Loading...
Note: File does not exist in v3.1.
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 objects passed-in or assembled in the overall &drm_atomic_state
340 * update tracking structure.
341 *
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.
347 *
348 * RETURNS:
349 *
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
353 * deadlock.
354 */
355 int (*atomic_check)(struct drm_crtc *crtc,
356 struct drm_crtc_state *state);
357
358 /**
359 * @atomic_begin:
360 *
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.
365 *
366 * This hook is called before any plane commit functions are called.
367 *
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.
372 *
373 * This callback is used by the atomic modeset helpers and by the
374 * transitional plane helpers, but it is optional.
375 */
376 void (*atomic_begin)(struct drm_crtc *crtc,
377 struct drm_crtc_state *old_crtc_state);
378 /**
379 * @atomic_flush:
380 *
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.
385 *
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.
389 *
390 * This hook is called after any plane commit functions are called.
391 *
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.
396 *
397 * This callback is used by the atomic modeset helpers and by the
398 * transitional plane helpers, but it is optional.
399 */
400 void (*atomic_flush)(struct drm_crtc *crtc,
401 struct drm_crtc_state *old_crtc_state);
402
403 /**
404 * @atomic_enable:
405 *
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().
412 *
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
418 * drivers.
419 *
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.
423 *
424 * This function is optional.
425 */
426 void (*atomic_enable)(struct drm_crtc *crtc,
427 struct drm_crtc_state *old_crtc_state);
428
429 /**
430 * @atomic_disable:
431 *
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().
439 *
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
442 * CRTC level.
443 *
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
447 * of @disable.
448 *
449 * This function is optional.
450 */
451 void (*atomic_disable)(struct drm_crtc *crtc,
452 struct drm_crtc_state *old_crtc_state);
453
454 /**
455 * @get_scanout_position:
456 *
457 * Called by vblank timestamping code.
458 *
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.
464 *
465 * Parameters:
466 *
467 * crtc:
468 * The CRTC.
469 * in_vblank_irq:
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.
473 * vpos:
474 * Target location for current vertical scanout position.
475 * hpos:
476 * Target location for current horizontal scanout position.
477 * stime:
478 * Target location for timestamp taken immediately before
479 * scanout position query. Can be NULL to skip timestamp.
480 * etime:
481 * Target location for timestamp taken immediately after
482 * scanout position query. Can be NULL to skip timestamp.
483 * mode:
484 * Current display timings.
485 *
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."
490 *
491 * Returns:
492 *
493 * True on success, false if a reliable scanout position counter could
494 * not be read out.
495 */
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);
500};
501
502/**
503 * drm_crtc_helper_add - sets the helper vtable for a crtc
504 * @crtc: DRM CRTC
505 * @funcs: helper vtable to set for @crtc
506 */
507static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
508 const struct drm_crtc_helper_funcs *funcs)
509{
510 crtc->helper_private = funcs;
511}
512
513/**
514 * struct drm_encoder_helper_funcs - helper operations for encoders
515 *
516 * These hooks are used by the legacy CRTC helpers, the transitional plane
517 * helpers and the new atomic modesetting helpers.
518 */
519struct drm_encoder_helper_funcs {
520 /**
521 * @dpms:
522 *
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().
527 *
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.
530 *
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.
535 */
536 void (*dpms)(struct drm_encoder *encoder, int mode);
537
538 /**
539 * @mode_valid:
540 *
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
547 * can be displayed.
548 *
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().
553 *
554 * This function is optional.
555 *
556 * NOTE:
557 *
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.
564 *
565 * RETURNS:
566 *
567 * drm_mode_status Enum
568 */
569 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
570 const struct drm_display_mode *mode);
571
572 /**
573 * @mode_fixup:
574 *
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.
581 *
582 * This function is used by both legacy CRTC helpers and atomic helpers.
583 * This hook is optional.
584 *
585 * NOTE:
586 *
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.
592 *
593 * This is in contrast to the legacy CRTC helpers where this was
594 * allowed.
595 *
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.
600 *
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.
606 *
607 * RETURNS:
608 *
609 * True if an acceptable configuration is possible, false if the modeset
610 * operation should be rejected.
611 */
612 bool (*mode_fixup)(struct drm_encoder *encoder,
613 const struct drm_display_mode *mode,
614 struct drm_display_mode *adjusted_mode);
615
616 /**
617 * @prepare:
618 *
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.
623 *
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
627 * be used.
628 */
629 void (*prepare)(struct drm_encoder *encoder);
630
631 /**
632 * @commit:
633 *
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
637 * DRM_MODE_DPMS_ON.
638 *
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
642 * be used.
643 */
644 void (*commit)(struct drm_encoder *encoder);
645
646 /**
647 * @mode_set:
648 *
649 * This callback is used to update the display mode of an encoder.
650 *
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.
658 *
659 * This callback is used both by the legacy CRTC helpers and the atomic
660 * modeset helpers. It is optional in the atomic helpers.
661 *
662 * NOTE:
663 *
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.
667 */
668 void (*mode_set)(struct drm_encoder *encoder,
669 struct drm_display_mode *mode,
670 struct drm_display_mode *adjusted_mode);
671
672 /**
673 * @atomic_mode_set:
674 *
675 * This callback is used to update the display mode of an encoder.
676 *
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.
684 *
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.
690 */
691 void (*atomic_mode_set)(struct drm_encoder *encoder,
692 struct drm_crtc_state *crtc_state,
693 struct drm_connector_state *conn_state);
694
695 /**
696 * @detect:
697 *
698 * This callback can be used by drivers who want to do detection on the
699 * encoder object instead of in connector functions.
700 *
701 * It is not used by any helper and therefore has purely driver-specific
702 * semantics. New drivers shouldn't use this and instead just implement
703 * their own private callbacks.
704 *
705 * FIXME:
706 *
707 * This should just be converted into a pile of driver vfuncs.
708 * Currently radeon, amdgpu and nouveau are using it.
709 */
710 enum drm_connector_status (*detect)(struct drm_encoder *encoder,
711 struct drm_connector *connector);
712
713 /**
714 * @atomic_disable:
715 *
716 * This callback should be used to disable the encoder. With the atomic
717 * drivers it is called before this encoder's CRTC has been shut off
718 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
719 * sequence is too simple drivers can just add their own driver private
720 * encoder hooks and call them from CRTC's callback by looping over all
721 * encoders connected to it using for_each_encoder_on_crtc().
722 *
723 * This callback is a variant of @disable that provides the atomic state
724 * to the driver. If @atomic_disable is implemented, @disable is not
725 * called by the helpers.
726 *
727 * This hook is only used by atomic helpers. Atomic drivers don't need
728 * to implement it if there's no need to disable anything at the encoder
729 * level. To ensure that runtime PM handling (using either DPMS or the
730 * new "ACTIVE" property) works @atomic_disable must be the inverse of
731 * @atomic_enable.
732 */
733 void (*atomic_disable)(struct drm_encoder *encoder,
734 struct drm_atomic_state *state);
735
736 /**
737 * @atomic_enable:
738 *
739 * This callback should be used to enable the encoder. It is called
740 * after this encoder's CRTC has been enabled using their own
741 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
742 * too simple drivers can just add their own driver private encoder
743 * hooks and call them from CRTC's callback by looping over all encoders
744 * connected to it using for_each_encoder_on_crtc().
745 *
746 * This callback is a variant of @enable that provides the atomic state
747 * to the driver. If @atomic_enable is implemented, @enable is not
748 * called by the helpers.
749 *
750 * This hook is only used by atomic helpers, it is the opposite of
751 * @atomic_disable. Atomic drivers don't need to implement it if there's
752 * no need to enable anything at the encoder level. To ensure that
753 * runtime PM handling works @atomic_enable must be the inverse of
754 * @atomic_disable.
755 */
756 void (*atomic_enable)(struct drm_encoder *encoder,
757 struct drm_atomic_state *state);
758
759 /**
760 * @disable:
761 *
762 * This callback should be used to disable the encoder. With the atomic
763 * drivers it is called before this encoder's CRTC has been shut off
764 * using their own &drm_crtc_helper_funcs.disable hook. If that
765 * sequence is too simple drivers can just add their own driver private
766 * encoder hooks and call them from CRTC's callback by looping over all
767 * encoders connected to it using for_each_encoder_on_crtc().
768 *
769 * This hook is used both by legacy CRTC helpers and atomic helpers.
770 * Atomic drivers don't need to implement it if there's no need to
771 * disable anything at the encoder level. To ensure that runtime PM
772 * handling (using either DPMS or the new "ACTIVE" property) works
773 * @disable must be the inverse of @enable for atomic drivers.
774 *
775 * For atomic drivers also consider @atomic_disable and save yourself
776 * from having to read the NOTE below!
777 *
778 * NOTE:
779 *
780 * With legacy CRTC helpers there's a big semantic difference between
781 * @disable and other hooks (like @prepare or @dpms) used to shut down a
782 * encoder: @disable is only called when also logically disabling the
783 * display pipeline and needs to release any resources acquired in
784 * @mode_set (like shared PLLs, or again release pinned framebuffers).
785 *
786 * Therefore @disable must be the inverse of @mode_set plus @commit for
787 * drivers still using legacy CRTC helpers, which is different from the
788 * rules under atomic.
789 */
790 void (*disable)(struct drm_encoder *encoder);
791
792 /**
793 * @enable:
794 *
795 * This callback should be used to enable the encoder. With the atomic
796 * drivers it is called after this encoder's CRTC has been enabled using
797 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
798 * too simple drivers can just add their own driver private encoder
799 * hooks and call them from CRTC's callback by looping over all encoders
800 * connected to it using for_each_encoder_on_crtc().
801 *
802 * This hook is only used by atomic helpers, it is the opposite of
803 * @disable. Atomic drivers don't need to implement it if there's no
804 * need to enable anything at the encoder level. To ensure that
805 * runtime PM handling (using either DPMS or the new "ACTIVE" property)
806 * works @enable must be the inverse of @disable for atomic drivers.
807 */
808 void (*enable)(struct drm_encoder *encoder);
809
810 /**
811 * @atomic_check:
812 *
813 * This callback is used to validate encoder state for atomic drivers.
814 * Since the encoder is the object connecting the CRTC and connector it
815 * gets passed both states, to be able to validate interactions and
816 * update the CRTC to match what the encoder needs for the requested
817 * connector.
818 *
819 * Since this provides a strict superset of the functionality of
820 * @mode_fixup (the requested and adjusted modes are both available
821 * through the passed in &struct drm_crtc_state) @mode_fixup is not
822 * called when @atomic_check is implemented.
823 *
824 * This function is used by the atomic helpers, but it is optional.
825 *
826 * NOTE:
827 *
828 * This function is called in the check phase of an atomic update. The
829 * driver is not allowed to change anything outside of the free-standing
830 * state objects passed-in or assembled in the overall &drm_atomic_state
831 * update tracking structure.
832 *
833 * Also beware that userspace can request its own custom modes, neither
834 * core nor helpers filter modes to the list of probe modes reported by
835 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
836 * that modes are filtered consistently put any encoder constraints and
837 * limits checks into @mode_valid.
838 *
839 * RETURNS:
840 *
841 * 0 on success, -EINVAL if the state or the transition can't be
842 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
843 * attempt to obtain another state object ran into a &drm_modeset_lock
844 * deadlock.
845 */
846 int (*atomic_check)(struct drm_encoder *encoder,
847 struct drm_crtc_state *crtc_state,
848 struct drm_connector_state *conn_state);
849};
850
851/**
852 * drm_encoder_helper_add - sets the helper vtable for an encoder
853 * @encoder: DRM encoder
854 * @funcs: helper vtable to set for @encoder
855 */
856static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
857 const struct drm_encoder_helper_funcs *funcs)
858{
859 encoder->helper_private = funcs;
860}
861
862/**
863 * struct drm_connector_helper_funcs - helper operations for connectors
864 *
865 * These functions are used by the atomic and legacy modeset helpers and by the
866 * probe helpers.
867 */
868struct drm_connector_helper_funcs {
869 /**
870 * @get_modes:
871 *
872 * This function should fill in all modes currently valid for the sink
873 * into the &drm_connector.probed_modes list. It should also update the
874 * EDID property by calling drm_connector_update_edid_property().
875 *
876 * The usual way to implement this is to cache the EDID retrieved in the
877 * probe callback somewhere in the driver-private connector structure.
878 * In this function drivers then parse the modes in the EDID and add
879 * them by calling drm_add_edid_modes(). But connectors that driver a
880 * fixed panel can also manually add specific modes using
881 * drm_mode_probed_add(). Drivers which manually add modes should also
882 * make sure that the &drm_connector.display_info,
883 * &drm_connector.width_mm and &drm_connector.height_mm fields are
884 * filled in.
885 *
886 * Virtual drivers that just want some standard VESA mode with a given
887 * resolution can call drm_add_modes_noedid(), and mark the preferred
888 * one using drm_set_preferred_mode().
889 *
890 * This function is only called after the @detect hook has indicated
891 * that a sink is connected and when the EDID isn't overridden through
892 * sysfs or the kernel commandline.
893 *
894 * This callback is used by the probe helpers in e.g.
895 * drm_helper_probe_single_connector_modes().
896 *
897 * To avoid races with concurrent connector state updates, the helper
898 * libraries always call this with the &drm_mode_config.connection_mutex
899 * held. Because of this it's safe to inspect &drm_connector->state.
900 *
901 * RETURNS:
902 *
903 * The number of modes added by calling drm_mode_probed_add().
904 */
905 int (*get_modes)(struct drm_connector *connector);
906
907 /**
908 * @detect_ctx:
909 *
910 * Check to see if anything is attached to the connector. The parameter
911 * force is set to false whilst polling, true when checking the
912 * connector due to a user request. force can be used by the driver to
913 * avoid expensive, destructive operations during automated probing.
914 *
915 * This callback is optional, if not implemented the connector will be
916 * considered as always being attached.
917 *
918 * This is the atomic version of &drm_connector_funcs.detect.
919 *
920 * To avoid races against concurrent connector state updates, the
921 * helper libraries always call this with ctx set to a valid context,
922 * and &drm_mode_config.connection_mutex will always be locked with
923 * the ctx parameter set to this ctx. This allows taking additional
924 * locks as required.
925 *
926 * RETURNS:
927 *
928 * &drm_connector_status indicating the connector's status,
929 * or the error code returned by drm_modeset_lock(), -EDEADLK.
930 */
931 int (*detect_ctx)(struct drm_connector *connector,
932 struct drm_modeset_acquire_ctx *ctx,
933 bool force);
934
935 /**
936 * @mode_valid:
937 *
938 * Callback to validate a mode for a connector, irrespective of the
939 * specific display configuration.
940 *
941 * This callback is used by the probe helpers to filter the mode list
942 * (which is usually derived from the EDID data block from the sink).
943 * See e.g. drm_helper_probe_single_connector_modes().
944 *
945 * This function is optional.
946 *
947 * NOTE:
948 *
949 * This only filters the mode list supplied to userspace in the
950 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
951 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
952 * which are also called by the atomic helpers from
953 * drm_atomic_helper_check_modeset(). This allows userspace to force and
954 * ignore sink constraint (like the pixel clock limits in the screen's
955 * EDID), which is useful for e.g. testing, or working around a broken
956 * EDID. Any source hardware constraint (which always need to be
957 * enforced) therefore should be checked in one of the above callbacks,
958 * and not this one here.
959 *
960 * To avoid races with concurrent connector state updates, the helper
961 * libraries always call this with the &drm_mode_config.connection_mutex
962 * held. Because of this it's safe to inspect &drm_connector->state.
963 *
964 * RETURNS:
965 *
966 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
967 * drm_mode_status.
968 */
969 enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
970 struct drm_display_mode *mode);
971
972 /**
973 * @mode_valid_ctx:
974 *
975 * Callback to validate a mode for a connector, irrespective of the
976 * specific display configuration.
977 *
978 * This callback is used by the probe helpers to filter the mode list
979 * (which is usually derived from the EDID data block from the sink).
980 * See e.g. drm_helper_probe_single_connector_modes().
981 *
982 * This function is optional, and is the atomic version of
983 * &drm_connector_helper_funcs.mode_valid.
984 *
985 * To allow for accessing the atomic state of modesetting objects, the
986 * helper libraries always call this with ctx set to a valid context,
987 * and &drm_mode_config.connection_mutex will always be locked with
988 * the ctx parameter set to @ctx. This allows for taking additional
989 * locks as required.
990 *
991 * Even though additional locks may be acquired, this callback is
992 * still expected not to take any constraints into account which would
993 * be influenced by the currently set display state - such constraints
994 * should be handled in the driver's atomic check. For example, if a
995 * connector shares display bandwidth with other connectors then it
996 * would be ok to validate the minimum bandwidth requirement of a mode
997 * against the maximum possible bandwidth of the connector. But it
998 * wouldn't be ok to take the current bandwidth usage of other
999 * connectors into account, as this would change depending on the
1000 * display state.
1001 *
1002 * Returns:
1003 * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote
1004 * the &enum drm_mode_status value to @status, or a negative error
1005 * code otherwise.
1006 *
1007 */
1008 int (*mode_valid_ctx)(struct drm_connector *connector,
1009 struct drm_display_mode *mode,
1010 struct drm_modeset_acquire_ctx *ctx,
1011 enum drm_mode_status *status);
1012
1013 /**
1014 * @best_encoder:
1015 *
1016 * This function should select the best encoder for the given connector.
1017 *
1018 * This function is used by both the atomic helpers (in the
1019 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
1020 * helpers.
1021 *
1022 * NOTE:
1023 *
1024 * In atomic drivers this function is called in the check phase of an
1025 * atomic update. The driver is not allowed to change or inspect
1026 * anything outside of arguments passed-in. Atomic drivers which need to
1027 * inspect dynamic configuration state should instead use
1028 * @atomic_best_encoder.
1029 *
1030 * You can leave this function to NULL if the connector is only
1031 * attached to a single encoder. In this case, the core will call
1032 * drm_connector_get_single_encoder() for you.
1033 *
1034 * RETURNS:
1035 *
1036 * Encoder that should be used for the given connector and connector
1037 * state, or NULL if no suitable encoder exists. Note that the helpers
1038 * will ensure that encoders aren't used twice, drivers should not check
1039 * for this.
1040 */
1041 struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
1042
1043 /**
1044 * @atomic_best_encoder:
1045 *
1046 * This is the atomic version of @best_encoder for atomic drivers which
1047 * need to select the best encoder depending upon the desired
1048 * configuration and can't select it statically.
1049 *
1050 * This function is used by drm_atomic_helper_check_modeset().
1051 * If it is not implemented, the core will fallback to @best_encoder
1052 * (or drm_connector_get_single_encoder() if @best_encoder is NULL).
1053 *
1054 * NOTE:
1055 *
1056 * This function is called in the check phase of an atomic update. The
1057 * driver is not allowed to change anything outside of the free-standing
1058 * state objects passed-in or assembled in the overall &drm_atomic_state
1059 * update tracking structure.
1060 *
1061 * RETURNS:
1062 *
1063 * Encoder that should be used for the given connector and connector
1064 * state, or NULL if no suitable encoder exists. Note that the helpers
1065 * will ensure that encoders aren't used twice, drivers should not check
1066 * for this.
1067 */
1068 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
1069 struct drm_connector_state *connector_state);
1070
1071 /**
1072 * @atomic_check:
1073 *
1074 * This hook is used to validate connector state. This function is
1075 * called from &drm_atomic_helper_check_modeset, and is called when
1076 * a connector property is set, or a modeset on the crtc is forced.
1077 *
1078 * Because &drm_atomic_helper_check_modeset may be called multiple times,
1079 * this function should handle being called multiple times as well.
1080 *
1081 * This function is also allowed to inspect any other object's state and
1082 * can add more state objects to the atomic commit if needed. Care must
1083 * be taken though to ensure that state check and compute functions for
1084 * these added states are all called, and derived state in other objects
1085 * all updated. Again the recommendation is to just call check helpers
1086 * until a maximal configuration is reached.
1087 *
1088 * NOTE:
1089 *
1090 * This function is called in the check phase of an atomic update. The
1091 * driver is not allowed to change anything outside of the free-standing
1092 * state objects passed-in or assembled in the overall &drm_atomic_state
1093 * update tracking structure.
1094 *
1095 * RETURNS:
1096 *
1097 * 0 on success, -EINVAL if the state or the transition can't be
1098 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1099 * attempt to obtain another state object ran into a &drm_modeset_lock
1100 * deadlock.
1101 */
1102 int (*atomic_check)(struct drm_connector *connector,
1103 struct drm_atomic_state *state);
1104
1105 /**
1106 * @atomic_commit:
1107 *
1108 * This hook is to be used by drivers implementing writeback connectors
1109 * that need a point when to commit the writeback job to the hardware.
1110 * The writeback_job to commit is available in
1111 * &drm_connector_state.writeback_job.
1112 *
1113 * This hook is optional.
1114 *
1115 * This callback is used by the atomic modeset helpers.
1116 */
1117 void (*atomic_commit)(struct drm_connector *connector,
1118 struct drm_connector_state *state);
1119
1120 /**
1121 * @prepare_writeback_job:
1122 *
1123 * As writeback jobs contain a framebuffer, drivers may need to
1124 * prepare and clean them up the same way they can prepare and
1125 * clean up framebuffers for planes. This optional connector operation
1126 * is used to support the preparation of writeback jobs. The job
1127 * prepare operation is called from drm_atomic_helper_prepare_planes()
1128 * for struct &drm_writeback_connector connectors only.
1129 *
1130 * This operation is optional.
1131 *
1132 * This callback is used by the atomic modeset helpers.
1133 */
1134 int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
1135 struct drm_writeback_job *job);
1136 /**
1137 * @cleanup_writeback_job:
1138 *
1139 * This optional connector operation is used to support the
1140 * cleanup of writeback jobs. The job cleanup operation is called
1141 * from the existing drm_writeback_cleanup_job() function, invoked
1142 * both when destroying the job as part of an aborted commit, or when
1143 * the job completes.
1144 *
1145 * This operation is optional.
1146 *
1147 * This callback is used by the atomic modeset helpers.
1148 */
1149 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
1150 struct drm_writeback_job *job);
1151};
1152
1153/**
1154 * drm_connector_helper_add - sets the helper vtable for a connector
1155 * @connector: DRM connector
1156 * @funcs: helper vtable to set for @connector
1157 */
1158static inline void drm_connector_helper_add(struct drm_connector *connector,
1159 const struct drm_connector_helper_funcs *funcs)
1160{
1161 connector->helper_private = funcs;
1162}
1163
1164/**
1165 * struct drm_plane_helper_funcs - helper operations for planes
1166 *
1167 * These functions are used by the atomic helpers and by the transitional plane
1168 * helpers.
1169 */
1170struct drm_plane_helper_funcs {
1171 /**
1172 * @prepare_fb:
1173 *
1174 * This hook is to prepare a framebuffer for scanout by e.g. pinning
1175 * its backing storage or relocating it into a contiguous block of
1176 * VRAM. Other possible preparatory work includes flushing caches.
1177 *
1178 * This function must not block for outstanding rendering, since it is
1179 * called in the context of the atomic IOCTL even for async commits to
1180 * be able to return any errors to userspace. Instead the recommended
1181 * way is to fill out the &drm_plane_state.fence of the passed-in
1182 * &drm_plane_state. If the driver doesn't support native fences then
1183 * equivalent functionality should be implemented through private
1184 * members in the plane structure.
1185 *
1186 * Drivers which always have their buffers pinned should use
1187 * drm_gem_fb_prepare_fb() for this hook.
1188 *
1189 * The helpers will call @cleanup_fb with matching arguments for every
1190 * successful call to this hook.
1191 *
1192 * This callback is used by the atomic modeset helpers and by the
1193 * transitional plane helpers, but it is optional.
1194 *
1195 * RETURNS:
1196 *
1197 * 0 on success or one of the following negative error codes allowed by
1198 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
1199 * this callback is the only one which can fail an atomic commit,
1200 * everything else must complete successfully.
1201 */
1202 int (*prepare_fb)(struct drm_plane *plane,
1203 struct drm_plane_state *new_state);
1204 /**
1205 * @cleanup_fb:
1206 *
1207 * This hook is called to clean up any resources allocated for the given
1208 * framebuffer and plane configuration in @prepare_fb.
1209 *
1210 * This callback is used by the atomic modeset helpers and by the
1211 * transitional plane helpers, but it is optional.
1212 */
1213 void (*cleanup_fb)(struct drm_plane *plane,
1214 struct drm_plane_state *old_state);
1215
1216 /**
1217 * @atomic_check:
1218 *
1219 * Drivers should check plane specific constraints in this hook.
1220 *
1221 * When using drm_atomic_helper_check_planes() plane's @atomic_check
1222 * hooks are called before the ones for CRTCs, which allows drivers to
1223 * request shared resources that the CRTC controls here. For more
1224 * complicated dependencies the driver can call the provided check helpers
1225 * multiple times until the computed state has a final configuration and
1226 * everything has been checked.
1227 *
1228 * This function is also allowed to inspect any other object's state and
1229 * can add more state objects to the atomic commit if needed. Care must
1230 * be taken though to ensure that state check and compute functions for
1231 * these added states are all called, and derived state in other objects
1232 * all updated. Again the recommendation is to just call check helpers
1233 * until a maximal configuration is reached.
1234 *
1235 * This callback is used by the atomic modeset helpers and by the
1236 * transitional plane helpers, but it is optional.
1237 *
1238 * NOTE:
1239 *
1240 * This function is called in the check phase of an atomic update. The
1241 * driver is not allowed to change anything outside of the free-standing
1242 * state objects passed-in or assembled in the overall &drm_atomic_state
1243 * update tracking structure.
1244 *
1245 * RETURNS:
1246 *
1247 * 0 on success, -EINVAL if the state or the transition can't be
1248 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1249 * attempt to obtain another state object ran into a &drm_modeset_lock
1250 * deadlock.
1251 */
1252 int (*atomic_check)(struct drm_plane *plane,
1253 struct drm_plane_state *state);
1254
1255 /**
1256 * @atomic_update:
1257 *
1258 * Drivers should use this function to update the plane state. This
1259 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
1260 * drm_crtc_helper_funcs.atomic_flush callbacks.
1261 *
1262 * Note that the power state of the display pipe when this function is
1263 * called depends upon the exact helpers and calling sequence the driver
1264 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1265 * the tradeoffs and variants of plane commit helpers.
1266 *
1267 * This callback is used by the atomic modeset helpers and by the
1268 * transitional plane helpers, but it is optional.
1269 */
1270 void (*atomic_update)(struct drm_plane *plane,
1271 struct drm_plane_state *old_state);
1272 /**
1273 * @atomic_disable:
1274 *
1275 * Drivers should use this function to unconditionally disable a plane.
1276 * This hook is called in-between the
1277 * &drm_crtc_helper_funcs.atomic_begin and
1278 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
1279 * @atomic_update, which will be called for disabling planes, too, if
1280 * the @atomic_disable hook isn't implemented.
1281 *
1282 * This hook is also useful to disable planes in preparation of a modeset,
1283 * by calling drm_atomic_helper_disable_planes_on_crtc() from the
1284 * &drm_crtc_helper_funcs.disable hook.
1285 *
1286 * Note that the power state of the display pipe when this function is
1287 * called depends upon the exact helpers and calling sequence the driver
1288 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1289 * the tradeoffs and variants of plane commit helpers.
1290 *
1291 * This callback is used by the atomic modeset helpers and by the
1292 * transitional plane helpers, but it is optional.
1293 */
1294 void (*atomic_disable)(struct drm_plane *plane,
1295 struct drm_plane_state *old_state);
1296
1297 /**
1298 * @atomic_async_check:
1299 *
1300 * Drivers should set this function pointer to check if the plane state
1301 * can be updated in a async fashion. Here async means "not vblank
1302 * synchronized".
1303 *
1304 * This hook is called by drm_atomic_async_check() to establish if a
1305 * given update can be committed asynchronously, that is, if it can
1306 * jump ahead of the state currently queued for update.
1307 *
1308 * RETURNS:
1309 *
1310 * Return 0 on success and any error returned indicates that the update
1311 * can not be applied in asynchronous manner.
1312 */
1313 int (*atomic_async_check)(struct drm_plane *plane,
1314 struct drm_plane_state *state);
1315
1316 /**
1317 * @atomic_async_update:
1318 *
1319 * Drivers should set this function pointer to perform asynchronous
1320 * updates of planes, that is, jump ahead of the currently queued
1321 * state and update the plane. Here async means "not vblank
1322 * synchronized".
1323 *
1324 * This hook is called by drm_atomic_helper_async_commit().
1325 *
1326 * An async update will happen on legacy cursor updates. An async
1327 * update won't happen if there is an outstanding commit modifying
1328 * the same plane.
1329 *
1330 * Note that unlike &drm_plane_helper_funcs.atomic_update this hook
1331 * takes the new &drm_plane_state as parameter. When doing async_update
1332 * drivers shouldn't replace the &drm_plane_state but update the
1333 * current one with the new plane configurations in the new
1334 * plane_state.
1335 *
1336 * Drivers should also swap the framebuffers between current plane
1337 * state (&drm_plane.state) and new_state.
1338 * This is required since cleanup for async commits is performed on
1339 * the new state, rather than old state like for traditional commits.
1340 * Since we want to give up the reference on the current (old) fb
1341 * instead of our brand new one, swap them in the driver during the
1342 * async commit.
1343 *
1344 * FIXME:
1345 * - It only works for single plane updates
1346 * - Async Pageflips are not supported yet
1347 * - Some hw might still scan out the old buffer until the next
1348 * vblank, however we let go of the fb references as soon as
1349 * we run this hook. For now drivers must implement their own workers
1350 * for deferring if needed, until a common solution is created.
1351 */
1352 void (*atomic_async_update)(struct drm_plane *plane,
1353 struct drm_plane_state *new_state);
1354};
1355
1356/**
1357 * drm_plane_helper_add - sets the helper vtable for a plane
1358 * @plane: DRM plane
1359 * @funcs: helper vtable to set for @plane
1360 */
1361static inline void drm_plane_helper_add(struct drm_plane *plane,
1362 const struct drm_plane_helper_funcs *funcs)
1363{
1364 plane->helper_private = funcs;
1365}
1366
1367/**
1368 * struct drm_mode_config_helper_funcs - global modeset helper operations
1369 *
1370 * These helper functions are used by the atomic helpers.
1371 */
1372struct drm_mode_config_helper_funcs {
1373 /**
1374 * @atomic_commit_tail:
1375 *
1376 * This hook is used by the default atomic_commit() hook implemented in
1377 * drm_atomic_helper_commit() together with the nonblocking commit
1378 * helpers (see drm_atomic_helper_setup_commit() for a starting point)
1379 * to implement blocking and nonblocking commits easily. It is not used
1380 * by the atomic helpers
1381 *
1382 * This function is called when the new atomic state has already been
1383 * swapped into the various state pointers. The passed in state
1384 * therefore contains copies of the old/previous state. This hook should
1385 * commit the new state into hardware. Note that the helpers have
1386 * already waited for preceeding atomic commits and fences, but drivers
1387 * can add more waiting calls at the start of their implementation, e.g.
1388 * to wait for driver-internal request for implicit syncing, before
1389 * starting to commit the update to the hardware.
1390 *
1391 * After the atomic update is committed to the hardware this hook needs
1392 * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate
1393 * to be executed by the hardware, for example using
1394 * drm_atomic_helper_wait_for_vblanks() or
1395 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
1396 * framebuffers using drm_atomic_helper_cleanup_planes().
1397 *
1398 * When disabling a CRTC this hook _must_ stall for the commit to
1399 * complete. Vblank waits don't work on disabled CRTC, hence the core
1400 * can't take care of this. And it also can't rely on the vblank event,
1401 * since that can be signalled already when the screen shows black,
1402 * which can happen much earlier than the last hardware access needed to
1403 * shut off the display pipeline completely.
1404 *
1405 * This hook is optional, the default implementation is
1406 * drm_atomic_helper_commit_tail().
1407 */
1408 void (*atomic_commit_tail)(struct drm_atomic_state *state);
1409};
1410
1411#endif