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>
35 #include <drm/drm_bridge.h>
36 #include <drm/drm_client.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_edid.h>
39 #include <drm/drm_fourcc.h>
40 #include <drm/drm_modeset_helper_vtables.h>
41 #include <drm/drm_print.h>
42 #include <drm/drm_probe_helper.h>
43 #include <drm/drm_sysfs.h>
45 #include "drm_crtc_helper_internal.h"
48 * DOC: output probing helper overview
50 * This library provides some helper code for output probing. It provides an
51 * implementation of the core &drm_connector_funcs.fill_modes interface with
52 * drm_helper_probe_single_connector_modes().
54 * It also provides support for polling connectors with a work item and for
55 * generic hotplug interrupt handling where the driver doesn't or cannot keep
56 * track of a per-connector hpd interrupt.
58 * This helper library can be used independently of the modeset helper library.
59 * Drivers can also overwrite different parts e.g. use their own hotplug
60 * handling code to avoid probing unrelated outputs.
62 * The probe helpers share the function table structures with other display
63 * helper libraries. See &struct drm_connector_helper_funcs for the details.
66 static bool drm_kms_helper_poll = true;
67 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
69 static enum drm_mode_status
70 drm_mode_validate_flag(const struct drm_display_mode *mode,
73 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
74 !(flags & DRM_MODE_FLAG_INTERLACE))
75 return MODE_NO_INTERLACE;
77 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
78 !(flags & DRM_MODE_FLAG_DBLSCAN))
79 return MODE_NO_DBLESCAN;
81 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
82 !(flags & DRM_MODE_FLAG_3D_MASK))
83 return MODE_NO_STEREO;
89 drm_mode_validate_pipeline(struct drm_display_mode *mode,
90 struct drm_connector *connector,
91 struct drm_modeset_acquire_ctx *ctx,
92 enum drm_mode_status *status)
94 struct drm_device *dev = connector->dev;
95 struct drm_encoder *encoder;
98 /* Step 1: Validate against connector */
99 ret = drm_connector_mode_valid(connector, mode, ctx, status);
100 if (ret || *status != MODE_OK)
103 /* Step 2: Validate against encoders and crtcs */
104 drm_connector_for_each_possible_encoder(connector, encoder) {
105 struct drm_bridge *bridge;
106 struct drm_crtc *crtc;
108 *status = drm_encoder_mode_valid(encoder, mode);
109 if (*status != MODE_OK) {
110 /* No point in continuing for crtc check as this encoder
111 * will not accept the mode anyway. If all encoders
112 * reject the mode then, at exit, ret will not be
117 bridge = drm_bridge_chain_get_first_bridge(encoder);
118 *status = drm_bridge_chain_mode_valid(bridge,
119 &connector->display_info,
121 if (*status != MODE_OK) {
122 /* There is also no point in continuing for crtc check
127 drm_for_each_crtc(crtc, dev) {
128 if (!drm_encoder_crtc_ok(encoder, crtc))
131 *status = drm_crtc_mode_valid(crtc, mode);
132 if (*status == MODE_OK) {
133 /* If we get to this point there is at least
134 * one combination of encoder+crtc that works
135 * for this mode. Lets return now. */
144 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
146 struct drm_cmdline_mode *cmdline_mode;
147 struct drm_display_mode *mode;
149 cmdline_mode = &connector->cmdline_mode;
150 if (!cmdline_mode->specified)
153 /* Only add a GTF mode if we find no matching probed modes */
154 list_for_each_entry(mode, &connector->probed_modes, head) {
155 if (mode->hdisplay != cmdline_mode->xres ||
156 mode->vdisplay != cmdline_mode->yres)
159 if (cmdline_mode->refresh_specified) {
160 /* The probed mode's vrefresh is set until later */
161 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
165 /* Mark the matching mode as being preferred by the user */
166 mode->type |= DRM_MODE_TYPE_USERDEF;
170 mode = drm_mode_create_from_cmdline_mode(connector->dev,
175 drm_mode_probed_add(connector, mode);
179 enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
180 const struct drm_display_mode *mode)
182 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
184 if (!crtc_funcs || !crtc_funcs->mode_valid)
187 return crtc_funcs->mode_valid(crtc, mode);
190 enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
191 const struct drm_display_mode *mode)
193 const struct drm_encoder_helper_funcs *encoder_funcs =
194 encoder->helper_private;
196 if (!encoder_funcs || !encoder_funcs->mode_valid)
199 return encoder_funcs->mode_valid(encoder, mode);
203 drm_connector_mode_valid(struct drm_connector *connector,
204 struct drm_display_mode *mode,
205 struct drm_modeset_acquire_ctx *ctx,
206 enum drm_mode_status *status)
208 const struct drm_connector_helper_funcs *connector_funcs =
209 connector->helper_private;
212 if (!connector_funcs)
214 else if (connector_funcs->mode_valid_ctx)
215 ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
217 else if (connector_funcs->mode_valid)
218 *status = connector_funcs->mode_valid(connector, mode);
225 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
227 * drm_kms_helper_poll_enable - re-enable output polling.
230 * This function re-enables the output polling work, after it has been
231 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
234 * Drivers can call this helper from their device resume implementation. It is
235 * not an error to call this even when output polling isn't enabled.
237 * Note that calls to enable and disable polling must be strictly ordered, which
238 * is automatically the case when they're only call from suspend/resume
241 void drm_kms_helper_poll_enable(struct drm_device *dev)
244 struct drm_connector *connector;
245 struct drm_connector_list_iter conn_iter;
246 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
248 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
251 drm_connector_list_iter_begin(dev, &conn_iter);
252 drm_for_each_connector_iter(connector, &conn_iter) {
253 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
254 DRM_CONNECTOR_POLL_DISCONNECT))
257 drm_connector_list_iter_end(&conn_iter);
259 if (dev->mode_config.delayed_event) {
263 * Use short (1s) delay to handle the initial delayed event.
264 * This delay should not be needed, but Optimus/nouveau will
265 * fail in a mysterious way if the delayed event is handled as
266 * soon as possible like it is done in
267 * drm_helper_probe_single_connector_modes() in case the poll
268 * was enabled before.
275 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
277 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
279 static enum drm_connector_status
280 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
282 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
283 struct drm_modeset_acquire_ctx ctx;
286 drm_modeset_acquire_init(&ctx, 0);
289 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
291 if (funcs->detect_ctx)
292 ret = funcs->detect_ctx(connector, &ctx, force);
293 else if (connector->funcs->detect)
294 ret = connector->funcs->detect(connector, force);
296 ret = connector_status_connected;
299 if (ret == -EDEADLK) {
300 drm_modeset_backoff(&ctx);
304 if (WARN_ON(ret < 0))
305 ret = connector_status_unknown;
307 if (ret != connector->status)
308 connector->epoch_counter += 1;
310 drm_modeset_drop_locks(&ctx);
311 drm_modeset_acquire_fini(&ctx);
317 * drm_helper_probe_detect - probe connector status
318 * @connector: connector to probe
319 * @ctx: acquire_ctx, or NULL to let this function handle locking.
320 * @force: Whether destructive probe operations should be performed.
322 * This function calls the detect callbacks of the connector.
323 * This function returns &drm_connector_status, or
324 * if @ctx is set, it might also return -EDEADLK.
327 drm_helper_probe_detect(struct drm_connector *connector,
328 struct drm_modeset_acquire_ctx *ctx,
331 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
332 struct drm_device *dev = connector->dev;
336 return drm_helper_probe_detect_ctx(connector, force);
338 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
342 if (funcs->detect_ctx)
343 ret = funcs->detect_ctx(connector, ctx, force);
344 else if (connector->funcs->detect)
345 ret = connector->funcs->detect(connector, force);
347 ret = connector_status_connected;
349 if (ret != connector->status)
350 connector->epoch_counter += 1;
354 EXPORT_SYMBOL(drm_helper_probe_detect);
356 static int drm_helper_probe_get_modes(struct drm_connector *connector)
358 const struct drm_connector_helper_funcs *connector_funcs =
359 connector->helper_private;
362 count = connector_funcs->get_modes(connector);
365 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
366 * override/firmware EDID.
368 if (count == 0 && connector->status == connector_status_connected)
369 count = drm_edid_override_connector_update(connector);
374 static int __drm_helper_update_and_validate(struct drm_connector *connector,
375 uint32_t maxX, uint32_t maxY,
376 struct drm_modeset_acquire_ctx *ctx)
378 struct drm_device *dev = connector->dev;
379 struct drm_display_mode *mode;
383 drm_connector_list_update(connector);
385 if (connector->interlace_allowed)
386 mode_flags |= DRM_MODE_FLAG_INTERLACE;
387 if (connector->doublescan_allowed)
388 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
389 if (connector->stereo_allowed)
390 mode_flags |= DRM_MODE_FLAG_3D_MASK;
392 list_for_each_entry(mode, &connector->modes, head) {
393 if (mode->status != MODE_OK)
396 mode->status = drm_mode_validate_driver(dev, mode);
397 if (mode->status != MODE_OK)
400 mode->status = drm_mode_validate_size(mode, maxX, maxY);
401 if (mode->status != MODE_OK)
404 mode->status = drm_mode_validate_flag(mode, mode_flags);
405 if (mode->status != MODE_OK)
408 ret = drm_mode_validate_pipeline(mode, connector, ctx,
412 "drm_mode_validate_pipeline failed: %d\n",
415 if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK))
416 mode->status = MODE_ERROR;
421 if (mode->status != MODE_OK)
423 mode->status = drm_mode_validate_ycbcr420(mode, connector);
430 * drm_helper_probe_single_connector_modes - get complete set of display modes
431 * @connector: connector to probe
432 * @maxX: max width for modes
433 * @maxY: max height for modes
435 * Based on the helper callbacks implemented by @connector in struct
436 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
437 * be added to the connector's probed_modes list, then culled (based on validity
438 * and the @maxX, @maxY parameters) and put into the normal modes list.
440 * Intended to be used as a generic implementation of the
441 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
442 * for output mode filtering and detection.
444 * The basic procedure is as follows
446 * 1. All modes currently on the connector's modes list are marked as stale
448 * 2. New modes are added to the connector's probed_modes list with
449 * drm_mode_probed_add(). New modes start their life with status as OK.
450 * Modes are added from a single source using the following priority order.
452 * - &drm_connector_helper_funcs.get_modes vfunc
453 * - if the connector status is connector_status_connected, standard
454 * VESA DMT modes up to 1024x768 are automatically added
455 * (drm_add_modes_noedid())
457 * Finally modes specified via the kernel command line (video=...) are
458 * added in addition to what the earlier probes produced
459 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
460 * using the VESA GTF/CVT formulas.
462 * 3. Modes are moved from the probed_modes list to the modes list. Potential
463 * duplicates are merged together (see drm_connector_list_update()).
464 * After this step the probed_modes list will be empty again.
466 * 4. Any non-stale mode on the modes list then undergoes validation
468 * - drm_mode_validate_basic() performs basic sanity checks
469 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
471 * - drm_mode_validate_flag() checks the modes against basic connector
472 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
473 * - the optional &drm_connector_helper_funcs.mode_valid or
474 * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
475 * and/or sink specific checks
476 * - the optional &drm_crtc_helper_funcs.mode_valid,
477 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
478 * helpers can perform driver and/or source specific checks which are also
479 * enforced by the modeset/atomic helpers
481 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
482 * accompanied by a debug message indicating the reason for the mode's
483 * rejection (see drm_mode_prune_invalid()).
486 * The number of modes found on @connector.
488 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
489 uint32_t maxX, uint32_t maxY)
491 struct drm_device *dev = connector->dev;
492 struct drm_display_mode *mode;
494 enum drm_connector_status old_status;
495 struct drm_modeset_acquire_ctx ctx;
497 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
499 drm_modeset_acquire_init(&ctx, 0);
501 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
505 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
506 if (ret == -EDEADLK) {
507 drm_modeset_backoff(&ctx);
512 /* set all old modes to the stale state */
513 list_for_each_entry(mode, &connector->modes, head)
514 mode->status = MODE_STALE;
516 old_status = connector->status;
518 if (connector->force) {
519 if (connector->force == DRM_FORCE_ON ||
520 connector->force == DRM_FORCE_ON_DIGITAL)
521 connector->status = connector_status_connected;
523 connector->status = connector_status_disconnected;
524 if (connector->funcs->force)
525 connector->funcs->force(connector);
527 ret = drm_helper_probe_detect(connector, &ctx, true);
529 if (ret == -EDEADLK) {
530 drm_modeset_backoff(&ctx);
532 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
533 ret = connector_status_unknown;
535 connector->status = ret;
539 * Normally either the driver's hpd code or the poll loop should
540 * pick up any changes and fire the hotplug event. But if
541 * userspace sneaks in a probe, we might miss a change. Hence
542 * check here, and if anything changed start the hotplug code.
544 if (old_status != connector->status) {
545 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
548 drm_get_connector_status_name(old_status),
549 drm_get_connector_status_name(connector->status));
552 * The hotplug event code might call into the fb
553 * helpers, and so expects that we do not hold any
554 * locks. Fire up the poll struct instead, it will
555 * disable itself again.
557 dev->mode_config.delayed_event = true;
558 if (dev->mode_config.poll_enabled)
559 schedule_delayed_work(&dev->mode_config.output_poll_work,
563 /* Re-enable polling in case the global poll config changed. */
564 if (drm_kms_helper_poll != dev->mode_config.poll_running)
565 drm_kms_helper_poll_enable(dev);
567 dev->mode_config.poll_running = drm_kms_helper_poll;
569 if (connector->status == connector_status_disconnected) {
570 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
571 connector->base.id, connector->name);
572 drm_connector_update_edid_property(connector, NULL);
573 drm_mode_prune_invalid(dev, &connector->modes, false);
577 count = drm_helper_probe_get_modes(connector);
579 if (count == 0 && (connector->status == connector_status_connected ||
580 connector->status == connector_status_unknown)) {
581 count = drm_add_modes_noedid(connector, 1024, 768);
584 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
585 * Link CTS specifies that 640x480 (the official "failsafe"
586 * mode) needs to be the default if there's no EDID.
588 if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
589 drm_set_preferred_mode(connector, 640, 480);
591 count += drm_helper_probe_add_cmdline_mode(connector);
593 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
594 if (ret == -EDEADLK) {
595 drm_modeset_backoff(&ctx);
600 drm_mode_prune_invalid(dev, &connector->modes, true);
603 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
604 * all detachable sinks shall support 640x480 @60Hz as a fail safe
605 * mode. If all modes were pruned, perhaps because they need more
606 * lanes or a higher pixel clock than available, at least try to add
609 if (list_empty(&connector->modes) &&
610 connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
611 count = drm_add_modes_noedid(connector, 640, 480);
612 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
613 if (ret == -EDEADLK) {
614 drm_modeset_backoff(&ctx);
617 drm_mode_prune_invalid(dev, &connector->modes, true);
621 drm_modeset_drop_locks(&ctx);
622 drm_modeset_acquire_fini(&ctx);
624 if (list_empty(&connector->modes))
627 drm_mode_sort(&connector->modes);
629 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
631 list_for_each_entry(mode, &connector->modes, head) {
632 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
633 drm_mode_debug_printmodeline(mode);
638 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
641 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
642 * @dev: drm_device whose connector state changed
644 * This function fires off the uevent for userspace and also calls the
645 * output_poll_changed function, which is most commonly used to inform the fbdev
646 * emulation code and allow it to update the fbcon output configuration.
648 * Drivers should call this from their hotplug handling code when a change is
649 * detected. Note that this function does not do any output detection of its
650 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
653 * This function must be called from process context with no mode
654 * setting locks held.
656 * If only a single connector has changed, consider calling
657 * drm_kms_helper_connector_hotplug_event() instead.
659 void drm_kms_helper_hotplug_event(struct drm_device *dev)
661 /* send a uevent + call fbdev */
662 drm_sysfs_hotplug_event(dev);
663 if (dev->mode_config.funcs->output_poll_changed)
664 dev->mode_config.funcs->output_poll_changed(dev);
666 drm_client_dev_hotplug(dev);
668 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
671 * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
672 * @connector: drm_connector which has changed
674 * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
675 * fine-grained uevent for a single connector.
677 void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
679 struct drm_device *dev = connector->dev;
681 /* send a uevent + call fbdev */
682 drm_sysfs_connector_hotplug_event(connector);
683 if (dev->mode_config.funcs->output_poll_changed)
684 dev->mode_config.funcs->output_poll_changed(dev);
686 drm_client_dev_hotplug(dev);
688 EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
690 static void output_poll_execute(struct work_struct *work)
692 struct delayed_work *delayed_work = to_delayed_work(work);
693 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
694 struct drm_connector *connector;
695 struct drm_connector_list_iter conn_iter;
696 enum drm_connector_status old_status;
697 bool repoll = false, changed;
698 u64 old_epoch_counter;
700 if (!dev->mode_config.poll_enabled)
703 /* Pick up any changes detected by the probe functions. */
704 changed = dev->mode_config.delayed_event;
705 dev->mode_config.delayed_event = false;
707 if (!drm_kms_helper_poll)
710 if (!mutex_trylock(&dev->mode_config.mutex)) {
715 drm_connector_list_iter_begin(dev, &conn_iter);
716 drm_for_each_connector_iter(connector, &conn_iter) {
717 /* Ignore forced connectors. */
718 if (connector->force)
721 /* Ignore HPD capable connectors and connectors where we don't
722 * want any hotplug detection at all for polling. */
723 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
726 old_status = connector->status;
727 /* if we are connected and don't want to poll for disconnect
729 if (old_status == connector_status_connected &&
730 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
735 old_epoch_counter = connector->epoch_counter;
736 connector->status = drm_helper_probe_detect(connector, NULL, false);
737 if (old_epoch_counter != connector->epoch_counter) {
738 const char *old, *new;
741 * The poll work sets force=false when calling detect so
742 * that drivers can avoid to do disruptive tests (e.g.
743 * when load detect cycles could cause flickering on
744 * other, running displays). This bears the risk that we
745 * flip-flop between unknown here in the poll work and
746 * the real state when userspace forces a full detect
747 * call after receiving a hotplug event due to this
750 * Hence clamp an unknown detect status to the old
753 if (connector->status == connector_status_unknown) {
754 connector->status = old_status;
758 old = drm_get_connector_status_name(old_status);
759 new = drm_get_connector_status_name(connector->status);
761 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
762 "status updated from %s to %s\n",
766 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
767 connector->base.id, connector->name,
768 old_epoch_counter, connector->epoch_counter);
773 drm_connector_list_iter_end(&conn_iter);
775 mutex_unlock(&dev->mode_config.mutex);
779 drm_kms_helper_hotplug_event(dev);
782 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
786 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
788 * Determine if %current task is an output poll worker. This can be used
789 * to select distinct code paths for output polling versus other contexts.
791 * One use case is to avoid a deadlock between the output poll worker and
792 * the autosuspend worker wherein the latter waits for polling to finish
793 * upon calling drm_kms_helper_poll_disable(), while the former waits for
794 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
795 * connector ->detect hook.
797 bool drm_kms_helper_is_poll_worker(void)
799 struct work_struct *work = current_work();
801 return work && work->func == output_poll_execute;
803 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
806 * drm_kms_helper_poll_disable - disable output polling
809 * This function disables the output polling work.
811 * Drivers can call this helper from their device suspend implementation. It is
812 * not an error to call this even when output polling isn't enabled or already
813 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
815 * Note that calls to enable and disable polling must be strictly ordered, which
816 * is automatically the case when they're only call from suspend/resume
819 void drm_kms_helper_poll_disable(struct drm_device *dev)
821 if (!dev->mode_config.poll_enabled)
823 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
825 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
828 * drm_kms_helper_poll_init - initialize and enable output polling
831 * This function initializes and then also enables output polling support for
832 * @dev. Drivers which do not have reliable hotplug support in hardware can use
833 * this helper infrastructure to regularly poll such connectors for changes in
834 * their connection state.
836 * Drivers can control which connectors are polled by setting the
837 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
838 * connectors where probing live outputs can result in visual distortion drivers
839 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
840 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
841 * completely ignored by the polling logic.
843 * Note that a connector can be both polled and probed from the hotplug handler,
844 * in case the hotplug interrupt is known to be unreliable.
846 void drm_kms_helper_poll_init(struct drm_device *dev)
848 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
849 dev->mode_config.poll_enabled = true;
851 drm_kms_helper_poll_enable(dev);
853 EXPORT_SYMBOL(drm_kms_helper_poll_init);
856 * drm_kms_helper_poll_fini - disable output polling and clean it up
859 void drm_kms_helper_poll_fini(struct drm_device *dev)
861 if (!dev->mode_config.poll_enabled)
864 dev->mode_config.poll_enabled = false;
865 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
867 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
869 static bool check_connector_changed(struct drm_connector *connector)
871 struct drm_device *dev = connector->dev;
872 enum drm_connector_status old_status;
873 u64 old_epoch_counter;
875 /* Only handle HPD capable connectors. */
876 drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
878 drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
880 old_status = connector->status;
881 old_epoch_counter = connector->epoch_counter;
882 connector->status = drm_helper_probe_detect(connector, NULL, false);
884 if (old_epoch_counter == connector->epoch_counter) {
885 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
888 connector->epoch_counter);
893 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
896 drm_get_connector_status_name(old_status),
897 drm_get_connector_status_name(connector->status));
899 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
903 connector->epoch_counter);
909 * drm_connector_helper_hpd_irq_event - hotplug processing
910 * @connector: drm_connector
912 * Drivers can use this helper function to run a detect cycle on a connector
913 * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
915 * This helper function is useful for drivers which can track hotplug
916 * interrupts for a single connector. Drivers that want to send a
917 * hotplug event for all connectors or can't track hotplug interrupts
918 * per connector need to use drm_helper_hpd_irq_event().
920 * This function must be called from process context with no mode
921 * setting locks held.
923 * Note that a connector can be both polled and probed from the hotplug
924 * handler, in case the hotplug interrupt is known to be unreliable.
927 * A boolean indicating whether the connector status changed or not
929 bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
931 struct drm_device *dev = connector->dev;
934 mutex_lock(&dev->mode_config.mutex);
935 changed = check_connector_changed(connector);
936 mutex_unlock(&dev->mode_config.mutex);
939 drm_kms_helper_connector_hotplug_event(connector);
940 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
947 EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
950 * drm_helper_hpd_irq_event - hotplug processing
953 * Drivers can use this helper function to run a detect cycle on all connectors
954 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
955 * other connectors are ignored, which is useful to avoid reprobing fixed
958 * This helper function is useful for drivers which can't or don't track hotplug
959 * interrupts for each connector.
961 * Drivers which support hotplug interrupts for each connector individually and
962 * which have a more fine-grained detect logic can use
963 * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
964 * code and directly call drm_kms_helper_hotplug_event() in case the connector
967 * This function must be called from process context with no mode
968 * setting locks held.
970 * Note that a connector can be both polled and probed from the hotplug handler,
971 * in case the hotplug interrupt is known to be unreliable.
974 * A boolean indicating whether the connector status changed or not
976 bool drm_helper_hpd_irq_event(struct drm_device *dev)
978 struct drm_connector *connector, *first_changed_connector = NULL;
979 struct drm_connector_list_iter conn_iter;
982 if (!dev->mode_config.poll_enabled)
985 mutex_lock(&dev->mode_config.mutex);
986 drm_connector_list_iter_begin(dev, &conn_iter);
987 drm_for_each_connector_iter(connector, &conn_iter) {
988 /* Only handle HPD capable connectors. */
989 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
992 if (check_connector_changed(connector)) {
993 if (!first_changed_connector) {
994 drm_connector_get(connector);
995 first_changed_connector = connector;
1001 drm_connector_list_iter_end(&conn_iter);
1002 mutex_unlock(&dev->mode_config.mutex);
1005 drm_kms_helper_connector_hotplug_event(first_changed_connector);
1006 else if (changed > 0)
1007 drm_kms_helper_hotplug_event(dev);
1009 if (first_changed_connector)
1010 drm_connector_put(first_changed_connector);
1014 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
1017 * drm_crtc_helper_mode_valid_fixed - Validates a display mode
1019 * @mode: the mode to validate
1020 * @fixed_mode: the display hardware's mode
1023 * MODE_OK on success, or another mode-status code otherwise.
1025 enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc,
1026 const struct drm_display_mode *mode,
1027 const struct drm_display_mode *fixed_mode)
1029 if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay)
1030 return MODE_ONE_SIZE;
1031 else if (mode->hdisplay != fixed_mode->hdisplay)
1032 return MODE_ONE_WIDTH;
1033 else if (mode->vdisplay != fixed_mode->vdisplay)
1034 return MODE_ONE_HEIGHT;
1038 EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed);
1041 * drm_connector_helper_get_modes_from_ddc - Updates the connector's EDID
1042 * property from the connector's
1044 * @connector: The connector
1047 * The number of detected display modes.
1049 * Uses a connector's DDC channel to retrieve EDID data and update the
1050 * connector's EDID property and display modes. Drivers can use this
1051 * function to implement struct &drm_connector_helper_funcs.get_modes
1052 * for connectors with a DDC channel.
1054 int drm_connector_helper_get_modes_from_ddc(struct drm_connector *connector)
1059 if (!connector->ddc)
1062 edid = drm_get_edid(connector, connector->ddc);
1064 // clears property if EDID is NULL
1065 drm_connector_update_edid_property(connector, edid);
1068 count = drm_add_edid_modes(connector, edid);
1074 EXPORT_SYMBOL(drm_connector_helper_get_modes_from_ddc);
1077 * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
1078 * @connector: the connector
1079 * @fixed_mode: the display hardware's mode
1081 * This function duplicates a display modes for a connector. Drivers for hardware
1082 * that only supports a single fixed mode can use this function in their connector's
1086 * The number of created modes.
1088 int drm_connector_helper_get_modes_fixed(struct drm_connector *connector,
1089 const struct drm_display_mode *fixed_mode)
1091 struct drm_device *dev = connector->dev;
1092 struct drm_display_mode *mode;
1094 mode = drm_mode_duplicate(dev, fixed_mode);
1096 drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n",
1097 DRM_MODE_ARG(fixed_mode));
1101 if (mode->name[0] == '\0')
1102 drm_mode_set_name(mode);
1104 mode->type |= DRM_MODE_TYPE_PREFERRED;
1105 drm_mode_probed_add(connector, mode);
1108 connector->display_info.width_mm = mode->width_mm;
1109 if (mode->height_mm)
1110 connector->display_info.height_mm = mode->height_mm;
1114 EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed);
1117 * drm_connector_helper_get_modes - Read EDID and update connector.
1118 * @connector: The connector
1120 * Read the EDID using drm_edid_read() (which requires that connector->ddc is
1121 * set), and update the connector using the EDID.
1123 * This can be used as the "default" connector helper .get_modes() hook if the
1124 * driver does not need any special processing. This is sets the example what
1125 * custom .get_modes() hooks should do regarding EDID read and connector update.
1127 * Returns: Number of modes.
1129 int drm_connector_helper_get_modes(struct drm_connector *connector)
1131 const struct drm_edid *drm_edid;
1134 drm_edid = drm_edid_read(connector);
1137 * Unconditionally update the connector. If the EDID was read
1138 * successfully, fill in the connector information derived from the
1139 * EDID. Otherwise, if the EDID is NULL, clear the connector
1142 count = drm_edid_connector_update(connector, drm_edid);
1144 drm_edid_free(drm_edid);
1148 EXPORT_SYMBOL(drm_connector_helper_get_modes);