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/export.h>
  33 #include <linux/moduleparam.h>
  34
  35 #include <drm/drmP.h>
  36 #include <drm/drm_crtc.h>
  37 #include <drm/drm_fourcc.h>
  38 #include <drm/drm_crtc_helper.h>
  39 #include <drm/drm_fb_helper.h>
  40 #include <drm/drm_edid.h>
  41
  42 /**
  43  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
  44  *                                              connector list
  45  * @dev: drm device to operate on
  46  *
  47  * Some userspace presumes that the first connected connector is the main
  48  * display, where it's supposed to display e.g. the login screen. For
  49  * laptops, this should be the main panel. Use this function to sort all
  50  * (eDP/LVDS) panels to the front of the connector list, instead of
  51  * painstakingly trying to initialize them in the right order.
  52  */
  53 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
  54 {
  55         struct drm_connector *connector, *tmp;
  56         struct list_head panel_list;
  57
  58         INIT_LIST_HEAD(&panel_list);
  59
  60         list_for_each_entry_safe(connector, tmp,
  61                                  &dev->mode_config.connector_list, head) {
  62                 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
  63                     connector->connector_type == DRM_MODE_CONNECTOR_eDP)
  64                         list_move_tail(&connector->head, &panel_list);
  65         }
  66
  67         list_splice(&panel_list, &dev->mode_config.connector_list);
  68 }
  69 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
  70
  71 static bool drm_kms_helper_poll = true;
  72 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
  73
  74 static void drm_mode_validate_flag(struct drm_connector *connector,
  75                                    int flags)
  76 {
  77         struct drm_display_mode *mode;
  78
  79         if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE))
  80                 return;
  81
  82         list_for_each_entry(mode, &connector->modes, head) {
  83                 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
  84                                 !(flags & DRM_MODE_FLAG_INTERLACE))
  85                         mode->status = MODE_NO_INTERLACE;
  86                 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
  87                                 !(flags & DRM_MODE_FLAG_DBLSCAN))
  88                         mode->status = MODE_NO_DBLESCAN;
  89         }
  90
  91         return;
  92 }
  93
  94 /**
  95  * drm_helper_probe_single_connector_modes - get complete set of display modes
  96  * @connector: connector to probe
  97  * @maxX: max width for modes
  98  * @maxY: max height for modes
  99  *
 100  * LOCKING:
 101  * Caller must hold mode config lock.
 102  *
 103  * Based on the helper callbacks implemented by @connector try to detect all
 104  * valid modes.  Modes will first be added to the connector's probed_modes list,
 105  * then culled (based on validity and the @maxX, @maxY parameters) and put into
 106  * the normal modes list.
 107  *
 108  * Intended to be use as a generic implementation of the ->probe() @connector
 109  * callback for drivers that use the crtc helpers for output mode filtering and
 110  * detection.
 111  *
 112  * RETURNS:
 113  * Number of modes found on @connector.
 114  */
 115 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 116                                             uint32_t maxX, uint32_t maxY)
 117 {
 118         struct drm_device *dev = connector->dev;
 119         struct drm_display_mode *mode;
 120         struct drm_connector_helper_funcs *connector_funcs =
 121                 connector->helper_private;
 122         int count = 0;
 123         int mode_flags = 0;
 124         bool verbose_prune = true;
 125
 126         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
 127                         drm_get_connector_name(connector));
 128         /* set all modes to the unverified state */
 129         list_for_each_entry(mode, &connector->modes, head)
 130                 mode->status = MODE_UNVERIFIED;
 131
 132         if (connector->force) {
 133                 if (connector->force == DRM_FORCE_ON)
 134                         connector->status = connector_status_connected;
 135                 else
 136                         connector->status = connector_status_disconnected;
 137                 if (connector->funcs->force)
 138                         connector->funcs->force(connector);
 139         } else {
 140                 connector->status = connector->funcs->detect(connector, true);
 141         }
 142
 143         /* Re-enable polling in case the global poll config changed. */
 144         if (drm_kms_helper_poll != dev->mode_config.poll_running)
 145                 drm_kms_helper_poll_enable(dev);
 146
 147         dev->mode_config.poll_running = drm_kms_helper_poll;
 148
 149         if (connector->status == connector_status_disconnected) {
 150                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
 151                         connector->base.id, drm_get_connector_name(connector));
 152                 drm_mode_connector_update_edid_property(connector, NULL);
 153                 verbose_prune = false;
 154                 goto prune;
 155         }
 156
 157 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
 158         count = drm_load_edid_firmware(connector);
 159         if (count == 0)
 160 #endif
 161                 count = (*connector_funcs->get_modes)(connector);
 162
 163         if (count == 0 && connector->status == connector_status_connected)
 164                 count = drm_add_modes_noedid(connector, 1024, 768);
 165         if (count == 0)
 166                 goto prune;
 167
 168         drm_mode_connector_list_update(connector);
 169
 170         if (maxX && maxY)
 171                 drm_mode_validate_size(dev, &connector->modes, maxX,
 172                                        maxY, 0);
 173
 174         if (connector->interlace_allowed)
 175                 mode_flags |= DRM_MODE_FLAG_INTERLACE;
 176         if (connector->doublescan_allowed)
 177                 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
 178         drm_mode_validate_flag(connector, mode_flags);
 179
 180         list_for_each_entry(mode, &connector->modes, head) {
 181                 if (mode->status == MODE_OK)
 182                         mode->status = connector_funcs->mode_valid(connector,
 183                                                                    mode);
 184         }
 185
 186 prune:
 187         drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
 188
 189         if (list_empty(&connector->modes))
 190                 return 0;
 191
 192         drm_mode_sort(&connector->modes);
 193
 194         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
 195                         drm_get_connector_name(connector));
 196         list_for_each_entry(mode, &connector->modes, head) {
 197                 mode->vrefresh = drm_mode_vrefresh(mode);
 198
 199                 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 200                 drm_mode_debug_printmodeline(mode);
 201         }
 202
 203         return count;
 204 }
 205 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
 206
 207 /**
 208  * drm_helper_encoder_in_use - check if a given encoder is in use
 209  * @encoder: encoder to check
 210  *
 211  * LOCKING:
 212  * Caller must hold mode config lock.
 213  *
 214  * Walk @encoders's DRM device's mode_config and see if it's in use.
 215  *
 216  * RETURNS:
 217  * True if @encoder is part of the mode_config, false otherwise.
 218  */
 219 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
 220 {
 221         struct drm_connector *connector;
 222         struct drm_device *dev = encoder->dev;
 223         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 224                 if (connector->encoder == encoder)
 225                         return true;
 226         return false;
 227 }
 228 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 229
 230 /**
 231  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 232  * @crtc: CRTC to check
 233  *
 234  * LOCKING:
 235  * Caller must hold mode config lock.
 236  *
 237  * Walk @crtc's DRM device's mode_config and see if it's in use.
 238  *
 239  * RETURNS:
 240  * True if @crtc is part of the mode_config, false otherwise.
 241  */
 242 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 243 {
 244         struct drm_encoder *encoder;
 245         struct drm_device *dev = crtc->dev;
 246         /* FIXME: Locking around list access? */
 247         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
 248                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 249                         return true;
 250         return false;
 251 }
 252 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 253
 254 static void
 255 drm_encoder_disable(struct drm_encoder *encoder)
 256 {
 257         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 258
 259         if (encoder_funcs->disable)
 260                 (*encoder_funcs->disable)(encoder);
 261         else
 262                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 263 }
 264
 265 /**
 266  * drm_helper_disable_unused_functions - disable unused objects
 267  * @dev: DRM device
 268  *
 269  * LOCKING:
 270  * Caller must hold mode config lock.
 271  *
 272  * If an connector or CRTC isn't part of @dev's mode_config, it can be disabled
 273  * by calling its dpms function, which should power it off.
 274  */
 275 void drm_helper_disable_unused_functions(struct drm_device *dev)
 276 {
 277         struct drm_encoder *encoder;
 278         struct drm_connector *connector;
 279         struct drm_crtc *crtc;
 280
 281         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 282                 if (!connector->encoder)
 283                         continue;
 284                 if (connector->status == connector_status_disconnected)
 285                         connector->encoder = NULL;
 286         }
 287
 288         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 289                 if (!drm_helper_encoder_in_use(encoder)) {
 290                         drm_encoder_disable(encoder);
 291                         /* disconnector encoder from any connector */
 292                         encoder->crtc = NULL;
 293                 }
 294         }
 295
 296         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 297                 struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 298                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 299                 if (!crtc->enabled) {
 300                         if (crtc_funcs->disable)
 301                                 (*crtc_funcs->disable)(crtc);
 302                         else
 303                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 304                         crtc->fb = NULL;
 305                 }
 306         }
 307 }
 308 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 309
 310 /**
 311  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
 312  * @encoder: encoder to test
 313  * @crtc: crtc to test
 314  *
 315  * Return false if @encoder can't be driven by @crtc, true otherwise.
 316  */
 317 static bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
 318                                 struct drm_crtc *crtc)
 319 {
 320         struct drm_device *dev;
 321         struct drm_crtc *tmp;
 322         int crtc_mask = 1;
 323
 324         WARN(!crtc, "checking null crtc?\n");
 325
 326         dev = crtc->dev;
 327
 328         list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
 329                 if (tmp == crtc)
 330                         break;
 331                 crtc_mask <<= 1;
 332         }
 333
 334         if (encoder->possible_crtcs & crtc_mask)
 335                 return true;
 336         return false;
 337 }
 338
 339 /*
 340  * Check the CRTC we're going to map each output to vs. its current
 341  * CRTC.  If they don't match, we have to disable the output and the CRTC
 342  * since the driver will have to re-route things.
 343  */
 344 static void
 345 drm_crtc_prepare_encoders(struct drm_device *dev)
 346 {
 347         struct drm_encoder_helper_funcs *encoder_funcs;
 348         struct drm_encoder *encoder;
 349
 350         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 351                 encoder_funcs = encoder->helper_private;
 352                 /* Disable unused encoders */
 353                 if (encoder->crtc == NULL)
 354                         drm_encoder_disable(encoder);
 355                 /* Disable encoders whose CRTC is about to change */
 356                 if (encoder_funcs->get_crtc &&
 357                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 358                         drm_encoder_disable(encoder);
 359         }
 360 }
 361
 362 /**
 363  * drm_crtc_helper_set_mode - internal helper to set a mode
 364  * @crtc: CRTC to program
 365  * @mode: mode to use
 366  * @x: horizontal offset into the surface
 367  * @y: vertical offset into the surface
 368  * @old_fb: old framebuffer, for cleanup
 369  *
 370  * LOCKING:
 371  * Caller must hold mode config lock.
 372  *
 373  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 374  * to fixup or reject the mode prior to trying to set it. This is an internal
 375  * helper that drivers could e.g. use to update properties that require the
 376  * entire output pipe to be disabled and re-enabled in a new configuration. For
 377  * example for changing whether audio is enabled on a hdmi link or for changing
 378  * panel fitter or dither attributes. It is also called by the
 379  * drm_crtc_helper_set_config() helper function to drive the mode setting
 380  * sequence.
 381  *
 382  * RETURNS:
 383  * True if the mode was set successfully, or false otherwise.
 384  */
 385 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 386                               struct drm_display_mode *mode,
 387                               int x, int y,
 388                               struct drm_framebuffer *old_fb)
 389 {
 390         struct drm_device *dev = crtc->dev;
 391         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 392         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 393         struct drm_encoder_helper_funcs *encoder_funcs;
 394         int saved_x, saved_y;
 395         struct drm_encoder *encoder;
 396         bool ret = true;
 397
 398         crtc->enabled = drm_helper_crtc_in_use(crtc);
 399         if (!crtc->enabled)
 400                 return true;
 401
 402         adjusted_mode = drm_mode_duplicate(dev, mode);
 403         if (!adjusted_mode)
 404                 return false;
 405
 406         saved_hwmode = crtc->hwmode;
 407         saved_mode = crtc->mode;
 408         saved_x = crtc->x;
 409         saved_y = crtc->y;
 410
 411         /* Update crtc values up front so the driver can rely on them for mode
 412          * setting.
 413          */
 414         crtc->mode = *mode;
 415         crtc->x = x;
 416         crtc->y = y;
 417
 418         /* Pass our mode to the connectors and the CRTC to give them a chance to
 419          * adjust it according to limitations or connector properties, and also
 420          * a chance to reject the mode entirely.
 421          */
 422         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 423
 424                 if (encoder->crtc != crtc)
 425                         continue;
 426                 encoder_funcs = encoder->helper_private;
 427                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 428                                                       adjusted_mode))) {
 429                         DRM_DEBUG_KMS("Encoder fixup failed\n");
 430                         goto done;
 431                 }
 432         }
 433
 434         if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
 435                 DRM_DEBUG_KMS("CRTC fixup failed\n");
 436                 goto done;
 437         }
 438         DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);
 439
 440         /* Prepare the encoders and CRTCs before setting the mode. */
 441         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 442
 443                 if (encoder->crtc != crtc)
 444                         continue;
 445                 encoder_funcs = encoder->helper_private;
 446                 /* Disable the encoders as the first thing we do. */
 447                 encoder_funcs->prepare(encoder);
 448         }
 449
 450         drm_crtc_prepare_encoders(dev);
 451
 452         crtc_funcs->prepare(crtc);
 453
 454         /* Set up the DPLL and any encoders state that needs to adjust or depend
 455          * on the DPLL.
 456          */
 457         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 458         if (!ret)
 459             goto done;
 460
 461         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 462
 463                 if (encoder->crtc != crtc)
 464                         continue;
 465
 466                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
 467                         encoder->base.id, drm_get_encoder_name(encoder),
 468                         mode->base.id, mode->name);
 469                 encoder_funcs = encoder->helper_private;
 470                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 471         }
 472
 473         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 474         crtc_funcs->commit(crtc);
 475
 476         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 477
 478                 if (encoder->crtc != crtc)
 479                         continue;
 480
 481                 encoder_funcs = encoder->helper_private;
 482                 encoder_funcs->commit(encoder);
 483
 484         }
 485
 486         /* Store real post-adjustment hardware mode. */
 487         crtc->hwmode = *adjusted_mode;
 488
 489         /* Calculate and store various constants which
 490          * are later needed by vblank and swap-completion
 491          * timestamping. They are derived from true hwmode.
 492          */
 493         drm_calc_timestamping_constants(crtc);
 494
 495         /* FIXME: add subpixel order */
 496 done:
 497         drm_mode_destroy(dev, adjusted_mode);
 498         if (!ret) {
 499                 crtc->hwmode = saved_hwmode;
 500                 crtc->mode = saved_mode;
 501                 crtc->x = saved_x;
 502                 crtc->y = saved_y;
 503         }
 504
 505         return ret;
 506 }
 507 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 508
 509
 510 static int
 511 drm_crtc_helper_disable(struct drm_crtc *crtc)
 512 {
 513         struct drm_device *dev = crtc->dev;
 514         struct drm_connector *connector;
 515         struct drm_encoder *encoder;
 516
 517         /* Decouple all encoders and their attached connectors from this crtc */
 518         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 519                 if (encoder->crtc != crtc)
 520                         continue;
 521
 522                 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 523                         if (connector->encoder != encoder)
 524                                 continue;
 525
 526                         connector->encoder = NULL;
 527                 }
 528         }
 529
 530         drm_helper_disable_unused_functions(dev);
 531         return 0;
 532 }
 533
 534 /**
 535  * drm_crtc_helper_set_config - set a new config from userspace
 536  * @set: mode set configuration
 537  *
 538  * LOCKING:
 539  * Caller must hold mode config lock.
 540  *
 541  * Setup a new configuration, provided by the upper layers (either an ioctl call
 542  * from userspace or internally e.g. from the fbdev suppport code) in @set, and
 543  * enable it. This is the main helper functions for drivers that implement
 544  * kernel mode setting with the crtc helper functions and the assorted
 545  * ->prepare(), ->modeset() and ->commit() helper callbacks.
 546  *
 547  * RETURNS:
 548  * Returns 0 on success, -ERRNO on failure.
 549  */
 550 int drm_crtc_helper_set_config(struct drm_mode_set *set)
 551 {
 552         struct drm_device *dev;
 553         struct drm_crtc *save_crtcs, *new_crtc, *crtc;
 554         struct drm_encoder *save_encoders, *new_encoder, *encoder;
 555         struct drm_framebuffer *old_fb = NULL;
 556         bool mode_changed = false; /* if true do a full mode set */
 557         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 558         struct drm_connector *save_connectors, *connector;
 559         int count = 0, ro, fail = 0;
 560         struct drm_crtc_helper_funcs *crtc_funcs;
 561         struct drm_mode_set save_set;
 562         int ret;
 563         int i;
 564
 565         DRM_DEBUG_KMS("\n");
 566
 567         if (!set)
 568                 return -EINVAL;
 569
 570         if (!set->crtc)
 571                 return -EINVAL;
 572
 573         if (!set->crtc->helper_private)
 574                 return -EINVAL;
 575
 576         crtc_funcs = set->crtc->helper_private;
 577
 578         if (!set->mode)
 579                 set->fb = NULL;
 580
 581         if (set->fb) {
 582                 DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 583                                 set->crtc->base.id, set->fb->base.id,
 584                                 (int)set->num_connectors, set->x, set->y);
 585         } else {
 586                 DRM_DEBUG_KMS("[CRTC:%d] [NOFB]\n", set->crtc->base.id);
 587                 return drm_crtc_helper_disable(set->crtc);
 588         }
 589
 590         dev = set->crtc->dev;
 591
 592         /* Allocate space for the backup of all (non-pointer) crtc, encoder and
 593          * connector data. */
 594         save_crtcs = kzalloc(dev->mode_config.num_crtc *
 595                              sizeof(struct drm_crtc), GFP_KERNEL);
 596         if (!save_crtcs)
 597                 return -ENOMEM;
 598
 599         save_encoders = kzalloc(dev->mode_config.num_encoder *
 600                                 sizeof(struct drm_encoder), GFP_KERNEL);
 601         if (!save_encoders) {
 602                 kfree(save_crtcs);
 603                 return -ENOMEM;
 604         }
 605
 606         save_connectors = kzalloc(dev->mode_config.num_connector *
 607                                 sizeof(struct drm_connector), GFP_KERNEL);
 608         if (!save_connectors) {
 609                 kfree(save_crtcs);
 610                 kfree(save_encoders);
 611                 return -ENOMEM;
 612         }
 613
 614         /* Copy data. Note that driver private data is not affected.
 615          * Should anything bad happen only the expected state is
 616          * restored, not the drivers personal bookkeeping.
 617          */
 618         count = 0;
 619         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 620                 save_crtcs[count++] = *crtc;
 621         }
 622
 623         count = 0;
 624         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 625                 save_encoders[count++] = *encoder;
 626         }
 627
 628         count = 0;
 629         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 630                 save_connectors[count++] = *connector;
 631         }
 632
 633         save_set.crtc = set->crtc;
 634         save_set.mode = &set->crtc->mode;
 635         save_set.x = set->crtc->x;
 636         save_set.y = set->crtc->y;
 637         save_set.fb = set->crtc->fb;
 638
 639         /* We should be able to check here if the fb has the same properties
 640          * and then just flip_or_move it */
 641         if (set->crtc->fb != set->fb) {
 642                 /* If we have no fb then treat it as a full mode set */
 643                 if (set->crtc->fb == NULL) {
 644                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 645                         mode_changed = true;
 646                 } else if (set->fb == NULL) {
 647                         mode_changed = true;
 648                 } else if (set->fb->depth != set->crtc->fb->depth) {
 649                         mode_changed = true;
 650                 } else if (set->fb->bits_per_pixel !=
 651                            set->crtc->fb->bits_per_pixel) {
 652                         mode_changed = true;
 653                 } else if (set->fb->pixel_format !=
 654                            set->crtc->fb->pixel_format) {
 655                         mode_changed = true;
 656                 } else
 657                         fb_changed = true;
 658         }
 659
 660         if (set->x != set->crtc->x || set->y != set->crtc->y)
 661                 fb_changed = true;
 662
 663         if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
 664                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 665                 drm_mode_debug_printmodeline(&set->crtc->mode);
 666                 drm_mode_debug_printmodeline(set->mode);
 667                 mode_changed = true;
 668         }
 669
 670         /* a) traverse passed in connector list and get encoders for them */
 671         count = 0;
 672         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 673                 struct drm_connector_helper_funcs *connector_funcs =
 674                         connector->helper_private;
 675                 new_encoder = connector->encoder;
 676                 for (ro = 0; ro < set->num_connectors; ro++) {
 677                         if (set->connectors[ro] == connector) {
 678                                 new_encoder = connector_funcs->best_encoder(connector);
 679                                 /* if we can't get an encoder for a connector
 680                                    we are setting now - then fail */
 681                                 if (new_encoder == NULL)
 682                                         /* don't break so fail path works correct */
 683                                         fail = 1;
 684                                 break;
 685                         }
 686                 }
 687
 688                 if (new_encoder != connector->encoder) {
 689                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 690                         mode_changed = true;
 691                         /* If the encoder is reused for another connector, then
 692                          * the appropriate crtc will be set later.
 693                          */
 694                         if (connector->encoder)
 695                                 connector->encoder->crtc = NULL;
 696                         connector->encoder = new_encoder;
 697                 }
 698         }
 699
 700         if (fail) {
 701                 ret = -EINVAL;
 702                 goto fail;
 703         }
 704
 705         count = 0;
 706         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 707                 if (!connector->encoder)
 708                         continue;
 709
 710                 if (connector->encoder->crtc == set->crtc)
 711                         new_crtc = NULL;
 712                 else
 713                         new_crtc = connector->encoder->crtc;
 714
 715                 for (ro = 0; ro < set->num_connectors; ro++) {
 716                         if (set->connectors[ro] == connector)
 717                                 new_crtc = set->crtc;
 718                 }
 719
 720                 /* Make sure the new CRTC will work with the encoder */
 721                 if (new_crtc &&
 722                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 723                         ret = -EINVAL;
 724                         goto fail;
 725                 }
 726                 if (new_crtc != connector->encoder->crtc) {
 727                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 728                         mode_changed = true;
 729                         connector->encoder->crtc = new_crtc;
 730                 }
 731                 if (new_crtc) {
 732                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 733                                 connector->base.id, drm_get_connector_name(connector),
 734                                 new_crtc->base.id);
 735                 } else {
 736                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 737                                 connector->base.id, drm_get_connector_name(connector));
 738                 }
 739         }
 740
 741         /* mode_set_base is not a required function */
 742         if (fb_changed && !crtc_funcs->mode_set_base)
 743                 mode_changed = true;
 744
 745         if (mode_changed) {
 746                 set->crtc->enabled = drm_helper_crtc_in_use(set->crtc);
 747                 if (set->crtc->enabled) {
 748                         DRM_DEBUG_KMS("attempting to set mode from"
 749                                         " userspace\n");
 750                         drm_mode_debug_printmodeline(set->mode);
 751                         old_fb = set->crtc->fb;
 752                         set->crtc->fb = set->fb;
 753                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 754                                                       set->x, set->y,
 755                                                       old_fb)) {
 756                                 DRM_ERROR("failed to set mode on [CRTC:%d]\n",
 757                                           set->crtc->base.id);
 758                                 set->crtc->fb = old_fb;
 759                                 ret = -EINVAL;
 760                                 goto fail;
 761                         }
 762                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 763                         for (i = 0; i < set->num_connectors; i++) {
 764                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 765                                               drm_get_connector_name(set->connectors[i]));
 766                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 767                         }
 768                 }
 769                 drm_helper_disable_unused_functions(dev);
 770         } else if (fb_changed) {
 771                 set->crtc->x = set->x;
 772                 set->crtc->y = set->y;
 773
 774                 old_fb = set->crtc->fb;
 775                 if (set->crtc->fb != set->fb)
 776                         set->crtc->fb = set->fb;
 777                 ret = crtc_funcs->mode_set_base(set->crtc,
 778                                                 set->x, set->y, old_fb);
 779                 if (ret != 0) {
 780                         set->crtc->fb = old_fb;
 781                         goto fail;
 782                 }
 783         }
 784
 785         kfree(save_connectors);
 786         kfree(save_encoders);
 787         kfree(save_crtcs);
 788         return 0;
 789
 790 fail:
 791         /* Restore all previous data. */
 792         count = 0;
 793         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 794                 *crtc = save_crtcs[count++];
 795         }
 796
 797         count = 0;
 798         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 799                 *encoder = save_encoders[count++];
 800         }
 801
 802         count = 0;
 803         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 804                 *connector = save_connectors[count++];
 805         }
 806
 807         /* Try to restore the config */
 808         if (mode_changed &&
 809             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 810                                       save_set.y, save_set.fb))
 811                 DRM_ERROR("failed to restore config after modeset failure\n");
 812
 813         kfree(save_connectors);
 814         kfree(save_encoders);
 815         kfree(save_crtcs);
 816         return ret;
 817 }
 818 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 819
 820 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 821 {
 822         int dpms = DRM_MODE_DPMS_OFF;
 823         struct drm_connector *connector;
 824         struct drm_device *dev = encoder->dev;
 825
 826         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 827                 if (connector->encoder == encoder)
 828                         if (connector->dpms < dpms)
 829                                 dpms = connector->dpms;
 830         return dpms;
 831 }
 832
 833 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 834 {
 835         int dpms = DRM_MODE_DPMS_OFF;
 836         struct drm_connector *connector;
 837         struct drm_device *dev = crtc->dev;
 838
 839         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 840                 if (connector->encoder && connector->encoder->crtc == crtc)
 841                         if (connector->dpms < dpms)
 842                                 dpms = connector->dpms;
 843         return dpms;
 844 }
 845
 846 /**
 847  * drm_helper_connector_dpms() - connector dpms helper implementation
 848  * @connector: affected connector
 849  * @mode: DPMS mode
 850  *
 851  * This is the main helper function provided by the crtc helper framework for
 852  * implementing the DPMS connector attribute. It computes the new desired DPMS
 853  * state for all encoders and crtcs in the output mesh and calls the ->dpms()
 854  * callback provided by the driver appropriately.
 855  */
 856 void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 857 {
 858         struct drm_encoder *encoder = connector->encoder;
 859         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 860         int old_dpms;
 861
 862         if (mode == connector->dpms)
 863                 return;
 864
 865         old_dpms = connector->dpms;
 866         connector->dpms = mode;
 867
 868         /* from off to on, do crtc then encoder */
 869         if (mode < old_dpms) {
 870                 if (crtc) {
 871                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 872                         if (crtc_funcs->dpms)
 873                                 (*crtc_funcs->dpms) (crtc,
 874                                                      drm_helper_choose_crtc_dpms(crtc));
 875                 }
 876                 if (encoder) {
 877                         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 878                         if (encoder_funcs->dpms)
 879                                 (*encoder_funcs->dpms) (encoder,
 880                                                         drm_helper_choose_encoder_dpms(encoder));
 881                 }
 882         }
 883
 884         /* from on to off, do encoder then crtc */
 885         if (mode > old_dpms) {
 886                 if (encoder) {
 887                         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 888                         if (encoder_funcs->dpms)
 889                                 (*encoder_funcs->dpms) (encoder,
 890                                                         drm_helper_choose_encoder_dpms(encoder));
 891                 }
 892                 if (crtc) {
 893                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 894                         if (crtc_funcs->dpms)
 895                                 (*crtc_funcs->dpms) (crtc,
 896                                                      drm_helper_choose_crtc_dpms(crtc));
 897                 }
 898         }
 899
 900         return;
 901 }
 902 EXPORT_SYMBOL(drm_helper_connector_dpms);
 903
 904 int drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
 905                                    struct drm_mode_fb_cmd2 *mode_cmd)
 906 {
 907         int i;
 908
 909         fb->width = mode_cmd->width;
 910         fb->height = mode_cmd->height;
 911         for (i = 0; i < 4; i++) {
 912                 fb->pitches[i] = mode_cmd->pitches[i];
 913                 fb->offsets[i] = mode_cmd->offsets[i];
 914         }
 915         drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
 916                                     &fb->bits_per_pixel);
 917         fb->pixel_format = mode_cmd->pixel_format;
 918
 919         return 0;
 920 }
 921 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
 922
 923 int drm_helper_resume_force_mode(struct drm_device *dev)
 924 {
 925         struct drm_crtc *crtc;
 926         struct drm_encoder *encoder;
 927         struct drm_encoder_helper_funcs *encoder_funcs;
 928         struct drm_crtc_helper_funcs *crtc_funcs;
 929         int ret;
 930
 931         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 932
 933                 if (!crtc->enabled)
 934                         continue;
 935
 936                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 937                                                crtc->x, crtc->y, crtc->fb);
 938
 939                 if (ret == false)
 940                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 941
 942                 /* Turn off outputs that were already powered off */
 943                 if (drm_helper_choose_crtc_dpms(crtc)) {
 944                         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 945
 946                                 if(encoder->crtc != crtc)
 947                                         continue;
 948
 949                                 encoder_funcs = encoder->helper_private;
 950                                 if (encoder_funcs->dpms)
 951                                         (*encoder_funcs->dpms) (encoder,
 952                                                                 drm_helper_choose_encoder_dpms(encoder));
 953                         }
 954
 955                         crtc_funcs = crtc->helper_private;
 956                         if (crtc_funcs->dpms)
 957                                 (*crtc_funcs->dpms) (crtc,
 958                                                      drm_helper_choose_crtc_dpms(crtc));
 959                 }
 960         }
 961         /* disable the unused connectors while restoring the modesetting */
 962         drm_helper_disable_unused_functions(dev);
 963         return 0;
 964 }
 965 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 966
 967 void drm_kms_helper_hotplug_event(struct drm_device *dev)
 968 {
 969         /* send a uevent + call fbdev */
 970         drm_sysfs_hotplug_event(dev);
 971         if (dev->mode_config.funcs->output_poll_changed)
 972                 dev->mode_config.funcs->output_poll_changed(dev);
 973 }
 974 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 975
 976 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
 977 static void output_poll_execute(struct work_struct *work)
 978 {
 979         struct delayed_work *delayed_work = to_delayed_work(work);
 980         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
 981         struct drm_connector *connector;
 982         enum drm_connector_status old_status;
 983         bool repoll = false, changed = false;
 984
 985         if (!drm_kms_helper_poll)
 986                 return;
 987
 988         mutex_lock(&dev->mode_config.mutex);
 989         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 990
 991                 /* Ignore forced connectors. */
 992                 if (connector->force)
 993                         continue;
 994
 995                 /* Ignore HPD capable connectors and connectors where we don't
 996                  * want any hotplug detection at all for polling. */
 997                 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
 998                         continue;
 999
1000                 repoll = true;
1001
1002                 old_status = connector->status;
1003                 /* if we are connected and don't want to poll for disconnect
1004                    skip it */
1005                 if (old_status == connector_status_connected &&
1006                     !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
1007                         continue;
1008
1009                 connector->status = connector->funcs->detect(connector, false);
1010                 if (old_status != connector->status) {
1011                         const char *old, *new;
1012
1013                         old = drm_get_connector_status_name(old_status);
1014                         new = drm_get_connector_status_name(connector->status);
1015
1016                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
1017                                       "status updated from %s to %s\n",
1018                                       connector->base.id,
1019                                       drm_get_connector_name(connector),
1020                                       old, new);
1021
1022                         changed = true;
1023                 }
1024         }
1025
1026         mutex_unlock(&dev->mode_config.mutex);
1027
1028         if (changed)
1029                 drm_kms_helper_hotplug_event(dev);
1030
1031         if (repoll)
1032                 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
1033 }
1034
1035 void drm_kms_helper_poll_disable(struct drm_device *dev)
1036 {
1037         if (!dev->mode_config.poll_enabled)
1038                 return;
1039         cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
1040 }
1041 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
1042
1043 void drm_kms_helper_poll_enable(struct drm_device *dev)
1044 {
1045         bool poll = false;
1046         struct drm_connector *connector;
1047
1048         if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
1049                 return;
1050
1051         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1052                 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
1053                                          DRM_CONNECTOR_POLL_DISCONNECT))
1054                         poll = true;
1055         }
1056
1057         if (poll)
1058                 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
1059 }
1060 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
1061
1062 void drm_kms_helper_poll_init(struct drm_device *dev)
1063 {
1064         INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
1065         dev->mode_config.poll_enabled = true;
1066
1067         drm_kms_helper_poll_enable(dev);
1068 }
1069 EXPORT_SYMBOL(drm_kms_helper_poll_init);
1070
1071 void drm_kms_helper_poll_fini(struct drm_device *dev)
1072 {
1073         drm_kms_helper_poll_disable(dev);
1074 }
1075 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
1076
1077 void drm_helper_hpd_irq_event(struct drm_device *dev)
1078 {
1079         struct drm_connector *connector;
1080         enum drm_connector_status old_status;
1081         bool changed = false;
1082
1083         if (!dev->mode_config.poll_enabled)
1084                 return;
1085
1086         mutex_lock(&dev->mode_config.mutex);
1087         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1088
1089                 /* Only handle HPD capable connectors. */
1090                 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1091                         continue;
1092
1093                 old_status = connector->status;
1094
1095                 connector->status = connector->funcs->detect(connector, false);
1096                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
1097                               connector->base.id,
1098                               drm_get_connector_name(connector),
1099                               drm_get_connector_status_name(old_status),
1100                               drm_get_connector_status_name(connector->status));
1101                 if (old_status != connector->status)
1102                         changed = true;
1103         }
1104
1105         mutex_unlock(&dev->mode_config.mutex);
1106
1107         if (changed)
1108                 drm_kms_helper_hotplug_event(dev);
1109 }
1110 EXPORT_SYMBOL(drm_helper_hpd_irq_event);