectors[ro] == connector)
729				new_crtc = set->crtc;
730		}
731
732		/* Make sure the new CRTC will work with the encoder */
733		if (new_crtc &&
734		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
735			ret = -EINVAL;
736			drm_connector_list_iter_end(&conn_iter);
737			goto fail;
738		}
739		if (new_crtc != connector->encoder->crtc) {
740			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
741			mode_changed = true;
742			connector->encoder->crtc = new_crtc;
743		}
744		if (new_crtc) {
745			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
746				      connector->base.id, connector->name,
747				      new_crtc->base.id, new_crtc->name);
748		} else {
749			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
750				      connector->base.id, connector->name);
751		}
752	}
753	drm_connector_list_iter_end(&conn_iter);
754
755	/* mode_set_base is not a required function */
756	if (fb_changed && !crtc_funcs->mode_set_base)
757		mode_changed = true;
758
759	if (mode_changed) {
760		if (drm_helper_crtc_in_use(set->crtc)) {
761			DRM_DEBUG_KMS("attempting to set mode from"
762					" userspace\n");
763			drm_mode_debug_printmodeline(set->mode);
764			set->crtc->primary->fb = set->fb;
765			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
766						      set->x, set->y,
767						      save_set.fb)) {
768				DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
769					  set->crtc->base.id, set->crtc->name);
770				set->crtc->primary->fb = save_set.fb;
771				ret = -EINVAL;
772				goto fail;
773			}
774			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
775			for (i = 0; i < set->num_connectors; i++) {
776				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
777					      set->connectors[i]->name);
778				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
779			}
780		}
781		__drm_helper_disable_unused_functions(dev);
782	} else if (fb_changed) {
783		set->crtc->x = set->x;
784		set->crtc->y = set->y;
785		set->crtc->primary->fb = set->fb;
786		ret = crtc_funcs->mode_set_base(set->crtc,
787						set->x, set->y, save_set.fb);
788		if (ret != 0) {
789			set->crtc->x = save_set.x;
790			set->crtc->y = save_set.y;
791			set->crtc->primary->fb = save_set.fb;
792			goto fail;
793		}
794	}
795
796	kfree(save_connector_encoders);
797	kfree(save_encoder_crtcs);
798	return 0;
799
800fail:
801	/* Restore all previous data. */
802	count = 0;
803	drm_for_each_encoder(encoder, dev) {
804		encoder->crtc = save_encoder_crtcs[count++];
805	}
806
807	count = 0;
808	drm_connector_list_iter_begin(dev, &conn_iter);
809	drm_for_each_connector_iter(connector, &conn_iter)
810		connector->encoder = save_connector_encoders[count++];
811	drm_connector_list_iter_end(&conn_iter);
812
813	/* after fail drop reference on all unbound connectors in set, let
814	 * bound connectors keep their reference
815	 */
816	for (ro = 0; ro < set->num_connectors; ro++) {
817		if (set->connectors[ro]->encoder)
818			continue;
819		drm_connector_put(set->connectors[ro]);
820	}
821
822	/* Try to restore the config */
823	if (mode_changed &&
824	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
825				      save_set.y, save_set.fb))
826		DRM_ERROR("failed to restore config after modeset failure\n");
827
828	kfree(save_connector_encoders);
829	kfree(save_encoder_crtcs);
830	return ret;
831}
832EXPORT_SYMBOL(drm_crtc_helper_set_config);
833
834static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
835{
836	int dpms = DRM_MODE_DPMS_OFF;
837	struct drm_connector *connector;
838	struct drm_connector_list_iter conn_iter;
839	struct drm_device *dev = encoder->dev;
840
841	drm_connector_list_iter_begin(dev, &conn_iter);
842	drm_for_each_connector_iter(connector, &conn_iter)
843		if (connector->encoder == encoder)
844			if (connector->dpms < dpms)
845				dpms = connector->dpms;
846	drm_connector_list_iter_end(&conn_iter);
847
848	return dpms;
849}
850
851/* Helper which handles bridge ordering around encoder dpms */
852static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
853{
854	const struct drm_encoder_helper_funcs *encoder_funcs;
855
856	encoder_funcs = encoder->helper_private;
857	if (!encoder_funcs)
858		return;
859
860	if (encoder_funcs->dpms)
861		encoder_funcs->dpms(encoder, mode);
862}
863
864static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
865{
866	int dpms = DRM_MODE_DPMS_OFF;
867	struct drm_connector *connector;
868	struct drm_connector_list_iter conn_iter;
869	struct drm_device *dev = crtc->dev;
870
871	drm_connector_list_iter_begin(dev, &conn_iter);
872	drm_for_each_connector_iter(connector, &conn_iter)
873		if (connector->encoder && connector->encoder->crtc == crtc)
874			if (connector->dpms < dpms)
875				dpms = connector->dpms;
876	drm_connector_list_iter_end(&conn_iter);
877
878	return dpms;
879}
880
881/**
882 * drm_helper_connector_dpms() - connector dpms helper implementation
883 * @connector: affected connector
884 * @mode: DPMS mode
885 *
886 * The drm_helper_connector_dpms() helper function implements the
887 * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
888 * helpers.
889 *
890 * This is the main helper function provided by the CRTC helper framework for
891 * implementing the DPMS connector attribute. It computes the new desired DPMS
892 * state for all encoders and CRTCs in the output mesh and calls the
893 * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
894 * provided by the driver.
895 *
896 * This function is deprecated.  New drivers must implement atomic modeset
897 * support, where DPMS is handled in the DRM core.
898 *
899 * Returns:
900 * Always returns 0.
901 */
902int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
903{
904	struct drm_encoder *encoder = connector->encoder;
905	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
906	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
907
908	WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
909
910	if (mode == connector->dpms)
911		return 0;
912
913	old_dpms = connector->dpms;
914	connector->dpms = mode;
915
916	if (encoder)
917		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
918
919	/* from off to on, do crtc then encoder */
920	if (mode < old_dpms) {
921		if (crtc) {
922			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
923
924			if (crtc_funcs->dpms)
925				(*crtc_funcs->dpms) (crtc,
926						     drm_helper_choose_crtc_dpms(crtc));
927		}
928		if (encoder)
929			drm_helper_encoder_dpms(encoder, encoder_dpms);
930	}
931
932	/* from on to off, do encoder then crtc */
933	if (mode > old_dpms) {
934		if (encoder)
935			drm_helper_encoder_dpms(encoder, encoder_dpms);
936		if (crtc) {
937			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
938
939			if (crtc_funcs->dpms)
940				(*crtc_funcs->dpms) (crtc,
941						     drm_helper_choose_crtc_dpms(crtc));
942		}
943	}
944
945	return 0;
946}
947EXPORT_SYMBOL(drm_helper_connector_dpms);
948
949/**
950 * drm_helper_resume_force_mode - force-restore mode setting configuration
951 * @dev: drm_device which should be restored
952 *
953 * Drivers which use the mode setting helpers can use this function to
954 * force-restore the mode setting configuration e.g. on resume or when something
955 * else might have trampled over the hw state (like some overzealous old BIOSen
956 * tended to do).
957 *
958 * This helper doesn't provide a error return value since restoring the old
959 * config should never fail due to resource allocation issues since the driver
960 * has successfully set the restored configuration already. Hence this should
961 * boil down to the equivalent of a few dpms on calls, which also don't provide
962 * an error code.
963 *
964 * Drivers where simply restoring an old configuration again might fail (e.g.
965 * due to slight differences in allocating shared resources when the
966 * configuration is restored in a different order than when userspace set it up)
967 * need to use their own restore logic.
968 *
969 * This function is deprecated. New drivers should implement atomic mode-
970 * setting and use the atomic suspend/resume helpers.
971 *
972 * See also:
973 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
974 */
975void drm_helper_resume_force_mode(struct drm_device *dev)
976{
977	struct drm_crtc *crtc;
978	struct drm_encoder *encoder;
979	const struct drm_crtc_helper_funcs *crtc_funcs;
980	int encoder_dpms;
981	bool ret;
982
983	WARN_ON(drm_drv_uses_atomic_modeset(dev));
984
985	drm_modeset_lock_all(dev);
986	drm_for_each_crtc(crtc, dev) {
987
988		if (!crtc->enabled)
989			continue;
990
991		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
992					       crtc->x, crtc->y, crtc->primary->fb);
993
994		/* Restoring the old config should never fail! */
995		if (ret == false)
996			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
997
998		/* Turn off outputs that were already powered off */
999		if (drm_helper_choose_crtc_dpms(crtc)) {
1000			drm_for_each_encoder(encoder, dev) {
1001
1002				if(encoder->crtc != crtc)
1003					continue;
1004
1005				encoder_dpms = drm_helper_choose_encoder_dpms(
1006							encoder);
1007
1008				drm_helper_encoder_dpms(encoder, encoder_dpms);
1009			}
1010
1011			crtc_funcs = crtc->helper_private;
1012			if (crtc_funcs->dpms)
1013				(*crtc_funcs->dpms) (crtc,
1014						     drm_helper_choose_crtc_dpms(crtc));
1015		}
1016	}
1017
1018	/* disable the unused connectors while restoring the modesetting */
1019	__drm_helper_disable_unused_functions(dev);
1020	drm_modeset_unlock_all(dev);
1021}
1022EXPORT_SYMBOL(drm_helper_resume_force_mode);
1023
1024/**
1025 * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
1026 * @dev: DRM device whose CRTCs to turn off
1027 *
1028 * Drivers may want to call this on unload to ensure that all displays are
1029 * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
1030 *
1031 * Note: This should only be used by non-atomic legacy drivers. For an atomic
1032 * version look at drm_atomic_helper_shutdown().
1033 *
1034 * Returns:
1035 * Zero on success, error code on failure.
1036 */
1037int drm_helper_force_disable_all(struct drm_device *dev)
1038{
1039	struct drm_crtc *crtc;
1040	int ret = 0;
1041
1042	drm_modeset_lock_all(dev);
1043	drm_for_each_crtc(crtc, dev)
1044		if (crtc->enabled) {
1045			struct drm_mode_set set = {
1046				.crtc = crtc,
1047			};
1048
1049			ret = drm_mode_set_config_internal(&set);
1050			if (ret)
1051				goto out;
1052		}
1053out:
1054	drm_modeset_unlock_all(dev);
1055	return ret;
1056}
1057EXPORT_SYMBOL(drm_helper_force_disable_all);
1058