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_bridge.h>
  30 #include <drm/drm_connector.h>
  31 #include <drm/drm_crtc.h>
  32 #include <drm/drm_device.h>
  33 #include <drm/drm_plane.h>
  34 #include <drm/drm_print.h>
  35 #include <drm/drm_vblank.h>
  36 #include <drm/drm_writeback.h>
  37
  38 #include <linux/slab.h>
  39 #include <linux/dma-fence.h>
  40
  41 /**
  42  * DOC: atomic state reset and initialization
  43  *
  44  * Both the drm core and the atomic helpers assume that there is always the full
  45  * and correct atomic software state for all connectors, CRTCs and planes
  46  * available. Which is a bit a problem on driver load and also after system
  47  * suspend. One way to solve this is to have a hardware state read-out
  48  * infrastructure which reconstructs the full software state (e.g. the i915
  49  * driver).
  50  *
  51  * The simpler solution is to just reset the software state to everything off,
  52  * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
  53  * the atomic helpers provide default reset implementations for all hooks.
  54  *
  55  * On the upside the precise state tracking of atomic simplifies system suspend
  56  * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
  57  * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
  58  * For other drivers the building blocks are split out, see the documentation
  59  * for these functions.
  60  */
  61
  62 /**
  63  * __drm_atomic_helper_crtc_state_reset - reset the CRTC state
  64  * @crtc_state: atomic CRTC state, must not be NULL
  65  * @crtc: CRTC object, must not be NULL
  66  *
  67  * Initializes the newly allocated @crtc_state with default
  68  * values. This is useful for drivers that subclass the CRTC state.
  69  */
  70 void
  71 __drm_atomic_helper_crtc_state_reset(struct drm_crtc_state *crtc_state,
  72                                      struct drm_crtc *crtc)
  73 {
  74         crtc_state->crtc = crtc;
  75 }
  76 EXPORT_SYMBOL(__drm_atomic_helper_crtc_state_reset);
  77
  78 /**
  79  * __drm_atomic_helper_crtc_reset - reset state on CRTC
  80  * @crtc: drm CRTC
  81  * @crtc_state: CRTC state to assign
  82  *
  83  * Initializes the newly allocated @crtc_state and assigns it to
  84  * the &drm_crtc->state pointer of @crtc, usually required when
  85  * initializing the drivers or when called from the &drm_crtc_funcs.reset
  86  * hook.
  87  *
  88  * This is useful for drivers that subclass the CRTC state.
  89  */
  90 void
  91 __drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
  92                                struct drm_crtc_state *crtc_state)
  93 {
  94         if (crtc_state)
  95                 __drm_atomic_helper_crtc_state_reset(crtc_state, crtc);
  96
  97         if (drm_dev_has_vblank(crtc->dev))
  98                 drm_crtc_vblank_reset(crtc);
  99
 100         crtc->state = crtc_state;
 101 }
 102 EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset);
 103
 104 /**
 105  * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
 106  * @crtc: drm CRTC
 107  *
 108  * Resets the atomic state for @crtc by freeing the state pointer (which might
 109  * be NULL, e.g. at driver load time) and allocating a new empty state object.
 110  */
 111 void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
 112 {
 113         struct drm_crtc_state *crtc_state =
 114                 kzalloc(sizeof(*crtc->state), GFP_KERNEL);
 115
 116         if (crtc->state)
 117                 crtc->funcs->atomic_destroy_state(crtc, crtc->state);
 118
 119         __drm_atomic_helper_crtc_reset(crtc, crtc_state);
 120 }
 121 EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
 122
 123 /**
 124  * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
 125  * @crtc: CRTC object
 126  * @state: atomic CRTC state
 127  *
 128  * Copies atomic state from a CRTC's current state and resets inferred values.
 129  * This is useful for drivers that subclass the CRTC state.
 130  */
 131 void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
 132                                               struct drm_crtc_state *state)
 133 {
 134         memcpy(state, crtc->state, sizeof(*state));
 135
 136         if (state->mode_blob)
 137                 drm_property_blob_get(state->mode_blob);
 138         if (state->degamma_lut)
 139                 drm_property_blob_get(state->degamma_lut);
 140         if (state->ctm)
 141                 drm_property_blob_get(state->ctm);
 142         if (state->gamma_lut)
 143                 drm_property_blob_get(state->gamma_lut);
 144         state->mode_changed = false;
 145         state->active_changed = false;
 146         state->planes_changed = false;
 147         state->connectors_changed = false;
 148         state->color_mgmt_changed = false;
 149         state->zpos_changed = false;
 150         state->commit = NULL;
 151         state->event = NULL;
 152         state->async_flip = false;
 153
 154         /* Self refresh should be canceled when a new update is available */
 155         state->active = drm_atomic_crtc_effectively_active(state);
 156         state->self_refresh_active = false;
 157 }
 158 EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
 159
 160 /**
 161  * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
 162  * @crtc: drm CRTC
 163  *
 164  * Default CRTC state duplicate hook for drivers which don't have their own
 165  * subclassed CRTC state structure.
 166  */
 167 struct drm_crtc_state *
 168 drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
 169 {
 170         struct drm_crtc_state *state;
 171
 172         if (WARN_ON(!crtc->state))
 173                 return NULL;
 174
 175         state = kmalloc(sizeof(*state), GFP_KERNEL);
 176         if (state)
 177                 __drm_atomic_helper_crtc_duplicate_state(crtc, state);
 178
 179         return state;
 180 }
 181 EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
 182
 183 /**
 184  * __drm_atomic_helper_crtc_destroy_state - release CRTC state
 185  * @state: CRTC state object to release
 186  *
 187  * Releases all resources stored in the CRTC state without actually freeing
 188  * the memory of the CRTC state. This is useful for drivers that subclass the
 189  * CRTC state.
 190  */
 191 void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
 192 {
 193         if (state->commit) {
 194                 /*
 195                  * In the event that a non-blocking commit returns
 196                  * -ERESTARTSYS before the commit_tail work is queued, we will
 197                  * have an extra reference to the commit object. Release it, if
 198                  * the event has not been consumed by the worker.
 199                  *
 200                  * state->event may be freed, so we can't directly look at
 201                  * state->event->base.completion.
 202                  */
 203                 if (state->event && state->commit->abort_completion)
 204                         drm_crtc_commit_put(state->commit);
 205
 206                 kfree(state->commit->event);
 207                 state->commit->event = NULL;
 208
 209                 drm_crtc_commit_put(state->commit);
 210         }
 211
 212         drm_property_blob_put(state->mode_blob);
 213         drm_property_blob_put(state->degamma_lut);
 214         drm_property_blob_put(state->ctm);
 215         drm_property_blob_put(state->gamma_lut);
 216 }
 217 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 218
 219 /**
 220  * drm_atomic_helper_crtc_destroy_state - default state destroy hook
 221  * @crtc: drm CRTC
 222  * @state: CRTC state object to release
 223  *
 224  * Default CRTC state destroy hook for drivers which don't have their own
 225  * subclassed CRTC state structure.
 226  */
 227 void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
 228                                           struct drm_crtc_state *state)
 229 {
 230         __drm_atomic_helper_crtc_destroy_state(state);
 231         kfree(state);
 232 }
 233 EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
 234
 235 /**
 236  * __drm_atomic_helper_plane_state_reset - resets plane state to default values
 237  * @plane_state: atomic plane state, must not be NULL
 238  * @plane: plane object, must not be NULL
 239  *
 240  * Initializes the newly allocated @plane_state with default
 241  * values. This is useful for drivers that subclass the CRTC state.
 242  */
 243 void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
 244                                            struct drm_plane *plane)
 245 {
 246         u64 val;
 247
 248         plane_state->plane = plane;
 249         plane_state->rotation = DRM_MODE_ROTATE_0;
 250
 251         plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
 252         plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
 253
 254         if (plane->color_encoding_property) {
 255                 if (!drm_object_property_get_default_value(&plane->base,
 256                                                            plane->color_encoding_property,
 257                                                            &val))
 258                         plane_state->color_encoding = val;
 259         }
 260
 261         if (plane->color_range_property) {
 262                 if (!drm_object_property_get_default_value(&plane->base,
 263                                                            plane->color_range_property,
 264                                                            &val))
 265                         plane_state->color_range = val;
 266         }
 267
 268         if (plane->chroma_siting_h_property) {
 269                 if (!drm_object_property_get_default_value(&plane->base,
 270                                                            plane->chroma_siting_h_property,
 271                                                            &val))
 272                         plane_state->chroma_siting_h = val;
 273         }
 274
 275         if (plane->chroma_siting_v_property) {
 276                 if (!drm_object_property_get_default_value(&plane->base,
 277                                                            plane->chroma_siting_v_property,
 278                                                            &val))
 279                         plane_state->chroma_siting_v = val;
 280         }
 281
 282         if (plane->zpos_property) {
 283                 if (!drm_object_property_get_default_value(&plane->base,
 284                                                            plane->zpos_property,
 285                                                            &val)) {
 286                         plane_state->zpos = val;
 287                         plane_state->normalized_zpos = val;
 288                 }
 289         }
 290 }
 291 EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
 292
 293 /**
 294  * __drm_atomic_helper_plane_reset - reset state on plane
 295  * @plane: drm plane
 296  * @plane_state: plane state to assign
 297  *
 298  * Initializes the newly allocated @plane_state and assigns it to
 299  * the &drm_crtc->state pointer of @plane, usually required when
 300  * initializing the drivers or when called from the &drm_plane_funcs.reset
 301  * hook.
 302  *
 303  * This is useful for drivers that subclass the plane state.
 304  */
 305 void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
 306                                      struct drm_plane_state *plane_state)
 307 {
 308         if (plane_state)
 309                 __drm_atomic_helper_plane_state_reset(plane_state, plane);
 310
 311         plane->state = plane_state;
 312 }
 313 EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
 314
 315 /**
 316  * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
 317  * @plane: drm plane
 318  *
 319  * Resets the atomic state for @plane by freeing the state pointer (which might
 320  * be NULL, e.g. at driver load time) and allocating a new empty state object.
 321  */
 322 void drm_atomic_helper_plane_reset(struct drm_plane *plane)
 323 {
 324         if (plane->state)
 325                 __drm_atomic_helper_plane_destroy_state(plane->state);
 326
 327         kfree(plane->state);
 328         plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
 329         if (plane->state)
 330                 __drm_atomic_helper_plane_reset(plane, plane->state);
 331 }
 332 EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
 333
 334 /**
 335  * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 336  * @plane: plane object
 337  * @state: atomic plane state
 338  *
 339  * Copies atomic state from a plane's current state. This is useful for
 340  * drivers that subclass the plane state.
 341  */
 342 void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 343                                                struct drm_plane_state *state)
 344 {
 345         memcpy(state, plane->state, sizeof(*state));
 346
 347         if (state->fb)
 348                 drm_framebuffer_get(state->fb);
 349
 350         state->fence = NULL;
 351         state->commit = NULL;
 352         state->fb_damage_clips = NULL;
 353 }
 354 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
 355
 356 /**
 357  * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 358  * @plane: drm plane
 359  *
 360  * Default plane state duplicate hook for drivers which don't have their own
 361  * subclassed plane state structure.
 362  */
 363 struct drm_plane_state *
 364 drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
 365 {
 366         struct drm_plane_state *state;
 367
 368         if (WARN_ON(!plane->state))
 369                 return NULL;
 370
 371         state = kmalloc(sizeof(*state), GFP_KERNEL);
 372         if (state)
 373                 __drm_atomic_helper_plane_duplicate_state(plane, state);
 374
 375         return state;
 376 }
 377 EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
 378
 379 /**
 380  * __drm_atomic_helper_plane_destroy_state - release plane state
 381  * @state: plane state object to release
 382  *
 383  * Releases all resources stored in the plane state without actually freeing
 384  * the memory of the plane state. This is useful for drivers that subclass the
 385  * plane state.
 386  */
 387 void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
 388 {
 389         if (state->fb)
 390                 drm_framebuffer_put(state->fb);
 391
 392         if (state->fence)
 393                 dma_fence_put(state->fence);
 394
 395         if (state->commit)
 396                 drm_crtc_commit_put(state->commit);
 397
 398         drm_property_blob_put(state->fb_damage_clips);
 399 }
 400 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
 401
 402 /**
 403  * drm_atomic_helper_plane_destroy_state - default state destroy hook
 404  * @plane: drm plane
 405  * @state: plane state object to release
 406  *
 407  * Default plane state destroy hook for drivers which don't have their own
 408  * subclassed plane state structure.
 409  */
 410 void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
 411                                            struct drm_plane_state *state)
 412 {
 413         __drm_atomic_helper_plane_destroy_state(state);
 414         kfree(state);
 415 }
 416 EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
 417
 418 /**
 419  * __drm_atomic_helper_connector_state_reset - reset the connector state
 420  * @conn_state: atomic connector state, must not be NULL
 421  * @connector: connectotr object, must not be NULL
 422  *
 423  * Initializes the newly allocated @conn_state with default
 424  * values. This is useful for drivers that subclass the connector state.
 425  */
 426 void
 427 __drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
 428                                           struct drm_connector *connector)
 429 {
 430         conn_state->connector = connector;
 431 }
 432 EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);
 433
 434 /**
 435  * __drm_atomic_helper_connector_reset - reset state on connector
 436  * @connector: drm connector
 437  * @conn_state: connector state to assign
 438  *
 439  * Initializes the newly allocated @conn_state and assigns it to
 440  * the &drm_connector->state pointer of @connector, usually required when
 441  * initializing the drivers or when called from the &drm_connector_funcs.reset
 442  * hook.
 443  *
 444  * This is useful for drivers that subclass the connector state.
 445  */
 446 void
 447 __drm_atomic_helper_connector_reset(struct drm_connector *connector,
 448                                     struct drm_connector_state *conn_state)
 449 {
 450         if (conn_state)
 451                 __drm_atomic_helper_connector_state_reset(conn_state, connector);
 452
 453         connector->state = conn_state;
 454 }
 455 EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
 456
 457 /**
 458  * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
 459  * @connector: drm connector
 460  *
 461  * Resets the atomic state for @connector by freeing the state pointer (which
 462  * might be NULL, e.g. at driver load time) and allocating a new empty state
 463  * object.
 464  */
 465 void drm_atomic_helper_connector_reset(struct drm_connector *connector)
 466 {
 467         struct drm_connector_state *conn_state =
 468                 kzalloc(sizeof(*conn_state), GFP_KERNEL);
 469
 470         if (connector->state)
 471                 __drm_atomic_helper_connector_destroy_state(connector->state);
 472
 473         kfree(connector->state);
 474         __drm_atomic_helper_connector_reset(connector, conn_state);
 475 }
 476 EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
 477
 478 /**
 479  * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
 480  * @connector: DRM connector
 481  *
 482  * Resets the TV-related properties attached to a connector.
 483  */
 484 void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
 485 {
 486         struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
 487         struct drm_connector_state *state = connector->state;
 488
 489         state->tv.margins.left = cmdline->tv_margins.left;
 490         state->tv.margins.right = cmdline->tv_margins.right;
 491         state->tv.margins.top = cmdline->tv_margins.top;
 492         state->tv.margins.bottom = cmdline->tv_margins.bottom;
 493 }
 494 EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
 495
 496 /**
 497  * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 498  * @connector: connector object
 499  * @state: atomic connector state
 500  *
 501  * Copies atomic state from a connector's current state. This is useful for
 502  * drivers that subclass the connector state.
 503  */
 504 void
 505 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
 506                                             struct drm_connector_state *state)
 507 {
 508         memcpy(state, connector->state, sizeof(*state));
 509         if (state->crtc)
 510                 drm_connector_get(connector);
 511         state->commit = NULL;
 512
 513         if (state->hdr_output_metadata)
 514                 drm_property_blob_get(state->hdr_output_metadata);
 515
 516         /* Don't copy over a writeback job, they are used only once */
 517         state->writeback_job = NULL;
 518 }
 519 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 520
 521 /**
 522  * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 523  * @connector: drm connector
 524  *
 525  * Default connector state duplicate hook for drivers which don't have their own
 526  * subclassed connector state structure.
 527  */
 528 struct drm_connector_state *
 529 drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
 530 {
 531         struct drm_connector_state *state;
 532
 533         if (WARN_ON(!connector->state))
 534                 return NULL;
 535
 536         state = kmalloc(sizeof(*state), GFP_KERNEL);
 537         if (state)
 538                 __drm_atomic_helper_connector_duplicate_state(connector, state);
 539
 540         return state;
 541 }
 542 EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
 543
 544 /**
 545  * __drm_atomic_helper_connector_destroy_state - release connector state
 546  * @state: connector state object to release
 547  *
 548  * Releases all resources stored in the connector state without actually
 549  * freeing the memory of the connector state. This is useful for drivers that
 550  * subclass the connector state.
 551  */
 552 void
 553 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
 554 {
 555         if (state->crtc)
 556                 drm_connector_put(state->connector);
 557
 558         if (state->commit)
 559                 drm_crtc_commit_put(state->commit);
 560
 561         if (state->writeback_job)
 562                 drm_writeback_cleanup_job(state->writeback_job);
 563
 564         drm_property_blob_put(state->hdr_output_metadata);
 565 }
 566 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
 567
 568 /**
 569  * drm_atomic_helper_connector_destroy_state - default state destroy hook
 570  * @connector: drm connector
 571  * @state: connector state object to release
 572  *
 573  * Default connector state destroy hook for drivers which don't have their own
 574  * subclassed connector state structure.
 575  */
 576 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 577                                           struct drm_connector_state *state)
 578 {
 579         __drm_atomic_helper_connector_destroy_state(state);
 580         kfree(state);
 581 }
 582 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
 583
 584 /**
 585  * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
 586  * @obj: CRTC object
 587  * @state: new private object state
 588  *
 589  * Copies atomic state from a private objects's current state and resets inferred values.
 590  * This is useful for drivers that subclass the private state.
 591  */
 592 void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
 593                                                      struct drm_private_state *state)
 594 {
 595         memcpy(state, obj->state, sizeof(*state));
 596 }
 597 EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
 598
 599 /**
 600  * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
 601  * @bridge: bridge object
 602  * @state: atomic bridge state
 603  *
 604  * Copies atomic state from a bridge's current state and resets inferred values.
 605  * This is useful for drivers that subclass the bridge state.
 606  */
 607 void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
 608                                                 struct drm_bridge_state *state)
 609 {
 610         __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
 611                                                         &state->base);
 612         state->bridge = bridge;
 613 }
 614 EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
 615
 616 /**
 617  * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
 618  * @bridge: bridge object
 619  *
 620  * Allocates a new bridge state and initializes it with the current bridge
 621  * state values. This helper is meant to be used as a bridge
 622  * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
 623  * subclass the bridge state.
 624  */
 625 struct drm_bridge_state *
 626 drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
 627 {
 628         struct drm_bridge_state *new;
 629
 630         if (WARN_ON(!bridge->base.state))
 631                 return NULL;
 632
 633         new = kzalloc(sizeof(*new), GFP_KERNEL);
 634         if (new)
 635                 __drm_atomic_helper_bridge_duplicate_state(bridge, new);
 636
 637         return new;
 638 }
 639 EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
 640
 641 /**
 642  * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
 643  * @bridge: the bridge this state refers to
 644  * @state: bridge state to destroy
 645  *
 646  * Destroys a bridge state previously created by
 647  * &drm_atomic_helper_bridge_reset() or
 648  * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
 649  * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
 650  * that don't subclass the bridge state.
 651  */
 652 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
 653                                             struct drm_bridge_state *state)
 654 {
 655         kfree(state);
 656 }
 657 EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
 658
 659 /**
 660  * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
 661  *                                      default
 662  * @bridge: the bridge this state refers to
 663  * @state: bridge state to initialize
 664  *
 665  * Initializes the bridge state to default values. This is meant to be called
 666  * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
 667  * the bridge state.
 668  */
 669 void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
 670                                       struct drm_bridge_state *state)
 671 {
 672         memset(state, 0, sizeof(*state));
 673         state->bridge = bridge;
 674 }
 675 EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
 676
 677 /**
 678  * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
 679  *                                    to its default
 680  * @bridge: the bridge this state refers to
 681  *
 682  * Allocates the bridge state and initializes it to default values. This helper
 683  * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
 684  * bridges that don't subclass the bridge state.
 685  */
 686 struct drm_bridge_state *
 687 drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
 688 {
 689         struct drm_bridge_state *bridge_state;
 690
 691         bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
 692         if (!bridge_state)
 693                 return ERR_PTR(-ENOMEM);
 694
 695         __drm_atomic_helper_bridge_reset(bridge, bridge_state);
 696         return bridge_state;
 697 }
 698 EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);