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;
52
53/**
54 * struct drm_crtc_helper_funcs - helper operations for CRTCs
55 *
56 * These hooks are used by the legacy CRTC helpers, the transitional plane
57 * helpers and the new atomic modesetting helpers.
58 */
59struct drm_crtc_helper_funcs {
60 /**
61 * @dpms:
62 *
63 * Callback to control power levels on the CRTC. If the mode passed in
64 * is unsupported, the provider must use the next lowest power level.
65 * This is used by the legacy CRTC helpers to implement DPMS
66 * functionality in drm_helper_connector_dpms().
67 *
68 * This callback is also used to disable a CRTC by calling it with
69 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
70 *
71 * This callback is used by the legacy CRTC helpers. Atomic helpers
72 * also support using this hook for enabling and disabling a CRTC to
73 * facilitate transitions to atomic, but it is deprecated. Instead
74 * @atomic_enable and @atomic_disable should be used.
75 */
76 void (*dpms)(struct drm_crtc *crtc, int mode);
77
78 /**
79 * @prepare:
80 *
81 * This callback should prepare the CRTC for a subsequent modeset, which
82 * in practice means the driver should disable the CRTC if it is
83 * running. Most drivers ended up implementing this by calling their
84 * @dpms hook with DRM_MODE_DPMS_OFF.
85 *
86 * This callback is used by the legacy CRTC helpers. Atomic helpers
87 * also support using this hook for disabling a CRTC to facilitate
88 * transitions to atomic, but it is deprecated. Instead @atomic_disable
89 * should be used.
90 */
91 void (*prepare)(struct drm_crtc *crtc);
92
93 /**
94 * @commit:
95 *
96 * This callback should commit the new mode on the CRTC after a modeset,
97 * which in practice means the driver should enable the CRTC. Most
98 * drivers ended up implementing this by calling their @dpms hook with
99 * DRM_MODE_DPMS_ON.
100 *
101 * This callback is used by the legacy CRTC helpers. Atomic helpers
102 * also support using this hook for enabling a CRTC to facilitate
103 * transitions to atomic, but it is deprecated. Instead @atomic_enable
104 * should be used.
105 */
106 void (*commit)(struct drm_crtc *crtc);
107
108 /**
109 * @mode_valid:
110 *
111 * This callback is used to check if a specific mode is valid in this
112 * crtc. This should be implemented if the crtc has some sort of
113 * restriction in the modes it can display. For example, a given crtc
114 * may be responsible to set a clock value. If the clock can not
115 * produce all the values for the available modes then this callback
116 * can be used to restrict the number of modes to only the ones that
117 * can be displayed.
118 *
119 * This hook is used by the probe helpers to filter the mode list in
120 * drm_helper_probe_single_connector_modes(), and it is used by the
121 * atomic helpers to validate modes supplied by userspace in
122 * drm_atomic_helper_check_modeset().
123 *
124 * This function is optional.
125 *
126 * NOTE:
127 *
128 * Since this function is both called from the check phase of an atomic
129 * commit, and the mode validation in the probe paths it is not allowed
130 * to look at anything else but the passed-in mode, and validate it
131 * against configuration-invariant hardward constraints. Any further
132 * limits which depend upon the configuration can only be checked in
133 * @mode_fixup or @atomic_check.
134 *
135 * RETURNS:
136 *
137 * drm_mode_status Enum
138 */
139 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc,
140 const struct drm_display_mode *mode);
141
142 /**
143 * @mode_fixup:
144 *
145 * This callback is used to validate a mode. The parameter mode is the
146 * display mode that userspace requested, adjusted_mode is the mode the
147 * encoders need to be fed with. Note that this is the inverse semantics
148 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
149 * vfunc. If the CRTC cannot support the requested conversion from mode
150 * to adjusted_mode it should reject the modeset. See also
151 * &drm_crtc_state.adjusted_mode for more details.
152 *
153 * This function is used by both legacy CRTC helpers and atomic helpers.
154 * With atomic helpers it is optional.
155 *
156 * NOTE:
157 *
158 * This function is called in the check phase of atomic modesets, which
159 * can be aborted for any reason (including on userspace's request to
160 * just check whether a configuration would be possible). Atomic drivers
161 * MUST NOT touch any persistent state (hardware or software) or data
162 * structures except the passed in adjusted_mode parameter.
163 *
164 * This is in contrast to the legacy CRTC helpers where this was
165 * allowed.
166 *
167 * Atomic drivers which need to inspect and adjust more state should
168 * instead use the @atomic_check callback, but note that they're not
169 * perfectly equivalent: @mode_valid is called from
170 * drm_atomic_helper_check_modeset(), but @atomic_check is called from
171 * drm_atomic_helper_check_planes(), because originally it was meant for
172 * plane update checks only.
173 *
174 * Also beware that userspace can request its own custom modes, neither
175 * core nor helpers filter modes to the list of probe modes reported by
176 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
177 * that modes are filtered consistently put any CRTC constraints and
178 * limits checks into @mode_valid.
179 *
180 * RETURNS:
181 *
182 * True if an acceptable configuration is possible, false if the modeset
183 * operation should be rejected.
184 */
185 bool (*mode_fixup)(struct drm_crtc *crtc,
186 const struct drm_display_mode *mode,
187 struct drm_display_mode *adjusted_mode);
188
189 /**
190 * @mode_set:
191 *
192 * This callback is used by the legacy CRTC helpers to set a new mode,
193 * position and framebuffer. Since it ties the primary plane to every
194 * mode change it is incompatible with universal plane support. And
195 * since it can't update other planes it's incompatible with atomic
196 * modeset support.
197 *
198 * This callback is only used by CRTC helpers and deprecated.
199 *
200 * RETURNS:
201 *
202 * 0 on success or a negative error code on failure.
203 */
204 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode,
205 struct drm_display_mode *adjusted_mode, int x, int y,
206 struct drm_framebuffer *old_fb);
207
208 /**
209 * @mode_set_nofb:
210 *
211 * This callback is used to update the display mode of a CRTC without
212 * changing anything of the primary plane configuration. This fits the
213 * requirement of atomic and hence is used by the atomic helpers. It is
214 * also used by the transitional plane helpers to implement a
215 * @mode_set hook in drm_helper_crtc_mode_set().
216 *
217 * Note that the display pipe is completely off when this function is
218 * called. Atomic drivers which need hardware to be running before they
219 * program the new display mode (e.g. because they implement runtime PM)
220 * should not use this hook. This is because the helper library calls
221 * this hook only once per mode change and not every time the display
222 * pipeline is suspended using either DPMS or the new "ACTIVE" property.
223 * Which means register values set in this callback might get reset when
224 * the CRTC is suspended, but not restored. Such drivers should instead
225 * move all their CRTC setup into the @atomic_enable callback.
226 *
227 * This callback is optional.
228 */
229 void (*mode_set_nofb)(struct drm_crtc *crtc);
230
231 /**
232 * @mode_set_base:
233 *
234 * This callback is used by the legacy CRTC helpers to set a new
235 * framebuffer and scanout position. It is optional and used as an
236 * optimized fast-path instead of a full mode set operation with all the
237 * resulting flickering. If it is not present
238 * drm_crtc_helper_set_config() will fall back to a full modeset, using
239 * the @mode_set callback. Since it can't update other planes it's
240 * incompatible with atomic modeset support.
241 *
242 * This callback is only used by the CRTC helpers and deprecated.
243 *
244 * RETURNS:
245 *
246 * 0 on success or a negative error code on failure.
247 */
248 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y,
249 struct drm_framebuffer *old_fb);
250
251 /**
252 * @mode_set_base_atomic:
253 *
254 * This callback is used by the fbdev helpers to set a new framebuffer
255 * and scanout without sleeping, i.e. from an atomic calling context. It
256 * is only used to implement kgdb support.
257 *
258 * This callback is optional and only needed for kgdb support in the fbdev
259 * helpers.
260 *
261 * RETURNS:
262 *
263 * 0 on success or a negative error code on failure.
264 */
265 int (*mode_set_base_atomic)(struct drm_crtc *crtc,
266 struct drm_framebuffer *fb, int x, int y,
267 enum mode_set_atomic);
268
269 /**
270 * @disable:
271 *
272 * This callback should be used to disable the CRTC. With the atomic
273 * drivers it is called after all encoders connected to this CRTC have
274 * been shut off already using their own
275 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
276 * simple drivers can just add their own hooks and call it from this
277 * CRTC callback here by looping over all encoders connected to it using
278 * for_each_encoder_on_crtc().
279 *
280 * This hook is used both by legacy CRTC helpers and atomic helpers.
281 * Atomic drivers don't need to implement it if there's no need to
282 * disable anything at the CRTC level. To ensure that runtime PM
283 * handling (using either DPMS or the new "ACTIVE" property) works
284 * @disable must be the inverse of @atomic_enable for atomic drivers.
285 * Atomic drivers should consider to use @atomic_disable instead of
286 * this one.
287 *
288 * NOTE:
289 *
290 * With legacy CRTC helpers there's a big semantic difference between
291 * @disable and other hooks (like @prepare or @dpms) used to shut down a
292 * CRTC: @disable is only called when also logically disabling the
293 * display pipeline and needs to release any resources acquired in
294 * @mode_set (like shared PLLs, or again release pinned framebuffers).
295 *
296 * Therefore @disable must be the inverse of @mode_set plus @commit for
297 * drivers still using legacy CRTC helpers, which is different from the
298 * rules under atomic.
299 */
300 void (*disable)(struct drm_crtc *crtc);
301
302 /**
303 * @atomic_check:
304 *
305 * Drivers should check plane-update related CRTC constraints in this
306 * hook. They can also check mode related limitations but need to be
307 * aware of the calling order, since this hook is used by
308 * drm_atomic_helper_check_planes() whereas the preparations needed to
309 * check output routing and the display mode is done in
310 * drm_atomic_helper_check_modeset(). Therefore drivers that want to
311 * check output routing and display mode constraints in this callback
312 * must ensure that drm_atomic_helper_check_modeset() has been called
313 * beforehand. This is calling order used by the default helper
314 * implementation in drm_atomic_helper_check().
315 *
316 * When using drm_atomic_helper_check_planes() this hook is called
317 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which
318 * allows drivers to assign shared resources requested by planes in this
319 * callback here. For more complicated dependencies the driver can call
320 * the provided check helpers multiple times until the computed state
321 * has a final configuration and everything has been checked.
322 *
323 * This function is also allowed to inspect any other object's state and
324 * can add more state objects to the atomic commit if needed. Care must
325 * be taken though to ensure that state check and compute functions for
326 * these added states are all called, and derived state in other objects
327 * all updated. Again the recommendation is to just call check helpers
328 * until a maximal configuration is reached.
329 *
330 * This callback is used by the atomic modeset helpers and by the
331 * transitional plane helpers, but it is optional.
332 *
333 * NOTE:
334 *
335 * This function is called in the check phase of an atomic update. The
336 * driver is not allowed to change anything outside of the free-standing
337 * state objects passed-in or assembled in the overall &drm_atomic_state
338 * update tracking structure.
339 *
340 * Also beware that userspace can request its own custom modes, neither
341 * core nor helpers filter modes to the list of probe modes reported by
342 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
343 * that modes are filtered consistently put any CRTC constraints and
344 * limits checks into @mode_valid.
345 *
346 * RETURNS:
347 *
348 * 0 on success, -EINVAL if the state or the transition can't be
349 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
350 * attempt to obtain another state object ran into a &drm_modeset_lock
351 * deadlock.
352 */
353 int (*atomic_check)(struct drm_crtc *crtc,
354 struct drm_crtc_state *state);
355
356 /**
357 * @atomic_begin:
358 *
359 * Drivers should prepare for an atomic update of multiple planes on
360 * a CRTC in this hook. Depending upon hardware this might be vblank
361 * evasion, blocking updates by setting bits or doing preparatory work
362 * for e.g. manual update display.
363 *
364 * This hook is called before any plane commit functions are called.
365 *
366 * Note that the power state of the display pipe when this function is
367 * called depends upon the exact helpers and calling sequence the driver
368 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
369 * the tradeoffs and variants of plane commit helpers.
370 *
371 * This callback is used by the atomic modeset helpers and by the
372 * transitional plane helpers, but it is optional.
373 */
374 void (*atomic_begin)(struct drm_crtc *crtc,
375 struct drm_crtc_state *old_crtc_state);
376 /**
377 * @atomic_flush:
378 *
379 * Drivers should finalize an atomic update of multiple planes on
380 * a CRTC in this hook. Depending upon hardware this might include
381 * checking that vblank evasion was successful, unblocking updates by
382 * setting bits or setting the GO bit to flush out all updates.
383 *
384 * Simple hardware or hardware with special requirements can commit and
385 * flush out all updates for all planes from this hook and forgo all the
386 * other commit hooks for plane updates.
387 *
388 * This hook is called after any plane commit functions are called.
389 *
390 * Note that the power state of the display pipe when this function is
391 * called depends upon the exact helpers and calling sequence the driver
392 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
393 * the tradeoffs and variants of plane commit helpers.
394 *
395 * This callback is used by the atomic modeset helpers and by the
396 * transitional plane helpers, but it is optional.
397 */
398 void (*atomic_flush)(struct drm_crtc *crtc,
399 struct drm_crtc_state *old_crtc_state);
400
401 /**
402 * @atomic_enable:
403 *
404 * This callback should be used to enable the CRTC. With the atomic
405 * drivers it is called before all encoders connected to this CRTC are
406 * enabled through the encoder's own &drm_encoder_helper_funcs.enable
407 * hook. If that sequence is too simple drivers can just add their own
408 * hooks and call it from this CRTC callback here by looping over all
409 * encoders connected to it using for_each_encoder_on_crtc().
410 *
411 * This hook is used only by atomic helpers, for symmetry with
412 * @atomic_disable. Atomic drivers don't need to implement it if there's
413 * no need to enable anything at the CRTC level. To ensure that runtime
414 * PM handling (using either DPMS or the new "ACTIVE" property) works
415 * @atomic_enable must be the inverse of @atomic_disable for atomic
416 * drivers.
417 *
418 * Drivers can use the @old_crtc_state input parameter if the operations
419 * needed to enable the CRTC don't depend solely on the new state but
420 * also on the transition between the old state and the new state.
421 */
422 void (*atomic_enable)(struct drm_crtc *crtc,
423 struct drm_crtc_state *old_crtc_state);
424
425 /**
426 * @atomic_disable:
427 *
428 * This callback should be used to disable the CRTC. With the atomic
429 * drivers it is called after all encoders connected to this CRTC have
430 * been shut off already using their own
431 * &drm_encoder_helper_funcs.disable hook. If that sequence is too
432 * simple drivers can just add their own hooks and call it from this
433 * CRTC callback here by looping over all encoders connected to it using
434 * for_each_encoder_on_crtc().
435 *
436 * This hook is used only by atomic helpers. Atomic drivers don't
437 * need to implement it if there's no need to disable anything at the
438 * CRTC level.
439 *
440 * Comparing to @disable, this one provides the additional input
441 * parameter @old_crtc_state which could be used to access the old
442 * state. Atomic drivers should consider to use this one instead
443 * of @disable.
444 */
445 void (*atomic_disable)(struct drm_crtc *crtc,
446 struct drm_crtc_state *old_crtc_state);
447};
448
449/**
450 * drm_crtc_helper_add - sets the helper vtable for a crtc
451 * @crtc: DRM CRTC
452 * @funcs: helper vtable to set for @crtc
453 */
454static inline void drm_crtc_helper_add(struct drm_crtc *crtc,
455 const struct drm_crtc_helper_funcs *funcs)
456{
457 crtc->helper_private = funcs;
458}
459
460/**
461 * struct drm_encoder_helper_funcs - helper operations for encoders
462 *
463 * These hooks are used by the legacy CRTC helpers, the transitional plane
464 * helpers and the new atomic modesetting helpers.
465 */
466struct drm_encoder_helper_funcs {
467 /**
468 * @dpms:
469 *
470 * Callback to control power levels on the encoder. If the mode passed in
471 * is unsupported, the provider must use the next lowest power level.
472 * This is used by the legacy encoder helpers to implement DPMS
473 * functionality in drm_helper_connector_dpms().
474 *
475 * This callback is also used to disable an encoder by calling it with
476 * DRM_MODE_DPMS_OFF if the @disable hook isn't used.
477 *
478 * This callback is used by the legacy CRTC helpers. Atomic helpers
479 * also support using this hook for enabling and disabling an encoder to
480 * facilitate transitions to atomic, but it is deprecated. Instead
481 * @enable and @disable should be used.
482 */
483 void (*dpms)(struct drm_encoder *encoder, int mode);
484
485 /**
486 * @mode_valid:
487 *
488 * This callback is used to check if a specific mode is valid in this
489 * encoder. This should be implemented if the encoder has some sort
490 * of restriction in the modes it can display. For example, a given
491 * encoder may be responsible to set a clock value. If the clock can
492 * not produce all the values for the available modes then this callback
493 * can be used to restrict the number of modes to only the ones that
494 * can be displayed.
495 *
496 * This hook is used by the probe helpers to filter the mode list in
497 * drm_helper_probe_single_connector_modes(), and it is used by the
498 * atomic helpers to validate modes supplied by userspace in
499 * drm_atomic_helper_check_modeset().
500 *
501 * This function is optional.
502 *
503 * NOTE:
504 *
505 * Since this function is both called from the check phase of an atomic
506 * commit, and the mode validation in the probe paths it is not allowed
507 * to look at anything else but the passed-in mode, and validate it
508 * against configuration-invariant hardward constraints. Any further
509 * limits which depend upon the configuration can only be checked in
510 * @mode_fixup or @atomic_check.
511 *
512 * RETURNS:
513 *
514 * drm_mode_status Enum
515 */
516 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc,
517 const struct drm_display_mode *mode);
518
519 /**
520 * @mode_fixup:
521 *
522 * This callback is used to validate and adjust a mode. The parameter
523 * mode is the display mode that should be fed to the next element in
524 * the display chain, either the final &drm_connector or a &drm_bridge.
525 * The parameter adjusted_mode is the input mode the encoder requires. It
526 * can be modified by this callback and does not need to match mode. See
527 * also &drm_crtc_state.adjusted_mode for more details.
528 *
529 * This function is used by both legacy CRTC helpers and atomic helpers.
530 * This hook is optional.
531 *
532 * NOTE:
533 *
534 * This function is called in the check phase of atomic modesets, which
535 * can be aborted for any reason (including on userspace's request to
536 * just check whether a configuration would be possible). Atomic drivers
537 * MUST NOT touch any persistent state (hardware or software) or data
538 * structures except the passed in adjusted_mode parameter.
539 *
540 * This is in contrast to the legacy CRTC helpers where this was
541 * allowed.
542 *
543 * Atomic drivers which need to inspect and adjust more state should
544 * instead use the @atomic_check callback. If @atomic_check is used,
545 * this hook isn't called since @atomic_check allows a strict superset
546 * of the functionality of @mode_fixup.
547 *
548 * Also beware that userspace can request its own custom modes, neither
549 * core nor helpers filter modes to the list of probe modes reported by
550 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
551 * that modes are filtered consistently put any encoder constraints and
552 * limits checks into @mode_valid.
553 *
554 * RETURNS:
555 *
556 * True if an acceptable configuration is possible, false if the modeset
557 * operation should be rejected.
558 */
559 bool (*mode_fixup)(struct drm_encoder *encoder,
560 const struct drm_display_mode *mode,
561 struct drm_display_mode *adjusted_mode);
562
563 /**
564 * @prepare:
565 *
566 * This callback should prepare the encoder for a subsequent modeset,
567 * which in practice means the driver should disable the encoder if it
568 * is running. Most drivers ended up implementing this by calling their
569 * @dpms hook with DRM_MODE_DPMS_OFF.
570 *
571 * This callback is used by the legacy CRTC helpers. Atomic helpers
572 * also support using this hook for disabling an encoder to facilitate
573 * transitions to atomic, but it is deprecated. Instead @disable should
574 * be used.
575 */
576 void (*prepare)(struct drm_encoder *encoder);
577
578 /**
579 * @commit:
580 *
581 * This callback should commit the new mode on the encoder after a modeset,
582 * which in practice means the driver should enable the encoder. Most
583 * drivers ended up implementing this by calling their @dpms hook with
584 * DRM_MODE_DPMS_ON.
585 *
586 * This callback is used by the legacy CRTC helpers. Atomic helpers
587 * also support using this hook for enabling an encoder to facilitate
588 * transitions to atomic, but it is deprecated. Instead @enable should
589 * be used.
590 */
591 void (*commit)(struct drm_encoder *encoder);
592
593 /**
594 * @mode_set:
595 *
596 * This callback is used to update the display mode of an encoder.
597 *
598 * Note that the display pipe is completely off when this function is
599 * called. Drivers which need hardware to be running before they program
600 * the new display mode (because they implement runtime PM) should not
601 * use this hook, because the helper library calls it only once and not
602 * every time the display pipeline is suspend using either DPMS or the
603 * new "ACTIVE" property. Such drivers should instead move all their
604 * encoder setup into the @enable callback.
605 *
606 * This callback is used both by the legacy CRTC helpers and the atomic
607 * modeset helpers. It is optional in the atomic helpers.
608 *
609 * NOTE:
610 *
611 * If the driver uses the atomic modeset helpers and needs to inspect
612 * the connector state or connector display info during mode setting,
613 * @atomic_mode_set can be used instead.
614 */
615 void (*mode_set)(struct drm_encoder *encoder,
616 struct drm_display_mode *mode,
617 struct drm_display_mode *adjusted_mode);
618
619 /**
620 * @atomic_mode_set:
621 *
622 * This callback is used to update the display mode of an encoder.
623 *
624 * Note that the display pipe is completely off when this function is
625 * called. Drivers which need hardware to be running before they program
626 * the new display mode (because they implement runtime PM) should not
627 * use this hook, because the helper library calls it only once and not
628 * every time the display pipeline is suspended using either DPMS or the
629 * new "ACTIVE" property. Such drivers should instead move all their
630 * encoder setup into the @enable callback.
631 *
632 * This callback is used by the atomic modeset helpers in place of the
633 * @mode_set callback, if set by the driver. It is optional and should
634 * be used instead of @mode_set if the driver needs to inspect the
635 * connector state or display info, since there is no direct way to
636 * go from the encoder to the current connector.
637 */
638 void (*atomic_mode_set)(struct drm_encoder *encoder,
639 struct drm_crtc_state *crtc_state,
640 struct drm_connector_state *conn_state);
641
642 /**
643 * @get_crtc:
644 *
645 * This callback is used by the legacy CRTC helpers to work around
646 * deficiencies in its own book-keeping.
647 *
648 * Do not use, use atomic helpers instead, which get the book keeping
649 * right.
650 *
651 * FIXME:
652 *
653 * Currently only nouveau is using this, and as soon as nouveau is
654 * atomic we can ditch this hook.
655 */
656 struct drm_crtc *(*get_crtc)(struct drm_encoder *encoder);
657
658 /**
659 * @detect:
660 *
661 * This callback can be used by drivers who want to do detection on the
662 * encoder object instead of in connector functions.
663 *
664 * It is not used by any helper and therefore has purely driver-specific
665 * semantics. New drivers shouldn't use this and instead just implement
666 * their own private callbacks.
667 *
668 * FIXME:
669 *
670 * This should just be converted into a pile of driver vfuncs.
671 * Currently radeon, amdgpu and nouveau are using it.
672 */
673 enum drm_connector_status (*detect)(struct drm_encoder *encoder,
674 struct drm_connector *connector);
675
676 /**
677 * @disable:
678 *
679 * This callback should be used to disable the encoder. With the atomic
680 * drivers it is called before this encoder's CRTC has been shut off
681 * using their own &drm_crtc_helper_funcs.disable hook. If that
682 * sequence is too simple drivers can just add their own driver private
683 * encoder hooks and call them from CRTC's callback by looping over all
684 * encoders connected to it using for_each_encoder_on_crtc().
685 *
686 * This hook is used both by legacy CRTC helpers and atomic helpers.
687 * Atomic drivers don't need to implement it if there's no need to
688 * disable anything at the encoder level. To ensure that runtime PM
689 * handling (using either DPMS or the new "ACTIVE" property) works
690 * @disable must be the inverse of @enable for atomic drivers.
691 *
692 * NOTE:
693 *
694 * With legacy CRTC helpers there's a big semantic difference between
695 * @disable and other hooks (like @prepare or @dpms) used to shut down a
696 * encoder: @disable is only called when also logically disabling the
697 * display pipeline and needs to release any resources acquired in
698 * @mode_set (like shared PLLs, or again release pinned framebuffers).
699 *
700 * Therefore @disable must be the inverse of @mode_set plus @commit for
701 * drivers still using legacy CRTC helpers, which is different from the
702 * rules under atomic.
703 */
704 void (*disable)(struct drm_encoder *encoder);
705
706 /**
707 * @enable:
708 *
709 * This callback should be used to enable the encoder. With the atomic
710 * drivers it is called after this encoder's CRTC has been enabled using
711 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is
712 * too simple drivers can just add their own driver private encoder
713 * hooks and call them from CRTC's callback by looping over all encoders
714 * connected to it using for_each_encoder_on_crtc().
715 *
716 * This hook is used only by atomic helpers, for symmetry with @disable.
717 * Atomic drivers don't need to implement it if there's no need to
718 * enable anything at the encoder level. To ensure that runtime PM handling
719 * (using either DPMS or the new "ACTIVE" property) works
720 * @enable must be the inverse of @disable for atomic drivers.
721 */
722 void (*enable)(struct drm_encoder *encoder);
723
724 /**
725 * @atomic_check:
726 *
727 * This callback is used to validate encoder state for atomic drivers.
728 * Since the encoder is the object connecting the CRTC and connector it
729 * gets passed both states, to be able to validate interactions and
730 * update the CRTC to match what the encoder needs for the requested
731 * connector.
732 *
733 * Since this provides a strict superset of the functionality of
734 * @mode_fixup (the requested and adjusted modes are both available
735 * through the passed in &struct drm_crtc_state) @mode_fixup is not
736 * called when @atomic_check is implemented.
737 *
738 * This function is used by the atomic helpers, but it is optional.
739 *
740 * NOTE:
741 *
742 * This function is called in the check phase of an atomic update. The
743 * driver is not allowed to change anything outside of the free-standing
744 * state objects passed-in or assembled in the overall &drm_atomic_state
745 * update tracking structure.
746 *
747 * Also beware that userspace can request its own custom modes, neither
748 * core nor helpers filter modes to the list of probe modes reported by
749 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
750 * that modes are filtered consistently put any encoder constraints and
751 * limits checks into @mode_valid.
752 *
753 * RETURNS:
754 *
755 * 0 on success, -EINVAL if the state or the transition can't be
756 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
757 * attempt to obtain another state object ran into a &drm_modeset_lock
758 * deadlock.
759 */
760 int (*atomic_check)(struct drm_encoder *encoder,
761 struct drm_crtc_state *crtc_state,
762 struct drm_connector_state *conn_state);
763};
764
765/**
766 * drm_encoder_helper_add - sets the helper vtable for an encoder
767 * @encoder: DRM encoder
768 * @funcs: helper vtable to set for @encoder
769 */
770static inline void drm_encoder_helper_add(struct drm_encoder *encoder,
771 const struct drm_encoder_helper_funcs *funcs)
772{
773 encoder->helper_private = funcs;
774}
775
776/**
777 * struct drm_connector_helper_funcs - helper operations for connectors
778 *
779 * These functions are used by the atomic and legacy modeset helpers and by the
780 * probe helpers.
781 */
782struct drm_connector_helper_funcs {
783 /**
784 * @get_modes:
785 *
786 * This function should fill in all modes currently valid for the sink
787 * into the &drm_connector.probed_modes list. It should also update the
788 * EDID property by calling drm_connector_update_edid_property().
789 *
790 * The usual way to implement this is to cache the EDID retrieved in the
791 * probe callback somewhere in the driver-private connector structure.
792 * In this function drivers then parse the modes in the EDID and add
793 * them by calling drm_add_edid_modes(). But connectors that driver a
794 * fixed panel can also manually add specific modes using
795 * drm_mode_probed_add(). Drivers which manually add modes should also
796 * make sure that the &drm_connector.display_info,
797 * &drm_connector.width_mm and &drm_connector.height_mm fields are
798 * filled in.
799 *
800 * Virtual drivers that just want some standard VESA mode with a given
801 * resolution can call drm_add_modes_noedid(), and mark the preferred
802 * one using drm_set_preferred_mode().
803 *
804 * This function is only called after the @detect hook has indicated
805 * that a sink is connected and when the EDID isn't overridden through
806 * sysfs or the kernel commandline.
807 *
808 * This callback is used by the probe helpers in e.g.
809 * drm_helper_probe_single_connector_modes().
810 *
811 * To avoid races with concurrent connector state updates, the helper
812 * libraries always call this with the &drm_mode_config.connection_mutex
813 * held. Because of this it's safe to inspect &drm_connector->state.
814 *
815 * RETURNS:
816 *
817 * The number of modes added by calling drm_mode_probed_add().
818 */
819 int (*get_modes)(struct drm_connector *connector);
820
821 /**
822 * @detect_ctx:
823 *
824 * Check to see if anything is attached to the connector. The parameter
825 * force is set to false whilst polling, true when checking the
826 * connector due to a user request. force can be used by the driver to
827 * avoid expensive, destructive operations during automated probing.
828 *
829 * This callback is optional, if not implemented the connector will be
830 * considered as always being attached.
831 *
832 * This is the atomic version of &drm_connector_funcs.detect.
833 *
834 * To avoid races against concurrent connector state updates, the
835 * helper libraries always call this with ctx set to a valid context,
836 * and &drm_mode_config.connection_mutex will always be locked with
837 * the ctx parameter set to this ctx. This allows taking additional
838 * locks as required.
839 *
840 * RETURNS:
841 *
842 * &drm_connector_status indicating the connector's status,
843 * or the error code returned by drm_modeset_lock(), -EDEADLK.
844 */
845 int (*detect_ctx)(struct drm_connector *connector,
846 struct drm_modeset_acquire_ctx *ctx,
847 bool force);
848
849 /**
850 * @mode_valid:
851 *
852 * Callback to validate a mode for a connector, irrespective of the
853 * specific display configuration.
854 *
855 * This callback is used by the probe helpers to filter the mode list
856 * (which is usually derived from the EDID data block from the sink).
857 * See e.g. drm_helper_probe_single_connector_modes().
858 *
859 * This function is optional.
860 *
861 * NOTE:
862 *
863 * This only filters the mode list supplied to userspace in the
864 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid,
865 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid,
866 * which are also called by the atomic helpers from
867 * drm_atomic_helper_check_modeset(). This allows userspace to force and
868 * ignore sink constraint (like the pixel clock limits in the screen's
869 * EDID), which is useful for e.g. testing, or working around a broken
870 * EDID. Any source hardware constraint (which always need to be
871 * enforced) therefore should be checked in one of the above callbacks,
872 * and not this one here.
873 *
874 * To avoid races with concurrent connector state updates, the helper
875 * libraries always call this with the &drm_mode_config.connection_mutex
876 * held. Because of this it's safe to inspect &drm_connector->state.
877 *
878 * RETURNS:
879 *
880 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum
881 * drm_mode_status.
882 */
883 enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
884 struct drm_display_mode *mode);
885 /**
886 * @best_encoder:
887 *
888 * This function should select the best encoder for the given connector.
889 *
890 * This function is used by both the atomic helpers (in the
891 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC
892 * helpers.
893 *
894 * NOTE:
895 *
896 * In atomic drivers this function is called in the check phase of an
897 * atomic update. The driver is not allowed to change or inspect
898 * anything outside of arguments passed-in. Atomic drivers which need to
899 * inspect dynamic configuration state should instead use
900 * @atomic_best_encoder.
901 *
902 * You can leave this function to NULL if the connector is only
903 * attached to a single encoder and you are using the atomic helpers.
904 * In this case, the core will call drm_atomic_helper_best_encoder()
905 * for you.
906 *
907 * RETURNS:
908 *
909 * Encoder that should be used for the given connector and connector
910 * state, or NULL if no suitable encoder exists. Note that the helpers
911 * will ensure that encoders aren't used twice, drivers should not check
912 * for this.
913 */
914 struct drm_encoder *(*best_encoder)(struct drm_connector *connector);
915
916 /**
917 * @atomic_best_encoder:
918 *
919 * This is the atomic version of @best_encoder for atomic drivers which
920 * need to select the best encoder depending upon the desired
921 * configuration and can't select it statically.
922 *
923 * This function is used by drm_atomic_helper_check_modeset().
924 * If it is not implemented, the core will fallback to @best_encoder
925 * (or drm_atomic_helper_best_encoder() if @best_encoder is NULL).
926 *
927 * NOTE:
928 *
929 * This function is called in the check phase of an atomic update. The
930 * driver is not allowed to change anything outside of the free-standing
931 * state objects passed-in or assembled in the overall &drm_atomic_state
932 * update tracking structure.
933 *
934 * RETURNS:
935 *
936 * Encoder that should be used for the given connector and connector
937 * state, or NULL if no suitable encoder exists. Note that the helpers
938 * will ensure that encoders aren't used twice, drivers should not check
939 * for this.
940 */
941 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector,
942 struct drm_connector_state *connector_state);
943
944 /**
945 * @atomic_check:
946 *
947 * This hook is used to validate connector state. This function is
948 * called from &drm_atomic_helper_check_modeset, and is called when
949 * a connector property is set, or a modeset on the crtc is forced.
950 *
951 * Because &drm_atomic_helper_check_modeset may be called multiple times,
952 * this function should handle being called multiple times as well.
953 *
954 * This function is also allowed to inspect any other object's state and
955 * can add more state objects to the atomic commit if needed. Care must
956 * be taken though to ensure that state check and compute functions for
957 * these added states are all called, and derived state in other objects
958 * all updated. Again the recommendation is to just call check helpers
959 * until a maximal configuration is reached.
960 *
961 * NOTE:
962 *
963 * This function is called in the check phase of an atomic update. The
964 * driver is not allowed to change anything outside of the free-standing
965 * state objects passed-in or assembled in the overall &drm_atomic_state
966 * update tracking structure.
967 *
968 * RETURNS:
969 *
970 * 0 on success, -EINVAL if the state or the transition can't be
971 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
972 * attempt to obtain another state object ran into a &drm_modeset_lock
973 * deadlock.
974 */
975 int (*atomic_check)(struct drm_connector *connector,
976 struct drm_connector_state *state);
977
978 /**
979 * @atomic_commit:
980 *
981 * This hook is to be used by drivers implementing writeback connectors
982 * that need a point when to commit the writeback job to the hardware.
983 * The writeback_job to commit is available in
984 * &drm_connector_state.writeback_job.
985 *
986 * This hook is optional.
987 *
988 * This callback is used by the atomic modeset helpers.
989 */
990 void (*atomic_commit)(struct drm_connector *connector,
991 struct drm_connector_state *state);
992};
993
994/**
995 * drm_connector_helper_add - sets the helper vtable for a connector
996 * @connector: DRM connector
997 * @funcs: helper vtable to set for @connector
998 */
999static inline void drm_connector_helper_add(struct drm_connector *connector,
1000 const struct drm_connector_helper_funcs *funcs)
1001{
1002 connector->helper_private = funcs;
1003}
1004
1005/**
1006 * struct drm_plane_helper_funcs - helper operations for planes
1007 *
1008 * These functions are used by the atomic helpers and by the transitional plane
1009 * helpers.
1010 */
1011struct drm_plane_helper_funcs {
1012 /**
1013 * @prepare_fb:
1014 *
1015 * This hook is to prepare a framebuffer for scanout by e.g. pinning
1016 * its backing storage or relocating it into a contiguous block of
1017 * VRAM. Other possible preparatory work includes flushing caches.
1018 *
1019 * This function must not block for outstanding rendering, since it is
1020 * called in the context of the atomic IOCTL even for async commits to
1021 * be able to return any errors to userspace. Instead the recommended
1022 * way is to fill out the &drm_plane_state.fence of the passed-in
1023 * &drm_plane_state. If the driver doesn't support native fences then
1024 * equivalent functionality should be implemented through private
1025 * members in the plane structure.
1026 *
1027 * Drivers which always have their buffers pinned should use
1028 * drm_gem_fb_prepare_fb() for this hook.
1029 *
1030 * The helpers will call @cleanup_fb with matching arguments for every
1031 * successful call to this hook.
1032 *
1033 * This callback is used by the atomic modeset helpers and by the
1034 * transitional plane helpers, but it is optional.
1035 *
1036 * RETURNS:
1037 *
1038 * 0 on success or one of the following negative error codes allowed by
1039 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers
1040 * this callback is the only one which can fail an atomic commit,
1041 * everything else must complete successfully.
1042 */
1043 int (*prepare_fb)(struct drm_plane *plane,
1044 struct drm_plane_state *new_state);
1045 /**
1046 * @cleanup_fb:
1047 *
1048 * This hook is called to clean up any resources allocated for the given
1049 * framebuffer and plane configuration in @prepare_fb.
1050 *
1051 * This callback is used by the atomic modeset helpers and by the
1052 * transitional plane helpers, but it is optional.
1053 */
1054 void (*cleanup_fb)(struct drm_plane *plane,
1055 struct drm_plane_state *old_state);
1056
1057 /**
1058 * @atomic_check:
1059 *
1060 * Drivers should check plane specific constraints in this hook.
1061 *
1062 * When using drm_atomic_helper_check_planes() plane's @atomic_check
1063 * hooks are called before the ones for CRTCs, which allows drivers to
1064 * request shared resources that the CRTC controls here. For more
1065 * complicated dependencies the driver can call the provided check helpers
1066 * multiple times until the computed state has a final configuration and
1067 * everything has been checked.
1068 *
1069 * This function is also allowed to inspect any other object's state and
1070 * can add more state objects to the atomic commit if needed. Care must
1071 * be taken though to ensure that state check and compute functions for
1072 * these added states are all called, and derived state in other objects
1073 * all updated. Again the recommendation is to just call check helpers
1074 * until a maximal configuration is reached.
1075 *
1076 * This callback is used by the atomic modeset helpers and by the
1077 * transitional plane helpers, but it is optional.
1078 *
1079 * NOTE:
1080 *
1081 * This function is called in the check phase of an atomic update. The
1082 * driver is not allowed to change anything outside of the free-standing
1083 * state objects passed-in or assembled in the overall &drm_atomic_state
1084 * update tracking structure.
1085 *
1086 * RETURNS:
1087 *
1088 * 0 on success, -EINVAL if the state or the transition can't be
1089 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an
1090 * attempt to obtain another state object ran into a &drm_modeset_lock
1091 * deadlock.
1092 */
1093 int (*atomic_check)(struct drm_plane *plane,
1094 struct drm_plane_state *state);
1095
1096 /**
1097 * @atomic_update:
1098 *
1099 * Drivers should use this function to update the plane state. This
1100 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and
1101 * drm_crtc_helper_funcs.atomic_flush callbacks.
1102 *
1103 * Note that the power state of the display pipe when this function is
1104 * called depends upon the exact helpers and calling sequence the driver
1105 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1106 * the tradeoffs and variants of plane commit helpers.
1107 *
1108 * This callback is used by the atomic modeset helpers and by the
1109 * transitional plane helpers, but it is optional.
1110 */
1111 void (*atomic_update)(struct drm_plane *plane,
1112 struct drm_plane_state *old_state);
1113 /**
1114 * @atomic_disable:
1115 *
1116 * Drivers should use this function to unconditionally disable a plane.
1117 * This hook is called in-between the
1118 * &drm_crtc_helper_funcs.atomic_begin and
1119 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to
1120 * @atomic_update, which will be called for disabling planes, too, if
1121 * the @atomic_disable hook isn't implemented.
1122 *
1123 * This hook is also useful to disable planes in preparation of a modeset,
1124 * by calling drm_atomic_helper_disable_planes_on_crtc() from the
1125 * &drm_crtc_helper_funcs.disable hook.
1126 *
1127 * Note that the power state of the display pipe when this function is
1128 * called depends upon the exact helpers and calling sequence the driver
1129 * has picked. See drm_atomic_helper_commit_planes() for a discussion of
1130 * the tradeoffs and variants of plane commit helpers.
1131 *
1132 * This callback is used by the atomic modeset helpers and by the
1133 * transitional plane helpers, but it is optional.
1134 */
1135 void (*atomic_disable)(struct drm_plane *plane,
1136 struct drm_plane_state *old_state);
1137
1138 /**
1139 * @atomic_async_check:
1140 *
1141 * Drivers should set this function pointer to check if the plane state
1142 * can be updated in a async fashion. Here async means "not vblank
1143 * synchronized".
1144 *
1145 * This hook is called by drm_atomic_async_check() to establish if a
1146 * given update can be committed asynchronously, that is, if it can
1147 * jump ahead of the state currently queued for update.
1148 *
1149 * RETURNS:
1150 *
1151 * Return 0 on success and any error returned indicates that the update
1152 * can not be applied in asynchronous manner.
1153 */
1154 int (*atomic_async_check)(struct drm_plane *plane,
1155 struct drm_plane_state *state);
1156
1157 /**
1158 * @atomic_async_update:
1159 *
1160 * Drivers should set this function pointer to perform asynchronous
1161 * updates of planes, that is, jump ahead of the currently queued
1162 * state and update the plane. Here async means "not vblank
1163 * synchronized".
1164 *
1165 * This hook is called by drm_atomic_helper_async_commit().
1166 *
1167 * An async update will happen on legacy cursor updates. An async
1168 * update won't happen if there is an outstanding commit modifying
1169 * the same plane.
1170 *
1171 * Note that unlike &drm_plane_helper_funcs.atomic_update this hook
1172 * takes the new &drm_plane_state as parameter. When doing async_update
1173 * drivers shouldn't replace the &drm_plane_state but update the
1174 * current one with the new plane configurations in the new
1175 * plane_state.
1176 *
1177 * FIXME:
1178 * - It only works for single plane updates
1179 * - Async Pageflips are not supported yet
1180 * - Some hw might still scan out the old buffer until the next
1181 * vblank, however we let go of the fb references as soon as
1182 * we run this hook. For now drivers must implement their own workers
1183 * for deferring if needed, until a common solution is created.
1184 */
1185 void (*atomic_async_update)(struct drm_plane *plane,
1186 struct drm_plane_state *new_state);
1187};
1188
1189/**
1190 * drm_plane_helper_add - sets the helper vtable for a plane
1191 * @plane: DRM plane
1192 * @funcs: helper vtable to set for @plane
1193 */
1194static inline void drm_plane_helper_add(struct drm_plane *plane,
1195 const struct drm_plane_helper_funcs *funcs)
1196{
1197 plane->helper_private = funcs;
1198}
1199
1200/**
1201 * struct drm_mode_config_helper_funcs - global modeset helper operations
1202 *
1203 * These helper functions are used by the atomic helpers.
1204 */
1205struct drm_mode_config_helper_funcs {
1206 /**
1207 * @atomic_commit_tail:
1208 *
1209 * This hook is used by the default atomic_commit() hook implemented in
1210 * drm_atomic_helper_commit() together with the nonblocking commit
1211 * helpers (see drm_atomic_helper_setup_commit() for a starting point)
1212 * to implement blocking and nonblocking commits easily. It is not used
1213 * by the atomic helpers
1214 *
1215 * This function is called when the new atomic state has already been
1216 * swapped into the various state pointers. The passed in state
1217 * therefore contains copies of the old/previous state. This hook should
1218 * commit the new state into hardware. Note that the helpers have
1219 * already waited for preceeding atomic commits and fences, but drivers
1220 * can add more waiting calls at the start of their implementation, e.g.
1221 * to wait for driver-internal request for implicit syncing, before
1222 * starting to commit the update to the hardware.
1223 *
1224 * After the atomic update is committed to the hardware this hook needs
1225 * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate
1226 * to be executed by the hardware, for example using
1227 * drm_atomic_helper_wait_for_vblanks() or
1228 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old
1229 * framebuffers using drm_atomic_helper_cleanup_planes().
1230 *
1231 * When disabling a CRTC this hook _must_ stall for the commit to
1232 * complete. Vblank waits don't work on disabled CRTC, hence the core
1233 * can't take care of this. And it also can't rely on the vblank event,
1234 * since that can be signalled already when the screen shows black,
1235 * which can happen much earlier than the last hardware access needed to
1236 * shut off the display pipeline completely.
1237 *
1238 * This hook is optional, the default implementation is
1239 * drm_atomic_helper_commit_tail().
1240 */
1241 void (*atomic_commit_tail)(struct drm_atomic_state *state);
1242};
1243
1244#endif
1245