drivers/gpu/drm/drm_probe_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  * DOC: output probing helper overview
  44  *
  45  * This library provides some helper code for output probing. It provides an
  46  * implementation of the core connector->fill_modes interface with
  47  * drm_helper_probe_single_connector_modes.
  48  *
  49  * It also provides support for polling connectors with a work item and for
  50  * generic hotplug interrupt handling where the driver doesn't or cannot keep
  51  * track of a per-connector hpd interrupt.
  52  *
  53  * This helper library can be used independently of the modeset helper library.
  54  * Drivers can also overwrite different parts e.g. use their own hotplug
  55  * handling code to avoid probing unrelated outputs.
  56  */
  57
  58 static bool drm_kms_helper_poll = true;
  59 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
  60
  61 static enum drm_mode_status
  62 drm_mode_validate_flag(const struct drm_display_mode *mode,
  63                        int flags)
  64 {
  65         if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
  66             !(flags & DRM_MODE_FLAG_INTERLACE))
  67                 return MODE_NO_INTERLACE;
  68
  69         if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
  70             !(flags & DRM_MODE_FLAG_DBLSCAN))
  71                 return MODE_NO_DBLESCAN;
  72
  73         if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
  74             !(flags & DRM_MODE_FLAG_3D_MASK))
  75                 return MODE_NO_STEREO;
  76
  77         return MODE_OK;
  78 }
  79
  80 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
  81 {
  82         struct drm_display_mode *mode;
  83
  84         if (!connector->cmdline_mode.specified)
  85                 return 0;
  86
  87         mode = drm_mode_create_from_cmdline_mode(connector->dev,
  88                                                  &connector->cmdline_mode);
  89         if (mode == NULL)
  90                 return 0;
  91
  92         drm_mode_probed_add(connector, mode);
  93         return 1;
  94 }
  95
  96 static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
  97                                                               uint32_t maxX, uint32_t maxY, bool merge_type_bits)
  98 {
  99         struct drm_device *dev = connector->dev;
 100         struct drm_display_mode *mode;
 101         struct drm_connector_helper_funcs *connector_funcs =
 102                 connector->helper_private;
 103         int count = 0;
 104         int mode_flags = 0;
 105         bool verbose_prune = true;
 106         enum drm_connector_status old_status;
 107
 108         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 109
 110         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
 111                         connector->name);
 112         /* set all modes to the unverified state */
 113         list_for_each_entry(mode, &connector->modes, head)
 114                 mode->status = MODE_UNVERIFIED;
 115
 116         if (connector->force) {
 117                 if (connector->force == DRM_FORCE_ON ||
 118                     connector->force == DRM_FORCE_ON_DIGITAL)
 119                         connector->status = connector_status_connected;
 120                 else
 121                         connector->status = connector_status_disconnected;
 122                 if (connector->funcs->force)
 123                         connector->funcs->force(connector);
 124         } else {
 125                 old_status = connector->status;
 126
 127                 connector->status = connector->funcs->detect(connector, true);
 128
 129                 /*
 130                  * Normally either the driver's hpd code or the poll loop should
 131                  * pick up any changes and fire the hotplug event. But if
 132                  * userspace sneaks in a probe, we might miss a change. Hence
 133                  * check here, and if anything changed start the hotplug code.
 134                  */
 135                 if (old_status != connector->status) {
 136                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
 137                                       connector->base.id,
 138                                       connector->name,
 139                                       old_status, connector->status);
 140
 141                         /*
 142                          * The hotplug event code might call into the fb
 143                          * helpers, and so expects that we do not hold any
 144                          * locks. Fire up the poll struct instead, it will
 145                          * disable itself again.
 146                          */
 147                         dev->mode_config.delayed_event = true;
 148                         if (dev->mode_config.poll_enabled)
 149                                 schedule_delayed_work(&dev->mode_config.output_poll_work,
 150                                                       0);
 151                 }
 152         }
 153
 154         /* Re-enable polling in case the global poll config changed. */
 155         if (drm_kms_helper_poll != dev->mode_config.poll_running)
 156                 drm_kms_helper_poll_enable(dev);
 157
 158         dev->mode_config.poll_running = drm_kms_helper_poll;
 159
 160         if (connector->status == connector_status_disconnected) {
 161                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
 162                         connector->base.id, connector->name);
 163                 drm_mode_connector_update_edid_property(connector, NULL);
 164                 verbose_prune = false;
 165                 goto prune;
 166         }
 167
 168 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
 169         count = drm_load_edid_firmware(connector);
 170         if (count == 0)
 171 #endif
 172         {
 173                 if (connector->override_edid) {
 174                         struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
 175
 176                         count = drm_add_edid_modes(connector, edid);
 177                 } else
 178                         count = (*connector_funcs->get_modes)(connector);
 179         }
 180
 181         if (count == 0 && connector->status == connector_status_connected)
 182                 count = drm_add_modes_noedid(connector, 1024, 768);
 183         count += drm_helper_probe_add_cmdline_mode(connector);
 184         if (count == 0)
 185                 goto prune;
 186
 187         drm_mode_connector_list_update(connector, merge_type_bits);
 188
 189         if (connector->interlace_allowed)
 190                 mode_flags |= DRM_MODE_FLAG_INTERLACE;
 191         if (connector->doublescan_allowed)
 192                 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
 193         if (connector->stereo_allowed)
 194                 mode_flags |= DRM_MODE_FLAG_3D_MASK;
 195
 196         list_for_each_entry(mode, &connector->modes, head) {
 197                 mode->status = drm_mode_validate_basic(mode);
 198
 199                 if (mode->status == MODE_OK)
 200                         mode->status = drm_mode_validate_size(mode, maxX, maxY);
 201
 202                 if (mode->status == MODE_OK)
 203                         mode->status = drm_mode_validate_flag(mode, mode_flags);
 204
 205                 if (mode->status == MODE_OK && connector_funcs->mode_valid)
 206                         mode->status = connector_funcs->mode_valid(connector,
 207                                                                    mode);
 208         }
 209
 210 prune:
 211         drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
 212
 213         if (list_empty(&connector->modes))
 214                 return 0;
 215
 216         list_for_each_entry(mode, &connector->modes, head)
 217                 mode->vrefresh = drm_mode_vrefresh(mode);
 218
 219         drm_mode_sort(&connector->modes);
 220
 221         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
 222                         connector->name);
 223         list_for_each_entry(mode, &connector->modes, head) {
 224                 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 225                 drm_mode_debug_printmodeline(mode);
 226         }
 227
 228         return count;
 229 }
 230
 231 /**
 232  * drm_helper_probe_single_connector_modes - get complete set of display modes
 233  * @connector: connector to probe
 234  * @maxX: max width for modes
 235  * @maxY: max height for modes
 236  *
 237  * Based on the helper callbacks implemented by @connector try to detect all
 238  * valid modes.  Modes will first be added to the connector's probed_modes list,
 239  * then culled (based on validity and the @maxX, @maxY parameters) and put into
 240  * the normal modes list.
 241  *
 242  * Intended to be use as a generic implementation of the ->fill_modes()
 243  * @connector vfunc for drivers that use the crtc helpers for output mode
 244  * filtering and detection.
 245  *
 246  * Returns:
 247  * The number of modes found on @connector.
 248  */
 249 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 250                                             uint32_t maxX, uint32_t maxY)
 251 {
 252         return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
 253 }
 254 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
 255
 256 /**
 257  * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
 258  * @connector: connector to probe
 259  * @maxX: max width for modes
 260  * @maxY: max height for modes
 261  *
 262  * This operates like drm_hehlper_probe_single_connector_modes except it
 263  * replaces the mode bits instead of merging them for preferred modes.
 264  */
 265 int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
 266                                             uint32_t maxX, uint32_t maxY)
 267 {
 268         return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
 269 }
 270 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
 271
 272 /**
 273  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
 274  * @dev: drm_device whose connector state changed
 275  *
 276  * This function fires off the uevent for userspace and also calls the
 277  * output_poll_changed function, which is most commonly used to inform the fbdev
 278  * emulation code and allow it to update the fbcon output configuration.
 279  *
 280  * Drivers should call this from their hotplug handling code when a change is
 281  * detected. Note that this function does not do any output detection of its
 282  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
 283  * driver already.
 284  *
 285  * This function must be called from process context with no mode
 286  * setting locks held.
 287  */
 288 void drm_kms_helper_hotplug_event(struct drm_device *dev)
 289 {
 290         /* send a uevent + call fbdev */
 291         drm_sysfs_hotplug_event(dev);
 292         if (dev->mode_config.funcs->output_poll_changed)
 293                 dev->mode_config.funcs->output_poll_changed(dev);
 294 }
 295 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 296
 297 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
 298 static void output_poll_execute(struct work_struct *work)
 299 {
 300         struct delayed_work *delayed_work = to_delayed_work(work);
 301         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
 302         struct drm_connector *connector;
 303         enum drm_connector_status old_status;
 304         bool repoll = false, changed;
 305
 306         /* Pick up any changes detected by the probe functions. */
 307         changed = dev->mode_config.delayed_event;
 308         dev->mode_config.delayed_event = false;
 309
 310         if (!drm_kms_helper_poll)
 311                 goto out;
 312
 313         mutex_lock(&dev->mode_config.mutex);
 314         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 315
 316                 /* Ignore forced connectors. */
 317                 if (connector->force)
 318                         continue;
 319
 320                 /* Ignore HPD capable connectors and connectors where we don't
 321                  * want any hotplug detection at all for polling. */
 322                 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
 323                         continue;
 324
 325                 repoll = true;
 326
 327                 old_status = connector->status;
 328                 /* if we are connected and don't want to poll for disconnect
 329                    skip it */
 330                 if (old_status == connector_status_connected &&
 331                     !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
 332                         continue;
 333
 334                 connector->status = connector->funcs->detect(connector, false);
 335                 if (old_status != connector->status) {
 336                         const char *old, *new;
 337
 338                         /*
 339                          * The poll work sets force=false when calling detect so
 340                          * that drivers can avoid to do disruptive tests (e.g.
 341                          * when load detect cycles could cause flickering on
 342                          * other, running displays). This bears the risk that we
 343                          * flip-flop between unknown here in the poll work and
 344                          * the real state when userspace forces a full detect
 345                          * call after receiving a hotplug event due to this
 346                          * change.
 347                          *
 348                          * Hence clamp an unknown detect status to the old
 349                          * value.
 350                          */
 351                         if (connector->status == connector_status_unknown) {
 352                                 connector->status = old_status;
 353                                 continue;
 354                         }
 355
 356                         old = drm_get_connector_status_name(old_status);
 357                         new = drm_get_connector_status_name(connector->status);
 358
 359                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
 360                                       "status updated from %s to %s\n",
 361                                       connector->base.id,
 362                                       connector->name,
 363                                       old, new);
 364
 365                         changed = true;
 366                 }
 367         }
 368
 369         mutex_unlock(&dev->mode_config.mutex);
 370
 371 out:
 372         if (changed)
 373                 drm_kms_helper_hotplug_event(dev);
 374
 375         if (repoll)
 376                 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
 377 }
 378
 379 /**
 380  * drm_kms_helper_poll_disable - disable output polling
 381  * @dev: drm_device
 382  *
 383  * This function disables the output polling work.
 384  *
 385  * Drivers can call this helper from their device suspend implementation. It is
 386  * not an error to call this even when output polling isn't enabled or arlready
 387  * disabled.
 388  */
 389 void drm_kms_helper_poll_disable(struct drm_device *dev)
 390 {
 391         if (!dev->mode_config.poll_enabled)
 392                 return;
 393         cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
 394 }
 395 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
 396
 397 /**
 398  * drm_kms_helper_poll_enable - re-enable output polling.
 399  * @dev: drm_device
 400  *
 401  * This function re-enables the output polling work.
 402  *
 403  * Drivers can call this helper from their device resume implementation. It is
 404  * an error to call this when the output polling support has not yet been set
 405  * up.
 406  */
 407 void drm_kms_helper_poll_enable(struct drm_device *dev)
 408 {
 409         bool poll = false;
 410         struct drm_connector *connector;
 411
 412         if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
 413                 return;
 414
 415         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 416                 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
 417                                          DRM_CONNECTOR_POLL_DISCONNECT))
 418                         poll = true;
 419         }
 420
 421         if (poll)
 422                 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
 423 }
 424 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
 425
 426 /**
 427  * drm_kms_helper_poll_init - initialize and enable output polling
 428  * @dev: drm_device
 429  *
 430  * This function intializes and then also enables output polling support for
 431  * @dev. Drivers which do not have reliable hotplug support in hardware can use
 432  * this helper infrastructure to regularly poll such connectors for changes in
 433  * their connection state.
 434  *
 435  * Drivers can control which connectors are polled by setting the
 436  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
 437  * connectors where probing live outputs can result in visual distortion drivers
 438  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
 439  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
 440  * completely ignored by the polling logic.
 441  *
 442  * Note that a connector can be both polled and probed from the hotplug handler,
 443  * in case the hotplug interrupt is known to be unreliable.
 444  */
 445 void drm_kms_helper_poll_init(struct drm_device *dev)
 446 {
 447         INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
 448         dev->mode_config.poll_enabled = true;
 449
 450         drm_kms_helper_poll_enable(dev);
 451 }
 452 EXPORT_SYMBOL(drm_kms_helper_poll_init);
 453
 454 /**
 455  * drm_kms_helper_poll_fini - disable output polling and clean it up
 456  * @dev: drm_device
 457  */
 458 void drm_kms_helper_poll_fini(struct drm_device *dev)
 459 {
 460         drm_kms_helper_poll_disable(dev);
 461 }
 462 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 463
 464 /**
 465  * drm_helper_hpd_irq_event - hotplug processing
 466  * @dev: drm_device
 467  *
 468  * Drivers can use this helper function to run a detect cycle on all connectors
 469  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
 470  * other connectors are ignored, which is useful to avoid reprobing fixed
 471  * panels.
 472  *
 473  * This helper function is useful for drivers which can't or don't track hotplug
 474  * interrupts for each connector.
 475  *
 476  * Drivers which support hotplug interrupts for each connector individually and
 477  * which have a more fine-grained detect logic should bypass this code and
 478  * directly call drm_kms_helper_hotplug_event() in case the connector state
 479  * changed.
 480  *
 481  * This function must be called from process context with no mode
 482  * setting locks held.
 483  *
 484  * Note that a connector can be both polled and probed from the hotplug handler,
 485  * in case the hotplug interrupt is known to be unreliable.
 486  */
 487 bool drm_helper_hpd_irq_event(struct drm_device *dev)
 488 {
 489         struct drm_connector *connector;
 490         enum drm_connector_status old_status;
 491         bool changed = false;
 492
 493         if (!dev->mode_config.poll_enabled)
 494                 return false;
 495
 496         mutex_lock(&dev->mode_config.mutex);
 497         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 498
 499                 /* Only handle HPD capable connectors. */
 500                 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
 501                         continue;
 502
 503                 old_status = connector->status;
 504
 505                 connector->status = connector->funcs->detect(connector, false);
 506                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
 507                               connector->base.id,
 508                               connector->name,
 509                               drm_get_connector_status_name(old_status),
 510                               drm_get_connector_status_name(connector->status));
 511                 if (old_status != connector->status)
 512                         changed = true;
 513         }
 514
 515         mutex_unlock(&dev->mode_config.mutex);
 516
 517         if (changed)
 518                 drm_kms_helper_hotplug_event(dev);
 519
 520         return changed;
 521 }
 522 EXPORT_SYMBOL(drm_helper_hpd_irq_event);