linux/drivers/gpu/drm/drm_atomic_state_helper.c
<<
>>
Prefs
   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 */
  70void
  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}
  76EXPORT_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 */
  90void
  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}
 102EXPORT_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 */
 111void 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}
 121EXPORT_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 */
 131void __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}
 158EXPORT_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 */
 167struct drm_crtc_state *
 168drm_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}
 181EXPORT_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 */
 191void __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}
 217EXPORT_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 */
 227void 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}
 233EXPORT_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 */
 243void __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->zpos_property) {
 269                if (!drm_object_property_get_default_value(&plane->base,
 270                                                           plane->zpos_property,
 271                                                           &val)) {
 272                        plane_state->zpos = val;
 273                        plane_state->normalized_zpos = val;
 274                }
 275        }
 276}
 277EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
 278
 279/**
 280 * __drm_atomic_helper_plane_reset - reset state on plane
 281 * @plane: drm plane
 282 * @plane_state: plane state to assign
 283 *
 284 * Initializes the newly allocated @plane_state and assigns it to
 285 * the &drm_crtc->state pointer of @plane, usually required when
 286 * initializing the drivers or when called from the &drm_plane_funcs.reset
 287 * hook.
 288 *
 289 * This is useful for drivers that subclass the plane state.
 290 */
 291void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
 292                                     struct drm_plane_state *plane_state)
 293{
 294        if (plane_state)
 295                __drm_atomic_helper_plane_state_reset(plane_state, plane);
 296
 297        plane->state = plane_state;
 298}
 299EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
 300
 301/**
 302 * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
 303 * @plane: drm plane
 304 *
 305 * Resets the atomic state for @plane by freeing the state pointer (which might
 306 * be NULL, e.g. at driver load time) and allocating a new empty state object.
 307 */
 308void drm_atomic_helper_plane_reset(struct drm_plane *plane)
 309{
 310        if (plane->state)
 311                __drm_atomic_helper_plane_destroy_state(plane->state);
 312
 313        kfree(plane->state);
 314        plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
 315        if (plane->state)
 316                __drm_atomic_helper_plane_reset(plane, plane->state);
 317}
 318EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
 319
 320/**
 321 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
 322 * @plane: plane object
 323 * @state: atomic plane state
 324 *
 325 * Copies atomic state from a plane's current state. This is useful for
 326 * drivers that subclass the plane state.
 327 */
 328void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
 329                                               struct drm_plane_state *state)
 330{
 331        memcpy(state, plane->state, sizeof(*state));
 332
 333        if (state->fb)
 334                drm_framebuffer_get(state->fb);
 335
 336        state->fence = NULL;
 337        state->commit = NULL;
 338        state->fb_damage_clips = NULL;
 339}
 340EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
 341
 342/**
 343 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
 344 * @plane: drm plane
 345 *
 346 * Default plane state duplicate hook for drivers which don't have their own
 347 * subclassed plane state structure.
 348 */
 349struct drm_plane_state *
 350drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
 351{
 352        struct drm_plane_state *state;
 353
 354        if (WARN_ON(!plane->state))
 355                return NULL;
 356
 357        state = kmalloc(sizeof(*state), GFP_KERNEL);
 358        if (state)
 359                __drm_atomic_helper_plane_duplicate_state(plane, state);
 360
 361        return state;
 362}
 363EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
 364
 365/**
 366 * __drm_atomic_helper_plane_destroy_state - release plane state
 367 * @state: plane state object to release
 368 *
 369 * Releases all resources stored in the plane state without actually freeing
 370 * the memory of the plane state. This is useful for drivers that subclass the
 371 * plane state.
 372 */
 373void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
 374{
 375        if (state->fb)
 376                drm_framebuffer_put(state->fb);
 377
 378        if (state->fence)
 379                dma_fence_put(state->fence);
 380
 381        if (state->commit)
 382                drm_crtc_commit_put(state->commit);
 383
 384        drm_property_blob_put(state->fb_damage_clips);
 385}
 386EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
 387
 388/**
 389 * drm_atomic_helper_plane_destroy_state - default state destroy hook
 390 * @plane: drm plane
 391 * @state: plane state object to release
 392 *
 393 * Default plane state destroy hook for drivers which don't have their own
 394 * subclassed plane state structure.
 395 */
 396void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
 397                                           struct drm_plane_state *state)
 398{
 399        __drm_atomic_helper_plane_destroy_state(state);
 400        kfree(state);
 401}
 402EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
 403
 404/**
 405 * __drm_atomic_helper_connector_state_reset - reset the connector state
 406 * @conn_state: atomic connector state, must not be NULL
 407 * @connector: connectotr object, must not be NULL
 408 *
 409 * Initializes the newly allocated @conn_state with default
 410 * values. This is useful for drivers that subclass the connector state.
 411 */
 412void
 413__drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
 414                                          struct drm_connector *connector)
 415{
 416        conn_state->connector = connector;
 417}
 418EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);
 419
 420/**
 421 * __drm_atomic_helper_connector_reset - reset state on connector
 422 * @connector: drm connector
 423 * @conn_state: connector state to assign
 424 *
 425 * Initializes the newly allocated @conn_state and assigns it to
 426 * the &drm_connector->state pointer of @connector, usually required when
 427 * initializing the drivers or when called from the &drm_connector_funcs.reset
 428 * hook.
 429 *
 430 * This is useful for drivers that subclass the connector state.
 431 */
 432void
 433__drm_atomic_helper_connector_reset(struct drm_connector *connector,
 434                                    struct drm_connector_state *conn_state)
 435{
 436        if (conn_state)
 437                __drm_atomic_helper_connector_state_reset(conn_state, connector);
 438
 439        connector->state = conn_state;
 440}
 441EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
 442
 443/**
 444 * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
 445 * @connector: drm connector
 446 *
 447 * Resets the atomic state for @connector by freeing the state pointer (which
 448 * might be NULL, e.g. at driver load time) and allocating a new empty state
 449 * object.
 450 */
 451void drm_atomic_helper_connector_reset(struct drm_connector *connector)
 452{
 453        struct drm_connector_state *conn_state =
 454                kzalloc(sizeof(*conn_state), GFP_KERNEL);
 455
 456        if (connector->state)
 457                __drm_atomic_helper_connector_destroy_state(connector->state);
 458
 459        kfree(connector->state);
 460        __drm_atomic_helper_connector_reset(connector, conn_state);
 461}
 462EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
 463
 464/**
 465 * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
 466 * @connector: DRM connector
 467 *
 468 * Resets the TV-related properties attached to a connector.
 469 */
 470void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
 471{
 472        struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
 473        struct drm_connector_state *state = connector->state;
 474
 475        state->tv.margins.left = cmdline->tv_margins.left;
 476        state->tv.margins.right = cmdline->tv_margins.right;
 477        state->tv.margins.top = cmdline->tv_margins.top;
 478        state->tv.margins.bottom = cmdline->tv_margins.bottom;
 479}
 480EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
 481
 482/**
 483 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
 484 * @connector: connector object
 485 * @state: atomic connector state
 486 *
 487 * Copies atomic state from a connector's current state. This is useful for
 488 * drivers that subclass the connector state.
 489 */
 490void
 491__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
 492                                            struct drm_connector_state *state)
 493{
 494        memcpy(state, connector->state, sizeof(*state));
 495        if (state->crtc)
 496                drm_connector_get(connector);
 497        state->commit = NULL;
 498
 499        if (state->hdr_output_metadata)
 500                drm_property_blob_get(state->hdr_output_metadata);
 501
 502        /* Don't copy over a writeback job, they are used only once */
 503        state->writeback_job = NULL;
 504}
 505EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
 506
 507/**
 508 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
 509 * @connector: drm connector
 510 *
 511 * Default connector state duplicate hook for drivers which don't have their own
 512 * subclassed connector state structure.
 513 */
 514struct drm_connector_state *
 515drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
 516{
 517        struct drm_connector_state *state;
 518
 519        if (WARN_ON(!connector->state))
 520                return NULL;
 521
 522        state = kmalloc(sizeof(*state), GFP_KERNEL);
 523        if (state)
 524                __drm_atomic_helper_connector_duplicate_state(connector, state);
 525
 526        return state;
 527}
 528EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
 529
 530/**
 531 * __drm_atomic_helper_connector_destroy_state - release connector state
 532 * @state: connector state object to release
 533 *
 534 * Releases all resources stored in the connector state without actually
 535 * freeing the memory of the connector state. This is useful for drivers that
 536 * subclass the connector state.
 537 */
 538void
 539__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
 540{
 541        if (state->crtc)
 542                drm_connector_put(state->connector);
 543
 544        if (state->commit)
 545                drm_crtc_commit_put(state->commit);
 546
 547        if (state->writeback_job)
 548                drm_writeback_cleanup_job(state->writeback_job);
 549
 550        drm_property_blob_put(state->hdr_output_metadata);
 551}
 552EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
 553
 554/**
 555 * drm_atomic_helper_connector_destroy_state - default state destroy hook
 556 * @connector: drm connector
 557 * @state: connector state object to release
 558 *
 559 * Default connector state destroy hook for drivers which don't have their own
 560 * subclassed connector state structure.
 561 */
 562void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
 563                                          struct drm_connector_state *state)
 564{
 565        __drm_atomic_helper_connector_destroy_state(state);
 566        kfree(state);
 567}
 568EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
 569
 570/**
 571 * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
 572 * @obj: CRTC object
 573 * @state: new private object state
 574 *
 575 * Copies atomic state from a private objects's current state and resets inferred values.
 576 * This is useful for drivers that subclass the private state.
 577 */
 578void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
 579                                                     struct drm_private_state *state)
 580{
 581        memcpy(state, obj->state, sizeof(*state));
 582}
 583EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
 584
 585/**
 586 * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
 587 * @bridge: bridge object
 588 * @state: atomic bridge state
 589 *
 590 * Copies atomic state from a bridge's current state and resets inferred values.
 591 * This is useful for drivers that subclass the bridge state.
 592 */
 593void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
 594                                                struct drm_bridge_state *state)
 595{
 596        __drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
 597                                                        &state->base);
 598        state->bridge = bridge;
 599}
 600EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
 601
 602/**
 603 * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
 604 * @bridge: bridge object
 605 *
 606 * Allocates a new bridge state and initializes it with the current bridge
 607 * state values. This helper is meant to be used as a bridge
 608 * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
 609 * subclass the bridge state.
 610 */
 611struct drm_bridge_state *
 612drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
 613{
 614        struct drm_bridge_state *new;
 615
 616        if (WARN_ON(!bridge->base.state))
 617                return NULL;
 618
 619        new = kzalloc(sizeof(*new), GFP_KERNEL);
 620        if (new)
 621                __drm_atomic_helper_bridge_duplicate_state(bridge, new);
 622
 623        return new;
 624}
 625EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
 626
 627/**
 628 * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
 629 * @bridge: the bridge this state refers to
 630 * @state: bridge state to destroy
 631 *
 632 * Destroys a bridge state previously created by
 633 * &drm_atomic_helper_bridge_reset() or
 634 * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
 635 * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
 636 * that don't subclass the bridge state.
 637 */
 638void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
 639                                            struct drm_bridge_state *state)
 640{
 641        kfree(state);
 642}
 643EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
 644
 645/**
 646 * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
 647 *                                      default
 648 * @bridge: the bridge this state refers to
 649 * @state: bridge state to initialize
 650 *
 651 * Initializes the bridge state to default values. This is meant to be called
 652 * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
 653 * the bridge state.
 654 */
 655void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
 656                                      struct drm_bridge_state *state)
 657{
 658        memset(state, 0, sizeof(*state));
 659        state->bridge = bridge;
 660}
 661EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
 662
 663/**
 664 * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
 665 *                                    to its default
 666 * @bridge: the bridge this state refers to
 667 *
 668 * Allocates the bridge state and initializes it to default values. This helper
 669 * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
 670 * bridges that don't subclass the bridge state.
 671 */
 672struct drm_bridge_state *
 673drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
 674{
 675        struct drm_bridge_state *bridge_state;
 676
 677        bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
 678        if (!bridge_state)
 679                return ERR_PTR(-ENOMEM);
 680
 681        __drm_atomic_helper_bridge_reset(bridge, bridge_state);
 682        return bridge_state;
 683}
 684EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);
 685