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/kernel.h>
  34 #include <linux/moduleparam.h>
  35
  36 #include <drm/drm_atomic.h>
  37 #include <drm/drm_atomic_helper.h>
  38 #include <drm/drm_atomic_uapi.h>
  39 #include <drm/drm_bridge.h>
  40 #include <drm/drm_crtc.h>
  41 #include <drm/drm_crtc_helper.h>
  42 #include <drm/drm_drv.h>
  43 #include <drm/drm_edid.h>
  44 #include <drm/drm_encoder.h>
  45 #include <drm/drm_fb_helper.h>
  46 #include <drm/drm_fourcc.h>
  47 #include <drm/drm_plane_helper.h>
  48 #include <drm/drm_print.h>
  49 #include <drm/drm_vblank.h>
  50
  51 /**
  52  * DOC: overview
  53  *
  54  * The CRTC modeset helper library provides a default set_config implementation
  55  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  56  * the same callbacks which drivers can use to e.g. restore the modeset
  57  * configuration on resume with drm_helper_resume_force_mode().
  58  *
  59  * Note that this helper library doesn't track the current power state of CRTCs
  60  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
  61  * though the hardware is already in the desired state. This deficiency has been
  62  * fixed in the atomic helpers.
  63  *
  64  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  65  * except for the handling of the primary plane: Atomic helpers require that the
  66  * primary plane is implemented as a real standalone plane and not directly tied
  67  * to the CRTC state. For easier transition this library provides functions to
  68  * implement the old semantics required by the CRTC helpers using the new plane
  69  * and atomic helper callbacks.
  70  *
  71  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  72  * converting to the plane helpers). New drivers must not use these functions
  73  * but need to implement the atomic interface instead, potentially using the
  74  * atomic helpers for that.
  75  *
  76  * These legacy modeset helpers use the same function table structures as
  77  * all other modesetting helpers. See the documentation for struct
  78  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
  79  * &drm_connector_helper_funcs.
  80  */
  81
  82 /**
  83  * drm_helper_encoder_in_use - check if a given encoder is in use
  84  * @encoder: encoder to check
  85  *
  86  * Checks whether @encoder is with the current mode setting output configuration
  87  * in use by any connector. This doesn't mean that it is actually enabled since
  88  * the DPMS state is tracked separately.
  89  *
  90  * Returns:
  91  * True if @encoder is used, false otherwise.
  92  */
  93 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
  94 {
  95         struct drm_connector *connector;
  96         struct drm_connector_list_iter conn_iter;
  97         struct drm_device *dev = encoder->dev;
  98
  99         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 100
 101         /*
 102          * We can expect this mutex to be locked if we are not panicking.
 103          * Locking is currently fubar in the panic handler.
 104          */
 105         if (!oops_in_progress) {
 106                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 107                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 108         }
 109
 110
 111         drm_connector_list_iter_begin(dev, &conn_iter);
 112         drm_for_each_connector_iter(connector, &conn_iter) {
 113                 if (connector->encoder == encoder) {
 114                         drm_connector_list_iter_end(&conn_iter);
 115                         return true;
 116                 }
 117         }
 118         drm_connector_list_iter_end(&conn_iter);
 119         return false;
 120 }
 121 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 122
 123 /**
 124  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 125  * @crtc: CRTC to check
 126  *
 127  * Checks whether @crtc is with the current mode setting output configuration
 128  * in use by any connector. This doesn't mean that it is actually enabled since
 129  * the DPMS state is tracked separately.
 130  *
 131  * Returns:
 132  * True if @crtc is used, false otherwise.
 133  */
 134 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 135 {
 136         struct drm_encoder *encoder;
 137         struct drm_device *dev = crtc->dev;
 138
 139         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 140
 141         /*
 142          * We can expect this mutex to be locked if we are not panicking.
 143          * Locking is currently fubar in the panic handler.
 144          */
 145         if (!oops_in_progress)
 146                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 147
 148         drm_for_each_encoder(encoder, dev)
 149                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 150                         return true;
 151         return false;
 152 }
 153 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 154
 155 static void
 156 drm_encoder_disable(struct drm_encoder *encoder)
 157 {
 158         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 159
 160         if (!encoder_funcs)
 161                 return;
 162
 163         if (encoder_funcs->disable)
 164                 (*encoder_funcs->disable)(encoder);
 165         else if (encoder_funcs->dpms)
 166                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 167 }
 168
 169 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 170 {
 171         struct drm_encoder *encoder;
 172         struct drm_crtc *crtc;
 173
 174         drm_warn_on_modeset_not_all_locked(dev);
 175
 176         drm_for_each_encoder(encoder, dev) {
 177                 if (!drm_helper_encoder_in_use(encoder)) {
 178                         drm_encoder_disable(encoder);
 179                         /* disconnect encoder from any connector */
 180                         encoder->crtc = NULL;
 181                 }
 182         }
 183
 184         drm_for_each_crtc(crtc, dev) {
 185                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 186                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 187                 if (!crtc->enabled) {
 188                         if (crtc_funcs->disable)
 189                                 (*crtc_funcs->disable)(crtc);
 190                         else
 191                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 192                         crtc->primary->fb = NULL;
 193                 }
 194         }
 195 }
 196
 197 /**
 198  * drm_helper_disable_unused_functions - disable unused objects
 199  * @dev: DRM device
 200  *
 201  * This function walks through the entire mode setting configuration of @dev. It
 202  * will remove any CRTC links of unused encoders and encoder links of
 203  * disconnected connectors. Then it will disable all unused encoders and CRTCs
 204  * either by calling their disable callback if available or by calling their
 205  * dpms callback with DRM_MODE_DPMS_OFF.
 206  *
 207  * NOTE:
 208  *
 209  * This function is part of the legacy modeset helper library and will cause
 210  * major confusion with atomic drivers. This is because atomic helpers guarantee
 211  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
 212  * on an enabled functions. drm_helper_disable_unused_functions() on the other
 213  * hand throws such guarantees into the wind and calls disable hooks
 214  * unconditionally on unused functions.
 215  */
 216 void drm_helper_disable_unused_functions(struct drm_device *dev)
 217 {
 218         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 219
 220         drm_modeset_lock_all(dev);
 221         __drm_helper_disable_unused_functions(dev);
 222         drm_modeset_unlock_all(dev);
 223 }
 224 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 225
 226 /*
 227  * Check the CRTC we're going to map each output to vs. its current
 228  * CRTC.  If they don't match, we have to disable the output and the CRTC
 229  * since the driver will have to re-route things.
 230  */
 231 static void
 232 drm_crtc_prepare_encoders(struct drm_device *dev)
 233 {
 234         const struct drm_encoder_helper_funcs *encoder_funcs;
 235         struct drm_encoder *encoder;
 236
 237         drm_for_each_encoder(encoder, dev) {
 238                 encoder_funcs = encoder->helper_private;
 239                 if (!encoder_funcs)
 240                         continue;
 241
 242                 /* Disable unused encoders */
 243                 if (encoder->crtc == NULL)
 244                         drm_encoder_disable(encoder);
 245                 /* Disable encoders whose CRTC is about to change */
 246                 if (encoder_funcs->get_crtc &&
 247                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 248                         drm_encoder_disable(encoder);
 249         }
 250 }
 251
 252 /**
 253  * drm_crtc_helper_set_mode - internal helper to set a mode
 254  * @crtc: CRTC to program
 255  * @mode: mode to use
 256  * @x: horizontal offset into the surface
 257  * @y: vertical offset into the surface
 258  * @old_fb: old framebuffer, for cleanup
 259  *
 260  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 261  * to fixup or reject the mode prior to trying to set it. This is an internal
 262  * helper that drivers could e.g. use to update properties that require the
 263  * entire output pipe to be disabled and re-enabled in a new configuration. For
 264  * example for changing whether audio is enabled on a hdmi link or for changing
 265  * panel fitter or dither attributes. It is also called by the
 266  * drm_crtc_helper_set_config() helper function to drive the mode setting
 267  * sequence.
 268  *
 269  * Returns:
 270  * True if the mode was set successfully, false otherwise.
 271  */
 272 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 273                               struct drm_display_mode *mode,
 274                               int x, int y,
 275                               struct drm_framebuffer *old_fb)
 276 {
 277         struct drm_device *dev = crtc->dev;
 278         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 279         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 280         const struct drm_encoder_helper_funcs *encoder_funcs;
 281         int saved_x, saved_y;
 282         bool saved_enabled;
 283         struct drm_encoder *encoder;
 284         bool ret = true;
 285
 286         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 287
 288         drm_warn_on_modeset_not_all_locked(dev);
 289
 290         saved_enabled = crtc->enabled;
 291         crtc->enabled = drm_helper_crtc_in_use(crtc);
 292         if (!crtc->enabled)
 293                 return true;
 294
 295         adjusted_mode = drm_mode_duplicate(dev, mode);
 296         if (!adjusted_mode) {
 297                 crtc->enabled = saved_enabled;
 298                 return false;
 299         }
 300
 301         saved_mode = crtc->mode;
 302         saved_hwmode = crtc->hwmode;
 303         saved_x = crtc->x;
 304         saved_y = crtc->y;
 305
 306         /* Update crtc values up front so the driver can rely on them for mode
 307          * setting.
 308          */
 309         crtc->mode = *mode;
 310         crtc->x = x;
 311         crtc->y = y;
 312
 313         /* Pass our mode to the connectors and the CRTC to give them a chance to
 314          * adjust it according to limitations or connector properties, and also
 315          * a chance to reject the mode entirely.
 316          */
 317         drm_for_each_encoder(encoder, dev) {
 318
 319                 if (encoder->crtc != crtc)
 320                         continue;
 321
 322                 encoder_funcs = encoder->helper_private;
 323                 if (!encoder_funcs)
 324                         continue;
 325
 326                 encoder_funcs = encoder->helper_private;
 327                 if (encoder_funcs->mode_fixup) {
 328                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 329                                                               adjusted_mode))) {
 330                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 331                                 goto done;
 332                         }
 333                 }
 334         }
 335
 336         if (crtc_funcs->mode_fixup) {
 337                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 338                                                 adjusted_mode))) {
 339                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 340                         goto done;
 341                 }
 342         }
 343         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 344
 345         crtc->hwmode = *adjusted_mode;
 346
 347         /* Prepare the encoders and CRTCs before setting the mode. */
 348         drm_for_each_encoder(encoder, dev) {
 349
 350                 if (encoder->crtc != crtc)
 351                         continue;
 352
 353                 encoder_funcs = encoder->helper_private;
 354                 if (!encoder_funcs)
 355                         continue;
 356
 357                 /* Disable the encoders as the first thing we do. */
 358                 if (encoder_funcs->prepare)
 359                         encoder_funcs->prepare(encoder);
 360         }
 361
 362         drm_crtc_prepare_encoders(dev);
 363
 364         crtc_funcs->prepare(crtc);
 365
 366         /* Set up the DPLL and any encoders state that needs to adjust or depend
 367          * on the DPLL.
 368          */
 369         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 370         if (!ret)
 371             goto done;
 372
 373         drm_for_each_encoder(encoder, dev) {
 374
 375                 if (encoder->crtc != crtc)
 376                         continue;
 377
 378                 encoder_funcs = encoder->helper_private;
 379                 if (!encoder_funcs)
 380                         continue;
 381
 382                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 383                         encoder->base.id, encoder->name, mode->name);
 384                 if (encoder_funcs->mode_set)
 385                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 386         }
 387
 388         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 389         crtc_funcs->commit(crtc);
 390
 391         drm_for_each_encoder(encoder, dev) {
 392
 393                 if (encoder->crtc != crtc)
 394                         continue;
 395
 396                 encoder_funcs = encoder->helper_private;
 397                 if (!encoder_funcs)
 398                         continue;
 399
 400                 if (encoder_funcs->commit)
 401                         encoder_funcs->commit(encoder);
 402         }
 403
 404         /* Calculate and store various constants which
 405          * are later needed by vblank and swap-completion
 406          * timestamping. They are derived from true hwmode.
 407          */
 408         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 409
 410         /* FIXME: add subpixel order */
 411 done:
 412         drm_mode_destroy(dev, adjusted_mode);
 413         if (!ret) {
 414                 crtc->enabled = saved_enabled;
 415                 crtc->mode = saved_mode;
 416                 crtc->hwmode = saved_hwmode;
 417                 crtc->x = saved_x;
 418                 crtc->y = saved_y;
 419         }
 420
 421         return ret;
 422 }
 423 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 424
 425 static void
 426 drm_crtc_helper_disable(struct drm_crtc *crtc)
 427 {
 428         struct drm_device *dev = crtc->dev;
 429         struct drm_connector *connector;
 430         struct drm_encoder *encoder;
 431
 432         /* Decouple all encoders and their attached connectors from this crtc */
 433         drm_for_each_encoder(encoder, dev) {
 434                 struct drm_connector_list_iter conn_iter;
 435
 436                 if (encoder->crtc != crtc)
 437                         continue;
 438
 439                 drm_connector_list_iter_begin(dev, &conn_iter);
 440                 drm_for_each_connector_iter(connector, &conn_iter) {
 441                         if (connector->encoder != encoder)
 442                                 continue;
 443
 444                         connector->encoder = NULL;
 445
 446                         /*
 447                          * drm_helper_disable_unused_functions() ought to be
 448                          * doing this, but since we've decoupled the encoder
 449                          * from the connector above, the required connection
 450                          * between them is henceforth no longer available.
 451                          */
 452                         connector->dpms = DRM_MODE_DPMS_OFF;
 453
 454                         /* we keep a reference while the encoder is bound */
 455                         drm_connector_put(connector);
 456                 }
 457                 drm_connector_list_iter_end(&conn_iter);
 458         }
 459
 460         __drm_helper_disable_unused_functions(dev);
 461 }
 462
 463 /*
 464  * For connectors that support multiple encoders, either the
 465  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
 466  */
 467 struct drm_encoder *
 468 drm_connector_get_single_encoder(struct drm_connector *connector)
 469 {
 470         struct drm_encoder *encoder;
 471
 472         WARN_ON(hweight32(connector->possible_encoders) > 1);
 473         drm_connector_for_each_possible_encoder(connector, encoder)
 474                 return encoder;
 475
 476         return NULL;
 477 }
 478
 479 /**
 480  * drm_crtc_helper_set_config - set a new config from userspace
 481  * @set: mode set configuration
 482  * @ctx: lock acquire context, not used here
 483  *
 484  * The drm_crtc_helper_set_config() helper function implements the of
 485  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
 486  * helpers.
 487  *
 488  * It first tries to locate the best encoder for each connector by calling the
 489  * connector @drm_connector_helper_funcs.best_encoder helper operation.
 490  *
 491  * After locating the appropriate encoders, the helper function will call the
 492  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
 493  * or reject it completely in which case an error will be returned to the
 494  * application. If the new configuration after mode adjustment is identical to
 495  * the current configuration the helper function will return without performing
 496  * any other operation.
 497  *
 498  * If the adjusted mode is identical to the current mode but changes to the
 499  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
 500  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
 501  *
 502  * If the adjusted mode differs from the current mode, or if the
 503  * ->mode_set_base() helper operation is not provided, the helper function
 504  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
 505  * and ->commit() CRTC and encoder helper operations, in that order.
 506  * Alternatively it can also use the dpms and disable helper operations. For
 507  * details see &struct drm_crtc_helper_funcs and struct
 508  * &drm_encoder_helper_funcs.
 509  *
 510  * This function is deprecated.  New drivers must implement atomic modeset
 511  * support, for which this function is unsuitable. Instead drivers should use
 512  * drm_atomic_helper_set_config().
 513  *
 514  * Returns:
 515  * Returns 0 on success, negative errno numbers on failure.
 516  */
 517 int drm_crtc_helper_set_config(struct drm_mode_set *set,
 518                                struct drm_modeset_acquire_ctx *ctx)
 519 {
 520         struct drm_device *dev;
 521         struct drm_crtc **save_encoder_crtcs, *new_crtc;
 522         struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
 523         bool mode_changed = false; /* if true do a full mode set */
 524         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 525         struct drm_connector *connector;
 526         struct drm_connector_list_iter conn_iter;
 527         int count = 0, ro, fail = 0;
 528         const struct drm_crtc_helper_funcs *crtc_funcs;
 529         struct drm_mode_set save_set;
 530         int ret;
 531         int i;
 532
 533         DRM_DEBUG_KMS("\n");
 534
 535         BUG_ON(!set);
 536         BUG_ON(!set->crtc);
 537         BUG_ON(!set->crtc->helper_private);
 538
 539         /* Enforce sane interface api - has been abused by the fb helper. */
 540         BUG_ON(!set->mode && set->fb);
 541         BUG_ON(set->fb && set->num_connectors == 0);
 542
 543         crtc_funcs = set->crtc->helper_private;
 544
 545         dev = set->crtc->dev;
 546         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 547
 548         if (!set->mode)
 549                 set->fb = NULL;
 550
 551         if (set->fb) {
 552                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 553                               set->crtc->base.id, set->crtc->name,
 554                               set->fb->base.id,
 555                               (int)set->num_connectors, set->x, set->y);
 556         } else {
 557                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 558                               set->crtc->base.id, set->crtc->name);
 559                 drm_crtc_helper_disable(set->crtc);
 560                 return 0;
 561         }
 562
 563         drm_warn_on_modeset_not_all_locked(dev);
 564
 565         /*
 566          * Allocate space for the backup of all (non-pointer) encoder and
 567          * connector data.
 568          */
 569         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 570                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 571         if (!save_encoder_crtcs)
 572                 return -ENOMEM;
 573
 574         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 575                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 576         if (!save_connector_encoders) {
 577                 kfree(save_encoder_crtcs);
 578                 return -ENOMEM;
 579         }
 580
 581         /*
 582          * Copy data. Note that driver private data is not affected.
 583          * Should anything bad happen only the expected state is
 584          * restored, not the drivers personal bookkeeping.
 585          */
 586         count = 0;
 587         drm_for_each_encoder(encoder, dev) {
 588                 save_encoder_crtcs[count++] = encoder->crtc;
 589         }
 590
 591         count = 0;
 592         drm_connector_list_iter_begin(dev, &conn_iter);
 593         drm_for_each_connector_iter(connector, &conn_iter)
 594                 save_connector_encoders[count++] = connector->encoder;
 595         drm_connector_list_iter_end(&conn_iter);
 596
 597         save_set.crtc = set->crtc;
 598         save_set.mode = &set->crtc->mode;
 599         save_set.x = set->crtc->x;
 600         save_set.y = set->crtc->y;
 601         save_set.fb = set->crtc->primary->fb;
 602
 603         /* We should be able to check here if the fb has the same properties
 604          * and then just flip_or_move it */
 605         if (set->crtc->primary->fb != set->fb) {
 606                 /* If we have no fb then treat it as a full mode set */
 607                 if (set->crtc->primary->fb == NULL) {
 608                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 609                         mode_changed = true;
 610                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 611                         mode_changed = true;
 612                 } else
 613                         fb_changed = true;
 614         }
 615
 616         if (set->x != set->crtc->x || set->y != set->crtc->y)
 617                 fb_changed = true;
 618
 619         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 620                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 621                 drm_mode_debug_printmodeline(&set->crtc->mode);
 622                 drm_mode_debug_printmodeline(set->mode);
 623                 mode_changed = true;
 624         }
 625
 626         /* take a reference on all unbound connectors in set, reuse the
 627          * already taken reference for bound connectors
 628          */
 629         for (ro = 0; ro < set->num_connectors; ro++) {
 630                 if (set->connectors[ro]->encoder)
 631                         continue;
 632                 drm_connector_get(set->connectors[ro]);
 633         }
 634
 635         /* a) traverse passed in connector list and get encoders for them */
 636         count = 0;
 637         drm_connector_list_iter_begin(dev, &conn_iter);
 638         drm_for_each_connector_iter(connector, &conn_iter) {
 639                 const struct drm_connector_helper_funcs *connector_funcs =
 640                         connector->helper_private;
 641                 new_encoder = connector->encoder;
 642                 for (ro = 0; ro < set->num_connectors; ro++) {
 643                         if (set->connectors[ro] == connector) {
 644                                 if (connector_funcs->best_encoder)
 645                                         new_encoder = connector_funcs->best_encoder(connector);
 646                                 else
 647                                         new_encoder = drm_connector_get_single_encoder(connector);
 648
 649                                 /* if we can't get an encoder for a connector
 650                                    we are setting now - then fail */
 651                                 if (new_encoder == NULL)
 652                                         /* don't break so fail path works correct */
 653                                         fail = 1;
 654
 655                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 656                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 657                                         mode_changed = true;
 658                                 }
 659
 660                                 break;
 661                         }
 662                 }
 663
 664                 if (new_encoder != connector->encoder) {
 665                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 666                         mode_changed = true;
 667                         /* If the encoder is reused for another connector, then
 668                          * the appropriate crtc will be set later.
 669                          */
 670                         if (connector->encoder)
 671                                 connector->encoder->crtc = NULL;
 672                         connector->encoder = new_encoder;
 673                 }
 674         }
 675         drm_connector_list_iter_end(&conn_iter);
 676
 677         if (fail) {
 678                 ret = -EINVAL;
 679                 goto fail;
 680         }
 681
 682         count = 0;
 683         drm_connector_list_iter_begin(dev, &conn_iter);
 684         drm_for_each_connector_iter(connector, &conn_iter) {
 685                 if (!connector->encoder)
 686                         continue;
 687
 688                 if (connector->encoder->crtc == set->crtc)
 689                         new_crtc = NULL;
 690                 else
 691                         new_crtc = connector->encoder->crtc;
 692
 693                 for (ro = 0; ro < set->num_connectors; ro++) {
 694                         if (set->connectors[ro] == connector)
 695                                 new_crtc = set->crtc;
 696                 }
 697
 698                 /* Make sure the new CRTC will work with the encoder */
 699                 if (new_crtc &&
 700                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 701                         ret = -EINVAL;
 702                         drm_connector_list_iter_end(&conn_iter);
 703                         goto fail;
 704                 }
 705                 if (new_crtc != connector->encoder->crtc) {
 706                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 707                         mode_changed = true;
 708                         connector->encoder->crtc = new_crtc;
 709                 }
 710                 if (new_crtc) {
 711                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
 712                                       connector->base.id, connector->name,
 713                                       new_crtc->base.id, new_crtc->name);
 714                 } else {
 715                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 716                                       connector->base.id, connector->name);
 717                 }
 718         }
 719         drm_connector_list_iter_end(&conn_iter);
 720
 721         /* mode_set_base is not a required function */
 722         if (fb_changed && !crtc_funcs->mode_set_base)
 723                 mode_changed = true;
 724
 725         if (mode_changed) {
 726                 if (drm_helper_crtc_in_use(set->crtc)) {
 727                         DRM_DEBUG_KMS("attempting to set mode from"
 728                                         " userspace\n");
 729                         drm_mode_debug_printmodeline(set->mode);
 730                         set->crtc->primary->fb = set->fb;
 731                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 732                                                       set->x, set->y,
 733                                                       save_set.fb)) {
 734                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
 735                                           set->crtc->base.id, set->crtc->name);
 736                                 set->crtc->primary->fb = save_set.fb;
 737                                 ret = -EINVAL;
 738                                 goto fail;
 739                         }
 740                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 741                         for (i = 0; i < set->num_connectors; i++) {
 742                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 743                                               set->connectors[i]->name);
 744                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 745                         }
 746                 }
 747                 __drm_helper_disable_unused_functions(dev);
 748         } else if (fb_changed) {
 749                 set->crtc->x = set->x;
 750                 set->crtc->y = set->y;
 751                 set->crtc->primary->fb = set->fb;
 752                 ret = crtc_funcs->mode_set_base(set->crtc,
 753                                                 set->x, set->y, save_set.fb);
 754                 if (ret != 0) {
 755                         set->crtc->x = save_set.x;
 756                         set->crtc->y = save_set.y;
 757                         set->crtc->primary->fb = save_set.fb;
 758                         goto fail;
 759                 }
 760         }
 761
 762         kfree(save_connector_encoders);
 763         kfree(save_encoder_crtcs);
 764         return 0;
 765
 766 fail:
 767         /* Restore all previous data. */
 768         count = 0;
 769         drm_for_each_encoder(encoder, dev) {
 770                 encoder->crtc = save_encoder_crtcs[count++];
 771         }
 772
 773         count = 0;
 774         drm_connector_list_iter_begin(dev, &conn_iter);
 775         drm_for_each_connector_iter(connector, &conn_iter)
 776                 connector->encoder = save_connector_encoders[count++];
 777         drm_connector_list_iter_end(&conn_iter);
 778
 779         /* after fail drop reference on all unbound connectors in set, let
 780          * bound connectors keep their reference
 781          */
 782         for (ro = 0; ro < set->num_connectors; ro++) {
 783                 if (set->connectors[ro]->encoder)
 784                         continue;
 785                 drm_connector_put(set->connectors[ro]);
 786         }
 787
 788         /* Try to restore the config */
 789         if (mode_changed &&
 790             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 791                                       save_set.y, save_set.fb))
 792                 DRM_ERROR("failed to restore config after modeset failure\n");
 793
 794         kfree(save_connector_encoders);
 795         kfree(save_encoder_crtcs);
 796         return ret;
 797 }
 798 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 799
 800 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 801 {
 802         int dpms = DRM_MODE_DPMS_OFF;
 803         struct drm_connector *connector;
 804         struct drm_connector_list_iter conn_iter;
 805         struct drm_device *dev = encoder->dev;
 806
 807         drm_connector_list_iter_begin(dev, &conn_iter);
 808         drm_for_each_connector_iter(connector, &conn_iter)
 809                 if (connector->encoder == encoder)
 810                         if (connector->dpms < dpms)
 811                                 dpms = connector->dpms;
 812         drm_connector_list_iter_end(&conn_iter);
 813
 814         return dpms;
 815 }
 816
 817 /* Helper which handles bridge ordering around encoder dpms */
 818 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 819 {
 820         const struct drm_encoder_helper_funcs *encoder_funcs;
 821
 822         encoder_funcs = encoder->helper_private;
 823         if (!encoder_funcs)
 824                 return;
 825
 826         if (encoder_funcs->dpms)
 827                 encoder_funcs->dpms(encoder, mode);
 828 }
 829
 830 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 831 {
 832         int dpms = DRM_MODE_DPMS_OFF;
 833         struct drm_connector *connector;
 834         struct drm_connector_list_iter conn_iter;
 835         struct drm_device *dev = crtc->dev;
 836
 837         drm_connector_list_iter_begin(dev, &conn_iter);
 838         drm_for_each_connector_iter(connector, &conn_iter)
 839                 if (connector->encoder && connector->encoder->crtc == crtc)
 840                         if (connector->dpms < dpms)
 841                                 dpms = connector->dpms;
 842         drm_connector_list_iter_end(&conn_iter);
 843
 844         return dpms;
 845 }
 846
 847 /**
 848  * drm_helper_connector_dpms() - connector dpms helper implementation
 849  * @connector: affected connector
 850  * @mode: DPMS mode
 851  *
 852  * The drm_helper_connector_dpms() helper function implements the
 853  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 854  * helpers.
 855  *
 856  * This is the main helper function provided by the CRTC helper framework for
 857  * implementing the DPMS connector attribute. It computes the new desired DPMS
 858  * state for all encoders and CRTCs in the output mesh and calls the
 859  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 860  * provided by the driver.
 861  *
 862  * This function is deprecated.  New drivers must implement atomic modeset
 863  * support, where DPMS is handled in the DRM core.
 864  *
 865  * Returns:
 866  * Always returns 0.
 867  */
 868 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 869 {
 870         struct drm_encoder *encoder = connector->encoder;
 871         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 872         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 873
 874         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 875
 876         if (mode == connector->dpms)
 877                 return 0;
 878
 879         old_dpms = connector->dpms;
 880         connector->dpms = mode;
 881
 882         if (encoder)
 883                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 884
 885         /* from off to on, do crtc then encoder */
 886         if (mode < old_dpms) {
 887                 if (crtc) {
 888                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 889                         if (crtc_funcs->dpms)
 890                                 (*crtc_funcs->dpms) (crtc,
 891                                                      drm_helper_choose_crtc_dpms(crtc));
 892                 }
 893                 if (encoder)
 894                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 895         }
 896
 897         /* from on to off, do encoder then crtc */
 898         if (mode > old_dpms) {
 899                 if (encoder)
 900                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 901                 if (crtc) {
 902                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 903                         if (crtc_funcs->dpms)
 904                                 (*crtc_funcs->dpms) (crtc,
 905                                                      drm_helper_choose_crtc_dpms(crtc));
 906                 }
 907         }
 908
 909         return 0;
 910 }
 911 EXPORT_SYMBOL(drm_helper_connector_dpms);
 912
 913 /**
 914  * drm_helper_resume_force_mode - force-restore mode setting configuration
 915  * @dev: drm_device which should be restored
 916  *
 917  * Drivers which use the mode setting helpers can use this function to
 918  * force-restore the mode setting configuration e.g. on resume or when something
 919  * else might have trampled over the hw state (like some overzealous old BIOSen
 920  * tended to do).
 921  *
 922  * This helper doesn't provide a error return value since restoring the old
 923  * config should never fail due to resource allocation issues since the driver
 924  * has successfully set the restored configuration already. Hence this should
 925  * boil down to the equivalent of a few dpms on calls, which also don't provide
 926  * an error code.
 927  *
 928  * Drivers where simply restoring an old configuration again might fail (e.g.
 929  * due to slight differences in allocating shared resources when the
 930  * configuration is restored in a different order than when userspace set it up)
 931  * need to use their own restore logic.
 932  *
 933  * This function is deprecated. New drivers should implement atomic mode-
 934  * setting and use the atomic suspend/resume helpers.
 935  *
 936  * See also:
 937  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 938  */
 939 void drm_helper_resume_force_mode(struct drm_device *dev)
 940 {
 941         struct drm_crtc *crtc;
 942         struct drm_encoder *encoder;
 943         const struct drm_crtc_helper_funcs *crtc_funcs;
 944         int encoder_dpms;
 945         bool ret;
 946
 947         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 948
 949         drm_modeset_lock_all(dev);
 950         drm_for_each_crtc(crtc, dev) {
 951
 952                 if (!crtc->enabled)
 953                         continue;
 954
 955                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 956                                                crtc->x, crtc->y, crtc->primary->fb);
 957
 958                 /* Restoring the old config should never fail! */
 959                 if (ret == false)
 960                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 961
 962                 /* Turn off outputs that were already powered off */
 963                 if (drm_helper_choose_crtc_dpms(crtc)) {
 964                         drm_for_each_encoder(encoder, dev) {
 965
 966                                 if(encoder->crtc != crtc)
 967                                         continue;
 968
 969                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 970                                                         encoder);
 971
 972                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 973                         }
 974
 975                         crtc_funcs = crtc->helper_private;
 976                         if (crtc_funcs->dpms)
 977                                 (*crtc_funcs->dpms) (crtc,
 978                                                      drm_helper_choose_crtc_dpms(crtc));
 979                 }
 980         }
 981
 982         /* disable the unused connectors while restoring the modesetting */
 983         __drm_helper_disable_unused_functions(dev);
 984         drm_modeset_unlock_all(dev);
 985 }
 986 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 987
 988 /**
 989  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
 990  * @dev: DRM device whose CRTCs to turn off
 991  *
 992  * Drivers may want to call this on unload to ensure that all displays are
 993  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
 994  *
 995  * Note: This should only be used by non-atomic legacy drivers. For an atomic
 996  * version look at drm_atomic_helper_shutdown().
 997  *
 998  * Returns:
 999  * Zero on success, error code on failure.
1000  */
1001 int drm_helper_force_disable_all(struct drm_device *dev)
1002 {
1003         struct drm_crtc *crtc;
1004         int ret = 0;
1005
1006         drm_modeset_lock_all(dev);
1007         drm_for_each_crtc(crtc, dev)
1008                 if (crtc->enabled) {
1009                         struct drm_mode_set set = {
1010                                 .crtc = crtc,
1011                         };
1012
1013                         ret = drm_mode_set_config_internal(&set);
1014                         if (ret)
1015                                 goto out;
1016                 }
1017 out:
1018         drm_modeset_unlock_all(dev);
1019         return ret;
1020 }
1021 EXPORT_SYMBOL(drm_helper_force_disable_all);