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 device_node;
36
37 struct drm_bridge;
38 struct drm_bridge_timings;
39 struct drm_connector;
40 struct drm_display_info;
41 struct drm_minor;
42 struct drm_panel;
43 struct edid;
44 struct i2c_adapter;
45
46 /**
47 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
48 */
49 enum drm_bridge_attach_flags {
50 /**
51 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge
52 * shall not create a drm_connector.
53 */
54 DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),
55 };
56
57 /**
58 * struct drm_bridge_funcs - drm_bridge control functions
59 */
60 struct drm_bridge_funcs {
61 /**
62 * @attach:
63 *
64 * This callback is invoked whenever our bridge is being attached to a
65 * &drm_encoder. The flags argument tunes the behaviour of the attach
66 * operation (see DRM_BRIDGE_ATTACH_*).
67 *
68 * The @attach callback is optional.
69 *
70 * RETURNS:
71 *
72 * Zero on success, error code on failure.
73 */
74 int (*attach)(struct drm_bridge *bridge,
75 enum drm_bridge_attach_flags flags);
76
77 /**
78 * @detach:
79 *
80 * This callback is invoked whenever our bridge is being detached from a
81 * &drm_encoder.
82 *
83 * The @detach callback is optional.
84 */
85 void (*detach)(struct drm_bridge *bridge);
86
87 /**
88 * @mode_valid:
89 *
90 * This callback is used to check if a specific mode is valid in this
91 * bridge. This should be implemented if the bridge has some sort of
92 * restriction in the modes it can display. For example, a given bridge
93 * may be responsible to set a clock value. If the clock can not
94 * produce all the values for the available modes then this callback
95 * can be used to restrict the number of modes to only the ones that
96 * can be displayed.
97 *
98 * This hook is used by the probe helpers to filter the mode list in
99 * drm_helper_probe_single_connector_modes(), and it is used by the
100 * atomic helpers to validate modes supplied by userspace in
101 * drm_atomic_helper_check_modeset().
102 *
103 * The @mode_valid callback is optional.
104 *
105 * NOTE:
106 *
107 * Since this function is both called from the check phase of an atomic
108 * commit, and the mode validation in the probe paths it is not allowed
109 * to look at anything else but the passed-in mode, and validate it
110 * against configuration-invariant hardware constraints. Any further
111 * limits which depend upon the configuration can only be checked in
112 * @mode_fixup.
113 *
114 * RETURNS:
115 *
116 * drm_mode_status Enum
117 */
118 enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
119 const struct drm_display_info *info,
120 const struct drm_display_mode *mode);
121
122 /**
123 * @mode_fixup:
124 *
125 * This callback is used to validate and adjust a mode. The parameter
126 * mode is the display mode that should be fed to the next element in
127 * the display chain, either the final &drm_connector or the next
128 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
129 * requires. It can be modified by this callback and does not need to
130 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
131 *
132 * This is the only hook that allows a bridge to reject a modeset. If
133 * this function passes all other callbacks must succeed for this
134 * configuration.
135 *
136 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
137 * is not called when &drm_bridge_funcs.atomic_check() is implemented,
138 * so only one of them should be provided.
139 *
140 * NOTE:
141 *
142 * This function is called in the check phase of atomic modesets, which
143 * can be aborted for any reason (including on userspace's request to
144 * just check whether a configuration would be possible). Drivers MUST
145 * NOT touch any persistent state (hardware or software) or data
146 * structures except the passed in @state parameter.
147 *
148 * Also beware that userspace can request its own custom modes, neither
149 * core nor helpers filter modes to the list of probe modes reported by
150 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
151 * that modes are filtered consistently put any bridge constraints and
152 * limits checks into @mode_valid.
153 *
154 * RETURNS:
155 *
156 * True if an acceptable configuration is possible, false if the modeset
157 * operation should be rejected.
158 */
159 bool (*mode_fixup)(struct drm_bridge *bridge,
160 const struct drm_display_mode *mode,
161 struct drm_display_mode *adjusted_mode);
162 /**
163 * @disable:
164 *
165 * This callback should disable the bridge. It is called right before
166 * the preceding element in the display pipe is disabled. If the
167 * preceding element is a bridge this means it's called before that
168 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
169 * it's called right before the &drm_encoder_helper_funcs.disable,
170 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
171 * hook.
172 *
173 * The bridge can assume that the display pipe (i.e. clocks and timing
174 * signals) feeding it is still running when this callback is called.
175 *
176 * The @disable callback is optional.
177 *
178 * NOTE:
179 *
180 * This is deprecated, do not use!
181 * New drivers shall use &drm_bridge_funcs.atomic_disable.
182 */
183 void (*disable)(struct drm_bridge *bridge);
184
185 /**
186 * @post_disable:
187 *
188 * This callback should disable the bridge. It is called right after the
189 * preceding element in the display pipe is disabled. If the preceding
190 * element is a bridge this means it's called after that bridge's
191 * @post_disable function. If the preceding element is a &drm_encoder
192 * it's called right after the encoder's
193 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
194 * or &drm_encoder_helper_funcs.dpms hook.
195 *
196 * The bridge must assume that the display pipe (i.e. clocks and timing
197 * signals) feeding it is no longer running when this callback is
198 * called.
199 *
200 * The @post_disable callback is optional.
201 *
202 * NOTE:
203 *
204 * This is deprecated, do not use!
205 * New drivers shall use &drm_bridge_funcs.atomic_post_disable.
206 */
207 void (*post_disable)(struct drm_bridge *bridge);
208
209 /**
210 * @mode_set:
211 *
212 * This callback should set the given mode on the bridge. It is called
213 * after the @mode_set callback for the preceding element in the display
214 * pipeline has been called already. If the bridge is the first element
215 * then this would be &drm_encoder_helper_funcs.mode_set. The display
216 * pipe (i.e. clocks and timing signals) is off when this function is
217 * called.
218 *
219 * The adjusted_mode parameter is the mode output by the CRTC for the
220 * first bridge in the chain. It can be different from the mode
221 * parameter that contains the desired mode for the connector at the end
222 * of the bridges chain, for instance when the first bridge in the chain
223 * performs scaling. The adjusted mode is mostly useful for the first
224 * bridge in the chain and is likely irrelevant for the other bridges.
225 *
226 * For atomic drivers the adjusted_mode is the mode stored in
227 * &drm_crtc_state.adjusted_mode.
228 *
229 * NOTE:
230 *
231 * This is deprecated, do not use!
232 * New drivers shall set their mode in the
233 * &drm_bridge_funcs.atomic_enable operation.
234 */
235 void (*mode_set)(struct drm_bridge *bridge,
236 const struct drm_display_mode *mode,
237 const struct drm_display_mode *adjusted_mode);
238 /**
239 * @pre_enable:
240 *
241 * This callback should enable the bridge. It is called right before
242 * the preceding element in the display pipe is enabled. If the
243 * preceding element is a bridge this means it's called before that
244 * bridge's @pre_enable function. If the preceding element is a
245 * &drm_encoder it's called right before the encoder's
246 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
247 * &drm_encoder_helper_funcs.dpms hook.
248 *
249 * The display pipe (i.e. clocks and timing signals) feeding this bridge
250 * will not yet be running when this callback is called. The bridge must
251 * not enable the display link feeding the next bridge in the chain (if
252 * there is one) when this callback is called.
253 *
254 * The @pre_enable callback is optional.
255 *
256 * NOTE:
257 *
258 * This is deprecated, do not use!
259 * New drivers shall use &drm_bridge_funcs.atomic_pre_enable.
260 */
261 void (*pre_enable)(struct drm_bridge *bridge);
262
263 /**
264 * @enable:
265 *
266 * This callback should enable the bridge. It is called right after
267 * the preceding element in the display pipe is enabled. If the
268 * preceding element is a bridge this means it's called after that
269 * bridge's @enable function. If the preceding element is a
270 * &drm_encoder it's called right after the encoder's
271 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
272 * &drm_encoder_helper_funcs.dpms hook.
273 *
274 * The bridge can assume that the display pipe (i.e. clocks and timing
275 * signals) feeding it is running when this callback is called. This
276 * callback must enable the display link feeding the next bridge in the
277 * chain if there is one.
278 *
279 * The @enable callback is optional.
280 *
281 * NOTE:
282 *
283 * This is deprecated, do not use!
284 * New drivers shall use &drm_bridge_funcs.atomic_enable.
285 */
286 void (*enable)(struct drm_bridge *bridge);
287
288 /**
289 * @atomic_pre_enable:
290 *
291 * This callback should enable the bridge. It is called right before
292 * the preceding element in the display pipe is enabled. If the
293 * preceding element is a bridge this means it's called before that
294 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
295 * element is a &drm_encoder it's called right before the encoder's
296 * &drm_encoder_helper_funcs.atomic_enable hook.
297 *
298 * The display pipe (i.e. clocks and timing signals) feeding this bridge
299 * will not yet be running when this callback is called. The bridge must
300 * not enable the display link feeding the next bridge in the chain (if
301 * there is one) when this callback is called.
302 *
303 * The @atomic_pre_enable callback is optional.
304 */
305 void (*atomic_pre_enable)(struct drm_bridge *bridge,
306 struct drm_bridge_state *old_bridge_state);
307
308 /**
309 * @atomic_enable:
310 *
311 * This callback should enable the bridge. It is called right after
312 * the preceding element in the display pipe is enabled. If the
313 * preceding element is a bridge this means it's called after that
314 * bridge's @atomic_enable or @enable function. If the preceding element
315 * is a &drm_encoder it's called right after the encoder's
316 * &drm_encoder_helper_funcs.atomic_enable hook.
317 *
318 * The bridge can assume that the display pipe (i.e. clocks and timing
319 * signals) feeding it is running when this callback is called. This
320 * callback must enable the display link feeding the next bridge in the
321 * chain if there is one.
322 *
323 * The @atomic_enable callback is optional.
324 */
325 void (*atomic_enable)(struct drm_bridge *bridge,
326 struct drm_bridge_state *old_bridge_state);
327 /**
328 * @atomic_disable:
329 *
330 * This callback should disable the bridge. It is called right before
331 * the preceding element in the display pipe is disabled. If the
332 * preceding element is a bridge this means it's called before that
333 * bridge's @atomic_disable or @disable vfunc. If the preceding element
334 * is a &drm_encoder it's called right before the
335 * &drm_encoder_helper_funcs.atomic_disable hook.
336 *
337 * The bridge can assume that the display pipe (i.e. clocks and timing
338 * signals) feeding it is still running when this callback is called.
339 *
340 * The @atomic_disable callback is optional.
341 */
342 void (*atomic_disable)(struct drm_bridge *bridge,
343 struct drm_bridge_state *old_bridge_state);
344
345 /**
346 * @atomic_post_disable:
347 *
348 * This callback should disable the bridge. It is called right after the
349 * preceding element in the display pipe is disabled. If the preceding
350 * element is a bridge this means it's called after that bridge's
351 * @atomic_post_disable or @post_disable function. If the preceding
352 * element is a &drm_encoder it's called right after the encoder's
353 * &drm_encoder_helper_funcs.atomic_disable hook.
354 *
355 * The bridge must assume that the display pipe (i.e. clocks and timing
356 * signals) feeding it is no longer running when this callback is
357 * called.
358 *
359 * The @atomic_post_disable callback is optional.
360 */
361 void (*atomic_post_disable)(struct drm_bridge *bridge,
362 struct drm_bridge_state *old_bridge_state);
363
364 /**
365 * @atomic_duplicate_state:
366 *
367 * Duplicate the current bridge state object (which is guaranteed to be
368 * non-NULL).
369 *
370 * The atomic_duplicate_state hook is mandatory if the bridge
371 * implements any of the atomic hooks, and should be left unassigned
372 * otherwise. For bridges that don't subclass &drm_bridge_state, the
373 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
374 * used to implement this hook.
375 *
376 * RETURNS:
377 * A valid drm_bridge_state object or NULL if the allocation fails.
378 */
379 struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
380
381 /**
382 * @atomic_destroy_state:
383 *
384 * Destroy a bridge state object previously allocated by
385 * &drm_bridge_funcs.atomic_duplicate_state().
386 *
387 * The atomic_destroy_state hook is mandatory if the bridge implements
388 * any of the atomic hooks, and should be left unassigned otherwise.
389 * For bridges that don't subclass &drm_bridge_state, the
390 * drm_atomic_helper_bridge_destroy_state() helper function shall be
391 * used to implement this hook.
392 */
393 void (*atomic_destroy_state)(struct drm_bridge *bridge,
394 struct drm_bridge_state *state);
395
396 /**
397 * @atomic_get_output_bus_fmts:
398 *
399 * Return the supported bus formats on the output end of a bridge.
400 * The returned array must be allocated with kmalloc() and will be
401 * freed by the caller. If the allocation fails, NULL should be
402 * returned. num_output_fmts must be set to the returned array size.
403 * Formats listed in the returned array should be listed in decreasing
404 * preference order (the core will try all formats until it finds one
405 * that works).
406 *
407 * This method is only called on the last element of the bridge chain
408 * as part of the bus format negotiation process that happens in
409 * &drm_atomic_bridge_chain_select_bus_fmts().
410 * This method is optional. When not implemented, the core will
411 * fall back to &drm_connector.display_info.bus_formats[0] if
412 * &drm_connector.display_info.num_bus_formats > 0,
413 * or to MEDIA_BUS_FMT_FIXED otherwise.
414 */
415 u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
416 struct drm_bridge_state *bridge_state,
417 struct drm_crtc_state *crtc_state,
418 struct drm_connector_state *conn_state,
419 unsigned int *num_output_fmts);
420
421 /**
422 * @atomic_get_input_bus_fmts:
423 *
424 * Return the supported bus formats on the input end of a bridge for
425 * a specific output bus format.
426 *
427 * The returned array must be allocated with kmalloc() and will be
428 * freed by the caller. If the allocation fails, NULL should be
429 * returned. num_input_fmts must be set to the returned array size.
430 * Formats listed in the returned array should be listed in decreasing
431 * preference order (the core will try all formats until it finds one
432 * that works). When the format is not supported NULL should be
433 * returned and num_input_fmts should be set to 0.
434 *
435 * This method is called on all elements of the bridge chain as part of
436 * the bus format negotiation process that happens in
437 * drm_atomic_bridge_chain_select_bus_fmts().
438 * This method is optional. When not implemented, the core will bypass
439 * bus format negotiation on this element of the bridge without
440 * failing, and the previous element in the chain will be passed
441 * MEDIA_BUS_FMT_FIXED as its output bus format.
442 *
443 * Bridge drivers that need to support being linked to bridges that are
444 * not supporting bus format negotiation should handle the
445 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
446 * sensible default value or extracting this information from somewhere
447 * else (FW property, &drm_display_mode, &drm_display_info, ...)
448 *
449 * Note: Even if input format selection on the first bridge has no
450 * impact on the negotiation process (bus format negotiation stops once
451 * we reach the first element of the chain), drivers are expected to
452 * return accurate input formats as the input format may be used to
453 * configure the CRTC output appropriately.
454 */
455 u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
456 struct drm_bridge_state *bridge_state,
457 struct drm_crtc_state *crtc_state,
458 struct drm_connector_state *conn_state,
459 u32 output_fmt,
460 unsigned int *num_input_fmts);
461
462 /**
463 * @atomic_check:
464 *
465 * This method is responsible for checking bridge state correctness.
466 * It can also check the state of the surrounding components in chain
467 * to make sure the whole pipeline can work properly.
468 *
469 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
470 * order (from the last to the first bridge).
471 *
472 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
473 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
474 * one of them should be provided.
475 *
476 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
477 * &drm_bridge_state.output_bus_cfg.flags it should happen in
478 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
479 * field is set to the next bridge
480 * &drm_bridge_state.input_bus_cfg.flags value or
481 * &drm_connector.display_info.bus_flags if the bridge is the last
482 * element in the chain.
483 *
484 * RETURNS:
485 * zero if the check passed, a negative error code otherwise.
486 */
487 int (*atomic_check)(struct drm_bridge *bridge,
488 struct drm_bridge_state *bridge_state,
489 struct drm_crtc_state *crtc_state,
490 struct drm_connector_state *conn_state);
491
492 /**
493 * @atomic_reset:
494 *
495 * Reset the bridge to a predefined state (or retrieve its current
496 * state) and return a &drm_bridge_state object matching this state.
497 * This function is called at attach time.
498 *
499 * The atomic_reset hook is mandatory if the bridge implements any of
500 * the atomic hooks, and should be left unassigned otherwise. For
501 * bridges that don't subclass &drm_bridge_state, the
502 * drm_atomic_helper_bridge_reset() helper function shall be used to
503 * implement this hook.
504 *
505 * Note that the atomic_reset() semantics is not exactly matching the
506 * reset() semantics found on other components (connector, plane, ...).
507 *
508 * 1. The reset operation happens when the bridge is attached, not when
509 * drm_mode_config_reset() is called
510 * 2. It's meant to be used exclusively on bridges that have been
511 * converted to the ATOMIC API
512 *
513 * RETURNS:
514 * A valid drm_bridge_state object in case of success, an ERR_PTR()
515 * giving the reason of the failure otherwise.
516 */
517 struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
518
519 /**
520 * @detect:
521 *
522 * Check if anything is attached to the bridge output.
523 *
524 * This callback is optional, if not implemented the bridge will be
525 * considered as always having a component attached to its output.
526 * Bridges that implement this callback shall set the
527 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
528 *
529 * RETURNS:
530 *
531 * drm_connector_status indicating the bridge output status.
532 */
533 enum drm_connector_status (*detect)(struct drm_bridge *bridge);
534
535 /**
536 * @get_modes:
537 *
538 * Fill all modes currently valid for the sink into the &drm_connector
539 * with drm_mode_probed_add().
540 *
541 * The @get_modes callback is mostly intended to support non-probeable
542 * displays such as many fixed panels. Bridges that support reading
543 * EDID shall leave @get_modes unimplemented and implement the
544 * &drm_bridge_funcs->edid_read callback instead.
545 *
546 * This callback is optional. Bridges that implement it shall set the
547 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
548 *
549 * The connector parameter shall be used for the sole purpose of
550 * filling modes, and shall not be stored internally by bridge drivers
551 * for future usage.
552 *
553 * RETURNS:
554 *
555 * The number of modes added by calling drm_mode_probed_add().
556 */
557 int (*get_modes)(struct drm_bridge *bridge,
558 struct drm_connector *connector);
559
560 /**
561 * @edid_read:
562 *
563 * Read the EDID data of the connected display.
564 *
565 * The @edid_read callback is the preferred way of reporting mode
566 * information for a display connected to the bridge output. Bridges
567 * that support reading EDID shall implement this callback and leave
568 * the @get_modes callback unimplemented.
569 *
570 * The caller of this operation shall first verify the output
571 * connection status and refrain from reading EDID from a disconnected
572 * output.
573 *
574 * This callback is optional. Bridges that implement it shall set the
575 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
576 *
577 * The connector parameter shall be used for the sole purpose of EDID
578 * retrieval, and shall not be stored internally by bridge drivers for
579 * future usage.
580 *
581 * RETURNS:
582 *
583 * An edid structure newly allocated with drm_edid_alloc() or returned
584 * from drm_edid_read() family of functions on success, or NULL
585 * otherwise. The caller is responsible for freeing the returned edid
586 * structure with drm_edid_free().
587 */
588 const struct drm_edid *(*edid_read)(struct drm_bridge *bridge,
589 struct drm_connector *connector);
590
591 /**
592 * @hpd_notify:
593 *
594 * Notify the bridge of hot plug detection.
595 *
596 * This callback is optional, it may be implemented by bridges that
597 * need to be notified of display connection or disconnection for
598 * internal reasons. One use case is to reset the internal state of CEC
599 * controllers for HDMI bridges.
600 */
601 void (*hpd_notify)(struct drm_bridge *bridge,
602 enum drm_connector_status status);
603
604 /**
605 * @hpd_enable:
606 *
607 * Enable hot plug detection. From now on the bridge shall call
608 * drm_bridge_hpd_notify() each time a change is detected in the output
609 * connection status, until hot plug detection gets disabled with
610 * @hpd_disable.
611 *
612 * This callback is optional and shall only be implemented by bridges
613 * that support hot-plug notification without polling. Bridges that
614 * implement it shall also implement the @hpd_disable callback and set
615 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
616 */
617 void (*hpd_enable)(struct drm_bridge *bridge);
618
619 /**
620 * @hpd_disable:
621 *
622 * Disable hot plug detection. Once this function returns the bridge
623 * shall not call drm_bridge_hpd_notify() when a change in the output
624 * connection status occurs.
625 *
626 * This callback is optional and shall only be implemented by bridges
627 * that support hot-plug notification without polling. Bridges that
628 * implement it shall also implement the @hpd_enable callback and set
629 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
630 */
631 void (*hpd_disable)(struct drm_bridge *bridge);
632
633 /**
634 * @hdmi_tmds_char_rate_valid:
635 *
636 * Check whether a particular TMDS character rate is supported by the
637 * driver.
638 *
639 * This callback is optional and should only be implemented by the
640 * bridges that take part in the HDMI connector implementation. Bridges
641 * that implement it shall set the DRM_BRIDGE_OP_HDMI flag in their
642 * &drm_bridge->ops.
643 *
644 * Returns:
645 *
646 * Either &drm_mode_status.MODE_OK or one of the failure reasons
647 * in &enum drm_mode_status.
648 */
649 enum drm_mode_status
650 (*hdmi_tmds_char_rate_valid)(const struct drm_bridge *bridge,
651 const struct drm_display_mode *mode,
652 unsigned long long tmds_rate);
653
654 /**
655 * @hdmi_clear_infoframe:
656 *
657 * This callback clears the infoframes in the hardware during commit.
658 * It will be called multiple times, once for every disabled infoframe
659 * type.
660 *
661 * This callback is optional but it must be implemented by bridges that
662 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.
663 */
664 int (*hdmi_clear_infoframe)(struct drm_bridge *bridge,
665 enum hdmi_infoframe_type type);
666 /**
667 * @hdmi_write_infoframe:
668 *
669 * Program the infoframe into the hardware. It will be called multiple
670 * times, once for every updated infoframe type.
671 *
672 * This callback is optional but it must be implemented by bridges that
673 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.
674 */
675 int (*hdmi_write_infoframe)(struct drm_bridge *bridge,
676 enum hdmi_infoframe_type type,
677 const u8 *buffer, size_t len);
678
679 /**
680 * @debugfs_init:
681 *
682 * Allows bridges to create bridge-specific debugfs files.
683 */
684 void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);
685 };
686
687 /**
688 * struct drm_bridge_timings - timing information for the bridge
689 */
690 struct drm_bridge_timings {
691 /**
692 * @input_bus_flags:
693 *
694 * Tells what additional settings for the pixel data on the bus
695 * this bridge requires (like pixel signal polarity). See also
696 * &drm_display_info->bus_flags.
697 */
698 u32 input_bus_flags;
699 /**
700 * @setup_time_ps:
701 *
702 * Defines the time in picoseconds the input data lines must be
703 * stable before the clock edge.
704 */
705 u32 setup_time_ps;
706 /**
707 * @hold_time_ps:
708 *
709 * Defines the time in picoseconds taken for the bridge to sample the
710 * input signal after the clock edge.
711 */
712 u32 hold_time_ps;
713 /**
714 * @dual_link:
715 *
716 * True if the bus operates in dual-link mode. The exact meaning is
717 * dependent on the bus type. For LVDS buses, this indicates that even-
718 * and odd-numbered pixels are received on separate links.
719 */
720 bool dual_link;
721 };
722
723 /**
724 * enum drm_bridge_ops - Bitmask of operations supported by the bridge
725 */
726 enum drm_bridge_ops {
727 /**
728 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
729 * its output. Bridges that set this flag shall implement the
730 * &drm_bridge_funcs->detect callback.
731 */
732 DRM_BRIDGE_OP_DETECT = BIT(0),
733 /**
734 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
735 * connected to its output. Bridges that set this flag shall implement
736 * the &drm_bridge_funcs->edid_read callback.
737 */
738 DRM_BRIDGE_OP_EDID = BIT(1),
739 /**
740 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
741 * without requiring polling. Bridges that set this flag shall
742 * implement the &drm_bridge_funcs->hpd_enable and
743 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
744 * and disabling hot-plug detection dynamically.
745 */
746 DRM_BRIDGE_OP_HPD = BIT(2),
747 /**
748 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
749 * by the display at its output. This does not include reading EDID
750 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
751 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
752 */
753 DRM_BRIDGE_OP_MODES = BIT(3),
754 /**
755 * @DRM_BRIDGE_OP_HDMI: The bridge provides HDMI connector operations,
756 * including infoframes support. Bridges that set this flag must
757 * implement the &drm_bridge_funcs->write_infoframe callback.
758 *
759 * Note: currently there can be at most one bridge in a chain that sets
760 * this bit. This is to simplify corresponding glue code in connector
761 * drivers.
762 */
763 DRM_BRIDGE_OP_HDMI = BIT(4),
764 };
765
766 /**
767 * struct drm_bridge - central DRM bridge control structure
768 */
769 struct drm_bridge {
770 /** @base: inherit from &drm_private_object */
771 struct drm_private_obj base;
772 /** @dev: DRM device this bridge belongs to */
773 struct drm_device *dev;
774 /** @encoder: encoder to which this bridge is connected */
775 struct drm_encoder *encoder;
776 /** @chain_node: used to form a bridge chain */
777 struct list_head chain_node;
778 /** @of_node: device node pointer to the bridge */
779 struct device_node *of_node;
780 /** @list: to keep track of all added bridges */
781 struct list_head list;
782 /**
783 * @timings:
784 *
785 * the timing specification for the bridge, if any (may be NULL)
786 */
787 const struct drm_bridge_timings *timings;
788 /** @funcs: control functions */
789 const struct drm_bridge_funcs *funcs;
790 /** @driver_private: pointer to the bridge driver's internal context */
791 void *driver_private;
792 /** @ops: bitmask of operations supported by the bridge */
793 enum drm_bridge_ops ops;
794 /**
795 * @type: Type of the connection at the bridge output
796 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
797 * identifies the type of connected display.
798 */
799 int type;
800 /**
801 * @interlace_allowed: Indicate that the bridge can handle interlaced
802 * modes.
803 */
804 bool interlace_allowed;
805 /**
806 * @pre_enable_prev_first: The bridge requires that the prev
807 * bridge @pre_enable function is called before its @pre_enable,
808 * and conversely for post_disable. This is most frequently a
809 * requirement for DSI devices which need the host to be initialised
810 * before the peripheral.
811 */
812 bool pre_enable_prev_first;
813 /**
814 * @ddc: Associated I2C adapter for DDC access, if any.
815 */
816 struct i2c_adapter *ddc;
817 /** private: */
818 /**
819 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
820 */
821 struct mutex hpd_mutex;
822 /**
823 * @hpd_cb: Hot plug detection callback, registered with
824 * drm_bridge_hpd_enable().
825 */
826 void (*hpd_cb)(void *data, enum drm_connector_status status);
827 /**
828 * @hpd_data: Private data passed to the Hot plug detection callback
829 * @hpd_cb.
830 */
831 void *hpd_data;
832
833 /**
834 * @vendor: Vendor of the product to be used for the SPD InfoFrame
835 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.
836 */
837 const char *vendor;
838
839 /**
840 * @product: Name of the product to be used for the SPD InfoFrame
841 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.
842 */
843 const char *product;
844
845 /**
846 * @supported_formats: Bitmask of @hdmi_colorspace listing supported
847 * output formats. This is only relevant if @DRM_BRIDGE_OP_HDMI is set.
848 */
849 unsigned int supported_formats;
850
851 /**
852 * @max_bpc: Maximum bits per char the HDMI bridge supports. Allowed
853 * values are 8, 10 and 12. This is only relevant if
854 * @DRM_BRIDGE_OP_HDMI is set.
855 */
856 unsigned int max_bpc;
857 };
858
859 static inline struct drm_bridge *
860 drm_priv_to_bridge(struct drm_private_obj *priv)
861 {
862 return container_of(priv, struct drm_bridge, base);
863 }
864
865 void drm_bridge_add(struct drm_bridge *bridge);
866 int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
867 void drm_bridge_remove(struct drm_bridge *bridge);
868 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
869 struct drm_bridge *previous,
870 enum drm_bridge_attach_flags flags);
871
872 #ifdef CONFIG_OF
873 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
874 #else
875 static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
876 {
877 return NULL;
878 }
879 #endif
880
881 /**
882 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
883 * @bridge: bridge object
884 *
885 * RETURNS:
886 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
887 */
888 static inline struct drm_bridge *
889 drm_bridge_get_next_bridge(struct drm_bridge *bridge)
890 {
891 if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
892 return NULL;
893
894 return list_next_entry(bridge, chain_node);
895 }
896
897 /**
898 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
899 * @bridge: bridge object
900 *
901 * RETURNS:
902 * the previous bridge in the chain, or NULL if @bridge is the first.
903 */
904 static inline struct drm_bridge *
905 drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
906 {
907 if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
908 return NULL;
909
910 return list_prev_entry(bridge, chain_node);
911 }
912
913 /**
914 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
915 * @encoder: encoder object
916 *
917 * RETURNS:
918 * the first bridge in the chain, or NULL if @encoder has no bridge attached
919 * to it.
920 */
921 static inline struct drm_bridge *
922 drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
923 {
924 return list_first_entry_or_null(&encoder->bridge_chain,
925 struct drm_bridge, chain_node);
926 }
927
928 /**
929 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
930 * @encoder: the encoder to iterate bridges on
931 * @bridge: a bridge pointer updated to point to the current bridge at each
932 * iteration
933 *
934 * Iterate over all bridges present in the bridge chain attached to @encoder.
935 */
936 #define drm_for_each_bridge_in_chain(encoder, bridge) \
937 list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
938
939 enum drm_mode_status
940 drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
941 const struct drm_display_info *info,
942 const struct drm_display_mode *mode);
943 void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
944 const struct drm_display_mode *mode,
945 const struct drm_display_mode *adjusted_mode);
946
947 int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
948 struct drm_crtc_state *crtc_state,
949 struct drm_connector_state *conn_state);
950 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
951 struct drm_atomic_state *state);
952 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
953 struct drm_atomic_state *state);
954 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
955 struct drm_atomic_state *state);
956 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
957 struct drm_atomic_state *state);
958
959 u32 *
960 drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
961 struct drm_bridge_state *bridge_state,
962 struct drm_crtc_state *crtc_state,
963 struct drm_connector_state *conn_state,
964 u32 output_fmt,
965 unsigned int *num_input_fmts);
966
967 enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
968 int drm_bridge_get_modes(struct drm_bridge *bridge,
969 struct drm_connector *connector);
970 const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge,
971 struct drm_connector *connector);
972 void drm_bridge_hpd_enable(struct drm_bridge *bridge,
973 void (*cb)(void *data,
974 enum drm_connector_status status),
975 void *data);
976 void drm_bridge_hpd_disable(struct drm_bridge *bridge);
977 void drm_bridge_hpd_notify(struct drm_bridge *bridge,
978 enum drm_connector_status status);
979
980 #ifdef CONFIG_DRM_PANEL_BRIDGE
981 bool drm_bridge_is_panel(const struct drm_bridge *bridge);
982 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
983 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
984 u32 connector_type);
985 void drm_panel_bridge_remove(struct drm_bridge *bridge);
986 int drm_panel_bridge_set_orientation(struct drm_connector *connector,
987 struct drm_bridge *bridge);
988 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
989 struct drm_panel *panel);
990 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
991 struct drm_panel *panel,
992 u32 connector_type);
993 struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
994 struct drm_panel *panel);
995 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
996 #else
997 static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
998 {
999 return false;
1000 }
1001
1002 static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,
1003 struct drm_bridge *bridge)
1004 {
1005 return -EINVAL;
1006 }
1007 #endif
1008
1009 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
1010 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
1011 u32 port, u32 endpoint);
1012 struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
1013 u32 port, u32 endpoint);
1014 #else
1015 static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
1016 struct device_node *node,
1017 u32 port,
1018 u32 endpoint)
1019 {
1020 return ERR_PTR(-ENODEV);
1021 }
1022
1023 static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
1024 struct device_node *node,
1025 u32 port,
1026 u32 endpoint)
1027 {
1028 return ERR_PTR(-ENODEV);
1029 }
1030 #endif
1031
1032 #endif
1033
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