xref: /linux/drivers/gpu/drm/display/drm_bridge_connector.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2019 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
4  */
5 
6 #include <linux/export.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/property.h>
11 #include <linux/slab.h>
12 
13 #include <drm/drm_atomic_state_helper.h>
14 #include <drm/drm_bridge.h>
15 #include <drm/drm_bridge_connector.h>
16 #include <drm/drm_connector.h>
17 #include <drm/drm_device.h>
18 #include <drm/drm_edid.h>
19 #include <drm/drm_managed.h>
20 #include <drm/drm_modeset_helper_vtables.h>
21 #include <drm/drm_print.h>
22 #include <drm/drm_probe_helper.h>
23 #include <drm/display/drm_hdcp_helper.h>
24 #include <drm/display/drm_hdmi_audio_helper.h>
25 #include <drm/display/drm_hdmi_cec_helper.h>
26 #include <drm/display/drm_hdmi_helper.h>
27 #include <drm/display/drm_hdmi_state_helper.h>
28 
29 /**
30  * DOC: overview
31  *
32  * The DRM bridge connector helper object provides a DRM connector
33  * implementation that wraps a chain of &struct drm_bridge. The connector
34  * operations are fully implemented based on the operations of the bridges in
35  * the chain, and don't require any intervention from the display controller
36  * driver at runtime.
37  *
38  * To use the helper, display controller drivers create a bridge connector with
39  * a call to drm_bridge_connector_init(). This associates the newly created
40  * connector with the chain of bridges passed to the function and registers it
41  * with the DRM device. At that point the connector becomes fully usable, no
42  * further operation is needed.
43  *
44  * The DRM bridge connector operations are implemented based on the operations
45  * provided by the bridges in the chain. Each connector operation is delegated
46  * to the bridge closest to the connector (at the end of the chain) that
47  * provides the relevant functionality.
48  *
49  * To make use of this helper, all bridges in the chain shall report bridge
50  * operation flags (&drm_bridge->ops) and bridge output type
51  * (&drm_bridge->type), as well as the DRM_BRIDGE_ATTACH_NO_CONNECTOR attach
52  * flag (none of the bridges shall create a DRM connector directly).
53  */
54 
55 /**
56  * struct drm_bridge_connector - A connector backed by a chain of bridges
57  */
58 struct drm_bridge_connector {
59 	/**
60 	 * @base: The base DRM connector
61 	 */
62 	struct drm_connector base;
63 	/**
64 	 * @encoder:
65 	 *
66 	 * The encoder at the start of the bridges chain.
67 	 */
68 	struct drm_encoder *encoder;
69 	/**
70 	 * @bridge_edid:
71 	 *
72 	 * The last bridge in the chain (closest to the connector) that provides
73 	 * EDID read support, if any (see &DRM_BRIDGE_OP_EDID).
74 	 */
75 	struct drm_bridge *bridge_edid;
76 	/**
77 	 * @bridge_hpd:
78 	 *
79 	 * The last bridge in the chain (closest to the connector) that provides
80 	 * hot-plug detection notification, if any (see &DRM_BRIDGE_OP_HPD).
81 	 */
82 	struct drm_bridge *bridge_hpd;
83 	/**
84 	 * @bridge_detect:
85 	 *
86 	 * The last bridge in the chain (closest to the connector) that provides
87 	 * connector detection, if any (see &DRM_BRIDGE_OP_DETECT).
88 	 */
89 	struct drm_bridge *bridge_detect;
90 	/**
91 	 * @bridge_modes:
92 	 *
93 	 * The last bridge in the chain (closest to the connector) that provides
94 	 * connector modes detection, if any (see &DRM_BRIDGE_OP_MODES).
95 	 */
96 	struct drm_bridge *bridge_modes;
97 	/**
98 	 * @bridge_hdmi:
99 	 *
100 	 * The bridge in the chain that implements necessary support for the
101 	 * HDMI connector infrastructure, if any (see &DRM_BRIDGE_OP_HDMI).
102 	 */
103 	struct drm_bridge *bridge_hdmi;
104 	/**
105 	 * @bridge_hdmi_audio:
106 	 *
107 	 * The bridge in the chain that implements necessary support for the
108 	 * HDMI Audio infrastructure, if any (see &DRM_BRIDGE_OP_HDMI_AUDIO).
109 	 */
110 	struct drm_bridge *bridge_hdmi_audio;
111 	/**
112 	 * @bridge_dp_audio:
113 	 *
114 	 * The bridge in the chain that implements necessary support for the
115 	 * DisplayPort Audio infrastructure, if any (see
116 	 * &DRM_BRIDGE_OP_DP_AUDIO).
117 	 */
118 	struct drm_bridge *bridge_dp_audio;
119 	/**
120 	 * @bridge_hdmi_cec:
121 	 *
122 	 * The bridge in the chain that implements CEC support, if any (see
123 	 * DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER).
124 	 */
125 	struct drm_bridge *bridge_hdmi_cec;
126 };
127 
128 #define to_drm_bridge_connector(x) \
129 	container_of(x, struct drm_bridge_connector, base)
130 
131 /* -----------------------------------------------------------------------------
132  * Bridge Connector Hot-Plug Handling
133  */
134 
135 static void drm_bridge_connector_hpd_notify(struct drm_connector *connector,
136 					    enum drm_connector_status status)
137 {
138 	struct drm_bridge_connector *bridge_connector =
139 		to_drm_bridge_connector(connector);
140 	struct drm_bridge *bridge;
141 
142 	/* Notify all bridges in the pipeline of hotplug events. */
143 	drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge) {
144 		if (bridge->funcs->hpd_notify)
145 			bridge->funcs->hpd_notify(bridge, status);
146 	}
147 }
148 
149 static void drm_bridge_connector_handle_hpd(struct drm_bridge_connector *drm_bridge_connector,
150 					    enum drm_connector_status status)
151 {
152 	struct drm_connector *connector = &drm_bridge_connector->base;
153 	struct drm_device *dev = connector->dev;
154 
155 	mutex_lock(&dev->mode_config.mutex);
156 	connector->status = status;
157 	mutex_unlock(&dev->mode_config.mutex);
158 
159 	drm_bridge_connector_hpd_notify(connector, status);
160 
161 	drm_kms_helper_connector_hotplug_event(connector);
162 }
163 
164 static void drm_bridge_connector_hpd_cb(void *cb_data,
165 					enum drm_connector_status status)
166 {
167 	drm_bridge_connector_handle_hpd(cb_data, status);
168 }
169 
170 static void drm_bridge_connector_oob_hotplug_event(struct drm_connector *connector,
171 						   enum drm_connector_status status)
172 {
173 	struct drm_bridge_connector *bridge_connector =
174 		to_drm_bridge_connector(connector);
175 
176 	drm_bridge_connector_handle_hpd(bridge_connector, status);
177 }
178 
179 static void drm_bridge_connector_enable_hpd(struct drm_connector *connector)
180 {
181 	struct drm_bridge_connector *bridge_connector =
182 		to_drm_bridge_connector(connector);
183 	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
184 
185 	if (hpd)
186 		drm_bridge_hpd_enable(hpd, drm_bridge_connector_hpd_cb,
187 				      bridge_connector);
188 }
189 
190 static void drm_bridge_connector_disable_hpd(struct drm_connector *connector)
191 {
192 	struct drm_bridge_connector *bridge_connector =
193 		to_drm_bridge_connector(connector);
194 	struct drm_bridge *hpd = bridge_connector->bridge_hpd;
195 
196 	if (hpd)
197 		drm_bridge_hpd_disable(hpd);
198 }
199 
200 /* -----------------------------------------------------------------------------
201  * Bridge Connector Functions
202  */
203 
204 static enum drm_connector_status
205 drm_bridge_connector_detect(struct drm_connector *connector, bool force)
206 {
207 	struct drm_bridge_connector *bridge_connector =
208 		to_drm_bridge_connector(connector);
209 	struct drm_bridge *detect = bridge_connector->bridge_detect;
210 	struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
211 	enum drm_connector_status status;
212 
213 	if (detect) {
214 		status = detect->funcs->detect(detect, connector);
215 
216 		if (hdmi)
217 			drm_atomic_helper_connector_hdmi_hotplug(connector, status);
218 
219 		drm_bridge_connector_hpd_notify(connector, status);
220 	} else {
221 		switch (connector->connector_type) {
222 		case DRM_MODE_CONNECTOR_DPI:
223 		case DRM_MODE_CONNECTOR_LVDS:
224 		case DRM_MODE_CONNECTOR_DSI:
225 		case DRM_MODE_CONNECTOR_eDP:
226 			status = connector_status_connected;
227 			break;
228 		default:
229 			status = connector_status_unknown;
230 			break;
231 		}
232 	}
233 
234 	return status;
235 }
236 
237 static void drm_bridge_connector_force(struct drm_connector *connector)
238 {
239 	struct drm_bridge_connector *bridge_connector =
240 		to_drm_bridge_connector(connector);
241 	struct drm_bridge *hdmi = bridge_connector->bridge_hdmi;
242 
243 	if (hdmi)
244 		drm_atomic_helper_connector_hdmi_force(connector);
245 }
246 
247 static void drm_bridge_connector_debugfs_init(struct drm_connector *connector,
248 					      struct dentry *root)
249 {
250 	struct drm_bridge_connector *bridge_connector =
251 		to_drm_bridge_connector(connector);
252 	struct drm_encoder *encoder = bridge_connector->encoder;
253 	struct drm_bridge *bridge;
254 
255 	list_for_each_entry(bridge, &encoder->bridge_chain, chain_node) {
256 		if (bridge->funcs->debugfs_init)
257 			bridge->funcs->debugfs_init(bridge, root);
258 	}
259 }
260 
261 static void drm_bridge_connector_reset(struct drm_connector *connector)
262 {
263 	struct drm_bridge_connector *bridge_connector =
264 		to_drm_bridge_connector(connector);
265 
266 	drm_atomic_helper_connector_reset(connector);
267 	if (bridge_connector->bridge_hdmi)
268 		__drm_atomic_helper_connector_hdmi_reset(connector,
269 							 connector->state);
270 }
271 
272 static const struct drm_connector_funcs drm_bridge_connector_funcs = {
273 	.reset = drm_bridge_connector_reset,
274 	.detect = drm_bridge_connector_detect,
275 	.force = drm_bridge_connector_force,
276 	.fill_modes = drm_helper_probe_single_connector_modes,
277 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
278 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
279 	.debugfs_init = drm_bridge_connector_debugfs_init,
280 	.oob_hotplug_event = drm_bridge_connector_oob_hotplug_event,
281 };
282 
283 /* -----------------------------------------------------------------------------
284  * Bridge Connector Helper Functions
285  */
286 
287 static int drm_bridge_connector_get_modes_edid(struct drm_connector *connector,
288 					       struct drm_bridge *bridge)
289 {
290 	enum drm_connector_status status;
291 	const struct drm_edid *drm_edid;
292 	int n;
293 
294 	status = drm_bridge_connector_detect(connector, false);
295 	if (status != connector_status_connected)
296 		goto no_edid;
297 
298 	drm_edid = drm_bridge_edid_read(bridge, connector);
299 	if (!drm_edid_valid(drm_edid)) {
300 		drm_edid_free(drm_edid);
301 		goto no_edid;
302 	}
303 
304 	drm_edid_connector_update(connector, drm_edid);
305 	n = drm_edid_connector_add_modes(connector);
306 
307 	drm_edid_free(drm_edid);
308 	return n;
309 
310 no_edid:
311 	drm_edid_connector_update(connector, NULL);
312 	return 0;
313 }
314 
315 static int drm_bridge_connector_get_modes(struct drm_connector *connector)
316 {
317 	struct drm_bridge_connector *bridge_connector =
318 		to_drm_bridge_connector(connector);
319 	struct drm_bridge *bridge;
320 
321 	/*
322 	 * If there is a HDMI bridge, EDID has been updated as a part of
323 	 * the .detect(). Just update the modes here.
324 	 */
325 	bridge = bridge_connector->bridge_hdmi;
326 	if (bridge)
327 		return drm_edid_connector_add_modes(connector);
328 
329 	/*
330 	 * If display exposes EDID, then we parse that in the normal way to
331 	 * build table of supported modes.
332 	 */
333 	bridge = bridge_connector->bridge_edid;
334 	if (bridge)
335 		return drm_bridge_connector_get_modes_edid(connector, bridge);
336 
337 	/*
338 	 * Otherwise if the display pipeline reports modes (e.g. with a fixed
339 	 * resolution panel or an analog TV output), query it.
340 	 */
341 	bridge = bridge_connector->bridge_modes;
342 	if (bridge)
343 		return bridge->funcs->get_modes(bridge, connector);
344 
345 	/*
346 	 * We can't retrieve modes, which can happen for instance for a DVI or
347 	 * VGA output with the DDC bus unconnected. The KMS core will add the
348 	 * default modes.
349 	 */
350 	return 0;
351 }
352 
353 static enum drm_mode_status
354 drm_bridge_connector_mode_valid(struct drm_connector *connector,
355 				const struct drm_display_mode *mode)
356 {
357 	struct drm_bridge_connector *bridge_connector =
358 		to_drm_bridge_connector(connector);
359 
360 	if (bridge_connector->bridge_hdmi)
361 		return drm_hdmi_connector_mode_valid(connector, mode);
362 
363 	return MODE_OK;
364 }
365 
366 static int drm_bridge_connector_atomic_check(struct drm_connector *connector,
367 					     struct drm_atomic_state *state)
368 {
369 	struct drm_bridge_connector *bridge_connector =
370 		to_drm_bridge_connector(connector);
371 
372 	if (bridge_connector->bridge_hdmi)
373 		return drm_atomic_helper_connector_hdmi_check(connector, state);
374 
375 	return 0;
376 }
377 
378 static const struct drm_connector_helper_funcs drm_bridge_connector_helper_funcs = {
379 	.get_modes = drm_bridge_connector_get_modes,
380 	.mode_valid = drm_bridge_connector_mode_valid,
381 	.enable_hpd = drm_bridge_connector_enable_hpd,
382 	.disable_hpd = drm_bridge_connector_disable_hpd,
383 	.atomic_check = drm_bridge_connector_atomic_check,
384 };
385 
386 static enum drm_mode_status
387 drm_bridge_connector_tmds_char_rate_valid(const struct drm_connector *connector,
388 					  const struct drm_display_mode *mode,
389 					  unsigned long long tmds_rate)
390 {
391 	struct drm_bridge_connector *bridge_connector =
392 		to_drm_bridge_connector(connector);
393 	struct drm_bridge *bridge;
394 
395 	bridge = bridge_connector->bridge_hdmi;
396 	if (!bridge)
397 		return MODE_ERROR;
398 
399 	if (bridge->funcs->hdmi_tmds_char_rate_valid)
400 		return bridge->funcs->hdmi_tmds_char_rate_valid(bridge, mode, tmds_rate);
401 	else
402 		return MODE_OK;
403 }
404 
405 static int drm_bridge_connector_clear_infoframe(struct drm_connector *connector,
406 						enum hdmi_infoframe_type type)
407 {
408 	struct drm_bridge_connector *bridge_connector =
409 		to_drm_bridge_connector(connector);
410 	struct drm_bridge *bridge;
411 
412 	bridge = bridge_connector->bridge_hdmi;
413 	if (!bridge)
414 		return -EINVAL;
415 
416 	return bridge->funcs->hdmi_clear_infoframe(bridge, type);
417 }
418 
419 static int drm_bridge_connector_write_infoframe(struct drm_connector *connector,
420 						enum hdmi_infoframe_type type,
421 						const u8 *buffer, size_t len)
422 {
423 	struct drm_bridge_connector *bridge_connector =
424 		to_drm_bridge_connector(connector);
425 	struct drm_bridge *bridge;
426 
427 	bridge = bridge_connector->bridge_hdmi;
428 	if (!bridge)
429 		return -EINVAL;
430 
431 	return bridge->funcs->hdmi_write_infoframe(bridge, type, buffer, len);
432 }
433 
434 static const struct drm_edid *
435 drm_bridge_connector_read_edid(struct drm_connector *connector)
436 {
437 	struct drm_bridge_connector *bridge_connector =
438 		to_drm_bridge_connector(connector);
439 	struct drm_bridge *bridge;
440 
441 	bridge = bridge_connector->bridge_edid;
442 	if (!bridge)
443 		return NULL;
444 
445 	return drm_bridge_edid_read(bridge, connector);
446 }
447 
448 static const struct drm_connector_hdmi_funcs drm_bridge_connector_hdmi_funcs = {
449 	.tmds_char_rate_valid = drm_bridge_connector_tmds_char_rate_valid,
450 	.clear_infoframe = drm_bridge_connector_clear_infoframe,
451 	.write_infoframe = drm_bridge_connector_write_infoframe,
452 	.read_edid = drm_bridge_connector_read_edid,
453 };
454 
455 static int drm_bridge_connector_audio_startup(struct drm_connector *connector)
456 {
457 	struct drm_bridge_connector *bridge_connector =
458 		to_drm_bridge_connector(connector);
459 	struct drm_bridge *bridge;
460 
461 	if (bridge_connector->bridge_hdmi_audio) {
462 		bridge = bridge_connector->bridge_hdmi_audio;
463 
464 		if (!bridge->funcs->hdmi_audio_startup)
465 			return 0;
466 
467 		return bridge->funcs->hdmi_audio_startup(bridge, connector);
468 	}
469 
470 	if (bridge_connector->bridge_dp_audio) {
471 		bridge = bridge_connector->bridge_dp_audio;
472 
473 		if (!bridge->funcs->dp_audio_startup)
474 			return 0;
475 
476 		return bridge->funcs->dp_audio_startup(bridge, connector);
477 	}
478 
479 	return -EINVAL;
480 }
481 
482 static int drm_bridge_connector_audio_prepare(struct drm_connector *connector,
483 					      struct hdmi_codec_daifmt *fmt,
484 					      struct hdmi_codec_params *hparms)
485 {
486 	struct drm_bridge_connector *bridge_connector =
487 		to_drm_bridge_connector(connector);
488 	struct drm_bridge *bridge;
489 
490 	if (bridge_connector->bridge_hdmi_audio) {
491 		bridge = bridge_connector->bridge_hdmi_audio;
492 
493 		return bridge->funcs->hdmi_audio_prepare(bridge, connector, fmt, hparms);
494 	}
495 
496 	if (bridge_connector->bridge_dp_audio) {
497 		bridge = bridge_connector->bridge_dp_audio;
498 
499 		return bridge->funcs->dp_audio_prepare(bridge, connector, fmt, hparms);
500 	}
501 
502 	return -EINVAL;
503 }
504 
505 static void drm_bridge_connector_audio_shutdown(struct drm_connector *connector)
506 {
507 	struct drm_bridge_connector *bridge_connector =
508 		to_drm_bridge_connector(connector);
509 	struct drm_bridge *bridge;
510 
511 	if (bridge_connector->bridge_hdmi_audio) {
512 		bridge = bridge_connector->bridge_hdmi_audio;
513 		bridge->funcs->hdmi_audio_shutdown(bridge, connector);
514 	}
515 
516 	if (bridge_connector->bridge_dp_audio) {
517 		bridge = bridge_connector->bridge_dp_audio;
518 		bridge->funcs->dp_audio_shutdown(bridge, connector);
519 	}
520 }
521 
522 static int drm_bridge_connector_audio_mute_stream(struct drm_connector *connector,
523 						  bool enable, int direction)
524 {
525 	struct drm_bridge_connector *bridge_connector =
526 		to_drm_bridge_connector(connector);
527 	struct drm_bridge *bridge;
528 
529 	if (bridge_connector->bridge_hdmi_audio) {
530 		bridge = bridge_connector->bridge_hdmi_audio;
531 
532 		if (!bridge->funcs->hdmi_audio_mute_stream)
533 			return -ENOTSUPP;
534 
535 		return bridge->funcs->hdmi_audio_mute_stream(bridge, connector,
536 							     enable, direction);
537 	}
538 
539 	if (bridge_connector->bridge_dp_audio) {
540 		bridge = bridge_connector->bridge_dp_audio;
541 
542 		if (!bridge->funcs->dp_audio_mute_stream)
543 			return -ENOTSUPP;
544 
545 		return bridge->funcs->dp_audio_mute_stream(bridge, connector,
546 							   enable, direction);
547 	}
548 
549 	return -EINVAL;
550 }
551 
552 static const struct drm_connector_hdmi_audio_funcs drm_bridge_connector_hdmi_audio_funcs = {
553 	.startup = drm_bridge_connector_audio_startup,
554 	.prepare = drm_bridge_connector_audio_prepare,
555 	.shutdown = drm_bridge_connector_audio_shutdown,
556 	.mute_stream = drm_bridge_connector_audio_mute_stream,
557 };
558 
559 static int drm_bridge_connector_hdmi_cec_enable(struct drm_connector *connector, bool enable)
560 {
561 	struct drm_bridge_connector *bridge_connector =
562 		to_drm_bridge_connector(connector);
563 	struct drm_bridge *bridge;
564 
565 	bridge = bridge_connector->bridge_hdmi_cec;
566 
567 	return bridge->funcs->hdmi_cec_enable(bridge, enable);
568 }
569 
570 static int drm_bridge_connector_hdmi_cec_log_addr(struct drm_connector *connector, u8 logical_addr)
571 {
572 	struct drm_bridge_connector *bridge_connector =
573 		to_drm_bridge_connector(connector);
574 	struct drm_bridge *bridge;
575 
576 	bridge = bridge_connector->bridge_hdmi_cec;
577 
578 	return bridge->funcs->hdmi_cec_log_addr(bridge, logical_addr);
579 }
580 
581 static int drm_bridge_connector_hdmi_cec_transmit(struct drm_connector *connector,
582 						  u8 attempts,
583 						  u32 signal_free_time,
584 						  struct cec_msg *msg)
585 {
586 	struct drm_bridge_connector *bridge_connector =
587 		to_drm_bridge_connector(connector);
588 	struct drm_bridge *bridge;
589 
590 	bridge = bridge_connector->bridge_hdmi_cec;
591 
592 	return bridge->funcs->hdmi_cec_transmit(bridge, attempts,
593 						signal_free_time,
594 						msg);
595 }
596 
597 static int drm_bridge_connector_hdmi_cec_init(struct drm_connector *connector)
598 {
599 	struct drm_bridge_connector *bridge_connector =
600 		to_drm_bridge_connector(connector);
601 	struct drm_bridge *bridge;
602 
603 	bridge = bridge_connector->bridge_hdmi_cec;
604 
605 	if (!bridge->funcs->hdmi_cec_init)
606 		return 0;
607 
608 	return bridge->funcs->hdmi_cec_init(bridge, connector);
609 }
610 
611 static const struct drm_connector_hdmi_cec_funcs drm_bridge_connector_hdmi_cec_funcs = {
612 	.init = drm_bridge_connector_hdmi_cec_init,
613 	.enable = drm_bridge_connector_hdmi_cec_enable,
614 	.log_addr = drm_bridge_connector_hdmi_cec_log_addr,
615 	.transmit = drm_bridge_connector_hdmi_cec_transmit,
616 };
617 
618 /* -----------------------------------------------------------------------------
619  * Bridge Connector Initialisation
620  */
621 
622 /**
623  * drm_bridge_connector_init - Initialise a connector for a chain of bridges
624  * @drm: the DRM device
625  * @encoder: the encoder where the bridge chain starts
626  *
627  * Allocate, initialise and register a &drm_bridge_connector with the @drm
628  * device. The connector is associated with a chain of bridges that starts at
629  * the @encoder. All bridges in the chain shall report bridge operation flags
630  * (&drm_bridge->ops) and bridge output type (&drm_bridge->type), and none of
631  * them may create a DRM connector directly.
632  *
633  * Returns a pointer to the new connector on success, or a negative error
634  * pointer otherwise.
635  */
636 struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
637 						struct drm_encoder *encoder)
638 {
639 	struct drm_bridge_connector *bridge_connector;
640 	struct drm_connector *connector;
641 	struct i2c_adapter *ddc = NULL;
642 	struct drm_bridge *bridge, *panel_bridge = NULL;
643 	unsigned int supported_formats = BIT(HDMI_COLORSPACE_RGB);
644 	unsigned int max_bpc = 8;
645 	bool support_hdcp = false;
646 	int connector_type;
647 	int ret;
648 
649 	bridge_connector = drmm_kzalloc(drm, sizeof(*bridge_connector), GFP_KERNEL);
650 	if (!bridge_connector)
651 		return ERR_PTR(-ENOMEM);
652 
653 	bridge_connector->encoder = encoder;
654 
655 	/*
656 	 * TODO: Handle doublescan_allowed and stereo_allowed.
657 	 */
658 	connector = &bridge_connector->base;
659 	connector->interlace_allowed = true;
660 	connector->ycbcr_420_allowed = true;
661 
662 	/*
663 	 * Initialise connector status handling. First locate the furthest
664 	 * bridges in the pipeline that support HPD and output detection. Then
665 	 * initialise the connector polling mode, using HPD if available and
666 	 * falling back to polling if supported. If neither HPD nor output
667 	 * detection are available, we don't support hotplug detection at all.
668 	 */
669 	connector_type = DRM_MODE_CONNECTOR_Unknown;
670 	drm_for_each_bridge_in_chain(encoder, bridge) {
671 		if (!bridge->interlace_allowed)
672 			connector->interlace_allowed = false;
673 		if (!bridge->ycbcr_420_allowed)
674 			connector->ycbcr_420_allowed = false;
675 
676 		if (bridge->ops & DRM_BRIDGE_OP_EDID)
677 			bridge_connector->bridge_edid = bridge;
678 		if (bridge->ops & DRM_BRIDGE_OP_HPD)
679 			bridge_connector->bridge_hpd = bridge;
680 		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
681 			bridge_connector->bridge_detect = bridge;
682 		if (bridge->ops & DRM_BRIDGE_OP_MODES)
683 			bridge_connector->bridge_modes = bridge;
684 		if (bridge->ops & DRM_BRIDGE_OP_HDMI) {
685 			if (bridge_connector->bridge_hdmi)
686 				return ERR_PTR(-EBUSY);
687 			if (!bridge->funcs->hdmi_write_infoframe ||
688 			    !bridge->funcs->hdmi_clear_infoframe)
689 				return ERR_PTR(-EINVAL);
690 
691 			bridge_connector->bridge_hdmi = bridge;
692 
693 			if (bridge->supported_formats)
694 				supported_formats = bridge->supported_formats;
695 			if (bridge->max_bpc)
696 				max_bpc = bridge->max_bpc;
697 		}
698 
699 		if (bridge->ops & DRM_BRIDGE_OP_HDMI_AUDIO) {
700 			if (bridge_connector->bridge_hdmi_audio)
701 				return ERR_PTR(-EBUSY);
702 
703 			if (bridge_connector->bridge_dp_audio)
704 				return ERR_PTR(-EBUSY);
705 
706 			if (!bridge->hdmi_audio_max_i2s_playback_channels &&
707 			    !bridge->hdmi_audio_spdif_playback)
708 				return ERR_PTR(-EINVAL);
709 
710 			if (!bridge->funcs->hdmi_audio_prepare ||
711 			    !bridge->funcs->hdmi_audio_shutdown)
712 				return ERR_PTR(-EINVAL);
713 
714 			bridge_connector->bridge_hdmi_audio = bridge;
715 		}
716 
717 		if (bridge->ops & DRM_BRIDGE_OP_DP_AUDIO) {
718 			if (bridge_connector->bridge_dp_audio)
719 				return ERR_PTR(-EBUSY);
720 
721 			if (bridge_connector->bridge_hdmi_audio)
722 				return ERR_PTR(-EBUSY);
723 
724 			if (!bridge->hdmi_audio_max_i2s_playback_channels &&
725 			    !bridge->hdmi_audio_spdif_playback)
726 				return ERR_PTR(-EINVAL);
727 
728 			if (!bridge->funcs->dp_audio_prepare ||
729 			    !bridge->funcs->dp_audio_shutdown)
730 				return ERR_PTR(-EINVAL);
731 
732 			bridge_connector->bridge_dp_audio = bridge;
733 		}
734 
735 		if (bridge->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) {
736 			if (bridge_connector->bridge_hdmi_cec)
737 				return ERR_PTR(-EBUSY);
738 
739 			bridge_connector->bridge_hdmi_cec = bridge;
740 		}
741 
742 		if (bridge->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) {
743 			if (bridge_connector->bridge_hdmi_cec)
744 				return ERR_PTR(-EBUSY);
745 
746 			bridge_connector->bridge_hdmi_cec = bridge;
747 
748 			if (!bridge->funcs->hdmi_cec_enable ||
749 			    !bridge->funcs->hdmi_cec_log_addr ||
750 			    !bridge->funcs->hdmi_cec_transmit)
751 				return ERR_PTR(-EINVAL);
752 		}
753 
754 		if (drm_bridge_is_last(bridge))
755 			connector_type = bridge->type;
756 
757 #ifdef CONFIG_OF
758 		if (drm_bridge_is_last(bridge) && bridge->of_node)
759 			connector->fwnode = fwnode_handle_get(of_fwnode_handle(bridge->of_node));
760 #endif
761 
762 		if (bridge->ddc)
763 			ddc = bridge->ddc;
764 
765 		if (drm_bridge_is_panel(bridge))
766 			panel_bridge = bridge;
767 
768 		if (bridge->support_hdcp)
769 			support_hdcp = true;
770 	}
771 
772 	if (connector_type == DRM_MODE_CONNECTOR_Unknown)
773 		return ERR_PTR(-EINVAL);
774 
775 	if (bridge_connector->bridge_hdmi) {
776 		if (!connector->ycbcr_420_allowed)
777 			supported_formats &= ~BIT(HDMI_COLORSPACE_YUV420);
778 
779 		ret = drmm_connector_hdmi_init(drm, connector,
780 					       bridge_connector->bridge_hdmi->vendor,
781 					       bridge_connector->bridge_hdmi->product,
782 					       &drm_bridge_connector_funcs,
783 					       &drm_bridge_connector_hdmi_funcs,
784 					       connector_type, ddc,
785 					       supported_formats,
786 					       max_bpc);
787 		if (ret)
788 			return ERR_PTR(ret);
789 	} else {
790 		ret = drmm_connector_init(drm, connector,
791 					  &drm_bridge_connector_funcs,
792 					  connector_type, ddc);
793 		if (ret)
794 			return ERR_PTR(ret);
795 	}
796 
797 	if (bridge_connector->bridge_hdmi_audio ||
798 	    bridge_connector->bridge_dp_audio) {
799 		struct device *dev;
800 		struct drm_bridge *bridge;
801 
802 		if (bridge_connector->bridge_hdmi_audio)
803 			bridge = bridge_connector->bridge_hdmi_audio;
804 		else
805 			bridge = bridge_connector->bridge_dp_audio;
806 
807 		dev = bridge->hdmi_audio_dev;
808 
809 		ret = drm_connector_hdmi_audio_init(connector, dev,
810 						    &drm_bridge_connector_hdmi_audio_funcs,
811 						    bridge->hdmi_audio_max_i2s_playback_channels,
812 						    bridge->hdmi_audio_i2s_formats,
813 						    bridge->hdmi_audio_spdif_playback,
814 						    bridge->hdmi_audio_dai_port);
815 		if (ret)
816 			return ERR_PTR(ret);
817 	}
818 
819 	if (bridge_connector->bridge_hdmi_cec &&
820 	    bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_NOTIFIER) {
821 		bridge = bridge_connector->bridge_hdmi_cec;
822 
823 		ret = drmm_connector_hdmi_cec_notifier_register(connector,
824 								NULL,
825 								bridge->hdmi_cec_dev);
826 		if (ret)
827 			return ERR_PTR(ret);
828 	}
829 
830 	if (bridge_connector->bridge_hdmi_cec &&
831 	    bridge_connector->bridge_hdmi_cec->ops & DRM_BRIDGE_OP_HDMI_CEC_ADAPTER) {
832 		bridge = bridge_connector->bridge_hdmi_cec;
833 
834 		ret = drmm_connector_hdmi_cec_register(connector,
835 						       &drm_bridge_connector_hdmi_cec_funcs,
836 						       bridge->hdmi_cec_adapter_name,
837 						       bridge->hdmi_cec_available_las,
838 						       bridge->hdmi_cec_dev);
839 		if (ret)
840 			return ERR_PTR(ret);
841 	}
842 
843 	drm_connector_helper_add(connector, &drm_bridge_connector_helper_funcs);
844 
845 	if (bridge_connector->bridge_hpd)
846 		connector->polled = DRM_CONNECTOR_POLL_HPD;
847 	else if (bridge_connector->bridge_detect)
848 		connector->polled = DRM_CONNECTOR_POLL_CONNECT
849 				  | DRM_CONNECTOR_POLL_DISCONNECT;
850 
851 	if (panel_bridge)
852 		drm_panel_bridge_set_orientation(connector, panel_bridge);
853 
854 	if (support_hdcp && IS_REACHABLE(CONFIG_DRM_DISPLAY_HELPER) &&
855 	    IS_ENABLED(CONFIG_DRM_DISPLAY_HDCP_HELPER))
856 		drm_connector_attach_content_protection_property(connector, true);
857 
858 	return connector;
859 }
860 EXPORT_SYMBOL_GPL(drm_bridge_connector_init);
861