drivers/gpu/drm/drm_crtc_helper.c

   1 /*
   2  * Copyright (c) 2006-2008 Intel Corporation
   3  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   4  *
   5  * DRM core CRTC related functions
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and its
   8  * documentation for any purpose is hereby granted without fee, provided that
   9  * the above copyright notice appear in all copies and that both that copyright
  10  * notice and this permission notice appear in supporting documentation, and
  11  * that the name of the copyright holders not be used in advertising or
  12  * publicity pertaining to distribution of the software without specific,
  13  * written prior permission.  The copyright holders make no representations
  14  * about the suitability of this software for any purpose.  It is provided "as
  15  * is" without express or implied warranty.
  16  *
  17  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  19  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  20  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  22  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  23  * OF THIS SOFTWARE.
  24  *
  25  * Authors:
  26  *      Keith Packard
  27  *      Eric Anholt <eric@anholt.net>
  28  *      Dave Airlie <airlied@linux.ie>
  29  *      Jesse Barnes <jesse.barnes@intel.com>
  30  */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/export.h>
  34 #include <linux/moduleparam.h>
  35
  36 #include <drm/drmP.h>
  37 #include <drm/drm_crtc.h>
  38 #include <drm/drm_fourcc.h>
  39 #include <drm/drm_crtc_helper.h>
  40 #include <drm/drm_fb_helper.h>
  41 #include <drm/drm_edid.h>
  42
  43 MODULE_AUTHOR("David Airlie, Jesse Barnes");
  44 MODULE_DESCRIPTION("DRM KMS helper");
  45 MODULE_LICENSE("GPL and additional rights");
  46
  47 /**
  48  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
  49  *                                              connector list
  50  * @dev: drm device to operate on
  51  *
  52  * Some userspace presumes that the first connected connector is the main
  53  * display, where it's supposed to display e.g. the login screen. For
  54  * laptops, this should be the main panel. Use this function to sort all
  55  * (eDP/LVDS) panels to the front of the connector list, instead of
  56  * painstakingly trying to initialize them in the right order.
  57  */
  58 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
  59 {
  60         struct drm_connector *connector, *tmp;
  61         struct list_head panel_list;
  62
  63         INIT_LIST_HEAD(&panel_list);
  64
  65         list_for_each_entry_safe(connector, tmp,
  66                                  &dev->mode_config.connector_list, head) {
  67                 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
  68                     connector->connector_type == DRM_MODE_CONNECTOR_eDP)
  69                         list_move_tail(&connector->head, &panel_list);
  70         }
  71
  72         list_splice(&panel_list, &dev->mode_config.connector_list);
  73 }
  74 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
  75
  76 /**
  77  * drm_helper_encoder_in_use - check if a given encoder is in use
  78  * @encoder: encoder to check
  79  *
  80  * Checks whether @encoder is with the current mode setting output configuration
  81  * in use by any connector. This doesn't mean that it is actually enabled since
  82  * the DPMS state is tracked separately.
  83  *
  84  * Returns:
  85  * True if @encoder is used, false otherwise.
  86  */
  87 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
  88 {
  89         struct drm_connector *connector;
  90         struct drm_device *dev = encoder->dev;
  91
  92         /*
  93          * We can expect this mutex to be locked if we are not panicking.
  94          * Locking is currently fubar in the panic handler.
  95          */
  96         if (!oops_in_progress)
  97                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
  98
  99         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 100                 if (connector->encoder == encoder)
 101                         return true;
 102         return false;
 103 }
 104 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 105
 106 /**
 107  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 108  * @crtc: CRTC to check
 109  *
 110  * Checks whether @crtc is with the current mode setting output configuration
 111  * in use by any connector. This doesn't mean that it is actually enabled since
 112  * the DPMS state is tracked separately.
 113  *
 114  * Returns:
 115  * True if @crtc is used, false otherwise.
 116  */
 117 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 118 {
 119         struct drm_encoder *encoder;
 120         struct drm_device *dev = crtc->dev;
 121
 122         /*
 123          * We can expect this mutex to be locked if we are not panicking.
 124          * Locking is currently fubar in the panic handler.
 125          */
 126         if (!oops_in_progress)
 127                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 128
 129         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
 130                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 131                         return true;
 132         return false;
 133 }
 134 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 135
 136 static void
 137 drm_encoder_disable(struct drm_encoder *encoder)
 138 {
 139         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 140
 141         if (encoder->bridge)
 142                 encoder->bridge->funcs->disable(encoder->bridge);
 143
 144         if (encoder_funcs->disable)
 145                 (*encoder_funcs->disable)(encoder);
 146         else
 147                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 148
 149         if (encoder->bridge)
 150                 encoder->bridge->funcs->post_disable(encoder->bridge);
 151 }
 152
 153 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 154 {
 155         struct drm_encoder *encoder;
 156         struct drm_connector *connector;
 157         struct drm_crtc *crtc;
 158
 159         drm_warn_on_modeset_not_all_locked(dev);
 160
 161         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 162                 if (!connector->encoder)
 163                         continue;
 164         }
 165
 166         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 167                 if (!drm_helper_encoder_in_use(encoder)) {
 168                         drm_encoder_disable(encoder);
 169                         /* disconnector encoder from any connector */
 170                         encoder->crtc = NULL;
 171                 }
 172         }
 173
 174         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 175                 struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 176                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 177                 if (!crtc->enabled) {
 178                         if (crtc_funcs->disable)
 179                                 (*crtc_funcs->disable)(crtc);
 180                         else
 181                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 182                         crtc->primary->fb = NULL;
 183                 }
 184         }
 185 }
 186
 187 /**
 188  * drm_helper_disable_unused_functions - disable unused objects
 189  * @dev: DRM device
 190  *
 191  * This function walks through the entire mode setting configuration of @dev. It
 192  * will remove any crtc links of unused encoders and encoder links of
 193  * disconnected connectors. Then it will disable all unused encoders and crtcs
 194  * either by calling their disable callback if available or by calling their
 195  * dpms callback with DRM_MODE_DPMS_OFF.
 196  */
 197 void drm_helper_disable_unused_functions(struct drm_device *dev)
 198 {
 199         drm_modeset_lock_all(dev);
 200         __drm_helper_disable_unused_functions(dev);
 201         drm_modeset_unlock_all(dev);
 202 }
 203 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 204
 205 /*
 206  * Check the CRTC we're going to map each output to vs. its current
 207  * CRTC.  If they don't match, we have to disable the output and the CRTC
 208  * since the driver will have to re-route things.
 209  */
 210 static void
 211 drm_crtc_prepare_encoders(struct drm_device *dev)
 212 {
 213         struct drm_encoder_helper_funcs *encoder_funcs;
 214         struct drm_encoder *encoder;
 215
 216         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 217                 encoder_funcs = encoder->helper_private;
 218                 /* Disable unused encoders */
 219                 if (encoder->crtc == NULL)
 220                         drm_encoder_disable(encoder);
 221                 /* Disable encoders whose CRTC is about to change */
 222                 if (encoder_funcs->get_crtc &&
 223                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 224                         drm_encoder_disable(encoder);
 225         }
 226 }
 227
 228 /**
 229  * drm_crtc_helper_set_mode - internal helper to set a mode
 230  * @crtc: CRTC to program
 231  * @mode: mode to use
 232  * @x: horizontal offset into the surface
 233  * @y: vertical offset into the surface
 234  * @old_fb: old framebuffer, for cleanup
 235  *
 236  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 237  * to fixup or reject the mode prior to trying to set it. This is an internal
 238  * helper that drivers could e.g. use to update properties that require the
 239  * entire output pipe to be disabled and re-enabled in a new configuration. For
 240  * example for changing whether audio is enabled on a hdmi link or for changing
 241  * panel fitter or dither attributes. It is also called by the
 242  * drm_crtc_helper_set_config() helper function to drive the mode setting
 243  * sequence.
 244  *
 245  * Returns:
 246  * True if the mode was set successfully, false otherwise.
 247  */
 248 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 249                               struct drm_display_mode *mode,
 250                               int x, int y,
 251                               struct drm_framebuffer *old_fb)
 252 {
 253         struct drm_device *dev = crtc->dev;
 254         struct drm_display_mode *adjusted_mode, saved_mode;
 255         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 256         struct drm_encoder_helper_funcs *encoder_funcs;
 257         int saved_x, saved_y;
 258         bool saved_enabled;
 259         struct drm_encoder *encoder;
 260         bool ret = true;
 261
 262         drm_warn_on_modeset_not_all_locked(dev);
 263
 264         saved_enabled = crtc->enabled;
 265         crtc->enabled = drm_helper_crtc_in_use(crtc);
 266         if (!crtc->enabled)
 267                 return true;
 268
 269         adjusted_mode = drm_mode_duplicate(dev, mode);
 270         if (!adjusted_mode) {
 271                 crtc->enabled = saved_enabled;
 272                 return false;
 273         }
 274
 275         saved_mode = crtc->mode;
 276         saved_x = crtc->x;
 277         saved_y = crtc->y;
 278
 279         /* Update crtc values up front so the driver can rely on them for mode
 280          * setting.
 281          */
 282         crtc->mode = *mode;
 283         crtc->x = x;
 284         crtc->y = y;
 285
 286         /* Pass our mode to the connectors and the CRTC to give them a chance to
 287          * adjust it according to limitations or connector properties, and also
 288          * a chance to reject the mode entirely.
 289          */
 290         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 291
 292                 if (encoder->crtc != crtc)
 293                         continue;
 294
 295                 if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
 296                         ret = encoder->bridge->funcs->mode_fixup(
 297                                         encoder->bridge, mode, adjusted_mode);
 298                         if (!ret) {
 299                                 DRM_DEBUG_KMS("Bridge fixup failed\n");
 300                                 goto done;
 301                         }
 302                 }
 303
 304                 encoder_funcs = encoder->helper_private;
 305                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 306                                                       adjusted_mode))) {
 307                         DRM_DEBUG_KMS("Encoder fixup failed\n");
 308                         goto done;
 309                 }
 310         }
 311
 312         if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
 313                 DRM_DEBUG_KMS("CRTC fixup failed\n");
 314                 goto done;
 315         }
 316         DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);
 317
 318         /* Prepare the encoders and CRTCs before setting the mode. */
 319         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 320
 321                 if (encoder->crtc != crtc)
 322                         continue;
 323
 324                 if (encoder->bridge)
 325                         encoder->bridge->funcs->disable(encoder->bridge);
 326
 327                 encoder_funcs = encoder->helper_private;
 328                 /* Disable the encoders as the first thing we do. */
 329                 encoder_funcs->prepare(encoder);
 330
 331                 if (encoder->bridge)
 332                         encoder->bridge->funcs->post_disable(encoder->bridge);
 333         }
 334
 335         drm_crtc_prepare_encoders(dev);
 336
 337         crtc_funcs->prepare(crtc);
 338
 339         /* Set up the DPLL and any encoders state that needs to adjust or depend
 340          * on the DPLL.
 341          */
 342         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 343         if (!ret)
 344             goto done;
 345
 346         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 347
 348                 if (encoder->crtc != crtc)
 349                         continue;
 350
 351                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
 352                         encoder->base.id, drm_get_encoder_name(encoder),
 353                         mode->base.id, mode->name);
 354                 encoder_funcs = encoder->helper_private;
 355                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 356
 357                 if (encoder->bridge && encoder->bridge->funcs->mode_set)
 358                         encoder->bridge->funcs->mode_set(encoder->bridge, mode,
 359                                         adjusted_mode);
 360         }
 361
 362         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 363         crtc_funcs->commit(crtc);
 364
 365         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 366
 367                 if (encoder->crtc != crtc)
 368                         continue;
 369
 370                 if (encoder->bridge)
 371                         encoder->bridge->funcs->pre_enable(encoder->bridge);
 372
 373                 encoder_funcs = encoder->helper_private;
 374                 encoder_funcs->commit(encoder);
 375
 376                 if (encoder->bridge)
 377                         encoder->bridge->funcs->enable(encoder->bridge);
 378         }
 379
 380         /* Store real post-adjustment hardware mode. */
 381         crtc->hwmode = *adjusted_mode;
 382
 383         /* Calculate and store various constants which
 384          * are later needed by vblank and swap-completion
 385          * timestamping. They are derived from true hwmode.
 386          */
 387         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 388
 389         /* FIXME: add subpixel order */
 390 done:
 391         drm_mode_destroy(dev, adjusted_mode);
 392         if (!ret) {
 393                 crtc->enabled = saved_enabled;
 394                 crtc->mode = saved_mode;
 395                 crtc->x = saved_x;
 396                 crtc->y = saved_y;
 397         }
 398
 399         return ret;
 400 }
 401 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 402
 403
 404 static int
 405 drm_crtc_helper_disable(struct drm_crtc *crtc)
 406 {
 407         struct drm_device *dev = crtc->dev;
 408         struct drm_connector *connector;
 409         struct drm_encoder *encoder;
 410
 411         /* Decouple all encoders and their attached connectors from this crtc */
 412         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 413                 if (encoder->crtc != crtc)
 414                         continue;
 415
 416                 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 417                         if (connector->encoder != encoder)
 418                                 continue;
 419
 420                         connector->encoder = NULL;
 421
 422                         /*
 423                          * drm_helper_disable_unused_functions() ought to be
 424                          * doing this, but since we've decoupled the encoder
 425                          * from the connector above, the required connection
 426                          * between them is henceforth no longer available.
 427                          */
 428                         connector->dpms = DRM_MODE_DPMS_OFF;
 429                 }
 430         }
 431
 432         __drm_helper_disable_unused_functions(dev);
 433         return 0;
 434 }
 435
 436 /**
 437  * drm_crtc_helper_set_config - set a new config from userspace
 438  * @set: mode set configuration
 439  *
 440  * Setup a new configuration, provided by the upper layers (either an ioctl call
 441  * from userspace or internally e.g. from the fbdev support code) in @set, and
 442  * enable it. This is the main helper functions for drivers that implement
 443  * kernel mode setting with the crtc helper functions and the assorted
 444  * ->prepare(), ->modeset() and ->commit() helper callbacks.
 445  *
 446  * Returns:
 447  * Returns 0 on success, negative errno numbers on failure.
 448  */
 449 int drm_crtc_helper_set_config(struct drm_mode_set *set)
 450 {
 451         struct drm_device *dev;
 452         struct drm_crtc *new_crtc;
 453         struct drm_encoder *save_encoders, *new_encoder, *encoder;
 454         bool mode_changed = false; /* if true do a full mode set */
 455         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 456         struct drm_connector *save_connectors, *connector;
 457         int count = 0, ro, fail = 0;
 458         struct drm_crtc_helper_funcs *crtc_funcs;
 459         struct drm_mode_set save_set;
 460         int ret;
 461         int i;
 462
 463         DRM_DEBUG_KMS("\n");
 464
 465         BUG_ON(!set);
 466         BUG_ON(!set->crtc);
 467         BUG_ON(!set->crtc->helper_private);
 468
 469         /* Enforce sane interface api - has been abused by the fb helper. */
 470         BUG_ON(!set->mode && set->fb);
 471         BUG_ON(set->fb && set->num_connectors == 0);
 472
 473         crtc_funcs = set->crtc->helper_private;
 474
 475         if (!set->mode)
 476                 set->fb = NULL;
 477
 478         if (set->fb) {
 479                 DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 480                                 set->crtc->base.id, set->fb->base.id,
 481                                 (int)set->num_connectors, set->x, set->y);
 482         } else {
 483                 DRM_DEBUG_KMS("[CRTC:%d] [NOFB]\n", set->crtc->base.id);
 484                 return drm_crtc_helper_disable(set->crtc);
 485         }
 486
 487         dev = set->crtc->dev;
 488
 489         drm_warn_on_modeset_not_all_locked(dev);
 490
 491         /*
 492          * Allocate space for the backup of all (non-pointer) encoder and
 493          * connector data.
 494          */
 495         save_encoders = kzalloc(dev->mode_config.num_encoder *
 496                                 sizeof(struct drm_encoder), GFP_KERNEL);
 497         if (!save_encoders)
 498                 return -ENOMEM;
 499
 500         save_connectors = kzalloc(dev->mode_config.num_connector *
 501                                 sizeof(struct drm_connector), GFP_KERNEL);
 502         if (!save_connectors) {
 503                 kfree(save_encoders);
 504                 return -ENOMEM;
 505         }
 506
 507         /*
 508          * Copy data. Note that driver private data is not affected.
 509          * Should anything bad happen only the expected state is
 510          * restored, not the drivers personal bookkeeping.
 511          */
 512         count = 0;
 513         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 514                 save_encoders[count++] = *encoder;
 515         }
 516
 517         count = 0;
 518         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 519                 save_connectors[count++] = *connector;
 520         }
 521
 522         save_set.crtc = set->crtc;
 523         save_set.mode = &set->crtc->mode;
 524         save_set.x = set->crtc->x;
 525         save_set.y = set->crtc->y;
 526         save_set.fb = set->crtc->primary->fb;
 527
 528         /* We should be able to check here if the fb has the same properties
 529          * and then just flip_or_move it */
 530         if (set->crtc->primary->fb != set->fb) {
 531                 /* If we have no fb then treat it as a full mode set */
 532                 if (set->crtc->primary->fb == NULL) {
 533                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 534                         mode_changed = true;
 535                 } else if (set->fb == NULL) {
 536                         mode_changed = true;
 537                 } else if (set->fb->pixel_format !=
 538                            set->crtc->primary->fb->pixel_format) {
 539                         mode_changed = true;
 540                 } else
 541                         fb_changed = true;
 542         }
 543
 544         if (set->x != set->crtc->x || set->y != set->crtc->y)
 545                 fb_changed = true;
 546
 547         if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
 548                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 549                 drm_mode_debug_printmodeline(&set->crtc->mode);
 550                 drm_mode_debug_printmodeline(set->mode);
 551                 mode_changed = true;
 552         }
 553
 554         /* a) traverse passed in connector list and get encoders for them */
 555         count = 0;
 556         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 557                 struct drm_connector_helper_funcs *connector_funcs =
 558                         connector->helper_private;
 559                 new_encoder = connector->encoder;
 560                 for (ro = 0; ro < set->num_connectors; ro++) {
 561                         if (set->connectors[ro] == connector) {
 562                                 new_encoder = connector_funcs->best_encoder(connector);
 563                                 /* if we can't get an encoder for a connector
 564                                    we are setting now - then fail */
 565                                 if (new_encoder == NULL)
 566                                         /* don't break so fail path works correct */
 567                                         fail = 1;
 568
 569                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 570                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 571                                         mode_changed = true;
 572                                 }
 573
 574                                 break;
 575                         }
 576                 }
 577
 578                 if (new_encoder != connector->encoder) {
 579                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 580                         mode_changed = true;
 581                         /* If the encoder is reused for another connector, then
 582                          * the appropriate crtc will be set later.
 583                          */
 584                         if (connector->encoder)
 585                                 connector->encoder->crtc = NULL;
 586                         connector->encoder = new_encoder;
 587                 }
 588         }
 589
 590         if (fail) {
 591                 ret = -EINVAL;
 592                 goto fail;
 593         }
 594
 595         count = 0;
 596         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 597                 if (!connector->encoder)
 598                         continue;
 599
 600                 if (connector->encoder->crtc == set->crtc)
 601                         new_crtc = NULL;
 602                 else
 603                         new_crtc = connector->encoder->crtc;
 604
 605                 for (ro = 0; ro < set->num_connectors; ro++) {
 606                         if (set->connectors[ro] == connector)
 607                                 new_crtc = set->crtc;
 608                 }
 609
 610                 /* Make sure the new CRTC will work with the encoder */
 611                 if (new_crtc &&
 612                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 613                         ret = -EINVAL;
 614                         goto fail;
 615                 }
 616                 if (new_crtc != connector->encoder->crtc) {
 617                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 618                         mode_changed = true;
 619                         connector->encoder->crtc = new_crtc;
 620                 }
 621                 if (new_crtc) {
 622                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 623                                 connector->base.id, drm_get_connector_name(connector),
 624                                 new_crtc->base.id);
 625                 } else {
 626                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 627                                 connector->base.id, drm_get_connector_name(connector));
 628                 }
 629         }
 630
 631         /* mode_set_base is not a required function */
 632         if (fb_changed && !crtc_funcs->mode_set_base)
 633                 mode_changed = true;
 634
 635         if (mode_changed) {
 636                 if (drm_helper_crtc_in_use(set->crtc)) {
 637                         DRM_DEBUG_KMS("attempting to set mode from"
 638                                         " userspace\n");
 639                         drm_mode_debug_printmodeline(set->mode);
 640                         set->crtc->primary->fb = set->fb;
 641                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 642                                                       set->x, set->y,
 643                                                       save_set.fb)) {
 644                                 DRM_ERROR("failed to set mode on [CRTC:%d]\n",
 645                                           set->crtc->base.id);
 646                                 set->crtc->primary->fb = save_set.fb;
 647                                 ret = -EINVAL;
 648                                 goto fail;
 649                         }
 650                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 651                         for (i = 0; i < set->num_connectors; i++) {
 652                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 653                                               drm_get_connector_name(set->connectors[i]));
 654                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 655                         }
 656                 }
 657                 __drm_helper_disable_unused_functions(dev);
 658         } else if (fb_changed) {
 659                 set->crtc->x = set->x;
 660                 set->crtc->y = set->y;
 661                 set->crtc->primary->fb = set->fb;
 662                 ret = crtc_funcs->mode_set_base(set->crtc,
 663                                                 set->x, set->y, save_set.fb);
 664                 if (ret != 0) {
 665                         set->crtc->x = save_set.x;
 666                         set->crtc->y = save_set.y;
 667                         set->crtc->primary->fb = save_set.fb;
 668                         goto fail;
 669                 }
 670         }
 671
 672         kfree(save_connectors);
 673         kfree(save_encoders);
 674         return 0;
 675
 676 fail:
 677         /* Restore all previous data. */
 678         count = 0;
 679         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 680                 *encoder = save_encoders[count++];
 681         }
 682
 683         count = 0;
 684         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 685                 *connector = save_connectors[count++];
 686         }
 687
 688         /* Try to restore the config */
 689         if (mode_changed &&
 690             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 691                                       save_set.y, save_set.fb))
 692                 DRM_ERROR("failed to restore config after modeset failure\n");
 693
 694         kfree(save_connectors);
 695         kfree(save_encoders);
 696         return ret;
 697 }
 698 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 699
 700 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 701 {
 702         int dpms = DRM_MODE_DPMS_OFF;
 703         struct drm_connector *connector;
 704         struct drm_device *dev = encoder->dev;
 705
 706         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 707                 if (connector->encoder == encoder)
 708                         if (connector->dpms < dpms)
 709                                 dpms = connector->dpms;
 710         return dpms;
 711 }
 712
 713 /* Helper which handles bridge ordering around encoder dpms */
 714 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 715 {
 716         struct drm_bridge *bridge = encoder->bridge;
 717         struct drm_encoder_helper_funcs *encoder_funcs;
 718
 719         if (bridge) {
 720                 if (mode == DRM_MODE_DPMS_ON)
 721                         bridge->funcs->pre_enable(bridge);
 722                 else
 723                         bridge->funcs->disable(bridge);
 724         }
 725
 726         encoder_funcs = encoder->helper_private;
 727         if (encoder_funcs->dpms)
 728                 encoder_funcs->dpms(encoder, mode);
 729
 730         if (bridge) {
 731                 if (mode == DRM_MODE_DPMS_ON)
 732                         bridge->funcs->enable(bridge);
 733                 else
 734                         bridge->funcs->post_disable(bridge);
 735         }
 736 }
 737
 738 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 739 {
 740         int dpms = DRM_MODE_DPMS_OFF;
 741         struct drm_connector *connector;
 742         struct drm_device *dev = crtc->dev;
 743
 744         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 745                 if (connector->encoder && connector->encoder->crtc == crtc)
 746                         if (connector->dpms < dpms)
 747                                 dpms = connector->dpms;
 748         return dpms;
 749 }
 750
 751 /**
 752  * drm_helper_connector_dpms() - connector dpms helper implementation
 753  * @connector: affected connector
 754  * @mode: DPMS mode
 755  *
 756  * This is the main helper function provided by the crtc helper framework for
 757  * implementing the DPMS connector attribute. It computes the new desired DPMS
 758  * state for all encoders and crtcs in the output mesh and calls the ->dpms()
 759  * callback provided by the driver appropriately.
 760  */
 761 void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 762 {
 763         struct drm_encoder *encoder = connector->encoder;
 764         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 765         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 766
 767         if (mode == connector->dpms)
 768                 return;
 769
 770         old_dpms = connector->dpms;
 771         connector->dpms = mode;
 772
 773         if (encoder)
 774                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 775
 776         /* from off to on, do crtc then encoder */
 777         if (mode < old_dpms) {
 778                 if (crtc) {
 779                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 780                         if (crtc_funcs->dpms)
 781                                 (*crtc_funcs->dpms) (crtc,
 782                                                      drm_helper_choose_crtc_dpms(crtc));
 783                 }
 784                 if (encoder)
 785                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 786         }
 787
 788         /* from on to off, do encoder then crtc */
 789         if (mode > old_dpms) {
 790                 if (encoder)
 791                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 792                 if (crtc) {
 793                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 794                         if (crtc_funcs->dpms)
 795                                 (*crtc_funcs->dpms) (crtc,
 796                                                      drm_helper_choose_crtc_dpms(crtc));
 797                 }
 798         }
 799
 800         return;
 801 }
 802 EXPORT_SYMBOL(drm_helper_connector_dpms);
 803
 804 /**
 805  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
 806  * @fb: drm_framebuffer object to fill out
 807  * @mode_cmd: metadata from the userspace fb creation request
 808  *
 809  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
 810  * metadata fields.
 811  */
 812 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
 813                                     struct drm_mode_fb_cmd2 *mode_cmd)
 814 {
 815         int i;
 816
 817         fb->width = mode_cmd->width;
 818         fb->height = mode_cmd->height;
 819         for (i = 0; i < 4; i++) {
 820                 fb->pitches[i] = mode_cmd->pitches[i];
 821                 fb->offsets[i] = mode_cmd->offsets[i];
 822         }
 823         drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
 824                                     &fb->bits_per_pixel);
 825         fb->pixel_format = mode_cmd->pixel_format;
 826 }
 827 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
 828
 829 /**
 830  * drm_helper_resume_force_mode - force-restore mode setting configuration
 831  * @dev: drm_device which should be restored
 832  *
 833  * Drivers which use the mode setting helpers can use this function to
 834  * force-restore the mode setting configuration e.g. on resume or when something
 835  * else might have trampled over the hw state (like some overzealous old BIOSen
 836  * tended to do).
 837  *
 838  * This helper doesn't provide a error return value since restoring the old
 839  * config should never fail due to resource allocation issues since the driver
 840  * has successfully set the restored configuration already. Hence this should
 841  * boil down to the equivalent of a few dpms on calls, which also don't provide
 842  * an error code.
 843  *
 844  * Drivers where simply restoring an old configuration again might fail (e.g.
 845  * due to slight differences in allocating shared resources when the
 846  * configuration is restored in a different order than when userspace set it up)
 847  * need to use their own restore logic.
 848  */
 849 void drm_helper_resume_force_mode(struct drm_device *dev)
 850 {
 851         struct drm_crtc *crtc;
 852         struct drm_encoder *encoder;
 853         struct drm_crtc_helper_funcs *crtc_funcs;
 854         int encoder_dpms;
 855         bool ret;
 856
 857         drm_modeset_lock_all(dev);
 858         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 859
 860                 if (!crtc->enabled)
 861                         continue;
 862
 863                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 864                                                crtc->x, crtc->y, crtc->primary->fb);
 865
 866                 /* Restoring the old config should never fail! */
 867                 if (ret == false)
 868                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 869
 870                 /* Turn off outputs that were already powered off */
 871                 if (drm_helper_choose_crtc_dpms(crtc)) {
 872                         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 873
 874                                 if(encoder->crtc != crtc)
 875                                         continue;
 876
 877                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 878                                                         encoder);
 879
 880                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 881                         }
 882
 883                         crtc_funcs = crtc->helper_private;
 884                         if (crtc_funcs->dpms)
 885                                 (*crtc_funcs->dpms) (crtc,
 886                                                      drm_helper_choose_crtc_dpms(crtc));
 887                 }
 888         }
 889
 890         /* disable the unused connectors while restoring the modesetting */
 891         __drm_helper_disable_unused_functions(dev);
 892         drm_modeset_unlock_all(dev);
 893 }
 894 EXPORT_SYMBOL(drm_helper_resume_force_mode);