1/*
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>
9 *
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:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
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.
27 */
28
29#ifndef __DRM_MODESET_HELPER_VTABLES_H__
30#define __DRM_MODESET_HELPER_VTABLES_H__
31
32#include <drm/drm_crtc.h>
33#include <drm/drm_encoder.h>
34
35/**
36 * DOC: overview
37 *
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.
43 *
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
46 * helpers.
47 *
48 * To make this clear all the helper vtables are pulled together in this location here.
49 */
50
51enum mode_set_atomic;
52struct drm_writeback_connector;
53struct drm_writeback_job;
54
55/**
56 * struct drm_crtc_helper_funcs - helper operations for CRTCs
57 *
58 * These hooks are used by the legacy CRTC helpers, the transitional plane
59 * helpers and the new atomic modesetting helpers.
60 */
61struct drm_crtc_helper_funcs {
62 /**
63 * @dpms:
64 *
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().
69 *
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.
72 *
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.
77 */
78 void (*dpms)(struct drm_crtc *crtc, int mode);
79
80 /**
81 * @prepare:
82 *
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.
87 *
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
91 * should be used.
92 */
93 void (*prepare)(struct drm_crtc *crtc);
94
95 /**
96 * @commit:
97 *
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
101 * DRM_MODE_DPMS_ON.
102 *
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
106 * should be used.
107 */
108 void (*commit)(struct drm_crtc *crtc);
109
110 /**
111 * @mode_valid:
112 *
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
119 * can be displayed.
120 *
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().
125 *
126 * This function is optional.
127 *
128 * NOTE:
129 *
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.
136 *
137 * RETURNS:
138 *
139 * drm_mode_status Enum
140 */
141 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
142 const struct drm_display_mode *mode);
143
144 /**
145 * @mode_fixup:
146 *
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.
154 *
155 * This function is used by both legacy CRTC helpers and atomic helpers.
156 * With atomic helpers it is optional.
157 *
158 * NOTE:
159 *
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.
165 *
166 * This is in contrast to the legacy CRTC helpers where this was
167 * allowed.
168 *
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.
175 *
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.
181 *
182 * RETURNS:
183 *
184 * True if an acceptable configuration is possible, false if the modeset
185 * operation should be rejected.
186 */
187 bool (*mode_fixup)(struct drm_crtc *crtc,
188 const struct drm_display_mode *mode,
189 struct drm_display_mode *adjusted_mode);
190
191 /**
192 * @mode_set:
193 *
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
198 * modeset support.
199 *
200 * This callback is only used by CRTC helpers and deprecated.
201 *
202 * RETURNS:
203 *
204 * 0 on success or a negative error code on failure.
205 */
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);
209
210 /**
211 * @mode_set_nofb:
212 *
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().
218 *
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.
228 *
229 * This callback is optional.
230 */
231 void (*mode_set_nofb)(struct drm_crtc *crtc);
232
233 /**
234 * @mode_set_base:
235 *
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.
243 *
244 * This callback is only used by the CRTC helpers and deprecated.
245 *
246 * RETURNS:
247 *
248 * 0 on success or a negative error code on failure.
249 */
250 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
251 struct drm_framebuffer *old_fb);
252
253 /**
254 * @mode_set_base_atomic:
255 *
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.
259 *
260 * This callback is optional and only needed for kgdb support in the fbdev
261 * helpers.
262 *
263 * RETURNS:
264 *
265 * 0 on success or a negative error code on failure.
266 */
267 int (*mode_set_base_atomic)(struct drm_crtc *crtc,
268 struct drm_framebuffer *fb, int x, int y,
269 enum mode_set_atomic);
270
271 /**
272 * @disable:
273 *
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().
281 *
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
288 * this one.
289 *
290 * NOTE:
291 *
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).
297 *
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.
301 */
302 void (*disable)(struct drm_crtc *crtc);
303
304 /**
305 * @atomic_check:
306 *
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().
317 *
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.
324 *
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.
331 *
332 * This callback is used by the atomic modeset helpers and by the
333 * transitional plane helpers, but it is optional.
334 *
335 * NOTE:
336 *
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 object passed-in.
340 *
341 * Also beware that userspace can request its own custom modes, neither
342 * core nor helpers filter modes to the list of probe modes reported by
343 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
344 * that modes are filtered consistently put any CRTC constraints and
345 * limits checks into @mode_valid.
346 *
347 * RETURNS:
348 *
349 * 0 on success, -EINVAL if the state or the transition can't be
350 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
351 * attempt to obtain another state object ran into a &drm_modeset_lock
352 * deadlock.
353 */
354 int (*atomic_check)(struct drm_crtc *crtc,
355 struct drm_atomic_state *state);
356
357 /**
358 * @atomic_begin:
359 *
360 * Drivers should prepare for an atomic update of multiple planes on
361 * a CRTC in this hook. Depending upon hardware this might be vblank
362 * evasion, blocking updates by setting bits or doing preparatory work
363 * for e.g. manual update display.
364 *
365 * This hook is called before any plane commit functions are called.
366 *
367 * Note that the power state of the display pipe when this function is
368 * called depends upon the exact helpers and calling sequence the driver
369 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
370 * the tradeoffs and variants of plane commit helpers.
371 *
372 * This callback is used by the atomic modeset helpers and by the
373 * transitional plane helpers, but it is optional.
374 */
375 void (*atomic_begin)(struct drm_crtc *crtc,
376 struct drm_atomic_state *state);
377 /**
378 * @atomic_flush:
379 *
380 * Drivers should finalize an atomic update of multiple planes on
381 * a CRTC in this hook. Depending upon hardware this might include
382 * checking that vblank evasion was successful, unblocking updates by
383 * setting bits or setting the GO bit to flush out all updates.
384 *
385 * Simple hardware or hardware with special requirements can commit and
386 * flush out all updates for all planes from this hook and forgo all the
387 * other commit hooks for plane updates.
388 *
389 * This hook is called after any plane commit functions are called.
390 *
391 * Note that the power state of the display pipe when this function is
392 * called depends upon the exact helpers and calling sequence the driver
393 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
394 * the tradeoffs and variants of plane commit helpers.
395 *
396 * This callback is used by the atomic modeset helpers and by the
397 * transitional plane helpers, but it is optional.
398 */
399 void (*atomic_flush)(struct drm_crtc *crtc,
400 struct drm_atomic_state *state);
401
402 /**
403 * @atomic_enable:
404 *
405 * This callback should be used to enable the CRTC. With the atomic
406 * drivers it is called before all encoders connected to this CRTC are
407 * enabled through the encoder's own &drm_encoder_helper_funcs.enable
408 * hook. If that sequence is too simple drivers can just add their own
409 * hooks and call it from this CRTC callback here by looping over all
410 * encoders connected to it using for_each_encoder_on_crtc().
411 *
412 * This hook is used only by atomic helpers, for symmetry with
413 * @atomic_disable. Atomic drivers don't need to implement it if there's
414 * no need to enable anything at the CRTC level. To ensure that runtime
415 * PM handling (using either DPMS or the new "ACTIVE" property) works
416 * @atomic_enable must be the inverse of @atomic_disable for atomic
417 * drivers.
418 *
419 * This function is optional.
420 */
421 void (*atomic_enable)(struct drm_crtc *crtc,
422 struct drm_atomic_state *state);
423
424 /**
425 * @atomic_disable:
426 *
427 * This callback should be used to disable the CRTC. With the atomic
428 * drivers it is called after all encoders connected to this CRTC have
429 * been shut off already using their own
430 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
431 * simple drivers can just add their own hooks and call it from this
432 * CRTC callback here by looping over all encoders connected to it using
433 * for_each_encoder_on_crtc().
434 *
435 * This hook is used only by atomic helpers. Atomic drivers don't
436 * need to implement it if there's no need to disable anything at the
437 * CRTC level.
438 *
439 * This function is optional.
440 */
441 void (*atomic_disable)(struct drm_crtc *crtc,
442 struct drm_atomic_state *state);
443
444 /**
445 * @get_scanout_position:
446 *
447 * Called by vblank timestamping code.
448 *
449 * Returns the current display scanout position from a CRTC and an
450 * optional accurate ktime_get() timestamp of when the position was
451 * measured. Note that this is a helper callback which is only used
452 * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp()
453 * for the @drm_crtc_funcs.get_vblank_timestamp callback.
454 *
455 * Parameters:
456 *
457 * crtc:
458 * The CRTC.
459 * in_vblank_irq:
460 * True when called from drm_crtc_handle_vblank(). Some drivers
461 * need to apply some workarounds for gpu-specific vblank irq
462 * quirks if the flag is set.
463 * vpos:
464 * Target location for current vertical scanout position.
465 * hpos:
466 * Target location for current horizontal scanout position.
467 * stime:
468 * Target location for timestamp taken immediately before
469 * scanout position query. Can be NULL to skip timestamp.
470 * etime:
471 * Target location for timestamp taken immediately after
472 * scanout position query. Can be NULL to skip timestamp.
473 * mode:
474 * Current display timings.
475 *
476 * Returns vpos as a positive number while in active scanout area.
477 * Returns vpos as a negative number inside vblank, counting the number
478 * of scanlines to go until end of vblank, e.g., -1 means "one scanline
479 * until start of active scanout / end of vblank."
480 *
481 * Returns:
482 *
483 * True on success, false if a reliable scanout position counter could
484 * not be read out.
485 */
486 bool (*get_scanout_position)(struct drm_crtc *crtc,
487 bool in_vblank_irq, int *vpos, int *hpos,
488 ktime_t *stime, ktime_t *etime,
489 const struct drm_display_mode *mode);
490};
491
492/**
493 * drm_crtc_helper_add - sets the helper vtable for a crtc
494 * @crtc: DRM CRTC
495 * @funcs: helper vtable to set for @crtc
496 */
497static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
498 const struct drm_crtc_helper_funcs *funcs)
499{
500 crtc->helper_private = funcs;
501}
502
503/**
504 * struct drm_encoder_helper_funcs - helper operations for encoders
505 *
506 * These hooks are used by the legacy CRTC helpers, the transitional plane
507 * helpers and the new atomic modesetting helpers.
508 */
509struct drm_encoder_helper_funcs {
510 /**
511 * @dpms:
512 *
513 * Callback to control power levels on the encoder. If the mode passed in
514 * is unsupported, the provider must use the next lowest power level.
515 * This is used by the legacy encoder helpers to implement DPMS
516 * functionality in drm_helper_connector_dpms().
517 *
518 * This callback is also used to disable an encoder by calling it with
519 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
520 *
521 * This callback is used by the legacy CRTC helpers. Atomic helpers
522 * also support using this hook for enabling and disabling an encoder to
523 * facilitate transitions to atomic, but it is deprecated. Instead
524 * @enable and @disable should be used.
525 */
526 void (*dpms)(struct drm_encoder *encoder, int mode);
527
528 /**
529 * @mode_valid:
530 *
531 * This callback is used to check if a specific mode is valid in this
532 * encoder. This should be implemented if the encoder has some sort
533 * of restriction in the modes it can display. For example, a given
534 * encoder may be responsible to set a clock value. If the clock can
535 * not produce all the values for the available modes then this callback
536 * can be used to restrict the number of modes to only the ones that
537 * can be displayed.
538 *
539 * This hook is used by the probe helpers to filter the mode list in
540 * drm_helper_probe_single_connector_modes(), and it is used by the
541 * atomic helpers to validate modes supplied by userspace in
542 * drm_atomic_helper_check_modeset().
543 *
544 * This function is optional.
545 *
546 * NOTE:
547 *
548 * Since this function is both called from the check phase of an atomic
549 * commit, and the mode validation in the probe paths it is not allowed
550 * to look at anything else but the passed-in mode, and validate it
551 * against configuration-invariant hardward constraints. Any further
552 * limits which depend upon the configuration can only be checked in
553 * @mode_fixup or @atomic_check.
554 *
555 * RETURNS:
556 *
557 * drm_mode_status Enum
558 */
559 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
560 const struct drm_display_mode *mode);
561
562 /**
563 * @mode_fixup:
564 *
565 * This callback is used to validate and adjust a mode. The parameter
566 * mode is the display mode that should be fed to the next element in
567 * the display chain, either the final &drm_connector or a &drm_bridge.
568 * The parameter adjusted_mode is the input mode the encoder requires. It
569 * can be modified by this callback and does not need to match mode. See
570 * also &drm_crtc_state.adjusted_mode for more details.
571 *
572 * This function is used by both legacy CRTC helpers and atomic helpers.
573 * This hook is optional.
574 *
575 * NOTE:
576 *
577 * This function is called in the check phase of atomic modesets, which
578 * can be aborted for any reason (including on userspace's request to
579 * just check whether a configuration would be possible). Atomic drivers
580 * MUST NOT touch any persistent state (hardware or software) or data
581 * structures except the passed in adjusted_mode parameter.
582 *
583 * This is in contrast to the legacy CRTC helpers where this was
584 * allowed.
585 *
586 * Atomic drivers which need to inspect and adjust more state should
587 * instead use the @atomic_check callback. If @atomic_check is used,
588 * this hook isn't called since @atomic_check allows a strict superset
589 * of the functionality of @mode_fixup.
590 *
591 * Also beware that userspace can request its own custom modes, neither
592 * core nor helpers filter modes to the list of probe modes reported by
593 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
594 * that modes are filtered consistently put any encoder constraints and
595 * limits checks into @mode_valid.
596 *
597 * RETURNS:
598 *
599 * True if an acceptable configuration is possible, false if the modeset
600 * operation should be rejected.
601 */
602 bool (*mode_fixup)(struct drm_encoder *encoder,
603 const struct drm_display_mode *mode,
604 struct drm_display_mode *adjusted_mode);
605
606 /**
607 * @prepare:
608 *
609 * This callback should prepare the encoder for a subsequent modeset,
610 * which in practice means the driver should disable the encoder if it
611 * is running. Most drivers ended up implementing this by calling their
612 * @dpms hook with DRM_MODE_DPMS_OFF.
613 *
614 * This callback is used by the legacy CRTC helpers. Atomic helpers
615 * also support using this hook for disabling an encoder to facilitate
616 * transitions to atomic, but it is deprecated. Instead @disable should
617 * be used.
618 */
619 void (*prepare)(struct drm_encoder *encoder);
620
621 /**
622 * @commit:
623 *
624 * This callback should commit the new mode on the encoder after a modeset,
625 * which in practice means the driver should enable the encoder. Most
626 * drivers ended up implementing this by calling their @dpms hook with
627 * DRM_MODE_DPMS_ON.
628 *
629 * This callback is used by the legacy CRTC helpers. Atomic helpers
630 * also support using this hook for enabling an encoder to facilitate
631 * transitions to atomic, but it is deprecated. Instead @enable should
632 * be used.
633 */
634 void (*commit)(struct drm_encoder *encoder);
635
636 /**
637 * @mode_set:
638 *
639 * This callback is used to update the display mode of an encoder.
640 *
641 * Note that the display pipe is completely off when this function is
642 * called. Drivers which need hardware to be running before they program
643 * the new display mode (because they implement runtime PM) should not
644 * use this hook, because the helper library calls it only once and not
645 * every time the display pipeline is suspend using either DPMS or the
646 * new "ACTIVE" property. Such drivers should instead move all their
647 * encoder setup into the @enable callback.
648 *
649 * This callback is used both by the legacy CRTC helpers and the atomic
650 * modeset helpers. It is optional in the atomic helpers.
651 *
652 * NOTE:
653 *
654 * If the driver uses the atomic modeset helpers and needs to inspect
655 * the connector state or connector display info during mode setting,
656 * @atomic_mode_set can be used instead.
657 */
658 void (*mode_set)(struct drm_encoder *encoder,
659 struct drm_display_mode *mode,
660 struct drm_display_mode *adjusted_mode);
661
662 /**
663 * @atomic_mode_set:
664 *
665 * This callback is used to update the display mode of an encoder.
666 *
667 * Note that the display pipe is completely off when this function is
668 * called. Drivers which need hardware to be running before they program
669 * the new display mode (because they implement runtime PM) should not
670 * use this hook, because the helper library calls it only once and not
671 * every time the display pipeline is suspended using either DPMS or the
672 * new "ACTIVE" property. Such drivers should instead move all their
673 * encoder setup into the @enable callback.
674 *
675 * This callback is used by the atomic modeset helpers in place of the
676 * @mode_set callback, if set by the driver. It is optional and should
677 * be used instead of @mode_set if the driver needs to inspect the
678 * connector state or display info, since there is no direct way to
679 * go from the encoder to the current connector.
680 */
681 void (*atomic_mode_set)(struct drm_encoder *encoder,
682 struct drm_crtc_state *crtc_state,
683 struct drm_connector_state *conn_state);
684
685 /**
686 * @detect:
687 *
688 * This callback can be used by drivers who want to do detection on the
689 * encoder object instead of in connector functions.
690 *
691 * It is not used by any helper and therefore has purely driver-specific
692 * semantics. New drivers shouldn't use this and instead just implement
693 * their own private callbacks.
694 *
695 * FIXME:
696 *
697 * This should just be converted into a pile of driver vfuncs.
698 * Currently radeon, amdgpu and nouveau are using it.
699 */
700 enum drm_connector_status (*detect)(struct drm_encoder *encoder,
701 struct drm_connector *connector);
702
703 /**
704 * @atomic_disable:
705 *
706 * This callback should be used to disable the encoder. With the atomic
707 * drivers it is called before this encoder's CRTC has been shut off
708 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
709 * sequence is too simple drivers can just add their own driver private
710 * encoder hooks and call them from CRTC's callback by looping over all
711 * encoders connected to it using for_each_encoder_on_crtc().
712 *
713 * This callback is a variant of @disable that provides the atomic state
714 * to the driver. If @atomic_disable is implemented, @disable is not
715 * called by the helpers.
716 *
717 * This hook is only used by atomic helpers. Atomic drivers don't need
718 * to implement it if there's no need to disable anything at the encoder
719 * level. To ensure that runtime PM handling (using either DPMS or the
720 * new "ACTIVE" property) works @atomic_disable must be the inverse of
721 * @atomic_enable.
722 */
723 void (*atomic_disable)(struct drm_encoder *encoder,
724 struct drm_atomic_state *state);
725
726 /**
727 * @atomic_enable:
728 *
729 * This callback should be used to enable the encoder. It is called
730 * after this encoder's CRTC has been enabled using their own
731 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
732 * too simple drivers can just add their own driver private encoder
733 * hooks and call them from CRTC's callback by looping over all encoders
734 * connected to it using for_each_encoder_on_crtc().
735 *
736 * This callback is a variant of @enable that provides the atomic state
737 * to the driver. If @atomic_enable is implemented, @enable is not
738 * called by the helpers.
739 *
740 * This hook is only used by atomic helpers, it is the opposite of
741 * @atomic_disable. Atomic drivers don't need to implement it if there's
742 * no need to enable anything at the encoder level. To ensure that
743 * runtime PM handling works @atomic_enable must be the inverse of
744 * @atomic_disable.
745 */
746 void (*atomic_enable)(struct drm_encoder *encoder,
747 struct drm_atomic_state *state);
748
749 /**
750 * @disable:
751 *
752 * This callback should be used to disable the encoder. With the atomic
753 * drivers it is called before this encoder's CRTC has been shut off
754 * using their own &drm_crtc_helper_funcs.disable hook. If that
755 * sequence is too simple drivers can just add their own driver private
756 * encoder hooks and call them from CRTC's callback by looping over all
757 * encoders connected to it using for_each_encoder_on_crtc().
758 *
759 * This hook is used both by legacy CRTC helpers and atomic helpers.
760 * Atomic drivers don't need to implement it if there's no need to
761 * disable anything at the encoder level. To ensure that runtime PM
762 * handling (using either DPMS or the new "ACTIVE" property) works
763 * @disable must be the inverse of @enable for atomic drivers.
764 *
765 * For atomic drivers also consider @atomic_disable and save yourself
766 * from having to read the NOTE below!
767 *
768 * NOTE:
769 *
770 * With legacy CRTC helpers there's a big semantic difference between
771 * @disable and other hooks (like @prepare or @dpms) used to shut down a
772 * encoder: @disable is only called when also logically disabling the
773 * display pipeline and needs to release any resources acquired in
774 * @mode_set (like shared PLLs, or again release pinned framebuffers).
775 *
776 * Therefore @disable must be the inverse of @mode_set plus @commit for
777 * drivers still using legacy CRTC helpers, which is different from the
778 * rules under atomic.
779 */
780 void (*disable)(struct drm_encoder *encoder);
781
782 /**
783 * @enable:
784 *
785 * This callback should be used to enable the encoder. With the atomic
786 * drivers it is called after this encoder's CRTC has been enabled using
787 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
788 * too simple drivers can just add their own driver private encoder
789 * hooks and call them from CRTC's callback by looping over all encoders
790 * connected to it using for_each_encoder_on_crtc().
791 *
792 * This hook is only used by atomic helpers, it is the opposite of
793 * @disable. Atomic drivers don't need to implement it if there's no
794 * need to enable anything at the encoder level. To ensure that
795 * runtime PM handling (using either DPMS or the new "ACTIVE" property)
796 * works @enable must be the inverse of @disable for atomic drivers.
797 */
798 void (*enable)(struct drm_encoder *encoder);
799
800 /**
801 * @atomic_check:
802 *
803 * This callback is used to validate encoder state for atomic drivers.
804 * Since the encoder is the object connecting the CRTC and connector it
805 * gets passed both states, to be able to validate interactions and
806 * update the CRTC to match what the encoder needs for the requested
807 * connector.
808 *
809 * Since this provides a strict superset of the functionality of
810 * @mode_fixup (the requested and adjusted modes are both available
811 * through the passed in &struct drm_crtc_state) @mode_fixup is not
812 * called when @atomic_check is implemented.
813 *
814 * This function is used by the atomic helpers, but it is optional.
815 *
816 * NOTE:
817 *
818 * This function is called in the check phase of an atomic update. The
819 * driver is not allowed to change anything outside of the free-standing
820 * state objects passed-in or assembled in the overall &drm_atomic_state
821 * update tracking structure.
822 *
823 * Also beware that userspace can request its own custom modes, neither
824 * core nor helpers filter modes to the list of probe modes reported by
825 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
826 * that modes are filtered consistently put any encoder constraints and
827 * limits checks into @mode_valid.
828 *
829 * RETURNS:
830 *
831 * 0 on success, -EINVAL if the state or the transition can't be
832 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
833 * attempt to obtain another state object ran into a &drm_modeset_lock
834 * deadlock.
835 */
836 int (*atomic_check)(struct drm_encoder *encoder,
837 struct drm_crtc_state *crtc_state,
838 struct drm_connector_state *conn_state);
839};
840
841/**
842 * drm_encoder_helper_add - sets the helper vtable for an encoder
843 * @encoder: DRM encoder
844 * @funcs: helper vtable to set for @encoder
845 */
846static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
847 const struct drm_encoder_helper_funcs *funcs)
848{
849 encoder->helper_private = funcs;
850}
851
852/**
853 * struct drm_connector_helper_funcs - helper operations for connectors
854 *
855 * These functions are used by the atomic and legacy modeset helpers and by the
856 * probe helpers.
857 */
858struct drm_connector_helper_funcs {
859 /**
860 * @get_modes:
861 *
862 * This function should fill in all modes currently valid for the sink
863 * into the &drm_connector.probed_modes list. It should also update the
864 * EDID property by calling drm_connector_update_edid_property().
865 *
866 * The usual way to implement this is to cache the EDID retrieved in the
867 * probe callback somewhere in the driver-private connector structure.
868 * In this function drivers then parse the modes in the EDID and add
869 * them by calling drm_add_edid_modes(). But connectors that drive a
870 * fixed panel can also manually add specific modes using
871 * drm_mode_probed_add(). Drivers which manually add modes should also
872 * make sure that the &drm_connector.display_info,
873 * &drm_connector.width_mm and &drm_connector.height_mm fields are
874 * filled in.
875 *
876 * Note that the caller function will automatically add standard VESA
877 * DMT modes up to 1024x768 if the .get_modes() helper operation returns
878 * no mode and if the connector status is connector_status_connected or
879 * connector_status_unknown. There is no need to call
880 * drm_add_modes_noedid() manually in that case.
881 *
882 * Virtual drivers that just want some standard VESA mode with a given
883 * resolution can call drm_add_modes_noedid(), and mark the preferred
884 * one using drm_set_preferred_mode().
885 *
886 * This function is only called after the @detect hook has indicated
887 * that a sink is connected and when the EDID isn't overridden through
888 * sysfs or the kernel commandline.
889 *
890 * This callback is used by the probe helpers in e.g.
891 * drm_helper_probe_single_connector_modes().
892 *
893 * To avoid races with concurrent connector state updates, the helper
894 * libraries always call this with the &drm_mode_config.connection_mutex
895 * held. Because of this it's safe to inspect &drm_connector->state.
896 *
897 * RETURNS:
898 *
899 * The number of modes added by calling drm_mode_probed_add().
900 */
901 int (*get_modes)(struct drm_connector *connector);
902
903 /**
904 * @detect_ctx:
905 *
906 * Check to see if anything is attached to the connector. The parameter
907 * force is set to false whilst polling, true when checking the
908 * connector due to a user request. force can be used by the driver to
909 * avoid expensive, destructive operations during automated probing.
910 *
911 * This callback is optional, if not implemented the connector will be
912 * considered as always being attached.
913 *
914 * This is the atomic version of &drm_connector_funcs.detect.
915 *
916 * To avoid races against concurrent connector state updates, the
917 * helper libraries always call this with ctx set to a valid context,
918 * and &drm_mode_config.connection_mutex will always be locked with
919 * the ctx parameter set to this ctx. This allows taking additional
920 * locks as required.
921 *
922 * RETURNS:
923 *
924 * &drm_connector_status indicating the connector's status,
925 * or the error code returned by drm_modeset_lock(), -EDEADLK.
926 */
927 int (*detect_ctx)(struct drm_connector *connector,
928 struct drm_modeset_acquire_ctx *ctx,
929 bool force);
930
931 /**
932 * @mode_valid:
933 *
934 * Callback to validate a mode for a connector, irrespective of the
935 * specific display configuration.
936 *
937 * This callback is used by the probe helpers to filter the mode list
938 * (which is usually derived from the EDID data block from the sink).
939 * See e.g. drm_helper_probe_single_connector_modes().
940 *
941 * This function is optional.
942 *
943 * NOTE:
944 *
945 * This only filters the mode list supplied to userspace in the
946 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
947 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
948 * which are also called by the atomic helpers from
949 * drm_atomic_helper_check_modeset(). This allows userspace to force and
950 * ignore sink constraint (like the pixel clock limits in the screen's
951 * EDID), which is useful for e.g. testing, or working around a broken
952 * EDID. Any source hardware constraint (which always need to be
953 * enforced) therefore should be checked in one of the above callbacks,
954 * and not this one here.
955 *
956 * To avoid races with concurrent connector state updates, the helper
957 * libraries always call this with the &drm_mode_config.connection_mutex
958 * held. Because of this it's safe to inspect &drm_connector->state.
959 *
960 * RETURNS:
961 *
962 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
963 * drm_mode_status.
964 */
965 enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
966 struct drm_display_mode *mode);
967
968 /**
969 * @mode_valid_ctx:
970 *
971 * Callback to validate a mode for a connector, irrespective of the
972 * specific display configuration.
973 *
974 * This callback is used by the probe helpers to filter the mode list
975 * (which is usually derived from the EDID data block from the sink).
976 * See e.g. drm_helper_probe_single_connector_modes().
977 *
978 * This function is optional, and is the atomic version of
979 * &drm_connector_helper_funcs.mode_valid.
980 *
981 * To allow for accessing the atomic state of modesetting objects, the
982 * helper libraries always call this with ctx set to a valid context,
983 * and &drm_mode_config.connection_mutex will always be locked with
984 * the ctx parameter set to @ctx. This allows for taking additional
985 * locks as required.
986 *
987 * Even though additional locks may be acquired, this callback is
988 * still expected not to take any constraints into account which would
989 * be influenced by the currently set display state - such constraints
990 * should be handled in the driver's atomic check. For example, if a
991 * connector shares display bandwidth with other connectors then it
992 * would be ok to validate the minimum bandwidth requirement of a mode
993 * against the maximum possible bandwidth of the connector. But it
994 * wouldn't be ok to take the current bandwidth usage of other
995 * connectors into account, as this would change depending on the
996 * display state.
997 *
998 * Returns:
999 * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote
1000 * the &enum drm_mode_status value to @status, or a negative error
1001 * code otherwise.
1002 *
1003 */
1004 int (*mode_valid_ctx)(struct drm_connector *connector,
1005 struct drm_display_mode *mode,
1006 struct drm_modeset_acquire_ctx *ctx,
1007 enum drm_mode_status *status);
1008
1009 /**
1010 * @best_encoder:
1011 *
1012 * This function should select the best encoder for the given connector.
1013 *
1014 * This function is used by both the atomic helpers (in the
1015 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
1016 * helpers.
1017 *
1018 * NOTE:
1019 *
1020 * In atomic drivers this function is called in the check phase of an
1021 * atomic update. The driver is not allowed to change or inspect
1022 * anything outside of arguments passed-in. Atomic drivers which need to
1023 * inspect dynamic configuration state should instead use
1024 * @atomic_best_encoder.
1025 *
1026 * You can leave this function to NULL if the connector is only
1027 * attached to a single encoder. In this case, the core will call
1028 * drm_connector_get_single_encoder() for you.
1029 *
1030 * RETURNS:
1031 *
1032 * Encoder that should be used for the given connector and connector
1033 * state, or NULL if no suitable encoder exists. Note that the helpers
1034 * will ensure that encoders aren't used twice, drivers should not check
1035 * for this.
1036 */
1037 struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
1038
1039 /**
1040 * @atomic_best_encoder:
1041 *
1042 * This is the atomic version of @best_encoder for atomic drivers which
1043 * need to select the best encoder depending upon the desired
1044 * configuration and can't select it statically.
1045 *
1046 * This function is used by drm_atomic_helper_check_modeset().
1047 * If it is not implemented, the core will fallback to @best_encoder
1048 * (or drm_connector_get_single_encoder() if @best_encoder is NULL).
1049 *
1050 * NOTE:
1051 *
1052 * This function is called in the check phase of an atomic update. The
1053 * driver is not allowed to change anything outside of the
1054 * &drm_atomic_state update tracking structure passed in.
1055 *
1056 * RETURNS:
1057 *
1058 * Encoder that should be used for the given connector and connector
1059 * state, or NULL if no suitable encoder exists. Note that the helpers
1060 * will ensure that encoders aren't used twice, drivers should not check
1061 * for this.
1062 */
1063 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
1064 struct drm_atomic_state *state);
1065
1066 /**
1067 * @atomic_check:
1068 *
1069 * This hook is used to validate connector state. This function is
1070 * called from &drm_atomic_helper_check_modeset, and is called when
1071 * a connector property is set, or a modeset on the crtc is forced.
1072 *
1073 * Because &drm_atomic_helper_check_modeset may be called multiple times,
1074 * this function should handle being called multiple times as well.
1075 *
1076 * This function is also allowed to inspect any other object's state and
1077 * can add more state objects to the atomic commit if needed. Care must
1078 * be taken though to ensure that state check and compute functions for
1079 * these added states are all called, and derived state in other objects
1080 * all updated. Again the recommendation is to just call check helpers
1081 * until a maximal configuration is reached.
1082 *
1083 * NOTE:
1084 *
1085 * This function is called in the check phase of an atomic update. The
1086 * driver is not allowed to change anything outside of the free-standing
1087 * state objects passed-in or assembled in the overall &drm_atomic_state
1088 * update tracking structure.
1089 *
1090 * RETURNS:
1091 *
1092 * 0 on success, -EINVAL if the state or the transition can't be
1093 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1094 * attempt to obtain another state object ran into a &drm_modeset_lock
1095 * deadlock.
1096 */
1097 int (*atomic_check)(struct drm_connector *connector,
1098 struct drm_atomic_state *state);
1099
1100 /**
1101 * @atomic_commit:
1102 *
1103 * This hook is to be used by drivers implementing writeback connectors
1104 * that need a point when to commit the writeback job to the hardware.
1105 * The writeback_job to commit is available in the new connector state,
1106 * in &drm_connector_state.writeback_job.
1107 *
1108 * This hook is optional.
1109 *
1110 * This callback is used by the atomic modeset helpers.
1111 */
1112 void (*atomic_commit)(struct drm_connector *connector,
1113 struct drm_atomic_state *state);
1114
1115 /**
1116 * @prepare_writeback_job:
1117 *
1118 * As writeback jobs contain a framebuffer, drivers may need to
1119 * prepare and clean them up the same way they can prepare and
1120 * clean up framebuffers for planes. This optional connector operation
1121 * is used to support the preparation of writeback jobs. The job
1122 * prepare operation is called from drm_atomic_helper_prepare_planes()
1123 * for struct &drm_writeback_connector connectors only.
1124 *
1125 * This operation is optional.
1126 *
1127 * This callback is used by the atomic modeset helpers.
1128 */
1129 int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
1130 struct drm_writeback_job *job);
1131 /**
1132 * @cleanup_writeback_job:
1133 *
1134 * This optional connector operation is used to support the
1135 * cleanup of writeback jobs. The job cleanup operation is called
1136 * from the existing drm_writeback_cleanup_job() function, invoked
1137 * both when destroying the job as part of an aborted commit, or when
1138 * the job completes.
1139 *
1140 * This operation is optional.
1141 *
1142 * This callback is used by the atomic modeset helpers.
1143 */
1144 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
1145 struct drm_writeback_job *job);
1146};
1147
1148/**
1149 * drm_connector_helper_add - sets the helper vtable for a connector
1150 * @connector: DRM connector
1151 * @funcs: helper vtable to set for @connector
1152 */
1153static inline void drm_connector_helper_add(struct drm_connector *connector,
1154 const struct drm_connector_helper_funcs *funcs)
1155{
1156 connector->helper_private = funcs;
1157}
1158
1159/**
1160 * struct drm_plane_helper_funcs - helper operations for planes
1161 *
1162 * These functions are used by the atomic helpers and by the transitional plane
1163 * helpers.
1164 */
1165struct drm_plane_helper_funcs {
1166 /**
1167 * @prepare_fb:
1168 *
1169 * This hook is to prepare a framebuffer for scanout by e.g. pinning
1170 * its backing storage or relocating it into a contiguous block of
1171 * VRAM. Other possible preparatory work includes flushing caches.
1172 *
1173 * This function must not block for outstanding rendering, since it is
1174 * called in the context of the atomic IOCTL even for async commits to
1175 * be able to return any errors to userspace. Instead the recommended
1176 * way is to fill out the &drm_plane_state.fence of the passed-in
1177 * &drm_plane_state. If the driver doesn't support native fences then
1178 * equivalent functionality should be implemented through private
1179 * members in the plane structure.
1180 *
1181 * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook
1182 * set drm_gem_plane_helper_prepare_fb() is called automatically to
1183 * implement this. Other drivers which need additional plane processing
1184 * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb
1185 * hook.
1186 *
1187 * The helpers will call @cleanup_fb with matching arguments for every
1188 * successful call to this hook.
1189 *
1190 * This callback is used by the atomic modeset helpers and by the
1191 * transitional plane helpers, but it is optional.
1192 *
1193 * RETURNS:
1194 *
1195 * 0 on success or one of the following negative error codes allowed by
1196 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
1197 * this callback is the only one which can fail an atomic commit,
1198 * everything else must complete successfully.
1199 */
1200 int (*prepare_fb)(struct drm_plane *plane,
1201 struct drm_plane_state *new_state);
1202 /**
1203 * @cleanup_fb:
1204 *
1205 * This hook is called to clean up any resources allocated for the given
1206 * framebuffer and plane configuration in @prepare_fb.
1207 *
1208 * This callback is used by the atomic modeset helpers and by the
1209 * transitional plane helpers, but it is optional.
1210 */
1211 void (*cleanup_fb)(struct drm_plane *plane,
1212 struct drm_plane_state *old_state);
1213
1214 /**
1215 * @atomic_check:
1216 *
1217 * Drivers should check plane specific constraints in this hook.
1218 *
1219 * When using drm_atomic_helper_check_planes() plane's @atomic_check
1220 * hooks are called before the ones for CRTCs, which allows drivers to
1221 * request shared resources that the CRTC controls here. For more
1222 * complicated dependencies the driver can call the provided check helpers
1223 * multiple times until the computed state has a final configuration and
1224 * everything has been checked.
1225 *
1226 * This function is also allowed to inspect any other object's state and
1227 * can add more state objects to the atomic commit if needed. Care must
1228 * be taken though to ensure that state check and compute functions for
1229 * these added states are all called, and derived state in other objects
1230 * all updated. Again the recommendation is to just call check helpers
1231 * until a maximal configuration is reached.
1232 *
1233 * This callback is used by the atomic modeset helpers and by the
1234 * transitional plane helpers, but it is optional.
1235 *
1236 * NOTE:
1237 *
1238 * This function is called in the check phase of an atomic update. The
1239 * driver is not allowed to change anything outside of the
1240 * &drm_atomic_state update tracking structure.
1241 *
1242 * RETURNS:
1243 *
1244 * 0 on success, -EINVAL if the state or the transition can't be
1245 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1246 * attempt to obtain another state object ran into a &drm_modeset_lock
1247 * deadlock.
1248 */
1249 int (*atomic_check)(struct drm_plane *plane,
1250 struct drm_atomic_state *state);
1251
1252 /**
1253 * @atomic_update:
1254 *
1255 * Drivers should use this function to update the plane state. This
1256 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
1257 * drm_crtc_helper_funcs.atomic_flush callbacks.
1258 *
1259 * Note that the power state of the display pipe when this function is
1260 * called depends upon the exact helpers and calling sequence the driver
1261 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1262 * the tradeoffs and variants of plane commit helpers.
1263 *
1264 * This callback is used by the atomic modeset helpers and by the
1265 * transitional plane helpers, but it is optional.
1266 */
1267 void (*atomic_update)(struct drm_plane *plane,
1268 struct drm_atomic_state *state);
1269 /**
1270 * @atomic_disable:
1271 *
1272 * Drivers should use this function to unconditionally disable a plane.
1273 * This hook is called in-between the
1274 * &drm_crtc_helper_funcs.atomic_begin and
1275 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
1276 * @atomic_update, which will be called for disabling planes, too, if
1277 * the @atomic_disable hook isn't implemented.
1278 *
1279 * This hook is also useful to disable planes in preparation of a modeset,
1280 * by calling drm_atomic_helper_disable_planes_on_crtc() from the
1281 * &drm_crtc_helper_funcs.disable hook.
1282 *
1283 * Note that the power state of the display pipe when this function is
1284 * called depends upon the exact helpers and calling sequence the driver
1285 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1286 * the tradeoffs and variants of plane commit helpers.
1287 *
1288 * This callback is used by the atomic modeset helpers and by the
1289 * transitional plane helpers, but it is optional.
1290 */
1291 void (*atomic_disable)(struct drm_plane *plane,
1292 struct drm_atomic_state *state);
1293
1294 /**
1295 * @atomic_async_check:
1296 *
1297 * Drivers should set this function pointer to check if the plane's
1298 * atomic state can be updated in a async fashion. Here async means
1299 * "not vblank synchronized".
1300 *
1301 * This hook is called by drm_atomic_async_check() to establish if a
1302 * given update can be committed asynchronously, that is, if it can
1303 * jump ahead of the state currently queued for update.
1304 *
1305 * RETURNS:
1306 *
1307 * Return 0 on success and any error returned indicates that the update
1308 * can not be applied in asynchronous manner.
1309 */
1310 int (*atomic_async_check)(struct drm_plane *plane,
1311 struct drm_atomic_state *state);
1312
1313 /**
1314 * @atomic_async_update:
1315 *
1316 * Drivers should set this function pointer to perform asynchronous
1317 * updates of planes, that is, jump ahead of the currently queued
1318 * state and update the plane. Here async means "not vblank
1319 * synchronized".
1320 *
1321 * This hook is called by drm_atomic_helper_async_commit().
1322 *
1323 * An async update will happen on legacy cursor updates. An async
1324 * update won't happen if there is an outstanding commit modifying
1325 * the same plane.
1326 *
1327 * When doing async_update drivers shouldn't replace the
1328 * &drm_plane_state but update the current one with the new plane
1329 * configurations in the new plane_state.
1330 *
1331 * Drivers should also swap the framebuffers between current plane
1332 * state (&drm_plane.state) and new_state.
1333 * This is required since cleanup for async commits is performed on
1334 * the new state, rather than old state like for traditional commits.
1335 * Since we want to give up the reference on the current (old) fb
1336 * instead of our brand new one, swap them in the driver during the
1337 * async commit.
1338 *
1339 * FIXME:
1340 * - It only works for single plane updates
1341 * - Async Pageflips are not supported yet
1342 * - Some hw might still scan out the old buffer until the next
1343 * vblank, however we let go of the fb references as soon as
1344 * we run this hook. For now drivers must implement their own workers
1345 * for deferring if needed, until a common solution is created.
1346 */
1347 void (*atomic_async_update)(struct drm_plane *plane,
1348 struct drm_atomic_state *state);
1349};
1350
1351/**
1352 * drm_plane_helper_add - sets the helper vtable for a plane
1353 * @plane: DRM plane
1354 * @funcs: helper vtable to set for @plane
1355 */
1356static inline void drm_plane_helper_add(struct drm_plane *plane,
1357 const struct drm_plane_helper_funcs *funcs)
1358{
1359 plane->helper_private = funcs;
1360}
1361
1362/**
1363 * struct drm_mode_config_helper_funcs - global modeset helper operations
1364 *
1365 * These helper functions are used by the atomic helpers.
1366 */
1367struct drm_mode_config_helper_funcs {
1368 /**
1369 * @atomic_commit_tail:
1370 *
1371 * This hook is used by the default atomic_commit() hook implemented in
1372 * drm_atomic_helper_commit() together with the nonblocking commit
1373 * helpers (see drm_atomic_helper_setup_commit() for a starting point)
1374 * to implement blocking and nonblocking commits easily. It is not used
1375 * by the atomic helpers
1376 *
1377 * This function is called when the new atomic state has already been
1378 * swapped into the various state pointers. The passed in state
1379 * therefore contains copies of the old/previous state. This hook should
1380 * commit the new state into hardware. Note that the helpers have
1381 * already waited for preceeding atomic commits and fences, but drivers
1382 * can add more waiting calls at the start of their implementation, e.g.
1383 * to wait for driver-internal request for implicit syncing, before
1384 * starting to commit the update to the hardware.
1385 *
1386 * After the atomic update is committed to the hardware this hook needs
1387 * to call drm_atomic_helper_commit_hw_done(). Then wait for the update
1388 * to be executed by the hardware, for example using
1389 * drm_atomic_helper_wait_for_vblanks() or
1390 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
1391 * framebuffers using drm_atomic_helper_cleanup_planes().
1392 *
1393 * When disabling a CRTC this hook _must_ stall for the commit to
1394 * complete. Vblank waits don't work on disabled CRTC, hence the core
1395 * can't take care of this. And it also can't rely on the vblank event,
1396 * since that can be signalled already when the screen shows black,
1397 * which can happen much earlier than the last hardware access needed to
1398 * shut off the display pipeline completely.
1399 *
1400 * This hook is optional, the default implementation is
1401 * drm_atomic_helper_commit_tail().
1402 */
1403 void (*atomic_commit_tail)(struct drm_atomic_state *state);
1404
1405 /**
1406 * @atomic_commit_setup:
1407 *
1408 * This hook is used by the default atomic_commit() hook implemented in
1409 * drm_atomic_helper_commit() together with the nonblocking helpers (see
1410 * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It
1411 * is not used by the atomic helpers.
1412 *
1413 * This function is called at the end of
1414 * drm_atomic_helper_setup_commit(), so once the commit has been
1415 * properly setup across the generic DRM object states. It allows
1416 * drivers to do some additional commit tracking that isn't related to a
1417 * CRTC, plane or connector, tracked in a &drm_private_obj structure.
1418 *
1419 * Note that the documentation of &drm_private_obj has more details on
1420 * how one should implement this.
1421 *
1422 * This hook is optional.
1423 */
1424 int (*atomic_commit_setup)(struct drm_atomic_state *state);
1425};
1426
1427#endif
1428

source code of linux/include/drm/drm_modeset_helper_vtables.h