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1/*
2 * Copyright (c) 2016 Intel Corporation
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#ifndef __DRM_BRIDGE_H__
24#define __DRM_BRIDGE_H__
25
26#include <linux/ctype.h>
27#include <linux/list.h>
28#include <linux/mutex.h>
29
30#include <drm/drm_atomic.h>
31#include <drm/drm_encoder.h>
32#include <drm/drm_mode_object.h>
33#include <drm/drm_modes.h>
34
35struct drm_bridge;
36struct drm_bridge_timings;
37struct drm_connector;
38struct drm_display_info;
39struct drm_panel;
40struct edid;
41struct i2c_adapter;
42
43/**
44 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
45 */
46enum drm_bridge_attach_flags {
47 /**
48 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge
49 * shall not create a drm_connector.
50 */
51 DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),
52};
53
54/**
55 * struct drm_bridge_funcs - drm_bridge control functions
56 */
57struct drm_bridge_funcs {
58 /**
59 * @attach:
60 *
61 * This callback is invoked whenever our bridge is being attached to a
62 * &drm_encoder. The flags argument tunes the behaviour of the attach
63 * operation (see DRM_BRIDGE_ATTACH_*).
64 *
65 * The @attach callback is optional.
66 *
67 * RETURNS:
68 *
69 * Zero on success, error code on failure.
70 */
71 int (*attach)(struct drm_bridge *bridge,
72 enum drm_bridge_attach_flags flags);
73
74 /**
75 * @detach:
76 *
77 * This callback is invoked whenever our bridge is being detached from a
78 * &drm_encoder.
79 *
80 * The @detach callback is optional.
81 */
82 void (*detach)(struct drm_bridge *bridge);
83
84 /**
85 * @mode_valid:
86 *
87 * This callback is used to check if a specific mode is valid in this
88 * bridge. This should be implemented if the bridge has some sort of
89 * restriction in the modes it can display. For example, a given bridge
90 * may be responsible to set a clock value. If the clock can not
91 * produce all the values for the available modes then this callback
92 * can be used to restrict the number of modes to only the ones that
93 * can be displayed.
94 *
95 * This hook is used by the probe helpers to filter the mode list in
96 * drm_helper_probe_single_connector_modes(), and it is used by the
97 * atomic helpers to validate modes supplied by userspace in
98 * drm_atomic_helper_check_modeset().
99 *
100 * The @mode_valid callback is optional.
101 *
102 * NOTE:
103 *
104 * Since this function is both called from the check phase of an atomic
105 * commit, and the mode validation in the probe paths it is not allowed
106 * to look at anything else but the passed-in mode, and validate it
107 * against configuration-invariant hardward constraints. Any further
108 * limits which depend upon the configuration can only be checked in
109 * @mode_fixup.
110 *
111 * RETURNS:
112 *
113 * drm_mode_status Enum
114 */
115 enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
116 const struct drm_display_info *info,
117 const struct drm_display_mode *mode);
118
119 /**
120 * @mode_fixup:
121 *
122 * This callback is used to validate and adjust a mode. The parameter
123 * mode is the display mode that should be fed to the next element in
124 * the display chain, either the final &drm_connector or the next
125 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
126 * requires. It can be modified by this callback and does not need to
127 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
128 *
129 * This is the only hook that allows a bridge to reject a modeset. If
130 * this function passes all other callbacks must succeed for this
131 * configuration.
132 *
133 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
134 * is not called when &drm_bridge_funcs.atomic_check() is implemented,
135 * so only one of them should be provided.
136 *
137 * NOTE:
138 *
139 * This function is called in the check phase of atomic modesets, which
140 * can be aborted for any reason (including on userspace's request to
141 * just check whether a configuration would be possible). Drivers MUST
142 * NOT touch any persistent state (hardware or software) or data
143 * structures except the passed in @state parameter.
144 *
145 * Also beware that userspace can request its own custom modes, neither
146 * core nor helpers filter modes to the list of probe modes reported by
147 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
148 * that modes are filtered consistently put any bridge constraints and
149 * limits checks into @mode_valid.
150 *
151 * RETURNS:
152 *
153 * True if an acceptable configuration is possible, false if the modeset
154 * operation should be rejected.
155 */
156 bool (*mode_fixup)(struct drm_bridge *bridge,
157 const struct drm_display_mode *mode,
158 struct drm_display_mode *adjusted_mode);
159 /**
160 * @disable:
161 *
162 * This callback should disable the bridge. It is called right before
163 * the preceding element in the display pipe is disabled. If the
164 * preceding element is a bridge this means it's called before that
165 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
166 * it's called right before the &drm_encoder_helper_funcs.disable,
167 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
168 * hook.
169 *
170 * The bridge can assume that the display pipe (i.e. clocks and timing
171 * signals) feeding it is still running when this callback is called.
172 *
173 * The @disable callback is optional.
174 *
175 * NOTE:
176 *
177 * This is deprecated, do not use!
178 * New drivers shall use &drm_bridge_funcs.atomic_disable.
179 */
180 void (*disable)(struct drm_bridge *bridge);
181
182 /**
183 * @post_disable:
184 *
185 * This callback should disable the bridge. It is called right after the
186 * preceding element in the display pipe is disabled. If the preceding
187 * element is a bridge this means it's called after that bridge's
188 * @post_disable function. If the preceding element is a &drm_encoder
189 * it's called right after the encoder's
190 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
191 * or &drm_encoder_helper_funcs.dpms hook.
192 *
193 * The bridge must assume that the display pipe (i.e. clocks and timing
194 * singals) feeding it is no longer running when this callback is
195 * called.
196 *
197 * The @post_disable callback is optional.
198 *
199 * NOTE:
200 *
201 * This is deprecated, do not use!
202 * New drivers shall use &drm_bridge_funcs.atomic_post_disable.
203 */
204 void (*post_disable)(struct drm_bridge *bridge);
205
206 /**
207 * @mode_set:
208 *
209 * This callback should set the given mode on the bridge. It is called
210 * after the @mode_set callback for the preceding element in the display
211 * pipeline has been called already. If the bridge is the first element
212 * then this would be &drm_encoder_helper_funcs.mode_set. The display
213 * pipe (i.e. clocks and timing signals) is off when this function is
214 * called.
215 *
216 * The adjusted_mode parameter is the mode output by the CRTC for the
217 * first bridge in the chain. It can be different from the mode
218 * parameter that contains the desired mode for the connector at the end
219 * of the bridges chain, for instance when the first bridge in the chain
220 * performs scaling. The adjusted mode is mostly useful for the first
221 * bridge in the chain and is likely irrelevant for the other bridges.
222 *
223 * For atomic drivers the adjusted_mode is the mode stored in
224 * &drm_crtc_state.adjusted_mode.
225 *
226 * NOTE:
227 *
228 * This is deprecated, do not use!
229 * New drivers shall set their mode in the
230 * &drm_bridge_funcs.atomic_enable operation.
231 */
232 void (*mode_set)(struct drm_bridge *bridge,
233 const struct drm_display_mode *mode,
234 const struct drm_display_mode *adjusted_mode);
235 /**
236 * @pre_enable:
237 *
238 * This callback should enable the bridge. It is called right before
239 * the preceding element in the display pipe is enabled. If the
240 * preceding element is a bridge this means it's called before that
241 * bridge's @pre_enable function. If the preceding element is a
242 * &drm_encoder it's called right before the encoder's
243 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
244 * &drm_encoder_helper_funcs.dpms hook.
245 *
246 * The display pipe (i.e. clocks and timing signals) feeding this bridge
247 * will not yet be running when this callback is called. The bridge must
248 * not enable the display link feeding the next bridge in the chain (if
249 * there is one) when this callback is called.
250 *
251 * The @pre_enable callback is optional.
252 *
253 * NOTE:
254 *
255 * This is deprecated, do not use!
256 * New drivers shall use &drm_bridge_funcs.atomic_pre_enable.
257 */
258 void (*pre_enable)(struct drm_bridge *bridge);
259
260 /**
261 * @enable:
262 *
263 * This callback should enable the bridge. It is called right after
264 * the preceding element in the display pipe is enabled. If the
265 * preceding element is a bridge this means it's called after that
266 * bridge's @enable function. If the preceding element is a
267 * &drm_encoder it's called right after the encoder's
268 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
269 * &drm_encoder_helper_funcs.dpms hook.
270 *
271 * The bridge can assume that the display pipe (i.e. clocks and timing
272 * signals) feeding it is running when this callback is called. This
273 * callback must enable the display link feeding the next bridge in the
274 * chain if there is one.
275 *
276 * The @enable callback is optional.
277 *
278 * NOTE:
279 *
280 * This is deprecated, do not use!
281 * New drivers shall use &drm_bridge_funcs.atomic_enable.
282 */
283 void (*enable)(struct drm_bridge *bridge);
284
285 /**
286 * @atomic_pre_enable:
287 *
288 * This callback should enable the bridge. It is called right before
289 * the preceding element in the display pipe is enabled. If the
290 * preceding element is a bridge this means it's called before that
291 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
292 * element is a &drm_encoder it's called right before the encoder's
293 * &drm_encoder_helper_funcs.atomic_enable hook.
294 *
295 * The display pipe (i.e. clocks and timing signals) feeding this bridge
296 * will not yet be running when this callback is called. The bridge must
297 * not enable the display link feeding the next bridge in the chain (if
298 * there is one) when this callback is called.
299 *
300 * Note that this function will only be invoked in the context of an
301 * atomic commit. It will not be invoked from
302 * &drm_bridge_chain_pre_enable. It would be prudent to also provide an
303 * implementation of @pre_enable if you are expecting driver calls into
304 * &drm_bridge_chain_pre_enable.
305 *
306 * The @atomic_pre_enable callback is optional.
307 */
308 void (*atomic_pre_enable)(struct drm_bridge *bridge,
309 struct drm_bridge_state *old_bridge_state);
310
311 /**
312 * @atomic_enable:
313 *
314 * This callback should enable the bridge. It is called right after
315 * the preceding element in the display pipe is enabled. If the
316 * preceding element is a bridge this means it's called after that
317 * bridge's @atomic_enable or @enable function. If the preceding element
318 * is a &drm_encoder it's called right after the encoder's
319 * &drm_encoder_helper_funcs.atomic_enable hook.
320 *
321 * The bridge can assume that the display pipe (i.e. clocks and timing
322 * signals) feeding it is running when this callback is called. This
323 * callback must enable the display link feeding the next bridge in the
324 * chain if there is one.
325 *
326 * Note that this function will only be invoked in the context of an
327 * atomic commit. It will not be invoked from &drm_bridge_chain_enable.
328 * It would be prudent to also provide an implementation of @enable if
329 * you are expecting driver calls into &drm_bridge_chain_enable.
330 *
331 * The @atomic_enable callback is optional.
332 */
333 void (*atomic_enable)(struct drm_bridge *bridge,
334 struct drm_bridge_state *old_bridge_state);
335 /**
336 * @atomic_disable:
337 *
338 * This callback should disable the bridge. It is called right before
339 * the preceding element in the display pipe is disabled. If the
340 * preceding element is a bridge this means it's called before that
341 * bridge's @atomic_disable or @disable vfunc. If the preceding element
342 * is a &drm_encoder it's called right before the
343 * &drm_encoder_helper_funcs.atomic_disable hook.
344 *
345 * The bridge can assume that the display pipe (i.e. clocks and timing
346 * signals) feeding it is still running when this callback is called.
347 *
348 * Note that this function will only be invoked in the context of an
349 * atomic commit. It will not be invoked from
350 * &drm_bridge_chain_disable. It would be prudent to also provide an
351 * implementation of @disable if you are expecting driver calls into
352 * &drm_bridge_chain_disable.
353 *
354 * The @atomic_disable callback is optional.
355 */
356 void (*atomic_disable)(struct drm_bridge *bridge,
357 struct drm_bridge_state *old_bridge_state);
358
359 /**
360 * @atomic_post_disable:
361 *
362 * This callback should disable the bridge. It is called right after the
363 * preceding element in the display pipe is disabled. If the preceding
364 * element is a bridge this means it's called after that bridge's
365 * @atomic_post_disable or @post_disable function. If the preceding
366 * element is a &drm_encoder it's called right after the encoder's
367 * &drm_encoder_helper_funcs.atomic_disable hook.
368 *
369 * The bridge must assume that the display pipe (i.e. clocks and timing
370 * signals) feeding it is no longer running when this callback is
371 * called.
372 *
373 * Note that this function will only be invoked in the context of an
374 * atomic commit. It will not be invoked from
375 * &drm_bridge_chain_post_disable.
376 * It would be prudent to also provide an implementation of
377 * @post_disable if you are expecting driver calls into
378 * &drm_bridge_chain_post_disable.
379 *
380 * The @atomic_post_disable callback is optional.
381 */
382 void (*atomic_post_disable)(struct drm_bridge *bridge,
383 struct drm_bridge_state *old_bridge_state);
384
385 /**
386 * @atomic_duplicate_state:
387 *
388 * Duplicate the current bridge state object (which is guaranteed to be
389 * non-NULL).
390 *
391 * The atomic_duplicate_state hook is mandatory if the bridge
392 * implements any of the atomic hooks, and should be left unassigned
393 * otherwise. For bridges that don't subclass &drm_bridge_state, the
394 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
395 * used to implement this hook.
396 *
397 * RETURNS:
398 * A valid drm_bridge_state object or NULL if the allocation fails.
399 */
400 struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
401
402 /**
403 * @atomic_destroy_state:
404 *
405 * Destroy a bridge state object previously allocated by
406 * &drm_bridge_funcs.atomic_duplicate_state().
407 *
408 * The atomic_destroy_state hook is mandatory if the bridge implements
409 * any of the atomic hooks, and should be left unassigned otherwise.
410 * For bridges that don't subclass &drm_bridge_state, the
411 * drm_atomic_helper_bridge_destroy_state() helper function shall be
412 * used to implement this hook.
413 */
414 void (*atomic_destroy_state)(struct drm_bridge *bridge,
415 struct drm_bridge_state *state);
416
417 /**
418 * @atomic_get_output_bus_fmts:
419 *
420 * Return the supported bus formats on the output end of a bridge.
421 * The returned array must be allocated with kmalloc() and will be
422 * freed by the caller. If the allocation fails, NULL should be
423 * returned. num_output_fmts must be set to the returned array size.
424 * Formats listed in the returned array should be listed in decreasing
425 * preference order (the core will try all formats until it finds one
426 * that works).
427 *
428 * This method is only called on the last element of the bridge chain
429 * as part of the bus format negotiation process that happens in
430 * &drm_atomic_bridge_chain_select_bus_fmts().
431 * This method is optional. When not implemented, the core will
432 * fall back to &drm_connector.display_info.bus_formats[0] if
433 * &drm_connector.display_info.num_bus_formats > 0,
434 * or to MEDIA_BUS_FMT_FIXED otherwise.
435 */
436 u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
437 struct drm_bridge_state *bridge_state,
438 struct drm_crtc_state *crtc_state,
439 struct drm_connector_state *conn_state,
440 unsigned int *num_output_fmts);
441
442 /**
443 * @atomic_get_input_bus_fmts:
444 *
445 * Return the supported bus formats on the input end of a bridge for
446 * a specific output bus format.
447 *
448 * The returned array must be allocated with kmalloc() and will be
449 * freed by the caller. If the allocation fails, NULL should be
450 * returned. num_output_fmts must be set to the returned array size.
451 * Formats listed in the returned array should be listed in decreasing
452 * preference order (the core will try all formats until it finds one
453 * that works). When the format is not supported NULL should be
454 * returned and num_output_fmts should be set to 0.
455 *
456 * This method is called on all elements of the bridge chain as part of
457 * the bus format negotiation process that happens in
458 * drm_atomic_bridge_chain_select_bus_fmts().
459 * This method is optional. When not implemented, the core will bypass
460 * bus format negotiation on this element of the bridge without
461 * failing, and the previous element in the chain will be passed
462 * MEDIA_BUS_FMT_FIXED as its output bus format.
463 *
464 * Bridge drivers that need to support being linked to bridges that are
465 * not supporting bus format negotiation should handle the
466 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
467 * sensible default value or extracting this information from somewhere
468 * else (FW property, &drm_display_mode, &drm_display_info, ...)
469 *
470 * Note: Even if input format selection on the first bridge has no
471 * impact on the negotiation process (bus format negotiation stops once
472 * we reach the first element of the chain), drivers are expected to
473 * return accurate input formats as the input format may be used to
474 * configure the CRTC output appropriately.
475 */
476 u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
477 struct drm_bridge_state *bridge_state,
478 struct drm_crtc_state *crtc_state,
479 struct drm_connector_state *conn_state,
480 u32 output_fmt,
481 unsigned int *num_input_fmts);
482
483 /**
484 * @atomic_check:
485 *
486 * This method is responsible for checking bridge state correctness.
487 * It can also check the state of the surrounding components in chain
488 * to make sure the whole pipeline can work properly.
489 *
490 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
491 * order (from the last to the first bridge).
492 *
493 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
494 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
495 * one of them should be provided.
496 *
497 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
498 * &drm_bridge_state.output_bus_cfg.flags it should happen in
499 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
500 * field is set to the next bridge
501 * &drm_bridge_state.input_bus_cfg.flags value or
502 * &drm_connector.display_info.bus_flags if the bridge is the last
503 * element in the chain.
504 *
505 * RETURNS:
506 * zero if the check passed, a negative error code otherwise.
507 */
508 int (*atomic_check)(struct drm_bridge *bridge,
509 struct drm_bridge_state *bridge_state,
510 struct drm_crtc_state *crtc_state,
511 struct drm_connector_state *conn_state);
512
513 /**
514 * @atomic_reset:
515 *
516 * Reset the bridge to a predefined state (or retrieve its current
517 * state) and return a &drm_bridge_state object matching this state.
518 * This function is called at attach time.
519 *
520 * The atomic_reset hook is mandatory if the bridge implements any of
521 * the atomic hooks, and should be left unassigned otherwise. For
522 * bridges that don't subclass &drm_bridge_state, the
523 * drm_atomic_helper_bridge_reset() helper function shall be used to
524 * implement this hook.
525 *
526 * Note that the atomic_reset() semantics is not exactly matching the
527 * reset() semantics found on other components (connector, plane, ...).
528 *
529 * 1. The reset operation happens when the bridge is attached, not when
530 * drm_mode_config_reset() is called
531 * 2. It's meant to be used exclusively on bridges that have been
532 * converted to the ATOMIC API
533 *
534 * RETURNS:
535 * A valid drm_bridge_state object in case of success, an ERR_PTR()
536 * giving the reason of the failure otherwise.
537 */
538 struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
539
540 /**
541 * @detect:
542 *
543 * Check if anything is attached to the bridge output.
544 *
545 * This callback is optional, if not implemented the bridge will be
546 * considered as always having a component attached to its output.
547 * Bridges that implement this callback shall set the
548 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
549 *
550 * RETURNS:
551 *
552 * drm_connector_status indicating the bridge output status.
553 */
554 enum drm_connector_status (*detect)(struct drm_bridge *bridge);
555
556 /**
557 * @get_modes:
558 *
559 * Fill all modes currently valid for the sink into the &drm_connector
560 * with drm_mode_probed_add().
561 *
562 * The @get_modes callback is mostly intended to support non-probeable
563 * displays such as many fixed panels. Bridges that support reading
564 * EDID shall leave @get_modes unimplemented and implement the
565 * &drm_bridge_funcs->get_edid callback instead.
566 *
567 * This callback is optional. Bridges that implement it shall set the
568 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
569 *
570 * The connector parameter shall be used for the sole purpose of
571 * filling modes, and shall not be stored internally by bridge drivers
572 * for future usage.
573 *
574 * RETURNS:
575 *
576 * The number of modes added by calling drm_mode_probed_add().
577 */
578 int (*get_modes)(struct drm_bridge *bridge,
579 struct drm_connector *connector);
580
581 /**
582 * @get_edid:
583 *
584 * Read and parse the EDID data of the connected display.
585 *
586 * The @get_edid callback is the preferred way of reporting mode
587 * information for a display connected to the bridge output. Bridges
588 * that support reading EDID shall implement this callback and leave
589 * the @get_modes callback unimplemented.
590 *
591 * The caller of this operation shall first verify the output
592 * connection status and refrain from reading EDID from a disconnected
593 * output.
594 *
595 * This callback is optional. Bridges that implement it shall set the
596 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
597 *
598 * The connector parameter shall be used for the sole purpose of EDID
599 * retrieval and parsing, and shall not be stored internally by bridge
600 * drivers for future usage.
601 *
602 * RETURNS:
603 *
604 * An edid structure newly allocated with kmalloc() (or similar) on
605 * success, or NULL otherwise. The caller is responsible for freeing
606 * the returned edid structure with kfree().
607 */
608 struct edid *(*get_edid)(struct drm_bridge *bridge,
609 struct drm_connector *connector);
610
611 /**
612 * @hpd_notify:
613 *
614 * Notify the bridge of hot plug detection.
615 *
616 * This callback is optional, it may be implemented by bridges that
617 * need to be notified of display connection or disconnection for
618 * internal reasons. One use case is to reset the internal state of CEC
619 * controllers for HDMI bridges.
620 */
621 void (*hpd_notify)(struct drm_bridge *bridge,
622 enum drm_connector_status status);
623
624 /**
625 * @hpd_enable:
626 *
627 * Enable hot plug detection. From now on the bridge shall call
628 * drm_bridge_hpd_notify() each time a change is detected in the output
629 * connection status, until hot plug detection gets disabled with
630 * @hpd_disable.
631 *
632 * This callback is optional and shall only be implemented by bridges
633 * that support hot-plug notification without polling. Bridges that
634 * implement it shall also implement the @hpd_disable callback and set
635 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
636 */
637 void (*hpd_enable)(struct drm_bridge *bridge);
638
639 /**
640 * @hpd_disable:
641 *
642 * Disable hot plug detection. Once this function returns the bridge
643 * shall not call drm_bridge_hpd_notify() when a change in the output
644 * connection status occurs.
645 *
646 * This callback is optional and shall only be implemented by bridges
647 * that support hot-plug notification without polling. Bridges that
648 * implement it shall also implement the @hpd_enable callback and set
649 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
650 */
651 void (*hpd_disable)(struct drm_bridge *bridge);
652
653 /**
654 * @debugfs_init:
655 *
656 * Allows bridges to create bridge-specific debugfs files.
657 */
658 void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);
659};
660
661/**
662 * struct drm_bridge_timings - timing information for the bridge
663 */
664struct drm_bridge_timings {
665 /**
666 * @input_bus_flags:
667 *
668 * Tells what additional settings for the pixel data on the bus
669 * this bridge requires (like pixel signal polarity). See also
670 * &drm_display_info->bus_flags.
671 */
672 u32 input_bus_flags;
673 /**
674 * @setup_time_ps:
675 *
676 * Defines the time in picoseconds the input data lines must be
677 * stable before the clock edge.
678 */
679 u32 setup_time_ps;
680 /**
681 * @hold_time_ps:
682 *
683 * Defines the time in picoseconds taken for the bridge to sample the
684 * input signal after the clock edge.
685 */
686 u32 hold_time_ps;
687 /**
688 * @dual_link:
689 *
690 * True if the bus operates in dual-link mode. The exact meaning is
691 * dependent on the bus type. For LVDS buses, this indicates that even-
692 * and odd-numbered pixels are received on separate links.
693 */
694 bool dual_link;
695};
696
697/**
698 * enum drm_bridge_ops - Bitmask of operations supported by the bridge
699 */
700enum drm_bridge_ops {
701 /**
702 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
703 * its output. Bridges that set this flag shall implement the
704 * &drm_bridge_funcs->detect callback.
705 */
706 DRM_BRIDGE_OP_DETECT = BIT(0),
707 /**
708 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
709 * connected to its output. Bridges that set this flag shall implement
710 * the &drm_bridge_funcs->get_edid callback.
711 */
712 DRM_BRIDGE_OP_EDID = BIT(1),
713 /**
714 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
715 * without requiring polling. Bridges that set this flag shall
716 * implement the &drm_bridge_funcs->hpd_enable and
717 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
718 * and disabling hot-plug detection dynamically.
719 */
720 DRM_BRIDGE_OP_HPD = BIT(2),
721 /**
722 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
723 * by the display at its output. This does not include reading EDID
724 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
725 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
726 */
727 DRM_BRIDGE_OP_MODES = BIT(3),
728};
729
730/**
731 * struct drm_bridge - central DRM bridge control structure
732 */
733struct drm_bridge {
734 /** @base: inherit from &drm_private_object */
735 struct drm_private_obj base;
736 /** @dev: DRM device this bridge belongs to */
737 struct drm_device *dev;
738 /** @encoder: encoder to which this bridge is connected */
739 struct drm_encoder *encoder;
740 /** @chain_node: used to form a bridge chain */
741 struct list_head chain_node;
742#ifdef CONFIG_OF
743 /** @of_node: device node pointer to the bridge */
744 struct device_node *of_node;
745#endif
746 /** @list: to keep track of all added bridges */
747 struct list_head list;
748 /**
749 * @timings:
750 *
751 * the timing specification for the bridge, if any (may be NULL)
752 */
753 const struct drm_bridge_timings *timings;
754 /** @funcs: control functions */
755 const struct drm_bridge_funcs *funcs;
756 /** @driver_private: pointer to the bridge driver's internal context */
757 void *driver_private;
758 /** @ops: bitmask of operations supported by the bridge */
759 enum drm_bridge_ops ops;
760 /**
761 * @type: Type of the connection at the bridge output
762 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
763 * identifies the type of connected display.
764 */
765 int type;
766 /**
767 * @interlace_allowed: Indicate that the bridge can handle interlaced
768 * modes.
769 */
770 bool interlace_allowed;
771 /**
772 * @ddc: Associated I2C adapter for DDC access, if any.
773 */
774 struct i2c_adapter *ddc;
775 /** private: */
776 /**
777 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
778 */
779 struct mutex hpd_mutex;
780 /**
781 * @hpd_cb: Hot plug detection callback, registered with
782 * drm_bridge_hpd_enable().
783 */
784 void (*hpd_cb)(void *data, enum drm_connector_status status);
785 /**
786 * @hpd_data: Private data passed to the Hot plug detection callback
787 * @hpd_cb.
788 */
789 void *hpd_data;
790};
791
792static inline struct drm_bridge *
793drm_priv_to_bridge(struct drm_private_obj *priv)
794{
795 return container_of(priv, struct drm_bridge, base);
796}
797
798void drm_bridge_add(struct drm_bridge *bridge);
799int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
800void drm_bridge_remove(struct drm_bridge *bridge);
801int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
802 struct drm_bridge *previous,
803 enum drm_bridge_attach_flags flags);
804
805#ifdef CONFIG_OF
806struct drm_bridge *of_drm_find_bridge(struct device_node *np);
807#else
808static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
809{
810 return NULL;
811}
812#endif
813
814/**
815 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
816 * @bridge: bridge object
817 *
818 * RETURNS:
819 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
820 */
821static inline struct drm_bridge *
822drm_bridge_get_next_bridge(struct drm_bridge *bridge)
823{
824 if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
825 return NULL;
826
827 return list_next_entry(bridge, chain_node);
828}
829
830/**
831 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
832 * @bridge: bridge object
833 *
834 * RETURNS:
835 * the previous bridge in the chain, or NULL if @bridge is the first.
836 */
837static inline struct drm_bridge *
838drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
839{
840 if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
841 return NULL;
842
843 return list_prev_entry(bridge, chain_node);
844}
845
846/**
847 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
848 * @encoder: encoder object
849 *
850 * RETURNS:
851 * the first bridge in the chain, or NULL if @encoder has no bridge attached
852 * to it.
853 */
854static inline struct drm_bridge *
855drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
856{
857 return list_first_entry_or_null(&encoder->bridge_chain,
858 struct drm_bridge, chain_node);
859}
860
861/**
862 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
863 * @encoder: the encoder to iterate bridges on
864 * @bridge: a bridge pointer updated to point to the current bridge at each
865 * iteration
866 *
867 * Iterate over all bridges present in the bridge chain attached to @encoder.
868 */
869#define drm_for_each_bridge_in_chain(encoder, bridge) \
870 list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
871
872bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
873 const struct drm_display_mode *mode,
874 struct drm_display_mode *adjusted_mode);
875enum drm_mode_status
876drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
877 const struct drm_display_info *info,
878 const struct drm_display_mode *mode);
879void drm_bridge_chain_disable(struct drm_bridge *bridge);
880void drm_bridge_chain_post_disable(struct drm_bridge *bridge);
881void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
882 const struct drm_display_mode *mode,
883 const struct drm_display_mode *adjusted_mode);
884void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
885void drm_bridge_chain_enable(struct drm_bridge *bridge);
886
887int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
888 struct drm_crtc_state *crtc_state,
889 struct drm_connector_state *conn_state);
890void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
891 struct drm_atomic_state *state);
892void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
893 struct drm_atomic_state *state);
894void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
895 struct drm_atomic_state *state);
896void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
897 struct drm_atomic_state *state);
898
899u32 *
900drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
901 struct drm_bridge_state *bridge_state,
902 struct drm_crtc_state *crtc_state,
903 struct drm_connector_state *conn_state,
904 u32 output_fmt,
905 unsigned int *num_input_fmts);
906
907enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
908int drm_bridge_get_modes(struct drm_bridge *bridge,
909 struct drm_connector *connector);
910struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
911 struct drm_connector *connector);
912void drm_bridge_hpd_enable(struct drm_bridge *bridge,
913 void (*cb)(void *data,
914 enum drm_connector_status status),
915 void *data);
916void drm_bridge_hpd_disable(struct drm_bridge *bridge);
917void drm_bridge_hpd_notify(struct drm_bridge *bridge,
918 enum drm_connector_status status);
919
920#ifdef CONFIG_DRM_PANEL_BRIDGE
921bool drm_bridge_is_panel(const struct drm_bridge *bridge);
922struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
923struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
924 u32 connector_type);
925void drm_panel_bridge_remove(struct drm_bridge *bridge);
926int drm_panel_bridge_set_orientation(struct drm_connector *connector,
927 struct drm_bridge *bridge);
928struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
929 struct drm_panel *panel);
930struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
931 struct drm_panel *panel,
932 u32 connector_type);
933struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
934 struct drm_panel *panel);
935struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
936#else
937static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
938{
939 return false;
940}
941
942static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,
943 struct drm_bridge *bridge)
944{
945 return -EINVAL;
946}
947#endif
948
949#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
950struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
951 u32 port, u32 endpoint);
952struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
953 u32 port, u32 endpoint);
954#else
955static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
956 struct device_node *node,
957 u32 port,
958 u32 endpoint)
959{
960 return ERR_PTR(-ENODEV);
961}
962
963static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
964 struct device_node *node,
965 u32 port,
966 u32 endpoint)
967{
968 return ERR_PTR(-ENODEV);
969}
970#endif
971
972#endif
1/*
2 * Copyright (c) 2016 Intel Corporation
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#ifndef __DRM_BRIDGE_H__
24#define __DRM_BRIDGE_H__
25
26#include <linux/ctype.h>
27#include <linux/list.h>
28#include <linux/mutex.h>
29
30#include <drm/drm_atomic.h>
31#include <drm/drm_encoder.h>
32#include <drm/drm_mode_object.h>
33#include <drm/drm_modes.h>
34
35struct device_node;
36
37struct drm_bridge;
38struct drm_bridge_timings;
39struct drm_connector;
40struct drm_display_info;
41struct drm_minor;
42struct drm_panel;
43struct edid;
44struct i2c_adapter;
45
46/**
47 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
48 */
49enum drm_bridge_attach_flags {
50 /**
51 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge
52 * shall not create a drm_connector.
53 */
54 DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),
55};
56
57/**
58 * struct drm_bridge_funcs - drm_bridge control functions
59 */
60struct drm_bridge_funcs {
61 /**
62 * @attach:
63 *
64 * This callback is invoked whenever our bridge is being attached to a
65 * &drm_encoder. The flags argument tunes the behaviour of the attach
66 * operation (see DRM_BRIDGE_ATTACH_*).
67 *
68 * The @attach callback is optional.
69 *
70 * RETURNS:
71 *
72 * Zero on success, error code on failure.
73 */
74 int (*attach)(struct drm_bridge *bridge,
75 enum drm_bridge_attach_flags flags);
76
77 /**
78 * @detach:
79 *
80 * This callback is invoked whenever our bridge is being detached from a
81 * &drm_encoder.
82 *
83 * The @detach callback is optional.
84 */
85 void (*detach)(struct drm_bridge *bridge);
86
87 /**
88 * @mode_valid:
89 *
90 * This callback is used to check if a specific mode is valid in this
91 * bridge. This should be implemented if the bridge has some sort of
92 * restriction in the modes it can display. For example, a given bridge
93 * may be responsible to set a clock value. If the clock can not
94 * produce all the values for the available modes then this callback
95 * can be used to restrict the number of modes to only the ones that
96 * can be displayed.
97 *
98 * This hook is used by the probe helpers to filter the mode list in
99 * drm_helper_probe_single_connector_modes(), and it is used by the
100 * atomic helpers to validate modes supplied by userspace in
101 * drm_atomic_helper_check_modeset().
102 *
103 * The @mode_valid callback is optional.
104 *
105 * NOTE:
106 *
107 * Since this function is both called from the check phase of an atomic
108 * commit, and the mode validation in the probe paths it is not allowed
109 * to look at anything else but the passed-in mode, and validate it
110 * against configuration-invariant hardward constraints. Any further
111 * limits which depend upon the configuration can only be checked in
112 * @mode_fixup.
113 *
114 * RETURNS:
115 *
116 * drm_mode_status Enum
117 */
118 enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
119 const struct drm_display_info *info,
120 const struct drm_display_mode *mode);
121
122 /**
123 * @mode_fixup:
124 *
125 * This callback is used to validate and adjust a mode. The parameter
126 * mode is the display mode that should be fed to the next element in
127 * the display chain, either the final &drm_connector or the next
128 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
129 * requires. It can be modified by this callback and does not need to
130 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
131 *
132 * This is the only hook that allows a bridge to reject a modeset. If
133 * this function passes all other callbacks must succeed for this
134 * configuration.
135 *
136 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
137 * is not called when &drm_bridge_funcs.atomic_check() is implemented,
138 * so only one of them should be provided.
139 *
140 * NOTE:
141 *
142 * This function is called in the check phase of atomic modesets, which
143 * can be aborted for any reason (including on userspace's request to
144 * just check whether a configuration would be possible). Drivers MUST
145 * NOT touch any persistent state (hardware or software) or data
146 * structures except the passed in @state parameter.
147 *
148 * Also beware that userspace can request its own custom modes, neither
149 * core nor helpers filter modes to the list of probe modes reported by
150 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
151 * that modes are filtered consistently put any bridge constraints and
152 * limits checks into @mode_valid.
153 *
154 * RETURNS:
155 *
156 * True if an acceptable configuration is possible, false if the modeset
157 * operation should be rejected.
158 */
159 bool (*mode_fixup)(struct drm_bridge *bridge,
160 const struct drm_display_mode *mode,
161 struct drm_display_mode *adjusted_mode);
162 /**
163 * @disable:
164 *
165 * This callback should disable the bridge. It is called right before
166 * the preceding element in the display pipe is disabled. If the
167 * preceding element is a bridge this means it's called before that
168 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
169 * it's called right before the &drm_encoder_helper_funcs.disable,
170 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
171 * hook.
172 *
173 * The bridge can assume that the display pipe (i.e. clocks and timing
174 * signals) feeding it is still running when this callback is called.
175 *
176 * The @disable callback is optional.
177 *
178 * NOTE:
179 *
180 * This is deprecated, do not use!
181 * New drivers shall use &drm_bridge_funcs.atomic_disable.
182 */
183 void (*disable)(struct drm_bridge *bridge);
184
185 /**
186 * @post_disable:
187 *
188 * This callback should disable the bridge. It is called right after the
189 * preceding element in the display pipe is disabled. If the preceding
190 * element is a bridge this means it's called after that bridge's
191 * @post_disable function. If the preceding element is a &drm_encoder
192 * it's called right after the encoder's
193 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
194 * or &drm_encoder_helper_funcs.dpms hook.
195 *
196 * The bridge must assume that the display pipe (i.e. clocks and timing
197 * signals) feeding it is no longer running when this callback is
198 * called.
199 *
200 * The @post_disable callback is optional.
201 *
202 * NOTE:
203 *
204 * This is deprecated, do not use!
205 * New drivers shall use &drm_bridge_funcs.atomic_post_disable.
206 */
207 void (*post_disable)(struct drm_bridge *bridge);
208
209 /**
210 * @mode_set:
211 *
212 * This callback should set the given mode on the bridge. It is called
213 * after the @mode_set callback for the preceding element in the display
214 * pipeline has been called already. If the bridge is the first element
215 * then this would be &drm_encoder_helper_funcs.mode_set. The display
216 * pipe (i.e. clocks and timing signals) is off when this function is
217 * called.
218 *
219 * The adjusted_mode parameter is the mode output by the CRTC for the
220 * first bridge in the chain. It can be different from the mode
221 * parameter that contains the desired mode for the connector at the end
222 * of the bridges chain, for instance when the first bridge in the chain
223 * performs scaling. The adjusted mode is mostly useful for the first
224 * bridge in the chain and is likely irrelevant for the other bridges.
225 *
226 * For atomic drivers the adjusted_mode is the mode stored in
227 * &drm_crtc_state.adjusted_mode.
228 *
229 * NOTE:
230 *
231 * This is deprecated, do not use!
232 * New drivers shall set their mode in the
233 * &drm_bridge_funcs.atomic_enable operation.
234 */
235 void (*mode_set)(struct drm_bridge *bridge,
236 const struct drm_display_mode *mode,
237 const struct drm_display_mode *adjusted_mode);
238 /**
239 * @pre_enable:
240 *
241 * This callback should enable the bridge. It is called right before
242 * the preceding element in the display pipe is enabled. If the
243 * preceding element is a bridge this means it's called before that
244 * bridge's @pre_enable function. If the preceding element is a
245 * &drm_encoder it's called right before the encoder's
246 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
247 * &drm_encoder_helper_funcs.dpms hook.
248 *
249 * The display pipe (i.e. clocks and timing signals) feeding this bridge
250 * will not yet be running when this callback is called. The bridge must
251 * not enable the display link feeding the next bridge in the chain (if
252 * there is one) when this callback is called.
253 *
254 * The @pre_enable callback is optional.
255 *
256 * NOTE:
257 *
258 * This is deprecated, do not use!
259 * New drivers shall use &drm_bridge_funcs.atomic_pre_enable.
260 */
261 void (*pre_enable)(struct drm_bridge *bridge);
262
263 /**
264 * @enable:
265 *
266 * This callback should enable the bridge. It is called right after
267 * the preceding element in the display pipe is enabled. If the
268 * preceding element is a bridge this means it's called after that
269 * bridge's @enable function. If the preceding element is a
270 * &drm_encoder it's called right after the encoder's
271 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
272 * &drm_encoder_helper_funcs.dpms hook.
273 *
274 * The bridge can assume that the display pipe (i.e. clocks and timing
275 * signals) feeding it is running when this callback is called. This
276 * callback must enable the display link feeding the next bridge in the
277 * chain if there is one.
278 *
279 * The @enable callback is optional.
280 *
281 * NOTE:
282 *
283 * This is deprecated, do not use!
284 * New drivers shall use &drm_bridge_funcs.atomic_enable.
285 */
286 void (*enable)(struct drm_bridge *bridge);
287
288 /**
289 * @atomic_pre_enable:
290 *
291 * This callback should enable the bridge. It is called right before
292 * the preceding element in the display pipe is enabled. If the
293 * preceding element is a bridge this means it's called before that
294 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
295 * element is a &drm_encoder it's called right before the encoder's
296 * &drm_encoder_helper_funcs.atomic_enable hook.
297 *
298 * The display pipe (i.e. clocks and timing signals) feeding this bridge
299 * will not yet be running when this callback is called. The bridge must
300 * not enable the display link feeding the next bridge in the chain (if
301 * there is one) when this callback is called.
302 *
303 * The @atomic_pre_enable callback is optional.
304 */
305 void (*atomic_pre_enable)(struct drm_bridge *bridge,
306 struct drm_bridge_state *old_bridge_state);
307
308 /**
309 * @atomic_enable:
310 *
311 * This callback should enable the bridge. It is called right after
312 * the preceding element in the display pipe is enabled. If the
313 * preceding element is a bridge this means it's called after that
314 * bridge's @atomic_enable or @enable function. If the preceding element
315 * is a &drm_encoder it's called right after the encoder's
316 * &drm_encoder_helper_funcs.atomic_enable hook.
317 *
318 * The bridge can assume that the display pipe (i.e. clocks and timing
319 * signals) feeding it is running when this callback is called. This
320 * callback must enable the display link feeding the next bridge in the
321 * chain if there is one.
322 *
323 * The @atomic_enable callback is optional.
324 */
325 void (*atomic_enable)(struct drm_bridge *bridge,
326 struct drm_bridge_state *old_bridge_state);
327 /**
328 * @atomic_disable:
329 *
330 * This callback should disable the bridge. It is called right before
331 * the preceding element in the display pipe is disabled. If the
332 * preceding element is a bridge this means it's called before that
333 * bridge's @atomic_disable or @disable vfunc. If the preceding element
334 * is a &drm_encoder it's called right before the
335 * &drm_encoder_helper_funcs.atomic_disable hook.
336 *
337 * The bridge can assume that the display pipe (i.e. clocks and timing
338 * signals) feeding it is still running when this callback is called.
339 *
340 * The @atomic_disable callback is optional.
341 */
342 void (*atomic_disable)(struct drm_bridge *bridge,
343 struct drm_bridge_state *old_bridge_state);
344
345 /**
346 * @atomic_post_disable:
347 *
348 * This callback should disable the bridge. It is called right after the
349 * preceding element in the display pipe is disabled. If the preceding
350 * element is a bridge this means it's called after that bridge's
351 * @atomic_post_disable or @post_disable function. If the preceding
352 * element is a &drm_encoder it's called right after the encoder's
353 * &drm_encoder_helper_funcs.atomic_disable hook.
354 *
355 * The bridge must assume that the display pipe (i.e. clocks and timing
356 * signals) feeding it is no longer running when this callback is
357 * called.
358 *
359 * The @atomic_post_disable callback is optional.
360 */
361 void (*atomic_post_disable)(struct drm_bridge *bridge,
362 struct drm_bridge_state *old_bridge_state);
363
364 /**
365 * @atomic_duplicate_state:
366 *
367 * Duplicate the current bridge state object (which is guaranteed to be
368 * non-NULL).
369 *
370 * The atomic_duplicate_state hook is mandatory if the bridge
371 * implements any of the atomic hooks, and should be left unassigned
372 * otherwise. For bridges that don't subclass &drm_bridge_state, the
373 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
374 * used to implement this hook.
375 *
376 * RETURNS:
377 * A valid drm_bridge_state object or NULL if the allocation fails.
378 */
379 struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
380
381 /**
382 * @atomic_destroy_state:
383 *
384 * Destroy a bridge state object previously allocated by
385 * &drm_bridge_funcs.atomic_duplicate_state().
386 *
387 * The atomic_destroy_state hook is mandatory if the bridge implements
388 * any of the atomic hooks, and should be left unassigned otherwise.
389 * For bridges that don't subclass &drm_bridge_state, the
390 * drm_atomic_helper_bridge_destroy_state() helper function shall be
391 * used to implement this hook.
392 */
393 void (*atomic_destroy_state)(struct drm_bridge *bridge,
394 struct drm_bridge_state *state);
395
396 /**
397 * @atomic_get_output_bus_fmts:
398 *
399 * Return the supported bus formats on the output end of a bridge.
400 * The returned array must be allocated with kmalloc() and will be
401 * freed by the caller. If the allocation fails, NULL should be
402 * returned. num_output_fmts must be set to the returned array size.
403 * Formats listed in the returned array should be listed in decreasing
404 * preference order (the core will try all formats until it finds one
405 * that works).
406 *
407 * This method is only called on the last element of the bridge chain
408 * as part of the bus format negotiation process that happens in
409 * &drm_atomic_bridge_chain_select_bus_fmts().
410 * This method is optional. When not implemented, the core will
411 * fall back to &drm_connector.display_info.bus_formats[0] if
412 * &drm_connector.display_info.num_bus_formats > 0,
413 * or to MEDIA_BUS_FMT_FIXED otherwise.
414 */
415 u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
416 struct drm_bridge_state *bridge_state,
417 struct drm_crtc_state *crtc_state,
418 struct drm_connector_state *conn_state,
419 unsigned int *num_output_fmts);
420
421 /**
422 * @atomic_get_input_bus_fmts:
423 *
424 * Return the supported bus formats on the input end of a bridge for
425 * a specific output bus format.
426 *
427 * The returned array must be allocated with kmalloc() and will be
428 * freed by the caller. If the allocation fails, NULL should be
429 * returned. num_input_fmts must be set to the returned array size.
430 * Formats listed in the returned array should be listed in decreasing
431 * preference order (the core will try all formats until it finds one
432 * that works). When the format is not supported NULL should be
433 * returned and num_input_fmts should be set to 0.
434 *
435 * This method is called on all elements of the bridge chain as part of
436 * the bus format negotiation process that happens in
437 * drm_atomic_bridge_chain_select_bus_fmts().
438 * This method is optional. When not implemented, the core will bypass
439 * bus format negotiation on this element of the bridge without
440 * failing, and the previous element in the chain will be passed
441 * MEDIA_BUS_FMT_FIXED as its output bus format.
442 *
443 * Bridge drivers that need to support being linked to bridges that are
444 * not supporting bus format negotiation should handle the
445 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
446 * sensible default value or extracting this information from somewhere
447 * else (FW property, &drm_display_mode, &drm_display_info, ...)
448 *
449 * Note: Even if input format selection on the first bridge has no
450 * impact on the negotiation process (bus format negotiation stops once
451 * we reach the first element of the chain), drivers are expected to
452 * return accurate input formats as the input format may be used to
453 * configure the CRTC output appropriately.
454 */
455 u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
456 struct drm_bridge_state *bridge_state,
457 struct drm_crtc_state *crtc_state,
458 struct drm_connector_state *conn_state,
459 u32 output_fmt,
460 unsigned int *num_input_fmts);
461
462 /**
463 * @atomic_check:
464 *
465 * This method is responsible for checking bridge state correctness.
466 * It can also check the state of the surrounding components in chain
467 * to make sure the whole pipeline can work properly.
468 *
469 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
470 * order (from the last to the first bridge).
471 *
472 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
473 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
474 * one of them should be provided.
475 *
476 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
477 * &drm_bridge_state.output_bus_cfg.flags it should happen in
478 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
479 * field is set to the next bridge
480 * &drm_bridge_state.input_bus_cfg.flags value or
481 * &drm_connector.display_info.bus_flags if the bridge is the last
482 * element in the chain.
483 *
484 * RETURNS:
485 * zero if the check passed, a negative error code otherwise.
486 */
487 int (*atomic_check)(struct drm_bridge *bridge,
488 struct drm_bridge_state *bridge_state,
489 struct drm_crtc_state *crtc_state,
490 struct drm_connector_state *conn_state);
491
492 /**
493 * @atomic_reset:
494 *
495 * Reset the bridge to a predefined state (or retrieve its current
496 * state) and return a &drm_bridge_state object matching this state.
497 * This function is called at attach time.
498 *
499 * The atomic_reset hook is mandatory if the bridge implements any of
500 * the atomic hooks, and should be left unassigned otherwise. For
501 * bridges that don't subclass &drm_bridge_state, the
502 * drm_atomic_helper_bridge_reset() helper function shall be used to
503 * implement this hook.
504 *
505 * Note that the atomic_reset() semantics is not exactly matching the
506 * reset() semantics found on other components (connector, plane, ...).
507 *
508 * 1. The reset operation happens when the bridge is attached, not when
509 * drm_mode_config_reset() is called
510 * 2. It's meant to be used exclusively on bridges that have been
511 * converted to the ATOMIC API
512 *
513 * RETURNS:
514 * A valid drm_bridge_state object in case of success, an ERR_PTR()
515 * giving the reason of the failure otherwise.
516 */
517 struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
518
519 /**
520 * @detect:
521 *
522 * Check if anything is attached to the bridge output.
523 *
524 * This callback is optional, if not implemented the bridge will be
525 * considered as always having a component attached to its output.
526 * Bridges that implement this callback shall set the
527 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
528 *
529 * RETURNS:
530 *
531 * drm_connector_status indicating the bridge output status.
532 */
533 enum drm_connector_status (*detect)(struct drm_bridge *bridge);
534
535 /**
536 * @get_modes:
537 *
538 * Fill all modes currently valid for the sink into the &drm_connector
539 * with drm_mode_probed_add().
540 *
541 * The @get_modes callback is mostly intended to support non-probeable
542 * displays such as many fixed panels. Bridges that support reading
543 * EDID shall leave @get_modes unimplemented and implement the
544 * &drm_bridge_funcs->get_edid callback instead.
545 *
546 * This callback is optional. Bridges that implement it shall set the
547 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
548 *
549 * The connector parameter shall be used for the sole purpose of
550 * filling modes, and shall not be stored internally by bridge drivers
551 * for future usage.
552 *
553 * RETURNS:
554 *
555 * The number of modes added by calling drm_mode_probed_add().
556 */
557 int (*get_modes)(struct drm_bridge *bridge,
558 struct drm_connector *connector);
559
560 /**
561 * @get_edid:
562 *
563 * Read and parse the EDID data of the connected display.
564 *
565 * The @get_edid callback is the preferred way of reporting mode
566 * information for a display connected to the bridge output. Bridges
567 * that support reading EDID shall implement this callback and leave
568 * the @get_modes callback unimplemented.
569 *
570 * The caller of this operation shall first verify the output
571 * connection status and refrain from reading EDID from a disconnected
572 * output.
573 *
574 * This callback is optional. Bridges that implement it shall set the
575 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
576 *
577 * The connector parameter shall be used for the sole purpose of EDID
578 * retrieval and parsing, and shall not be stored internally by bridge
579 * drivers for future usage.
580 *
581 * RETURNS:
582 *
583 * An edid structure newly allocated with kmalloc() (or similar) on
584 * success, or NULL otherwise. The caller is responsible for freeing
585 * the returned edid structure with kfree().
586 */
587 struct edid *(*get_edid)(struct drm_bridge *bridge,
588 struct drm_connector *connector);
589
590 /**
591 * @hpd_notify:
592 *
593 * Notify the bridge of hot plug detection.
594 *
595 * This callback is optional, it may be implemented by bridges that
596 * need to be notified of display connection or disconnection for
597 * internal reasons. One use case is to reset the internal state of CEC
598 * controllers for HDMI bridges.
599 */
600 void (*hpd_notify)(struct drm_bridge *bridge,
601 enum drm_connector_status status);
602
603 /**
604 * @hpd_enable:
605 *
606 * Enable hot plug detection. From now on the bridge shall call
607 * drm_bridge_hpd_notify() each time a change is detected in the output
608 * connection status, until hot plug detection gets disabled with
609 * @hpd_disable.
610 *
611 * This callback is optional and shall only be implemented by bridges
612 * that support hot-plug notification without polling. Bridges that
613 * implement it shall also implement the @hpd_disable callback and set
614 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
615 */
616 void (*hpd_enable)(struct drm_bridge *bridge);
617
618 /**
619 * @hpd_disable:
620 *
621 * Disable hot plug detection. Once this function returns the bridge
622 * shall not call drm_bridge_hpd_notify() when a change in the output
623 * connection status occurs.
624 *
625 * This callback is optional and shall only be implemented by bridges
626 * that support hot-plug notification without polling. Bridges that
627 * implement it shall also implement the @hpd_enable callback and set
628 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
629 */
630 void (*hpd_disable)(struct drm_bridge *bridge);
631
632 /**
633 * @debugfs_init:
634 *
635 * Allows bridges to create bridge-specific debugfs files.
636 */
637 void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);
638};
639
640/**
641 * struct drm_bridge_timings - timing information for the bridge
642 */
643struct drm_bridge_timings {
644 /**
645 * @input_bus_flags:
646 *
647 * Tells what additional settings for the pixel data on the bus
648 * this bridge requires (like pixel signal polarity). See also
649 * &drm_display_info->bus_flags.
650 */
651 u32 input_bus_flags;
652 /**
653 * @setup_time_ps:
654 *
655 * Defines the time in picoseconds the input data lines must be
656 * stable before the clock edge.
657 */
658 u32 setup_time_ps;
659 /**
660 * @hold_time_ps:
661 *
662 * Defines the time in picoseconds taken for the bridge to sample the
663 * input signal after the clock edge.
664 */
665 u32 hold_time_ps;
666 /**
667 * @dual_link:
668 *
669 * True if the bus operates in dual-link mode. The exact meaning is
670 * dependent on the bus type. For LVDS buses, this indicates that even-
671 * and odd-numbered pixels are received on separate links.
672 */
673 bool dual_link;
674};
675
676/**
677 * enum drm_bridge_ops - Bitmask of operations supported by the bridge
678 */
679enum drm_bridge_ops {
680 /**
681 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
682 * its output. Bridges that set this flag shall implement the
683 * &drm_bridge_funcs->detect callback.
684 */
685 DRM_BRIDGE_OP_DETECT = BIT(0),
686 /**
687 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
688 * connected to its output. Bridges that set this flag shall implement
689 * the &drm_bridge_funcs->get_edid callback.
690 */
691 DRM_BRIDGE_OP_EDID = BIT(1),
692 /**
693 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
694 * without requiring polling. Bridges that set this flag shall
695 * implement the &drm_bridge_funcs->hpd_enable and
696 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
697 * and disabling hot-plug detection dynamically.
698 */
699 DRM_BRIDGE_OP_HPD = BIT(2),
700 /**
701 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
702 * by the display at its output. This does not include reading EDID
703 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
704 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
705 */
706 DRM_BRIDGE_OP_MODES = BIT(3),
707};
708
709/**
710 * struct drm_bridge - central DRM bridge control structure
711 */
712struct drm_bridge {
713 /** @base: inherit from &drm_private_object */
714 struct drm_private_obj base;
715 /** @dev: DRM device this bridge belongs to */
716 struct drm_device *dev;
717 /** @encoder: encoder to which this bridge is connected */
718 struct drm_encoder *encoder;
719 /** @chain_node: used to form a bridge chain */
720 struct list_head chain_node;
721 /** @of_node: device node pointer to the bridge */
722 struct device_node *of_node;
723 /** @list: to keep track of all added bridges */
724 struct list_head list;
725 /**
726 * @timings:
727 *
728 * the timing specification for the bridge, if any (may be NULL)
729 */
730 const struct drm_bridge_timings *timings;
731 /** @funcs: control functions */
732 const struct drm_bridge_funcs *funcs;
733 /** @driver_private: pointer to the bridge driver's internal context */
734 void *driver_private;
735 /** @ops: bitmask of operations supported by the bridge */
736 enum drm_bridge_ops ops;
737 /**
738 * @type: Type of the connection at the bridge output
739 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
740 * identifies the type of connected display.
741 */
742 int type;
743 /**
744 * @interlace_allowed: Indicate that the bridge can handle interlaced
745 * modes.
746 */
747 bool interlace_allowed;
748 /**
749 * @pre_enable_prev_first: The bridge requires that the prev
750 * bridge @pre_enable function is called before its @pre_enable,
751 * and conversely for post_disable. This is most frequently a
752 * requirement for DSI devices which need the host to be initialised
753 * before the peripheral.
754 */
755 bool pre_enable_prev_first;
756 /**
757 * @ddc: Associated I2C adapter for DDC access, if any.
758 */
759 struct i2c_adapter *ddc;
760 /** private: */
761 /**
762 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
763 */
764 struct mutex hpd_mutex;
765 /**
766 * @hpd_cb: Hot plug detection callback, registered with
767 * drm_bridge_hpd_enable().
768 */
769 void (*hpd_cb)(void *data, enum drm_connector_status status);
770 /**
771 * @hpd_data: Private data passed to the Hot plug detection callback
772 * @hpd_cb.
773 */
774 void *hpd_data;
775};
776
777static inline struct drm_bridge *
778drm_priv_to_bridge(struct drm_private_obj *priv)
779{
780 return container_of(priv, struct drm_bridge, base);
781}
782
783void drm_bridge_add(struct drm_bridge *bridge);
784int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
785void drm_bridge_remove(struct drm_bridge *bridge);
786int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
787 struct drm_bridge *previous,
788 enum drm_bridge_attach_flags flags);
789
790#ifdef CONFIG_OF
791struct drm_bridge *of_drm_find_bridge(struct device_node *np);
792#else
793static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
794{
795 return NULL;
796}
797#endif
798
799/**
800 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
801 * @bridge: bridge object
802 *
803 * RETURNS:
804 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
805 */
806static inline struct drm_bridge *
807drm_bridge_get_next_bridge(struct drm_bridge *bridge)
808{
809 if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
810 return NULL;
811
812 return list_next_entry(bridge, chain_node);
813}
814
815/**
816 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
817 * @bridge: bridge object
818 *
819 * RETURNS:
820 * the previous bridge in the chain, or NULL if @bridge is the first.
821 */
822static inline struct drm_bridge *
823drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
824{
825 if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
826 return NULL;
827
828 return list_prev_entry(bridge, chain_node);
829}
830
831/**
832 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
833 * @encoder: encoder object
834 *
835 * RETURNS:
836 * the first bridge in the chain, or NULL if @encoder has no bridge attached
837 * to it.
838 */
839static inline struct drm_bridge *
840drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
841{
842 return list_first_entry_or_null(&encoder->bridge_chain,
843 struct drm_bridge, chain_node);
844}
845
846/**
847 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
848 * @encoder: the encoder to iterate bridges on
849 * @bridge: a bridge pointer updated to point to the current bridge at each
850 * iteration
851 *
852 * Iterate over all bridges present in the bridge chain attached to @encoder.
853 */
854#define drm_for_each_bridge_in_chain(encoder, bridge) \
855 list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
856
857bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
858 const struct drm_display_mode *mode,
859 struct drm_display_mode *adjusted_mode);
860enum drm_mode_status
861drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
862 const struct drm_display_info *info,
863 const struct drm_display_mode *mode);
864void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
865 const struct drm_display_mode *mode,
866 const struct drm_display_mode *adjusted_mode);
867
868int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
869 struct drm_crtc_state *crtc_state,
870 struct drm_connector_state *conn_state);
871void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
872 struct drm_atomic_state *state);
873void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
874 struct drm_atomic_state *state);
875void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
876 struct drm_atomic_state *state);
877void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
878 struct drm_atomic_state *state);
879
880u32 *
881drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
882 struct drm_bridge_state *bridge_state,
883 struct drm_crtc_state *crtc_state,
884 struct drm_connector_state *conn_state,
885 u32 output_fmt,
886 unsigned int *num_input_fmts);
887
888enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
889int drm_bridge_get_modes(struct drm_bridge *bridge,
890 struct drm_connector *connector);
891struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
892 struct drm_connector *connector);
893void drm_bridge_hpd_enable(struct drm_bridge *bridge,
894 void (*cb)(void *data,
895 enum drm_connector_status status),
896 void *data);
897void drm_bridge_hpd_disable(struct drm_bridge *bridge);
898void drm_bridge_hpd_notify(struct drm_bridge *bridge,
899 enum drm_connector_status status);
900
901#ifdef CONFIG_DRM_PANEL_BRIDGE
902bool drm_bridge_is_panel(const struct drm_bridge *bridge);
903struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
904struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
905 u32 connector_type);
906void drm_panel_bridge_remove(struct drm_bridge *bridge);
907int drm_panel_bridge_set_orientation(struct drm_connector *connector,
908 struct drm_bridge *bridge);
909struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
910 struct drm_panel *panel);
911struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
912 struct drm_panel *panel,
913 u32 connector_type);
914struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
915 struct drm_panel *panel);
916struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
917#else
918static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
919{
920 return false;
921}
922
923static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,
924 struct drm_bridge *bridge)
925{
926 return -EINVAL;
927}
928#endif
929
930#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
931struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
932 u32 port, u32 endpoint);
933struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
934 u32 port, u32 endpoint);
935#else
936static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
937 struct device_node *node,
938 u32 port,
939 u32 endpoint)
940{
941 return ERR_PTR(-ENODEV);
942}
943
944static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
945 struct device_node *node,
946 u32 port,
947 u32 endpoint)
948{
949 return ERR_PTR(-ENODEV);
950}
951#endif
952
953#endif