Merge tag 'mediatek-drm-next-5.20' of https://git.kernel.org/pub/scm/linux/kernel...
[platform/kernel/linux-starfive.git] / drivers / gpu / drm / drm_atomic_state_helper.c
1 /*
2  * Copyright (C) 2018 Intel Corp.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors:
23  * Rob Clark <robdclark@gmail.com>
24  * Daniel Vetter <daniel.vetter@ffwll.ch>
25  */
26
27 #include <drm/drm_atomic.h>
28 #include <drm/drm_atomic_state_helper.h>
29 #include <drm/drm_blend.h>
30 #include <drm/drm_bridge.h>
31 #include <drm/drm_connector.h>
32 #include <drm/drm_crtc.h>
33 #include <drm/drm_device.h>
34 #include <drm/drm_framebuffer.h>
35 #include <drm/drm_plane.h>
36 #include <drm/drm_print.h>
37 #include <drm/drm_vblank.h>
38 #include <drm/drm_writeback.h>
39
40 #include <linux/slab.h>
41 #include <linux/dma-fence.h>
42
43 /**
44  * DOC: atomic state reset and initialization
45  *
46  * Both the drm core and the atomic helpers assume that there is always the full
47  * and correct atomic software state for all connectors, CRTCs and planes
48  * available. Which is a bit a problem on driver load and also after system
49  * suspend. One way to solve this is to have a hardware state read-out
50  * infrastructure which reconstructs the full software state (e.g. the i915
51  * driver).
52  *
53  * The simpler solution is to just reset the software state to everything off,
54  * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
55  * the atomic helpers provide default reset implementations for all hooks.
56  *
57  * On the upside the precise state tracking of atomic simplifies system suspend
58  * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
59  * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
60  * For other drivers the building blocks are split out, see the documentation
61  * for these functions.
62  */
63
64 /**
65  * __drm_atomic_helper_crtc_state_reset - reset the CRTC state
66  * @crtc_state: atomic CRTC state, must not be NULL
67  * @crtc: CRTC object, must not be NULL
68  *
69  * Initializes the newly allocated @crtc_state with default
70  * values. This is useful for drivers that subclass the CRTC state.
71  */
72 void
73 __drm_atomic_helper_crtc_state_reset(struct drm_crtc_state *crtc_state,
74                                      struct drm_crtc *crtc)
75 {
76         crtc_state->crtc = crtc;
77 }
78 EXPORT_SYMBOL(__drm_atomic_helper_crtc_state_reset);
79
80 /**
81  * __drm_atomic_helper_crtc_reset - reset state on CRTC
82  * @crtc: drm CRTC
83  * @crtc_state: CRTC state to assign
84  *
85  * Initializes the newly allocated @crtc_state and assigns it to
86  * the &drm_crtc->state pointer of @crtc, usually required when
87  * initializing the drivers or when called from the &drm_crtc_funcs.reset
88  * hook.
89  *
90  * This is useful for drivers that subclass the CRTC state.
91  */
92 void
93 __drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
94                                struct drm_crtc_state *crtc_state)
95 {
96         if (crtc_state)
97                 __drm_atomic_helper_crtc_state_reset(crtc_state, crtc);
98
99         if (drm_dev_has_vblank(crtc->dev))
100                 drm_crtc_vblank_reset(crtc);
101
102         crtc->state = crtc_state;
103 }
104 EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset);
105
106 /**
107  * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
108  * @crtc: drm CRTC
109  *
110  * Resets the atomic state for @crtc by freeing the state pointer (which might
111  * be NULL, e.g. at driver load time) and allocating a new empty state object.
112  */
113 void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
114 {
115         struct drm_crtc_state *crtc_state =
116                 kzalloc(sizeof(*crtc->state), GFP_KERNEL);
117
118         if (crtc->state)
119                 crtc->funcs->atomic_destroy_state(crtc, crtc->state);
120
121         __drm_atomic_helper_crtc_reset(crtc, crtc_state);
122 }
123 EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
124
125 /**
126  * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
127  * @crtc: CRTC object
128  * @state: atomic CRTC state
129  *
130  * Copies atomic state from a CRTC's current state and resets inferred values.
131  * This is useful for drivers that subclass the CRTC state.
132  */
133 void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
134                                               struct drm_crtc_state *state)
135 {
136         memcpy(state, crtc->state, sizeof(*state));
137
138         if (state->mode_blob)
139                 drm_property_blob_get(state->mode_blob);
140         if (state->degamma_lut)
141                 drm_property_blob_get(state->degamma_lut);
142         if (state->ctm)
143                 drm_property_blob_get(state->ctm);
144         if (state->gamma_lut)
145                 drm_property_blob_get(state->gamma_lut);
146         state->mode_changed = false;
147         state->active_changed = false;
148         state->planes_changed = false;
149         state->connectors_changed = false;
150         state->color_mgmt_changed = false;
151         state->zpos_changed = false;
152         state->commit = NULL;
153         state->event = NULL;
154         state->async_flip = false;
155
156         /* Self refresh should be canceled when a new update is available */
157         state->active = drm_atomic_crtc_effectively_active(state);
158         state->self_refresh_active = false;
159 }
160 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
161
162 /**
163  * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
164  * @crtc: drm CRTC
165  *
166  * Default CRTC state duplicate hook for drivers which don't have their own
167  * subclassed CRTC state structure.
168  */
169 struct drm_crtc_state *
170 drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
171 {
172         struct drm_crtc_state *state;
173
174         if (WARN_ON(!crtc->state))
175                 return NULL;
176
177         state = kmalloc(sizeof(*state), GFP_KERNEL);
178         if (state)
179                 __drm_atomic_helper_crtc_duplicate_state(crtc, state);
180
181         return state;
182 }
183 EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
184
185 /**
186  * __drm_atomic_helper_crtc_destroy_state - release CRTC state
187  * @state: CRTC state object to release
188  *
189  * Releases all resources stored in the CRTC state without actually freeing
190  * the memory of the CRTC state. This is useful for drivers that subclass the
191  * CRTC state.
192  */
193 void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
194 {
195         if (state->commit) {
196                 /*
197                  * In the event that a non-blocking commit returns
198                  * -ERESTARTSYS before the commit_tail work is queued, we will
199                  * have an extra reference to the commit object. Release it, if
200                  * the event has not been consumed by the worker.
201                  *
202                  * state->event may be freed, so we can't directly look at
203                  * state->event->base.completion.
204                  */
205                 if (state->event && state->commit->abort_completion)
206                         drm_crtc_commit_put(state->commit);
207
208                 kfree(state->commit->event);
209                 state->commit->event = NULL;
210
211                 drm_crtc_commit_put(state->commit);
212         }
213
214         drm_property_blob_put(state->mode_blob);
215         drm_property_blob_put(state->degamma_lut);
216         drm_property_blob_put(state->ctm);
217         drm_property_blob_put(state->gamma_lut);
218 }
219 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
220
221 /**
222  * drm_atomic_helper_crtc_destroy_state - default state destroy hook
223  * @crtc: drm CRTC
224  * @state: CRTC state object to release
225  *
226  * Default CRTC state destroy hook for drivers which don't have their own
227  * subclassed CRTC state structure.
228  */
229 void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
230                                           struct drm_crtc_state *state)
231 {
232         __drm_atomic_helper_crtc_destroy_state(state);
233         kfree(state);
234 }
235 EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
236
237 /**
238  * __drm_atomic_helper_plane_state_reset - resets plane state to default values
239  * @plane_state: atomic plane state, must not be NULL
240  * @plane: plane object, must not be NULL
241  *
242  * Initializes the newly allocated @plane_state with default
243  * values. This is useful for drivers that subclass the CRTC state.
244  */
245 void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
246                                            struct drm_plane *plane)
247 {
248         u64 val;
249
250         plane_state->plane = plane;
251         plane_state->rotation = DRM_MODE_ROTATE_0;
252
253         plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
254         plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
255
256         if (plane->color_encoding_property) {
257                 if (!drm_object_property_get_default_value(&plane->base,
258                                                            plane->color_encoding_property,
259                                                            &val))
260                         plane_state->color_encoding = val;
261         }
262
263         if (plane->color_range_property) {
264                 if (!drm_object_property_get_default_value(&plane->base,
265                                                            plane->color_range_property,
266                                                            &val))
267                         plane_state->color_range = val;
268         }
269
270         if (plane->zpos_property) {
271                 if (!drm_object_property_get_default_value(&plane->base,
272                                                            plane->zpos_property,
273                                                            &val)) {
274                         plane_state->zpos = val;
275                         plane_state->normalized_zpos = val;
276                 }
277         }
278 }
279 EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
280
281 /**
282  * __drm_atomic_helper_plane_reset - reset state on plane
283  * @plane: drm plane
284  * @plane_state: plane state to assign
285  *
286  * Initializes the newly allocated @plane_state and assigns it to
287  * the &drm_crtc->state pointer of @plane, usually required when
288  * initializing the drivers or when called from the &drm_plane_funcs.reset
289  * hook.
290  *
291  * This is useful for drivers that subclass the plane state.
292  */
293 void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
294                                      struct drm_plane_state *plane_state)
295 {
296         if (plane_state)
297                 __drm_atomic_helper_plane_state_reset(plane_state, plane);
298
299         plane->state = plane_state;
300 }
301 EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
302
303 /**
304  * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
305  * @plane: drm plane
306  *
307  * Resets the atomic state for @plane by freeing the state pointer (which might
308  * be NULL, e.g. at driver load time) and allocating a new empty state object.
309  */
310 void drm_atomic_helper_plane_reset(struct drm_plane *plane)
311 {
312         if (plane->state)
313                 __drm_atomic_helper_plane_destroy_state(plane->state);
314
315         kfree(plane->state);
316         plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
317         if (plane->state)
318                 __drm_atomic_helper_plane_reset(plane, plane->state);
319 }
320 EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
321
322 /**
323  * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
324  * @plane: plane object
325  * @state: atomic plane state
326  *
327  * Copies atomic state from a plane's current state. This is useful for
328  * drivers that subclass the plane state.
329  */
330 void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
331                                                struct drm_plane_state *state)
332 {
333         memcpy(state, plane->state, sizeof(*state));
334
335         if (state->fb)
336                 drm_framebuffer_get(state->fb);
337
338         state->fence = NULL;
339         state->commit = NULL;
340         state->fb_damage_clips = NULL;
341 }
342 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
343
344 /**
345  * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
346  * @plane: drm plane
347  *
348  * Default plane state duplicate hook for drivers which don't have their own
349  * subclassed plane state structure.
350  */
351 struct drm_plane_state *
352 drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
353 {
354         struct drm_plane_state *state;
355
356         if (WARN_ON(!plane->state))
357                 return NULL;
358
359         state = kmalloc(sizeof(*state), GFP_KERNEL);
360         if (state)
361                 __drm_atomic_helper_plane_duplicate_state(plane, state);
362
363         return state;
364 }
365 EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
366
367 /**
368  * __drm_atomic_helper_plane_destroy_state - release plane state
369  * @state: plane state object to release
370  *
371  * Releases all resources stored in the plane state without actually freeing
372  * the memory of the plane state. This is useful for drivers that subclass the
373  * plane state.
374  */
375 void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
376 {
377         if (state->fb)
378                 drm_framebuffer_put(state->fb);
379
380         if (state->fence)
381                 dma_fence_put(state->fence);
382
383         if (state->commit)
384                 drm_crtc_commit_put(state->commit);
385
386         drm_property_blob_put(state->fb_damage_clips);
387 }
388 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
389
390 /**
391  * drm_atomic_helper_plane_destroy_state - default state destroy hook
392  * @plane: drm plane
393  * @state: plane state object to release
394  *
395  * Default plane state destroy hook for drivers which don't have their own
396  * subclassed plane state structure.
397  */
398 void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
399                                            struct drm_plane_state *state)
400 {
401         __drm_atomic_helper_plane_destroy_state(state);
402         kfree(state);
403 }
404 EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
405
406 /**
407  * __drm_atomic_helper_connector_state_reset - reset the connector state
408  * @conn_state: atomic connector state, must not be NULL
409  * @connector: connectotr object, must not be NULL
410  *
411  * Initializes the newly allocated @conn_state with default
412  * values. This is useful for drivers that subclass the connector state.
413  */
414 void
415 __drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
416                                           struct drm_connector *connector)
417 {
418         conn_state->connector = connector;
419 }
420 EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);
421
422 /**
423  * __drm_atomic_helper_connector_reset - reset state on connector
424  * @connector: drm connector
425  * @conn_state: connector state to assign
426  *
427  * Initializes the newly allocated @conn_state and assigns it to
428  * the &drm_connector->state pointer of @connector, usually required when
429  * initializing the drivers or when called from the &drm_connector_funcs.reset
430  * hook.
431  *
432  * This is useful for drivers that subclass the connector state.
433  */
434 void
435 __drm_atomic_helper_connector_reset(struct drm_connector *connector,
436                                     struct drm_connector_state *conn_state)
437 {
438         if (conn_state)
439                 __drm_atomic_helper_connector_state_reset(conn_state, connector);
440
441         connector->state = conn_state;
442 }
443 EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
444
445 /**
446  * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
447  * @connector: drm connector
448  *
449  * Resets the atomic state for @connector by freeing the state pointer (which
450  * might be NULL, e.g. at driver load time) and allocating a new empty state
451  * object.
452  */
453 void drm_atomic_helper_connector_reset(struct drm_connector *connector)
454 {
455         struct drm_connector_state *conn_state =
456                 kzalloc(sizeof(*conn_state), GFP_KERNEL);
457
458         if (connector->state)
459                 __drm_atomic_helper_connector_destroy_state(connector->state);
460
461         kfree(connector->state);
462         __drm_atomic_helper_connector_reset(connector, conn_state);
463 }
464 EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
465
466 /**
467  * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
468  * @connector: DRM connector
469  *
470  * Resets the TV-related properties attached to a connector.
471  */
472 void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
473 {
474         struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
475         struct drm_connector_state *state = connector->state;
476
477         state->tv.margins.left = cmdline->tv_margins.left;
478         state->tv.margins.right = cmdline->tv_margins.right;
479         state->tv.margins.top = cmdline->tv_margins.top;
480         state->tv.margins.bottom = cmdline->tv_margins.bottom;
481 }
482 EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
483
484 /**
485  * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
486  * @connector: connector object
487  * @state: atomic connector state
488  *
489  * Copies atomic state from a connector's current state. This is useful for
490  * drivers that subclass the connector state.
491  */
492 void
493 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
494                                             struct drm_connector_state *state)
495 {
496         memcpy(state, connector->state, sizeof(*state));
497         if (state->crtc)
498                 drm_connector_get(connector);
499         state->commit = NULL;
500
501         if (state->hdr_output_metadata)
502                 drm_property_blob_get(state->hdr_output_metadata);
503
504         /* Don't copy over a writeback job, they are used only once */
505         state->writeback_job = NULL;
506 }
507 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
508
509 /**
510  * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
511  * @connector: drm connector
512  *
513  * Default connector state duplicate hook for drivers which don't have their own
514  * subclassed connector state structure.
515  */
516 struct drm_connector_state *
517 drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
518 {
519         struct drm_connector_state *state;
520
521         if (WARN_ON(!connector->state))
522                 return NULL;
523
524         state = kmalloc(sizeof(*state), GFP_KERNEL);
525         if (state)
526                 __drm_atomic_helper_connector_duplicate_state(connector, state);
527
528         return state;
529 }
530 EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
531
532 /**
533  * __drm_atomic_helper_connector_destroy_state - release connector state
534  * @state: connector state object to release
535  *
536  * Releases all resources stored in the connector state without actually
537  * freeing the memory of the connector state. This is useful for drivers that
538  * subclass the connector state.
539  */
540 void
541 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
542 {
543         if (state->crtc)
544                 drm_connector_put(state->connector);
545
546         if (state->commit)
547                 drm_crtc_commit_put(state->commit);
548
549         if (state->writeback_job)
550                 drm_writeback_cleanup_job(state->writeback_job);
551
552         drm_property_blob_put(state->hdr_output_metadata);
553 }
554 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
555
556 /**
557  * drm_atomic_helper_connector_destroy_state - default state destroy hook
558  * @connector: drm connector
559  * @state: connector state object to release
560  *
561  * Default connector state destroy hook for drivers which don't have their own
562  * subclassed connector state structure.
563  */
564 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
565                                           struct drm_connector_state *state)
566 {
567         __drm_atomic_helper_connector_destroy_state(state);
568         kfree(state);
569 }
570 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
571
572 /**
573  * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
574  * @obj: CRTC object
575  * @state: new private object state
576  *
577  * Copies atomic state from a private objects's current state and resets inferred values.
578  * This is useful for drivers that subclass the private state.
579  */
580 void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
581                                                      struct drm_private_state *state)
582 {
583         memcpy(state, obj->state, sizeof(*state));
584 }
585 EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
586
587 /**
588  * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
589  * @bridge: bridge object
590  * @state: atomic bridge state
591  *
592  * Copies atomic state from a bridge's current state and resets inferred values.
593  * This is useful for drivers that subclass the bridge state.
594  */
595 void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
596                                                 struct drm_bridge_state *state)
597 {
598         __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
599                                                         &state->base);
600         state->bridge = bridge;
601 }
602 EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
603
604 /**
605  * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
606  * @bridge: bridge object
607  *
608  * Allocates a new bridge state and initializes it with the current bridge
609  * state values. This helper is meant to be used as a bridge
610  * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
611  * subclass the bridge state.
612  */
613 struct drm_bridge_state *
614 drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
615 {
616         struct drm_bridge_state *new;
617
618         if (WARN_ON(!bridge->base.state))
619                 return NULL;
620
621         new = kzalloc(sizeof(*new), GFP_KERNEL);
622         if (new)
623                 __drm_atomic_helper_bridge_duplicate_state(bridge, new);
624
625         return new;
626 }
627 EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
628
629 /**
630  * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
631  * @bridge: the bridge this state refers to
632  * @state: bridge state to destroy
633  *
634  * Destroys a bridge state previously created by
635  * &drm_atomic_helper_bridge_reset() or
636  * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
637  * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
638  * that don't subclass the bridge state.
639  */
640 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
641                                             struct drm_bridge_state *state)
642 {
643         kfree(state);
644 }
645 EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
646
647 /**
648  * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
649  *                                      default
650  * @bridge: the bridge this state refers to
651  * @state: bridge state to initialize
652  *
653  * Initializes the bridge state to default values. This is meant to be called
654  * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
655  * the bridge state.
656  */
657 void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
658                                       struct drm_bridge_state *state)
659 {
660         memset(state, 0, sizeof(*state));
661         state->bridge = bridge;
662 }
663 EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
664
665 /**
666  * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
667  *                                    to its default
668  * @bridge: the bridge this state refers to
669  *
670  * Allocates the bridge state and initializes it to default values. This helper
671  * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
672  * bridges that don't subclass the bridge state.
673  */
674 struct drm_bridge_state *
675 drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
676 {
677         struct drm_bridge_state *bridge_state;
678
679         bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
680         if (!bridge_state)
681                 return ERR_PTR(-ENOMEM);
682
683         __drm_atomic_helper_bridge_reset(bridge, bridge_state);
684         return bridge_state;
685 }
686 EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);