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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#include <drm/drm_modeset_helper_vtables.h>
42
43#include "drm_crtc_helper_internal.h"
44
45/**
46 * DOC: output probing helper overview
47 *
48 * This library provides some helper code for output probing. It provides an
49 * implementation of the core &drm_connector_funcs.fill_modes interface with
50 * drm_helper_probe_single_connector_modes().
51 *
52 * It also provides support for polling connectors with a work item and for
53 * generic hotplug interrupt handling where the driver doesn't or cannot keep
54 * track of a per-connector hpd interrupt.
55 *
56 * This helper library can be used independently of the modeset helper library.
57 * Drivers can also overwrite different parts e.g. use their own hotplug
58 * handling code to avoid probing unrelated outputs.
59 *
60 * The probe helpers share the function table structures with other display
61 * helper libraries. See &struct drm_connector_helper_funcs for the details.
62 */
63
64static bool drm_kms_helper_poll = true;
65module_param_named(poll, drm_kms_helper_poll, bool, 0600);
66
67static enum drm_mode_status
68drm_mode_validate_flag(const struct drm_display_mode *mode,
69 int flags)
70{
71 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
72 !(flags & DRM_MODE_FLAG_INTERLACE))
73 return MODE_NO_INTERLACE;
74
75 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
76 !(flags & DRM_MODE_FLAG_DBLSCAN))
77 return MODE_NO_DBLESCAN;
78
79 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
80 !(flags & DRM_MODE_FLAG_3D_MASK))
81 return MODE_NO_STEREO;
82
83 return MODE_OK;
84}
85
86static enum drm_mode_status
87drm_mode_validate_pipeline(struct drm_display_mode *mode,
88 struct drm_connector *connector)
89{
90 struct drm_device *dev = connector->dev;
91 uint32_t *ids = connector->encoder_ids;
92 enum drm_mode_status ret = MODE_OK;
93 unsigned int i;
94
95 /* Step 1: Validate against connector */
96 ret = drm_connector_mode_valid(connector, mode);
97 if (ret != MODE_OK)
98 return ret;
99
100 /* Step 2: Validate against encoders and crtcs */
101 for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
102 struct drm_encoder *encoder = drm_encoder_find(dev, NULL, ids[i]);
103 struct drm_crtc *crtc;
104
105 if (!encoder)
106 continue;
107
108 ret = drm_encoder_mode_valid(encoder, mode);
109 if (ret != 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
113 * MODE_OK. */
114 continue;
115 }
116
117 ret = drm_bridge_mode_valid(encoder->bridge, mode);
118 if (ret != MODE_OK) {
119 /* There is also no point in continuing for crtc check
120 * here. */
121 continue;
122 }
123
124 drm_for_each_crtc(crtc, dev) {
125 if (!drm_encoder_crtc_ok(encoder, crtc))
126 continue;
127
128 ret = drm_crtc_mode_valid(crtc, mode);
129 if (ret == MODE_OK) {
130 /* If we get to this point there is at least
131 * one combination of encoder+crtc that works
132 * for this mode. Lets return now. */
133 return ret;
134 }
135 }
136 }
137
138 return ret;
139}
140
141static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
142{
143 struct drm_cmdline_mode *cmdline_mode;
144 struct drm_display_mode *mode;
145
146 cmdline_mode = &connector->cmdline_mode;
147 if (!cmdline_mode->specified)
148 return 0;
149
150 /* Only add a GTF mode if we find no matching probed modes */
151 list_for_each_entry(mode, &connector->probed_modes, head) {
152 if (mode->hdisplay != cmdline_mode->xres ||
153 mode->vdisplay != cmdline_mode->yres)
154 continue;
155
156 if (cmdline_mode->refresh_specified) {
157 /* The probed mode's vrefresh is set until later */
158 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
159 continue;
160 }
161
162 return 0;
163 }
164
165 mode = drm_mode_create_from_cmdline_mode(connector->dev,
166 cmdline_mode);
167 if (mode == NULL)
168 return 0;
169
170 drm_mode_probed_add(connector, mode);
171 return 1;
172}
173
174enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
175 const struct drm_display_mode *mode)
176{
177 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
178
179 if (!crtc_funcs || !crtc_funcs->mode_valid)
180 return MODE_OK;
181
182 return crtc_funcs->mode_valid(crtc, mode);
183}
184
185enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
186 const struct drm_display_mode *mode)
187{
188 const struct drm_encoder_helper_funcs *encoder_funcs =
189 encoder->helper_private;
190
191 if (!encoder_funcs || !encoder_funcs->mode_valid)
192 return MODE_OK;
193
194 return encoder_funcs->mode_valid(encoder, mode);
195}
196
197enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector,
198 struct drm_display_mode *mode)
199{
200 const struct drm_connector_helper_funcs *connector_funcs =
201 connector->helper_private;
202
203 if (!connector_funcs || !connector_funcs->mode_valid)
204 return MODE_OK;
205
206 return connector_funcs->mode_valid(connector, mode);
207}
208
209#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
210/**
211 * drm_kms_helper_poll_enable - re-enable output polling.
212 * @dev: drm_device
213 *
214 * This function re-enables the output polling work, after it has been
215 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
216 * suspend/resume.
217 *
218 * Drivers can call this helper from their device resume implementation. It is
219 * not an error to call this even when output polling isn't enabled.
220 *
221 * Note that calls to enable and disable polling must be strictly ordered, which
222 * is automatically the case when they're only call from suspend/resume
223 * callbacks.
224 */
225void drm_kms_helper_poll_enable(struct drm_device *dev)
226{
227 bool poll = false;
228 struct drm_connector *connector;
229 struct drm_connector_list_iter conn_iter;
230 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
231
232 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
233 return;
234
235 drm_connector_list_iter_begin(dev, &conn_iter);
236 drm_for_each_connector_iter(connector, &conn_iter) {
237 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
238 DRM_CONNECTOR_POLL_DISCONNECT))
239 poll = true;
240 }
241 drm_connector_list_iter_end(&conn_iter);
242
243 if (dev->mode_config.delayed_event) {
244 /*
245 * FIXME:
246 *
247 * Use short (1s) delay to handle the initial delayed event.
248 * This delay should not be needed, but Optimus/nouveau will
249 * fail in a mysterious way if the delayed event is handled as
250 * soon as possible like it is done in
251 * drm_helper_probe_single_connector_modes() in case the poll
252 * was enabled before.
253 */
254 poll = true;
255 delay = HZ;
256 }
257
258 if (poll)
259 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
260}
261EXPORT_SYMBOL(drm_kms_helper_poll_enable);
262
263static enum drm_connector_status
264drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
265{
266 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
267 struct drm_modeset_acquire_ctx ctx;
268 int ret;
269
270 drm_modeset_acquire_init(&ctx, 0);
271
272retry:
273 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
274 if (!ret) {
275 if (funcs->detect_ctx)
276 ret = funcs->detect_ctx(connector, &ctx, force);
277 else if (connector->funcs->detect)
278 ret = connector->funcs->detect(connector, force);
279 else
280 ret = connector_status_connected;
281 }
282
283 if (ret == -EDEADLK) {
284 drm_modeset_backoff(&ctx);
285 goto retry;
286 }
287
288 if (WARN_ON(ret < 0))
289 ret = connector_status_unknown;
290
291 drm_modeset_drop_locks(&ctx);
292 drm_modeset_acquire_fini(&ctx);
293
294 return ret;
295}
296
297/**
298 * drm_helper_probe_detect - probe connector status
299 * @connector: connector to probe
300 * @ctx: acquire_ctx, or NULL to let this function handle locking.
301 * @force: Whether destructive probe operations should be performed.
302 *
303 * This function calls the detect callbacks of the connector.
304 * This function returns &drm_connector_status, or
305 * if @ctx is set, it might also return -EDEADLK.
306 */
307int
308drm_helper_probe_detect(struct drm_connector *connector,
309 struct drm_modeset_acquire_ctx *ctx,
310 bool force)
311{
312 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
313 struct drm_device *dev = connector->dev;
314 int ret;
315
316 if (!ctx)
317 return drm_helper_probe_detect_ctx(connector, force);
318
319 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
320 if (ret)
321 return ret;
322
323 if (funcs->detect_ctx)
324 return funcs->detect_ctx(connector, ctx, force);
325 else if (connector->funcs->detect)
326 return connector->funcs->detect(connector, force);
327 else
328 return connector_status_connected;
329}
330EXPORT_SYMBOL(drm_helper_probe_detect);
331
332/**
333 * drm_helper_probe_single_connector_modes - get complete set of display modes
334 * @connector: connector to probe
335 * @maxX: max width for modes
336 * @maxY: max height for modes
337 *
338 * Based on the helper callbacks implemented by @connector in struct
339 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
340 * be added to the connector's probed_modes list, then culled (based on validity
341 * and the @maxX, @maxY parameters) and put into the normal modes list.
342 *
343 * Intended to be used as a generic implementation of the
344 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
345 * for output mode filtering and detection.
346 *
347 * The basic procedure is as follows
348 *
349 * 1. All modes currently on the connector's modes list are marked as stale
350 *
351 * 2. New modes are added to the connector's probed_modes list with
352 * drm_mode_probed_add(). New modes start their life with status as OK.
353 * Modes are added from a single source using the following priority order.
354 *
355 * - &drm_connector_helper_funcs.get_modes vfunc
356 * - if the connector status is connector_status_connected, standard
357 * VESA DMT modes up to 1024x768 are automatically added
358 * (drm_add_modes_noedid())
359 *
360 * Finally modes specified via the kernel command line (video=...) are
361 * added in addition to what the earlier probes produced
362 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
363 * using the VESA GTF/CVT formulas.
364 *
365 * 3. Modes are moved from the probed_modes list to the modes list. Potential
366 * duplicates are merged together (see drm_mode_connector_list_update()).
367 * After this step the probed_modes list will be empty again.
368 *
369 * 4. Any non-stale mode on the modes list then undergoes validation
370 *
371 * - drm_mode_validate_basic() performs basic sanity checks
372 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
373 * (if specified)
374 * - drm_mode_validate_flag() checks the modes against basic connector
375 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
376 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform
377 * driver and/or sink specific checks
378 * - the optional &drm_crtc_helper_funcs.mode_valid,
379 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
380 * helpers can perform driver and/or source specific checks which are also
381 * enforced by the modeset/atomic helpers
382 *
383 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
384 * accompanied by a debug message indicating the reason for the mode's
385 * rejection (see drm_mode_prune_invalid()).
386 *
387 * Returns:
388 * The number of modes found on @connector.
389 */
390int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
391 uint32_t maxX, uint32_t maxY)
392{
393 struct drm_device *dev = connector->dev;
394 struct drm_display_mode *mode;
395 const struct drm_connector_helper_funcs *connector_funcs =
396 connector->helper_private;
397 int count = 0, ret;
398 int mode_flags = 0;
399 bool verbose_prune = true;
400 enum drm_connector_status old_status;
401 struct drm_modeset_acquire_ctx ctx;
402
403 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
404
405 drm_modeset_acquire_init(&ctx, 0);
406
407 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
408 connector->name);
409
410retry:
411 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
412 if (ret == -EDEADLK) {
413 drm_modeset_backoff(&ctx);
414 goto retry;
415 } else
416 WARN_ON(ret < 0);
417
418 /* set all old modes to the stale state */
419 list_for_each_entry(mode, &connector->modes, head)
420 mode->status = MODE_STALE;
421
422 old_status = connector->status;
423
424 if (connector->force) {
425 if (connector->force == DRM_FORCE_ON ||
426 connector->force == DRM_FORCE_ON_DIGITAL)
427 connector->status = connector_status_connected;
428 else
429 connector->status = connector_status_disconnected;
430 if (connector->funcs->force)
431 connector->funcs->force(connector);
432 } else {
433 ret = drm_helper_probe_detect(connector, &ctx, true);
434
435 if (ret == -EDEADLK) {
436 drm_modeset_backoff(&ctx);
437 goto retry;
438 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
439 ret = connector_status_unknown;
440
441 connector->status = ret;
442 }
443
444 /*
445 * Normally either the driver's hpd code or the poll loop should
446 * pick up any changes and fire the hotplug event. But if
447 * userspace sneaks in a probe, we might miss a change. Hence
448 * check here, and if anything changed start the hotplug code.
449 */
450 if (old_status != connector->status) {
451 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
452 connector->base.id,
453 connector->name,
454 drm_get_connector_status_name(old_status),
455 drm_get_connector_status_name(connector->status));
456
457 /*
458 * The hotplug event code might call into the fb
459 * helpers, and so expects that we do not hold any
460 * locks. Fire up the poll struct instead, it will
461 * disable itself again.
462 */
463 dev->mode_config.delayed_event = true;
464 if (dev->mode_config.poll_enabled)
465 schedule_delayed_work(&dev->mode_config.output_poll_work,
466 0);
467 }
468
469 /* Re-enable polling in case the global poll config changed. */
470 if (drm_kms_helper_poll != dev->mode_config.poll_running)
471 drm_kms_helper_poll_enable(dev);
472
473 dev->mode_config.poll_running = drm_kms_helper_poll;
474
475 if (connector->status == connector_status_disconnected) {
476 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
477 connector->base.id, connector->name);
478 drm_mode_connector_update_edid_property(connector, NULL);
479 verbose_prune = false;
480 goto prune;
481 }
482
483 count = (*connector_funcs->get_modes)(connector);
484
485 if (count == 0 && connector->status == connector_status_connected)
486 count = drm_add_modes_noedid(connector, 1024, 768);
487 count += drm_helper_probe_add_cmdline_mode(connector);
488 if (count == 0)
489 goto prune;
490
491 drm_mode_connector_list_update(connector);
492
493 if (connector->interlace_allowed)
494 mode_flags |= DRM_MODE_FLAG_INTERLACE;
495 if (connector->doublescan_allowed)
496 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
497 if (connector->stereo_allowed)
498 mode_flags |= DRM_MODE_FLAG_3D_MASK;
499
500 list_for_each_entry(mode, &connector->modes, head) {
501 if (mode->status == MODE_OK)
502 mode->status = drm_mode_validate_driver(dev, mode);
503
504 if (mode->status == MODE_OK)
505 mode->status = drm_mode_validate_size(mode, maxX, maxY);
506
507 if (mode->status == MODE_OK)
508 mode->status = drm_mode_validate_flag(mode, mode_flags);
509
510 if (mode->status == MODE_OK)
511 mode->status = drm_mode_validate_pipeline(mode,
512 connector);
513
514 if (mode->status == MODE_OK)
515 mode->status = drm_mode_validate_ycbcr420(mode,
516 connector);
517 }
518
519prune:
520 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
521
522 drm_modeset_drop_locks(&ctx);
523 drm_modeset_acquire_fini(&ctx);
524
525 if (list_empty(&connector->modes))
526 return 0;
527
528 list_for_each_entry(mode, &connector->modes, head)
529 mode->vrefresh = drm_mode_vrefresh(mode);
530
531 drm_mode_sort(&connector->modes);
532
533 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
534 connector->name);
535 list_for_each_entry(mode, &connector->modes, head) {
536 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
537 drm_mode_debug_printmodeline(mode);
538 }
539
540 return count;
541}
542EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
543
544/**
545 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
546 * @dev: drm_device whose connector state changed
547 *
548 * This function fires off the uevent for userspace and also calls the
549 * output_poll_changed function, which is most commonly used to inform the fbdev
550 * emulation code and allow it to update the fbcon output configuration.
551 *
552 * Drivers should call this from their hotplug handling code when a change is
553 * detected. Note that this function does not do any output detection of its
554 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
555 * driver already.
556 *
557 * This function must be called from process context with no mode
558 * setting locks held.
559 */
560void drm_kms_helper_hotplug_event(struct drm_device *dev)
561{
562 /* send a uevent + call fbdev */
563 drm_sysfs_hotplug_event(dev);
564 if (dev->mode_config.funcs->output_poll_changed)
565 dev->mode_config.funcs->output_poll_changed(dev);
566}
567EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
568
569static void output_poll_execute(struct work_struct *work)
570{
571 struct delayed_work *delayed_work = to_delayed_work(work);
572 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
573 struct drm_connector *connector;
574 struct drm_connector_list_iter conn_iter;
575 enum drm_connector_status old_status;
576 bool repoll = false, changed;
577
578 /* Pick up any changes detected by the probe functions. */
579 changed = dev->mode_config.delayed_event;
580 dev->mode_config.delayed_event = false;
581
582 if (!drm_kms_helper_poll)
583 goto out;
584
585 if (!mutex_trylock(&dev->mode_config.mutex)) {
586 repoll = true;
587 goto out;
588 }
589
590 drm_connector_list_iter_begin(dev, &conn_iter);
591 drm_for_each_connector_iter(connector, &conn_iter) {
592 /* Ignore forced connectors. */
593 if (connector->force)
594 continue;
595
596 /* Ignore HPD capable connectors and connectors where we don't
597 * want any hotplug detection at all for polling. */
598 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
599 continue;
600
601 old_status = connector->status;
602 /* if we are connected and don't want to poll for disconnect
603 skip it */
604 if (old_status == connector_status_connected &&
605 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
606 continue;
607
608 repoll = true;
609
610 connector->status = drm_helper_probe_detect(connector, NULL, false);
611 if (old_status != connector->status) {
612 const char *old, *new;
613
614 /*
615 * The poll work sets force=false when calling detect so
616 * that drivers can avoid to do disruptive tests (e.g.
617 * when load detect cycles could cause flickering on
618 * other, running displays). This bears the risk that we
619 * flip-flop between unknown here in the poll work and
620 * the real state when userspace forces a full detect
621 * call after receiving a hotplug event due to this
622 * change.
623 *
624 * Hence clamp an unknown detect status to the old
625 * value.
626 */
627 if (connector->status == connector_status_unknown) {
628 connector->status = old_status;
629 continue;
630 }
631
632 old = drm_get_connector_status_name(old_status);
633 new = drm_get_connector_status_name(connector->status);
634
635 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
636 "status updated from %s to %s\n",
637 connector->base.id,
638 connector->name,
639 old, new);
640
641 changed = true;
642 }
643 }
644 drm_connector_list_iter_end(&conn_iter);
645
646 mutex_unlock(&dev->mode_config.mutex);
647
648out:
649 if (changed)
650 drm_kms_helper_hotplug_event(dev);
651
652 if (repoll)
653 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
654}
655
656/**
657 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
658 *
659 * Determine if %current task is an output poll worker. This can be used
660 * to select distinct code paths for output polling versus other contexts.
661 *
662 * One use case is to avoid a deadlock between the output poll worker and
663 * the autosuspend worker wherein the latter waits for polling to finish
664 * upon calling drm_kms_helper_poll_disable(), while the former waits for
665 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
666 * connector ->detect hook.
667 */
668bool drm_kms_helper_is_poll_worker(void)
669{
670 struct work_struct *work = current_work();
671
672 return work && work->func == output_poll_execute;
673}
674EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
675
676/**
677 * drm_kms_helper_poll_disable - disable output polling
678 * @dev: drm_device
679 *
680 * This function disables the output polling work.
681 *
682 * Drivers can call this helper from their device suspend implementation. It is
683 * not an error to call this even when output polling isn't enabled or already
684 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
685 *
686 * Note that calls to enable and disable polling must be strictly ordered, which
687 * is automatically the case when they're only call from suspend/resume
688 * callbacks.
689 */
690void drm_kms_helper_poll_disable(struct drm_device *dev)
691{
692 if (!dev->mode_config.poll_enabled)
693 return;
694 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
695}
696EXPORT_SYMBOL(drm_kms_helper_poll_disable);
697
698/**
699 * drm_kms_helper_poll_init - initialize and enable output polling
700 * @dev: drm_device
701 *
702 * This function intializes and then also enables output polling support for
703 * @dev. Drivers which do not have reliable hotplug support in hardware can use
704 * this helper infrastructure to regularly poll such connectors for changes in
705 * their connection state.
706 *
707 * Drivers can control which connectors are polled by setting the
708 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
709 * connectors where probing live outputs can result in visual distortion drivers
710 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
711 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
712 * completely ignored by the polling logic.
713 *
714 * Note that a connector can be both polled and probed from the hotplug handler,
715 * in case the hotplug interrupt is known to be unreliable.
716 */
717void drm_kms_helper_poll_init(struct drm_device *dev)
718{
719 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
720 dev->mode_config.poll_enabled = true;
721
722 drm_kms_helper_poll_enable(dev);
723}
724EXPORT_SYMBOL(drm_kms_helper_poll_init);
725
726/**
727 * drm_kms_helper_poll_fini - disable output polling and clean it up
728 * @dev: drm_device
729 */
730void drm_kms_helper_poll_fini(struct drm_device *dev)
731{
732 drm_kms_helper_poll_disable(dev);
733}
734EXPORT_SYMBOL(drm_kms_helper_poll_fini);
735
736/**
737 * drm_helper_hpd_irq_event - hotplug processing
738 * @dev: drm_device
739 *
740 * Drivers can use this helper function to run a detect cycle on all connectors
741 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
742 * other connectors are ignored, which is useful to avoid reprobing fixed
743 * panels.
744 *
745 * This helper function is useful for drivers which can't or don't track hotplug
746 * interrupts for each connector.
747 *
748 * Drivers which support hotplug interrupts for each connector individually and
749 * which have a more fine-grained detect logic should bypass this code and
750 * directly call drm_kms_helper_hotplug_event() in case the connector state
751 * changed.
752 *
753 * This function must be called from process context with no mode
754 * setting locks held.
755 *
756 * Note that a connector can be both polled and probed from the hotplug handler,
757 * in case the hotplug interrupt is known to be unreliable.
758 */
759bool drm_helper_hpd_irq_event(struct drm_device *dev)
760{
761 struct drm_connector *connector;
762 struct drm_connector_list_iter conn_iter;
763 enum drm_connector_status old_status;
764 bool changed = false;
765
766 if (!dev->mode_config.poll_enabled)
767 return false;
768
769 mutex_lock(&dev->mode_config.mutex);
770 drm_connector_list_iter_begin(dev, &conn_iter);
771 drm_for_each_connector_iter(connector, &conn_iter) {
772 /* Only handle HPD capable connectors. */
773 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
774 continue;
775
776 old_status = connector->status;
777
778 connector->status = drm_helper_probe_detect(connector, NULL, false);
779 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
780 connector->base.id,
781 connector->name,
782 drm_get_connector_status_name(old_status),
783 drm_get_connector_status_name(connector->status));
784 if (old_status != connector->status)
785 changed = true;
786 }
787 drm_connector_list_iter_end(&conn_iter);
788 mutex_unlock(&dev->mode_config.mutex);
789
790 if (changed)
791 drm_kms_helper_hotplug_event(dev);
792
793 return changed;
794}
795EXPORT_SYMBOL(drm_helper_hpd_irq_event);
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
61static bool drm_kms_helper_poll = true;
62module_param_named(poll, drm_kms_helper_poll, bool, 0600);
63
64static enum drm_mode_status
65drm_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
83static 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_locked - re-enable output polling.
119 * @dev: drm_device
120 *
121 * This function re-enables the output polling work without
122 * locking the mode_config mutex.
123 *
124 * This is like drm_kms_helper_poll_enable() however it is to be
125 * called from a context where the mode_config mutex is locked
126 * already.
127 */
128void drm_kms_helper_poll_enable_locked(struct drm_device *dev)
129{
130 bool poll = false;
131 struct drm_connector *connector;
132 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
133
134 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
135
136 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
137 return;
138
139 drm_for_each_connector(connector, dev) {
140 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
141 DRM_CONNECTOR_POLL_DISCONNECT))
142 poll = true;
143 }
144
145 if (dev->mode_config.delayed_event) {
146 /*
147 * FIXME:
148 *
149 * Use short (1s) delay to handle the initial delayed event.
150 * This delay should not be needed, but Optimus/nouveau will
151 * fail in a mysterious way if the delayed event is handled as
152 * soon as possible like it is done in
153 * drm_helper_probe_single_connector_modes() in case the poll
154 * was enabled before.
155 */
156 poll = true;
157 delay = HZ;
158 }
159
160 if (poll)
161 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
162}
163EXPORT_SYMBOL(drm_kms_helper_poll_enable_locked);
164
165static enum drm_connector_status
166drm_connector_detect(struct drm_connector *connector, bool force)
167{
168 return connector->funcs->detect ?
169 connector->funcs->detect(connector, force) :
170 connector_status_connected;
171}
172
173/**
174 * drm_helper_probe_single_connector_modes - get complete set of display modes
175 * @connector: connector to probe
176 * @maxX: max width for modes
177 * @maxY: max height for modes
178 *
179 * Based on the helper callbacks implemented by @connector in struct
180 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
181 * be added to the connector's probed_modes list, then culled (based on validity
182 * and the @maxX, @maxY parameters) and put into the normal modes list.
183 *
184 * Intended to be used as a generic implementation of the ->fill_modes()
185 * @connector vfunc for drivers that use the CRTC helpers for output mode
186 * filtering and detection.
187 *
188 * The basic procedure is as follows
189 *
190 * 1. All modes currently on the connector's modes list are marked as stale
191 *
192 * 2. New modes are added to the connector's probed_modes list with
193 * drm_mode_probed_add(). New modes start their life with status as OK.
194 * Modes are added from a single source using the following priority order.
195 *
196 * - debugfs 'override_edid' (used for testing only)
197 * - firmware EDID (drm_load_edid_firmware())
198 * - connector helper ->get_modes() vfunc
199 * - if the connector status is connector_status_connected, standard
200 * VESA DMT modes up to 1024x768 are automatically added
201 * (drm_add_modes_noedid())
202 *
203 * Finally modes specified via the kernel command line (video=...) are
204 * added in addition to what the earlier probes produced
205 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
206 * using the VESA GTF/CVT formulas.
207 *
208 * 3. Modes are moved from the probed_modes list to the modes list. Potential
209 * duplicates are merged together (see drm_mode_connector_list_update()).
210 * After this step the probed_modes list will be empty again.
211 *
212 * 4. Any non-stale mode on the modes list then undergoes validation
213 *
214 * - drm_mode_validate_basic() performs basic sanity checks
215 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
216 * (if specified)
217 * - drm_mode_validate_flag() checks the modes againt basic connector
218 * capabilites (interlace_allowed,doublescan_allowed,stereo_allowed)
219 * - the optional connector ->mode_valid() helper can perform driver and/or
220 * hardware specific checks
221 *
222 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
223 * accompanied by a debug message indicating the reason for the mode's
224 * rejection (see drm_mode_prune_invalid()).
225 *
226 * Returns:
227 * The number of modes found on @connector.
228 */
229int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
230 uint32_t maxX, uint32_t maxY)
231{
232 struct drm_device *dev = connector->dev;
233 struct drm_display_mode *mode;
234 const struct drm_connector_helper_funcs *connector_funcs =
235 connector->helper_private;
236 int count = 0;
237 int mode_flags = 0;
238 bool verbose_prune = true;
239 enum drm_connector_status old_status;
240
241 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
242
243 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
244 connector->name);
245 /* set all old modes to the stale state */
246 list_for_each_entry(mode, &connector->modes, head)
247 mode->status = MODE_STALE;
248
249 old_status = connector->status;
250
251 if (connector->force) {
252 if (connector->force == DRM_FORCE_ON ||
253 connector->force == DRM_FORCE_ON_DIGITAL)
254 connector->status = connector_status_connected;
255 else
256 connector->status = connector_status_disconnected;
257 if (connector->funcs->force)
258 connector->funcs->force(connector);
259 } else {
260 connector->status = drm_connector_detect(connector, true);
261 }
262
263 /*
264 * Normally either the driver's hpd code or the poll loop should
265 * pick up any changes and fire the hotplug event. But if
266 * userspace sneaks in a probe, we might miss a change. Hence
267 * check here, and if anything changed start the hotplug code.
268 */
269 if (old_status != connector->status) {
270 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
271 connector->base.id,
272 connector->name,
273 drm_get_connector_status_name(old_status),
274 drm_get_connector_status_name(connector->status));
275
276 /*
277 * The hotplug event code might call into the fb
278 * helpers, and so expects that we do not hold any
279 * locks. Fire up the poll struct instead, it will
280 * disable itself again.
281 */
282 dev->mode_config.delayed_event = true;
283 if (dev->mode_config.poll_enabled)
284 schedule_delayed_work(&dev->mode_config.output_poll_work,
285 0);
286 }
287
288 /* Re-enable polling in case the global poll config changed. */
289 if (drm_kms_helper_poll != dev->mode_config.poll_running)
290 drm_kms_helper_poll_enable_locked(dev);
291
292 dev->mode_config.poll_running = drm_kms_helper_poll;
293
294 if (connector->status == connector_status_disconnected) {
295 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
296 connector->base.id, connector->name);
297 drm_mode_connector_update_edid_property(connector, NULL);
298 verbose_prune = false;
299 goto prune;
300 }
301
302 if (connector->override_edid) {
303 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
304
305 count = drm_add_edid_modes(connector, edid);
306 drm_edid_to_eld(connector, edid);
307 } else {
308 count = drm_load_edid_firmware(connector);
309 if (count == 0)
310 count = (*connector_funcs->get_modes)(connector);
311 }
312
313 if (count == 0 && connector->status == connector_status_connected)
314 count = drm_add_modes_noedid(connector, 1024, 768);
315 count += drm_helper_probe_add_cmdline_mode(connector);
316 if (count == 0)
317 goto prune;
318
319 drm_mode_connector_list_update(connector);
320
321 if (connector->interlace_allowed)
322 mode_flags |= DRM_MODE_FLAG_INTERLACE;
323 if (connector->doublescan_allowed)
324 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
325 if (connector->stereo_allowed)
326 mode_flags |= DRM_MODE_FLAG_3D_MASK;
327
328 list_for_each_entry(mode, &connector->modes, head) {
329 if (mode->status == MODE_OK)
330 mode->status = drm_mode_validate_basic(mode);
331
332 if (mode->status == MODE_OK)
333 mode->status = drm_mode_validate_size(mode, maxX, maxY);
334
335 if (mode->status == MODE_OK)
336 mode->status = drm_mode_validate_flag(mode, mode_flags);
337
338 if (mode->status == MODE_OK && connector_funcs->mode_valid)
339 mode->status = connector_funcs->mode_valid(connector,
340 mode);
341 }
342
343prune:
344 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
345
346 if (list_empty(&connector->modes))
347 return 0;
348
349 list_for_each_entry(mode, &connector->modes, head)
350 mode->vrefresh = drm_mode_vrefresh(mode);
351
352 drm_mode_sort(&connector->modes);
353
354 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
355 connector->name);
356 list_for_each_entry(mode, &connector->modes, head) {
357 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
358 drm_mode_debug_printmodeline(mode);
359 }
360
361 return count;
362}
363EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
364
365/**
366 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
367 * @dev: drm_device whose connector state changed
368 *
369 * This function fires off the uevent for userspace and also calls the
370 * output_poll_changed function, which is most commonly used to inform the fbdev
371 * emulation code and allow it to update the fbcon output configuration.
372 *
373 * Drivers should call this from their hotplug handling code when a change is
374 * detected. Note that this function does not do any output detection of its
375 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
376 * driver already.
377 *
378 * This function must be called from process context with no mode
379 * setting locks held.
380 */
381void drm_kms_helper_hotplug_event(struct drm_device *dev)
382{
383 /* send a uevent + call fbdev */
384 drm_sysfs_hotplug_event(dev);
385 if (dev->mode_config.funcs->output_poll_changed)
386 dev->mode_config.funcs->output_poll_changed(dev);
387}
388EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
389
390static void output_poll_execute(struct work_struct *work)
391{
392 struct delayed_work *delayed_work = to_delayed_work(work);
393 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
394 struct drm_connector *connector;
395 enum drm_connector_status old_status;
396 bool repoll = false, changed;
397
398 /* Pick up any changes detected by the probe functions. */
399 changed = dev->mode_config.delayed_event;
400 dev->mode_config.delayed_event = false;
401
402 if (!drm_kms_helper_poll)
403 goto out;
404
405 if (!mutex_trylock(&dev->mode_config.mutex)) {
406 repoll = true;
407 goto out;
408 }
409
410 drm_for_each_connector(connector, dev) {
411
412 /* Ignore forced connectors. */
413 if (connector->force)
414 continue;
415
416 /* Ignore HPD capable connectors and connectors where we don't
417 * want any hotplug detection at all for polling. */
418 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
419 continue;
420
421 old_status = connector->status;
422 /* if we are connected and don't want to poll for disconnect
423 skip it */
424 if (old_status == connector_status_connected &&
425 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
426 continue;
427
428 repoll = true;
429
430 connector->status = drm_connector_detect(connector, false);
431 if (old_status != connector->status) {
432 const char *old, *new;
433
434 /*
435 * The poll work sets force=false when calling detect so
436 * that drivers can avoid to do disruptive tests (e.g.
437 * when load detect cycles could cause flickering on
438 * other, running displays). This bears the risk that we
439 * flip-flop between unknown here in the poll work and
440 * the real state when userspace forces a full detect
441 * call after receiving a hotplug event due to this
442 * change.
443 *
444 * Hence clamp an unknown detect status to the old
445 * value.
446 */
447 if (connector->status == connector_status_unknown) {
448 connector->status = old_status;
449 continue;
450 }
451
452 old = drm_get_connector_status_name(old_status);
453 new = drm_get_connector_status_name(connector->status);
454
455 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
456 "status updated from %s to %s\n",
457 connector->base.id,
458 connector->name,
459 old, new);
460
461 changed = true;
462 }
463 }
464
465 mutex_unlock(&dev->mode_config.mutex);
466
467out:
468 if (changed)
469 drm_kms_helper_hotplug_event(dev);
470
471 if (repoll)
472 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
473}
474
475/**
476 * drm_kms_helper_poll_disable - disable output polling
477 * @dev: drm_device
478 *
479 * This function disables the output polling work.
480 *
481 * Drivers can call this helper from their device suspend implementation. It is
482 * not an error to call this even when output polling isn't enabled or arlready
483 * disabled.
484 */
485void drm_kms_helper_poll_disable(struct drm_device *dev)
486{
487 if (!dev->mode_config.poll_enabled)
488 return;
489 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
490}
491EXPORT_SYMBOL(drm_kms_helper_poll_disable);
492
493/**
494 * drm_kms_helper_poll_enable - re-enable output polling.
495 * @dev: drm_device
496 *
497 * This function re-enables the output polling work.
498 *
499 * Drivers can call this helper from their device resume implementation. It is
500 * an error to call this when the output polling support has not yet been set
501 * up.
502 */
503void drm_kms_helper_poll_enable(struct drm_device *dev)
504{
505 mutex_lock(&dev->mode_config.mutex);
506 drm_kms_helper_poll_enable_locked(dev);
507 mutex_unlock(&dev->mode_config.mutex);
508}
509EXPORT_SYMBOL(drm_kms_helper_poll_enable);
510
511/**
512 * drm_kms_helper_poll_init - initialize and enable output polling
513 * @dev: drm_device
514 *
515 * This function intializes and then also enables output polling support for
516 * @dev. Drivers which do not have reliable hotplug support in hardware can use
517 * this helper infrastructure to regularly poll such connectors for changes in
518 * their connection state.
519 *
520 * Drivers can control which connectors are polled by setting the
521 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
522 * connectors where probing live outputs can result in visual distortion drivers
523 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
524 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
525 * completely ignored by the polling logic.
526 *
527 * Note that a connector can be both polled and probed from the hotplug handler,
528 * in case the hotplug interrupt is known to be unreliable.
529 */
530void drm_kms_helper_poll_init(struct drm_device *dev)
531{
532 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
533 dev->mode_config.poll_enabled = true;
534
535 drm_kms_helper_poll_enable(dev);
536}
537EXPORT_SYMBOL(drm_kms_helper_poll_init);
538
539/**
540 * drm_kms_helper_poll_fini - disable output polling and clean it up
541 * @dev: drm_device
542 */
543void drm_kms_helper_poll_fini(struct drm_device *dev)
544{
545 drm_kms_helper_poll_disable(dev);
546}
547EXPORT_SYMBOL(drm_kms_helper_poll_fini);
548
549/**
550 * drm_helper_hpd_irq_event - hotplug processing
551 * @dev: drm_device
552 *
553 * Drivers can use this helper function to run a detect cycle on all connectors
554 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
555 * other connectors are ignored, which is useful to avoid reprobing fixed
556 * panels.
557 *
558 * This helper function is useful for drivers which can't or don't track hotplug
559 * interrupts for each connector.
560 *
561 * Drivers which support hotplug interrupts for each connector individually and
562 * which have a more fine-grained detect logic should bypass this code and
563 * directly call drm_kms_helper_hotplug_event() in case the connector state
564 * changed.
565 *
566 * This function must be called from process context with no mode
567 * setting locks held.
568 *
569 * Note that a connector can be both polled and probed from the hotplug handler,
570 * in case the hotplug interrupt is known to be unreliable.
571 */
572bool drm_helper_hpd_irq_event(struct drm_device *dev)
573{
574 struct drm_connector *connector;
575 enum drm_connector_status old_status;
576 bool changed = false;
577
578 if (!dev->mode_config.poll_enabled)
579 return false;
580
581 mutex_lock(&dev->mode_config.mutex);
582 drm_for_each_connector(connector, dev) {
583
584 /* Only handle HPD capable connectors. */
585 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
586 continue;
587
588 old_status = connector->status;
589
590 connector->status = drm_connector_detect(connector, false);
591 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
592 connector->base.id,
593 connector->name,
594 drm_get_connector_status_name(old_status),
595 drm_get_connector_status_name(connector->status));
596 if (old_status != connector->status)
597 changed = true;
598 }
599
600 mutex_unlock(&dev->mode_config.mutex);
601
602 if (changed)
603 drm_kms_helper_hotplug_event(dev);
604
605 return changed;
606}
607EXPORT_SYMBOL(drm_helper_hpd_irq_event);