xref: /linux/include/drm/drm_bridge.h (revision 2c1ed907520c50326b8f604907a8478b27881a2e)
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 hdmi_codec_daifmt;
45 struct hdmi_codec_params;
46 struct i2c_adapter;
47 
48 /**
49  * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
50  */
51 enum drm_bridge_attach_flags {
52 	/**
53 	 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge
54 	 * shall not create a drm_connector.
55 	 */
56 	DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),
57 };
58 
59 /**
60  * struct drm_bridge_funcs - drm_bridge control functions
61  */
62 struct drm_bridge_funcs {
63 	/**
64 	 * @attach:
65 	 *
66 	 * This callback is invoked whenever our bridge is being attached to a
67 	 * &drm_encoder. The flags argument tunes the behaviour of the attach
68 	 * operation (see DRM_BRIDGE_ATTACH_*).
69 	 *
70 	 * The @attach callback is optional.
71 	 *
72 	 * RETURNS:
73 	 *
74 	 * Zero on success, error code on failure.
75 	 */
76 	int (*attach)(struct drm_bridge *bridge,
77 		      enum drm_bridge_attach_flags flags);
78 
79 	/**
80 	 * @detach:
81 	 *
82 	 * This callback is invoked whenever our bridge is being detached from a
83 	 * &drm_encoder.
84 	 *
85 	 * The @detach callback is optional.
86 	 */
87 	void (*detach)(struct drm_bridge *bridge);
88 
89 	/**
90 	 * @mode_valid:
91 	 *
92 	 * This callback is used to check if a specific mode is valid in this
93 	 * bridge. This should be implemented if the bridge has some sort of
94 	 * restriction in the modes it can display. For example, a given bridge
95 	 * may be responsible to set a clock value. If the clock can not
96 	 * produce all the values for the available modes then this callback
97 	 * can be used to restrict the number of modes to only the ones that
98 	 * can be displayed.
99 	 *
100 	 * This hook is used by the probe helpers to filter the mode list in
101 	 * drm_helper_probe_single_connector_modes(), and it is used by the
102 	 * atomic helpers to validate modes supplied by userspace in
103 	 * drm_atomic_helper_check_modeset().
104 	 *
105 	 * The @mode_valid callback is optional.
106 	 *
107 	 * NOTE:
108 	 *
109 	 * Since this function is both called from the check phase of an atomic
110 	 * commit, and the mode validation in the probe paths it is not allowed
111 	 * to look at anything else but the passed-in mode, and validate it
112 	 * against configuration-invariant hardware constraints. Any further
113 	 * limits which depend upon the configuration can only be checked in
114 	 * @mode_fixup.
115 	 *
116 	 * RETURNS:
117 	 *
118 	 * drm_mode_status Enum
119 	 */
120 	enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
121 					   const struct drm_display_info *info,
122 					   const struct drm_display_mode *mode);
123 
124 	/**
125 	 * @mode_fixup:
126 	 *
127 	 * This callback is used to validate and adjust a mode. The parameter
128 	 * mode is the display mode that should be fed to the next element in
129 	 * the display chain, either the final &drm_connector or the next
130 	 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
131 	 * requires. It can be modified by this callback and does not need to
132 	 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
133 	 *
134 	 * This is the only hook that allows a bridge to reject a modeset. If
135 	 * this function passes all other callbacks must succeed for this
136 	 * configuration.
137 	 *
138 	 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
139 	 * is not called when &drm_bridge_funcs.atomic_check() is implemented,
140 	 * so only one of them should be provided.
141 	 *
142 	 * NOTE:
143 	 *
144 	 * This function is called in the check phase of atomic modesets, which
145 	 * can be aborted for any reason (including on userspace's request to
146 	 * just check whether a configuration would be possible). Drivers MUST
147 	 * NOT touch any persistent state (hardware or software) or data
148 	 * structures except the passed in @state parameter.
149 	 *
150 	 * Also beware that userspace can request its own custom modes, neither
151 	 * core nor helpers filter modes to the list of probe modes reported by
152 	 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
153 	 * that modes are filtered consistently put any bridge constraints and
154 	 * limits checks into @mode_valid.
155 	 *
156 	 * RETURNS:
157 	 *
158 	 * True if an acceptable configuration is possible, false if the modeset
159 	 * operation should be rejected.
160 	 */
161 	bool (*mode_fixup)(struct drm_bridge *bridge,
162 			   const struct drm_display_mode *mode,
163 			   struct drm_display_mode *adjusted_mode);
164 	/**
165 	 * @disable:
166 	 *
167 	 * This callback should disable the bridge. It is called right before
168 	 * the preceding element in the display pipe is disabled. If the
169 	 * preceding element is a bridge this means it's called before that
170 	 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
171 	 * it's called right before the &drm_encoder_helper_funcs.disable,
172 	 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
173 	 * hook.
174 	 *
175 	 * The bridge can assume that the display pipe (i.e. clocks and timing
176 	 * signals) feeding it is still running when this callback is called.
177 	 *
178 	 * The @disable callback is optional.
179 	 *
180 	 * NOTE:
181 	 *
182 	 * This is deprecated, do not use!
183 	 * New drivers shall use &drm_bridge_funcs.atomic_disable.
184 	 */
185 	void (*disable)(struct drm_bridge *bridge);
186 
187 	/**
188 	 * @post_disable:
189 	 *
190 	 * This callback should disable the bridge. It is called right after the
191 	 * preceding element in the display pipe is disabled. If the preceding
192 	 * element is a bridge this means it's called after that bridge's
193 	 * @post_disable function. If the preceding element is a &drm_encoder
194 	 * it's called right after the encoder's
195 	 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
196 	 * or &drm_encoder_helper_funcs.dpms hook.
197 	 *
198 	 * The bridge must assume that the display pipe (i.e. clocks and timing
199 	 * signals) feeding it is no longer running when this callback is
200 	 * called.
201 	 *
202 	 * The @post_disable callback is optional.
203 	 *
204 	 * NOTE:
205 	 *
206 	 * This is deprecated, do not use!
207 	 * New drivers shall use &drm_bridge_funcs.atomic_post_disable.
208 	 */
209 	void (*post_disable)(struct drm_bridge *bridge);
210 
211 	/**
212 	 * @mode_set:
213 	 *
214 	 * This callback should set the given mode on the bridge. It is called
215 	 * after the @mode_set callback for the preceding element in the display
216 	 * pipeline has been called already. If the bridge is the first element
217 	 * then this would be &drm_encoder_helper_funcs.mode_set. The display
218 	 * pipe (i.e.  clocks and timing signals) is off when this function is
219 	 * called.
220 	 *
221 	 * The adjusted_mode parameter is the mode output by the CRTC for the
222 	 * first bridge in the chain. It can be different from the mode
223 	 * parameter that contains the desired mode for the connector at the end
224 	 * of the bridges chain, for instance when the first bridge in the chain
225 	 * performs scaling. The adjusted mode is mostly useful for the first
226 	 * bridge in the chain and is likely irrelevant for the other bridges.
227 	 *
228 	 * For atomic drivers the adjusted_mode is the mode stored in
229 	 * &drm_crtc_state.adjusted_mode.
230 	 *
231 	 * NOTE:
232 	 *
233 	 * This is deprecated, do not use!
234 	 * New drivers shall set their mode in the
235 	 * &drm_bridge_funcs.atomic_enable operation.
236 	 */
237 	void (*mode_set)(struct drm_bridge *bridge,
238 			 const struct drm_display_mode *mode,
239 			 const struct drm_display_mode *adjusted_mode);
240 	/**
241 	 * @pre_enable:
242 	 *
243 	 * This callback should enable the bridge. It is called right before
244 	 * the preceding element in the display pipe is enabled. If the
245 	 * preceding element is a bridge this means it's called before that
246 	 * bridge's @pre_enable function. If the preceding element is a
247 	 * &drm_encoder it's called right before the encoder's
248 	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
249 	 * &drm_encoder_helper_funcs.dpms hook.
250 	 *
251 	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
252 	 * will not yet be running when this callback is called. The bridge must
253 	 * not enable the display link feeding the next bridge in the chain (if
254 	 * there is one) when this callback is called.
255 	 *
256 	 * The @pre_enable callback is optional.
257 	 *
258 	 * NOTE:
259 	 *
260 	 * This is deprecated, do not use!
261 	 * New drivers shall use &drm_bridge_funcs.atomic_pre_enable.
262 	 */
263 	void (*pre_enable)(struct drm_bridge *bridge);
264 
265 	/**
266 	 * @enable:
267 	 *
268 	 * This callback should enable the bridge. It is called right after
269 	 * the preceding element in the display pipe is enabled. If the
270 	 * preceding element is a bridge this means it's called after that
271 	 * bridge's @enable function. If the preceding element is a
272 	 * &drm_encoder it's called right after the encoder's
273 	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
274 	 * &drm_encoder_helper_funcs.dpms hook.
275 	 *
276 	 * The bridge can assume that the display pipe (i.e. clocks and timing
277 	 * signals) feeding it is running when this callback is called. This
278 	 * callback must enable the display link feeding the next bridge in the
279 	 * chain if there is one.
280 	 *
281 	 * The @enable callback is optional.
282 	 *
283 	 * NOTE:
284 	 *
285 	 * This is deprecated, do not use!
286 	 * New drivers shall use &drm_bridge_funcs.atomic_enable.
287 	 */
288 	void (*enable)(struct drm_bridge *bridge);
289 
290 	/**
291 	 * @atomic_pre_enable:
292 	 *
293 	 * This callback should enable the bridge. It is called right before
294 	 * the preceding element in the display pipe is enabled. If the
295 	 * preceding element is a bridge this means it's called before that
296 	 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
297 	 * element is a &drm_encoder it's called right before the encoder's
298 	 * &drm_encoder_helper_funcs.atomic_enable hook.
299 	 *
300 	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
301 	 * will not yet be running when this callback is called. The bridge must
302 	 * not enable the display link feeding the next bridge in the chain (if
303 	 * there is one) when this callback is called.
304 	 *
305 	 * The @atomic_pre_enable callback is optional.
306 	 */
307 	void (*atomic_pre_enable)(struct drm_bridge *bridge,
308 				  struct drm_bridge_state *old_bridge_state);
309 
310 	/**
311 	 * @atomic_enable:
312 	 *
313 	 * This callback should enable the bridge. It is called right after
314 	 * the preceding element in the display pipe is enabled. If the
315 	 * preceding element is a bridge this means it's called after that
316 	 * bridge's @atomic_enable or @enable function. If the preceding element
317 	 * is a &drm_encoder it's called right after the encoder's
318 	 * &drm_encoder_helper_funcs.atomic_enable hook.
319 	 *
320 	 * The bridge can assume that the display pipe (i.e. clocks and timing
321 	 * signals) feeding it is running when this callback is called. This
322 	 * callback must enable the display link feeding the next bridge in the
323 	 * chain if there is one.
324 	 *
325 	 * The @atomic_enable callback is optional.
326 	 */
327 	void (*atomic_enable)(struct drm_bridge *bridge,
328 			      struct drm_bridge_state *old_bridge_state);
329 	/**
330 	 * @atomic_disable:
331 	 *
332 	 * This callback should disable the bridge. It is called right before
333 	 * the preceding element in the display pipe is disabled. If the
334 	 * preceding element is a bridge this means it's called before that
335 	 * bridge's @atomic_disable or @disable vfunc. If the preceding element
336 	 * is a &drm_encoder it's called right before the
337 	 * &drm_encoder_helper_funcs.atomic_disable hook.
338 	 *
339 	 * The bridge can assume that the display pipe (i.e. clocks and timing
340 	 * signals) feeding it is still running when this callback is called.
341 	 *
342 	 * The @atomic_disable callback is optional.
343 	 */
344 	void (*atomic_disable)(struct drm_bridge *bridge,
345 			       struct drm_bridge_state *old_bridge_state);
346 
347 	/**
348 	 * @atomic_post_disable:
349 	 *
350 	 * This callback should disable the bridge. It is called right after the
351 	 * preceding element in the display pipe is disabled. If the preceding
352 	 * element is a bridge this means it's called after that bridge's
353 	 * @atomic_post_disable or @post_disable function. If the preceding
354 	 * element is a &drm_encoder it's called right after the encoder's
355 	 * &drm_encoder_helper_funcs.atomic_disable hook.
356 	 *
357 	 * The bridge must assume that the display pipe (i.e. clocks and timing
358 	 * signals) feeding it is no longer running when this callback is
359 	 * called.
360 	 *
361 	 * The @atomic_post_disable callback is optional.
362 	 */
363 	void (*atomic_post_disable)(struct drm_bridge *bridge,
364 				    struct drm_bridge_state *old_bridge_state);
365 
366 	/**
367 	 * @atomic_duplicate_state:
368 	 *
369 	 * Duplicate the current bridge state object (which is guaranteed to be
370 	 * non-NULL).
371 	 *
372 	 * The atomic_duplicate_state hook is mandatory if the bridge
373 	 * implements any of the atomic hooks, and should be left unassigned
374 	 * otherwise. For bridges that don't subclass &drm_bridge_state, the
375 	 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
376 	 * used to implement this hook.
377 	 *
378 	 * RETURNS:
379 	 * A valid drm_bridge_state object or NULL if the allocation fails.
380 	 */
381 	struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
382 
383 	/**
384 	 * @atomic_destroy_state:
385 	 *
386 	 * Destroy a bridge state object previously allocated by
387 	 * &drm_bridge_funcs.atomic_duplicate_state().
388 	 *
389 	 * The atomic_destroy_state hook is mandatory if the bridge implements
390 	 * any of the atomic hooks, and should be left unassigned otherwise.
391 	 * For bridges that don't subclass &drm_bridge_state, the
392 	 * drm_atomic_helper_bridge_destroy_state() helper function shall be
393 	 * used to implement this hook.
394 	 */
395 	void (*atomic_destroy_state)(struct drm_bridge *bridge,
396 				     struct drm_bridge_state *state);
397 
398 	/**
399 	 * @atomic_get_output_bus_fmts:
400 	 *
401 	 * Return the supported bus formats on the output end of a bridge.
402 	 * The returned array must be allocated with kmalloc() and will be
403 	 * freed by the caller. If the allocation fails, NULL should be
404 	 * returned. num_output_fmts must be set to the returned array size.
405 	 * Formats listed in the returned array should be listed in decreasing
406 	 * preference order (the core will try all formats until it finds one
407 	 * that works).
408 	 *
409 	 * This method is only called on the last element of the bridge chain
410 	 * as part of the bus format negotiation process that happens in
411 	 * &drm_atomic_bridge_chain_select_bus_fmts().
412 	 * This method is optional. When not implemented, the core will
413 	 * fall back to &drm_connector.display_info.bus_formats[0] if
414 	 * &drm_connector.display_info.num_bus_formats > 0,
415 	 * or to MEDIA_BUS_FMT_FIXED otherwise.
416 	 */
417 	u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
418 					   struct drm_bridge_state *bridge_state,
419 					   struct drm_crtc_state *crtc_state,
420 					   struct drm_connector_state *conn_state,
421 					   unsigned int *num_output_fmts);
422 
423 	/**
424 	 * @atomic_get_input_bus_fmts:
425 	 *
426 	 * Return the supported bus formats on the input end of a bridge for
427 	 * a specific output bus format.
428 	 *
429 	 * The returned array must be allocated with kmalloc() and will be
430 	 * freed by the caller. If the allocation fails, NULL should be
431 	 * returned. num_input_fmts must be set to the returned array size.
432 	 * Formats listed in the returned array should be listed in decreasing
433 	 * preference order (the core will try all formats until it finds one
434 	 * that works). When the format is not supported NULL should be
435 	 * returned and num_input_fmts should be set to 0.
436 	 *
437 	 * This method is called on all elements of the bridge chain as part of
438 	 * the bus format negotiation process that happens in
439 	 * drm_atomic_bridge_chain_select_bus_fmts().
440 	 * This method is optional. When not implemented, the core will bypass
441 	 * bus format negotiation on this element of the bridge without
442 	 * failing, and the previous element in the chain will be passed
443 	 * MEDIA_BUS_FMT_FIXED as its output bus format.
444 	 *
445 	 * Bridge drivers that need to support being linked to bridges that are
446 	 * not supporting bus format negotiation should handle the
447 	 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
448 	 * sensible default value or extracting this information from somewhere
449 	 * else (FW property, &drm_display_mode, &drm_display_info, ...)
450 	 *
451 	 * Note: Even if input format selection on the first bridge has no
452 	 * impact on the negotiation process (bus format negotiation stops once
453 	 * we reach the first element of the chain), drivers are expected to
454 	 * return accurate input formats as the input format may be used to
455 	 * configure the CRTC output appropriately.
456 	 */
457 	u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
458 					  struct drm_bridge_state *bridge_state,
459 					  struct drm_crtc_state *crtc_state,
460 					  struct drm_connector_state *conn_state,
461 					  u32 output_fmt,
462 					  unsigned int *num_input_fmts);
463 
464 	/**
465 	 * @atomic_check:
466 	 *
467 	 * This method is responsible for checking bridge state correctness.
468 	 * It can also check the state of the surrounding components in chain
469 	 * to make sure the whole pipeline can work properly.
470 	 *
471 	 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
472 	 * order (from the last to the first bridge).
473 	 *
474 	 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
475 	 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
476 	 * one of them should be provided.
477 	 *
478 	 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
479 	 * &drm_bridge_state.output_bus_cfg.flags it should happen in
480 	 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
481 	 * field is set to the next bridge
482 	 * &drm_bridge_state.input_bus_cfg.flags value or
483 	 * &drm_connector.display_info.bus_flags if the bridge is the last
484 	 * element in the chain.
485 	 *
486 	 * RETURNS:
487 	 * zero if the check passed, a negative error code otherwise.
488 	 */
489 	int (*atomic_check)(struct drm_bridge *bridge,
490 			    struct drm_bridge_state *bridge_state,
491 			    struct drm_crtc_state *crtc_state,
492 			    struct drm_connector_state *conn_state);
493 
494 	/**
495 	 * @atomic_reset:
496 	 *
497 	 * Reset the bridge to a predefined state (or retrieve its current
498 	 * state) and return a &drm_bridge_state object matching this state.
499 	 * This function is called at attach time.
500 	 *
501 	 * The atomic_reset hook is mandatory if the bridge implements any of
502 	 * the atomic hooks, and should be left unassigned otherwise. For
503 	 * bridges that don't subclass &drm_bridge_state, the
504 	 * drm_atomic_helper_bridge_reset() helper function shall be used to
505 	 * implement this hook.
506 	 *
507 	 * Note that the atomic_reset() semantics is not exactly matching the
508 	 * reset() semantics found on other components (connector, plane, ...).
509 	 *
510 	 * 1. The reset operation happens when the bridge is attached, not when
511 	 *    drm_mode_config_reset() is called
512 	 * 2. It's meant to be used exclusively on bridges that have been
513 	 *    converted to the ATOMIC API
514 	 *
515 	 * RETURNS:
516 	 * A valid drm_bridge_state object in case of success, an ERR_PTR()
517 	 * giving the reason of the failure otherwise.
518 	 */
519 	struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
520 
521 	/**
522 	 * @detect:
523 	 *
524 	 * Check if anything is attached to the bridge output.
525 	 *
526 	 * This callback is optional, if not implemented the bridge will be
527 	 * considered as always having a component attached to its output.
528 	 * Bridges that implement this callback shall set the
529 	 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
530 	 *
531 	 * RETURNS:
532 	 *
533 	 * drm_connector_status indicating the bridge output status.
534 	 */
535 	enum drm_connector_status (*detect)(struct drm_bridge *bridge);
536 
537 	/**
538 	 * @get_modes:
539 	 *
540 	 * Fill all modes currently valid for the sink into the &drm_connector
541 	 * with drm_mode_probed_add().
542 	 *
543 	 * The @get_modes callback is mostly intended to support non-probeable
544 	 * displays such as many fixed panels. Bridges that support reading
545 	 * EDID shall leave @get_modes unimplemented and implement the
546 	 * &drm_bridge_funcs->edid_read callback instead.
547 	 *
548 	 * This callback is optional. Bridges that implement it shall set the
549 	 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
550 	 *
551 	 * The connector parameter shall be used for the sole purpose of
552 	 * filling modes, and shall not be stored internally by bridge drivers
553 	 * for future usage.
554 	 *
555 	 * RETURNS:
556 	 *
557 	 * The number of modes added by calling drm_mode_probed_add().
558 	 */
559 	int (*get_modes)(struct drm_bridge *bridge,
560 			 struct drm_connector *connector);
561 
562 	/**
563 	 * @edid_read:
564 	 *
565 	 * Read the EDID data of the connected display.
566 	 *
567 	 * The @edid_read callback is the preferred way of reporting mode
568 	 * information for a display connected to the bridge output. Bridges
569 	 * that support reading EDID shall implement this callback and leave
570 	 * the @get_modes callback unimplemented.
571 	 *
572 	 * The caller of this operation shall first verify the output
573 	 * connection status and refrain from reading EDID from a disconnected
574 	 * output.
575 	 *
576 	 * This callback is optional. Bridges that implement it shall set the
577 	 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
578 	 *
579 	 * The connector parameter shall be used for the sole purpose of EDID
580 	 * retrieval, and shall not be stored internally by bridge drivers for
581 	 * future usage.
582 	 *
583 	 * RETURNS:
584 	 *
585 	 * An edid structure newly allocated with drm_edid_alloc() or returned
586 	 * from drm_edid_read() family of functions on success, or NULL
587 	 * otherwise. The caller is responsible for freeing the returned edid
588 	 * structure with drm_edid_free().
589 	 */
590 	const struct drm_edid *(*edid_read)(struct drm_bridge *bridge,
591 					    struct drm_connector *connector);
592 
593 	/**
594 	 * @hpd_notify:
595 	 *
596 	 * Notify the bridge of hot plug detection.
597 	 *
598 	 * This callback is optional, it may be implemented by bridges that
599 	 * need to be notified of display connection or disconnection for
600 	 * internal reasons. One use case is to reset the internal state of CEC
601 	 * controllers for HDMI bridges.
602 	 */
603 	void (*hpd_notify)(struct drm_bridge *bridge,
604 			   enum drm_connector_status status);
605 
606 	/**
607 	 * @hpd_enable:
608 	 *
609 	 * Enable hot plug detection. From now on the bridge shall call
610 	 * drm_bridge_hpd_notify() each time a change is detected in the output
611 	 * connection status, until hot plug detection gets disabled with
612 	 * @hpd_disable.
613 	 *
614 	 * This callback is optional and shall only be implemented by bridges
615 	 * that support hot-plug notification without polling. Bridges that
616 	 * implement it shall also implement the @hpd_disable callback and set
617 	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
618 	 */
619 	void (*hpd_enable)(struct drm_bridge *bridge);
620 
621 	/**
622 	 * @hpd_disable:
623 	 *
624 	 * Disable hot plug detection. Once this function returns the bridge
625 	 * shall not call drm_bridge_hpd_notify() when a change in the output
626 	 * connection status occurs.
627 	 *
628 	 * This callback is optional and shall only be implemented by bridges
629 	 * that support hot-plug notification without polling. Bridges that
630 	 * implement it shall also implement the @hpd_enable callback and set
631 	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
632 	 */
633 	void (*hpd_disable)(struct drm_bridge *bridge);
634 
635 	/**
636 	 * @hdmi_tmds_char_rate_valid:
637 	 *
638 	 * Check whether a particular TMDS character rate is supported by the
639 	 * driver.
640 	 *
641 	 * This callback is optional and should only be implemented by the
642 	 * bridges that take part in the HDMI connector implementation. Bridges
643 	 * that implement it shall set the DRM_BRIDGE_OP_HDMI flag in their
644 	 * &drm_bridge->ops.
645 	 *
646 	 * Returns:
647 	 *
648 	 * Either &drm_mode_status.MODE_OK or one of the failure reasons
649 	 * in &enum drm_mode_status.
650 	 */
651 	enum drm_mode_status
652 	(*hdmi_tmds_char_rate_valid)(const struct drm_bridge *bridge,
653 				     const struct drm_display_mode *mode,
654 				     unsigned long long tmds_rate);
655 
656 	/**
657 	 * @hdmi_clear_infoframe:
658 	 *
659 	 * This callback clears the infoframes in the hardware during commit.
660 	 * It will be called multiple times, once for every disabled infoframe
661 	 * type.
662 	 *
663 	 * This callback is optional but it must be implemented by bridges that
664 	 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.
665 	 */
666 	int (*hdmi_clear_infoframe)(struct drm_bridge *bridge,
667 				    enum hdmi_infoframe_type type);
668 	/**
669 	 * @hdmi_write_infoframe:
670 	 *
671 	 * Program the infoframe into the hardware. It will be called multiple
672 	 * times, once for every updated infoframe type.
673 	 *
674 	 * This callback is optional but it must be implemented by bridges that
675 	 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.
676 	 */
677 	int (*hdmi_write_infoframe)(struct drm_bridge *bridge,
678 				    enum hdmi_infoframe_type type,
679 				    const u8 *buffer, size_t len);
680 
681 	/**
682 	 * @hdmi_audio_startup:
683 	 *
684 	 * Called when ASoC starts an audio stream setup. The
685 	 * @hdmi_audio_startup() is optional.
686 	 *
687 	 * Returns:
688 	 * 0 on success, a negative error code otherwise
689 	 */
690 	int (*hdmi_audio_startup)(struct drm_connector *connector,
691 				  struct drm_bridge *bridge);
692 
693 	/**
694 	 * @hdmi_audio_prepare:
695 	 * Configures HDMI-encoder for audio stream. Can be called multiple
696 	 * times for each setup. Mandatory if HDMI audio is enabled in the
697 	 * bridge's configuration.
698 	 *
699 	 * Returns:
700 	 * 0 on success, a negative error code otherwise
701 	 */
702 	int (*hdmi_audio_prepare)(struct drm_connector *connector,
703 				  struct drm_bridge *bridge,
704 				  struct hdmi_codec_daifmt *fmt,
705 				  struct hdmi_codec_params *hparms);
706 
707 	/**
708 	 * @hdmi_audio_shutdown:
709 	 *
710 	 * Shut down the audio stream. Mandatory if HDMI audio is enabled in
711 	 * the bridge's configuration.
712 	 *
713 	 * Returns:
714 	 * 0 on success, a negative error code otherwise
715 	 */
716 	void (*hdmi_audio_shutdown)(struct drm_connector *connector,
717 				    struct drm_bridge *bridge);
718 
719 	/**
720 	 * @hdmi_audio_mute_stream:
721 	 *
722 	 * Mute/unmute HDMI audio stream. The @hdmi_audio_mute_stream callback
723 	 * is optional.
724 	 *
725 	 * Returns:
726 	 * 0 on success, a negative error code otherwise
727 	 */
728 	int (*hdmi_audio_mute_stream)(struct drm_connector *connector,
729 				      struct drm_bridge *bridge,
730 				      bool enable, int direction);
731 
732 	/**
733 	 * @debugfs_init:
734 	 *
735 	 * Allows bridges to create bridge-specific debugfs files.
736 	 */
737 	void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);
738 };
739 
740 /**
741  * struct drm_bridge_timings - timing information for the bridge
742  */
743 struct drm_bridge_timings {
744 	/**
745 	 * @input_bus_flags:
746 	 *
747 	 * Tells what additional settings for the pixel data on the bus
748 	 * this bridge requires (like pixel signal polarity). See also
749 	 * &drm_display_info->bus_flags.
750 	 */
751 	u32 input_bus_flags;
752 	/**
753 	 * @setup_time_ps:
754 	 *
755 	 * Defines the time in picoseconds the input data lines must be
756 	 * stable before the clock edge.
757 	 */
758 	u32 setup_time_ps;
759 	/**
760 	 * @hold_time_ps:
761 	 *
762 	 * Defines the time in picoseconds taken for the bridge to sample the
763 	 * input signal after the clock edge.
764 	 */
765 	u32 hold_time_ps;
766 	/**
767 	 * @dual_link:
768 	 *
769 	 * True if the bus operates in dual-link mode. The exact meaning is
770 	 * dependent on the bus type. For LVDS buses, this indicates that even-
771 	 * and odd-numbered pixels are received on separate links.
772 	 */
773 	bool dual_link;
774 };
775 
776 /**
777  * enum drm_bridge_ops - Bitmask of operations supported by the bridge
778  */
779 enum drm_bridge_ops {
780 	/**
781 	 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
782 	 * its output. Bridges that set this flag shall implement the
783 	 * &drm_bridge_funcs->detect callback.
784 	 */
785 	DRM_BRIDGE_OP_DETECT = BIT(0),
786 	/**
787 	 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
788 	 * connected to its output. Bridges that set this flag shall implement
789 	 * the &drm_bridge_funcs->edid_read callback.
790 	 */
791 	DRM_BRIDGE_OP_EDID = BIT(1),
792 	/**
793 	 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
794 	 * without requiring polling. Bridges that set this flag shall
795 	 * implement the &drm_bridge_funcs->hpd_enable and
796 	 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
797 	 * and disabling hot-plug detection dynamically.
798 	 */
799 	DRM_BRIDGE_OP_HPD = BIT(2),
800 	/**
801 	 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
802 	 * by the display at its output. This does not include reading EDID
803 	 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
804 	 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
805 	 */
806 	DRM_BRIDGE_OP_MODES = BIT(3),
807 	/**
808 	 * @DRM_BRIDGE_OP_HDMI: The bridge provides HDMI connector operations,
809 	 * including infoframes support. Bridges that set this flag must
810 	 * implement the &drm_bridge_funcs->write_infoframe callback.
811 	 *
812 	 * Note: currently there can be at most one bridge in a chain that sets
813 	 * this bit. This is to simplify corresponding glue code in connector
814 	 * drivers.
815 	 */
816 	DRM_BRIDGE_OP_HDMI = BIT(4),
817 };
818 
819 /**
820  * struct drm_bridge - central DRM bridge control structure
821  */
822 struct drm_bridge {
823 	/** @base: inherit from &drm_private_object */
824 	struct drm_private_obj base;
825 	/** @dev: DRM device this bridge belongs to */
826 	struct drm_device *dev;
827 	/** @encoder: encoder to which this bridge is connected */
828 	struct drm_encoder *encoder;
829 	/** @chain_node: used to form a bridge chain */
830 	struct list_head chain_node;
831 	/** @of_node: device node pointer to the bridge */
832 	struct device_node *of_node;
833 	/** @list: to keep track of all added bridges */
834 	struct list_head list;
835 	/**
836 	 * @timings:
837 	 *
838 	 * the timing specification for the bridge, if any (may be NULL)
839 	 */
840 	const struct drm_bridge_timings *timings;
841 	/** @funcs: control functions */
842 	const struct drm_bridge_funcs *funcs;
843 	/** @driver_private: pointer to the bridge driver's internal context */
844 	void *driver_private;
845 	/** @ops: bitmask of operations supported by the bridge */
846 	enum drm_bridge_ops ops;
847 	/**
848 	 * @type: Type of the connection at the bridge output
849 	 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
850 	 * identifies the type of connected display.
851 	 */
852 	int type;
853 	/**
854 	 * @interlace_allowed: Indicate that the bridge can handle interlaced
855 	 * modes.
856 	 */
857 	bool interlace_allowed;
858 	/**
859 	 * @ycbcr_420_allowed: Indicate that the bridge can handle YCbCr 420
860 	 * output.
861 	 */
862 	bool ycbcr_420_allowed;
863 	/**
864 	 * @pre_enable_prev_first: The bridge requires that the prev
865 	 * bridge @pre_enable function is called before its @pre_enable,
866 	 * and conversely for post_disable. This is most frequently a
867 	 * requirement for DSI devices which need the host to be initialised
868 	 * before the peripheral.
869 	 */
870 	bool pre_enable_prev_first;
871 	/**
872 	 * @ddc: Associated I2C adapter for DDC access, if any.
873 	 */
874 	struct i2c_adapter *ddc;
875 	/** private: */
876 	/**
877 	 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
878 	 */
879 	struct mutex hpd_mutex;
880 	/**
881 	 * @hpd_cb: Hot plug detection callback, registered with
882 	 * drm_bridge_hpd_enable().
883 	 */
884 	void (*hpd_cb)(void *data, enum drm_connector_status status);
885 	/**
886 	 * @hpd_data: Private data passed to the Hot plug detection callback
887 	 * @hpd_cb.
888 	 */
889 	void *hpd_data;
890 
891 	/**
892 	 * @vendor: Vendor of the product to be used for the SPD InfoFrame
893 	 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.
894 	 */
895 	const char *vendor;
896 
897 	/**
898 	 * @product: Name of the product to be used for the SPD InfoFrame
899 	 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.
900 	 */
901 	const char *product;
902 
903 	/**
904 	 * @supported_formats: Bitmask of @hdmi_colorspace listing supported
905 	 * output formats. This is only relevant if @DRM_BRIDGE_OP_HDMI is set.
906 	 */
907 	unsigned int supported_formats;
908 
909 	/**
910 	 * @max_bpc: Maximum bits per char the HDMI bridge supports. Allowed
911 	 * values are 8, 10 and 12. This is only relevant if
912 	 * @DRM_BRIDGE_OP_HDMI is set.
913 	 */
914 	unsigned int max_bpc;
915 
916 	/**
917 	 * @hdmi_audio_dev: device to be used as a parent for the HDMI Codec
918 	 */
919 	struct device *hdmi_audio_dev;
920 
921 	/**
922 	 * @hdmi_audio_max_i2s_playback_channels: maximum number of playback
923 	 * I2S channels for the HDMI codec
924 	 */
925 	int hdmi_audio_max_i2s_playback_channels;
926 
927 	/**
928 	 * @hdmi_audio_spdif_playback: set if HDMI codec has S/PDIF playback port
929 	 */
930 	unsigned int hdmi_audio_spdif_playback : 1;
931 
932 	/**
933 	 * @hdmi_audio_dai_port: sound DAI port, -1 if it is not enabled
934 	 */
935 	int hdmi_audio_dai_port;
936 };
937 
938 static inline struct drm_bridge *
drm_priv_to_bridge(struct drm_private_obj * priv)939 drm_priv_to_bridge(struct drm_private_obj *priv)
940 {
941 	return container_of(priv, struct drm_bridge, base);
942 }
943 
944 void drm_bridge_add(struct drm_bridge *bridge);
945 int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
946 void drm_bridge_remove(struct drm_bridge *bridge);
947 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
948 		      struct drm_bridge *previous,
949 		      enum drm_bridge_attach_flags flags);
950 
951 #ifdef CONFIG_OF
952 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
953 #else
of_drm_find_bridge(struct device_node * np)954 static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
955 {
956 	return NULL;
957 }
958 #endif
959 
960 /**
961  * drm_bridge_get_next_bridge() - Get the next bridge in the chain
962  * @bridge: bridge object
963  *
964  * RETURNS:
965  * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
966  */
967 static inline struct drm_bridge *
drm_bridge_get_next_bridge(struct drm_bridge * bridge)968 drm_bridge_get_next_bridge(struct drm_bridge *bridge)
969 {
970 	if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
971 		return NULL;
972 
973 	return list_next_entry(bridge, chain_node);
974 }
975 
976 /**
977  * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
978  * @bridge: bridge object
979  *
980  * RETURNS:
981  * the previous bridge in the chain, or NULL if @bridge is the first.
982  */
983 static inline struct drm_bridge *
drm_bridge_get_prev_bridge(struct drm_bridge * bridge)984 drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
985 {
986 	if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
987 		return NULL;
988 
989 	return list_prev_entry(bridge, chain_node);
990 }
991 
992 /**
993  * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
994  * @encoder: encoder object
995  *
996  * RETURNS:
997  * the first bridge in the chain, or NULL if @encoder has no bridge attached
998  * to it.
999  */
1000 static inline struct drm_bridge *
drm_bridge_chain_get_first_bridge(struct drm_encoder * encoder)1001 drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
1002 {
1003 	return list_first_entry_or_null(&encoder->bridge_chain,
1004 					struct drm_bridge, chain_node);
1005 }
1006 
1007 /**
1008  * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
1009  * @encoder: the encoder to iterate bridges on
1010  * @bridge: a bridge pointer updated to point to the current bridge at each
1011  *	    iteration
1012  *
1013  * Iterate over all bridges present in the bridge chain attached to @encoder.
1014  */
1015 #define drm_for_each_bridge_in_chain(encoder, bridge)			\
1016 	list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
1017 
1018 enum drm_mode_status
1019 drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
1020 			    const struct drm_display_info *info,
1021 			    const struct drm_display_mode *mode);
1022 void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
1023 			       const struct drm_display_mode *mode,
1024 			       const struct drm_display_mode *adjusted_mode);
1025 
1026 int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
1027 				  struct drm_crtc_state *crtc_state,
1028 				  struct drm_connector_state *conn_state);
1029 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
1030 				     struct drm_atomic_state *state);
1031 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
1032 					  struct drm_atomic_state *state);
1033 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
1034 					struct drm_atomic_state *state);
1035 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
1036 				    struct drm_atomic_state *state);
1037 
1038 u32 *
1039 drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
1040 					struct drm_bridge_state *bridge_state,
1041 					struct drm_crtc_state *crtc_state,
1042 					struct drm_connector_state *conn_state,
1043 					u32 output_fmt,
1044 					unsigned int *num_input_fmts);
1045 
1046 enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
1047 int drm_bridge_get_modes(struct drm_bridge *bridge,
1048 			 struct drm_connector *connector);
1049 const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge,
1050 					    struct drm_connector *connector);
1051 void drm_bridge_hpd_enable(struct drm_bridge *bridge,
1052 			   void (*cb)(void *data,
1053 				      enum drm_connector_status status),
1054 			   void *data);
1055 void drm_bridge_hpd_disable(struct drm_bridge *bridge);
1056 void drm_bridge_hpd_notify(struct drm_bridge *bridge,
1057 			   enum drm_connector_status status);
1058 
1059 #ifdef CONFIG_DRM_PANEL_BRIDGE
1060 bool drm_bridge_is_panel(const struct drm_bridge *bridge);
1061 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
1062 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
1063 					      u32 connector_type);
1064 void drm_panel_bridge_remove(struct drm_bridge *bridge);
1065 int drm_panel_bridge_set_orientation(struct drm_connector *connector,
1066 				     struct drm_bridge *bridge);
1067 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
1068 					     struct drm_panel *panel);
1069 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
1070 						   struct drm_panel *panel,
1071 						   u32 connector_type);
1072 struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,
1073 					     struct drm_panel *panel);
1074 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
1075 #else
drm_bridge_is_panel(const struct drm_bridge * bridge)1076 static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)
1077 {
1078 	return false;
1079 }
1080 
drm_panel_bridge_set_orientation(struct drm_connector * connector,struct drm_bridge * bridge)1081 static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,
1082 						   struct drm_bridge *bridge)
1083 {
1084 	return -EINVAL;
1085 }
1086 #endif
1087 
1088 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)
1089 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,
1090 					  u32 port, u32 endpoint);
1091 struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,
1092 					  u32 port, u32 endpoint);
1093 #else
devm_drm_of_get_bridge(struct device * dev,struct device_node * node,u32 port,u32 endpoint)1094 static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
1095 							struct device_node *node,
1096 							u32 port,
1097 							u32 endpoint)
1098 {
1099 	return ERR_PTR(-ENODEV);
1100 }
1101 
drmm_of_get_bridge(struct drm_device * drm,struct device_node * node,u32 port,u32 endpoint)1102 static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
1103 						     struct device_node *node,
1104 						     u32 port,
1105 						     u32 endpoint)
1106 {
1107 	return ERR_PTR(-ENODEV);
1108 }
1109 #endif
1110 
1111 #endif
1112