2 * Copyright © 2006 Keith Packard
3 * Copyright © 2007-2008 Dave Airlie
4 * Copyright © 2007-2008 Intel Corporation
5 * Jesse Barnes <jesse.barnes@intel.com>
6 * Copyright © 2011-2013 Intel Corporation
7 * Copyright © 2015 Intel Corporation
8 * Daniel Vetter <daniel.vetter@ffwll.ch>
10 * Permission is hereby granted, free of charge, to any person obtaining a
11 * copy of this software and associated documentation files (the "Software"),
12 * to deal in the Software without restriction, including without limitation
13 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
14 * and/or sell copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following conditions:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
29 #ifndef __DRM_MODESET_HELPER_VTABLES_H__
30 #define __DRM_MODESET_HELPER_VTABLES_H__
32 #include <drm/drm_crtc.h>
33 #include <drm/drm_encoder.h>
38 * The DRM mode setting helper functions are common code for drivers to use if
39 * they wish. Drivers are not forced to use this code in their
40 * implementations but it would be useful if the code they do use at least
41 * provides a consistent interface and operation to userspace. Therefore it is
42 * highly recommended to use the provided helpers as much as possible.
44 * Because there is only one pointer per modeset object to hold a vfunc table
45 * for helper libraries they are by necessity shared among the different
48 * To make this clear all the helper vtables are pulled together in this location here.
52 struct drm_writeback_connector;
53 struct drm_writeback_job;
56 * struct drm_crtc_helper_funcs - helper operations for CRTCs
58 * These hooks are used by the legacy CRTC helpers, the transitional plane
59 * helpers and the new atomic modesetting helpers.
61 struct drm_crtc_helper_funcs {
65 * Callback to control power levels on the CRTC. If the mode passed in
66 * is unsupported, the provider must use the next lowest power level.
67 * This is used by the legacy CRTC helpers to implement DPMS
68 * functionality in drm_helper_connector_dpms().
70 * This callback is also used to disable a CRTC by calling it with
71 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
73 * This callback is used by the legacy CRTC helpers. Atomic helpers
74 * also support using this hook for enabling and disabling a CRTC to
75 * facilitate transitions to atomic, but it is deprecated. Instead
76 * @atomic_enable and @atomic_disable should be used.
78 void (*dpms)(struct drm_crtc *crtc, int mode);
83 * This callback should prepare the CRTC for a subsequent modeset, which
84 * in practice means the driver should disable the CRTC if it is
85 * running. Most drivers ended up implementing this by calling their
86 * @dpms hook with DRM_MODE_DPMS_OFF.
88 * This callback is used by the legacy CRTC helpers. Atomic helpers
89 * also support using this hook for disabling a CRTC to facilitate
90 * transitions to atomic, but it is deprecated. Instead @atomic_disable
93 void (*prepare)(struct drm_crtc *crtc);
98 * This callback should commit the new mode on the CRTC after a modeset,
99 * which in practice means the driver should enable the CRTC. Most
100 * drivers ended up implementing this by calling their @dpms hook with
103 * This callback is used by the legacy CRTC helpers. Atomic helpers
104 * also support using this hook for enabling a CRTC to facilitate
105 * transitions to atomic, but it is deprecated. Instead @atomic_enable
108 void (*commit)(struct drm_crtc *crtc);
113 * This callback is used to check if a specific mode is valid in this
114 * crtc. This should be implemented if the crtc has some sort of
115 * restriction in the modes it can display. For example, a given crtc
116 * may be responsible to set a clock value. If the clock can not
117 * produce all the values for the available modes then this callback
118 * can be used to restrict the number of modes to only the ones that
121 * This hook is used by the probe helpers to filter the mode list in
122 * drm_helper_probe_single_connector_modes(), and it is used by the
123 * atomic helpers to validate modes supplied by userspace in
124 * drm_atomic_helper_check_modeset().
126 * This function is optional.
130 * Since this function is both called from the check phase of an atomic
131 * commit, and the mode validation in the probe paths it is not allowed
132 * to look at anything else but the passed-in mode, and validate it
133 * against configuration-invariant hardward constraints. Any further
134 * limits which depend upon the configuration can only be checked in
135 * @mode_fixup or @atomic_check.
139 * drm_mode_status Enum
141 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
142 const struct drm_display_mode *mode);
147 * This callback is used to validate a mode. The parameter mode is the
148 * display mode that userspace requested, adjusted_mode is the mode the
149 * encoders need to be fed with. Note that this is the inverse semantics
150 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
151 * vfunc. If the CRTC cannot support the requested conversion from mode
152 * to adjusted_mode it should reject the modeset. See also
153 * &drm_crtc_state.adjusted_mode for more details.
155 * This function is used by both legacy CRTC helpers and atomic helpers.
156 * With atomic helpers it is optional.
160 * This function is called in the check phase of atomic modesets, which
161 * can be aborted for any reason (including on userspace's request to
162 * just check whether a configuration would be possible). Atomic drivers
163 * MUST NOT touch any persistent state (hardware or software) or data
164 * structures except the passed in adjusted_mode parameter.
166 * This is in contrast to the legacy CRTC helpers where this was
169 * Atomic drivers which need to inspect and adjust more state should
170 * instead use the @atomic_check callback, but note that they're not
171 * perfectly equivalent: @mode_valid is called from
172 * drm_atomic_helper_check_modeset(), but @atomic_check is called from
173 * drm_atomic_helper_check_planes(), because originally it was meant for
174 * plane update checks only.
176 * Also beware that userspace can request its own custom modes, neither
177 * core nor helpers filter modes to the list of probe modes reported by
178 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
179 * that modes are filtered consistently put any CRTC constraints and
180 * limits checks into @mode_valid.
184 * True if an acceptable configuration is possible, false if the modeset
185 * operation should be rejected.
187 bool (*mode_fixup)(struct drm_crtc *crtc,
188 const struct drm_display_mode *mode,
189 struct drm_display_mode *adjusted_mode);
194 * This callback is used by the legacy CRTC helpers to set a new mode,
195 * position and framebuffer. Since it ties the primary plane to every
196 * mode change it is incompatible with universal plane support. And
197 * since it can't update other planes it's incompatible with atomic
200 * This callback is only used by CRTC helpers and deprecated.
204 * 0 on success or a negative error code on failure.
206 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
207 struct drm_display_mode *adjusted_mode, int x, int y,
208 struct drm_framebuffer *old_fb);
213 * This callback is used to update the display mode of a CRTC without
214 * changing anything of the primary plane configuration. This fits the
215 * requirement of atomic and hence is used by the atomic helpers. It is
216 * also used by the transitional plane helpers to implement a
217 * @mode_set hook in drm_helper_crtc_mode_set().
219 * Note that the display pipe is completely off when this function is
220 * called. Atomic drivers which need hardware to be running before they
221 * program the new display mode (e.g. because they implement runtime PM)
222 * should not use this hook. This is because the helper library calls
223 * this hook only once per mode change and not every time the display
224 * pipeline is suspended using either DPMS or the new "ACTIVE" property.
225 * Which means register values set in this callback might get reset when
226 * the CRTC is suspended, but not restored. Such drivers should instead
227 * move all their CRTC setup into the @atomic_enable callback.
229 * This callback is optional.
231 void (*mode_set_nofb)(struct drm_crtc *crtc);
236 * This callback is used by the legacy CRTC helpers to set a new
237 * framebuffer and scanout position. It is optional and used as an
238 * optimized fast-path instead of a full mode set operation with all the
239 * resulting flickering. If it is not present
240 * drm_crtc_helper_set_config() will fall back to a full modeset, using
241 * the @mode_set callback. Since it can't update other planes it's
242 * incompatible with atomic modeset support.
244 * This callback is only used by the CRTC helpers and deprecated.
248 * 0 on success or a negative error code on failure.
250 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
251 struct drm_framebuffer *old_fb);
254 * @mode_set_base_atomic:
256 * This callback is used by the fbdev helpers to set a new framebuffer
257 * and scanout without sleeping, i.e. from an atomic calling context. It
258 * is only used to implement kgdb support.
260 * This callback is optional and only needed for kgdb support in the fbdev
265 * 0 on success or a negative error code on failure.
267 int (*mode_set_base_atomic)(struct drm_crtc *crtc,
268 struct drm_framebuffer *fb, int x, int y,
269 enum mode_set_atomic);
274 * This callback should be used to disable the CRTC. With the atomic
275 * drivers it is called after all encoders connected to this CRTC have
276 * been shut off already using their own
277 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
278 * simple drivers can just add their own hooks and call it from this
279 * CRTC callback here by looping over all encoders connected to it using
280 * for_each_encoder_on_crtc().
282 * This hook is used both by legacy CRTC helpers and atomic helpers.
283 * Atomic drivers don't need to implement it if there's no need to
284 * disable anything at the CRTC level. To ensure that runtime PM
285 * handling (using either DPMS or the new "ACTIVE" property) works
286 * @disable must be the inverse of @atomic_enable for atomic drivers.
287 * Atomic drivers should consider to use @atomic_disable instead of
292 * With legacy CRTC helpers there's a big semantic difference between
293 * @disable and other hooks (like @prepare or @dpms) used to shut down a
294 * CRTC: @disable is only called when also logically disabling the
295 * display pipeline and needs to release any resources acquired in
296 * @mode_set (like shared PLLs, or again release pinned framebuffers).
298 * Therefore @disable must be the inverse of @mode_set plus @commit for
299 * drivers still using legacy CRTC helpers, which is different from the
300 * rules under atomic.
302 void (*disable)(struct drm_crtc *crtc);
307 * Drivers should check plane-update related CRTC constraints in this
308 * hook. They can also check mode related limitations but need to be
309 * aware of the calling order, since this hook is used by
310 * drm_atomic_helper_check_planes() whereas the preparations needed to
311 * check output routing and the display mode is done in
312 * drm_atomic_helper_check_modeset(). Therefore drivers that want to
313 * check output routing and display mode constraints in this callback
314 * must ensure that drm_atomic_helper_check_modeset() has been called
315 * beforehand. This is calling order used by the default helper
316 * implementation in drm_atomic_helper_check().
318 * When using drm_atomic_helper_check_planes() this hook is called
319 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which
320 * allows drivers to assign shared resources requested by planes in this
321 * callback here. For more complicated dependencies the driver can call
322 * the provided check helpers multiple times until the computed state
323 * has a final configuration and everything has been checked.
325 * This function is also allowed to inspect any other object's state and
326 * can add more state objects to the atomic commit if needed. Care must
327 * be taken though to ensure that state check and compute functions for
328 * these added states are all called, and derived state in other objects
329 * all updated. Again the recommendation is to just call check helpers
330 * until a maximal configuration is reached.
332 * This callback is used by the atomic modeset helpers and by the
333 * transitional plane helpers, but it is optional.
337 * This function is called in the check phase of an atomic update. The
338 * driver is not allowed to change anything outside of the free-standing
339 * state objects passed-in or assembled in the overall &drm_atomic_state
340 * update tracking structure.
342 * Also beware that userspace can request its own custom modes, neither
343 * core nor helpers filter modes to the list of probe modes reported by
344 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
345 * that modes are filtered consistently put any CRTC constraints and
346 * limits checks into @mode_valid.
350 * 0 on success, -EINVAL if the state or the transition can't be
351 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
352 * attempt to obtain another state object ran into a &drm_modeset_lock
355 int (*atomic_check)(struct drm_crtc *crtc,
356 struct drm_crtc_state *state);
361 * Drivers should prepare for an atomic update of multiple planes on
362 * a CRTC in this hook. Depending upon hardware this might be vblank
363 * evasion, blocking updates by setting bits or doing preparatory work
364 * for e.g. manual update display.
366 * This hook is called before any plane commit functions are called.
368 * Note that the power state of the display pipe when this function is
369 * called depends upon the exact helpers and calling sequence the driver
370 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
371 * the tradeoffs and variants of plane commit helpers.
373 * This callback is used by the atomic modeset helpers and by the
374 * transitional plane helpers, but it is optional.
376 void (*atomic_begin)(struct drm_crtc *crtc,
377 struct drm_crtc_state *old_crtc_state);
381 * Drivers should finalize an atomic update of multiple planes on
382 * a CRTC in this hook. Depending upon hardware this might include
383 * checking that vblank evasion was successful, unblocking updates by
384 * setting bits or setting the GO bit to flush out all updates.
386 * Simple hardware or hardware with special requirements can commit and
387 * flush out all updates for all planes from this hook and forgo all the
388 * other commit hooks for plane updates.
390 * This hook is called after any plane commit functions are called.
392 * Note that the power state of the display pipe when this function is
393 * called depends upon the exact helpers and calling sequence the driver
394 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
395 * the tradeoffs and variants of plane commit helpers.
397 * This callback is used by the atomic modeset helpers and by the
398 * transitional plane helpers, but it is optional.
400 void (*atomic_flush)(struct drm_crtc *crtc,
401 struct drm_crtc_state *old_crtc_state);
406 * This callback should be used to enable the CRTC. With the atomic
407 * drivers it is called before all encoders connected to this CRTC are
408 * enabled through the encoder's own &drm_encoder_helper_funcs.enable
409 * hook. If that sequence is too simple drivers can just add their own
410 * hooks and call it from this CRTC callback here by looping over all
411 * encoders connected to it using for_each_encoder_on_crtc().
413 * This hook is used only by atomic helpers, for symmetry with
414 * @atomic_disable. Atomic drivers don't need to implement it if there's
415 * no need to enable anything at the CRTC level. To ensure that runtime
416 * PM handling (using either DPMS or the new "ACTIVE" property) works
417 * @atomic_enable must be the inverse of @atomic_disable for atomic
420 * Drivers can use the @old_crtc_state input parameter if the operations
421 * needed to enable the CRTC don't depend solely on the new state but
422 * also on the transition between the old state and the new state.
424 * This function is optional.
426 void (*atomic_enable)(struct drm_crtc *crtc,
427 struct drm_crtc_state *old_crtc_state);
432 * This callback should be used to disable the CRTC. With the atomic
433 * drivers it is called after all encoders connected to this CRTC have
434 * been shut off already using their own
435 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
436 * simple drivers can just add their own hooks and call it from this
437 * CRTC callback here by looping over all encoders connected to it using
438 * for_each_encoder_on_crtc().
440 * This hook is used only by atomic helpers. Atomic drivers don't
441 * need to implement it if there's no need to disable anything at the
444 * Comparing to @disable, this one provides the additional input
445 * parameter @old_crtc_state which could be used to access the old
446 * state. Atomic drivers should consider to use this one instead
449 * This function is optional.
451 void (*atomic_disable)(struct drm_crtc *crtc,
452 struct drm_crtc_state *old_crtc_state);
455 * @get_scanout_position:
457 * Called by vblank timestamping code.
459 * Returns the current display scanout position from a CRTC and an
460 * optional accurate ktime_get() timestamp of when the position was
461 * measured. Note that this is a helper callback which is only used
462 * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp()
463 * for the @drm_crtc_funcs.get_vblank_timestamp callback.
470 * True when called from drm_crtc_handle_vblank(). Some drivers
471 * need to apply some workarounds for gpu-specific vblank irq
472 * quirks if the flag is set.
474 * Target location for current vertical scanout position.
476 * Target location for current horizontal scanout position.
478 * Target location for timestamp taken immediately before
479 * scanout position query. Can be NULL to skip timestamp.
481 * Target location for timestamp taken immediately after
482 * scanout position query. Can be NULL to skip timestamp.
484 * Current display timings.
486 * Returns vpos as a positive number while in active scanout area.
487 * Returns vpos as a negative number inside vblank, counting the number
488 * of scanlines to go until end of vblank, e.g., -1 means "one scanline
489 * until start of active scanout / end of vblank."
493 * True on success, false if a reliable scanout position counter could
496 bool (*get_scanout_position)(struct drm_crtc *crtc,
497 bool in_vblank_irq, int *vpos, int *hpos,
498 ktime_t *stime, ktime_t *etime,
499 const struct drm_display_mode *mode);
503 * drm_crtc_helper_add - sets the helper vtable for a crtc
505 * @funcs: helper vtable to set for @crtc
507 static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
508 const struct drm_crtc_helper_funcs *funcs)
510 crtc->helper_private = funcs;
514 * struct drm_encoder_helper_funcs - helper operations for encoders
516 * These hooks are used by the legacy CRTC helpers, the transitional plane
517 * helpers and the new atomic modesetting helpers.
519 struct drm_encoder_helper_funcs {
523 * Callback to control power levels on the encoder. If the mode passed in
524 * is unsupported, the provider must use the next lowest power level.
525 * This is used by the legacy encoder helpers to implement DPMS
526 * functionality in drm_helper_connector_dpms().
528 * This callback is also used to disable an encoder by calling it with
529 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
531 * This callback is used by the legacy CRTC helpers. Atomic helpers
532 * also support using this hook for enabling and disabling an encoder to
533 * facilitate transitions to atomic, but it is deprecated. Instead
534 * @enable and @disable should be used.
536 void (*dpms)(struct drm_encoder *encoder, int mode);
541 * This callback is used to check if a specific mode is valid in this
542 * encoder. This should be implemented if the encoder has some sort
543 * of restriction in the modes it can display. For example, a given
544 * encoder may be responsible to set a clock value. If the clock can
545 * not produce all the values for the available modes then this callback
546 * can be used to restrict the number of modes to only the ones that
549 * This hook is used by the probe helpers to filter the mode list in
550 * drm_helper_probe_single_connector_modes(), and it is used by the
551 * atomic helpers to validate modes supplied by userspace in
552 * drm_atomic_helper_check_modeset().
554 * This function is optional.
558 * Since this function is both called from the check phase of an atomic
559 * commit, and the mode validation in the probe paths it is not allowed
560 * to look at anything else but the passed-in mode, and validate it
561 * against configuration-invariant hardward constraints. Any further
562 * limits which depend upon the configuration can only be checked in
563 * @mode_fixup or @atomic_check.
567 * drm_mode_status Enum
569 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
570 const struct drm_display_mode *mode);
575 * This callback is used to validate and adjust a mode. The parameter
576 * mode is the display mode that should be fed to the next element in
577 * the display chain, either the final &drm_connector or a &drm_bridge.
578 * The parameter adjusted_mode is the input mode the encoder requires. It
579 * can be modified by this callback and does not need to match mode. See
580 * also &drm_crtc_state.adjusted_mode for more details.
582 * This function is used by both legacy CRTC helpers and atomic helpers.
583 * This hook is optional.
587 * This function is called in the check phase of atomic modesets, which
588 * can be aborted for any reason (including on userspace's request to
589 * just check whether a configuration would be possible). Atomic drivers
590 * MUST NOT touch any persistent state (hardware or software) or data
591 * structures except the passed in adjusted_mode parameter.
593 * This is in contrast to the legacy CRTC helpers where this was
596 * Atomic drivers which need to inspect and adjust more state should
597 * instead use the @atomic_check callback. If @atomic_check is used,
598 * this hook isn't called since @atomic_check allows a strict superset
599 * of the functionality of @mode_fixup.
601 * Also beware that userspace can request its own custom modes, neither
602 * core nor helpers filter modes to the list of probe modes reported by
603 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
604 * that modes are filtered consistently put any encoder constraints and
605 * limits checks into @mode_valid.
609 * True if an acceptable configuration is possible, false if the modeset
610 * operation should be rejected.
612 bool (*mode_fixup)(struct drm_encoder *encoder,
613 const struct drm_display_mode *mode,
614 struct drm_display_mode *adjusted_mode);
619 * This callback should prepare the encoder for a subsequent modeset,
620 * which in practice means the driver should disable the encoder if it
621 * is running. Most drivers ended up implementing this by calling their
622 * @dpms hook with DRM_MODE_DPMS_OFF.
624 * This callback is used by the legacy CRTC helpers. Atomic helpers
625 * also support using this hook for disabling an encoder to facilitate
626 * transitions to atomic, but it is deprecated. Instead @disable should
629 void (*prepare)(struct drm_encoder *encoder);
634 * This callback should commit the new mode on the encoder after a modeset,
635 * which in practice means the driver should enable the encoder. Most
636 * drivers ended up implementing this by calling their @dpms hook with
639 * This callback is used by the legacy CRTC helpers. Atomic helpers
640 * also support using this hook for enabling an encoder to facilitate
641 * transitions to atomic, but it is deprecated. Instead @enable should
644 void (*commit)(struct drm_encoder *encoder);
649 * This callback is used to update the display mode of an encoder.
651 * Note that the display pipe is completely off when this function is
652 * called. Drivers which need hardware to be running before they program
653 * the new display mode (because they implement runtime PM) should not
654 * use this hook, because the helper library calls it only once and not
655 * every time the display pipeline is suspend using either DPMS or the
656 * new "ACTIVE" property. Such drivers should instead move all their
657 * encoder setup into the @enable callback.
659 * This callback is used both by the legacy CRTC helpers and the atomic
660 * modeset helpers. It is optional in the atomic helpers.
664 * If the driver uses the atomic modeset helpers and needs to inspect
665 * the connector state or connector display info during mode setting,
666 * @atomic_mode_set can be used instead.
668 void (*mode_set)(struct drm_encoder *encoder,
669 struct drm_display_mode *mode,
670 struct drm_display_mode *adjusted_mode);
675 * This callback is used to update the display mode of an encoder.
677 * Note that the display pipe is completely off when this function is
678 * called. Drivers which need hardware to be running before they program
679 * the new display mode (because they implement runtime PM) should not
680 * use this hook, because the helper library calls it only once and not
681 * every time the display pipeline is suspended using either DPMS or the
682 * new "ACTIVE" property. Such drivers should instead move all their
683 * encoder setup into the @enable callback.
685 * This callback is used by the atomic modeset helpers in place of the
686 * @mode_set callback, if set by the driver. It is optional and should
687 * be used instead of @mode_set if the driver needs to inspect the
688 * connector state or display info, since there is no direct way to
689 * go from the encoder to the current connector.
691 void (*atomic_mode_set)(struct drm_encoder *encoder,
692 struct drm_crtc_state *crtc_state,
693 struct drm_connector_state *conn_state);
698 * This callback is used by the legacy CRTC helpers to work around
699 * deficiencies in its own book-keeping.
701 * Do not use, use atomic helpers instead, which get the book keeping
706 * Currently only nouveau is using this, and as soon as nouveau is
707 * atomic we can ditch this hook.
709 struct drm_crtc *(*get_crtc)(struct drm_encoder *encoder);
714 * This callback can be used by drivers who want to do detection on the
715 * encoder object instead of in connector functions.
717 * It is not used by any helper and therefore has purely driver-specific
718 * semantics. New drivers shouldn't use this and instead just implement
719 * their own private callbacks.
723 * This should just be converted into a pile of driver vfuncs.
724 * Currently radeon, amdgpu and nouveau are using it.
726 enum drm_connector_status (*detect)(struct drm_encoder *encoder,
727 struct drm_connector *connector);
732 * This callback should be used to disable the encoder. With the atomic
733 * drivers it is called before this encoder's CRTC has been shut off
734 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
735 * sequence is too simple drivers can just add their own driver private
736 * encoder hooks and call them from CRTC's callback by looping over all
737 * encoders connected to it using for_each_encoder_on_crtc().
739 * This callback is a variant of @disable that provides the atomic state
740 * to the driver. If @atomic_disable is implemented, @disable is not
741 * called by the helpers.
743 * This hook is only used by atomic helpers. Atomic drivers don't need
744 * to implement it if there's no need to disable anything at the encoder
745 * level. To ensure that runtime PM handling (using either DPMS or the
746 * new "ACTIVE" property) works @atomic_disable must be the inverse of
749 void (*atomic_disable)(struct drm_encoder *encoder,
750 struct drm_atomic_state *state);
755 * This callback should be used to enable the encoder. It is called
756 * after this encoder's CRTC has been enabled using their own
757 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
758 * too simple drivers can just add their own driver private encoder
759 * hooks and call them from CRTC's callback by looping over all encoders
760 * connected to it using for_each_encoder_on_crtc().
762 * This callback is a variant of @enable that provides the atomic state
763 * to the driver. If @atomic_enable is implemented, @enable is not
764 * called by the helpers.
766 * This hook is only used by atomic helpers, it is the opposite of
767 * @atomic_disable. Atomic drivers don't need to implement it if there's
768 * no need to enable anything at the encoder level. To ensure that
769 * runtime PM handling works @atomic_enable must be the inverse of
772 void (*atomic_enable)(struct drm_encoder *encoder,
773 struct drm_atomic_state *state);
778 * This callback should be used to disable the encoder. With the atomic
779 * drivers it is called before this encoder's CRTC has been shut off
780 * using their own &drm_crtc_helper_funcs.disable hook. If that
781 * sequence is too simple drivers can just add their own driver private
782 * encoder hooks and call them from CRTC's callback by looping over all
783 * encoders connected to it using for_each_encoder_on_crtc().
785 * This hook is used both by legacy CRTC helpers and atomic helpers.
786 * Atomic drivers don't need to implement it if there's no need to
787 * disable anything at the encoder level. To ensure that runtime PM
788 * handling (using either DPMS or the new "ACTIVE" property) works
789 * @disable must be the inverse of @enable for atomic drivers.
791 * For atomic drivers also consider @atomic_disable and save yourself
792 * from having to read the NOTE below!
796 * With legacy CRTC helpers there's a big semantic difference between
797 * @disable and other hooks (like @prepare or @dpms) used to shut down a
798 * encoder: @disable is only called when also logically disabling the
799 * display pipeline and needs to release any resources acquired in
800 * @mode_set (like shared PLLs, or again release pinned framebuffers).
802 * Therefore @disable must be the inverse of @mode_set plus @commit for
803 * drivers still using legacy CRTC helpers, which is different from the
804 * rules under atomic.
806 void (*disable)(struct drm_encoder *encoder);
811 * This callback should be used to enable the encoder. With the atomic
812 * drivers it is called after this encoder's CRTC has been enabled using
813 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
814 * too simple drivers can just add their own driver private encoder
815 * hooks and call them from CRTC's callback by looping over all encoders
816 * connected to it using for_each_encoder_on_crtc().
818 * This hook is only used by atomic helpers, it is the opposite of
819 * @disable. Atomic drivers don't need to implement it if there's no
820 * need to enable anything at the encoder level. To ensure that
821 * runtime PM handling (using either DPMS or the new "ACTIVE" property)
822 * works @enable must be the inverse of @disable for atomic drivers.
824 void (*enable)(struct drm_encoder *encoder);
829 * This callback is used to validate encoder state for atomic drivers.
830 * Since the encoder is the object connecting the CRTC and connector it
831 * gets passed both states, to be able to validate interactions and
832 * update the CRTC to match what the encoder needs for the requested
835 * Since this provides a strict superset of the functionality of
836 * @mode_fixup (the requested and adjusted modes are both available
837 * through the passed in &struct drm_crtc_state) @mode_fixup is not
838 * called when @atomic_check is implemented.
840 * This function is used by the atomic helpers, but it is optional.
844 * This function is called in the check phase of an atomic update. The
845 * driver is not allowed to change anything outside of the free-standing
846 * state objects passed-in or assembled in the overall &drm_atomic_state
847 * update tracking structure.
849 * Also beware that userspace can request its own custom modes, neither
850 * core nor helpers filter modes to the list of probe modes reported by
851 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
852 * that modes are filtered consistently put any encoder constraints and
853 * limits checks into @mode_valid.
857 * 0 on success, -EINVAL if the state or the transition can't be
858 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
859 * attempt to obtain another state object ran into a &drm_modeset_lock
862 int (*atomic_check)(struct drm_encoder *encoder,
863 struct drm_crtc_state *crtc_state,
864 struct drm_connector_state *conn_state);
868 * drm_encoder_helper_add - sets the helper vtable for an encoder
869 * @encoder: DRM encoder
870 * @funcs: helper vtable to set for @encoder
872 static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
873 const struct drm_encoder_helper_funcs *funcs)
875 encoder->helper_private = funcs;
879 * struct drm_connector_helper_funcs - helper operations for connectors
881 * These functions are used by the atomic and legacy modeset helpers and by the
884 struct drm_connector_helper_funcs {
888 * This function should fill in all modes currently valid for the sink
889 * into the &drm_connector.probed_modes list. It should also update the
890 * EDID property by calling drm_connector_update_edid_property().
892 * The usual way to implement this is to cache the EDID retrieved in the
893 * probe callback somewhere in the driver-private connector structure.
894 * In this function drivers then parse the modes in the EDID and add
895 * them by calling drm_add_edid_modes(). But connectors that driver a
896 * fixed panel can also manually add specific modes using
897 * drm_mode_probed_add(). Drivers which manually add modes should also
898 * make sure that the &drm_connector.display_info,
899 * &drm_connector.width_mm and &drm_connector.height_mm fields are
902 * Virtual drivers that just want some standard VESA mode with a given
903 * resolution can call drm_add_modes_noedid(), and mark the preferred
904 * one using drm_set_preferred_mode().
906 * This function is only called after the @detect hook has indicated
907 * that a sink is connected and when the EDID isn't overridden through
908 * sysfs or the kernel commandline.
910 * This callback is used by the probe helpers in e.g.
911 * drm_helper_probe_single_connector_modes().
913 * To avoid races with concurrent connector state updates, the helper
914 * libraries always call this with the &drm_mode_config.connection_mutex
915 * held. Because of this it's safe to inspect &drm_connector->state.
919 * The number of modes added by calling drm_mode_probed_add().
921 int (*get_modes)(struct drm_connector *connector);
926 * Check to see if anything is attached to the connector. The parameter
927 * force is set to false whilst polling, true when checking the
928 * connector due to a user request. force can be used by the driver to
929 * avoid expensive, destructive operations during automated probing.
931 * This callback is optional, if not implemented the connector will be
932 * considered as always being attached.
934 * This is the atomic version of &drm_connector_funcs.detect.
936 * To avoid races against concurrent connector state updates, the
937 * helper libraries always call this with ctx set to a valid context,
938 * and &drm_mode_config.connection_mutex will always be locked with
939 * the ctx parameter set to this ctx. This allows taking additional
944 * &drm_connector_status indicating the connector's status,
945 * or the error code returned by drm_modeset_lock(), -EDEADLK.
947 int (*detect_ctx)(struct drm_connector *connector,
948 struct drm_modeset_acquire_ctx *ctx,
954 * Callback to validate a mode for a connector, irrespective of the
955 * specific display configuration.
957 * This callback is used by the probe helpers to filter the mode list
958 * (which is usually derived from the EDID data block from the sink).
959 * See e.g. drm_helper_probe_single_connector_modes().
961 * This function is optional.
965 * This only filters the mode list supplied to userspace in the
966 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
967 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
968 * which are also called by the atomic helpers from
969 * drm_atomic_helper_check_modeset(). This allows userspace to force and
970 * ignore sink constraint (like the pixel clock limits in the screen's
971 * EDID), which is useful for e.g. testing, or working around a broken
972 * EDID. Any source hardware constraint (which always need to be
973 * enforced) therefore should be checked in one of the above callbacks,
974 * and not this one here.
976 * To avoid races with concurrent connector state updates, the helper
977 * libraries always call this with the &drm_mode_config.connection_mutex
978 * held. Because of this it's safe to inspect &drm_connector->state.
982 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
985 enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
986 struct drm_display_mode *mode);
990 * This function should select the best encoder for the given connector.
992 * This function is used by both the atomic helpers (in the
993 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
998 * In atomic drivers this function is called in the check phase of an
999 * atomic update. The driver is not allowed to change or inspect
1000 * anything outside of arguments passed-in. Atomic drivers which need to
1001 * inspect dynamic configuration state should instead use
1002 * @atomic_best_encoder.
1004 * You can leave this function to NULL if the connector is only
1005 * attached to a single encoder. In this case, the core will call
1006 * drm_connector_get_single_encoder() for you.
1010 * Encoder that should be used for the given connector and connector
1011 * state, or NULL if no suitable encoder exists. Note that the helpers
1012 * will ensure that encoders aren't used twice, drivers should not check
1015 struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
1018 * @atomic_best_encoder:
1020 * This is the atomic version of @best_encoder for atomic drivers which
1021 * need to select the best encoder depending upon the desired
1022 * configuration and can't select it statically.
1024 * This function is used by drm_atomic_helper_check_modeset().
1025 * If it is not implemented, the core will fallback to @best_encoder
1026 * (or drm_connector_get_single_encoder() if @best_encoder is NULL).
1030 * This function is called in the check phase of an atomic update. The
1031 * driver is not allowed to change anything outside of the free-standing
1032 * state objects passed-in or assembled in the overall &drm_atomic_state
1033 * update tracking structure.
1037 * Encoder that should be used for the given connector and connector
1038 * state, or NULL if no suitable encoder exists. Note that the helpers
1039 * will ensure that encoders aren't used twice, drivers should not check
1042 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
1043 struct drm_connector_state *connector_state);
1048 * This hook is used to validate connector state. This function is
1049 * called from &drm_atomic_helper_check_modeset, and is called when
1050 * a connector property is set, or a modeset on the crtc is forced.
1052 * Because &drm_atomic_helper_check_modeset may be called multiple times,
1053 * this function should handle being called multiple times as well.
1055 * This function is also allowed to inspect any other object's state and
1056 * can add more state objects to the atomic commit if needed. Care must
1057 * be taken though to ensure that state check and compute functions for
1058 * these added states are all called, and derived state in other objects
1059 * all updated. Again the recommendation is to just call check helpers
1060 * until a maximal configuration is reached.
1064 * This function is called in the check phase of an atomic update. The
1065 * driver is not allowed to change anything outside of the free-standing
1066 * state objects passed-in or assembled in the overall &drm_atomic_state
1067 * update tracking structure.
1071 * 0 on success, -EINVAL if the state or the transition can't be
1072 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1073 * attempt to obtain another state object ran into a &drm_modeset_lock
1076 int (*atomic_check)(struct drm_connector *connector,
1077 struct drm_atomic_state *state);
1082 * This hook is to be used by drivers implementing writeback connectors
1083 * that need a point when to commit the writeback job to the hardware.
1084 * The writeback_job to commit is available in
1085 * &drm_connector_state.writeback_job.
1087 * This hook is optional.
1089 * This callback is used by the atomic modeset helpers.
1091 void (*atomic_commit)(struct drm_connector *connector,
1092 struct drm_connector_state *state);
1094 int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
1095 struct drm_writeback_job *job);
1096 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
1097 struct drm_writeback_job *job);
1101 * drm_connector_helper_add - sets the helper vtable for a connector
1102 * @connector: DRM connector
1103 * @funcs: helper vtable to set for @connector
1105 static inline void drm_connector_helper_add(struct drm_connector *connector,
1106 const struct drm_connector_helper_funcs *funcs)
1108 connector->helper_private = funcs;
1112 * struct drm_plane_helper_funcs - helper operations for planes
1114 * These functions are used by the atomic helpers and by the transitional plane
1117 struct drm_plane_helper_funcs {
1121 * This hook is to prepare a framebuffer for scanout by e.g. pinning
1122 * its backing storage or relocating it into a contiguous block of
1123 * VRAM. Other possible preparatory work includes flushing caches.
1125 * This function must not block for outstanding rendering, since it is
1126 * called in the context of the atomic IOCTL even for async commits to
1127 * be able to return any errors to userspace. Instead the recommended
1128 * way is to fill out the &drm_plane_state.fence of the passed-in
1129 * &drm_plane_state. If the driver doesn't support native fences then
1130 * equivalent functionality should be implemented through private
1131 * members in the plane structure.
1133 * Drivers which always have their buffers pinned should use
1134 * drm_gem_fb_prepare_fb() for this hook.
1136 * The helpers will call @cleanup_fb with matching arguments for every
1137 * successful call to this hook.
1139 * This callback is used by the atomic modeset helpers and by the
1140 * transitional plane helpers, but it is optional.
1144 * 0 on success or one of the following negative error codes allowed by
1145 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
1146 * this callback is the only one which can fail an atomic commit,
1147 * everything else must complete successfully.
1149 int (*prepare_fb)(struct drm_plane *plane,
1150 struct drm_plane_state *new_state);
1154 * This hook is called to clean up any resources allocated for the given
1155 * framebuffer and plane configuration in @prepare_fb.
1157 * This callback is used by the atomic modeset helpers and by the
1158 * transitional plane helpers, but it is optional.
1160 void (*cleanup_fb)(struct drm_plane *plane,
1161 struct drm_plane_state *old_state);
1166 * Drivers should check plane specific constraints in this hook.
1168 * When using drm_atomic_helper_check_planes() plane's @atomic_check
1169 * hooks are called before the ones for CRTCs, which allows drivers to
1170 * request shared resources that the CRTC controls here. For more
1171 * complicated dependencies the driver can call the provided check helpers
1172 * multiple times until the computed state has a final configuration and
1173 * everything has been checked.
1175 * This function is also allowed to inspect any other object's state and
1176 * can add more state objects to the atomic commit if needed. Care must
1177 * be taken though to ensure that state check and compute functions for
1178 * these added states are all called, and derived state in other objects
1179 * all updated. Again the recommendation is to just call check helpers
1180 * until a maximal configuration is reached.
1182 * This callback is used by the atomic modeset helpers and by the
1183 * transitional plane helpers, but it is optional.
1187 * This function is called in the check phase of an atomic update. The
1188 * driver is not allowed to change anything outside of the free-standing
1189 * state objects passed-in or assembled in the overall &drm_atomic_state
1190 * update tracking structure.
1194 * 0 on success, -EINVAL if the state or the transition can't be
1195 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1196 * attempt to obtain another state object ran into a &drm_modeset_lock
1199 int (*atomic_check)(struct drm_plane *plane,
1200 struct drm_plane_state *state);
1205 * Drivers should use this function to update the plane state. This
1206 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
1207 * drm_crtc_helper_funcs.atomic_flush callbacks.
1209 * Note that the power state of the display pipe when this function is
1210 * called depends upon the exact helpers and calling sequence the driver
1211 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1212 * the tradeoffs and variants of plane commit helpers.
1214 * This callback is used by the atomic modeset helpers and by the
1215 * transitional plane helpers, but it is optional.
1217 void (*atomic_update)(struct drm_plane *plane,
1218 struct drm_plane_state *old_state);
1222 * Drivers should use this function to unconditionally disable a plane.
1223 * This hook is called in-between the
1224 * &drm_crtc_helper_funcs.atomic_begin and
1225 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
1226 * @atomic_update, which will be called for disabling planes, too, if
1227 * the @atomic_disable hook isn't implemented.
1229 * This hook is also useful to disable planes in preparation of a modeset,
1230 * by calling drm_atomic_helper_disable_planes_on_crtc() from the
1231 * &drm_crtc_helper_funcs.disable hook.
1233 * Note that the power state of the display pipe when this function is
1234 * called depends upon the exact helpers and calling sequence the driver
1235 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1236 * the tradeoffs and variants of plane commit helpers.
1238 * This callback is used by the atomic modeset helpers and by the
1239 * transitional plane helpers, but it is optional.
1241 void (*atomic_disable)(struct drm_plane *plane,
1242 struct drm_plane_state *old_state);
1245 * @atomic_async_check:
1247 * Drivers should set this function pointer to check if the plane state
1248 * can be updated in a async fashion. Here async means "not vblank
1251 * This hook is called by drm_atomic_async_check() to establish if a
1252 * given update can be committed asynchronously, that is, if it can
1253 * jump ahead of the state currently queued for update.
1257 * Return 0 on success and any error returned indicates that the update
1258 * can not be applied in asynchronous manner.
1260 int (*atomic_async_check)(struct drm_plane *plane,
1261 struct drm_plane_state *state);
1264 * @atomic_async_update:
1266 * Drivers should set this function pointer to perform asynchronous
1267 * updates of planes, that is, jump ahead of the currently queued
1268 * state and update the plane. Here async means "not vblank
1271 * This hook is called by drm_atomic_helper_async_commit().
1273 * An async update will happen on legacy cursor updates. An async
1274 * update won't happen if there is an outstanding commit modifying
1277 * Note that unlike &drm_plane_helper_funcs.atomic_update this hook
1278 * takes the new &drm_plane_state as parameter. When doing async_update
1279 * drivers shouldn't replace the &drm_plane_state but update the
1280 * current one with the new plane configurations in the new
1283 * Drivers should also swap the framebuffers between current plane
1284 * state (&drm_plane.state) and new_state.
1285 * This is required since cleanup for async commits is performed on
1286 * the new state, rather than old state like for traditional commits.
1287 * Since we want to give up the reference on the current (old) fb
1288 * instead of our brand new one, swap them in the driver during the
1292 * - It only works for single plane updates
1293 * - Async Pageflips are not supported yet
1294 * - Some hw might still scan out the old buffer until the next
1295 * vblank, however we let go of the fb references as soon as
1296 * we run this hook. For now drivers must implement their own workers
1297 * for deferring if needed, until a common solution is created.
1299 void (*atomic_async_update)(struct drm_plane *plane,
1300 struct drm_plane_state *new_state);
1304 * drm_plane_helper_add - sets the helper vtable for a plane
1306 * @funcs: helper vtable to set for @plane
1308 static inline void drm_plane_helper_add(struct drm_plane *plane,
1309 const struct drm_plane_helper_funcs *funcs)
1311 plane->helper_private = funcs;
1315 * struct drm_mode_config_helper_funcs - global modeset helper operations
1317 * These helper functions are used by the atomic helpers.
1319 struct drm_mode_config_helper_funcs {
1321 * @atomic_commit_tail:
1323 * This hook is used by the default atomic_commit() hook implemented in
1324 * drm_atomic_helper_commit() together with the nonblocking commit
1325 * helpers (see drm_atomic_helper_setup_commit() for a starting point)
1326 * to implement blocking and nonblocking commits easily. It is not used
1327 * by the atomic helpers
1329 * This function is called when the new atomic state has already been
1330 * swapped into the various state pointers. The passed in state
1331 * therefore contains copies of the old/previous state. This hook should
1332 * commit the new state into hardware. Note that the helpers have
1333 * already waited for preceeding atomic commits and fences, but drivers
1334 * can add more waiting calls at the start of their implementation, e.g.
1335 * to wait for driver-internal request for implicit syncing, before
1336 * starting to commit the update to the hardware.
1338 * After the atomic update is committed to the hardware this hook needs
1339 * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate
1340 * to be executed by the hardware, for example using
1341 * drm_atomic_helper_wait_for_vblanks() or
1342 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
1343 * framebuffers using drm_atomic_helper_cleanup_planes().
1345 * When disabling a CRTC this hook _must_ stall for the commit to
1346 * complete. Vblank waits don't work on disabled CRTC, hence the core
1347 * can't take care of this. And it also can't rely on the vblank event,
1348 * since that can be signalled already when the screen shows black,
1349 * which can happen much earlier than the last hardware access needed to
1350 * shut off the display pipeline completely.
1352 * This hook is optional, the default implementation is
1353 * drm_atomic_helper_commit_tail().
1355 void (*atomic_commit_tail)(struct drm_atomic_state *state);