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 * 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 */
664 struct 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 */
700 enum 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 */
733 struct 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
792 static inline struct drm_bridge *
drm_priv_to_bridge(struct drm_private_obj * priv)793 drm_priv_to_bridge(struct drm_private_obj *priv)
794 {
795 return container_of(priv, struct drm_bridge, base);
796 }
797
798 void drm_bridge_add(struct drm_bridge *bridge);
799 int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
800 void drm_bridge_remove(struct drm_bridge *bridge);
801 int 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
806 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
807 #else
of_drm_find_bridge(struct device_node * np)808 static 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 */
821 static inline struct drm_bridge *
drm_bridge_get_next_bridge(struct drm_bridge * bridge)822 drm_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 */
837 static inline struct drm_bridge *
drm_bridge_get_prev_bridge(struct drm_bridge * bridge)838 drm_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 */
854 static inline struct drm_bridge *
drm_bridge_chain_get_first_bridge(struct drm_encoder * encoder)855 drm_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
872 bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
873 const struct drm_display_mode *mode,
874 struct drm_display_mode *adjusted_mode);
875 enum drm_mode_status
876 drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
877 const struct drm_display_info *info,
878 const struct drm_display_mode *mode);
879 void drm_bridge_chain_disable(struct drm_bridge *bridge);
880 void drm_bridge_chain_post_disable(struct drm_bridge *bridge);
881 void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
882 const struct drm_display_mode *mode,
883 const struct drm_display_mode *adjusted_mode);
884 void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
885 void drm_bridge_chain_enable(struct drm_bridge *bridge);
886
887 int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
888 struct drm_crtc_state *crtc_state,
889 struct drm_connector_state *conn_state);
890 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
891 struct drm_atomic_state *state);
892 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
893 struct drm_atomic_state *state);
894 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
895 struct drm_atomic_state *state);
896 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
897 struct drm_atomic_state *state);
898
899 u32 *
900 drm_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
907 enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
908 int drm_bridge_get_modes(struct drm_bridge *bridge,
909 struct drm_connector *connector);
910 struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
911 struct drm_connector *connector);
912 void drm_bridge_hpd_enable(struct drm_bridge *bridge,
913 void (*cb)(void *data,
914 enum drm_connector_status status),
915 void *data);
916 void drm_bridge_hpd_disable(struct drm_bridge *bridge);
917 void drm_bridge_hpd_notify(struct drm_bridge *bridge,
918 enum drm_connector_status status);
919
920 #ifdef CONFIG_DRM_PANEL_BRIDGE
921 bool drm_bridge_is_panel(const struct drm_bridge *bridge);
922 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
923 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
924 u32 connector_type);
925 void drm_panel_bridge_remove(struct drm_bridge *bridge);
926 int drm_panel_bridge_set_orientation(struct drm_connector *connector,
927 struct drm_bridge *bridge);
928 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
929 struct drm_panel *panel);
930 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
931 struct drm_panel *panel,
932 u32 connector_type);
933 struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
934 struct drm_panel *panel);
935 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
936 #else
drm_bridge_is_panel(const struct drm_bridge * bridge)937 static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
938 {
939 return false;
940 }
941
drm_panel_bridge_set_orientation(struct drm_connector * connector,struct drm_bridge * bridge)942 static 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)
950 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
951 u32 port, u32 endpoint);
952 struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
953 u32 port, u32 endpoint);
954 #else
devm_drm_of_get_bridge(struct device * dev,struct device_node * node,u32 port,u32 endpoint)955 static 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
drmm_of_get_bridge(struct drm_device * drm,struct device_node * node,u32 port,u32 endpoint)963 static 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
973