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
35 struct drm_bridge;
36 struct drm_bridge_timings;
37 struct drm_connector;
38 struct drm_display_info;
39 struct drm_panel;
40 struct edid;
41 struct i2c_adapter;
42
43 /**
44 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
45 */
46 enum 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 */
57 struct 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 * The @atomic_pre_enable callback is optional.
301 */
302 void (*atomic_pre_enable)(struct drm_bridge *bridge,
303 struct drm_bridge_state *old_bridge_state);
304
305 /**
306 * @atomic_enable:
307 *
308 * This callback should enable the bridge. It is called right after
309 * the preceding element in the display pipe is enabled. If the
310 * preceding element is a bridge this means it's called after that
311 * bridge's @atomic_enable or @enable function. If the preceding element
312 * is a &drm_encoder it's called right after the encoder's
313 * &drm_encoder_helper_funcs.atomic_enable hook.
314 *
315 * The bridge can assume that the display pipe (i.e. clocks and timing
316 * signals) feeding it is running when this callback is called. This
317 * callback must enable the display link feeding the next bridge in the
318 * chain if there is one.
319 *
320 * The @atomic_enable callback is optional.
321 */
322 void (*atomic_enable)(struct drm_bridge *bridge,
323 struct drm_bridge_state *old_bridge_state);
324 /**
325 * @atomic_disable:
326 *
327 * This callback should disable the bridge. It is called right before
328 * the preceding element in the display pipe is disabled. If the
329 * preceding element is a bridge this means it's called before that
330 * bridge's @atomic_disable or @disable vfunc. If the preceding element
331 * is a &drm_encoder it's called right before the
332 * &drm_encoder_helper_funcs.atomic_disable hook.
333 *
334 * The bridge can assume that the display pipe (i.e. clocks and timing
335 * signals) feeding it is still running when this callback is called.
336 *
337 * The @atomic_disable callback is optional.
338 */
339 void (*atomic_disable)(struct drm_bridge *bridge,
340 struct drm_bridge_state *old_bridge_state);
341
342 /**
343 * @atomic_post_disable:
344 *
345 * This callback should disable the bridge. It is called right after the
346 * preceding element in the display pipe is disabled. If the preceding
347 * element is a bridge this means it's called after that bridge's
348 * @atomic_post_disable or @post_disable function. If the preceding
349 * element is a &drm_encoder it's called right after the encoder's
350 * &drm_encoder_helper_funcs.atomic_disable hook.
351 *
352 * The bridge must assume that the display pipe (i.e. clocks and timing
353 * signals) feeding it is no longer running when this callback is
354 * called.
355 *
356 * The @atomic_post_disable callback is optional.
357 */
358 void (*atomic_post_disable)(struct drm_bridge *bridge,
359 struct drm_bridge_state *old_bridge_state);
360
361 /**
362 * @atomic_duplicate_state:
363 *
364 * Duplicate the current bridge state object (which is guaranteed to be
365 * non-NULL).
366 *
367 * The atomic_duplicate_state hook is mandatory if the bridge
368 * implements any of the atomic hooks, and should be left unassigned
369 * otherwise. For bridges that don't subclass &drm_bridge_state, the
370 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
371 * used to implement this hook.
372 *
373 * RETURNS:
374 * A valid drm_bridge_state object or NULL if the allocation fails.
375 */
376 struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
377
378 /**
379 * @atomic_destroy_state:
380 *
381 * Destroy a bridge state object previously allocated by
382 * &drm_bridge_funcs.atomic_duplicate_state().
383 *
384 * The atomic_destroy_state hook is mandatory if the bridge implements
385 * any of the atomic hooks, and should be left unassigned otherwise.
386 * For bridges that don't subclass &drm_bridge_state, the
387 * drm_atomic_helper_bridge_destroy_state() helper function shall be
388 * used to implement this hook.
389 */
390 void (*atomic_destroy_state)(struct drm_bridge *bridge,
391 struct drm_bridge_state *state);
392
393 /**
394 * @atomic_get_output_bus_fmts:
395 *
396 * Return the supported bus formats on the output end of a bridge.
397 * The returned array must be allocated with kmalloc() and will be
398 * freed by the caller. If the allocation fails, NULL should be
399 * returned. num_output_fmts must be set to the returned array size.
400 * Formats listed in the returned array should be listed in decreasing
401 * preference order (the core will try all formats until it finds one
402 * that works).
403 *
404 * This method is only called on the last element of the bridge chain
405 * as part of the bus format negotiation process that happens in
406 * &drm_atomic_bridge_chain_select_bus_fmts().
407 * This method is optional. When not implemented, the core will
408 * fall back to &drm_connector.display_info.bus_formats[0] if
409 * &drm_connector.display_info.num_bus_formats > 0,
410 * or to MEDIA_BUS_FMT_FIXED otherwise.
411 */
412 u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
413 struct drm_bridge_state *bridge_state,
414 struct drm_crtc_state *crtc_state,
415 struct drm_connector_state *conn_state,
416 unsigned int *num_output_fmts);
417
418 /**
419 * @atomic_get_input_bus_fmts:
420 *
421 * Return the supported bus formats on the input end of a bridge for
422 * a specific output bus format.
423 *
424 * The returned array must be allocated with kmalloc() and will be
425 * freed by the caller. If the allocation fails, NULL should be
426 * returned. num_output_fmts must be set to the returned array size.
427 * Formats listed in the returned array should be listed in decreasing
428 * preference order (the core will try all formats until it finds one
429 * that works). When the format is not supported NULL should be
430 * returned and num_output_fmts should be set to 0.
431 *
432 * This method is called on all elements of the bridge chain as part of
433 * the bus format negotiation process that happens in
434 * drm_atomic_bridge_chain_select_bus_fmts().
435 * This method is optional. When not implemented, the core will bypass
436 * bus format negotiation on this element of the bridge without
437 * failing, and the previous element in the chain will be passed
438 * MEDIA_BUS_FMT_FIXED as its output bus format.
439 *
440 * Bridge drivers that need to support being linked to bridges that are
441 * not supporting bus format negotiation should handle the
442 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
443 * sensible default value or extracting this information from somewhere
444 * else (FW property, &drm_display_mode, &drm_display_info, ...)
445 *
446 * Note: Even if input format selection on the first bridge has no
447 * impact on the negotiation process (bus format negotiation stops once
448 * we reach the first element of the chain), drivers are expected to
449 * return accurate input formats as the input format may be used to
450 * configure the CRTC output appropriately.
451 */
452 u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
453 struct drm_bridge_state *bridge_state,
454 struct drm_crtc_state *crtc_state,
455 struct drm_connector_state *conn_state,
456 u32 output_fmt,
457 unsigned int *num_input_fmts);
458
459 /**
460 * @atomic_check:
461 *
462 * This method is responsible for checking bridge state correctness.
463 * It can also check the state of the surrounding components in chain
464 * to make sure the whole pipeline can work properly.
465 *
466 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
467 * order (from the last to the first bridge).
468 *
469 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
470 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
471 * one of them should be provided.
472 *
473 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
474 * &drm_bridge_state.output_bus_cfg.flags it should happen in
475 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
476 * field is set to the next bridge
477 * &drm_bridge_state.input_bus_cfg.flags value or
478 * &drm_connector.display_info.bus_flags if the bridge is the last
479 * element in the chain.
480 *
481 * RETURNS:
482 * zero if the check passed, a negative error code otherwise.
483 */
484 int (*atomic_check)(struct drm_bridge *bridge,
485 struct drm_bridge_state *bridge_state,
486 struct drm_crtc_state *crtc_state,
487 struct drm_connector_state *conn_state);
488
489 /**
490 * @atomic_reset:
491 *
492 * Reset the bridge to a predefined state (or retrieve its current
493 * state) and return a &drm_bridge_state object matching this state.
494 * This function is called at attach time.
495 *
496 * The atomic_reset hook is mandatory if the bridge implements any of
497 * the atomic hooks, and should be left unassigned otherwise. For
498 * bridges that don't subclass &drm_bridge_state, the
499 * drm_atomic_helper_bridge_reset() helper function shall be used to
500 * implement this hook.
501 *
502 * Note that the atomic_reset() semantics is not exactly matching the
503 * reset() semantics found on other components (connector, plane, ...).
504 *
505 * 1. The reset operation happens when the bridge is attached, not when
506 * drm_mode_config_reset() is called
507 * 2. It's meant to be used exclusively on bridges that have been
508 * converted to the ATOMIC API
509 *
510 * RETURNS:
511 * A valid drm_bridge_state object in case of success, an ERR_PTR()
512 * giving the reason of the failure otherwise.
513 */
514 struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
515
516 /**
517 * @detect:
518 *
519 * Check if anything is attached to the bridge output.
520 *
521 * This callback is optional, if not implemented the bridge will be
522 * considered as always having a component attached to its output.
523 * Bridges that implement this callback shall set the
524 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
525 *
526 * RETURNS:
527 *
528 * drm_connector_status indicating the bridge output status.
529 */
530 enum drm_connector_status (*detect)(struct drm_bridge *bridge);
531
532 /**
533 * @get_modes:
534 *
535 * Fill all modes currently valid for the sink into the &drm_connector
536 * with drm_mode_probed_add().
537 *
538 * The @get_modes callback is mostly intended to support non-probeable
539 * displays such as many fixed panels. Bridges that support reading
540 * EDID shall leave @get_modes unimplemented and implement the
541 * &drm_bridge_funcs->get_edid callback instead.
542 *
543 * This callback is optional. Bridges that implement it shall set the
544 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
545 *
546 * The connector parameter shall be used for the sole purpose of
547 * filling modes, and shall not be stored internally by bridge drivers
548 * for future usage.
549 *
550 * RETURNS:
551 *
552 * The number of modes added by calling drm_mode_probed_add().
553 */
554 int (*get_modes)(struct drm_bridge *bridge,
555 struct drm_connector *connector);
556
557 /**
558 * @get_edid:
559 *
560 * Read and parse the EDID data of the connected display.
561 *
562 * The @get_edid callback is the preferred way of reporting mode
563 * information for a display connected to the bridge output. Bridges
564 * that support reading EDID shall implement this callback and leave
565 * the @get_modes callback unimplemented.
566 *
567 * The caller of this operation shall first verify the output
568 * connection status and refrain from reading EDID from a disconnected
569 * output.
570 *
571 * This callback is optional. Bridges that implement it shall set the
572 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
573 *
574 * The connector parameter shall be used for the sole purpose of EDID
575 * retrieval and parsing, and shall not be stored internally by bridge
576 * drivers for future usage.
577 *
578 * RETURNS:
579 *
580 * An edid structure newly allocated with kmalloc() (or similar) on
581 * success, or NULL otherwise. The caller is responsible for freeing
582 * the returned edid structure with kfree().
583 */
584 struct edid *(*get_edid)(struct drm_bridge *bridge,
585 struct drm_connector *connector);
586
587 /**
588 * @hpd_notify:
589 *
590 * Notify the bridge of hot plug detection.
591 *
592 * This callback is optional, it may be implemented by bridges that
593 * need to be notified of display connection or disconnection for
594 * internal reasons. One use case is to reset the internal state of CEC
595 * controllers for HDMI bridges.
596 */
597 void (*hpd_notify)(struct drm_bridge *bridge,
598 enum drm_connector_status status);
599
600 /**
601 * @hpd_enable:
602 *
603 * Enable hot plug detection. From now on the bridge shall call
604 * drm_bridge_hpd_notify() each time a change is detected in the output
605 * connection status, until hot plug detection gets disabled with
606 * @hpd_disable.
607 *
608 * This callback is optional and shall only be implemented by bridges
609 * that support hot-plug notification without polling. Bridges that
610 * implement it shall also implement the @hpd_disable callback and set
611 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
612 */
613 void (*hpd_enable)(struct drm_bridge *bridge);
614
615 /**
616 * @hpd_disable:
617 *
618 * Disable hot plug detection. Once this function returns the bridge
619 * shall not call drm_bridge_hpd_notify() when a change in the output
620 * connection status occurs.
621 *
622 * This callback is optional and shall only be implemented by bridges
623 * that support hot-plug notification without polling. Bridges that
624 * implement it shall also implement the @hpd_enable callback and set
625 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
626 */
627 void (*hpd_disable)(struct drm_bridge *bridge);
628
629 /**
630 * @debugfs_init:
631 *
632 * Allows bridges to create bridge-specific debugfs files.
633 */
634 void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);
635 };
636
637 /**
638 * struct drm_bridge_timings - timing information for the bridge
639 */
640 struct drm_bridge_timings {
641 /**
642 * @input_bus_flags:
643 *
644 * Tells what additional settings for the pixel data on the bus
645 * this bridge requires (like pixel signal polarity). See also
646 * &drm_display_info->bus_flags.
647 */
648 u32 input_bus_flags;
649 /**
650 * @setup_time_ps:
651 *
652 * Defines the time in picoseconds the input data lines must be
653 * stable before the clock edge.
654 */
655 u32 setup_time_ps;
656 /**
657 * @hold_time_ps:
658 *
659 * Defines the time in picoseconds taken for the bridge to sample the
660 * input signal after the clock edge.
661 */
662 u32 hold_time_ps;
663 /**
664 * @dual_link:
665 *
666 * True if the bus operates in dual-link mode. The exact meaning is
667 * dependent on the bus type. For LVDS buses, this indicates that even-
668 * and odd-numbered pixels are received on separate links.
669 */
670 bool dual_link;
671 };
672
673 /**
674 * enum drm_bridge_ops - Bitmask of operations supported by the bridge
675 */
676 enum drm_bridge_ops {
677 /**
678 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
679 * its output. Bridges that set this flag shall implement the
680 * &drm_bridge_funcs->detect callback.
681 */
682 DRM_BRIDGE_OP_DETECT = BIT(0),
683 /**
684 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
685 * connected to its output. Bridges that set this flag shall implement
686 * the &drm_bridge_funcs->get_edid callback.
687 */
688 DRM_BRIDGE_OP_EDID = BIT(1),
689 /**
690 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
691 * without requiring polling. Bridges that set this flag shall
692 * implement the &drm_bridge_funcs->hpd_enable and
693 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
694 * and disabling hot-plug detection dynamically.
695 */
696 DRM_BRIDGE_OP_HPD = BIT(2),
697 /**
698 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
699 * by the display at its output. This does not include reading EDID
700 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
701 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
702 */
703 DRM_BRIDGE_OP_MODES = BIT(3),
704 };
705
706 /**
707 * struct drm_bridge - central DRM bridge control structure
708 */
709 struct drm_bridge {
710 /** @base: inherit from &drm_private_object */
711 struct drm_private_obj base;
712 /** @dev: DRM device this bridge belongs to */
713 struct drm_device *dev;
714 /** @encoder: encoder to which this bridge is connected */
715 struct drm_encoder *encoder;
716 /** @chain_node: used to form a bridge chain */
717 struct list_head chain_node;
718 #ifdef CONFIG_OF
719 /** @of_node: device node pointer to the bridge */
720 struct device_node *of_node;
721 #endif
722 /** @list: to keep track of all added bridges */
723 struct list_head list;
724 /**
725 * @timings:
726 *
727 * the timing specification for the bridge, if any (may be NULL)
728 */
729 const struct drm_bridge_timings *timings;
730 /** @funcs: control functions */
731 const struct drm_bridge_funcs *funcs;
732 /** @driver_private: pointer to the bridge driver's internal context */
733 void *driver_private;
734 /** @ops: bitmask of operations supported by the bridge */
735 enum drm_bridge_ops ops;
736 /**
737 * @type: Type of the connection at the bridge output
738 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
739 * identifies the type of connected display.
740 */
741 int type;
742 /**
743 * @interlace_allowed: Indicate that the bridge can handle interlaced
744 * modes.
745 */
746 bool interlace_allowed;
747 /**
748 * @pre_enable_prev_first: The bridge requires that the prev
749 * bridge @pre_enable function is called before its @pre_enable,
750 * and conversely for post_disable. This is most frequently a
751 * requirement for DSI devices which need the host to be initialised
752 * before the peripheral.
753 */
754 bool pre_enable_prev_first;
755 /**
756 * @ddc: Associated I2C adapter for DDC access, if any.
757 */
758 struct i2c_adapter *ddc;
759 /** private: */
760 /**
761 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
762 */
763 struct mutex hpd_mutex;
764 /**
765 * @hpd_cb: Hot plug detection callback, registered with
766 * drm_bridge_hpd_enable().
767 */
768 void (*hpd_cb)(void *data, enum drm_connector_status status);
769 /**
770 * @hpd_data: Private data passed to the Hot plug detection callback
771 * @hpd_cb.
772 */
773 void *hpd_data;
774 };
775
776 static inline struct drm_bridge *
drm_priv_to_bridge(struct drm_private_obj * priv)777 drm_priv_to_bridge(struct drm_private_obj *priv)
778 {
779 return container_of(priv, struct drm_bridge, base);
780 }
781
782 void drm_bridge_add(struct drm_bridge *bridge);
783 int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
784 void drm_bridge_remove(struct drm_bridge *bridge);
785 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
786 struct drm_bridge *previous,
787 enum drm_bridge_attach_flags flags);
788
789 #ifdef CONFIG_OF
790 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
791 #else
of_drm_find_bridge(struct device_node * np)792 static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
793 {
794 return NULL;
795 }
796 #endif
797
798 /**
799 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
800 * @bridge: bridge object
801 *
802 * RETURNS:
803 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
804 */
805 static inline struct drm_bridge *
drm_bridge_get_next_bridge(struct drm_bridge * bridge)806 drm_bridge_get_next_bridge(struct drm_bridge *bridge)
807 {
808 if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
809 return NULL;
810
811 return list_next_entry(bridge, chain_node);
812 }
813
814 /**
815 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
816 * @bridge: bridge object
817 *
818 * RETURNS:
819 * the previous bridge in the chain, or NULL if @bridge is the first.
820 */
821 static inline struct drm_bridge *
drm_bridge_get_prev_bridge(struct drm_bridge * bridge)822 drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
823 {
824 if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
825 return NULL;
826
827 return list_prev_entry(bridge, chain_node);
828 }
829
830 /**
831 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
832 * @encoder: encoder object
833 *
834 * RETURNS:
835 * the first bridge in the chain, or NULL if @encoder has no bridge attached
836 * to it.
837 */
838 static inline struct drm_bridge *
drm_bridge_chain_get_first_bridge(struct drm_encoder * encoder)839 drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
840 {
841 return list_first_entry_or_null(&encoder->bridge_chain,
842 struct drm_bridge, chain_node);
843 }
844
845 /**
846 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
847 * @encoder: the encoder to iterate bridges on
848 * @bridge: a bridge pointer updated to point to the current bridge at each
849 * iteration
850 *
851 * Iterate over all bridges present in the bridge chain attached to @encoder.
852 */
853 #define drm_for_each_bridge_in_chain(encoder, bridge) \
854 list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
855
856 bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
857 const struct drm_display_mode *mode,
858 struct drm_display_mode *adjusted_mode);
859 enum drm_mode_status
860 drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
861 const struct drm_display_info *info,
862 const struct drm_display_mode *mode);
863 void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
864 const struct drm_display_mode *mode,
865 const struct drm_display_mode *adjusted_mode);
866
867 int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
868 struct drm_crtc_state *crtc_state,
869 struct drm_connector_state *conn_state);
870 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
871 struct drm_atomic_state *state);
872 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
873 struct drm_atomic_state *state);
874 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
875 struct drm_atomic_state *state);
876 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
877 struct drm_atomic_state *state);
878
879 u32 *
880 drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
881 struct drm_bridge_state *bridge_state,
882 struct drm_crtc_state *crtc_state,
883 struct drm_connector_state *conn_state,
884 u32 output_fmt,
885 unsigned int *num_input_fmts);
886
887 enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
888 int drm_bridge_get_modes(struct drm_bridge *bridge,
889 struct drm_connector *connector);
890 struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
891 struct drm_connector *connector);
892 void drm_bridge_hpd_enable(struct drm_bridge *bridge,
893 void (*cb)(void *data,
894 enum drm_connector_status status),
895 void *data);
896 void drm_bridge_hpd_disable(struct drm_bridge *bridge);
897 void drm_bridge_hpd_notify(struct drm_bridge *bridge,
898 enum drm_connector_status status);
899
900 #ifdef CONFIG_DRM_PANEL_BRIDGE
901 bool drm_bridge_is_panel(const struct drm_bridge *bridge);
902 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
903 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
904 u32 connector_type);
905 void drm_panel_bridge_remove(struct drm_bridge *bridge);
906 int drm_panel_bridge_set_orientation(struct drm_connector *connector,
907 struct drm_bridge *bridge);
908 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
909 struct drm_panel *panel);
910 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
911 struct drm_panel *panel,
912 u32 connector_type);
913 struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
914 struct drm_panel *panel);
915 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
916 #else
drm_bridge_is_panel(const struct drm_bridge * bridge)917 static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
918 {
919 return false;
920 }
921
drm_panel_bridge_set_orientation(struct drm_connector * connector,struct drm_bridge * bridge)922 static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,
923 struct drm_bridge *bridge)
924 {
925 return -EINVAL;
926 }
927 #endif
928
929 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
930 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
931 u32 port, u32 endpoint);
932 struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
933 u32 port, u32 endpoint);
934 #else
devm_drm_of_get_bridge(struct device * dev,struct device_node * node,u32 port,u32 endpoint)935 static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
936 struct device_node *node,
937 u32 port,
938 u32 endpoint)
939 {
940 return ERR_PTR(-ENODEV);
941 }
942
drmm_of_get_bridge(struct drm_device * drm,struct device_node * node,u32 port,u32 endpoint)943 static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
944 struct device_node *node,
945 u32 port,
946 u32 endpoint)
947 {
948 return ERR_PTR(-ENODEV);
949 }
950 #endif
951
952 #endif
953