1/*	$NetBSD: drm_crtc_helper.c,v 1.7 2021/12/18 23:44:57 riastradh Exp $	*/
2
3/*
4 * Copyright (c) 2006-2008 Intel Corporation
5 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
6 *
7 * DRM core CRTC related functions
8 *
9 * Permission to use, copy, modify, distribute, and sell this software and its
10 * documentation for any purpose is hereby granted without fee, provided that
11 * the above copyright notice appear in all copies and that both that copyright
12 * notice and this permission notice appear in supporting documentation, and
13 * that the name of the copyright holders not be used in advertising or
14 * publicity pertaining to distribution of the software without specific,
15 * written prior permission.  The copyright holders make no representations
16 * about the suitability of this software for any purpose.  It is provided "as
17 * is" without express or implied warranty.
18 *
19 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
20 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
21 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
22 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
23 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
24 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
25 * OF THIS SOFTWARE.
26 *
27 * Authors:
28 *      Keith Packard
29 *	Eric Anholt <eric@anholt.net>
30 *      Dave Airlie <airlied@linux.ie>
31 *      Jesse Barnes <jesse.barnes@intel.com>
32 */
33
34#include <sys/cdefs.h>
35__KERNEL_RCSID(0, "$NetBSD: drm_crtc_helper.c,v 1.7 2021/12/18 23:44:57 riastradh Exp $");
36
37#include <linux/export.h>
38#include <linux/kernel.h>
39#include <linux/moduleparam.h>
40
41#include <drm/drm_atomic.h>
42#include <drm/drm_atomic_helper.h>
43#include <drm/drm_atomic_uapi.h>
44#include <drm/drm_bridge.h>
45#include <drm/drm_crtc.h>
46#include <drm/drm_crtc_helper.h>
47#include <drm/drm_drv.h>
48#include <drm/drm_edid.h>
49#include <drm/drm_encoder.h>
50#ifndef __NetBSD__
51#include <drm/drm_fb_helper.h>
52#endif
53#include <drm/drm_fourcc.h>
54#include <drm/drm_plane_helper.h>
55#include <drm/drm_print.h>
56#include <drm/drm_vblank.h>
57
58#include "drm_crtc_helper_internal.h"
59
60/**
61 * DOC: overview
62 *
63 * The CRTC modeset helper library provides a default set_config implementation
64 * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
65 * the same callbacks which drivers can use to e.g. restore the modeset
66 * configuration on resume with drm_helper_resume_force_mode().
67 *
68 * Note that this helper library doesn't track the current power state of CRTCs
69 * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
70 * though the hardware is already in the desired state. This deficiency has been
71 * fixed in the atomic helpers.
72 *
73 * The driver callbacks are mostly compatible with the atomic modeset helpers,
74 * except for the handling of the primary plane: Atomic helpers require that the
75 * primary plane is implemented as a real standalone plane and not directly tied
76 * to the CRTC state. For easier transition this library provides functions to
77 * implement the old semantics required by the CRTC helpers using the new plane
78 * and atomic helper callbacks.
79 *
80 * Drivers are strongly urged to convert to the atomic helpers (by way of first
81 * converting to the plane helpers). New drivers must not use these functions
82 * but need to implement the atomic interface instead, potentially using the
83 * atomic helpers for that.
84 *
85 * These legacy modeset helpers use the same function table structures as
86 * all other modesetting helpers. See the documentation for struct
87 * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
88 * &drm_connector_helper_funcs.
89 */
90
91/**
92 * drm_helper_encoder_in_use - check if a given encoder is in use
93 * @encoder: encoder to check
94 *
95 * Checks whether @encoder is with the current mode setting output configuration
96 * in use by any connector. This doesn't mean that it is actually enabled since
97 * the DPMS state is tracked separately.
98 *
99 * Returns:
100 * True if @encoder is used, false otherwise.
101 */
102bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
103{
104	struct drm_connector *connector;
105	struct drm_connector_list_iter conn_iter;
106	struct drm_device *dev = encoder->dev;
107
108	WARN_ON(drm_drv_uses_atomic_modeset(dev));
109
110	/*
111	 * We can expect this mutex to be locked if we are not panicking.
112	 * Locking is currently fubar in the panic handler.
113	 */
114	if (!oops_in_progress) {
115		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
116		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
117	}
118
119
120	drm_connector_list_iter_begin(dev, &conn_iter);
121	drm_for_each_connector_iter(connector, &conn_iter) {
122		if (connector->encoder == encoder) {
123			drm_connector_list_iter_end(&conn_iter);
124			return true;
125		}
126	}
127	drm_connector_list_iter_end(&conn_iter);
128	return false;
129}
130EXPORT_SYMBOL(drm_helper_encoder_in_use);
131
132/**
133 * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
134 * @crtc: CRTC to check
135 *
136 * Checks whether @crtc is with the current mode setting output configuration
137 * in use by any connector. This doesn't mean that it is actually enabled since
138 * the DPMS state is tracked separately.
139 *
140 * Returns:
141 * True if @crtc is used, false otherwise.
142 */
143bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
144{
145	struct drm_encoder *encoder;
146	struct drm_device *dev = crtc->dev;
147
148	WARN_ON(drm_drv_uses_atomic_modeset(dev));
149
150	/*
151	 * We can expect this mutex to be locked if we are not panicking.
152	 * Locking is currently fubar in the panic handler.
153	 */
154	if (!oops_in_progress)
155		WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
156
157	drm_for_each_encoder(encoder, dev)
158		if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
159			return true;
160	return false;
161}
162EXPORT_SYMBOL(drm_helper_crtc_in_use);
163
164static void
165drm_encoder_disable(struct drm_encoder *encoder)
166{
167	const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
168
169	if (!encoder_funcs)
170		return;
171
172	if (encoder_funcs->disable)
173		(*encoder_funcs->disable)(encoder);
174	else if (encoder_funcs->dpms)
175		(*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
176}
177
178static void __drm_helper_disable_unused_functions(struct drm_device *dev)
179{
180	struct drm_encoder *encoder;
181	struct drm_crtc *crtc;
182
183	drm_warn_on_modeset_not_all_locked(dev);
184
185	drm_for_each_encoder(encoder, dev) {
186		if (!drm_helper_encoder_in_use(encoder)) {
187			drm_encoder_disable(encoder);
188			/* disconnect encoder from any connector */
189			encoder->crtc = NULL;
190		}
191	}
192
193	drm_for_each_crtc(crtc, dev) {
194		const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
195		crtc->enabled = drm_helper_crtc_in_use(crtc);
196		if (!crtc->enabled) {
197			if (crtc_funcs->disable)
198				(*crtc_funcs->disable)(crtc);
199			else
200				(*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
201			crtc->primary->fb = NULL;
202		}
203	}
204}
205
206/**
207 * drm_helper_disable_unused_functions - disable unused objects
208 * @dev: DRM device
209 *
210 * This function walks through the entire mode setting configuration of @dev. It
211 * will remove any CRTC links of unused encoders and encoder links of
212 * disconnected connectors. Then it will disable all unused encoders and CRTCs
213 * either by calling their disable callback if available or by calling their
214 * dpms callback with DRM_MODE_DPMS_OFF.
215 *
216 * NOTE:
217 *
218 * This function is part of the legacy modeset helper library and will cause
219 * major confusion with atomic drivers. This is because atomic helpers guarantee
220 * to never call ->disable() hooks on a disabled function, or ->enable() hooks
221 * on an enabled functions. drm_helper_disable_unused_functions() on the other
222 * hand throws such guarantees into the wind and calls disable hooks
223 * unconditionally on unused functions.
224 */
225void drm_helper_disable_unused_functions(struct drm_device *dev)
226{
227	WARN_ON(drm_drv_uses_atomic_modeset(dev));
228
229	drm_modeset_lock_all(dev);
230	__drm_helper_disable_unused_functions(dev);
231	drm_modeset_unlock_all(dev);
232}
233EXPORT_SYMBOL(drm_helper_disable_unused_functions);
234
235/*
236 * Check the CRTC we're going to map each output to vs. its current
237 * CRTC.  If they don't match, we have to disable the output and the CRTC
238 * since the driver will have to re-route things.
239 */
240static void
241drm_crtc_prepare_encoders(struct drm_device *dev)
242{
243	const struct drm_encoder_helper_funcs *encoder_funcs;
244	struct drm_encoder *encoder;
245
246	drm_for_each_encoder(encoder, dev) {
247		encoder_funcs = encoder->helper_private;
248		if (!encoder_funcs)
249			continue;
250
251		/* Disable unused encoders */
252		if (encoder->crtc == NULL)
253			drm_encoder_disable(encoder);
254		/* Disable encoders whose CRTC is about to change */
255		if (encoder_funcs->get_crtc &&
256		    encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
257			drm_encoder_disable(encoder);
258	}
259}
260
261/**
262 * drm_crtc_helper_set_mode - internal helper to set a mode
263 * @crtc: CRTC to program
264 * @mode: mode to use
265 * @x: horizontal offset into the surface
266 * @y: vertical offset into the surface
267 * @old_fb: old framebuffer, for cleanup
268 *
269 * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
270 * to fixup or reject the mode prior to trying to set it. This is an internal
271 * helper that drivers could e.g. use to update properties that require the
272 * entire output pipe to be disabled and re-enabled in a new configuration. For
273 * example for changing whether audio is enabled on a hdmi link or for changing
274 * panel fitter or dither attributes. It is also called by the
275 * drm_crtc_helper_set_config() helper function to drive the mode setting
276 * sequence.
277 *
278 * Returns:
279 * True if the mode was set successfully, false otherwise.
280 */
281bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
282			      struct drm_display_mode *mode,
283			      int x, int y,
284			      struct drm_framebuffer *old_fb)
285{
286	struct drm_device *dev = crtc->dev;
287	struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
288	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
289	const struct drm_encoder_helper_funcs *encoder_funcs;
290	int saved_x, saved_y;
291	bool saved_enabled;
292	struct drm_encoder *encoder;
293	bool ret = true;
294
295	WARN_ON(drm_drv_uses_atomic_modeset(dev));
296
297	drm_warn_on_modeset_not_all_locked(dev);
298
299	saved_enabled = crtc->enabled;
300	crtc->enabled = drm_helper_crtc_in_use(crtc);
301	if (!crtc->enabled)
302		return true;
303
304	adjusted_mode = drm_mode_duplicate(dev, mode);
305	if (!adjusted_mode) {
306		crtc->enabled = saved_enabled;
307		return false;
308	}
309
310	saved_mode = crtc->mode;
311	saved_hwmode = crtc->hwmode;
312	saved_x = crtc->x;
313	saved_y = crtc->y;
314
315	/* Update crtc values up front so the driver can rely on them for mode
316	 * setting.
317	 */
318	crtc->mode = *mode;
319	crtc->x = x;
320	crtc->y = y;
321
322	/* Pass our mode to the connectors and the CRTC to give them a chance to
323	 * adjust it according to limitations or connector properties, and also
324	 * a chance to reject the mode entirely.
325	 */
326	drm_for_each_encoder(encoder, dev) {
327
328		if (encoder->crtc != crtc)
329			continue;
330
331		encoder_funcs = encoder->helper_private;
332		if (!encoder_funcs)
333			continue;
334
335		encoder_funcs = encoder->helper_private;
336		if (encoder_funcs->mode_fixup) {
337			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
338							      adjusted_mode))) {
339				DRM_DEBUG_KMS("Encoder fixup failed\n");
340				goto done;
341			}
342		}
343	}
344
345	if (crtc_funcs->mode_fixup) {
346		if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
347						adjusted_mode))) {
348			DRM_DEBUG_KMS("CRTC fixup failed\n");
349			goto done;
350		}
351	}
352	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
353
354	crtc->hwmode = *adjusted_mode;
355
356	/* Prepare the encoders and CRTCs before setting the mode. */
357	drm_for_each_encoder(encoder, dev) {
358
359		if (encoder->crtc != crtc)
360			continue;
361
362		encoder_funcs = encoder->helper_private;
363		if (!encoder_funcs)
364			continue;
365
366		/* Disable the encoders as the first thing we do. */
367		if (encoder_funcs->prepare)
368			encoder_funcs->prepare(encoder);
369	}
370
371	drm_crtc_prepare_encoders(dev);
372
373	crtc_funcs->prepare(crtc);
374
375	/* Set up the DPLL and any encoders state that needs to adjust or depend
376	 * on the DPLL.
377	 */
378	ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
379	if (!ret)
380	    goto done;
381
382	drm_for_each_encoder(encoder, dev) {
383
384		if (encoder->crtc != crtc)
385			continue;
386
387		encoder_funcs = encoder->helper_private;
388		if (!encoder_funcs)
389			continue;
390
391		DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
392			encoder->base.id, encoder->name, mode->name);
393		if (encoder_funcs->mode_set)
394			encoder_funcs->mode_set(encoder, 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		if (encoder_funcs->commit)
410			encoder_funcs->commit(encoder);
411	}
412
413	/* Calculate and store various constants which
414	 * are later needed by vblank and swap-completion
415	 * timestamping. They are derived from true hwmode.
416	 */
417	drm_calc_timestamping_constants(crtc, &crtc->hwmode);
418
419	/* FIXME: add subpixel order */
420done:
421	drm_mode_destroy(dev, adjusted_mode);
422	if (!ret) {
423		crtc->enabled = saved_enabled;
424		crtc->mode = saved_mode;
425		crtc->hwmode = saved_hwmode;
426		crtc->x = saved_x;
427		crtc->y = saved_y;
428	}
429
430	return ret;
431}
432EXPORT_SYMBOL(drm_crtc_helper_set_mode);
433
434static void
435drm_crtc_helper_disable(struct drm_crtc *crtc)
436{
437	struct drm_device *dev = crtc->dev;
438	struct drm_connector *connector;
439	struct drm_encoder *encoder;
440
441	/* Decouple all encoders and their attached connectors from this crtc */
442	drm_for_each_encoder(encoder, dev) {
443		struct drm_connector_list_iter conn_iter;
444
445		if (encoder->crtc != crtc)
446			continue;
447
448		drm_connector_list_iter_begin(dev, &conn_iter);
449		drm_for_each_connector_iter(connector, &conn_iter) {
450			if (connector->encoder != encoder)
451				continue;
452
453			connector->encoder = NULL;
454
455			/*
456			 * drm_helper_disable_unused_functions() ought to be
457			 * doing this, but since we've decoupled the encoder
458			 * from the connector above, the required connection
459			 * between them is henceforth no longer available.
460			 */
461			connector->dpms = DRM_MODE_DPMS_OFF;
462
463			/* we keep a reference while the encoder is bound */
464			drm_connector_put(connector);
465		}
466		drm_connector_list_iter_end(&conn_iter);
467	}
468
469	__drm_helper_disable_unused_functions(dev);
470}
471
472/*
473 * For connectors that support multiple encoders, either the
474 * .atomic_best_encoder() or .best_encoder() operation must be implemented.
475 */
476struct drm_encoder *
477drm_connector_get_single_encoder(struct drm_connector *connector)
478{
479	struct drm_encoder *encoder;
480
481	WARN_ON(hweight32(connector->possible_encoders) > 1);
482	drm_connector_for_each_possible_encoder(connector, encoder)
483		return encoder;
484
485	return NULL;
486}
487
488/**
489 * drm_crtc_helper_set_config - set a new config from userspace
490 * @set: mode set configuration
491 * @ctx: lock acquire context, not used here
492 *
493 * The drm_crtc_helper_set_config() helper function implements the of
494 * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
495 * helpers.
496 *
497 * It first tries to locate the best encoder for each connector by calling the
498 * connector @drm_connector_helper_funcs.best_encoder helper operation.
499 *
500 * After locating the appropriate encoders, the helper function will call the
501 * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
502 * or reject it completely in which case an error will be returned to the
503 * application. If the new configuration after mode adjustment is identical to
504 * the current configuration the helper function will return without performing
505 * any other operation.
506 *
507 * If the adjusted mode is identical to the current mode but changes to the
508 * frame buffer need to be applied, the drm_crtc_helper_set_config() function
509 * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
510 *
511 * If the adjusted mode differs from the current mode, or if the
512 * ->mode_set_base() helper operation is not provided, the helper function
513 * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
514 * and ->commit() CRTC and encoder helper operations, in that order.
515 * Alternatively it can also use the dpms and disable helper operations. For
516 * details see &struct drm_crtc_helper_funcs and struct
517 * &drm_encoder_helper_funcs.
518 *
519 * This function is deprecated.  New drivers must implement atomic modeset
520 * support, for which this function is unsuitable. Instead drivers should use
521 * drm_atomic_helper_set_config().
522 *
523 * Returns:
524 * Returns 0 on success, negative errno numbers on failure.
525 */
526int drm_crtc_helper_set_config(struct drm_mode_set *set,
527			       struct drm_modeset_acquire_ctx *ctx)
528{
529	struct drm_device *dev;
530	struct drm_crtc **save_encoder_crtcs, *new_crtc;
531	struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
532	bool mode_changed = false; /* if true do a full mode set */
533	bool fb_changed = false; /* if true and !mode_changed just do a flip */
534	struct drm_connector *connector;
535	struct drm_connector_list_iter conn_iter;
536	int count = 0, ro, fail = 0;
537	const struct drm_crtc_helper_funcs *crtc_funcs;
538	struct drm_mode_set save_set;
539	int ret;
540	int i;
541
542	DRM_DEBUG_KMS("\n");
543
544	BUG_ON(!set);
545	BUG_ON(!set->crtc);
546	BUG_ON(!set->crtc->helper_private);
547
548	/* Enforce sane interface api - has been abused by the fb helper. */
549	BUG_ON(!set->mode && set->fb);
550	BUG_ON(set->fb && set->num_connectors == 0);
551
552	crtc_funcs = set->crtc->helper_private;
553
554	dev = set->crtc->dev;
555	WARN_ON(drm_drv_uses_atomic_modeset(dev));
556
557	if (!set->mode)
558		set->fb = NULL;
559
560	if (set->fb) {
561		DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
562			      set->crtc->base.id, set->crtc->name,
563			      set->fb->base.id,
564			      (int)set->num_connectors, set->x, set->y);
565	} else {
566		DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
567			      set->crtc->base.id, set->crtc->name);
568		drm_crtc_helper_disable(set->crtc);
569		return 0;
570	}
571
572	drm_warn_on_modeset_not_all_locked(dev);
573
574	/*
575	 * Allocate space for the backup of all (non-pointer) encoder and
576	 * connector data.
577	 */
578	save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
579				sizeof(struct drm_crtc *), GFP_KERNEL);
580	if (!save_encoder_crtcs)
581		return -ENOMEM;
582
583	save_connector_encoders = kcalloc(dev->mode_config.num_connector,
584				sizeof(struct drm_encoder *), GFP_KERNEL);
585	if (!save_connector_encoders) {
586		kfree(save_encoder_crtcs);
587		return -ENOMEM;
588	}
589
590	/*
591	 * Copy data. Note that driver private data is not affected.
592	 * Should anything bad happen only the expected state is
593	 * restored, not the drivers personal bookkeeping.
594	 */
595	count = 0;
596	drm_for_each_encoder(encoder, dev) {
597		save_encoder_crtcs[count++] = encoder->crtc;
598	}
599
600	count = 0;
601	drm_connector_list_iter_begin(dev, &conn_iter);
602	drm_for_each_connector_iter(connector, &conn_iter)
603		save_connector_encoders[count++] = connector->encoder;
604	drm_connector_list_iter_end(&conn_iter);
605
606	save_set.crtc = set->crtc;
607	save_set.mode = &set->crtc->mode;
608	save_set.x = set->crtc->x;
609	save_set.y = set->crtc->y;
610	save_set.fb = set->crtc->primary->fb;
611
612	/* We should be able to check here if the fb has the same properties
613	 * and then just flip_or_move it */
614	if (set->crtc->primary->fb != set->fb) {
615		/* If we have no fb then treat it as a full mode set */
616		if (set->crtc->primary->fb == NULL) {
617			DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
618			mode_changed = true;
619		} else if (set->fb->format != set->crtc->primary->fb->format) {
620			mode_changed = true;
621		} else
622			fb_changed = true;
623	}
624
625	if (set->x != set->crtc->x || set->y != set->crtc->y)
626		fb_changed = true;
627
628	if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
629		DRM_DEBUG_KMS("modes are different, full mode set\n");
630		drm_mode_debug_printmodeline(&set->crtc->mode);
631		drm_mode_debug_printmodeline(set->mode);
632		mode_changed = true;
633	}
634
635	/* take a reference on all unbound connectors in set, reuse the
636	 * already taken reference for bound connectors
637	 */
638	for (ro = 0; ro < set->num_connectors; ro++) {
639		if (set->connectors[ro]->encoder)
640			continue;
641		drm_connector_get(set->connectors[ro]);
642	}
643
644	/* a) traverse passed in connector list and get encoders for them */
645	count = 0;
646	drm_connector_list_iter_begin(dev, &conn_iter);
647	drm_for_each_connector_iter(connector, &conn_iter) {
648		const struct drm_connector_helper_funcs *connector_funcs =
649			connector->helper_private;
650		new_encoder = connector->encoder;
651		for (ro = 0; ro < set->num_connectors; ro++) {
652			if (set->connectors[ro] == connector) {
653				if (connector_funcs->best_encoder)
654					new_encoder = connector_funcs->best_encoder(connector);
655				else
656					new_encoder = drm_connector_get_single_encoder(connector);
657
658				/* if we can't get an encoder for a connector
659				   we are setting now - then fail */
660				if (new_encoder == NULL)
661					/* don't break so fail path works correct */
662					fail = 1;
663
664				if (connector->dpms != DRM_MODE_DPMS_ON) {
665					DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
666					mode_changed = true;
667				}
668
669				break;
670			}
671		}
672
673		if (new_encoder != connector->encoder) {
674			DRM_DEBUG_KMS("encoder changed, full mode switch\n");
675			mode_changed = true;
676			/* If the encoder is reused for another connector, then
677			 * the appropriate crtc will be set later.
678			 */
679			if (connector->encoder)
680				connector->encoder->crtc = NULL;
681			connector->encoder = new_encoder;
682		}
683	}
684	drm_connector_list_iter_end(&conn_iter);
685
686	if (fail) {
687		ret = -EINVAL;
688		goto fail;
689	}
690
691	count = 0;
692	drm_connector_list_iter_begin(dev, &conn_iter);
693	drm_for_each_connector_iter(connector, &conn_iter) {
694		if (!connector->encoder)
695			continue;
696
697		if (connector->encoder->crtc == set->crtc)
698			new_crtc = NULL;
699		else
700			new_crtc = connector->encoder->crtc;
701
702		for (ro = 0; ro < set->num_connectors; ro++) {
703			if (set->connectors[ro] == connector)
704				new_crtc = set->crtc;
705		}
706
707		/* Make sure the new CRTC will work with the encoder */
708		if (new_crtc &&
709		    !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
710			ret = -EINVAL;
711			drm_connector_list_iter_end(&conn_iter);
712			goto fail;
713		}
714		if (new_crtc != connector->encoder->crtc) {
715			DRM_DEBUG_KMS("crtc changed, full mode switch\n");
716			mode_changed = true;
717			connector->encoder->crtc = new_crtc;
718		}
719		if (new_crtc) {
720			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
721				      connector->base.id, connector->name,
722				      new_crtc->base.id, new_crtc->name);
723		} else {
724			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
725				      connector->base.id, connector->name);
726		}
727	}
728	drm_connector_list_iter_end(&conn_iter);
729
730	/* mode_set_base is not a required function */
731	if (fb_changed && !crtc_funcs->mode_set_base)
732		mode_changed = true;
733
734	if (mode_changed) {
735		if (drm_helper_crtc_in_use(set->crtc)) {
736			DRM_DEBUG_KMS("attempting to set mode from"
737					" userspace\n");
738			drm_mode_debug_printmodeline(set->mode);
739			set->crtc->primary->fb = set->fb;
740			if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
741						      set->x, set->y,
742						      save_set.fb)) {
743				DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
744					  set->crtc->base.id, set->crtc->name);
745				set->crtc->primary->fb = save_set.fb;
746				ret = -EINVAL;
747				goto fail;
748			}
749			DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
750			for (i = 0; i < set->num_connectors; i++) {
751				DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
752					      set->connectors[i]->name);
753				set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
754			}
755		}
756		__drm_helper_disable_unused_functions(dev);
757	} else if (fb_changed) {
758		set->crtc->x = set->x;
759		set->crtc->y = set->y;
760		set->crtc->primary->fb = set->fb;
761		ret = crtc_funcs->mode_set_base(set->crtc,
762						set->x, set->y, save_set.fb);
763		if (ret != 0) {
764			set->crtc->x = save_set.x;
765			set->crtc->y = save_set.y;
766			set->crtc->primary->fb = save_set.fb;
767			goto fail;
768		}
769	}
770
771	kfree(save_connector_encoders);
772	kfree(save_encoder_crtcs);
773	return 0;
774
775fail:
776	/* Restore all previous data. */
777	count = 0;
778	drm_for_each_encoder(encoder, dev) {
779		encoder->crtc = save_encoder_crtcs[count++];
780	}
781
782	count = 0;
783	drm_connector_list_iter_begin(dev, &conn_iter);
784	drm_for_each_connector_iter(connector, &conn_iter)
785		connector->encoder = save_connector_encoders[count++];
786	drm_connector_list_iter_end(&conn_iter);
787
788	/* after fail drop reference on all unbound connectors in set, let
789	 * bound connectors keep their reference
790	 */
791	for (ro = 0; ro < set->num_connectors; ro++) {
792		if (set->connectors[ro]->encoder)
793			continue;
794		drm_connector_put(set->connectors[ro]);
795	}
796
797	/* Try to restore the config */
798	if (mode_changed &&
799	    !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
800				      save_set.y, save_set.fb))
801		DRM_ERROR("failed to restore config after modeset failure\n");
802
803	kfree(save_connector_encoders);
804	kfree(save_encoder_crtcs);
805	return ret;
806}
807EXPORT_SYMBOL(drm_crtc_helper_set_config);
808
809static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
810{
811	int dpms = DRM_MODE_DPMS_OFF;
812	struct drm_connector *connector;
813	struct drm_connector_list_iter conn_iter;
814	struct drm_device *dev = encoder->dev;
815
816	drm_connector_list_iter_begin(dev, &conn_iter);
817	drm_for_each_connector_iter(connector, &conn_iter)
818		if (connector->encoder == encoder)
819			if (connector->dpms < dpms)
820				dpms = connector->dpms;
821	drm_connector_list_iter_end(&conn_iter);
822
823	return dpms;
824}
825
826/* Helper which handles bridge ordering around encoder dpms */
827static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
828{
829	const struct drm_encoder_helper_funcs *encoder_funcs;
830
831	encoder_funcs = encoder->helper_private;
832	if (!encoder_funcs)
833		return;
834
835	if (encoder_funcs->dpms)
836		encoder_funcs->dpms(encoder, mode);
837}
838
839static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
840{
841	int dpms = DRM_MODE_DPMS_OFF;
842	struct drm_connector *connector;
843	struct drm_connector_list_iter conn_iter;
844	struct drm_device *dev = crtc->dev;
845
846	drm_connector_list_iter_begin(dev, &conn_iter);
847	drm_for_each_connector_iter(connector, &conn_iter)
848		if (connector->encoder && connector->encoder->crtc == crtc)
849			if (connector->dpms < dpms)
850				dpms = connector->dpms;
851	drm_connector_list_iter_end(&conn_iter);
852
853	return dpms;
854}
855
856/**
857 * drm_helper_connector_dpms() - connector dpms helper implementation
858 * @connector: affected connector
859 * @mode: DPMS mode
860 *
861 * The drm_helper_connector_dpms() helper function implements the
862 * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
863 * helpers.
864 *
865 * This is the main helper function provided by the CRTC helper framework for
866 * implementing the DPMS connector attribute. It computes the new desired DPMS
867 * state for all encoders and CRTCs in the output mesh and calls the
868 * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
869 * provided by the driver.
870 *
871 * This function is deprecated.  New drivers must implement atomic modeset
872 * support, where DPMS is handled in the DRM core.
873 *
874 * Returns:
875 * Always returns 0.
876 */
877int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
878{
879	struct drm_encoder *encoder = connector->encoder;
880	struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
881	int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
882
883	WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
884
885	if (mode == connector->dpms)
886		return 0;
887
888	old_dpms = connector->dpms;
889	connector->dpms = mode;
890
891	if (encoder)
892		encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
893
894	/* from off to on, do crtc then encoder */
895	if (mode < old_dpms) {
896		if (crtc) {
897			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
898			if (crtc_funcs->dpms)
899				(*crtc_funcs->dpms) (crtc,
900						     drm_helper_choose_crtc_dpms(crtc));
901		}
902		if (encoder)
903			drm_helper_encoder_dpms(encoder, encoder_dpms);
904	}
905
906	/* from on to off, do encoder then crtc */
907	if (mode > old_dpms) {
908		if (encoder)
909			drm_helper_encoder_dpms(encoder, encoder_dpms);
910		if (crtc) {
911			const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
912			if (crtc_funcs->dpms)
913				(*crtc_funcs->dpms) (crtc,
914						     drm_helper_choose_crtc_dpms(crtc));
915		}
916	}
917
918	return 0;
919}
920EXPORT_SYMBOL(drm_helper_connector_dpms);
921
922/**
923 * drm_helper_resume_force_mode - force-restore mode setting configuration
924 * @dev: drm_device which should be restored
925 *
926 * Drivers which use the mode setting helpers can use this function to
927 * force-restore the mode setting configuration e.g. on resume or when something
928 * else might have trampled over the hw state (like some overzealous old BIOSen
929 * tended to do).
930 *
931 * This helper doesn't provide a error return value since restoring the old
932 * config should never fail due to resource allocation issues since the driver
933 * has successfully set the restored configuration already. Hence this should
934 * boil down to the equivalent of a few dpms on calls, which also don't provide
935 * an error code.
936 *
937 * Drivers where simply restoring an old configuration again might fail (e.g.
938 * due to slight differences in allocating shared resources when the
939 * configuration is restored in a different order than when userspace set it up)
940 * need to use their own restore logic.
941 *
942 * This function is deprecated. New drivers should implement atomic mode-
943 * setting and use the atomic suspend/resume helpers.
944 *
945 * See also:
946 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
947 */
948void drm_helper_resume_force_mode(struct drm_device *dev)
949{
950	struct drm_crtc *crtc;
951	struct drm_encoder *encoder;
952	const struct drm_crtc_helper_funcs *crtc_funcs;
953	int encoder_dpms;
954	bool ret;
955
956	WARN_ON(drm_drv_uses_atomic_modeset(dev));
957
958	drm_modeset_lock_all(dev);
959	drm_for_each_crtc(crtc, dev) {
960
961		if (!crtc->enabled)
962			continue;
963
964		ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
965					       crtc->x, crtc->y, crtc->primary->fb);
966
967		/* Restoring the old config should never fail! */
968		if (ret == false)
969			DRM_ERROR("failed to set mode on crtc %p\n", crtc);
970
971		/* Turn off outputs that were already powered off */
972		if (drm_helper_choose_crtc_dpms(crtc)) {
973			drm_for_each_encoder(encoder, dev) {
974
975				if(encoder->crtc != crtc)
976					continue;
977
978				encoder_dpms = drm_helper_choose_encoder_dpms(
979							encoder);
980
981				drm_helper_encoder_dpms(encoder, encoder_dpms);
982			}
983
984			crtc_funcs = crtc->helper_private;
985			if (crtc_funcs->dpms)
986				(*crtc_funcs->dpms) (crtc,
987						     drm_helper_choose_crtc_dpms(crtc));
988		}
989	}
990
991	/* disable the unused connectors while restoring the modesetting */
992	__drm_helper_disable_unused_functions(dev);
993	drm_modeset_unlock_all(dev);
994}
995EXPORT_SYMBOL(drm_helper_resume_force_mode);
996
997/**
998 * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
999 * @dev: DRM device whose CRTCs to turn off
1000 *
1001 * Drivers may want to call this on unload to ensure that all displays are
1002 * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
1003 *
1004 * Note: This should only be used by non-atomic legacy drivers. For an atomic
1005 * version look at drm_atomic_helper_shutdown().
1006 *
1007 * Returns:
1008 * Zero on success, error code on failure.
1009 */
1010int drm_helper_force_disable_all(struct drm_device *dev)
1011{
1012	struct drm_crtc *crtc;
1013	int ret = 0;
1014
1015	drm_modeset_lock_all(dev);
1016	drm_for_each_crtc(crtc, dev)
1017		if (crtc->enabled) {
1018			struct drm_mode_set set = {
1019				.crtc = crtc,
1020			};
1021
1022			ret = drm_mode_set_config_internal(&set);
1023			if (ret)
1024				goto out;
1025		}
1026out:
1027	drm_modeset_unlock_all(dev);
1028	return ret;
1029}
1030EXPORT_SYMBOL(drm_helper_force_disable_all);
1031