2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
5 * DRM core CRTC related functions
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.
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
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
32 #include <linux/export.h>
33 #include <linux/moduleparam.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>
43 * DOC: output probing helper overview
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().
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.
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.
57 * The probe helpers share the function table structures with other display
58 * helper libraries. See &struct drm_connector_helper_funcs for the details.
61 static bool drm_kms_helper_poll = true;
62 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
64 static enum drm_mode_status
65 drm_mode_validate_flag(const struct drm_display_mode *mode,
68 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
69 !(flags & DRM_MODE_FLAG_INTERLACE))
70 return MODE_NO_INTERLACE;
72 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
73 !(flags & DRM_MODE_FLAG_DBLSCAN))
74 return MODE_NO_DBLESCAN;
76 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
77 !(flags & DRM_MODE_FLAG_3D_MASK))
78 return MODE_NO_STEREO;
83 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
85 struct drm_cmdline_mode *cmdline_mode;
86 struct drm_display_mode *mode;
88 cmdline_mode = &connector->cmdline_mode;
89 if (!cmdline_mode->specified)
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)
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)
107 mode = drm_mode_create_from_cmdline_mode(connector->dev,
112 drm_mode_probed_add(connector, mode);
116 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
118 * drm_kms_helper_poll_enable - re-enable output polling.
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
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
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
133 void drm_kms_helper_poll_enable(struct drm_device *dev)
136 struct drm_connector *connector;
137 struct drm_connector_list_iter conn_iter;
138 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
140 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
143 drm_connector_list_iter_begin(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))
149 drm_connector_list_iter_end(&conn_iter);
151 if (dev->mode_config.delayed_event) {
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.
167 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
169 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
171 static enum drm_connector_status
172 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
174 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
175 struct drm_modeset_acquire_ctx ctx;
178 drm_modeset_acquire_init(&ctx, 0);
181 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
183 if (funcs->detect_ctx)
184 ret = funcs->detect_ctx(connector, &ctx, force);
185 else if (connector->funcs->detect)
186 ret = connector->funcs->detect(connector, force);
188 ret = connector_status_connected;
191 if (ret == -EDEADLK) {
192 drm_modeset_backoff(&ctx);
196 if (WARN_ON(ret < 0))
197 ret = connector_status_unknown;
199 drm_modeset_drop_locks(&ctx);
200 drm_modeset_acquire_fini(&ctx);
206 * drm_helper_probe_detect - probe connector status
207 * @connector: connector to probe
208 * @ctx: acquire_ctx, or NULL to let this function handle locking.
209 * @force: Whether destructive probe operations should be performed.
211 * This function calls the detect callbacks of the connector.
212 * This function returns &drm_connector_status, or
213 * if @ctx is set, it might also return -EDEADLK.
216 drm_helper_probe_detect(struct drm_connector *connector,
217 struct drm_modeset_acquire_ctx *ctx,
220 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
221 struct drm_device *dev = connector->dev;
225 return drm_helper_probe_detect_ctx(connector, force);
227 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
231 if (funcs->detect_ctx)
232 return funcs->detect_ctx(connector, ctx, force);
233 else if (connector->funcs->detect)
234 return connector->funcs->detect(connector, force);
236 return connector_status_connected;
238 EXPORT_SYMBOL(drm_helper_probe_detect);
241 * drm_helper_probe_single_connector_modes - get complete set of display modes
242 * @connector: connector to probe
243 * @maxX: max width for modes
244 * @maxY: max height for modes
246 * Based on the helper callbacks implemented by @connector in struct
247 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
248 * be added to the connector's probed_modes list, then culled (based on validity
249 * and the @maxX, @maxY parameters) and put into the normal modes list.
251 * Intended to be used as a generic implementation of the
252 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
253 * for output mode filtering and detection.
255 * The basic procedure is as follows
257 * 1. All modes currently on the connector's modes list are marked as stale
259 * 2. New modes are added to the connector's probed_modes list with
260 * drm_mode_probed_add(). New modes start their life with status as OK.
261 * Modes are added from a single source using the following priority order.
263 * - debugfs 'override_edid' (used for testing only)
264 * - firmware EDID (drm_load_edid_firmware())
265 * - &drm_connector_helper_funcs.get_modes vfunc
266 * - if the connector status is connector_status_connected, standard
267 * VESA DMT modes up to 1024x768 are automatically added
268 * (drm_add_modes_noedid())
270 * Finally modes specified via the kernel command line (video=...) are
271 * added in addition to what the earlier probes produced
272 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
273 * using the VESA GTF/CVT formulas.
275 * 3. Modes are moved from the probed_modes list to the modes list. Potential
276 * duplicates are merged together (see drm_mode_connector_list_update()).
277 * After this step the probed_modes list will be empty again.
279 * 4. Any non-stale mode on the modes list then undergoes validation
281 * - drm_mode_validate_basic() performs basic sanity checks
282 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
284 * - drm_mode_validate_flag() checks the modes against basic connector
285 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
286 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform
287 * driver and/or hardware specific checks
289 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
290 * accompanied by a debug message indicating the reason for the mode's
291 * rejection (see drm_mode_prune_invalid()).
294 * The number of modes found on @connector.
296 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
297 uint32_t maxX, uint32_t maxY)
299 struct drm_device *dev = connector->dev;
300 struct drm_display_mode *mode;
301 const struct drm_connector_helper_funcs *connector_funcs =
302 connector->helper_private;
305 bool verbose_prune = true;
306 enum drm_connector_status old_status;
307 struct drm_modeset_acquire_ctx ctx;
309 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
311 drm_modeset_acquire_init(&ctx, 0);
313 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
317 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
318 if (ret == -EDEADLK) {
319 drm_modeset_backoff(&ctx);
324 /* set all old modes to the stale state */
325 list_for_each_entry(mode, &connector->modes, head)
326 mode->status = MODE_STALE;
328 old_status = connector->status;
330 if (connector->force) {
331 if (connector->force == DRM_FORCE_ON ||
332 connector->force == DRM_FORCE_ON_DIGITAL)
333 connector->status = connector_status_connected;
335 connector->status = connector_status_disconnected;
336 if (connector->funcs->force)
337 connector->funcs->force(connector);
339 ret = drm_helper_probe_detect(connector, &ctx, true);
341 if (ret == -EDEADLK) {
342 drm_modeset_backoff(&ctx);
344 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
345 ret = connector_status_unknown;
347 connector->status = ret;
351 * Normally either the driver's hpd code or the poll loop should
352 * pick up any changes and fire the hotplug event. But if
353 * userspace sneaks in a probe, we might miss a change. Hence
354 * check here, and if anything changed start the hotplug code.
356 if (old_status != connector->status) {
357 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
360 drm_get_connector_status_name(old_status),
361 drm_get_connector_status_name(connector->status));
364 * The hotplug event code might call into the fb
365 * helpers, and so expects that we do not hold any
366 * locks. Fire up the poll struct instead, it will
367 * disable itself again.
369 dev->mode_config.delayed_event = true;
370 if (dev->mode_config.poll_enabled)
371 schedule_delayed_work(&dev->mode_config.output_poll_work,
375 /* Re-enable polling in case the global poll config changed. */
376 if (drm_kms_helper_poll != dev->mode_config.poll_running)
377 drm_kms_helper_poll_enable(dev);
379 dev->mode_config.poll_running = drm_kms_helper_poll;
381 if (connector->status == connector_status_disconnected) {
382 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
383 connector->base.id, connector->name);
384 drm_mode_connector_update_edid_property(connector, NULL);
385 verbose_prune = false;
389 if (connector->override_edid) {
390 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
392 count = drm_add_edid_modes(connector, edid);
393 drm_edid_to_eld(connector, edid);
395 struct edid *edid = drm_load_edid_firmware(connector);
396 if (!IS_ERR_OR_NULL(edid)) {
397 drm_mode_connector_update_edid_property(connector, edid);
398 count = drm_add_edid_modes(connector, edid);
399 drm_edid_to_eld(connector, edid);
403 count = (*connector_funcs->get_modes)(connector);
406 if (count == 0 && connector->status == connector_status_connected)
407 count = drm_add_modes_noedid(connector, 1024, 768);
408 count += drm_helper_probe_add_cmdline_mode(connector);
412 drm_mode_connector_list_update(connector);
414 if (connector->interlace_allowed)
415 mode_flags |= DRM_MODE_FLAG_INTERLACE;
416 if (connector->doublescan_allowed)
417 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
418 if (connector->stereo_allowed)
419 mode_flags |= DRM_MODE_FLAG_3D_MASK;
421 list_for_each_entry(mode, &connector->modes, head) {
422 if (mode->status == MODE_OK)
423 mode->status = drm_mode_validate_basic(mode);
425 if (mode->status == MODE_OK)
426 mode->status = drm_mode_validate_size(mode, maxX, maxY);
428 if (mode->status == MODE_OK)
429 mode->status = drm_mode_validate_flag(mode, mode_flags);
431 if (mode->status == MODE_OK && connector_funcs->mode_valid)
432 mode->status = connector_funcs->mode_valid(connector,
437 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
439 drm_modeset_drop_locks(&ctx);
440 drm_modeset_acquire_fini(&ctx);
442 if (list_empty(&connector->modes))
445 list_for_each_entry(mode, &connector->modes, head)
446 mode->vrefresh = drm_mode_vrefresh(mode);
448 drm_mode_sort(&connector->modes);
450 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
452 list_for_each_entry(mode, &connector->modes, head) {
453 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
454 drm_mode_debug_printmodeline(mode);
459 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
462 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
463 * @dev: drm_device whose connector state changed
465 * This function fires off the uevent for userspace and also calls the
466 * output_poll_changed function, which is most commonly used to inform the fbdev
467 * emulation code and allow it to update the fbcon output configuration.
469 * Drivers should call this from their hotplug handling code when a change is
470 * detected. Note that this function does not do any output detection of its
471 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
474 * This function must be called from process context with no mode
475 * setting locks held.
477 void drm_kms_helper_hotplug_event(struct drm_device *dev)
479 /* send a uevent + call fbdev */
480 drm_sysfs_hotplug_event(dev);
481 if (dev->mode_config.funcs->output_poll_changed)
482 dev->mode_config.funcs->output_poll_changed(dev);
484 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
486 static void output_poll_execute(struct work_struct *work)
488 struct delayed_work *delayed_work = to_delayed_work(work);
489 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
490 struct drm_connector *connector;
491 struct drm_connector_list_iter conn_iter;
492 enum drm_connector_status old_status;
493 bool repoll = false, changed;
495 /* Pick up any changes detected by the probe functions. */
496 changed = dev->mode_config.delayed_event;
497 dev->mode_config.delayed_event = false;
499 if (!drm_kms_helper_poll)
502 if (!mutex_trylock(&dev->mode_config.mutex)) {
507 drm_connector_list_iter_begin(dev, &conn_iter);
508 drm_for_each_connector_iter(connector, &conn_iter) {
509 /* Ignore forced connectors. */
510 if (connector->force)
513 /* Ignore HPD capable connectors and connectors where we don't
514 * want any hotplug detection at all for polling. */
515 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
518 old_status = connector->status;
519 /* if we are connected and don't want to poll for disconnect
521 if (old_status == connector_status_connected &&
522 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
527 connector->status = drm_helper_probe_detect(connector, NULL, false);
528 if (old_status != connector->status) {
529 const char *old, *new;
532 * The poll work sets force=false when calling detect so
533 * that drivers can avoid to do disruptive tests (e.g.
534 * when load detect cycles could cause flickering on
535 * other, running displays). This bears the risk that we
536 * flip-flop between unknown here in the poll work and
537 * the real state when userspace forces a full detect
538 * call after receiving a hotplug event due to this
541 * Hence clamp an unknown detect status to the old
544 if (connector->status == connector_status_unknown) {
545 connector->status = old_status;
549 old = drm_get_connector_status_name(old_status);
550 new = drm_get_connector_status_name(connector->status);
552 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
553 "status updated from %s to %s\n",
561 drm_connector_list_iter_end(&conn_iter);
563 mutex_unlock(&dev->mode_config.mutex);
567 drm_kms_helper_hotplug_event(dev);
570 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
574 * drm_kms_helper_poll_disable - disable output polling
577 * This function disables the output polling work.
579 * Drivers can call this helper from their device suspend implementation. It is
580 * not an error to call this even when output polling isn't enabled or already
581 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
583 * Note that calls to enable and disable polling must be strictly ordered, which
584 * is automatically the case when they're only call from suspend/resume
587 void drm_kms_helper_poll_disable(struct drm_device *dev)
589 if (!dev->mode_config.poll_enabled)
591 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
593 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
596 * drm_kms_helper_poll_init - initialize and enable output polling
599 * This function intializes and then also enables output polling support for
600 * @dev. Drivers which do not have reliable hotplug support in hardware can use
601 * this helper infrastructure to regularly poll such connectors for changes in
602 * their connection state.
604 * Drivers can control which connectors are polled by setting the
605 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
606 * connectors where probing live outputs can result in visual distortion drivers
607 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
608 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
609 * completely ignored by the polling logic.
611 * Note that a connector can be both polled and probed from the hotplug handler,
612 * in case the hotplug interrupt is known to be unreliable.
614 void drm_kms_helper_poll_init(struct drm_device *dev)
616 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
617 dev->mode_config.poll_enabled = true;
619 drm_kms_helper_poll_enable(dev);
621 EXPORT_SYMBOL(drm_kms_helper_poll_init);
624 * drm_kms_helper_poll_fini - disable output polling and clean it up
627 void drm_kms_helper_poll_fini(struct drm_device *dev)
629 drm_kms_helper_poll_disable(dev);
631 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
634 * drm_helper_hpd_irq_event - hotplug processing
637 * Drivers can use this helper function to run a detect cycle on all connectors
638 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
639 * other connectors are ignored, which is useful to avoid reprobing fixed
642 * This helper function is useful for drivers which can't or don't track hotplug
643 * interrupts for each connector.
645 * Drivers which support hotplug interrupts for each connector individually and
646 * which have a more fine-grained detect logic should bypass this code and
647 * directly call drm_kms_helper_hotplug_event() in case the connector state
650 * This function must be called from process context with no mode
651 * setting locks held.
653 * Note that a connector can be both polled and probed from the hotplug handler,
654 * in case the hotplug interrupt is known to be unreliable.
656 bool drm_helper_hpd_irq_event(struct drm_device *dev)
658 struct drm_connector *connector;
659 struct drm_connector_list_iter conn_iter;
660 enum drm_connector_status old_status;
661 bool changed = false;
663 if (!dev->mode_config.poll_enabled)
666 mutex_lock(&dev->mode_config.mutex);
667 drm_connector_list_iter_begin(dev, &conn_iter);
668 drm_for_each_connector_iter(connector, &conn_iter) {
669 /* Only handle HPD capable connectors. */
670 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
673 old_status = connector->status;
675 connector->status = drm_helper_probe_detect(connector, NULL, false);
676 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
679 drm_get_connector_status_name(old_status),
680 drm_get_connector_status_name(connector->status));
681 if (old_status != connector->status)
684 drm_connector_list_iter_end(&conn_iter);
685 mutex_unlock(&dev->mode_config.mutex);
688 drm_kms_helper_hotplug_event(dev);
692 EXPORT_SYMBOL(drm_helper_hpd_irq_event);