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_event.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_edid.h>
39 #include <drm/drm_fourcc.h>
40 #include <drm/drm_managed.h>
41 #include <drm/drm_modeset_helper_vtables.h>
42 #include <drm/drm_print.h>
43 #include <drm/drm_probe_helper.h>
44 #include <drm/drm_sysfs.h>
46 #include "drm_crtc_helper_internal.h"
49 * DOC: output probing helper overview
51 * This library provides some helper code for output probing. It provides an
52 * implementation of the core &drm_connector_funcs.fill_modes interface with
53 * drm_helper_probe_single_connector_modes().
55 * It also provides support for polling connectors with a work item and for
56 * generic hotplug interrupt handling where the driver doesn't or cannot keep
57 * track of a per-connector hpd interrupt.
59 * This helper library can be used independently of the modeset helper library.
60 * Drivers can also overwrite different parts e.g. use their own hotplug
61 * handling code to avoid probing unrelated outputs.
63 * The probe helpers share the function table structures with other display
64 * helper libraries. See &struct drm_connector_helper_funcs for the details.
67 static bool drm_kms_helper_poll
= true;
68 module_param_named(poll
, drm_kms_helper_poll
, bool, 0600);
70 static enum drm_mode_status
71 drm_mode_validate_flag(const struct drm_display_mode
*mode
,
74 if ((mode
->flags
& DRM_MODE_FLAG_INTERLACE
) &&
75 !(flags
& DRM_MODE_FLAG_INTERLACE
))
76 return MODE_NO_INTERLACE
;
78 if ((mode
->flags
& DRM_MODE_FLAG_DBLSCAN
) &&
79 !(flags
& DRM_MODE_FLAG_DBLSCAN
))
80 return MODE_NO_DBLESCAN
;
82 if ((mode
->flags
& DRM_MODE_FLAG_3D_MASK
) &&
83 !(flags
& DRM_MODE_FLAG_3D_MASK
))
84 return MODE_NO_STEREO
;
90 drm_mode_validate_pipeline(struct drm_display_mode
*mode
,
91 struct drm_connector
*connector
,
92 struct drm_modeset_acquire_ctx
*ctx
,
93 enum drm_mode_status
*status
)
95 struct drm_device
*dev
= connector
->dev
;
96 struct drm_encoder
*encoder
;
99 /* Step 1: Validate against connector */
100 ret
= drm_connector_mode_valid(connector
, mode
, ctx
, status
);
101 if (ret
|| *status
!= MODE_OK
)
104 /* Step 2: Validate against encoders and crtcs */
105 drm_connector_for_each_possible_encoder(connector
, encoder
) {
106 struct drm_bridge
*bridge
;
107 struct drm_crtc
*crtc
;
109 *status
= drm_encoder_mode_valid(encoder
, mode
);
110 if (*status
!= MODE_OK
) {
111 /* No point in continuing for crtc check as this encoder
112 * will not accept the mode anyway. If all encoders
113 * reject the mode then, at exit, ret will not be
118 bridge
= drm_bridge_chain_get_first_bridge(encoder
);
119 *status
= drm_bridge_chain_mode_valid(bridge
,
120 &connector
->display_info
,
122 if (*status
!= MODE_OK
) {
123 /* There is also no point in continuing for crtc check
128 drm_for_each_crtc(crtc
, dev
) {
129 if (!drm_encoder_crtc_ok(encoder
, crtc
))
132 *status
= drm_crtc_mode_valid(crtc
, mode
);
133 if (*status
== MODE_OK
) {
134 /* If we get to this point there is at least
135 * one combination of encoder+crtc that works
136 * for this mode. Lets return now. */
145 static int drm_helper_probe_add_cmdline_mode(struct drm_connector
*connector
)
147 struct drm_cmdline_mode
*cmdline_mode
;
148 struct drm_display_mode
*mode
;
150 cmdline_mode
= &connector
->cmdline_mode
;
151 if (!cmdline_mode
->specified
)
154 /* Only add a GTF mode if we find no matching probed modes */
155 list_for_each_entry(mode
, &connector
->probed_modes
, head
) {
156 if (mode
->hdisplay
!= cmdline_mode
->xres
||
157 mode
->vdisplay
!= cmdline_mode
->yres
)
160 if (cmdline_mode
->refresh_specified
) {
161 /* The probed mode's vrefresh is set until later */
162 if (drm_mode_vrefresh(mode
) != cmdline_mode
->refresh
)
166 /* Mark the matching mode as being preferred by the user */
167 mode
->type
|= DRM_MODE_TYPE_USERDEF
;
171 mode
= drm_mode_create_from_cmdline_mode(connector
->dev
,
176 drm_mode_probed_add(connector
, mode
);
180 enum drm_mode_status
drm_crtc_mode_valid(struct drm_crtc
*crtc
,
181 const struct drm_display_mode
*mode
)
183 const struct drm_crtc_helper_funcs
*crtc_funcs
= crtc
->helper_private
;
185 if (!crtc_funcs
|| !crtc_funcs
->mode_valid
)
188 return crtc_funcs
->mode_valid(crtc
, mode
);
191 enum drm_mode_status
drm_encoder_mode_valid(struct drm_encoder
*encoder
,
192 const struct drm_display_mode
*mode
)
194 const struct drm_encoder_helper_funcs
*encoder_funcs
=
195 encoder
->helper_private
;
197 if (!encoder_funcs
|| !encoder_funcs
->mode_valid
)
200 return encoder_funcs
->mode_valid(encoder
, mode
);
204 drm_connector_mode_valid(struct drm_connector
*connector
,
205 struct drm_display_mode
*mode
,
206 struct drm_modeset_acquire_ctx
*ctx
,
207 enum drm_mode_status
*status
)
209 const struct drm_connector_helper_funcs
*connector_funcs
=
210 connector
->helper_private
;
213 if (!connector_funcs
)
215 else if (connector_funcs
->mode_valid_ctx
)
216 ret
= connector_funcs
->mode_valid_ctx(connector
, mode
, ctx
,
218 else if (connector_funcs
->mode_valid
)
219 *status
= connector_funcs
->mode_valid(connector
, mode
);
226 static void drm_kms_helper_disable_hpd(struct drm_device
*dev
)
228 struct drm_connector
*connector
;
229 struct drm_connector_list_iter conn_iter
;
231 drm_connector_list_iter_begin(dev
, &conn_iter
);
232 drm_for_each_connector_iter(connector
, &conn_iter
) {
233 const struct drm_connector_helper_funcs
*funcs
=
234 connector
->helper_private
;
236 if (funcs
&& funcs
->disable_hpd
)
237 funcs
->disable_hpd(connector
);
239 drm_connector_list_iter_end(&conn_iter
);
242 static bool drm_kms_helper_enable_hpd(struct drm_device
*dev
)
245 struct drm_connector
*connector
;
246 struct drm_connector_list_iter conn_iter
;
248 drm_connector_list_iter_begin(dev
, &conn_iter
);
249 drm_for_each_connector_iter(connector
, &conn_iter
) {
250 const struct drm_connector_helper_funcs
*funcs
=
251 connector
->helper_private
;
253 if (funcs
&& funcs
->enable_hpd
)
254 funcs
->enable_hpd(connector
);
256 if (connector
->polled
& (DRM_CONNECTOR_POLL_CONNECT
|
257 DRM_CONNECTOR_POLL_DISCONNECT
))
260 drm_connector_list_iter_end(&conn_iter
);
265 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
266 static void reschedule_output_poll_work(struct drm_device
*dev
)
268 unsigned long delay
= DRM_OUTPUT_POLL_PERIOD
;
270 if (dev
->mode_config
.delayed_event
)
274 * Use short (1s) delay to handle the initial delayed event.
275 * This delay should not be needed, but Optimus/nouveau will
276 * fail in a mysterious way if the delayed event is handled as
277 * soon as possible like it is done in
278 * drm_helper_probe_single_connector_modes() in case the poll
279 * was enabled before.
283 schedule_delayed_work(&dev
->mode_config
.output_poll_work
, delay
);
287 * drm_kms_helper_poll_enable - re-enable output polling.
290 * This function re-enables the output polling work, after it has been
291 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
294 * Drivers can call this helper from their device resume implementation. It is
295 * not an error to call this even when output polling isn't enabled.
297 * If device polling was never initialized before, this call will trigger a
298 * warning and return.
300 * Note that calls to enable and disable polling must be strictly ordered, which
301 * is automatically the case when they're only call from suspend/resume
304 void drm_kms_helper_poll_enable(struct drm_device
*dev
)
306 if (drm_WARN_ON_ONCE(dev
, !dev
->mode_config
.poll_enabled
) ||
307 !drm_kms_helper_poll
|| dev
->mode_config
.poll_running
)
310 if (drm_kms_helper_enable_hpd(dev
) ||
311 dev
->mode_config
.delayed_event
)
312 reschedule_output_poll_work(dev
);
314 dev
->mode_config
.poll_running
= true;
316 EXPORT_SYMBOL(drm_kms_helper_poll_enable
);
319 * drm_kms_helper_poll_reschedule - reschedule the output polling work
322 * This function reschedules the output polling work, after polling for a
323 * connector has been enabled.
325 * Drivers must call this helper after enabling polling for a connector by
326 * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
327 * in drm_connector::polled. Note that after disabling polling by clearing these
328 * flags for a connector will stop the output polling work automatically if
329 * the polling is disabled for all other connectors as well.
331 * The function can be called only after polling has been enabled by calling
332 * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
334 void drm_kms_helper_poll_reschedule(struct drm_device
*dev
)
336 if (dev
->mode_config
.poll_running
)
337 reschedule_output_poll_work(dev
);
339 EXPORT_SYMBOL(drm_kms_helper_poll_reschedule
);
341 static enum drm_connector_status
342 drm_helper_probe_detect_ctx(struct drm_connector
*connector
, bool force
)
344 const struct drm_connector_helper_funcs
*funcs
= connector
->helper_private
;
345 struct drm_modeset_acquire_ctx ctx
;
348 drm_modeset_acquire_init(&ctx
, 0);
351 ret
= drm_modeset_lock(&connector
->dev
->mode_config
.connection_mutex
, &ctx
);
353 if (funcs
->detect_ctx
)
354 ret
= funcs
->detect_ctx(connector
, &ctx
, force
);
355 else if (connector
->funcs
->detect
)
356 ret
= connector
->funcs
->detect(connector
, force
);
358 ret
= connector_status_connected
;
361 if (ret
== -EDEADLK
) {
362 drm_modeset_backoff(&ctx
);
366 if (WARN_ON(ret
< 0))
367 ret
= connector_status_unknown
;
369 if (ret
!= connector
->status
)
370 connector
->epoch_counter
+= 1;
372 drm_modeset_drop_locks(&ctx
);
373 drm_modeset_acquire_fini(&ctx
);
379 * drm_helper_probe_detect - probe connector status
380 * @connector: connector to probe
381 * @ctx: acquire_ctx, or NULL to let this function handle locking.
382 * @force: Whether destructive probe operations should be performed.
384 * This function calls the detect callbacks of the connector.
385 * This function returns &drm_connector_status, or
386 * if @ctx is set, it might also return -EDEADLK.
389 drm_helper_probe_detect(struct drm_connector
*connector
,
390 struct drm_modeset_acquire_ctx
*ctx
,
393 const struct drm_connector_helper_funcs
*funcs
= connector
->helper_private
;
394 struct drm_device
*dev
= connector
->dev
;
398 return drm_helper_probe_detect_ctx(connector
, force
);
400 ret
= drm_modeset_lock(&dev
->mode_config
.connection_mutex
, ctx
);
404 if (funcs
->detect_ctx
)
405 ret
= funcs
->detect_ctx(connector
, ctx
, force
);
406 else if (connector
->funcs
->detect
)
407 ret
= connector
->funcs
->detect(connector
, force
);
409 ret
= connector_status_connected
;
411 if (ret
!= connector
->status
)
412 connector
->epoch_counter
+= 1;
416 EXPORT_SYMBOL(drm_helper_probe_detect
);
418 static int drm_helper_probe_get_modes(struct drm_connector
*connector
)
420 const struct drm_connector_helper_funcs
*connector_funcs
=
421 connector
->helper_private
;
424 count
= connector_funcs
->get_modes(connector
);
426 /* The .get_modes() callback should not return negative values. */
428 drm_err(connector
->dev
, ".get_modes() returned %pe\n",
434 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
435 * override/firmware EDID.
437 if (count
== 0 && connector
->status
== connector_status_connected
)
438 count
= drm_edid_override_connector_update(connector
);
443 static int __drm_helper_update_and_validate(struct drm_connector
*connector
,
444 uint32_t maxX
, uint32_t maxY
,
445 struct drm_modeset_acquire_ctx
*ctx
)
447 struct drm_device
*dev
= connector
->dev
;
448 struct drm_display_mode
*mode
;
452 drm_connector_list_update(connector
);
454 if (connector
->interlace_allowed
)
455 mode_flags
|= DRM_MODE_FLAG_INTERLACE
;
456 if (connector
->doublescan_allowed
)
457 mode_flags
|= DRM_MODE_FLAG_DBLSCAN
;
458 if (connector
->stereo_allowed
)
459 mode_flags
|= DRM_MODE_FLAG_3D_MASK
;
461 list_for_each_entry(mode
, &connector
->modes
, head
) {
462 if (mode
->status
!= MODE_OK
)
465 mode
->status
= drm_mode_validate_driver(dev
, mode
);
466 if (mode
->status
!= MODE_OK
)
469 mode
->status
= drm_mode_validate_size(mode
, maxX
, maxY
);
470 if (mode
->status
!= MODE_OK
)
473 mode
->status
= drm_mode_validate_flag(mode
, mode_flags
);
474 if (mode
->status
!= MODE_OK
)
477 mode
->status
= drm_mode_validate_ycbcr420(mode
, connector
);
478 if (mode
->status
!= MODE_OK
)
481 ret
= drm_mode_validate_pipeline(mode
, connector
, ctx
,
485 "drm_mode_validate_pipeline failed: %d\n",
488 if (drm_WARN_ON_ONCE(dev
, ret
!= -EDEADLK
))
489 mode
->status
= MODE_ERROR
;
499 * drm_helper_probe_single_connector_modes - get complete set of display modes
500 * @connector: connector to probe
501 * @maxX: max width for modes
502 * @maxY: max height for modes
504 * Based on the helper callbacks implemented by @connector in struct
505 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
506 * be added to the connector's probed_modes list, then culled (based on validity
507 * and the @maxX, @maxY parameters) and put into the normal modes list.
509 * Intended to be used as a generic implementation of the
510 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
511 * for output mode filtering and detection.
513 * The basic procedure is as follows
515 * 1. All modes currently on the connector's modes list are marked as stale
517 * 2. New modes are added to the connector's probed_modes list with
518 * drm_mode_probed_add(). New modes start their life with status as OK.
519 * Modes are added from a single source using the following priority order.
521 * - &drm_connector_helper_funcs.get_modes vfunc
522 * - if the connector status is connector_status_connected, standard
523 * VESA DMT modes up to 1024x768 are automatically added
524 * (drm_add_modes_noedid())
526 * Finally modes specified via the kernel command line (video=...) are
527 * added in addition to what the earlier probes produced
528 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
529 * using the VESA GTF/CVT formulas.
531 * 3. Modes are moved from the probed_modes list to the modes list. Potential
532 * duplicates are merged together (see drm_connector_list_update()).
533 * After this step the probed_modes list will be empty again.
535 * 4. Any non-stale mode on the modes list then undergoes validation
537 * - drm_mode_validate_basic() performs basic sanity checks
538 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
540 * - drm_mode_validate_flag() checks the modes against basic connector
541 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
542 * - the optional &drm_connector_helper_funcs.mode_valid or
543 * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
544 * and/or sink specific checks
545 * - the optional &drm_crtc_helper_funcs.mode_valid,
546 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
547 * helpers can perform driver and/or source specific checks which are also
548 * enforced by the modeset/atomic helpers
550 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
551 * accompanied by a debug message indicating the reason for the mode's
552 * rejection (see drm_mode_prune_invalid()).
555 * The number of modes found on @connector.
557 int drm_helper_probe_single_connector_modes(struct drm_connector
*connector
,
558 uint32_t maxX
, uint32_t maxY
)
560 struct drm_device
*dev
= connector
->dev
;
561 struct drm_display_mode
*mode
;
563 enum drm_connector_status old_status
;
564 struct drm_modeset_acquire_ctx ctx
;
566 WARN_ON(!mutex_is_locked(&dev
->mode_config
.mutex
));
568 drm_modeset_acquire_init(&ctx
, 0);
570 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s]\n", connector
->base
.id
,
574 ret
= drm_modeset_lock(&dev
->mode_config
.connection_mutex
, &ctx
);
575 if (ret
== -EDEADLK
) {
576 drm_modeset_backoff(&ctx
);
581 /* set all old modes to the stale state */
582 list_for_each_entry(mode
, &connector
->modes
, head
)
583 mode
->status
= MODE_STALE
;
585 old_status
= connector
->status
;
587 if (connector
->force
) {
588 if (connector
->force
== DRM_FORCE_ON
||
589 connector
->force
== DRM_FORCE_ON_DIGITAL
)
590 connector
->status
= connector_status_connected
;
592 connector
->status
= connector_status_disconnected
;
593 if (connector
->funcs
->force
)
594 connector
->funcs
->force(connector
);
596 ret
= drm_helper_probe_detect(connector
, &ctx
, true);
598 if (ret
== -EDEADLK
) {
599 drm_modeset_backoff(&ctx
);
601 } else if (WARN(ret
< 0, "Invalid return value %i for connector detection\n", ret
))
602 ret
= connector_status_unknown
;
604 connector
->status
= ret
;
608 * Normally either the driver's hpd code or the poll loop should
609 * pick up any changes and fire the hotplug event. But if
610 * userspace sneaks in a probe, we might miss a change. Hence
611 * check here, and if anything changed start the hotplug code.
613 if (old_status
!= connector
->status
) {
614 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
615 connector
->base
.id
, connector
->name
,
616 drm_get_connector_status_name(old_status
),
617 drm_get_connector_status_name(connector
->status
));
620 * The hotplug event code might call into the fb
621 * helpers, and so expects that we do not hold any
622 * locks. Fire up the poll struct instead, it will
623 * disable itself again.
625 dev
->mode_config
.delayed_event
= true;
626 if (dev
->mode_config
.poll_enabled
)
627 mod_delayed_work(system_wq
,
628 &dev
->mode_config
.output_poll_work
,
633 * Re-enable polling in case the global poll config changed but polling
634 * is still initialized.
636 if (dev
->mode_config
.poll_enabled
)
637 drm_kms_helper_poll_enable(dev
);
639 if (connector
->status
== connector_status_disconnected
) {
640 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] disconnected\n",
641 connector
->base
.id
, connector
->name
);
642 drm_connector_update_edid_property(connector
, NULL
);
643 drm_mode_prune_invalid(dev
, &connector
->modes
, false);
647 count
= drm_helper_probe_get_modes(connector
);
649 if (count
== 0 && (connector
->status
== connector_status_connected
||
650 connector
->status
== connector_status_unknown
)) {
651 count
= drm_add_modes_noedid(connector
, 1024, 768);
654 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
655 * Link CTS specifies that 640x480 (the official "failsafe"
656 * mode) needs to be the default if there's no EDID.
658 if (connector
->connector_type
== DRM_MODE_CONNECTOR_DisplayPort
)
659 drm_set_preferred_mode(connector
, 640, 480);
661 count
+= drm_helper_probe_add_cmdline_mode(connector
);
663 ret
= __drm_helper_update_and_validate(connector
, maxX
, maxY
, &ctx
);
664 if (ret
== -EDEADLK
) {
665 drm_modeset_backoff(&ctx
);
670 drm_mode_prune_invalid(dev
, &connector
->modes
, true);
673 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
674 * all detachable sinks shall support 640x480 @60Hz as a fail safe
675 * mode. If all modes were pruned, perhaps because they need more
676 * lanes or a higher pixel clock than available, at least try to add
679 if (list_empty(&connector
->modes
) &&
680 connector
->connector_type
== DRM_MODE_CONNECTOR_DisplayPort
) {
681 count
= drm_add_modes_noedid(connector
, 640, 480);
682 ret
= __drm_helper_update_and_validate(connector
, maxX
, maxY
, &ctx
);
683 if (ret
== -EDEADLK
) {
684 drm_modeset_backoff(&ctx
);
687 drm_mode_prune_invalid(dev
, &connector
->modes
, true);
691 drm_modeset_drop_locks(&ctx
);
692 drm_modeset_acquire_fini(&ctx
);
694 if (list_empty(&connector
->modes
))
697 drm_mode_sort(&connector
->modes
);
699 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] probed modes:\n",
700 connector
->base
.id
, connector
->name
);
702 list_for_each_entry(mode
, &connector
->modes
, head
) {
703 drm_mode_set_crtcinfo(mode
, CRTC_INTERLACE_HALVE_V
);
704 drm_dbg_kms(dev
, "Probed mode: " DRM_MODE_FMT
"\n",
710 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes
);
713 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
714 * @dev: drm_device whose connector state changed
716 * This function fires off the uevent for userspace and also calls the
717 * client hotplug function, which is most commonly used to inform the fbdev
718 * emulation code and allow it to update the fbcon output configuration.
720 * Drivers should call this from their hotplug handling code when a change is
721 * detected. Note that this function does not do any output detection of its
722 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
725 * This function must be called from process context with no mode
726 * setting locks held.
728 * If only a single connector has changed, consider calling
729 * drm_kms_helper_connector_hotplug_event() instead.
731 void drm_kms_helper_hotplug_event(struct drm_device
*dev
)
733 drm_sysfs_hotplug_event(dev
);
734 drm_client_dev_hotplug(dev
);
736 EXPORT_SYMBOL(drm_kms_helper_hotplug_event
);
739 * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
740 * @connector: drm_connector which has changed
742 * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
743 * fine-grained uevent for a single connector.
745 void drm_kms_helper_connector_hotplug_event(struct drm_connector
*connector
)
747 struct drm_device
*dev
= connector
->dev
;
749 drm_sysfs_connector_hotplug_event(connector
);
750 drm_client_dev_hotplug(dev
);
752 EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event
);
754 static void output_poll_execute(struct work_struct
*work
)
756 struct delayed_work
*delayed_work
= to_delayed_work(work
);
757 struct drm_device
*dev
= container_of(delayed_work
, struct drm_device
, mode_config
.output_poll_work
);
758 struct drm_connector
*connector
;
759 struct drm_connector_list_iter conn_iter
;
760 enum drm_connector_status old_status
;
761 bool repoll
= false, changed
;
762 u64 old_epoch_counter
;
764 if (!dev
->mode_config
.poll_enabled
)
767 /* Pick up any changes detected by the probe functions. */
768 changed
= dev
->mode_config
.delayed_event
;
769 dev
->mode_config
.delayed_event
= false;
771 if (!drm_kms_helper_poll
) {
772 if (dev
->mode_config
.poll_running
) {
773 drm_kms_helper_disable_hpd(dev
);
774 dev
->mode_config
.poll_running
= false;
779 if (!mutex_trylock(&dev
->mode_config
.mutex
)) {
784 drm_connector_list_iter_begin(dev
, &conn_iter
);
785 drm_for_each_connector_iter(connector
, &conn_iter
) {
786 /* Ignore forced connectors. */
787 if (connector
->force
)
790 /* Ignore HPD capable connectors and connectors where we don't
791 * want any hotplug detection at all for polling. */
792 if (!connector
->polled
|| connector
->polled
== DRM_CONNECTOR_POLL_HPD
)
795 old_status
= connector
->status
;
796 /* if we are connected and don't want to poll for disconnect
798 if (old_status
== connector_status_connected
&&
799 !(connector
->polled
& DRM_CONNECTOR_POLL_DISCONNECT
))
804 old_epoch_counter
= connector
->epoch_counter
;
805 connector
->status
= drm_helper_probe_detect(connector
, NULL
, false);
806 if (old_epoch_counter
!= connector
->epoch_counter
) {
807 const char *old
, *new;
810 * The poll work sets force=false when calling detect so
811 * that drivers can avoid to do disruptive tests (e.g.
812 * when load detect cycles could cause flickering on
813 * other, running displays). This bears the risk that we
814 * flip-flop between unknown here in the poll work and
815 * the real state when userspace forces a full detect
816 * call after receiving a hotplug event due to this
819 * Hence clamp an unknown detect status to the old
822 if (connector
->status
== connector_status_unknown
) {
823 connector
->status
= old_status
;
827 old
= drm_get_connector_status_name(old_status
);
828 new = drm_get_connector_status_name(connector
->status
);
830 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
831 connector
->base
.id
, connector
->name
,
833 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
834 connector
->base
.id
, connector
->name
,
835 old_epoch_counter
, connector
->epoch_counter
);
840 drm_connector_list_iter_end(&conn_iter
);
842 mutex_unlock(&dev
->mode_config
.mutex
);
846 drm_kms_helper_hotplug_event(dev
);
849 schedule_delayed_work(delayed_work
, DRM_OUTPUT_POLL_PERIOD
);
853 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
855 * Determine if %current task is an output poll worker. This can be used
856 * to select distinct code paths for output polling versus other contexts.
858 * One use case is to avoid a deadlock between the output poll worker and
859 * the autosuspend worker wherein the latter waits for polling to finish
860 * upon calling drm_kms_helper_poll_disable(), while the former waits for
861 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
862 * connector ->detect hook.
864 bool drm_kms_helper_is_poll_worker(void)
866 struct work_struct
*work
= current_work();
868 return work
&& work
->func
== output_poll_execute
;
870 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker
);
873 * drm_kms_helper_poll_disable - disable output polling
876 * This function disables the output polling work.
878 * Drivers can call this helper from their device suspend implementation. It is
879 * not an error to call this even when output polling isn't enabled or already
880 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
882 * If however, the polling was never initialized, this call will trigger a
883 * warning and return.
885 * Note that calls to enable and disable polling must be strictly ordered, which
886 * is automatically the case when they're only call from suspend/resume
889 void drm_kms_helper_poll_disable(struct drm_device
*dev
)
891 if (drm_WARN_ON(dev
, !dev
->mode_config
.poll_enabled
))
894 if (dev
->mode_config
.poll_running
)
895 drm_kms_helper_disable_hpd(dev
);
897 cancel_delayed_work_sync(&dev
->mode_config
.output_poll_work
);
899 dev
->mode_config
.poll_running
= false;
901 EXPORT_SYMBOL(drm_kms_helper_poll_disable
);
904 * drm_kms_helper_poll_init - initialize and enable output polling
907 * This function initializes and then also enables output polling support for
908 * @dev. Drivers which do not have reliable hotplug support in hardware can use
909 * this helper infrastructure to regularly poll such connectors for changes in
910 * their connection state.
912 * Drivers can control which connectors are polled by setting the
913 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
914 * connectors where probing live outputs can result in visual distortion drivers
915 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
916 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
917 * completely ignored by the polling logic.
919 * Note that a connector can be both polled and probed from the hotplug handler,
920 * in case the hotplug interrupt is known to be unreliable.
922 void drm_kms_helper_poll_init(struct drm_device
*dev
)
924 INIT_DELAYED_WORK(&dev
->mode_config
.output_poll_work
, output_poll_execute
);
925 dev
->mode_config
.poll_enabled
= true;
927 drm_kms_helper_poll_enable(dev
);
929 EXPORT_SYMBOL(drm_kms_helper_poll_init
);
932 * drm_kms_helper_poll_fini - disable output polling and clean it up
935 void drm_kms_helper_poll_fini(struct drm_device
*dev
)
937 if (!dev
->mode_config
.poll_enabled
)
940 drm_kms_helper_poll_disable(dev
);
942 dev
->mode_config
.poll_enabled
= false;
944 EXPORT_SYMBOL(drm_kms_helper_poll_fini
);
946 static void drm_kms_helper_poll_init_release(struct drm_device
*dev
, void *res
)
948 drm_kms_helper_poll_fini(dev
);
952 * drmm_kms_helper_poll_init - initialize and enable output polling
955 * This function initializes and then also enables output polling support for
956 * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be
957 * cleaned up when the DRM device goes away.
959 * See drm_kms_helper_poll_init() for more information.
962 * 0 on success, or a negative errno code otherwise.
964 int drmm_kms_helper_poll_init(struct drm_device
*dev
)
966 drm_kms_helper_poll_init(dev
);
968 return drmm_add_action_or_reset(dev
, drm_kms_helper_poll_init_release
, dev
);
970 EXPORT_SYMBOL(drmm_kms_helper_poll_init
);
972 static bool check_connector_changed(struct drm_connector
*connector
)
974 struct drm_device
*dev
= connector
->dev
;
975 enum drm_connector_status old_status
;
976 u64 old_epoch_counter
;
978 /* Only handle HPD capable connectors. */
979 drm_WARN_ON(dev
, !(connector
->polled
& DRM_CONNECTOR_POLL_HPD
));
981 drm_WARN_ON(dev
, !mutex_is_locked(&dev
->mode_config
.mutex
));
983 old_status
= connector
->status
;
984 old_epoch_counter
= connector
->epoch_counter
;
985 connector
->status
= drm_helper_probe_detect(connector
, NULL
, false);
987 if (old_epoch_counter
== connector
->epoch_counter
) {
988 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
991 connector
->epoch_counter
);
996 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
999 drm_get_connector_status_name(old_status
),
1000 drm_get_connector_status_name(connector
->status
));
1002 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
1006 connector
->epoch_counter
);
1012 * drm_connector_helper_hpd_irq_event - hotplug processing
1013 * @connector: drm_connector
1015 * Drivers can use this helper function to run a detect cycle on a connector
1016 * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
1018 * This helper function is useful for drivers which can track hotplug
1019 * interrupts for a single connector. Drivers that want to send a
1020 * hotplug event for all connectors or can't track hotplug interrupts
1021 * per connector need to use drm_helper_hpd_irq_event().
1023 * This function must be called from process context with no mode
1024 * setting locks held.
1026 * Note that a connector can be both polled and probed from the hotplug
1027 * handler, in case the hotplug interrupt is known to be unreliable.
1030 * A boolean indicating whether the connector status changed or not
1032 bool drm_connector_helper_hpd_irq_event(struct drm_connector
*connector
)
1034 struct drm_device
*dev
= connector
->dev
;
1037 mutex_lock(&dev
->mode_config
.mutex
);
1038 changed
= check_connector_changed(connector
);
1039 mutex_unlock(&dev
->mode_config
.mutex
);
1042 drm_kms_helper_connector_hotplug_event(connector
);
1043 drm_dbg_kms(dev
, "[CONNECTOR:%d:%s] Sent hotplug event\n",
1050 EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event
);
1053 * drm_helper_hpd_irq_event - hotplug processing
1056 * Drivers can use this helper function to run a detect cycle on all connectors
1057 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1058 * other connectors are ignored, which is useful to avoid reprobing fixed
1061 * This helper function is useful for drivers which can't or don't track hotplug
1062 * interrupts for each connector.
1064 * Drivers which support hotplug interrupts for each connector individually and
1065 * which have a more fine-grained detect logic can use
1066 * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
1067 * code and directly call drm_kms_helper_hotplug_event() in case the connector
1070 * This function must be called from process context with no mode
1071 * setting locks held.
1073 * Note that a connector can be both polled and probed from the hotplug handler,
1074 * in case the hotplug interrupt is known to be unreliable.
1077 * A boolean indicating whether the connector status changed or not
1079 bool drm_helper_hpd_irq_event(struct drm_device
*dev
)
1081 struct drm_connector
*connector
, *first_changed_connector
= NULL
;
1082 struct drm_connector_list_iter conn_iter
;
1085 if (!dev
->mode_config
.poll_enabled
)
1088 mutex_lock(&dev
->mode_config
.mutex
);
1089 drm_connector_list_iter_begin(dev
, &conn_iter
);
1090 drm_for_each_connector_iter(connector
, &conn_iter
) {
1091 /* Only handle HPD capable connectors. */
1092 if (!(connector
->polled
& DRM_CONNECTOR_POLL_HPD
))
1095 if (check_connector_changed(connector
)) {
1096 if (!first_changed_connector
) {
1097 drm_connector_get(connector
);
1098 first_changed_connector
= connector
;
1104 drm_connector_list_iter_end(&conn_iter
);
1105 mutex_unlock(&dev
->mode_config
.mutex
);
1108 drm_kms_helper_connector_hotplug_event(first_changed_connector
);
1109 else if (changed
> 0)
1110 drm_kms_helper_hotplug_event(dev
);
1112 if (first_changed_connector
)
1113 drm_connector_put(first_changed_connector
);
1117 EXPORT_SYMBOL(drm_helper_hpd_irq_event
);
1120 * drm_crtc_helper_mode_valid_fixed - Validates a display mode
1122 * @mode: the mode to validate
1123 * @fixed_mode: the display hardware's mode
1126 * MODE_OK on success, or another mode-status code otherwise.
1128 enum drm_mode_status
drm_crtc_helper_mode_valid_fixed(struct drm_crtc
*crtc
,
1129 const struct drm_display_mode
*mode
,
1130 const struct drm_display_mode
*fixed_mode
)
1132 if (mode
->hdisplay
!= fixed_mode
->hdisplay
&& mode
->vdisplay
!= fixed_mode
->vdisplay
)
1133 return MODE_ONE_SIZE
;
1134 else if (mode
->hdisplay
!= fixed_mode
->hdisplay
)
1135 return MODE_ONE_WIDTH
;
1136 else if (mode
->vdisplay
!= fixed_mode
->vdisplay
)
1137 return MODE_ONE_HEIGHT
;
1141 EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed
);
1144 * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
1145 * @connector: the connector
1146 * @fixed_mode: the display hardware's mode
1148 * This function duplicates a display modes for a connector. Drivers for hardware
1149 * that only supports a single fixed mode can use this function in their connector's
1153 * The number of created modes.
1155 int drm_connector_helper_get_modes_fixed(struct drm_connector
*connector
,
1156 const struct drm_display_mode
*fixed_mode
)
1158 struct drm_device
*dev
= connector
->dev
;
1159 struct drm_display_mode
*mode
;
1161 mode
= drm_mode_duplicate(dev
, fixed_mode
);
1163 drm_err(dev
, "Failed to duplicate mode " DRM_MODE_FMT
"\n",
1164 DRM_MODE_ARG(fixed_mode
));
1168 if (mode
->name
[0] == '\0')
1169 drm_mode_set_name(mode
);
1171 mode
->type
|= DRM_MODE_TYPE_PREFERRED
;
1172 drm_mode_probed_add(connector
, mode
);
1175 connector
->display_info
.width_mm
= mode
->width_mm
;
1176 if (mode
->height_mm
)
1177 connector
->display_info
.height_mm
= mode
->height_mm
;
1181 EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed
);
1184 * drm_connector_helper_get_modes - Read EDID and update connector.
1185 * @connector: The connector
1187 * Read the EDID using drm_edid_read() (which requires that connector->ddc is
1188 * set), and update the connector using the EDID.
1190 * This can be used as the "default" connector helper .get_modes() hook if the
1191 * driver does not need any special processing. This is sets the example what
1192 * custom .get_modes() hooks should do regarding EDID read and connector update.
1194 * Returns: Number of modes.
1196 int drm_connector_helper_get_modes(struct drm_connector
*connector
)
1198 const struct drm_edid
*drm_edid
;
1201 drm_edid
= drm_edid_read(connector
);
1204 * Unconditionally update the connector. If the EDID was read
1205 * successfully, fill in the connector information derived from the
1206 * EDID. Otherwise, if the EDID is NULL, clear the connector
1209 drm_edid_connector_update(connector
, drm_edid
);
1211 count
= drm_edid_connector_add_modes(connector
);
1213 drm_edid_free(drm_edid
);
1217 EXPORT_SYMBOL(drm_connector_helper_get_modes
);
1220 * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector
1221 * @connector: The connector
1223 * Fills the available modes for a TV connector based on the supported
1224 * TV modes, and the default mode expressed by the kernel command line.
1226 * This can be used as the default TV connector helper .get_modes() hook
1227 * if the driver does not need any special processing.
1230 * The number of modes added to the connector.
1232 int drm_connector_helper_tv_get_modes(struct drm_connector
*connector
)
1234 struct drm_device
*dev
= connector
->dev
;
1235 struct drm_property
*tv_mode_property
=
1236 dev
->mode_config
.tv_mode_property
;
1237 struct drm_cmdline_mode
*cmdline
= &connector
->cmdline_mode
;
1238 unsigned int ntsc_modes
= BIT(DRM_MODE_TV_MODE_NTSC
) |
1239 BIT(DRM_MODE_TV_MODE_NTSC_443
) |
1240 BIT(DRM_MODE_TV_MODE_NTSC_J
) |
1241 BIT(DRM_MODE_TV_MODE_PAL_M
);
1242 unsigned int pal_modes
= BIT(DRM_MODE_TV_MODE_PAL
) |
1243 BIT(DRM_MODE_TV_MODE_PAL_N
) |
1244 BIT(DRM_MODE_TV_MODE_SECAM
);
1245 unsigned int tv_modes
[2] = { UINT_MAX
, UINT_MAX
};
1246 unsigned int i
, supported_tv_modes
= 0;
1248 if (!tv_mode_property
)
1251 for (i
= 0; i
< tv_mode_property
->num_values
; i
++)
1252 supported_tv_modes
|= BIT(tv_mode_property
->values
[i
]);
1254 if (((supported_tv_modes
& ntsc_modes
) &&
1255 (supported_tv_modes
& pal_modes
)) ||
1256 (supported_tv_modes
& BIT(DRM_MODE_TV_MODE_MONOCHROME
))) {
1257 uint64_t default_mode
;
1259 if (drm_object_property_get_default_value(&connector
->base
,
1264 if (cmdline
->tv_mode_specified
)
1265 default_mode
= cmdline
->tv_mode
;
1267 if (BIT(default_mode
) & ntsc_modes
) {
1268 tv_modes
[0] = DRM_MODE_TV_MODE_NTSC
;
1269 tv_modes
[1] = DRM_MODE_TV_MODE_PAL
;
1271 tv_modes
[0] = DRM_MODE_TV_MODE_PAL
;
1272 tv_modes
[1] = DRM_MODE_TV_MODE_NTSC
;
1274 } else if (supported_tv_modes
& ntsc_modes
) {
1275 tv_modes
[0] = DRM_MODE_TV_MODE_NTSC
;
1276 } else if (supported_tv_modes
& pal_modes
) {
1277 tv_modes
[0] = DRM_MODE_TV_MODE_PAL
;
1282 for (i
= 0; i
< ARRAY_SIZE(tv_modes
); i
++) {
1283 struct drm_display_mode
*mode
;
1285 if (tv_modes
[i
] == DRM_MODE_TV_MODE_NTSC
)
1286 mode
= drm_mode_analog_ntsc_480i(dev
);
1287 else if (tv_modes
[i
] == DRM_MODE_TV_MODE_PAL
)
1288 mode
= drm_mode_analog_pal_576i(dev
);
1294 mode
->type
|= DRM_MODE_TYPE_PREFERRED
;
1295 drm_mode_probed_add(connector
, mode
);
1300 EXPORT_SYMBOL(drm_connector_helper_tv_get_modes
);
1303 * drm_connector_helper_detect_from_ddc - Read EDID and detect connector status.
1304 * @connector: The connector
1305 * @ctx: Acquire context
1306 * @force: Perform screen-destructive operations, if necessary
1308 * Detects the connector status by reading the EDID using drm_probe_ddc(),
1309 * which requires connector->ddc to be set. Returns connector_status_connected
1310 * on success or connector_status_disconnected on failure.
1313 * The connector status as defined by enum drm_connector_status.
1315 int drm_connector_helper_detect_from_ddc(struct drm_connector
*connector
,
1316 struct drm_modeset_acquire_ctx
*ctx
,
1319 struct i2c_adapter
*ddc
= connector
->ddc
;
1322 return connector_status_unknown
;
1324 if (drm_probe_ddc(ddc
))
1325 return connector_status_connected
;
1327 return connector_status_disconnected
;
1329 EXPORT_SYMBOL(drm_connector_helper_detect_from_ddc
);