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 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
  97 static void __drm_kms_helper_poll_enable(struct drm_device *dev)
  98 {
  99         bool poll = false;
 100         struct drm_connector *connector;
 101
 102         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 103
 104         if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
 105                 return;
 106
 107         drm_for_each_connector(connector, dev) {
 108                 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
 109                                          DRM_CONNECTOR_POLL_DISCONNECT))
 110                         poll = true;
 111         }
 112
 113         if (poll)
 114                 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
 115 }
 116
 117 static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
 118                                                               uint32_t maxX, uint32_t maxY, bool merge_type_bits)
 119 {
 120         struct drm_device *dev = connector->dev;
 121         struct drm_display_mode *mode;
 122         const struct drm_connector_helper_funcs *connector_funcs =
 123                 connector->helper_private;
 124         int count = 0;
 125         int mode_flags = 0;
 126         bool verbose_prune = true;
 127         enum drm_connector_status old_status;
 128
 129         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 130
 131         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
 132                         connector->name);
 133         /* set all modes to the unverified state */
 134         list_for_each_entry(mode, &connector->modes, head)
 135                 mode->status = MODE_UNVERIFIED;
 136
 137         if (connector->force) {
 138                 if (connector->force == DRM_FORCE_ON ||
 139                     connector->force == DRM_FORCE_ON_DIGITAL)
 140                         connector->status = connector_status_connected;
 141                 else
 142                         connector->status = connector_status_disconnected;
 143                 if (connector->funcs->force)
 144                         connector->funcs->force(connector);
 145         } else {
 146                 old_status = connector->status;
 147
 148                 connector->status = connector->funcs->detect(connector, true);
 149
 150                 /*
 151                  * Normally either the driver's hpd code or the poll loop should
 152                  * pick up any changes and fire the hotplug event. But if
 153                  * userspace sneaks in a probe, we might miss a change. Hence
 154                  * check here, and if anything changed start the hotplug code.
 155                  */
 156                 if (old_status != connector->status) {
 157                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
 158                                       connector->base.id,
 159                                       connector->name,
 160                                       old_status, connector->status);
 161
 162                         /*
 163                          * The hotplug event code might call into the fb
 164                          * helpers, and so expects that we do not hold any
 165                          * locks. Fire up the poll struct instead, it will
 166                          * disable itself again.
 167                          */
 168                         dev->mode_config.delayed_event = true;
 169                         if (dev->mode_config.poll_enabled)
 170                                 schedule_delayed_work(&dev->mode_config.output_poll_work,
 171                                                       0);
 172                 }
 173         }
 174
 175         /* Re-enable polling in case the global poll config changed. */
 176         if (drm_kms_helper_poll != dev->mode_config.poll_running)
 177                 __drm_kms_helper_poll_enable(dev);
 178
 179         dev->mode_config.poll_running = drm_kms_helper_poll;
 180
 181         if (connector->status == connector_status_disconnected) {
 182                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
 183                         connector->base.id, connector->name);
 184                 drm_mode_connector_update_edid_property(connector, NULL);
 185                 verbose_prune = false;
 186                 goto prune;
 187         }
 188
 189 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
 190         count = drm_load_edid_firmware(connector);
 191         if (count == 0)
 192 #endif
 193         {
 194                 if (connector->override_edid) {
 195                         struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
 196
 197                         count = drm_add_edid_modes(connector, edid);
 198                         drm_edid_to_eld(connector, edid);
 199                 } else
 200                         count = (*connector_funcs->get_modes)(connector);
 201         }
 202
 203         if (count == 0 && connector->status == connector_status_connected)
 204                 count = drm_add_modes_noedid(connector, 1024, 768);
 205         count += drm_helper_probe_add_cmdline_mode(connector);
 206         if (count == 0)
 207                 goto prune;
 208
 209         drm_mode_connector_list_update(connector, merge_type_bits);
 210
 211         if (connector->interlace_allowed)
 212                 mode_flags |= DRM_MODE_FLAG_INTERLACE;
 213         if (connector->doublescan_allowed)
 214                 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
 215         if (connector->stereo_allowed)
 216                 mode_flags |= DRM_MODE_FLAG_3D_MASK;
 217
 218         list_for_each_entry(mode, &connector->modes, head) {
 219                 mode->status = drm_mode_validate_basic(mode);
 220
 221                 if (mode->status == MODE_OK)
 222                         mode->status = drm_mode_validate_size(mode, maxX, maxY);
 223
 224                 if (mode->status == MODE_OK)
 225                         mode->status = drm_mode_validate_flag(mode, mode_flags);
 226
 227                 if (mode->status == MODE_OK && connector_funcs->mode_valid)
 228                         mode->status = connector_funcs->mode_valid(connector,
 229                                                                    mode);
 230         }
 231
 232 prune:
 233         drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
 234
 235         if (list_empty(&connector->modes))
 236                 return 0;
 237
 238         list_for_each_entry(mode, &connector->modes, head)
 239                 mode->vrefresh = drm_mode_vrefresh(mode);
 240
 241         drm_mode_sort(&connector->modes);
 242
 243         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
 244                         connector->name);
 245         list_for_each_entry(mode, &connector->modes, head) {
 246                 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 247                 drm_mode_debug_printmodeline(mode);
 248         }
 249
 250         return count;
 251 }
 252
 253 /**
 254  * drm_helper_probe_single_connector_modes - get complete set of display modes
 255  * @connector: connector to probe
 256  * @maxX: max width for modes
 257  * @maxY: max height for modes
 258  *
 259  * Based on the helper callbacks implemented by @connector try to detect all
 260  * valid modes.  Modes will first be added to the connector's probed_modes list,
 261  * then culled (based on validity and the @maxX, @maxY parameters) and put into
 262  * the normal modes list.
 263  *
 264  * Intended to be use as a generic implementation of the ->fill_modes()
 265  * @connector vfunc for drivers that use the crtc helpers for output mode
 266  * filtering and detection.
 267  *
 268  * Returns:
 269  * The number of modes found on @connector.
 270  */
 271 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 272                                             uint32_t maxX, uint32_t maxY)
 273 {
 274         return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
 275 }
 276 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
 277
 278 /**
 279  * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
 280  * @connector: connector to probe
 281  * @maxX: max width for modes
 282  * @maxY: max height for modes
 283  *
 284  * This operates like drm_hehlper_probe_single_connector_modes except it
 285  * replaces the mode bits instead of merging them for preferred modes.
 286  */
 287 int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
 288                                             uint32_t maxX, uint32_t maxY)
 289 {
 290         return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
 291 }
 292 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
 293
 294 /**
 295  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
 296  * @dev: drm_device whose connector state changed
 297  *
 298  * This function fires off the uevent for userspace and also calls the
 299  * output_poll_changed function, which is most commonly used to inform the fbdev
 300  * emulation code and allow it to update the fbcon output configuration.
 301  *
 302  * Drivers should call this from their hotplug handling code when a change is
 303  * detected. Note that this function does not do any output detection of its
 304  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
 305  * driver already.
 306  *
 307  * This function must be called from process context with no mode
 308  * setting locks held.
 309  */
 310 void drm_kms_helper_hotplug_event(struct drm_device *dev)
 311 {
 312         /* send a uevent + call fbdev */
 313         drm_sysfs_hotplug_event(dev);
 314         if (dev->mode_config.funcs->output_poll_changed)
 315                 dev->mode_config.funcs->output_poll_changed(dev);
 316 }
 317 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 318
 319 static void output_poll_execute(struct work_struct *work)
 320 {
 321         struct delayed_work *delayed_work = to_delayed_work(work);
 322         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
 323         struct drm_connector *connector;
 324         enum drm_connector_status old_status;
 325         bool repoll = false, changed;
 326
 327         /* Pick up any changes detected by the probe functions. */
 328         changed = dev->mode_config.delayed_event;
 329         dev->mode_config.delayed_event = false;
 330
 331         if (!drm_kms_helper_poll)
 332                 goto out;
 333
 334         mutex_lock(&dev->mode_config.mutex);
 335         drm_for_each_connector(connector, dev) {
 336
 337                 /* Ignore forced connectors. */
 338                 if (connector->force)
 339                         continue;
 340
 341                 /* Ignore HPD capable connectors and connectors where we don't
 342                  * want any hotplug detection at all for polling. */
 343                 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
 344                         continue;
 345
 346                 old_status = connector->status;
 347                 /* if we are connected and don't want to poll for disconnect
 348                    skip it */
 349                 if (old_status == connector_status_connected &&
 350                     !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
 351                         continue;
 352
 353                 repoll = true;
 354
 355                 connector->status = connector->funcs->detect(connector, false);
 356                 if (old_status != connector->status) {
 357                         const char *old, *new;
 358
 359                         /*
 360                          * The poll work sets force=false when calling detect so
 361                          * that drivers can avoid to do disruptive tests (e.g.
 362                          * when load detect cycles could cause flickering on
 363                          * other, running displays). This bears the risk that we
 364                          * flip-flop between unknown here in the poll work and
 365                          * the real state when userspace forces a full detect
 366                          * call after receiving a hotplug event due to this
 367                          * change.
 368                          *
 369                          * Hence clamp an unknown detect status to the old
 370                          * value.
 371                          */
 372                         if (connector->status == connector_status_unknown) {
 373                                 connector->status = old_status;
 374                                 continue;
 375                         }
 376
 377                         old = drm_get_connector_status_name(old_status);
 378                         new = drm_get_connector_status_name(connector->status);
 379
 380                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
 381                                       "status updated from %s to %s\n",
 382                                       connector->base.id,
 383                                       connector->name,
 384                                       old, new);
 385
 386                         changed = true;
 387                 }
 388         }
 389
 390         mutex_unlock(&dev->mode_config.mutex);
 391
 392 out:
 393         if (changed)
 394                 drm_kms_helper_hotplug_event(dev);
 395
 396         if (repoll)
 397                 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
 398 }
 399
 400 /**
 401  * drm_kms_helper_poll_disable - disable output polling
 402  * @dev: drm_device
 403  *
 404  * This function disables the output polling work.
 405  *
 406  * Drivers can call this helper from their device suspend implementation. It is
 407  * not an error to call this even when output polling isn't enabled or arlready
 408  * disabled.
 409  */
 410 void drm_kms_helper_poll_disable(struct drm_device *dev)
 411 {
 412         if (!dev->mode_config.poll_enabled)
 413                 return;
 414         cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
 415 }
 416 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
 417
 418 /**
 419  * drm_kms_helper_poll_enable - re-enable output polling.
 420  * @dev: drm_device
 421  *
 422  * This function re-enables the output polling work.
 423  *
 424  * Drivers can call this helper from their device resume implementation. It is
 425  * an error to call this when the output polling support has not yet been set
 426  * up.
 427  */
 428 void drm_kms_helper_poll_enable(struct drm_device *dev)
 429 {
 430         mutex_lock(&dev->mode_config.mutex);
 431         __drm_kms_helper_poll_enable(dev);
 432         mutex_unlock(&dev->mode_config.mutex);
 433 }
 434 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
 435
 436 /**
 437  * drm_kms_helper_poll_init - initialize and enable output polling
 438  * @dev: drm_device
 439  *
 440  * This function intializes and then also enables output polling support for
 441  * @dev. Drivers which do not have reliable hotplug support in hardware can use
 442  * this helper infrastructure to regularly poll such connectors for changes in
 443  * their connection state.
 444  *
 445  * Drivers can control which connectors are polled by setting the
 446  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
 447  * connectors where probing live outputs can result in visual distortion drivers
 448  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
 449  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
 450  * completely ignored by the polling logic.
 451  *
 452  * Note that a connector can be both polled and probed from the hotplug handler,
 453  * in case the hotplug interrupt is known to be unreliable.
 454  */
 455 void drm_kms_helper_poll_init(struct drm_device *dev)
 456 {
 457         INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
 458         dev->mode_config.poll_enabled = true;
 459
 460         drm_kms_helper_poll_enable(dev);
 461 }
 462 EXPORT_SYMBOL(drm_kms_helper_poll_init);
 463
 464 /**
 465  * drm_kms_helper_poll_fini - disable output polling and clean it up
 466  * @dev: drm_device
 467  */
 468 void drm_kms_helper_poll_fini(struct drm_device *dev)
 469 {
 470         drm_kms_helper_poll_disable(dev);
 471 }
 472 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 473
 474 /**
 475  * drm_helper_hpd_irq_event - hotplug processing
 476  * @dev: drm_device
 477  *
 478  * Drivers can use this helper function to run a detect cycle on all connectors
 479  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
 480  * other connectors are ignored, which is useful to avoid reprobing fixed
 481  * panels.
 482  *
 483  * This helper function is useful for drivers which can't or don't track hotplug
 484  * interrupts for each connector.
 485  *
 486  * Drivers which support hotplug interrupts for each connector individually and
 487  * which have a more fine-grained detect logic should bypass this code and
 488  * directly call drm_kms_helper_hotplug_event() in case the connector state
 489  * changed.
 490  *
 491  * This function must be called from process context with no mode
 492  * setting locks held.
 493  *
 494  * Note that a connector can be both polled and probed from the hotplug handler,
 495  * in case the hotplug interrupt is known to be unreliable.
 496  */
 497 bool drm_helper_hpd_irq_event(struct drm_device *dev)
 498 {
 499         struct drm_connector *connector;
 500         enum drm_connector_status old_status;
 501         bool changed = false;
 502
 503         if (!dev->mode_config.poll_enabled)
 504                 return false;
 505
 506         mutex_lock(&dev->mode_config.mutex);
 507         drm_for_each_connector(connector, dev) {
 508
 509                 /* Only handle HPD capable connectors. */
 510                 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
 511                         continue;
 512
 513                 old_status = connector->status;
 514
 515                 connector->status = connector->funcs->detect(connector, false);
 516                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
 517                               connector->base.id,
 518                               connector->name,
 519                               drm_get_connector_status_name(old_status),
 520                               drm_get_connector_status_name(connector->status));
 521                 if (old_status != connector->status)
 522                         changed = true;
 523         }
 524
 525         mutex_unlock(&dev->mode_config.mutex);
 526
 527         if (changed)
 528                 drm_kms_helper_hotplug_event(dev);
 529
 530         return changed;
 531 }
 532 EXPORT_SYMBOL(drm_helper_hpd_irq_event);