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