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 &drm_connector_funcs.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 * The probe helpers share the function table structures with other display 58 * helper libraries. See &struct drm_connector_helper_funcs for the details. 59 */ 60 61 static bool drm_kms_helper_poll = true; 62 module_param_named(poll, drm_kms_helper_poll, bool, 0600); 63 64 static enum drm_mode_status 65 drm_mode_validate_flag(const struct drm_display_mode *mode, 66 int flags) 67 { 68 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) && 69 !(flags & DRM_MODE_FLAG_INTERLACE)) 70 return MODE_NO_INTERLACE; 71 72 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) && 73 !(flags & DRM_MODE_FLAG_DBLSCAN)) 74 return MODE_NO_DBLESCAN; 75 76 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) && 77 !(flags & DRM_MODE_FLAG_3D_MASK)) 78 return MODE_NO_STEREO; 79 80 return MODE_OK; 81 } 82 83 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) 84 { 85 struct drm_cmdline_mode *cmdline_mode; 86 struct drm_display_mode *mode; 87 88 cmdline_mode = &connector->cmdline_mode; 89 if (!cmdline_mode->specified) 90 return 0; 91 92 /* Only add a GTF mode if we find no matching probed modes */ 93 list_for_each_entry(mode, &connector->probed_modes, head) { 94 if (mode->hdisplay != cmdline_mode->xres || 95 mode->vdisplay != cmdline_mode->yres) 96 continue; 97 98 if (cmdline_mode->refresh_specified) { 99 /* The probed mode's vrefresh is set until later */ 100 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh) 101 continue; 102 } 103 104 return 0; 105 } 106 107 mode = drm_mode_create_from_cmdline_mode(connector->dev, 108 cmdline_mode); 109 if (mode == NULL) 110 return 0; 111 112 drm_mode_probed_add(connector, mode); 113 return 1; 114 } 115 116 #define DRM_OUTPUT_POLL_PERIOD (10*HZ) 117 /** 118 * drm_kms_helper_poll_enable - re-enable output polling. 119 * @dev: drm_device 120 * 121 * This function re-enables the output polling work, after it has been 122 * temporarily disabled using drm_kms_helper_poll_disable(), for example over 123 * suspend/resume. 124 * 125 * Drivers can call this helper from their device resume implementation. It is 126 * an error to call this when the output polling support has not yet been set 127 * up. 128 * 129 * Note that calls to enable and disable polling must be strictly ordered, which 130 * is automatically the case when they're only call from suspend/resume 131 * callbacks. 132 */ 133 void drm_kms_helper_poll_enable(struct drm_device *dev) 134 { 135 bool poll = false; 136 struct drm_connector *connector; 137 struct drm_connector_list_iter conn_iter; 138 unsigned long delay = DRM_OUTPUT_POLL_PERIOD; 139 140 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll) 141 return; 142 143 drm_connector_list_iter_get(dev, &conn_iter); 144 drm_for_each_connector_iter(connector, &conn_iter) { 145 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | 146 DRM_CONNECTOR_POLL_DISCONNECT)) 147 poll = true; 148 } 149 drm_connector_list_iter_put(&conn_iter); 150 151 if (dev->mode_config.delayed_event) { 152 /* 153 * FIXME: 154 * 155 * Use short (1s) delay to handle the initial delayed event. 156 * This delay should not be needed, but Optimus/nouveau will 157 * fail in a mysterious way if the delayed event is handled as 158 * soon as possible like it is done in 159 * drm_helper_probe_single_connector_modes() in case the poll 160 * was enabled before. 161 */ 162 poll = true; 163 delay = HZ; 164 } 165 166 if (poll) 167 schedule_delayed_work(&dev->mode_config.output_poll_work, delay); 168 } 169 EXPORT_SYMBOL(drm_kms_helper_poll_enable); 170 171 static enum drm_connector_status 172 drm_connector_detect(struct drm_connector *connector, bool force) 173 { 174 return connector->funcs->detect ? 175 connector->funcs->detect(connector, force) : 176 connector_status_connected; 177 } 178 179 /** 180 * drm_helper_probe_single_connector_modes - get complete set of display modes 181 * @connector: connector to probe 182 * @maxX: max width for modes 183 * @maxY: max height for modes 184 * 185 * Based on the helper callbacks implemented by @connector in struct 186 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first 187 * be added to the connector's probed_modes list, then culled (based on validity 188 * and the @maxX, @maxY parameters) and put into the normal modes list. 189 * 190 * Intended to be used as a generic implementation of the 191 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers 192 * for output mode filtering and detection. 193 * 194 * The basic procedure is as follows 195 * 196 * 1. All modes currently on the connector's modes list are marked as stale 197 * 198 * 2. New modes are added to the connector's probed_modes list with 199 * drm_mode_probed_add(). New modes start their life with status as OK. 200 * Modes are added from a single source using the following priority order. 201 * 202 * - debugfs 'override_edid' (used for testing only) 203 * - firmware EDID (drm_load_edid_firmware()) 204 * - &drm_connector_helper_funcs.get_modes vfunc 205 * - if the connector status is connector_status_connected, standard 206 * VESA DMT modes up to 1024x768 are automatically added 207 * (drm_add_modes_noedid()) 208 * 209 * Finally modes specified via the kernel command line (video=...) are 210 * added in addition to what the earlier probes produced 211 * (drm_helper_probe_add_cmdline_mode()). These modes are generated 212 * using the VESA GTF/CVT formulas. 213 * 214 * 3. Modes are moved from the probed_modes list to the modes list. Potential 215 * duplicates are merged together (see drm_mode_connector_list_update()). 216 * After this step the probed_modes list will be empty again. 217 * 218 * 4. Any non-stale mode on the modes list then undergoes validation 219 * 220 * - drm_mode_validate_basic() performs basic sanity checks 221 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY 222 * (if specified) 223 * - drm_mode_validate_flag() checks the modes against basic connector 224 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) 225 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform 226 * driver and/or hardware specific checks 227 * 228 * 5. Any mode whose status is not OK is pruned from the connector's modes list, 229 * accompanied by a debug message indicating the reason for the mode's 230 * rejection (see drm_mode_prune_invalid()). 231 * 232 * Returns: 233 * The number of modes found on @connector. 234 */ 235 int drm_helper_probe_single_connector_modes(struct drm_connector *connector, 236 uint32_t maxX, uint32_t maxY) 237 { 238 struct drm_device *dev = connector->dev; 239 struct drm_display_mode *mode; 240 const struct drm_connector_helper_funcs *connector_funcs = 241 connector->helper_private; 242 int count = 0; 243 int mode_flags = 0; 244 bool verbose_prune = true; 245 enum drm_connector_status old_status; 246 247 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); 248 249 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, 250 connector->name); 251 /* set all old modes to the stale state */ 252 list_for_each_entry(mode, &connector->modes, head) 253 mode->status = MODE_STALE; 254 255 old_status = connector->status; 256 257 if (connector->force) { 258 if (connector->force == DRM_FORCE_ON || 259 connector->force == DRM_FORCE_ON_DIGITAL) 260 connector->status = connector_status_connected; 261 else 262 connector->status = connector_status_disconnected; 263 if (connector->funcs->force) 264 connector->funcs->force(connector); 265 } else { 266 connector->status = drm_connector_detect(connector, true); 267 } 268 269 /* 270 * Normally either the driver's hpd code or the poll loop should 271 * pick up any changes and fire the hotplug event. But if 272 * userspace sneaks in a probe, we might miss a change. Hence 273 * check here, and if anything changed start the hotplug code. 274 */ 275 if (old_status != connector->status) { 276 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", 277 connector->base.id, 278 connector->name, 279 drm_get_connector_status_name(old_status), 280 drm_get_connector_status_name(connector->status)); 281 282 /* 283 * The hotplug event code might call into the fb 284 * helpers, and so expects that we do not hold any 285 * locks. Fire up the poll struct instead, it will 286 * disable itself again. 287 */ 288 dev->mode_config.delayed_event = true; 289 if (dev->mode_config.poll_enabled) 290 schedule_delayed_work(&dev->mode_config.output_poll_work, 291 0); 292 } 293 294 /* Re-enable polling in case the global poll config changed. */ 295 if (drm_kms_helper_poll != dev->mode_config.poll_running) 296 drm_kms_helper_poll_enable(dev); 297 298 dev->mode_config.poll_running = drm_kms_helper_poll; 299 300 if (connector->status == connector_status_disconnected) { 301 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n", 302 connector->base.id, connector->name); 303 drm_mode_connector_update_edid_property(connector, NULL); 304 verbose_prune = false; 305 goto prune; 306 } 307 308 if (connector->override_edid) { 309 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data; 310 311 count = drm_add_edid_modes(connector, edid); 312 drm_edid_to_eld(connector, edid); 313 } else { 314 count = drm_load_edid_firmware(connector); 315 if (count == 0) 316 count = (*connector_funcs->get_modes)(connector); 317 } 318 319 if (count == 0 && connector->status == connector_status_connected) 320 count = drm_add_modes_noedid(connector, 1024, 768); 321 count += drm_helper_probe_add_cmdline_mode(connector); 322 if (count == 0) 323 goto prune; 324 325 drm_mode_connector_list_update(connector); 326 327 if (connector->interlace_allowed) 328 mode_flags |= DRM_MODE_FLAG_INTERLACE; 329 if (connector->doublescan_allowed) 330 mode_flags |= DRM_MODE_FLAG_DBLSCAN; 331 if (connector->stereo_allowed) 332 mode_flags |= DRM_MODE_FLAG_3D_MASK; 333 334 list_for_each_entry(mode, &connector->modes, head) { 335 if (mode->status == MODE_OK) 336 mode->status = drm_mode_validate_basic(mode); 337 338 if (mode->status == MODE_OK) 339 mode->status = drm_mode_validate_size(mode, maxX, maxY); 340 341 if (mode->status == MODE_OK) 342 mode->status = drm_mode_validate_flag(mode, mode_flags); 343 344 if (mode->status == MODE_OK && connector_funcs->mode_valid) 345 mode->status = connector_funcs->mode_valid(connector, 346 mode); 347 } 348 349 prune: 350 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune); 351 352 if (list_empty(&connector->modes)) 353 return 0; 354 355 list_for_each_entry(mode, &connector->modes, head) 356 mode->vrefresh = drm_mode_vrefresh(mode); 357 358 drm_mode_sort(&connector->modes); 359 360 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id, 361 connector->name); 362 list_for_each_entry(mode, &connector->modes, head) { 363 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); 364 drm_mode_debug_printmodeline(mode); 365 } 366 367 return count; 368 } 369 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes); 370 371 /** 372 * drm_kms_helper_hotplug_event - fire off KMS hotplug events 373 * @dev: drm_device whose connector state changed 374 * 375 * This function fires off the uevent for userspace and also calls the 376 * output_poll_changed function, which is most commonly used to inform the fbdev 377 * emulation code and allow it to update the fbcon output configuration. 378 * 379 * Drivers should call this from their hotplug handling code when a change is 380 * detected. Note that this function does not do any output detection of its 381 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the 382 * driver already. 383 * 384 * This function must be called from process context with no mode 385 * setting locks held. 386 */ 387 void drm_kms_helper_hotplug_event(struct drm_device *dev) 388 { 389 /* send a uevent + call fbdev */ 390 drm_sysfs_hotplug_event(dev); 391 if (dev->mode_config.funcs->output_poll_changed) 392 dev->mode_config.funcs->output_poll_changed(dev); 393 } 394 EXPORT_SYMBOL(drm_kms_helper_hotplug_event); 395 396 static void output_poll_execute(struct work_struct *work) 397 { 398 struct delayed_work *delayed_work = to_delayed_work(work); 399 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work); 400 struct drm_connector *connector; 401 struct drm_connector_list_iter conn_iter; 402 enum drm_connector_status old_status; 403 bool repoll = false, changed; 404 405 /* Pick up any changes detected by the probe functions. */ 406 changed = dev->mode_config.delayed_event; 407 dev->mode_config.delayed_event = false; 408 409 if (!drm_kms_helper_poll) 410 goto out; 411 412 if (!mutex_trylock(&dev->mode_config.mutex)) { 413 repoll = true; 414 goto out; 415 } 416 417 drm_connector_list_iter_get(dev, &conn_iter); 418 drm_for_each_connector_iter(connector, &conn_iter) { 419 /* Ignore forced connectors. */ 420 if (connector->force) 421 continue; 422 423 /* Ignore HPD capable connectors and connectors where we don't 424 * want any hotplug detection at all for polling. */ 425 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD) 426 continue; 427 428 old_status = connector->status; 429 /* if we are connected and don't want to poll for disconnect 430 skip it */ 431 if (old_status == connector_status_connected && 432 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT)) 433 continue; 434 435 repoll = true; 436 437 connector->status = drm_connector_detect(connector, false); 438 if (old_status != connector->status) { 439 const char *old, *new; 440 441 /* 442 * The poll work sets force=false when calling detect so 443 * that drivers can avoid to do disruptive tests (e.g. 444 * when load detect cycles could cause flickering on 445 * other, running displays). This bears the risk that we 446 * flip-flop between unknown here in the poll work and 447 * the real state when userspace forces a full detect 448 * call after receiving a hotplug event due to this 449 * change. 450 * 451 * Hence clamp an unknown detect status to the old 452 * value. 453 */ 454 if (connector->status == connector_status_unknown) { 455 connector->status = old_status; 456 continue; 457 } 458 459 old = drm_get_connector_status_name(old_status); 460 new = drm_get_connector_status_name(connector->status); 461 462 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] " 463 "status updated from %s to %s\n", 464 connector->base.id, 465 connector->name, 466 old, new); 467 468 changed = true; 469 } 470 } 471 drm_connector_list_iter_put(&conn_iter); 472 473 mutex_unlock(&dev->mode_config.mutex); 474 475 out: 476 if (changed) 477 drm_kms_helper_hotplug_event(dev); 478 479 if (repoll) 480 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD); 481 } 482 483 /** 484 * drm_kms_helper_poll_disable - disable output polling 485 * @dev: drm_device 486 * 487 * This function disables the output polling work. 488 * 489 * Drivers can call this helper from their device suspend implementation. It is 490 * not an error to call this even when output polling isn't enabled or already 491 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable(). 492 * 493 * Note that calls to enable and disable polling must be strictly ordered, which 494 * is automatically the case when they're only call from suspend/resume 495 * callbacks. 496 */ 497 void drm_kms_helper_poll_disable(struct drm_device *dev) 498 { 499 if (!dev->mode_config.poll_enabled) 500 return; 501 cancel_delayed_work_sync(&dev->mode_config.output_poll_work); 502 } 503 EXPORT_SYMBOL(drm_kms_helper_poll_disable); 504 505 /** 506 * drm_kms_helper_poll_init - initialize and enable output polling 507 * @dev: drm_device 508 * 509 * This function intializes and then also enables output polling support for 510 * @dev. Drivers which do not have reliable hotplug support in hardware can use 511 * this helper infrastructure to regularly poll such connectors for changes in 512 * their connection state. 513 * 514 * Drivers can control which connectors are polled by setting the 515 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On 516 * connectors where probing live outputs can result in visual distortion drivers 517 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this. 518 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are 519 * completely ignored by the polling logic. 520 * 521 * Note that a connector can be both polled and probed from the hotplug handler, 522 * in case the hotplug interrupt is known to be unreliable. 523 */ 524 void drm_kms_helper_poll_init(struct drm_device *dev) 525 { 526 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute); 527 dev->mode_config.poll_enabled = true; 528 529 drm_kms_helper_poll_enable(dev); 530 } 531 EXPORT_SYMBOL(drm_kms_helper_poll_init); 532 533 /** 534 * drm_kms_helper_poll_fini - disable output polling and clean it up 535 * @dev: drm_device 536 */ 537 void drm_kms_helper_poll_fini(struct drm_device *dev) 538 { 539 drm_kms_helper_poll_disable(dev); 540 } 541 EXPORT_SYMBOL(drm_kms_helper_poll_fini); 542 543 /** 544 * drm_helper_hpd_irq_event - hotplug processing 545 * @dev: drm_device 546 * 547 * Drivers can use this helper function to run a detect cycle on all connectors 548 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All 549 * other connectors are ignored, which is useful to avoid reprobing fixed 550 * panels. 551 * 552 * This helper function is useful for drivers which can't or don't track hotplug 553 * interrupts for each connector. 554 * 555 * Drivers which support hotplug interrupts for each connector individually and 556 * which have a more fine-grained detect logic should bypass this code and 557 * directly call drm_kms_helper_hotplug_event() in case the connector state 558 * changed. 559 * 560 * This function must be called from process context with no mode 561 * setting locks held. 562 * 563 * Note that a connector can be both polled and probed from the hotplug handler, 564 * in case the hotplug interrupt is known to be unreliable. 565 */ 566 bool drm_helper_hpd_irq_event(struct drm_device *dev) 567 { 568 struct drm_connector *connector; 569 struct drm_connector_list_iter conn_iter; 570 enum drm_connector_status old_status; 571 bool changed = false; 572 573 if (!dev->mode_config.poll_enabled) 574 return false; 575 576 mutex_lock(&dev->mode_config.mutex); 577 drm_connector_list_iter_get(dev, &conn_iter); 578 drm_for_each_connector_iter(connector, &conn_iter) { 579 /* Only handle HPD capable connectors. */ 580 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) 581 continue; 582 583 old_status = connector->status; 584 585 connector->status = drm_connector_detect(connector, false); 586 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", 587 connector->base.id, 588 connector->name, 589 drm_get_connector_status_name(old_status), 590 drm_get_connector_status_name(connector->status)); 591 if (old_status != connector->status) 592 changed = true; 593 } 594 drm_connector_list_iter_put(&conn_iter); 595 mutex_unlock(&dev->mode_config.mutex); 596 597 if (changed) 598 drm_kms_helper_hotplug_event(dev); 599 600 return changed; 601 } 602 EXPORT_SYMBOL(drm_helper_hpd_irq_event); 603