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 #include <linux/dynamic_debug.h>
  36
  37 #include <drm/drm_atomic.h>
  38 #include <drm/drm_atomic_helper.h>
  39 #include <drm/drm_atomic_uapi.h>
  40 #include <drm/drm_bridge.h>
  41 #include <drm/drm_crtc.h>
  42 #include <drm/drm_crtc_helper.h>
  43 #include <drm/drm_drv.h>
  44 #include <drm/drm_edid.h>
  45 #include <drm/drm_encoder.h>
  46 #include <drm/drm_fourcc.h>
  47 #include <drm/drm_framebuffer.h>
  48 #include <drm/drm_print.h>
  49 #include <drm/drm_vblank.h>
  50
  51 #include "drm_crtc_helper_internal.h"
  52
  53 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
  54                         "DRM_UT_CORE",
  55                         "DRM_UT_DRIVER",
  56                         "DRM_UT_KMS",
  57                         "DRM_UT_PRIME",
  58                         "DRM_UT_ATOMIC",
  59                         "DRM_UT_VBL",
  60                         "DRM_UT_STATE",
  61                         "DRM_UT_LEASE",
  62                         "DRM_UT_DP",
  63                         "DRM_UT_DRMRES");
  64
  65 /**
  66  * DOC: overview
  67  *
  68  * The CRTC modeset helper library provides a default set_config implementation
  69  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  70  * the same callbacks which drivers can use to e.g. restore the modeset
  71  * configuration on resume with drm_helper_resume_force_mode().
  72  *
  73  * Note that this helper library doesn't track the current power state of CRTCs
  74  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
  75  * though the hardware is already in the desired state. This deficiency has been
  76  * fixed in the atomic helpers.
  77  *
  78  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  79  * except for the handling of the primary plane: Atomic helpers require that the
  80  * primary plane is implemented as a real standalone plane and not directly tied
  81  * to the CRTC state. For easier transition this library provides functions to
  82  * implement the old semantics required by the CRTC helpers using the new plane
  83  * and atomic helper callbacks.
  84  *
  85  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  86  * converting to the plane helpers). New drivers must not use these functions
  87  * but need to implement the atomic interface instead, potentially using the
  88  * atomic helpers for that.
  89  *
  90  * These legacy modeset helpers use the same function table structures as
  91  * all other modesetting helpers. See the documentation for struct
  92  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
  93  * &drm_connector_helper_funcs.
  94  */
  95
  96 /**
  97  * drm_helper_encoder_in_use - check if a given encoder is in use
  98  * @encoder: encoder to check
  99  *
 100  * Checks whether @encoder is with the current mode setting output configuration
 101  * in use by any connector. This doesn't mean that it is actually enabled since
 102  * the DPMS state is tracked separately.
 103  *
 104  * Returns:
 105  * True if @encoder is used, false otherwise.
 106  */
 107 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
 108 {
 109         struct drm_connector *connector;
 110         struct drm_connector_list_iter conn_iter;
 111         struct drm_device *dev = encoder->dev;
 112
 113         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 114
 115         /*
 116          * We can expect this mutex to be locked if we are not panicking.
 117          * Locking is currently fubar in the panic handler.
 118          */
 119         if (!oops_in_progress) {
 120                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 121                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 122         }
 123
 124
 125         drm_connector_list_iter_begin(dev, &conn_iter);
 126         drm_for_each_connector_iter(connector, &conn_iter) {
 127                 if (connector->encoder == encoder) {
 128                         drm_connector_list_iter_end(&conn_iter);
 129                         return true;
 130                 }
 131         }
 132         drm_connector_list_iter_end(&conn_iter);
 133         return false;
 134 }
 135 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 136
 137 /**
 138  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 139  * @crtc: CRTC to check
 140  *
 141  * Checks whether @crtc is with the current mode setting output configuration
 142  * in use by any connector. This doesn't mean that it is actually enabled since
 143  * the DPMS state is tracked separately.
 144  *
 145  * Returns:
 146  * True if @crtc is used, false otherwise.
 147  */
 148 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 149 {
 150         struct drm_encoder *encoder;
 151         struct drm_device *dev = crtc->dev;
 152
 153         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 154
 155         /*
 156          * We can expect this mutex to be locked if we are not panicking.
 157          * Locking is currently fubar in the panic handler.
 158          */
 159         if (!oops_in_progress)
 160                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 161
 162         drm_for_each_encoder(encoder, dev)
 163                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 164                         return true;
 165         return false;
 166 }
 167 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 168
 169 static void
 170 drm_encoder_disable(struct drm_encoder *encoder)
 171 {
 172         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 173
 174         if (!encoder_funcs)
 175                 return;
 176
 177         if (encoder_funcs->disable)
 178                 (*encoder_funcs->disable)(encoder);
 179         else if (encoder_funcs->dpms)
 180                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 181 }
 182
 183 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 184 {
 185         struct drm_encoder *encoder;
 186         struct drm_crtc *crtc;
 187
 188         drm_warn_on_modeset_not_all_locked(dev);
 189
 190         drm_for_each_encoder(encoder, dev) {
 191                 if (!drm_helper_encoder_in_use(encoder)) {
 192                         drm_encoder_disable(encoder);
 193                         /* disconnect encoder from any connector */
 194                         encoder->crtc = NULL;
 195                 }
 196         }
 197
 198         drm_for_each_crtc(crtc, dev) {
 199                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 200
 201                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 202                 if (!crtc->enabled) {
 203                         if (crtc_funcs->disable)
 204                                 (*crtc_funcs->disable)(crtc);
 205                         else
 206                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 207                         crtc->primary->fb = NULL;
 208                 }
 209         }
 210 }
 211
 212 /**
 213  * drm_helper_disable_unused_functions - disable unused objects
 214  * @dev: DRM device
 215  *
 216  * This function walks through the entire mode setting configuration of @dev. It
 217  * will remove any CRTC links of unused encoders and encoder links of
 218  * disconnected connectors. Then it will disable all unused encoders and CRTCs
 219  * either by calling their disable callback if available or by calling their
 220  * dpms callback with DRM_MODE_DPMS_OFF.
 221  *
 222  * NOTE:
 223  *
 224  * This function is part of the legacy modeset helper library and will cause
 225  * major confusion with atomic drivers. This is because atomic helpers guarantee
 226  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
 227  * on an enabled functions. drm_helper_disable_unused_functions() on the other
 228  * hand throws such guarantees into the wind and calls disable hooks
 229  * unconditionally on unused functions.
 230  */
 231 void drm_helper_disable_unused_functions(struct drm_device *dev)
 232 {
 233         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 234
 235         drm_modeset_lock_all(dev);
 236         __drm_helper_disable_unused_functions(dev);
 237         drm_modeset_unlock_all(dev);
 238 }
 239 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 240
 241 /*
 242  * Check the CRTC we're going to map each output to vs. its current
 243  * CRTC.  If they don't match, we have to disable the output and the CRTC
 244  * since the driver will have to re-route things.
 245  */
 246 static void
 247 drm_crtc_prepare_encoders(struct drm_device *dev)
 248 {
 249         const struct drm_encoder_helper_funcs *encoder_funcs;
 250         struct drm_encoder *encoder;
 251
 252         drm_for_each_encoder(encoder, dev) {
 253                 encoder_funcs = encoder->helper_private;
 254                 if (!encoder_funcs)
 255                         continue;
 256
 257                 /* Disable unused encoders */
 258                 if (encoder->crtc == NULL)
 259                         drm_encoder_disable(encoder);
 260         }
 261 }
 262
 263 /**
 264  * drm_crtc_helper_set_mode - internal helper to set a mode
 265  * @crtc: CRTC to program
 266  * @mode: mode to use
 267  * @x: horizontal offset into the surface
 268  * @y: vertical offset into the surface
 269  * @old_fb: old framebuffer, for cleanup
 270  *
 271  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 272  * to fixup or reject the mode prior to trying to set it. This is an internal
 273  * helper that drivers could e.g. use to update properties that require the
 274  * entire output pipe to be disabled and re-enabled in a new configuration. For
 275  * example for changing whether audio is enabled on a hdmi link or for changing
 276  * panel fitter or dither attributes. It is also called by the
 277  * drm_crtc_helper_set_config() helper function to drive the mode setting
 278  * sequence.
 279  *
 280  * Returns:
 281  * True if the mode was set successfully, false otherwise.
 282  */
 283 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 284                               struct drm_display_mode *mode,
 285                               int x, int y,
 286                               struct drm_framebuffer *old_fb)
 287 {
 288         struct drm_device *dev = crtc->dev;
 289         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 290         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 291         const struct drm_encoder_helper_funcs *encoder_funcs;
 292         int saved_x, saved_y;
 293         bool saved_enabled;
 294         struct drm_encoder *encoder;
 295         bool ret = true;
 296
 297         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 298
 299         drm_warn_on_modeset_not_all_locked(dev);
 300
 301         saved_enabled = crtc->enabled;
 302         crtc->enabled = drm_helper_crtc_in_use(crtc);
 303         if (!crtc->enabled)
 304                 return true;
 305
 306         adjusted_mode = drm_mode_duplicate(dev, mode);
 307         if (!adjusted_mode) {
 308                 crtc->enabled = saved_enabled;
 309                 return false;
 310         }
 311
 312         drm_mode_init(&saved_mode, &crtc->mode);
 313         drm_mode_init(&saved_hwmode, &crtc->hwmode);
 314         saved_x = crtc->x;
 315         saved_y = crtc->y;
 316
 317         /* Update crtc values up front so the driver can rely on them for mode
 318          * setting.
 319          */
 320         drm_mode_copy(&crtc->mode, mode);
 321         crtc->x = x;
 322         crtc->y = y;
 323
 324         /* Pass our mode to the connectors and the CRTC to give them a chance to
 325          * adjust it according to limitations or connector properties, and also
 326          * a chance to reject the mode entirely.
 327          */
 328         drm_for_each_encoder(encoder, dev) {
 329
 330                 if (encoder->crtc != crtc)
 331                         continue;
 332
 333                 encoder_funcs = encoder->helper_private;
 334                 if (!encoder_funcs)
 335                         continue;
 336
 337                 encoder_funcs = encoder->helper_private;
 338                 if (encoder_funcs->mode_fixup) {
 339                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 340                                                               adjusted_mode))) {
 341                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 342                                 goto done;
 343                         }
 344                 }
 345         }
 346
 347         if (crtc_funcs->mode_fixup) {
 348                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 349                                                 adjusted_mode))) {
 350                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 351                         goto done;
 352                 }
 353         }
 354         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 355
 356         drm_mode_copy(&crtc->hwmode, adjusted_mode);
 357
 358         /* Prepare the encoders and CRTCs before setting the mode. */
 359         drm_for_each_encoder(encoder, dev) {
 360
 361                 if (encoder->crtc != crtc)
 362                         continue;
 363
 364                 encoder_funcs = encoder->helper_private;
 365                 if (!encoder_funcs)
 366                         continue;
 367
 368                 /* Disable the encoders as the first thing we do. */
 369                 if (encoder_funcs->prepare)
 370                         encoder_funcs->prepare(encoder);
 371         }
 372
 373         drm_crtc_prepare_encoders(dev);
 374
 375         crtc_funcs->prepare(crtc);
 376
 377         /* Set up the DPLL and any encoders state that needs to adjust or depend
 378          * on the DPLL.
 379          */
 380         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 381         if (!ret)
 382             goto done;
 383
 384         drm_for_each_encoder(encoder, dev) {
 385
 386                 if (encoder->crtc != crtc)
 387                         continue;
 388
 389                 encoder_funcs = encoder->helper_private;
 390                 if (!encoder_funcs)
 391                         continue;
 392
 393                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 394                         encoder->base.id, encoder->name, mode->name);
 395                 if (encoder_funcs->mode_set)
 396                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 397         }
 398
 399         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 400         crtc_funcs->commit(crtc);
 401
 402         drm_for_each_encoder(encoder, dev) {
 403
 404                 if (encoder->crtc != crtc)
 405                         continue;
 406
 407                 encoder_funcs = encoder->helper_private;
 408                 if (!encoder_funcs)
 409                         continue;
 410
 411                 if (encoder_funcs->commit)
 412                         encoder_funcs->commit(encoder);
 413         }
 414
 415         /* Calculate and store various constants which
 416          * are later needed by vblank and swap-completion
 417          * timestamping. They are derived from true hwmode.
 418          */
 419         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 420
 421         /* FIXME: add subpixel order */
 422 done:
 423         drm_mode_destroy(dev, adjusted_mode);
 424         if (!ret) {
 425                 crtc->enabled = saved_enabled;
 426                 drm_mode_copy(&crtc->mode, &saved_mode);
 427                 drm_mode_copy(&crtc->hwmode, &saved_hwmode);
 428                 crtc->x = saved_x;
 429                 crtc->y = saved_y;
 430         }
 431
 432         return ret;
 433 }
 434 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 435
 436 /**
 437  * drm_crtc_helper_atomic_check() - Helper to check CRTC atomic-state
 438  * @crtc: CRTC to check
 439  * @state: atomic state object
 440  *
 441  * Provides a default CRTC-state check handler for CRTCs that only have
 442  * one primary plane attached to it.
 443  *
 444  * This is often the case for the CRTC of simple framebuffers. See also
 445  * drm_plane_helper_atomic_check() for the respective plane-state check
 446  * helper function.
 447  *
 448  * RETURNS:
 449  * Zero on success, or an errno code otherwise.
 450  */
 451 int drm_crtc_helper_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
 452 {
 453         struct drm_crtc_state *new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 454
 455         if (!new_crtc_state->enable)
 456                 return 0;
 457
 458         return drm_atomic_helper_check_crtc_primary_plane(new_crtc_state);
 459 }
 460 EXPORT_SYMBOL(drm_crtc_helper_atomic_check);
 461
 462 static void
 463 drm_crtc_helper_disable(struct drm_crtc *crtc)
 464 {
 465         struct drm_device *dev = crtc->dev;
 466         struct drm_connector *connector;
 467         struct drm_encoder *encoder;
 468
 469         /* Decouple all encoders and their attached connectors from this crtc */
 470         drm_for_each_encoder(encoder, dev) {
 471                 struct drm_connector_list_iter conn_iter;
 472
 473                 if (encoder->crtc != crtc)
 474                         continue;
 475
 476                 drm_connector_list_iter_begin(dev, &conn_iter);
 477                 drm_for_each_connector_iter(connector, &conn_iter) {
 478                         if (connector->encoder != encoder)
 479                                 continue;
 480
 481                         connector->encoder = NULL;
 482
 483                         /*
 484                          * drm_helper_disable_unused_functions() ought to be
 485                          * doing this, but since we've decoupled the encoder
 486                          * from the connector above, the required connection
 487                          * between them is henceforth no longer available.
 488                          */
 489                         connector->dpms = DRM_MODE_DPMS_OFF;
 490
 491                         /* we keep a reference while the encoder is bound */
 492                         drm_connector_put(connector);
 493                 }
 494                 drm_connector_list_iter_end(&conn_iter);
 495         }
 496
 497         __drm_helper_disable_unused_functions(dev);
 498 }
 499
 500 /*
 501  * For connectors that support multiple encoders, either the
 502  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
 503  */
 504 struct drm_encoder *
 505 drm_connector_get_single_encoder(struct drm_connector *connector)
 506 {
 507         struct drm_encoder *encoder;
 508
 509         WARN_ON(hweight32(connector->possible_encoders) > 1);
 510         drm_connector_for_each_possible_encoder(connector, encoder)
 511                 return encoder;
 512
 513         return NULL;
 514 }
 515
 516 /**
 517  * drm_crtc_helper_set_config - set a new config from userspace
 518  * @set: mode set configuration
 519  * @ctx: lock acquire context, not used here
 520  *
 521  * The drm_crtc_helper_set_config() helper function implements the of
 522  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
 523  * helpers.
 524  *
 525  * It first tries to locate the best encoder for each connector by calling the
 526  * connector @drm_connector_helper_funcs.best_encoder helper operation.
 527  *
 528  * After locating the appropriate encoders, the helper function will call the
 529  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
 530  * or reject it completely in which case an error will be returned to the
 531  * application. If the new configuration after mode adjustment is identical to
 532  * the current configuration the helper function will return without performing
 533  * any other operation.
 534  *
 535  * If the adjusted mode is identical to the current mode but changes to the
 536  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
 537  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
 538  *
 539  * If the adjusted mode differs from the current mode, or if the
 540  * ->mode_set_base() helper operation is not provided, the helper function
 541  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
 542  * and ->commit() CRTC and encoder helper operations, in that order.
 543  * Alternatively it can also use the dpms and disable helper operations. For
 544  * details see &struct drm_crtc_helper_funcs and struct
 545  * &drm_encoder_helper_funcs.
 546  *
 547  * This function is deprecated.  New drivers must implement atomic modeset
 548  * support, for which this function is unsuitable. Instead drivers should use
 549  * drm_atomic_helper_set_config().
 550  *
 551  * Returns:
 552  * Returns 0 on success, negative errno numbers on failure.
 553  */
 554 int drm_crtc_helper_set_config(struct drm_mode_set *set,
 555                                struct drm_modeset_acquire_ctx *ctx)
 556 {
 557         struct drm_device *dev;
 558         struct drm_crtc **save_encoder_crtcs, *new_crtc;
 559         struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
 560         bool mode_changed = false; /* if true do a full mode set */
 561         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 562         struct drm_connector *connector;
 563         struct drm_connector_list_iter conn_iter;
 564         int count = 0, ro, fail = 0;
 565         const struct drm_crtc_helper_funcs *crtc_funcs;
 566         struct drm_mode_set save_set;
 567         int ret;
 568         int i;
 569
 570         DRM_DEBUG_KMS("\n");
 571
 572         BUG_ON(!set);
 573         BUG_ON(!set->crtc);
 574         BUG_ON(!set->crtc->helper_private);
 575
 576         /* Enforce sane interface api - has been abused by the fb helper. */
 577         BUG_ON(!set->mode && set->fb);
 578         BUG_ON(set->fb && set->num_connectors == 0);
 579
 580         crtc_funcs = set->crtc->helper_private;
 581
 582         dev = set->crtc->dev;
 583         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 584
 585         if (!set->mode)
 586                 set->fb = NULL;
 587
 588         if (set->fb) {
 589                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 590                               set->crtc->base.id, set->crtc->name,
 591                               set->fb->base.id,
 592                               (int)set->num_connectors, set->x, set->y);
 593         } else {
 594                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 595                               set->crtc->base.id, set->crtc->name);
 596                 drm_crtc_helper_disable(set->crtc);
 597                 return 0;
 598         }
 599
 600         drm_warn_on_modeset_not_all_locked(dev);
 601
 602         /*
 603          * Allocate space for the backup of all (non-pointer) encoder and
 604          * connector data.
 605          */
 606         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 607                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 608         if (!save_encoder_crtcs)
 609                 return -ENOMEM;
 610
 611         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 612                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 613         if (!save_connector_encoders) {
 614                 kfree(save_encoder_crtcs);
 615                 return -ENOMEM;
 616         }
 617
 618         /*
 619          * Copy data. Note that driver private data is not affected.
 620          * Should anything bad happen only the expected state is
 621          * restored, not the drivers personal bookkeeping.
 622          */
 623         count = 0;
 624         drm_for_each_encoder(encoder, dev) {
 625                 save_encoder_crtcs[count++] = encoder->crtc;
 626         }
 627
 628         count = 0;
 629         drm_connector_list_iter_begin(dev, &conn_iter);
 630         drm_for_each_connector_iter(connector, &conn_iter)
 631                 save_connector_encoders[count++] = connector->encoder;
 632         drm_connector_list_iter_end(&conn_iter);
 633
 634         save_set.crtc = set->crtc;
 635         save_set.mode = &set->crtc->mode;
 636         save_set.x = set->crtc->x;
 637         save_set.y = set->crtc->y;
 638         save_set.fb = set->crtc->primary->fb;
 639
 640         /* We should be able to check here if the fb has the same properties
 641          * and then just flip_or_move it */
 642         if (set->crtc->primary->fb != set->fb) {
 643                 /* If we have no fb then treat it as a full mode set */
 644                 if (set->crtc->primary->fb == NULL) {
 645                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 646                         mode_changed = true;
 647                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 648                         mode_changed = true;
 649                 } else
 650                         fb_changed = true;
 651         }
 652
 653         if (set->x != set->crtc->x || set->y != set->crtc->y)
 654                 fb_changed = true;
 655
 656         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 657                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 658                 drm_mode_debug_printmodeline(&set->crtc->mode);
 659                 drm_mode_debug_printmodeline(set->mode);
 660                 mode_changed = true;
 661         }
 662
 663         /* take a reference on all unbound connectors in set, reuse the
 664          * already taken reference for bound connectors
 665          */
 666         for (ro = 0; ro < set->num_connectors; ro++) {
 667                 if (set->connectors[ro]->encoder)
 668                         continue;
 669                 drm_connector_get(set->connectors[ro]);
 670         }
 671
 672         /* a) traverse passed in connector list and get encoders for them */
 673         count = 0;
 674         drm_connector_list_iter_begin(dev, &conn_iter);
 675         drm_for_each_connector_iter(connector, &conn_iter) {
 676                 const struct drm_connector_helper_funcs *connector_funcs =
 677                         connector->helper_private;
 678                 new_encoder = connector->encoder;
 679                 for (ro = 0; ro < set->num_connectors; ro++) {
 680                         if (set->connectors[ro] == connector) {
 681                                 if (connector_funcs->best_encoder)
 682                                         new_encoder = connector_funcs->best_encoder(connector);
 683                                 else
 684                                         new_encoder = drm_connector_get_single_encoder(connector);
 685
 686                                 /* if we can't get an encoder for a connector
 687                                    we are setting now - then fail */
 688                                 if (new_encoder == NULL)
 689                                         /* don't break so fail path works correct */
 690                                         fail = 1;
 691
 692                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 693                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 694                                         mode_changed = true;
 695                                 }
 696
 697                                 break;
 698                         }
 699                 }
 700
 701                 if (new_encoder != connector->encoder) {
 702                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 703                         mode_changed = true;
 704                         /* If the encoder is reused for another connector, then
 705                          * the appropriate crtc will be set later.
 706                          */
 707                         if (connector->encoder)
 708                                 connector->encoder->crtc = NULL;
 709                         connector->encoder = new_encoder;
 710                 }
 711         }
 712         drm_connector_list_iter_end(&conn_iter);
 713
 714         if (fail) {
 715                 ret = -EINVAL;
 716                 goto fail;
 717         }
 718
 719         count = 0;
 720         drm_connector_list_iter_begin(dev, &conn_iter);
 721         drm_for_each_connector_iter(connector, &conn_iter) {
 722                 if (!connector->encoder)
 723                         continue;
 724
 725                 if (connector->encoder->crtc == set->crtc)
 726                         new_crtc = NULL;
 727                 else
 728                         new_crtc = connector->encoder->crtc;
 729
 730                 for (ro = 0; ro < set->num_connectors; ro++) {
 731                         if (set->connectors[ro] == connector)
 732                                 new_crtc = set->crtc;
 733                 }
 734
 735                 /* Make sure the new CRTC will work with the encoder */
 736                 if (new_crtc &&
 737                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 738                         ret = -EINVAL;
 739                         drm_connector_list_iter_end(&conn_iter);
 740                         goto fail;
 741                 }
 742                 if (new_crtc != connector->encoder->crtc) {
 743                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 744                         mode_changed = true;
 745                         connector->encoder->crtc = new_crtc;
 746                 }
 747                 if (new_crtc) {
 748                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
 749                                       connector->base.id, connector->name,
 750                                       new_crtc->base.id, new_crtc->name);
 751                 } else {
 752                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 753                                       connector->base.id, connector->name);
 754                 }
 755         }
 756         drm_connector_list_iter_end(&conn_iter);
 757
 758         /* mode_set_base is not a required function */
 759         if (fb_changed && !crtc_funcs->mode_set_base)
 760                 mode_changed = true;
 761
 762         if (mode_changed) {
 763                 if (drm_helper_crtc_in_use(set->crtc)) {
 764                         DRM_DEBUG_KMS("attempting to set mode from"
 765                                         " userspace\n");
 766                         drm_mode_debug_printmodeline(set->mode);
 767                         set->crtc->primary->fb = set->fb;
 768                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 769                                                       set->x, set->y,
 770                                                       save_set.fb)) {
 771                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
 772                                           set->crtc->base.id, set->crtc->name);
 773                                 set->crtc->primary->fb = save_set.fb;
 774                                 ret = -EINVAL;
 775                                 goto fail;
 776                         }
 777                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 778                         for (i = 0; i < set->num_connectors; i++) {
 779                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 780                                               set->connectors[i]->name);
 781                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 782                         }
 783                 }
 784                 __drm_helper_disable_unused_functions(dev);
 785         } else if (fb_changed) {
 786                 set->crtc->x = set->x;
 787                 set->crtc->y = set->y;
 788                 set->crtc->primary->fb = set->fb;
 789                 ret = crtc_funcs->mode_set_base(set->crtc,
 790                                                 set->x, set->y, save_set.fb);
 791                 if (ret != 0) {
 792                         set->crtc->x = save_set.x;
 793                         set->crtc->y = save_set.y;
 794                         set->crtc->primary->fb = save_set.fb;
 795                         goto fail;
 796                 }
 797         }
 798
 799         kfree(save_connector_encoders);
 800         kfree(save_encoder_crtcs);
 801         return 0;
 802
 803 fail:
 804         /* Restore all previous data. */
 805         count = 0;
 806         drm_for_each_encoder(encoder, dev) {
 807                 encoder->crtc = save_encoder_crtcs[count++];
 808         }
 809
 810         count = 0;
 811         drm_connector_list_iter_begin(dev, &conn_iter);
 812         drm_for_each_connector_iter(connector, &conn_iter)
 813                 connector->encoder = save_connector_encoders[count++];
 814         drm_connector_list_iter_end(&conn_iter);
 815
 816         /* after fail drop reference on all unbound connectors in set, let
 817          * bound connectors keep their reference
 818          */
 819         for (ro = 0; ro < set->num_connectors; ro++) {
 820                 if (set->connectors[ro]->encoder)
 821                         continue;
 822                 drm_connector_put(set->connectors[ro]);
 823         }
 824
 825         /* Try to restore the config */
 826         if (mode_changed &&
 827             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 828                                       save_set.y, save_set.fb))
 829                 DRM_ERROR("failed to restore config after modeset failure\n");
 830
 831         kfree(save_connector_encoders);
 832         kfree(save_encoder_crtcs);
 833         return ret;
 834 }
 835 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 836
 837 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 838 {
 839         int dpms = DRM_MODE_DPMS_OFF;
 840         struct drm_connector *connector;
 841         struct drm_connector_list_iter conn_iter;
 842         struct drm_device *dev = encoder->dev;
 843
 844         drm_connector_list_iter_begin(dev, &conn_iter);
 845         drm_for_each_connector_iter(connector, &conn_iter)
 846                 if (connector->encoder == encoder)
 847                         if (connector->dpms < dpms)
 848                                 dpms = connector->dpms;
 849         drm_connector_list_iter_end(&conn_iter);
 850
 851         return dpms;
 852 }
 853
 854 /* Helper which handles bridge ordering around encoder dpms */
 855 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 856 {
 857         const struct drm_encoder_helper_funcs *encoder_funcs;
 858
 859         encoder_funcs = encoder->helper_private;
 860         if (!encoder_funcs)
 861                 return;
 862
 863         if (encoder_funcs->dpms)
 864                 encoder_funcs->dpms(encoder, mode);
 865 }
 866
 867 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 868 {
 869         int dpms = DRM_MODE_DPMS_OFF;
 870         struct drm_connector *connector;
 871         struct drm_connector_list_iter conn_iter;
 872         struct drm_device *dev = crtc->dev;
 873
 874         drm_connector_list_iter_begin(dev, &conn_iter);
 875         drm_for_each_connector_iter(connector, &conn_iter)
 876                 if (connector->encoder && connector->encoder->crtc == crtc)
 877                         if (connector->dpms < dpms)
 878                                 dpms = connector->dpms;
 879         drm_connector_list_iter_end(&conn_iter);
 880
 881         return dpms;
 882 }
 883
 884 /**
 885  * drm_helper_connector_dpms() - connector dpms helper implementation
 886  * @connector: affected connector
 887  * @mode: DPMS mode
 888  *
 889  * The drm_helper_connector_dpms() helper function implements the
 890  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 891  * helpers.
 892  *
 893  * This is the main helper function provided by the CRTC helper framework for
 894  * implementing the DPMS connector attribute. It computes the new desired DPMS
 895  * state for all encoders and CRTCs in the output mesh and calls the
 896  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 897  * provided by the driver.
 898  *
 899  * This function is deprecated.  New drivers must implement atomic modeset
 900  * support, where DPMS is handled in the DRM core.
 901  *
 902  * Returns:
 903  * Always returns 0.
 904  */
 905 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 906 {
 907         struct drm_encoder *encoder = connector->encoder;
 908         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 909         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 910
 911         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 912
 913         if (mode == connector->dpms)
 914                 return 0;
 915
 916         old_dpms = connector->dpms;
 917         connector->dpms = mode;
 918
 919         if (encoder)
 920                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 921
 922         /* from off to on, do crtc then encoder */
 923         if (mode < old_dpms) {
 924                 if (crtc) {
 925                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 926
 927                         if (crtc_funcs->dpms)
 928                                 (*crtc_funcs->dpms) (crtc,
 929                                                      drm_helper_choose_crtc_dpms(crtc));
 930                 }
 931                 if (encoder)
 932                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 933         }
 934
 935         /* from on to off, do encoder then crtc */
 936         if (mode > old_dpms) {
 937                 if (encoder)
 938                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 939                 if (crtc) {
 940                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 941
 942                         if (crtc_funcs->dpms)
 943                                 (*crtc_funcs->dpms) (crtc,
 944                                                      drm_helper_choose_crtc_dpms(crtc));
 945                 }
 946         }
 947
 948         return 0;
 949 }
 950 EXPORT_SYMBOL(drm_helper_connector_dpms);
 951
 952 /**
 953  * drm_helper_resume_force_mode - force-restore mode setting configuration
 954  * @dev: drm_device which should be restored
 955  *
 956  * Drivers which use the mode setting helpers can use this function to
 957  * force-restore the mode setting configuration e.g. on resume or when something
 958  * else might have trampled over the hw state (like some overzealous old BIOSen
 959  * tended to do).
 960  *
 961  * This helper doesn't provide a error return value since restoring the old
 962  * config should never fail due to resource allocation issues since the driver
 963  * has successfully set the restored configuration already. Hence this should
 964  * boil down to the equivalent of a few dpms on calls, which also don't provide
 965  * an error code.
 966  *
 967  * Drivers where simply restoring an old configuration again might fail (e.g.
 968  * due to slight differences in allocating shared resources when the
 969  * configuration is restored in a different order than when userspace set it up)
 970  * need to use their own restore logic.
 971  *
 972  * This function is deprecated. New drivers should implement atomic mode-
 973  * setting and use the atomic suspend/resume helpers.
 974  *
 975  * See also:
 976  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 977  */
 978 void drm_helper_resume_force_mode(struct drm_device *dev)
 979 {
 980         struct drm_crtc *crtc;
 981         struct drm_encoder *encoder;
 982         const struct drm_crtc_helper_funcs *crtc_funcs;
 983         int encoder_dpms;
 984         bool ret;
 985
 986         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 987
 988         drm_modeset_lock_all(dev);
 989         drm_for_each_crtc(crtc, dev) {
 990
 991                 if (!crtc->enabled)
 992                         continue;
 993
 994                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 995                                                crtc->x, crtc->y, crtc->primary->fb);
 996
 997                 /* Restoring the old config should never fail! */
 998                 if (ret == false)
 999                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
1000
1001                 /* Turn off outputs that were already powered off */
1002                 if (drm_helper_choose_crtc_dpms(crtc)) {
1003                         drm_for_each_encoder(encoder, dev) {
1004
1005                                 if(encoder->crtc != crtc)
1006                                         continue;
1007
1008                                 encoder_dpms = drm_helper_choose_encoder_dpms(
1009                                                         encoder);
1010
1011                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
1012                         }
1013
1014                         crtc_funcs = crtc->helper_private;
1015                         if (crtc_funcs->dpms)
1016                                 (*crtc_funcs->dpms) (crtc,
1017                                                      drm_helper_choose_crtc_dpms(crtc));
1018                 }
1019         }
1020
1021         /* disable the unused connectors while restoring the modesetting */
1022         __drm_helper_disable_unused_functions(dev);
1023         drm_modeset_unlock_all(dev);
1024 }
1025 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1026
1027 /**
1028  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
1029  * @dev: DRM device whose CRTCs to turn off
1030  *
1031  * Drivers may want to call this on unload to ensure that all displays are
1032  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
1033  *
1034  * Note: This should only be used by non-atomic legacy drivers. For an atomic
1035  * version look at drm_atomic_helper_shutdown().
1036  *
1037  * Returns:
1038  * Zero on success, error code on failure.
1039  */
1040 int drm_helper_force_disable_all(struct drm_device *dev)
1041 {
1042         struct drm_crtc *crtc;
1043         int ret = 0;
1044
1045         drm_modeset_lock_all(dev);
1046         drm_for_each_crtc(crtc, dev)
1047                 if (crtc->enabled) {
1048                         struct drm_mode_set set = {
1049                                 .crtc = crtc,
1050                         };
1051
1052                         ret = drm_mode_set_config_internal(&set);
1053                         if (ret)
1054                                 goto out;
1055                 }
1056 out:
1057         drm_modeset_unlock_all(dev);
1058         return ret;
1059 }
1060 EXPORT_SYMBOL(drm_helper_force_disable_all);