Line data Source code
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 *
793 : drm_priv_to_bridge(struct drm_private_obj *priv)
794 : {
795 0 : return container_of(priv, struct drm_bridge, base);
796 : }
797 :
798 : void drm_bridge_add(struct drm_bridge *bridge);
799 : void drm_bridge_remove(struct drm_bridge *bridge);
800 : int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
801 : struct drm_bridge *previous,
802 : enum drm_bridge_attach_flags flags);
803 :
804 : #ifdef CONFIG_OF
805 : struct drm_bridge *of_drm_find_bridge(struct device_node *np);
806 : #else
807 : static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
808 : {
809 : return NULL;
810 : }
811 : #endif
812 :
813 : /**
814 : * drm_bridge_get_next_bridge() - Get the next bridge in the chain
815 : * @bridge: bridge object
816 : *
817 : * RETURNS:
818 : * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
819 : */
820 : static inline struct drm_bridge *
821 : drm_bridge_get_next_bridge(struct drm_bridge *bridge)
822 : {
823 0 : if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
824 : return NULL;
825 :
826 0 : return list_next_entry(bridge, chain_node);
827 : }
828 :
829 : /**
830 : * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
831 : * @bridge: bridge object
832 : *
833 : * RETURNS:
834 : * the previous bridge in the chain, or NULL if @bridge is the first.
835 : */
836 : static inline struct drm_bridge *
837 : drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
838 : {
839 0 : if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
840 : return NULL;
841 :
842 0 : return list_prev_entry(bridge, chain_node);
843 : }
844 :
845 : /**
846 : * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
847 : * @encoder: encoder object
848 : *
849 : * RETURNS:
850 : * the first bridge in the chain, or NULL if @encoder has no bridge attached
851 : * to it.
852 : */
853 : static inline struct drm_bridge *
854 : drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
855 : {
856 0 : return list_first_entry_or_null(&encoder->bridge_chain,
857 : struct drm_bridge, chain_node);
858 : }
859 :
860 : /**
861 : * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
862 : * @encoder: the encoder to iterate bridges on
863 : * @bridge: a bridge pointer updated to point to the current bridge at each
864 : * iteration
865 : *
866 : * Iterate over all bridges present in the bridge chain attached to @encoder.
867 : */
868 : #define drm_for_each_bridge_in_chain(encoder, bridge) \
869 : list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
870 :
871 : bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
872 : const struct drm_display_mode *mode,
873 : struct drm_display_mode *adjusted_mode);
874 : enum drm_mode_status
875 : drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
876 : const struct drm_display_info *info,
877 : const struct drm_display_mode *mode);
878 : void drm_bridge_chain_disable(struct drm_bridge *bridge);
879 : void drm_bridge_chain_post_disable(struct drm_bridge *bridge);
880 : void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
881 : const struct drm_display_mode *mode,
882 : const struct drm_display_mode *adjusted_mode);
883 : void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
884 : void drm_bridge_chain_enable(struct drm_bridge *bridge);
885 :
886 : int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
887 : struct drm_crtc_state *crtc_state,
888 : struct drm_connector_state *conn_state);
889 : void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
890 : struct drm_atomic_state *state);
891 : void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
892 : struct drm_atomic_state *state);
893 : void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
894 : struct drm_atomic_state *state);
895 : void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
896 : struct drm_atomic_state *state);
897 :
898 : u32 *
899 : drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
900 : struct drm_bridge_state *bridge_state,
901 : struct drm_crtc_state *crtc_state,
902 : struct drm_connector_state *conn_state,
903 : u32 output_fmt,
904 : unsigned int *num_input_fmts);
905 :
906 : enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
907 : int drm_bridge_get_modes(struct drm_bridge *bridge,
908 : struct drm_connector *connector);
909 : struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
910 : struct drm_connector *connector);
911 : void drm_bridge_hpd_enable(struct drm_bridge *bridge,
912 : void (*cb)(void *data,
913 : enum drm_connector_status status),
914 : void *data);
915 : void drm_bridge_hpd_disable(struct drm_bridge *bridge);
916 : void drm_bridge_hpd_notify(struct drm_bridge *bridge,
917 : enum drm_connector_status status);
918 :
919 : #ifdef CONFIG_DRM_PANEL_BRIDGE
920 : struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
921 : struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
922 : u32 connector_type);
923 : void drm_panel_bridge_remove(struct drm_bridge *bridge);
924 : struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
925 : struct drm_panel *panel);
926 : struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
927 : struct drm_panel *panel,
928 : u32 connector_type);
929 : struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
930 : #endif
931 :
932 : #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
933 : struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
934 : u32 port, u32 endpoint);
935 : #else
936 : static 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 : #endif
944 :
945 : #endif
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