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
51 struct drm_scanout_buffer;
52 struct drm_writeback_connector;
53 struct drm_writeback_job;
54
55 enum mode_set_atomic {
56 LEAVE_ATOMIC_MODE_SET,
57 ENTER_ATOMIC_MODE_SET,
58 };
59
60 /**
61 * struct drm_crtc_helper_funcs - helper operations for CRTCs
62 *
63 * These hooks are used by the legacy CRTC helpers and the new atomic
64 * modesetting helpers.
65 */
66 struct drm_crtc_helper_funcs {
67 /**
68 * @dpms:
69 *
70 * Callback to control power levels on the CRTC. If the mode passed in
71 * is unsupported, the provider must use the next lowest power level.
72 * This is used by the legacy CRTC helpers to implement DPMS
73 * functionality in drm_helper_connector_dpms().
74 *
75 * This callback is also used to disable a CRTC by calling it with
76 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
77 *
78 * This callback is used by the legacy CRTC helpers. Atomic helpers
79 * also support using this hook for enabling and disabling a CRTC to
80 * facilitate transitions to atomic, but it is deprecated. Instead
81 * @atomic_enable and @atomic_disable should be used.
82 */
83 void (*dpms)(struct drm_crtc *crtc, int mode);
84
85 /**
86 * @prepare:
87 *
88 * This callback should prepare the CRTC for a subsequent modeset, which
89 * in practice means the driver should disable the CRTC if it is
90 * running. Most drivers ended up implementing this by calling their
91 * @dpms hook with DRM_MODE_DPMS_OFF.
92 *
93 * This callback is used by the legacy CRTC helpers. Atomic helpers
94 * also support using this hook for disabling a CRTC to facilitate
95 * transitions to atomic, but it is deprecated. Instead @atomic_disable
96 * should be used.
97 */
98 void (*prepare)(struct drm_crtc *crtc);
99
100 /**
101 * @commit:
102 *
103 * This callback should commit the new mode on the CRTC after a modeset,
104 * which in practice means the driver should enable the CRTC. Most
105 * drivers ended up implementing this by calling their @dpms hook with
106 * DRM_MODE_DPMS_ON.
107 *
108 * This callback is used by the legacy CRTC helpers. Atomic helpers
109 * also support using this hook for enabling a CRTC to facilitate
110 * transitions to atomic, but it is deprecated. Instead @atomic_enable
111 * should be used.
112 */
113 void (*commit)(struct drm_crtc *crtc);
114
115 /**
116 * @mode_valid:
117 *
118 * This callback is used to check if a specific mode is valid in this
119 * crtc. This should be implemented if the crtc has some sort of
120 * restriction in the modes it can display. For example, a given crtc
121 * may be responsible to set a clock value. If the clock can not
122 * produce all the values for the available modes then this callback
123 * can be used to restrict the number of modes to only the ones that
124 * can be displayed.
125 *
126 * This hook is used by the probe helpers to filter the mode list in
127 * drm_helper_probe_single_connector_modes(), and it is used by the
128 * atomic helpers to validate modes supplied by userspace in
129 * drm_atomic_helper_check_modeset().
130 *
131 * This function is optional.
132 *
133 * NOTE:
134 *
135 * Since this function is both called from the check phase of an atomic
136 * commit, and the mode validation in the probe paths it is not allowed
137 * to look at anything else but the passed-in mode, and validate it
138 * against configuration-invariant hardware constraints. Any further
139 * limits which depend upon the configuration can only be checked in
140 * @mode_fixup or @atomic_check.
141 *
142 * RETURNS:
143 *
144 * drm_mode_status Enum
145 */
146 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
147 const struct drm_display_mode *mode);
148
149 /**
150 * @mode_fixup:
151 *
152 * This callback is used to validate a mode. The parameter mode is the
153 * display mode that userspace requested, adjusted_mode is the mode the
154 * encoders need to be fed with. Note that this is the inverse semantics
155 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
156 * vfunc. If the CRTC cannot support the requested conversion from mode
157 * to adjusted_mode it should reject the modeset. See also
158 * &drm_crtc_state.adjusted_mode for more details.
159 *
160 * This function is used by both legacy CRTC helpers and atomic helpers.
161 * With atomic helpers it is optional.
162 *
163 * NOTE:
164 *
165 * This function is called in the check phase of atomic modesets, which
166 * can be aborted for any reason (including on userspace's request to
167 * just check whether a configuration would be possible). Atomic drivers
168 * MUST NOT touch any persistent state (hardware or software) or data
169 * structures except the passed in adjusted_mode parameter.
170 *
171 * This is in contrast to the legacy CRTC helpers where this was
172 * allowed.
173 *
174 * Atomic drivers which need to inspect and adjust more state should
175 * instead use the @atomic_check callback, but note that they're not
176 * perfectly equivalent: @mode_valid is called from
177 * drm_atomic_helper_check_modeset(), but @atomic_check is called from
178 * drm_atomic_helper_check_planes(), because originally it was meant for
179 * plane update checks only.
180 *
181 * Also beware that userspace can request its own custom modes, neither
182 * core nor helpers filter modes to the list of probe modes reported by
183 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
184 * that modes are filtered consistently put any CRTC constraints and
185 * limits checks into @mode_valid.
186 *
187 * RETURNS:
188 *
189 * True if an acceptable configuration is possible, false if the modeset
190 * operation should be rejected.
191 */
192 bool (*mode_fixup)(struct drm_crtc *crtc,
193 const struct drm_display_mode *mode,
194 struct drm_display_mode *adjusted_mode);
195
196 /**
197 * @mode_set:
198 *
199 * This callback is used by the legacy CRTC helpers to set a new mode,
200 * position and framebuffer. Since it ties the primary plane to every
201 * mode change it is incompatible with universal plane support. And
202 * since it can't update other planes it's incompatible with atomic
203 * modeset support.
204 *
205 * This callback is only used by CRTC helpers and deprecated.
206 *
207 * RETURNS:
208 *
209 * 0 on success or a negative error code on failure.
210 */
211 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
212 struct drm_display_mode *adjusted_mode, int x, int y,
213 struct drm_framebuffer *old_fb);
214
215 /**
216 * @mode_set_nofb:
217 *
218 * This callback is used to update the display mode of a CRTC without
219 * changing anything of the primary plane configuration. This fits the
220 * requirement of atomic and hence is used by the atomic helpers.
221 *
222 * Note that the display pipe is completely off when this function is
223 * called. Atomic drivers which need hardware to be running before they
224 * program the new display mode (e.g. because they implement runtime PM)
225 * should not use this hook. This is because the helper library calls
226 * this hook only once per mode change and not every time the display
227 * pipeline is suspended using either DPMS or the new "ACTIVE" property.
228 * Which means register values set in this callback might get reset when
229 * the CRTC is suspended, but not restored. Such drivers should instead
230 * move all their CRTC setup into the @atomic_enable callback.
231 *
232 * This callback is optional.
233 */
234 void (*mode_set_nofb)(struct drm_crtc *crtc);
235
236 /**
237 * @mode_set_base:
238 *
239 * This callback is used by the legacy CRTC helpers to set a new
240 * framebuffer and scanout position. It is optional and used as an
241 * optimized fast-path instead of a full mode set operation with all the
242 * resulting flickering. If it is not present
243 * drm_crtc_helper_set_config() will fall back to a full modeset, using
244 * the @mode_set callback. Since it can't update other planes it's
245 * incompatible with atomic modeset support.
246 *
247 * This callback is only used by the CRTC helpers and deprecated.
248 *
249 * RETURNS:
250 *
251 * 0 on success or a negative error code on failure.
252 */
253 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
254 struct drm_framebuffer *old_fb);
255
256 /**
257 * @mode_set_base_atomic:
258 *
259 * This callback is used by the fbdev helpers to set a new framebuffer
260 * and scanout without sleeping, i.e. from an atomic calling context. It
261 * is only used to implement kgdb support.
262 *
263 * This callback is optional and only needed for kgdb support in the fbdev
264 * helpers.
265 *
266 * RETURNS:
267 *
268 * 0 on success or a negative error code on failure.
269 */
270 int (*mode_set_base_atomic)(struct drm_crtc *crtc,
271 struct drm_framebuffer *fb, int x, int y,
272 enum mode_set_atomic);
273
274 /**
275 * @disable:
276 *
277 * This callback should be used to disable the CRTC. With the atomic
278 * drivers it is called after all encoders connected to this CRTC have
279 * been shut off already using their own
280 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
281 * simple drivers can just add their own hooks and call it from this
282 * CRTC callback here by looping over all encoders connected to it using
283 * for_each_encoder_on_crtc().
284 *
285 * This hook is used both by legacy CRTC helpers and atomic helpers.
286 * Atomic drivers don't need to implement it if there's no need to
287 * disable anything at the CRTC level. To ensure that runtime PM
288 * handling (using either DPMS or the new "ACTIVE" property) works
289 * @disable must be the inverse of @atomic_enable for atomic drivers.
290 * Atomic drivers should consider to use @atomic_disable instead of
291 * this one.
292 *
293 * NOTE:
294 *
295 * With legacy CRTC helpers there's a big semantic difference between
296 * @disable and other hooks (like @prepare or @dpms) used to shut down a
297 * CRTC: @disable is only called when also logically disabling the
298 * display pipeline and needs to release any resources acquired in
299 * @mode_set (like shared PLLs, or again release pinned framebuffers).
300 *
301 * Therefore @disable must be the inverse of @mode_set plus @commit for
302 * drivers still using legacy CRTC helpers, which is different from the
303 * rules under atomic.
304 */
305 void (*disable)(struct drm_crtc *crtc);
306
307 /**
308 * @atomic_check:
309 *
310 * Drivers should check plane-update related CRTC constraints in this
311 * hook. They can also check mode related limitations but need to be
312 * aware of the calling order, since this hook is used by
313 * drm_atomic_helper_check_planes() whereas the preparations needed to
314 * check output routing and the display mode is done in
315 * drm_atomic_helper_check_modeset(). Therefore drivers that want to
316 * check output routing and display mode constraints in this callback
317 * must ensure that drm_atomic_helper_check_modeset() has been called
318 * beforehand. This is calling order used by the default helper
319 * implementation in drm_atomic_helper_check().
320 *
321 * When using drm_atomic_helper_check_planes() this hook is called
322 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which
323 * allows drivers to assign shared resources requested by planes in this
324 * callback here. For more complicated dependencies the driver can call
325 * the provided check helpers multiple times until the computed state
326 * has a final configuration and everything has been checked.
327 *
328 * This function is also allowed to inspect any other object's state and
329 * can add more state objects to the atomic commit if needed. Care must
330 * be taken though to ensure that state check and compute functions for
331 * these added states are all called, and derived state in other objects
332 * all updated. Again the recommendation is to just call check helpers
333 * until a maximal configuration is reached.
334 *
335 * This callback is used by the atomic modeset helpers, but it is
336 * optional.
337 *
338 * NOTE:
339 *
340 * This function is called in the check phase of an atomic update. The
341 * driver is not allowed to change anything outside of the free-standing
342 * state object passed-in.
343 *
344 * Also beware that userspace can request its own custom modes, neither
345 * core nor helpers filter modes to the list of probe modes reported by
346 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
347 * that modes are filtered consistently put any CRTC constraints and
348 * limits checks into @mode_valid.
349 *
350 * RETURNS:
351 *
352 * 0 on success, -EINVAL if the state or the transition can't be
353 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
354 * attempt to obtain another state object ran into a &drm_modeset_lock
355 * deadlock.
356 */
357 int (*atomic_check)(struct drm_crtc *crtc,
358 struct drm_atomic_state *state);
359
360 /**
361 * @atomic_begin:
362 *
363 * Drivers should prepare for an atomic update of multiple planes on
364 * a CRTC in this hook. Depending upon hardware this might be vblank
365 * evasion, blocking updates by setting bits or doing preparatory work
366 * for e.g. manual update display.
367 *
368 * This hook is called before any plane commit functions are called.
369 *
370 * Note that the power state of the display pipe when this function is
371 * called depends upon the exact helpers and calling sequence the driver
372 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
373 * the tradeoffs and variants of plane commit helpers.
374 *
375 * This callback is used by the atomic modeset helpers, but it is
376 * optional.
377 */
378 void (*atomic_begin)(struct drm_crtc *crtc,
379 struct drm_atomic_state *state);
380 /**
381 * @atomic_flush:
382 *
383 * Drivers should finalize an atomic update of multiple planes on
384 * a CRTC in this hook. Depending upon hardware this might include
385 * checking that vblank evasion was successful, unblocking updates by
386 * setting bits or setting the GO bit to flush out all updates.
387 *
388 * Simple hardware or hardware with special requirements can commit and
389 * flush out all updates for all planes from this hook and forgo all the
390 * other commit hooks for plane updates.
391 *
392 * This hook is called after any plane commit functions are called.
393 *
394 * Note that the power state of the display pipe when this function is
395 * called depends upon the exact helpers and calling sequence the driver
396 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
397 * the tradeoffs and variants of plane commit helpers.
398 *
399 * This callback is used by the atomic modeset helpers, but it is
400 * optional.
401 */
402 void (*atomic_flush)(struct drm_crtc *crtc,
403 struct drm_atomic_state *state);
404
405 /**
406 * @atomic_enable:
407 *
408 * This callback should be used to enable the CRTC. With the atomic
409 * drivers it is called before all encoders connected to this CRTC are
410 * enabled through the encoder's own &drm_encoder_helper_funcs.enable
411 * hook. If that sequence is too simple drivers can just add their own
412 * hooks and call it from this CRTC callback here by looping over all
413 * encoders connected to it using for_each_encoder_on_crtc().
414 *
415 * This hook is used only by atomic helpers, for symmetry with
416 * @atomic_disable. Atomic drivers don't need to implement it if there's
417 * no need to enable anything at the CRTC level. To ensure that runtime
418 * PM handling (using either DPMS or the new "ACTIVE" property) works
419 * @atomic_enable must be the inverse of @atomic_disable for atomic
420 * drivers.
421 *
422 * This function is optional.
423 */
424 void (*atomic_enable)(struct drm_crtc *crtc,
425 struct drm_atomic_state *state);
426
427 /**
428 * @atomic_disable:
429 *
430 * This callback should be used to disable the CRTC. With the atomic
431 * drivers it is called after all encoders connected to this CRTC have
432 * been shut off already using their own
433 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
434 * simple drivers can just add their own hooks and call it from this
435 * CRTC callback here by looping over all encoders connected to it using
436 * for_each_encoder_on_crtc().
437 *
438 * This hook is used only by atomic helpers. Atomic drivers don't
439 * need to implement it if there's no need to disable anything at the
440 * CRTC level.
441 *
442 * This function is optional.
443 */
444 void (*atomic_disable)(struct drm_crtc *crtc,
445 struct drm_atomic_state *state);
446
447 /**
448 * @get_scanout_position:
449 *
450 * Called by vblank timestamping code.
451 *
452 * Returns the current display scanout position from a CRTC and an
453 * optional accurate ktime_get() timestamp of when the position was
454 * measured. Note that this is a helper callback which is only used
455 * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp()
456 * for the @drm_crtc_funcs.get_vblank_timestamp callback.
457 *
458 * Parameters:
459 *
460 * crtc:
461 * The CRTC.
462 * in_vblank_irq:
463 * True when called from drm_crtc_handle_vblank(). Some drivers
464 * need to apply some workarounds for gpu-specific vblank irq
465 * quirks if the flag is set.
466 * vpos:
467 * Target location for current vertical scanout position.
468 * hpos:
469 * Target location for current horizontal scanout position.
470 * stime:
471 * Target location for timestamp taken immediately before
472 * scanout position query. Can be NULL to skip timestamp.
473 * etime:
474 * Target location for timestamp taken immediately after
475 * scanout position query. Can be NULL to skip timestamp.
476 * mode:
477 * Current display timings.
478 *
479 * Returns vpos as a positive number while in active scanout area.
480 * Returns vpos as a negative number inside vblank, counting the number
481 * of scanlines to go until end of vblank, e.g., -1 means "one scanline
482 * until start of active scanout / end of vblank."
483 *
484 * Returns:
485 *
486 * True on success, false if a reliable scanout position counter could
487 * not be read out.
488 */
489 bool (*get_scanout_position)(struct drm_crtc *crtc,
490 bool in_vblank_irq, int *vpos, int *hpos,
491 ktime_t *stime, ktime_t *etime,
492 const struct drm_display_mode *mode);
493 };
494
495 /**
496 * drm_crtc_helper_add - sets the helper vtable for a crtc
497 * @crtc: DRM CRTC
498 * @funcs: helper vtable to set for @crtc
499 */
500 static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
501 const struct drm_crtc_helper_funcs *funcs)
502 {
503 crtc->helper_private = funcs;
504 }
505
506 /**
507 * struct drm_encoder_helper_funcs - helper operations for encoders
508 *
509 * These hooks are used by the legacy CRTC helpers and the new atomic
510 * modesetting helpers.
511 */
512 struct drm_encoder_helper_funcs {
513 /**
514 * @dpms:
515 *
516 * Callback to control power levels on the encoder. If the mode passed in
517 * is unsupported, the provider must use the next lowest power level.
518 * This is used by the legacy encoder helpers to implement DPMS
519 * functionality in drm_helper_connector_dpms().
520 *
521 * This callback is also used to disable an encoder by calling it with
522 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
523 *
524 * This callback is used by the legacy CRTC helpers. Atomic helpers
525 * also support using this hook for enabling and disabling an encoder to
526 * facilitate transitions to atomic, but it is deprecated. Instead
527 * @enable and @disable should be used.
528 */
529 void (*dpms)(struct drm_encoder *encoder, int mode);
530
531 /**
532 * @mode_valid:
533 *
534 * This callback is used to check if a specific mode is valid in this
535 * encoder. This should be implemented if the encoder has some sort
536 * of restriction in the modes it can display. For example, a given
537 * encoder may be responsible to set a clock value. If the clock can
538 * not produce all the values for the available modes then this callback
539 * can be used to restrict the number of modes to only the ones that
540 * can be displayed.
541 *
542 * This hook is used by the probe helpers to filter the mode list in
543 * drm_helper_probe_single_connector_modes(), and it is used by the
544 * atomic helpers to validate modes supplied by userspace in
545 * drm_atomic_helper_check_modeset().
546 *
547 * This function is optional.
548 *
549 * NOTE:
550 *
551 * Since this function is both called from the check phase of an atomic
552 * commit, and the mode validation in the probe paths it is not allowed
553 * to look at anything else but the passed-in mode, and validate it
554 * against configuration-invariant hardware constraints. Any further
555 * limits which depend upon the configuration can only be checked in
556 * @mode_fixup or @atomic_check.
557 *
558 * RETURNS:
559 *
560 * drm_mode_status Enum
561 */
562 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
563 const struct drm_display_mode *mode);
564
565 /**
566 * @mode_fixup:
567 *
568 * This callback is used to validate and adjust a mode. The parameter
569 * mode is the display mode that should be fed to the next element in
570 * the display chain, either the final &drm_connector or a &drm_bridge.
571 * The parameter adjusted_mode is the input mode the encoder requires. It
572 * can be modified by this callback and does not need to match mode. See
573 * also &drm_crtc_state.adjusted_mode for more details.
574 *
575 * This function is used by both legacy CRTC helpers and atomic helpers.
576 * This hook is optional.
577 *
578 * NOTE:
579 *
580 * This function is called in the check phase of atomic modesets, which
581 * can be aborted for any reason (including on userspace's request to
582 * just check whether a configuration would be possible). Atomic drivers
583 * MUST NOT touch any persistent state (hardware or software) or data
584 * structures except the passed in adjusted_mode parameter.
585 *
586 * This is in contrast to the legacy CRTC helpers where this was
587 * allowed.
588 *
589 * Atomic drivers which need to inspect and adjust more state should
590 * instead use the @atomic_check callback. If @atomic_check is used,
591 * this hook isn't called since @atomic_check allows a strict superset
592 * of the functionality of @mode_fixup.
593 *
594 * Also beware that userspace can request its own custom modes, neither
595 * core nor helpers filter modes to the list of probe modes reported by
596 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
597 * that modes are filtered consistently put any encoder constraints and
598 * limits checks into @mode_valid.
599 *
600 * RETURNS:
601 *
602 * True if an acceptable configuration is possible, false if the modeset
603 * operation should be rejected.
604 */
605 bool (*mode_fixup)(struct drm_encoder *encoder,
606 const struct drm_display_mode *mode,
607 struct drm_display_mode *adjusted_mode);
608
609 /**
610 * @prepare:
611 *
612 * This callback should prepare the encoder for a subsequent modeset,
613 * which in practice means the driver should disable the encoder if it
614 * is running. Most drivers ended up implementing this by calling their
615 * @dpms hook with DRM_MODE_DPMS_OFF.
616 *
617 * This callback is used by the legacy CRTC helpers. Atomic helpers
618 * also support using this hook for disabling an encoder to facilitate
619 * transitions to atomic, but it is deprecated. Instead @disable should
620 * be used.
621 */
622 void (*prepare)(struct drm_encoder *encoder);
623
624 /**
625 * @commit:
626 *
627 * This callback should commit the new mode on the encoder after a modeset,
628 * which in practice means the driver should enable the encoder. Most
629 * drivers ended up implementing this by calling their @dpms hook with
630 * DRM_MODE_DPMS_ON.
631 *
632 * This callback is used by the legacy CRTC helpers. Atomic helpers
633 * also support using this hook for enabling an encoder to facilitate
634 * transitions to atomic, but it is deprecated. Instead @enable should
635 * be used.
636 */
637 void (*commit)(struct drm_encoder *encoder);
638
639 /**
640 * @mode_set:
641 *
642 * This callback is used to update the display mode of an encoder.
643 *
644 * Note that the display pipe is completely off when this function is
645 * called. Drivers which need hardware to be running before they program
646 * the new display mode (because they implement runtime PM) should not
647 * use this hook, because the helper library calls it only once and not
648 * every time the display pipeline is suspend using either DPMS or the
649 * new "ACTIVE" property. Such drivers should instead move all their
650 * encoder setup into the @enable callback.
651 *
652 * This callback is used both by the legacy CRTC helpers and the atomic
653 * modeset helpers. It is optional in the atomic helpers.
654 *
655 * NOTE:
656 *
657 * If the driver uses the atomic modeset helpers and needs to inspect
658 * the connector state or connector display info during mode setting,
659 * @atomic_mode_set can be used instead.
660 */
661 void (*mode_set)(struct drm_encoder *encoder,
662 struct drm_display_mode *mode,
663 struct drm_display_mode *adjusted_mode);
664
665 /**
666 * @atomic_mode_set:
667 *
668 * This callback is used to update the display mode of an encoder.
669 *
670 * Note that the display pipe is completely off when this function is
671 * called. Drivers which need hardware to be running before they program
672 * the new display mode (because they implement runtime PM) should not
673 * use this hook, because the helper library calls it only once and not
674 * every time the display pipeline is suspended using either DPMS or the
675 * new "ACTIVE" property. Such drivers should instead move all their
676 * encoder setup into the @enable callback.
677 *
678 * This callback is used by the atomic modeset helpers in place of the
679 * @mode_set callback, if set by the driver. It is optional and should
680 * be used instead of @mode_set if the driver needs to inspect the
681 * connector state or display info, since there is no direct way to
682 * go from the encoder to the current connector.
683 */
684 void (*atomic_mode_set)(struct drm_encoder *encoder,
685 struct drm_crtc_state *crtc_state,
686 struct drm_connector_state *conn_state);
687
688 /**
689 * @detect:
690 *
691 * This callback can be used by drivers who want to do detection on the
692 * encoder object instead of in connector functions.
693 *
694 * It is not used by any helper and therefore has purely driver-specific
695 * semantics. New drivers shouldn't use this and instead just implement
696 * their own private callbacks.
697 *
698 * FIXME:
699 *
700 * This should just be converted into a pile of driver vfuncs.
701 * Currently radeon, amdgpu and nouveau are using it.
702 */
703 enum drm_connector_status (*detect)(struct drm_encoder *encoder,
704 struct drm_connector *connector);
705
706 /**
707 * @atomic_disable:
708 *
709 * This callback should be used to disable the encoder. With the atomic
710 * drivers it is called before this encoder's CRTC has been shut off
711 * using their own &drm_crtc_helper_funcs.atomic_disable hook. If that
712 * sequence is too simple drivers can just add their own driver private
713 * encoder hooks and call them from CRTC's callback by looping over all
714 * encoders connected to it using for_each_encoder_on_crtc().
715 *
716 * This callback is a variant of @disable that provides the atomic state
717 * to the driver. If @atomic_disable is implemented, @disable is not
718 * called by the helpers.
719 *
720 * This hook is only used by atomic helpers. Atomic drivers don't need
721 * to implement it if there's no need to disable anything at the encoder
722 * level. To ensure that runtime PM handling (using either DPMS or the
723 * new "ACTIVE" property) works @atomic_disable must be the inverse of
724 * @atomic_enable.
725 */
726 void (*atomic_disable)(struct drm_encoder *encoder,
727 struct drm_atomic_state *state);
728
729 /**
730 * @atomic_enable:
731 *
732 * This callback should be used to enable the encoder. It is called
733 * after this encoder's CRTC has been enabled using their own
734 * &drm_crtc_helper_funcs.atomic_enable hook. If that sequence is
735 * too simple drivers can just add their own driver private encoder
736 * hooks and call them from CRTC's callback by looping over all encoders
737 * connected to it using for_each_encoder_on_crtc().
738 *
739 * This callback is a variant of @enable that provides the atomic state
740 * to the driver. If @atomic_enable is implemented, @enable is not
741 * called by the helpers.
742 *
743 * This hook is only used by atomic helpers, it is the opposite of
744 * @atomic_disable. Atomic drivers don't need to implement it if there's
745 * no need to enable anything at the encoder level. To ensure that
746 * runtime PM handling works @atomic_enable must be the inverse of
747 * @atomic_disable.
748 */
749 void (*atomic_enable)(struct drm_encoder *encoder,
750 struct drm_atomic_state *state);
751
752 /**
753 * @disable:
754 *
755 * This callback should be used to disable the encoder. With the atomic
756 * drivers it is called before this encoder's CRTC has been shut off
757 * using their own &drm_crtc_helper_funcs.disable hook. If that
758 * sequence is too simple drivers can just add their own driver private
759 * encoder hooks and call them from CRTC's callback by looping over all
760 * encoders connected to it using for_each_encoder_on_crtc().
761 *
762 * This hook is used both by legacy CRTC helpers and atomic helpers.
763 * Atomic drivers don't need to implement it if there's no need to
764 * disable anything at the encoder level. To ensure that runtime PM
765 * handling (using either DPMS or the new "ACTIVE" property) works
766 * @disable must be the inverse of @enable for atomic drivers.
767 *
768 * For atomic drivers also consider @atomic_disable and save yourself
769 * from having to read the NOTE below!
770 *
771 * NOTE:
772 *
773 * With legacy CRTC helpers there's a big semantic difference between
774 * @disable and other hooks (like @prepare or @dpms) used to shut down a
775 * encoder: @disable is only called when also logically disabling the
776 * display pipeline and needs to release any resources acquired in
777 * @mode_set (like shared PLLs, or again release pinned framebuffers).
778 *
779 * Therefore @disable must be the inverse of @mode_set plus @commit for
780 * drivers still using legacy CRTC helpers, which is different from the
781 * rules under atomic.
782 */
783 void (*disable)(struct drm_encoder *encoder);
784
785 /**
786 * @enable:
787 *
788 * This callback should be used to enable the encoder. With the atomic
789 * drivers it is called after this encoder's CRTC has been enabled using
790 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
791 * too simple drivers can just add their own driver private encoder
792 * hooks and call them from CRTC's callback by looping over all encoders
793 * connected to it using for_each_encoder_on_crtc().
794 *
795 * This hook is only used by atomic helpers, it is the opposite of
796 * @disable. Atomic drivers don't need to implement it if there's no
797 * need to enable anything at the encoder level. To ensure that
798 * runtime PM handling (using either DPMS or the new "ACTIVE" property)
799 * works @enable must be the inverse of @disable for atomic drivers.
800 */
801 void (*enable)(struct drm_encoder *encoder);
802
803 /**
804 * @atomic_check:
805 *
806 * This callback is used to validate encoder state for atomic drivers.
807 * Since the encoder is the object connecting the CRTC and connector it
808 * gets passed both states, to be able to validate interactions and
809 * update the CRTC to match what the encoder needs for the requested
810 * connector.
811 *
812 * Since this provides a strict superset of the functionality of
813 * @mode_fixup (the requested and adjusted modes are both available
814 * through the passed in &struct drm_crtc_state) @mode_fixup is not
815 * called when @atomic_check is implemented.
816 *
817 * This function is used by the atomic helpers, but it is optional.
818 *
819 * NOTE:
820 *
821 * This function is called in the check phase of an atomic update. The
822 * driver is not allowed to change anything outside of the free-standing
823 * state objects passed-in or assembled in the overall &drm_atomic_state
824 * update tracking structure.
825 *
826 * Also beware that userspace can request its own custom modes, neither
827 * core nor helpers filter modes to the list of probe modes reported by
828 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
829 * that modes are filtered consistently put any encoder constraints and
830 * limits checks into @mode_valid.
831 *
832 * RETURNS:
833 *
834 * 0 on success, -EINVAL if the state or the transition can't be
835 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
836 * attempt to obtain another state object ran into a &drm_modeset_lock
837 * deadlock.
838 */
839 int (*atomic_check)(struct drm_encoder *encoder,
840 struct drm_crtc_state *crtc_state,
841 struct drm_connector_state *conn_state);
842 };
843
844 /**
845 * drm_encoder_helper_add - sets the helper vtable for an encoder
846 * @encoder: DRM encoder
847 * @funcs: helper vtable to set for @encoder
848 */
849 static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
850 const struct drm_encoder_helper_funcs *funcs)
851 {
852 encoder->helper_private = funcs;
853 }
854
855 /**
856 * struct drm_connector_helper_funcs - helper operations for connectors
857 *
858 * These functions are used by the atomic and legacy modeset helpers and by the
859 * probe helpers.
860 */
861 struct drm_connector_helper_funcs {
862 /**
863 * @get_modes:
864 *
865 * This function should fill in all modes currently valid for the sink
866 * into the &drm_connector.probed_modes list. It should also update the
867 * EDID property by calling drm_connector_update_edid_property().
868 *
869 * The usual way to implement this is to cache the EDID retrieved in the
870 * probe callback somewhere in the driver-private connector structure.
871 * In this function drivers then parse the modes in the EDID and add
872 * them by calling drm_add_edid_modes(). But connectors that drive a
873 * fixed panel can also manually add specific modes using
874 * drm_mode_probed_add(). Drivers which manually add modes should also
875 * make sure that the &drm_connector.display_info,
876 * &drm_connector.width_mm and &drm_connector.height_mm fields are
877 * filled in.
878 *
879 * Note that the caller function will automatically add standard VESA
880 * DMT modes up to 1024x768 if the .get_modes() helper operation returns
881 * no mode and if the connector status is connector_status_connected or
882 * connector_status_unknown. There is no need to call
883 * drm_add_modes_noedid() manually in that case.
884 *
885 * Virtual drivers that just want some standard VESA mode with a given
886 * resolution can call drm_add_modes_noedid(), and mark the preferred
887 * one using drm_set_preferred_mode().
888 *
889 * This function is only called after the @detect hook has indicated
890 * that a sink is connected and when the EDID isn't overridden through
891 * sysfs or the kernel commandline.
892 *
893 * This callback is used by the probe helpers in e.g.
894 * drm_helper_probe_single_connector_modes().
895 *
896 * To avoid races with concurrent connector state updates, the helper
897 * libraries always call this with the &drm_mode_config.connection_mutex
898 * held. Because of this it's safe to inspect &drm_connector->state.
899 *
900 * RETURNS:
901 *
902 * The number of modes added by calling drm_mode_probed_add(). Return 0
903 * on failures (no modes) instead of negative error codes.
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
1058 * &drm_atomic_state update tracking structure passed in.
1059 *
1060 * RETURNS:
1061 *
1062 * Encoder that should be used for the given connector and connector
1063 * state, or NULL if no suitable encoder exists. Note that the helpers
1064 * will ensure that encoders aren't used twice, drivers should not check
1065 * for this.
1066 */
1067 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
1068 struct drm_atomic_state *state);
1069
1070 /**
1071 * @atomic_check:
1072 *
1073 * This hook is used to validate connector state. This function is
1074 * called from &drm_atomic_helper_check_modeset, and is called when
1075 * a connector property is set, or a modeset on the crtc is forced.
1076 *
1077 * Because &drm_atomic_helper_check_modeset may be called multiple times,
1078 * this function should handle being called multiple times as well.
1079 *
1080 * This function is also allowed to inspect any other object's state and
1081 * can add more state objects to the atomic commit if needed. Care must
1082 * be taken though to ensure that state check and compute functions for
1083 * these added states are all called, and derived state in other objects
1084 * all updated. Again the recommendation is to just call check helpers
1085 * until a maximal configuration is reached.
1086 *
1087 * NOTE:
1088 *
1089 * This function is called in the check phase of an atomic update. The
1090 * driver is not allowed to change anything outside of the free-standing
1091 * state objects passed-in or assembled in the overall &drm_atomic_state
1092 * update tracking structure.
1093 *
1094 * RETURNS:
1095 *
1096 * 0 on success, -EINVAL if the state or the transition can't be
1097 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1098 * attempt to obtain another state object ran into a &drm_modeset_lock
1099 * deadlock.
1100 */
1101 int (*atomic_check)(struct drm_connector *connector,
1102 struct drm_atomic_state *state);
1103
1104 /**
1105 * @atomic_commit:
1106 *
1107 * This hook is to be used by drivers implementing writeback connectors
1108 * that need a point when to commit the writeback job to the hardware.
1109 * The writeback_job to commit is available in the new connector state,
1110 * in &drm_connector_state.writeback_job.
1111 *
1112 * This hook is optional.
1113 *
1114 * This callback is used by the atomic modeset helpers.
1115 */
1116 void (*atomic_commit)(struct drm_connector *connector,
1117 struct drm_atomic_state *state);
1118
1119 /**
1120 * @prepare_writeback_job:
1121 *
1122 * As writeback jobs contain a framebuffer, drivers may need to
1123 * prepare and clean them up the same way they can prepare and
1124 * clean up framebuffers for planes. This optional connector operation
1125 * is used to support the preparation of writeback jobs. The job
1126 * prepare operation is called from drm_atomic_helper_prepare_planes()
1127 * for struct &drm_writeback_connector connectors only.
1128 *
1129 * This operation is optional.
1130 *
1131 * This callback is used by the atomic modeset helpers.
1132 */
1133 int (*prepare_writeback_job)(struct drm_writeback_connector *connector,
1134 struct drm_writeback_job *job);
1135 /**
1136 * @cleanup_writeback_job:
1137 *
1138 * This optional connector operation is used to support the
1139 * cleanup of writeback jobs. The job cleanup operation is called
1140 * from the existing drm_writeback_cleanup_job() function, invoked
1141 * both when destroying the job as part of an aborted commit, or when
1142 * the job completes.
1143 *
1144 * This operation is optional.
1145 *
1146 * This callback is used by the atomic modeset helpers.
1147 */
1148 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector,
1149 struct drm_writeback_job *job);
1150
1151 /**
1152 * @enable_hpd:
1153 *
1154 * Enable hot-plug detection for the connector.
1155 *
1156 * This operation is optional.
1157 *
1158 * This callback is used by the drm_kms_helper_poll_enable() helpers.
1159 *
1160 * This operation does not need to perform any hpd state tracking as
1161 * the DRM core handles that maintenance and ensures the calls to enable
1162 * and disable hpd are balanced.
1163 *
1164 */
1165 void (*enable_hpd)(struct drm_connector *connector);
1166
1167 /**
1168 * @disable_hpd:
1169 *
1170 * Disable hot-plug detection for the connector.
1171 *
1172 * This operation is optional.
1173 *
1174 * This callback is used by the drm_kms_helper_poll_disable() helpers.
1175 *
1176 * This operation does not need to perform any hpd state tracking as
1177 * the DRM core handles that maintenance and ensures the calls to enable
1178 * and disable hpd are balanced.
1179 *
1180 */
1181 void (*disable_hpd)(struct drm_connector *connector);
1182 };
1183
1184 /**
1185 * drm_connector_helper_add - sets the helper vtable for a connector
1186 * @connector: DRM connector
1187 * @funcs: helper vtable to set for @connector
1188 */
1189 static inline void drm_connector_helper_add(struct drm_connector *connector,
1190 const struct drm_connector_helper_funcs *funcs)
1191 {
1192 connector->helper_private = funcs;
1193 }
1194
1195 /**
1196 * struct drm_plane_helper_funcs - helper operations for planes
1197 *
1198 * These functions are used by the atomic helpers.
1199 */
1200 struct drm_plane_helper_funcs {
1201 /**
1202 * @prepare_fb:
1203 *
1204 * This hook is to prepare a framebuffer for scanout by e.g. pinning
1205 * its backing storage or relocating it into a contiguous block of
1206 * VRAM. Other possible preparatory work includes flushing caches.
1207 *
1208 * This function must not block for outstanding rendering, since it is
1209 * called in the context of the atomic IOCTL even for async commits to
1210 * be able to return any errors to userspace. Instead the recommended
1211 * way is to fill out the &drm_plane_state.fence of the passed-in
1212 * &drm_plane_state. If the driver doesn't support native fences then
1213 * equivalent functionality should be implemented through private
1214 * members in the plane structure.
1215 *
1216 * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook
1217 * set drm_gem_plane_helper_prepare_fb() is called automatically to
1218 * implement this. Other drivers which need additional plane processing
1219 * can call drm_gem_plane_helper_prepare_fb() from their @prepare_fb
1220 * hook.
1221 *
1222 * The resources acquired in @prepare_fb persist after the end of
1223 * the atomic commit. Resources that can be release at the commit's end
1224 * should be acquired in @begin_fb_access and released in @end_fb_access.
1225 * For example, a GEM buffer's pin operation belongs into @prepare_fb to
1226 * keep the buffer pinned after the commit. But a vmap operation for
1227 * shadow-plane helpers belongs into @begin_fb_access, so that atomic
1228 * helpers remove the mapping at the end of the commit.
1229 *
1230 * The helpers will call @cleanup_fb with matching arguments for every
1231 * successful call to this hook.
1232 *
1233 * This callback is used by the atomic modeset helpers, but it is
1234 * optional. See @begin_fb_access for preparing per-commit resources.
1235 *
1236 * RETURNS:
1237 *
1238 * 0 on success or one of the following negative error codes allowed by
1239 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
1240 * this callback is the only one which can fail an atomic commit,
1241 * everything else must complete successfully.
1242 */
1243 int (*prepare_fb)(struct drm_plane *plane,
1244 struct drm_plane_state *new_state);
1245 /**
1246 * @cleanup_fb:
1247 *
1248 * This hook is called to clean up any resources allocated for the given
1249 * framebuffer and plane configuration in @prepare_fb.
1250 *
1251 * This callback is used by the atomic modeset helpers, but it is
1252 * optional.
1253 */
1254 void (*cleanup_fb)(struct drm_plane *plane,
1255 struct drm_plane_state *old_state);
1256
1257 /**
1258 * @begin_fb_access:
1259 *
1260 * This hook prepares the plane for access during an atomic commit.
1261 * In contrast to @prepare_fb, resources acquired in @begin_fb_access,
1262 * are released at the end of the atomic commit in @end_fb_access.
1263 *
1264 * For example, with shadow-plane helpers, the GEM buffer's vmap
1265 * operation belongs into @begin_fb_access, so that the buffer's
1266 * memory will be unmapped at the end of the commit in @end_fb_access.
1267 * But a GEM buffer's pin operation belongs into @prepare_fb
1268 * to keep the buffer pinned after the commit.
1269 *
1270 * The callback is used by the atomic modeset helpers, but it is optional.
1271 * See @end_fb_cleanup for undoing the effects of @begin_fb_access and
1272 * @prepare_fb for acquiring resources until the next pageflip.
1273 *
1274 * Returns:
1275 * 0 on success, or a negative errno code otherwise.
1276 */
1277 int (*begin_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
1278
1279 /**
1280 * @end_fb_access:
1281 *
1282 * This hook cleans up resources allocated by @begin_fb_access. It it called
1283 * at the end of a commit for the new plane state.
1284 */
1285 void (*end_fb_access)(struct drm_plane *plane, struct drm_plane_state *new_plane_state);
1286
1287 /**
1288 * @atomic_check:
1289 *
1290 * Drivers should check plane specific constraints in this hook.
1291 *
1292 * When using drm_atomic_helper_check_planes() plane's @atomic_check
1293 * hooks are called before the ones for CRTCs, which allows drivers to
1294 * request shared resources that the CRTC controls here. For more
1295 * complicated dependencies the driver can call the provided check helpers
1296 * multiple times until the computed state has a final configuration and
1297 * everything has been checked.
1298 *
1299 * This function is also allowed to inspect any other object's state and
1300 * can add more state objects to the atomic commit if needed. Care must
1301 * be taken though to ensure that state check and compute functions for
1302 * these added states are all called, and derived state in other objects
1303 * all updated. Again the recommendation is to just call check helpers
1304 * until a maximal configuration is reached.
1305 *
1306 * This callback is used by the atomic modeset helpers, but it is
1307 * optional.
1308 *
1309 * NOTE:
1310 *
1311 * This function is called in the check phase of an atomic update. The
1312 * driver is not allowed to change anything outside of the
1313 * &drm_atomic_state update tracking structure.
1314 *
1315 * RETURNS:
1316 *
1317 * 0 on success, -EINVAL if the state or the transition can't be
1318 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1319 * attempt to obtain another state object ran into a &drm_modeset_lock
1320 * deadlock.
1321 */
1322 int (*atomic_check)(struct drm_plane *plane,
1323 struct drm_atomic_state *state);
1324
1325 /**
1326 * @atomic_update:
1327 *
1328 * Drivers should use this function to update the plane state. This
1329 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
1330 * drm_crtc_helper_funcs.atomic_flush callbacks.
1331 *
1332 * Note that the power state of the display pipe when this function is
1333 * called depends upon the exact helpers and calling sequence the driver
1334 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1335 * the tradeoffs and variants of plane commit helpers.
1336 *
1337 * This callback is used by the atomic modeset helpers, but it is optional.
1338 */
1339 void (*atomic_update)(struct drm_plane *plane,
1340 struct drm_atomic_state *state);
1341
1342 /**
1343 * @atomic_enable:
1344 *
1345 * Drivers should use this function to unconditionally enable a plane.
1346 * This hook is called in-between the &drm_crtc_helper_funcs.atomic_begin
1347 * and drm_crtc_helper_funcs.atomic_flush callbacks. It is called after
1348 * @atomic_update, which will be called for all enabled planes. Drivers
1349 * that use @atomic_enable should set up a plane in @atomic_update and
1350 * afterwards enable the plane in @atomic_enable. If a plane needs to be
1351 * enabled before installing the scanout buffer, drivers can still do
1352 * so in @atomic_update.
1353 *
1354 * Note that the power state of the display pipe when this function is
1355 * called depends upon the exact helpers and calling sequence the driver
1356 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1357 * the tradeoffs and variants of plane commit helpers.
1358 *
1359 * This callback is used by the atomic modeset helpers, but it is
1360 * optional. If implemented, @atomic_enable should be the inverse of
1361 * @atomic_disable. Drivers that don't want to use either can still
1362 * implement the complete plane update in @atomic_update.
1363 */
1364 void (*atomic_enable)(struct drm_plane *plane,
1365 struct drm_atomic_state *state);
1366
1367 /**
1368 * @atomic_disable:
1369 *
1370 * Drivers should use this function to unconditionally disable a plane.
1371 * This hook is called in-between the
1372 * &drm_crtc_helper_funcs.atomic_begin and
1373 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
1374 * @atomic_update, which will be called for disabling planes, too, if
1375 * the @atomic_disable hook isn't implemented.
1376 *
1377 * This hook is also useful to disable planes in preparation of a modeset,
1378 * by calling drm_atomic_helper_disable_planes_on_crtc() from the
1379 * &drm_crtc_helper_funcs.disable hook.
1380 *
1381 * Note that the power state of the display pipe when this function is
1382 * called depends upon the exact helpers and calling sequence the driver
1383 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1384 * the tradeoffs and variants of plane commit helpers.
1385 *
1386 * This callback is used by the atomic modeset helpers, but it is
1387 * optional. It's intended to reverse the effects of @atomic_enable.
1388 */
1389 void (*atomic_disable)(struct drm_plane *plane,
1390 struct drm_atomic_state *state);
1391
1392 /**
1393 * @atomic_async_check:
1394 *
1395 * Drivers should set this function pointer to check if the plane's
1396 * atomic state can be updated in a async fashion. Here async means
1397 * "not vblank synchronized".
1398 *
1399 * This hook is called by drm_atomic_async_check() to establish if a
1400 * given update can be committed asynchronously, that is, if it can
1401 * jump ahead of the state currently queued for update.
1402 *
1403 * RETURNS:
1404 *
1405 * Return 0 on success and any error returned indicates that the update
1406 * can not be applied in asynchronous manner.
1407 */
1408 int (*atomic_async_check)(struct drm_plane *plane,
1409 struct drm_atomic_state *state);
1410
1411 /**
1412 * @atomic_async_update:
1413 *
1414 * Drivers should set this function pointer to perform asynchronous
1415 * updates of planes, that is, jump ahead of the currently queued
1416 * state and update the plane. Here async means "not vblank
1417 * synchronized".
1418 *
1419 * This hook is called by drm_atomic_helper_async_commit().
1420 *
1421 * An async update will happen on legacy cursor updates. An async
1422 * update won't happen if there is an outstanding commit modifying
1423 * the same plane.
1424 *
1425 * When doing async_update drivers shouldn't replace the
1426 * &drm_plane_state but update the current one with the new plane
1427 * configurations in the new plane_state.
1428 *
1429 * Drivers should also swap the framebuffers between current plane
1430 * state (&drm_plane.state) and new_state.
1431 * This is required since cleanup for async commits is performed on
1432 * the new state, rather than old state like for traditional commits.
1433 * Since we want to give up the reference on the current (old) fb
1434 * instead of our brand new one, swap them in the driver during the
1435 * async commit.
1436 *
1437 * FIXME:
1438 * - It only works for single plane updates
1439 * - Async Pageflips are not supported yet
1440 * - Some hw might still scan out the old buffer until the next
1441 * vblank, however we let go of the fb references as soon as
1442 * we run this hook. For now drivers must implement their own workers
1443 * for deferring if needed, until a common solution is created.
1444 */
1445 void (*atomic_async_update)(struct drm_plane *plane,
1446 struct drm_atomic_state *state);
1447
1448 /**
1449 * @get_scanout_buffer:
1450 *
1451 * Get the current scanout buffer, to display a message with drm_panic.
1452 * The driver should do the minimum changes to provide a buffer,
1453 * that can be used to display the panic screen. Currently only linear
1454 * buffers are supported. Non-linear buffer support is on the TODO list.
1455 * The device &dev.mode_config.panic_lock is taken before calling this
1456 * function, so you can safely access the &plane.state
1457 * It is called from a panic callback, and must follow its restrictions.
1458 * Please look the documentation at drm_panic_trylock() for an in-depth
1459 * discussions of what's safe and what is not allowed.
1460 * It's a best effort mode, so it's expected that in some complex cases
1461 * the panic screen won't be displayed.
1462 * The returned &drm_scanout_buffer.map must be valid if no error code is
1463 * returned.
1464 *
1465 * Return:
1466 * %0 on success, negative errno on failure.
1467 */
1468 int (*get_scanout_buffer)(struct drm_plane *plane,
1469 struct drm_scanout_buffer *sb);
1470
1471 /**
1472 * @panic_flush:
1473 *
1474 * It is used by drm_panic, and is called after the panic screen is
1475 * drawn to the scanout buffer. In this function, the driver
1476 * can send additional commands to the hardware, to make the scanout
1477 * buffer visible.
1478 * It is only called if get_scanout_buffer() returned successfully, and
1479 * the &dev.mode_config.panic_lock is held during the entire sequence.
1480 * It is called from a panic callback, and must follow its restrictions.
1481 * Please look the documentation at drm_panic_trylock() for an in-depth
1482 * discussions of what's safe and what is not allowed.
1483 */
1484 void (*panic_flush)(struct drm_plane *plane);
1485 };
1486
1487 /**
1488 * drm_plane_helper_add - sets the helper vtable for a plane
1489 * @plane: DRM plane
1490 * @funcs: helper vtable to set for @plane
1491 */
1492 static inline void drm_plane_helper_add(struct drm_plane *plane,
1493 const struct drm_plane_helper_funcs *funcs)
1494 {
1495 plane->helper_private = funcs;
1496 }
1497
1498 /**
1499 * struct drm_mode_config_helper_funcs - global modeset helper operations
1500 *
1501 * These helper functions are used by the atomic helpers.
1502 */
1503 struct drm_mode_config_helper_funcs {
1504 /**
1505 * @atomic_commit_tail:
1506 *
1507 * This hook is used by the default atomic_commit() hook implemented in
1508 * drm_atomic_helper_commit() together with the nonblocking commit
1509 * helpers (see drm_atomic_helper_setup_commit() for a starting point)
1510 * to implement blocking and nonblocking commits easily. It is not used
1511 * by the atomic helpers
1512 *
1513 * This function is called when the new atomic state has already been
1514 * swapped into the various state pointers. The passed in state
1515 * therefore contains copies of the old/previous state. This hook should
1516 * commit the new state into hardware. Note that the helpers have
1517 * already waited for preceding atomic commits and fences, but drivers
1518 * can add more waiting calls at the start of their implementation, e.g.
1519 * to wait for driver-internal request for implicit syncing, before
1520 * starting to commit the update to the hardware.
1521 *
1522 * After the atomic update is committed to the hardware this hook needs
1523 * to call drm_atomic_helper_commit_hw_done(). Then wait for the update
1524 * to be executed by the hardware, for example using
1525 * drm_atomic_helper_wait_for_vblanks() or
1526 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
1527 * framebuffers using drm_atomic_helper_cleanup_planes().
1528 *
1529 * When disabling a CRTC this hook _must_ stall for the commit to
1530 * complete. Vblank waits don't work on disabled CRTC, hence the core
1531 * can't take care of this. And it also can't rely on the vblank event,
1532 * since that can be signalled already when the screen shows black,
1533 * which can happen much earlier than the last hardware access needed to
1534 * shut off the display pipeline completely.
1535 *
1536 * This hook is optional, the default implementation is
1537 * drm_atomic_helper_commit_tail().
1538 */
1539 void (*atomic_commit_tail)(struct drm_atomic_state *state);
1540
1541 /**
1542 * @atomic_commit_setup:
1543 *
1544 * This hook is used by the default atomic_commit() hook implemented in
1545 * drm_atomic_helper_commit() together with the nonblocking helpers (see
1546 * drm_atomic_helper_setup_commit()) to extend the DRM commit setup. It
1547 * is not used by the atomic helpers.
1548 *
1549 * This function is called at the end of
1550 * drm_atomic_helper_setup_commit(), so once the commit has been
1551 * properly setup across the generic DRM object states. It allows
1552 * drivers to do some additional commit tracking that isn't related to a
1553 * CRTC, plane or connector, tracked in a &drm_private_obj structure.
1554 *
1555 * Note that the documentation of &drm_private_obj has more details on
1556 * how one should implement this.
1557 *
1558 * This hook is optional.
1559 */
1560 int (*atomic_commit_setup)(struct drm_atomic_state *state);
1561 };
1562
1563 #endif
1564
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