Line data Source code
1 : /*
2 : * Copyright (c) 2014 Samsung Electronics Co., Ltd
3 : *
4 : * Permission is hereby granted, free of charge, to any person obtaining a
5 : * copy of this software and associated documentation files (the "Software"),
6 : * to deal in the Software without restriction, including without limitation
7 : * the rights to use, copy, modify, merge, publish, distribute, sub license,
8 : * and/or sell copies of the Software, and to permit persons to whom the
9 : * Software is furnished to do so, subject to the following conditions:
10 : *
11 : * The above copyright notice and this permission notice (including the
12 : * next paragraph) shall be included in all copies or substantial portions
13 : * of the Software.
14 : *
15 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 : * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 : * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 : * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 : * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 : * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 : * DEALINGS IN THE SOFTWARE.
22 : */
23 :
24 : #include <linux/err.h>
25 : #include <linux/media-bus-format.h>
26 : #include <linux/module.h>
27 : #include <linux/mutex.h>
28 :
29 : #include <drm/drm_atomic_state_helper.h>
30 : #include <drm/drm_debugfs.h>
31 : #include <drm/drm_bridge.h>
32 : #include <drm/drm_encoder.h>
33 : #include <drm/drm_file.h>
34 : #include <drm/drm_of.h>
35 : #include <drm/drm_print.h>
36 :
37 : #include "drm_crtc_internal.h"
38 :
39 : /**
40 : * DOC: overview
41 : *
42 : * &struct drm_bridge represents a device that hangs on to an encoder. These are
43 : * handy when a regular &drm_encoder entity isn't enough to represent the entire
44 : * encoder chain.
45 : *
46 : * A bridge is always attached to a single &drm_encoder at a time, but can be
47 : * either connected to it directly, or through a chain of bridges::
48 : *
49 : * [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
50 : *
51 : * Here, the output of the encoder feeds to bridge A, and that furthers feeds to
52 : * bridge B. Bridge chains can be arbitrarily long, and shall be fully linear:
53 : * Chaining multiple bridges to the output of a bridge, or the same bridge to
54 : * the output of different bridges, is not supported.
55 : *
56 : * &drm_bridge, like &drm_panel, aren't &drm_mode_object entities like planes,
57 : * CRTCs, encoders or connectors and hence are not visible to userspace. They
58 : * just provide additional hooks to get the desired output at the end of the
59 : * encoder chain.
60 : */
61 :
62 : /**
63 : * DOC: display driver integration
64 : *
65 : * Display drivers are responsible for linking encoders with the first bridge
66 : * in the chains. This is done by acquiring the appropriate bridge with
67 : * devm_drm_of_get_bridge(). Once acquired, the bridge shall be attached to the
68 : * encoder with a call to drm_bridge_attach().
69 : *
70 : * Bridges are responsible for linking themselves with the next bridge in the
71 : * chain, if any. This is done the same way as for encoders, with the call to
72 : * drm_bridge_attach() occurring in the &drm_bridge_funcs.attach operation.
73 : *
74 : * Once these links are created, the bridges can participate along with encoder
75 : * functions to perform mode validation and fixup (through
76 : * drm_bridge_chain_mode_valid() and drm_atomic_bridge_chain_check()), mode
77 : * setting (through drm_bridge_chain_mode_set()), enable (through
78 : * drm_atomic_bridge_chain_pre_enable() and drm_atomic_bridge_chain_enable())
79 : * and disable (through drm_atomic_bridge_chain_disable() and
80 : * drm_atomic_bridge_chain_post_disable()). Those functions call the
81 : * corresponding operations provided in &drm_bridge_funcs in sequence for all
82 : * bridges in the chain.
83 : *
84 : * For display drivers that use the atomic helpers
85 : * drm_atomic_helper_check_modeset(),
86 : * drm_atomic_helper_commit_modeset_enables() and
87 : * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
88 : * commit check and commit tail handlers, or through the higher-level
89 : * drm_atomic_helper_check() and drm_atomic_helper_commit_tail() or
90 : * drm_atomic_helper_commit_tail_rpm() helpers), this is done transparently and
91 : * requires no intervention from the driver. For other drivers, the relevant
92 : * DRM bridge chain functions shall be called manually.
93 : *
94 : * Bridges also participate in implementing the &drm_connector at the end of
95 : * the bridge chain. Display drivers may use the drm_bridge_connector_init()
96 : * helper to create the &drm_connector, or implement it manually on top of the
97 : * connector-related operations exposed by the bridge (see the overview
98 : * documentation of bridge operations for more details).
99 : */
100 :
101 : /**
102 : * DOC: special care dsi
103 : *
104 : * The interaction between the bridges and other frameworks involved in
105 : * the probing of the upstream driver and the bridge driver can be
106 : * challenging. Indeed, there's multiple cases that needs to be
107 : * considered:
108 : *
109 : * - The upstream driver doesn't use the component framework and isn't a
110 : * MIPI-DSI host. In this case, the bridge driver will probe at some
111 : * point and the upstream driver should try to probe again by returning
112 : * EPROBE_DEFER as long as the bridge driver hasn't probed.
113 : *
114 : * - The upstream driver doesn't use the component framework, but is a
115 : * MIPI-DSI host. The bridge device uses the MIPI-DCS commands to be
116 : * controlled. In this case, the bridge device is a child of the
117 : * display device and when it will probe it's assured that the display
118 : * device (and MIPI-DSI host) is present. The upstream driver will be
119 : * assured that the bridge driver is connected between the
120 : * &mipi_dsi_host_ops.attach and &mipi_dsi_host_ops.detach operations.
121 : * Therefore, it must run mipi_dsi_host_register() in its probe
122 : * function, and then run drm_bridge_attach() in its
123 : * &mipi_dsi_host_ops.attach hook.
124 : *
125 : * - The upstream driver uses the component framework and is a MIPI-DSI
126 : * host. The bridge device uses the MIPI-DCS commands to be
127 : * controlled. This is the same situation than above, and can run
128 : * mipi_dsi_host_register() in either its probe or bind hooks.
129 : *
130 : * - The upstream driver uses the component framework and is a MIPI-DSI
131 : * host. The bridge device uses a separate bus (such as I2C) to be
132 : * controlled. In this case, there's no correlation between the probe
133 : * of the bridge and upstream drivers, so care must be taken to avoid
134 : * an endless EPROBE_DEFER loop, with each driver waiting for the
135 : * other to probe.
136 : *
137 : * The ideal pattern to cover the last item (and all the others in the
138 : * MIPI-DSI host driver case) is to split the operations like this:
139 : *
140 : * - The MIPI-DSI host driver must run mipi_dsi_host_register() in its
141 : * probe hook. It will make sure that the MIPI-DSI host sticks around,
142 : * and that the driver's bind can be called.
143 : *
144 : * - In its probe hook, the bridge driver must try to find its MIPI-DSI
145 : * host, register as a MIPI-DSI device and attach the MIPI-DSI device
146 : * to its host. The bridge driver is now functional.
147 : *
148 : * - In its &struct mipi_dsi_host_ops.attach hook, the MIPI-DSI host can
149 : * now add its component. Its bind hook will now be called and since
150 : * the bridge driver is attached and registered, we can now look for
151 : * and attach it.
152 : *
153 : * At this point, we're now certain that both the upstream driver and
154 : * the bridge driver are functional and we can't have a deadlock-like
155 : * situation when probing.
156 : */
157 :
158 : /**
159 : * DOC: dsi bridge operations
160 : *
161 : * DSI host interfaces are expected to be implemented as bridges rather than
162 : * encoders, however there are a few aspects of their operation that need to
163 : * be defined in order to provide a consistent interface.
164 : *
165 : * A DSI host should keep the PHY powered down until the pre_enable operation is
166 : * called. All lanes are in an undefined idle state up to this point, and it
167 : * must not be assumed that it is LP-11.
168 : * pre_enable should initialise the PHY, set the data lanes to LP-11, and the
169 : * clock lane to either LP-11 or HS depending on the mode_flag
170 : * %MIPI_DSI_CLOCK_NON_CONTINUOUS.
171 : *
172 : * Ordinarily the downstream bridge DSI peripheral pre_enable will have been
173 : * called before the DSI host. If the DSI peripheral requires LP-11 and/or
174 : * the clock lane to be in HS mode prior to pre_enable, then it can set the
175 : * &pre_enable_prev_first flag to request the pre_enable (and
176 : * post_disable) order to be altered to enable the DSI host first.
177 : *
178 : * Either the CRTC being enabled, or the DSI host enable operation should switch
179 : * the host to actively transmitting video on the data lanes.
180 : *
181 : * The reverse also applies. The DSI host disable operation or stopping the CRTC
182 : * should stop transmitting video, and the data lanes should return to the LP-11
183 : * state. The DSI host &post_disable operation should disable the PHY.
184 : * If the &pre_enable_prev_first flag is set, then the DSI peripheral's
185 : * bridge &post_disable will be called before the DSI host's post_disable.
186 : *
187 : * Whilst it is valid to call &host_transfer prior to pre_enable or after
188 : * post_disable, the exact state of the lanes is undefined at this point. The
189 : * DSI host should initialise the interface, transmit the data, and then disable
190 : * the interface again.
191 : *
192 : * Ultra Low Power State (ULPS) is not explicitly supported by DRM. If
193 : * implemented, it therefore needs to be handled entirely within the DSI Host
194 : * driver.
195 : */
196 :
197 : static DEFINE_MUTEX(bridge_lock);
198 : static LIST_HEAD(bridge_list);
199 :
200 : /**
201 : * drm_bridge_add - add the given bridge to the global bridge list
202 : *
203 : * @bridge: bridge control structure
204 : */
205 0 : void drm_bridge_add(struct drm_bridge *bridge)
206 : {
207 0 : mutex_init(&bridge->hpd_mutex);
208 :
209 0 : mutex_lock(&bridge_lock);
210 0 : list_add_tail(&bridge->list, &bridge_list);
211 0 : mutex_unlock(&bridge_lock);
212 0 : }
213 : EXPORT_SYMBOL(drm_bridge_add);
214 :
215 0 : static void drm_bridge_remove_void(void *bridge)
216 : {
217 0 : drm_bridge_remove(bridge);
218 0 : }
219 :
220 : /**
221 : * devm_drm_bridge_add - devm managed version of drm_bridge_add()
222 : *
223 : * @dev: device to tie the bridge lifetime to
224 : * @bridge: bridge control structure
225 : *
226 : * This is the managed version of drm_bridge_add() which automatically
227 : * calls drm_bridge_remove() when @dev is unbound.
228 : *
229 : * Return: 0 if no error or negative error code.
230 : */
231 0 : int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge)
232 : {
233 0 : drm_bridge_add(bridge);
234 0 : return devm_add_action_or_reset(dev, drm_bridge_remove_void, bridge);
235 : }
236 : EXPORT_SYMBOL(devm_drm_bridge_add);
237 :
238 : /**
239 : * drm_bridge_remove - remove the given bridge from the global bridge list
240 : *
241 : * @bridge: bridge control structure
242 : */
243 0 : void drm_bridge_remove(struct drm_bridge *bridge)
244 : {
245 0 : mutex_lock(&bridge_lock);
246 0 : list_del_init(&bridge->list);
247 0 : mutex_unlock(&bridge_lock);
248 :
249 0 : mutex_destroy(&bridge->hpd_mutex);
250 0 : }
251 : EXPORT_SYMBOL(drm_bridge_remove);
252 :
253 : static struct drm_private_state *
254 0 : drm_bridge_atomic_duplicate_priv_state(struct drm_private_obj *obj)
255 : {
256 0 : struct drm_bridge *bridge = drm_priv_to_bridge(obj);
257 : struct drm_bridge_state *state;
258 :
259 0 : state = bridge->funcs->atomic_duplicate_state(bridge);
260 0 : return state ? &state->base : NULL;
261 : }
262 :
263 : static void
264 0 : drm_bridge_atomic_destroy_priv_state(struct drm_private_obj *obj,
265 : struct drm_private_state *s)
266 : {
267 0 : struct drm_bridge_state *state = drm_priv_to_bridge_state(s);
268 0 : struct drm_bridge *bridge = drm_priv_to_bridge(obj);
269 :
270 0 : bridge->funcs->atomic_destroy_state(bridge, state);
271 0 : }
272 :
273 : static const struct drm_private_state_funcs drm_bridge_priv_state_funcs = {
274 : .atomic_duplicate_state = drm_bridge_atomic_duplicate_priv_state,
275 : .atomic_destroy_state = drm_bridge_atomic_destroy_priv_state,
276 : };
277 :
278 : /**
279 : * drm_bridge_attach - attach the bridge to an encoder's chain
280 : *
281 : * @encoder: DRM encoder
282 : * @bridge: bridge to attach
283 : * @previous: previous bridge in the chain (optional)
284 : * @flags: DRM_BRIDGE_ATTACH_* flags
285 : *
286 : * Called by a kms driver to link the bridge to an encoder's chain. The previous
287 : * argument specifies the previous bridge in the chain. If NULL, the bridge is
288 : * linked directly at the encoder's output. Otherwise it is linked at the
289 : * previous bridge's output.
290 : *
291 : * If non-NULL the previous bridge must be already attached by a call to this
292 : * function.
293 : *
294 : * Note that bridges attached to encoders are auto-detached during encoder
295 : * cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally
296 : * *not* be balanced with a drm_bridge_detach() in driver code.
297 : *
298 : * RETURNS:
299 : * Zero on success, error code on failure
300 : */
301 0 : int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
302 : struct drm_bridge *previous,
303 : enum drm_bridge_attach_flags flags)
304 : {
305 : int ret;
306 :
307 0 : if (!encoder || !bridge)
308 : return -EINVAL;
309 :
310 0 : if (previous && (!previous->dev || previous->encoder != encoder))
311 : return -EINVAL;
312 :
313 0 : if (bridge->dev)
314 : return -EBUSY;
315 :
316 0 : bridge->dev = encoder->dev;
317 0 : bridge->encoder = encoder;
318 :
319 0 : if (previous)
320 0 : list_add(&bridge->chain_node, &previous->chain_node);
321 : else
322 0 : list_add(&bridge->chain_node, &encoder->bridge_chain);
323 :
324 0 : if (bridge->funcs->attach) {
325 0 : ret = bridge->funcs->attach(bridge, flags);
326 0 : if (ret < 0)
327 : goto err_reset_bridge;
328 : }
329 :
330 0 : if (bridge->funcs->atomic_reset) {
331 : struct drm_bridge_state *state;
332 :
333 0 : state = bridge->funcs->atomic_reset(bridge);
334 0 : if (IS_ERR(state)) {
335 0 : ret = PTR_ERR(state);
336 : goto err_detach_bridge;
337 : }
338 :
339 0 : drm_atomic_private_obj_init(bridge->dev, &bridge->base,
340 : &state->base,
341 : &drm_bridge_priv_state_funcs);
342 : }
343 :
344 : return 0;
345 :
346 : err_detach_bridge:
347 0 : if (bridge->funcs->detach)
348 0 : bridge->funcs->detach(bridge);
349 :
350 : err_reset_bridge:
351 0 : bridge->dev = NULL;
352 0 : bridge->encoder = NULL;
353 0 : list_del(&bridge->chain_node);
354 :
355 : #ifdef CONFIG_OF
356 : DRM_ERROR("failed to attach bridge %pOF to encoder %s: %d\n",
357 : bridge->of_node, encoder->name, ret);
358 : #else
359 0 : DRM_ERROR("failed to attach bridge to encoder %s: %d\n",
360 : encoder->name, ret);
361 : #endif
362 :
363 0 : return ret;
364 : }
365 : EXPORT_SYMBOL(drm_bridge_attach);
366 :
367 0 : void drm_bridge_detach(struct drm_bridge *bridge)
368 : {
369 0 : if (WARN_ON(!bridge))
370 : return;
371 :
372 0 : if (WARN_ON(!bridge->dev))
373 : return;
374 :
375 0 : if (bridge->funcs->atomic_reset)
376 0 : drm_atomic_private_obj_fini(&bridge->base);
377 :
378 0 : if (bridge->funcs->detach)
379 0 : bridge->funcs->detach(bridge);
380 :
381 0 : list_del(&bridge->chain_node);
382 0 : bridge->dev = NULL;
383 : }
384 :
385 : /**
386 : * DOC: bridge operations
387 : *
388 : * Bridge drivers expose operations through the &drm_bridge_funcs structure.
389 : * The DRM internals (atomic and CRTC helpers) use the helpers defined in
390 : * drm_bridge.c to call bridge operations. Those operations are divided in
391 : * three big categories to support different parts of the bridge usage.
392 : *
393 : * - The encoder-related operations support control of the bridges in the
394 : * chain, and are roughly counterparts to the &drm_encoder_helper_funcs
395 : * operations. They are used by the legacy CRTC and the atomic modeset
396 : * helpers to perform mode validation, fixup and setting, and enable and
397 : * disable the bridge automatically.
398 : *
399 : * The enable and disable operations are split in
400 : * &drm_bridge_funcs.pre_enable, &drm_bridge_funcs.enable,
401 : * &drm_bridge_funcs.disable and &drm_bridge_funcs.post_disable to provide
402 : * finer-grained control.
403 : *
404 : * Bridge drivers may implement the legacy version of those operations, or
405 : * the atomic version (prefixed with atomic\_), in which case they shall also
406 : * implement the atomic state bookkeeping operations
407 : * (&drm_bridge_funcs.atomic_duplicate_state,
408 : * &drm_bridge_funcs.atomic_destroy_state and &drm_bridge_funcs.reset).
409 : * Mixing atomic and non-atomic versions of the operations is not supported.
410 : *
411 : * - The bus format negotiation operations
412 : * &drm_bridge_funcs.atomic_get_output_bus_fmts and
413 : * &drm_bridge_funcs.atomic_get_input_bus_fmts allow bridge drivers to
414 : * negotiate the formats transmitted between bridges in the chain when
415 : * multiple formats are supported. Negotiation for formats is performed
416 : * transparently for display drivers by the atomic modeset helpers. Only
417 : * atomic versions of those operations exist, bridge drivers that need to
418 : * implement them shall thus also implement the atomic version of the
419 : * encoder-related operations. This feature is not supported by the legacy
420 : * CRTC helpers.
421 : *
422 : * - The connector-related operations support implementing a &drm_connector
423 : * based on a chain of bridges. DRM bridges traditionally create a
424 : * &drm_connector for bridges meant to be used at the end of the chain. This
425 : * puts additional burden on bridge drivers, especially for bridges that may
426 : * be used in the middle of a chain or at the end of it. Furthermore, it
427 : * requires all operations of the &drm_connector to be handled by a single
428 : * bridge, which doesn't always match the hardware architecture.
429 : *
430 : * To simplify bridge drivers and make the connector implementation more
431 : * flexible, a new model allows bridges to unconditionally skip creation of
432 : * &drm_connector and instead expose &drm_bridge_funcs operations to support
433 : * an externally-implemented &drm_connector. Those operations are
434 : * &drm_bridge_funcs.detect, &drm_bridge_funcs.get_modes,
435 : * &drm_bridge_funcs.get_edid, &drm_bridge_funcs.hpd_notify,
436 : * &drm_bridge_funcs.hpd_enable and &drm_bridge_funcs.hpd_disable. When
437 : * implemented, display drivers shall create a &drm_connector instance for
438 : * each chain of bridges, and implement those connector instances based on
439 : * the bridge connector operations.
440 : *
441 : * Bridge drivers shall implement the connector-related operations for all
442 : * the features that the bridge hardware support. For instance, if a bridge
443 : * supports reading EDID, the &drm_bridge_funcs.get_edid shall be
444 : * implemented. This however doesn't mean that the DDC lines are wired to the
445 : * bridge on a particular platform, as they could also be connected to an I2C
446 : * controller of the SoC. Support for the connector-related operations on the
447 : * running platform is reported through the &drm_bridge.ops flags. Bridge
448 : * drivers shall detect which operations they can support on the platform
449 : * (usually this information is provided by ACPI or DT), and set the
450 : * &drm_bridge.ops flags for all supported operations. A flag shall only be
451 : * set if the corresponding &drm_bridge_funcs operation is implemented, but
452 : * an implemented operation doesn't necessarily imply that the corresponding
453 : * flag will be set. Display drivers shall use the &drm_bridge.ops flags to
454 : * decide which bridge to delegate a connector operation to. This mechanism
455 : * allows providing a single static const &drm_bridge_funcs instance in
456 : * bridge drivers, improving security by storing function pointers in
457 : * read-only memory.
458 : *
459 : * In order to ease transition, bridge drivers may support both the old and
460 : * new models by making connector creation optional and implementing the
461 : * connected-related bridge operations. Connector creation is then controlled
462 : * by the flags argument to the drm_bridge_attach() function. Display drivers
463 : * that support the new model and create connectors themselves shall set the
464 : * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, and bridge drivers shall then skip
465 : * connector creation. For intermediate bridges in the chain, the flag shall
466 : * be passed to the drm_bridge_attach() call for the downstream bridge.
467 : * Bridge drivers that implement the new model only shall return an error
468 : * from their &drm_bridge_funcs.attach handler when the
469 : * %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
470 : * should use the new model, and convert the bridge drivers they use if
471 : * needed, in order to gradually transition to the new model.
472 : */
473 :
474 : /**
475 : * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the
476 : * encoder chain
477 : * @bridge: bridge control structure
478 : * @mode: desired mode to be set for the bridge
479 : * @adjusted_mode: updated mode that works for this bridge
480 : *
481 : * Calls &drm_bridge_funcs.mode_fixup for all the bridges in the
482 : * encoder chain, starting from the first bridge to the last.
483 : *
484 : * Note: the bridge passed should be the one closest to the encoder
485 : *
486 : * RETURNS:
487 : * true on success, false on failure
488 : */
489 0 : bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
490 : const struct drm_display_mode *mode,
491 : struct drm_display_mode *adjusted_mode)
492 : {
493 : struct drm_encoder *encoder;
494 :
495 0 : if (!bridge)
496 : return true;
497 :
498 0 : encoder = bridge->encoder;
499 0 : list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
500 0 : if (!bridge->funcs->mode_fixup)
501 0 : continue;
502 :
503 0 : if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))
504 : return false;
505 : }
506 :
507 : return true;
508 : }
509 : EXPORT_SYMBOL(drm_bridge_chain_mode_fixup);
510 :
511 : /**
512 : * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
513 : * encoder chain.
514 : * @bridge: bridge control structure
515 : * @info: display info against which the mode shall be validated
516 : * @mode: desired mode to be validated
517 : *
518 : * Calls &drm_bridge_funcs.mode_valid for all the bridges in the encoder
519 : * chain, starting from the first bridge to the last. If at least one bridge
520 : * does not accept the mode the function returns the error code.
521 : *
522 : * Note: the bridge passed should be the one closest to the encoder.
523 : *
524 : * RETURNS:
525 : * MODE_OK on success, drm_mode_status Enum error code on failure
526 : */
527 : enum drm_mode_status
528 0 : drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
529 : const struct drm_display_info *info,
530 : const struct drm_display_mode *mode)
531 : {
532 : struct drm_encoder *encoder;
533 :
534 0 : if (!bridge)
535 : return MODE_OK;
536 :
537 0 : encoder = bridge->encoder;
538 0 : list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
539 : enum drm_mode_status ret;
540 :
541 0 : if (!bridge->funcs->mode_valid)
542 0 : continue;
543 :
544 0 : ret = bridge->funcs->mode_valid(bridge, info, mode);
545 0 : if (ret != MODE_OK)
546 : return ret;
547 : }
548 :
549 : return MODE_OK;
550 : }
551 : EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
552 :
553 : /**
554 : * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
555 : * encoder chain
556 : * @bridge: bridge control structure
557 : * @mode: desired mode to be set for the encoder chain
558 : * @adjusted_mode: updated mode that works for this encoder chain
559 : *
560 : * Calls &drm_bridge_funcs.mode_set op for all the bridges in the
561 : * encoder chain, starting from the first bridge to the last.
562 : *
563 : * Note: the bridge passed should be the one closest to the encoder
564 : */
565 0 : void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
566 : const struct drm_display_mode *mode,
567 : const struct drm_display_mode *adjusted_mode)
568 : {
569 : struct drm_encoder *encoder;
570 :
571 0 : if (!bridge)
572 : return;
573 :
574 0 : encoder = bridge->encoder;
575 0 : list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
576 0 : if (bridge->funcs->mode_set)
577 0 : bridge->funcs->mode_set(bridge, mode, adjusted_mode);
578 : }
579 : }
580 : EXPORT_SYMBOL(drm_bridge_chain_mode_set);
581 :
582 : /**
583 : * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
584 : * @bridge: bridge control structure
585 : * @old_state: old atomic state
586 : *
587 : * Calls &drm_bridge_funcs.atomic_disable (falls back on
588 : * &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
589 : * starting from the last bridge to the first. These are called before calling
590 : * &drm_encoder_helper_funcs.atomic_disable
591 : *
592 : * Note: the bridge passed should be the one closest to the encoder
593 : */
594 0 : void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
595 : struct drm_atomic_state *old_state)
596 : {
597 : struct drm_encoder *encoder;
598 : struct drm_bridge *iter;
599 :
600 0 : if (!bridge)
601 : return;
602 :
603 0 : encoder = bridge->encoder;
604 0 : list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
605 0 : if (iter->funcs->atomic_disable) {
606 : struct drm_bridge_state *old_bridge_state;
607 :
608 0 : old_bridge_state =
609 : drm_atomic_get_old_bridge_state(old_state,
610 : iter);
611 0 : if (WARN_ON(!old_bridge_state))
612 : return;
613 :
614 0 : iter->funcs->atomic_disable(iter, old_bridge_state);
615 0 : } else if (iter->funcs->disable) {
616 0 : iter->funcs->disable(iter);
617 : }
618 :
619 0 : if (iter == bridge)
620 : break;
621 : }
622 : }
623 : EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
624 :
625 0 : static void drm_atomic_bridge_call_post_disable(struct drm_bridge *bridge,
626 : struct drm_atomic_state *old_state)
627 : {
628 0 : if (old_state && bridge->funcs->atomic_post_disable) {
629 : struct drm_bridge_state *old_bridge_state;
630 :
631 0 : old_bridge_state =
632 : drm_atomic_get_old_bridge_state(old_state,
633 : bridge);
634 0 : if (WARN_ON(!old_bridge_state))
635 : return;
636 :
637 0 : bridge->funcs->atomic_post_disable(bridge,
638 : old_bridge_state);
639 0 : } else if (bridge->funcs->post_disable) {
640 0 : bridge->funcs->post_disable(bridge);
641 : }
642 : }
643 :
644 : /**
645 : * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
646 : * in the encoder chain
647 : * @bridge: bridge control structure
648 : * @old_state: old atomic state
649 : *
650 : * Calls &drm_bridge_funcs.atomic_post_disable (falls back on
651 : * &drm_bridge_funcs.post_disable) op for all the bridges in the encoder chain,
652 : * starting from the first bridge to the last. These are called after completing
653 : * &drm_encoder_helper_funcs.atomic_disable
654 : *
655 : * If a bridge sets @pre_enable_prev_first, then the @post_disable for that
656 : * bridge will be called before the previous one to reverse the @pre_enable
657 : * calling direction.
658 : *
659 : * Note: the bridge passed should be the one closest to the encoder
660 : */
661 0 : void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
662 : struct drm_atomic_state *old_state)
663 : {
664 : struct drm_encoder *encoder;
665 : struct drm_bridge *next, *limit;
666 :
667 0 : if (!bridge)
668 : return;
669 :
670 0 : encoder = bridge->encoder;
671 :
672 0 : list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
673 0 : limit = NULL;
674 :
675 0 : if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) {
676 0 : next = list_next_entry(bridge, chain_node);
677 :
678 0 : if (next->pre_enable_prev_first) {
679 : /* next bridge had requested that prev
680 : * was enabled first, so disabled last
681 : */
682 : limit = next;
683 :
684 : /* Find the next bridge that has NOT requested
685 : * prev to be enabled first / disabled last
686 : */
687 0 : list_for_each_entry_from(next, &encoder->bridge_chain,
688 : chain_node) {
689 0 : if (next->pre_enable_prev_first) {
690 0 : next = list_prev_entry(next, chain_node);
691 0 : limit = next;
692 0 : break;
693 : }
694 : }
695 :
696 : /* Call these bridges in reverse order */
697 0 : list_for_each_entry_from_reverse(next, &encoder->bridge_chain,
698 : chain_node) {
699 0 : if (next == bridge)
700 : break;
701 :
702 0 : drm_atomic_bridge_call_post_disable(next,
703 : old_state);
704 : }
705 : }
706 : }
707 :
708 0 : drm_atomic_bridge_call_post_disable(bridge, old_state);
709 :
710 0 : if (limit)
711 : /* Jump all bridges that we have already post_disabled */
712 0 : bridge = limit;
713 : }
714 : }
715 : EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
716 :
717 0 : static void drm_atomic_bridge_call_pre_enable(struct drm_bridge *bridge,
718 : struct drm_atomic_state *old_state)
719 : {
720 0 : if (old_state && bridge->funcs->atomic_pre_enable) {
721 : struct drm_bridge_state *old_bridge_state;
722 :
723 0 : old_bridge_state =
724 : drm_atomic_get_old_bridge_state(old_state,
725 : bridge);
726 0 : if (WARN_ON(!old_bridge_state))
727 : return;
728 :
729 0 : bridge->funcs->atomic_pre_enable(bridge, old_bridge_state);
730 0 : } else if (bridge->funcs->pre_enable) {
731 0 : bridge->funcs->pre_enable(bridge);
732 : }
733 : }
734 :
735 : /**
736 : * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
737 : * the encoder chain
738 : * @bridge: bridge control structure
739 : * @old_state: old atomic state
740 : *
741 : * Calls &drm_bridge_funcs.atomic_pre_enable (falls back on
742 : * &drm_bridge_funcs.pre_enable) op for all the bridges in the encoder chain,
743 : * starting from the last bridge to the first. These are called before calling
744 : * &drm_encoder_helper_funcs.atomic_enable
745 : *
746 : * If a bridge sets @pre_enable_prev_first, then the pre_enable for the
747 : * prev bridge will be called before pre_enable of this bridge.
748 : *
749 : * Note: the bridge passed should be the one closest to the encoder
750 : */
751 0 : void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
752 : struct drm_atomic_state *old_state)
753 : {
754 : struct drm_encoder *encoder;
755 : struct drm_bridge *iter, *next, *limit;
756 :
757 0 : if (!bridge)
758 : return;
759 :
760 0 : encoder = bridge->encoder;
761 :
762 0 : list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
763 0 : if (iter->pre_enable_prev_first) {
764 : next = iter;
765 : limit = bridge;
766 0 : list_for_each_entry_from_reverse(next,
767 : &encoder->bridge_chain,
768 : chain_node) {
769 0 : if (next == bridge)
770 : break;
771 :
772 0 : if (!next->pre_enable_prev_first) {
773 : /* Found first bridge that does NOT
774 : * request prev to be enabled first
775 : */
776 0 : limit = list_prev_entry(next, chain_node);
777 0 : break;
778 : }
779 : }
780 :
781 0 : list_for_each_entry_from(next, &encoder->bridge_chain, chain_node) {
782 : /* Call requested prev bridge pre_enable
783 : * in order.
784 : */
785 0 : if (next == iter)
786 : /* At the first bridge to request prev
787 : * bridges called first.
788 : */
789 : break;
790 :
791 0 : drm_atomic_bridge_call_pre_enable(next, old_state);
792 : }
793 : }
794 :
795 0 : drm_atomic_bridge_call_pre_enable(iter, old_state);
796 :
797 0 : if (iter->pre_enable_prev_first)
798 : /* Jump all bridges that we have already pre_enabled */
799 0 : iter = limit;
800 :
801 0 : if (iter == bridge)
802 : break;
803 : }
804 : }
805 : EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
806 :
807 : /**
808 : * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
809 : * @bridge: bridge control structure
810 : * @old_state: old atomic state
811 : *
812 : * Calls &drm_bridge_funcs.atomic_enable (falls back on
813 : * &drm_bridge_funcs.enable) op for all the bridges in the encoder chain,
814 : * starting from the first bridge to the last. These are called after completing
815 : * &drm_encoder_helper_funcs.atomic_enable
816 : *
817 : * Note: the bridge passed should be the one closest to the encoder
818 : */
819 0 : void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
820 : struct drm_atomic_state *old_state)
821 : {
822 : struct drm_encoder *encoder;
823 :
824 0 : if (!bridge)
825 : return;
826 :
827 0 : encoder = bridge->encoder;
828 0 : list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {
829 0 : if (bridge->funcs->atomic_enable) {
830 : struct drm_bridge_state *old_bridge_state;
831 :
832 0 : old_bridge_state =
833 : drm_atomic_get_old_bridge_state(old_state,
834 : bridge);
835 0 : if (WARN_ON(!old_bridge_state))
836 : return;
837 :
838 0 : bridge->funcs->atomic_enable(bridge, old_bridge_state);
839 0 : } else if (bridge->funcs->enable) {
840 0 : bridge->funcs->enable(bridge);
841 : }
842 : }
843 : }
844 : EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);
845 :
846 0 : static int drm_atomic_bridge_check(struct drm_bridge *bridge,
847 : struct drm_crtc_state *crtc_state,
848 : struct drm_connector_state *conn_state)
849 : {
850 0 : if (bridge->funcs->atomic_check) {
851 : struct drm_bridge_state *bridge_state;
852 : int ret;
853 :
854 0 : bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
855 : bridge);
856 0 : if (WARN_ON(!bridge_state))
857 : return -EINVAL;
858 :
859 0 : ret = bridge->funcs->atomic_check(bridge, bridge_state,
860 : crtc_state, conn_state);
861 0 : if (ret)
862 : return ret;
863 0 : } else if (bridge->funcs->mode_fixup) {
864 0 : if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,
865 : &crtc_state->adjusted_mode))
866 : return -EINVAL;
867 : }
868 :
869 : return 0;
870 : }
871 :
872 0 : static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
873 : struct drm_bridge *cur_bridge,
874 : struct drm_crtc_state *crtc_state,
875 : struct drm_connector_state *conn_state,
876 : u32 out_bus_fmt)
877 : {
878 0 : unsigned int i, num_in_bus_fmts = 0;
879 : struct drm_bridge_state *cur_state;
880 : struct drm_bridge *prev_bridge;
881 : u32 *in_bus_fmts;
882 : int ret;
883 :
884 0 : prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
885 0 : cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
886 : cur_bridge);
887 :
888 : /*
889 : * If bus format negotiation is not supported by this bridge, let's
890 : * pass MEDIA_BUS_FMT_FIXED to the previous bridge in the chain and
891 : * hope that it can handle this situation gracefully (by providing
892 : * appropriate default values).
893 : */
894 0 : if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {
895 0 : if (cur_bridge != first_bridge) {
896 0 : ret = select_bus_fmt_recursive(first_bridge,
897 : prev_bridge, crtc_state,
898 : conn_state,
899 : MEDIA_BUS_FMT_FIXED);
900 0 : if (ret)
901 : return ret;
902 : }
903 :
904 : /*
905 : * Driver does not implement the atomic state hooks, but that's
906 : * fine, as long as it does not access the bridge state.
907 : */
908 0 : if (cur_state) {
909 0 : cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;
910 0 : cur_state->output_bus_cfg.format = out_bus_fmt;
911 : }
912 :
913 : return 0;
914 : }
915 :
916 : /*
917 : * If the driver implements ->atomic_get_input_bus_fmts() it
918 : * should also implement the atomic state hooks.
919 : */
920 0 : if (WARN_ON(!cur_state))
921 : return -EINVAL;
922 :
923 0 : in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,
924 : cur_state,
925 : crtc_state,
926 : conn_state,
927 : out_bus_fmt,
928 : &num_in_bus_fmts);
929 0 : if (!num_in_bus_fmts)
930 : return -ENOTSUPP;
931 0 : else if (!in_bus_fmts)
932 : return -ENOMEM;
933 :
934 0 : if (first_bridge == cur_bridge) {
935 0 : cur_state->input_bus_cfg.format = in_bus_fmts[0];
936 0 : cur_state->output_bus_cfg.format = out_bus_fmt;
937 0 : kfree(in_bus_fmts);
938 0 : return 0;
939 : }
940 :
941 0 : for (i = 0; i < num_in_bus_fmts; i++) {
942 0 : ret = select_bus_fmt_recursive(first_bridge, prev_bridge,
943 : crtc_state, conn_state,
944 0 : in_bus_fmts[i]);
945 0 : if (ret != -ENOTSUPP)
946 : break;
947 : }
948 :
949 0 : if (!ret) {
950 0 : cur_state->input_bus_cfg.format = in_bus_fmts[i];
951 0 : cur_state->output_bus_cfg.format = out_bus_fmt;
952 : }
953 :
954 0 : kfree(in_bus_fmts);
955 0 : return ret;
956 : }
957 :
958 : /*
959 : * This function is called by &drm_atomic_bridge_chain_check() just before
960 : * calling &drm_bridge_funcs.atomic_check() on all elements of the chain.
961 : * It performs bus format negotiation between bridge elements. The negotiation
962 : * happens in reverse order, starting from the last element in the chain up to
963 : * @bridge.
964 : *
965 : * Negotiation starts by retrieving supported output bus formats on the last
966 : * bridge element and testing them one by one. The test is recursive, meaning
967 : * that for each tested output format, the whole chain will be walked backward,
968 : * and each element will have to choose an input bus format that can be
969 : * transcoded to the requested output format. When a bridge element does not
970 : * support transcoding into a specific output format -ENOTSUPP is returned and
971 : * the next bridge element will have to try a different format. If none of the
972 : * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
973 : *
974 : * This implementation is relying on
975 : * &drm_bridge_funcs.atomic_get_output_bus_fmts() and
976 : * &drm_bridge_funcs.atomic_get_input_bus_fmts() to gather supported
977 : * input/output formats.
978 : *
979 : * When &drm_bridge_funcs.atomic_get_output_bus_fmts() is not implemented by
980 : * the last element of the chain, &drm_atomic_bridge_chain_select_bus_fmts()
981 : * tries a single format: &drm_connector.display_info.bus_formats[0] if
982 : * available, MEDIA_BUS_FMT_FIXED otherwise.
983 : *
984 : * When &drm_bridge_funcs.atomic_get_input_bus_fmts() is not implemented,
985 : * &drm_atomic_bridge_chain_select_bus_fmts() skips the negotiation on the
986 : * bridge element that lacks this hook and asks the previous element in the
987 : * chain to try MEDIA_BUS_FMT_FIXED. It's up to bridge drivers to decide what
988 : * to do in that case (fail if they want to enforce bus format negotiation, or
989 : * provide a reasonable default if they need to support pipelines where not
990 : * all elements support bus format negotiation).
991 : */
992 : static int
993 0 : drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
994 : struct drm_crtc_state *crtc_state,
995 : struct drm_connector_state *conn_state)
996 : {
997 0 : struct drm_connector *conn = conn_state->connector;
998 0 : struct drm_encoder *encoder = bridge->encoder;
999 : struct drm_bridge_state *last_bridge_state;
1000 0 : unsigned int i, num_out_bus_fmts = 0;
1001 : struct drm_bridge *last_bridge;
1002 : u32 *out_bus_fmts;
1003 0 : int ret = 0;
1004 :
1005 0 : last_bridge = list_last_entry(&encoder->bridge_chain,
1006 : struct drm_bridge, chain_node);
1007 0 : last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,
1008 : last_bridge);
1009 :
1010 0 : if (last_bridge->funcs->atomic_get_output_bus_fmts) {
1011 0 : const struct drm_bridge_funcs *funcs = last_bridge->funcs;
1012 :
1013 : /*
1014 : * If the driver implements ->atomic_get_output_bus_fmts() it
1015 : * should also implement the atomic state hooks.
1016 : */
1017 0 : if (WARN_ON(!last_bridge_state))
1018 : return -EINVAL;
1019 :
1020 0 : out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,
1021 : last_bridge_state,
1022 : crtc_state,
1023 : conn_state,
1024 : &num_out_bus_fmts);
1025 0 : if (!num_out_bus_fmts)
1026 : return -ENOTSUPP;
1027 0 : else if (!out_bus_fmts)
1028 : return -ENOMEM;
1029 : } else {
1030 0 : num_out_bus_fmts = 1;
1031 0 : out_bus_fmts = kmalloc(sizeof(*out_bus_fmts), GFP_KERNEL);
1032 0 : if (!out_bus_fmts)
1033 : return -ENOMEM;
1034 :
1035 0 : if (conn->display_info.num_bus_formats &&
1036 0 : conn->display_info.bus_formats)
1037 0 : out_bus_fmts[0] = conn->display_info.bus_formats[0];
1038 : else
1039 0 : out_bus_fmts[0] = MEDIA_BUS_FMT_FIXED;
1040 : }
1041 :
1042 0 : for (i = 0; i < num_out_bus_fmts; i++) {
1043 0 : ret = select_bus_fmt_recursive(bridge, last_bridge, crtc_state,
1044 0 : conn_state, out_bus_fmts[i]);
1045 0 : if (ret != -ENOTSUPP)
1046 : break;
1047 : }
1048 :
1049 0 : kfree(out_bus_fmts);
1050 :
1051 0 : return ret;
1052 : }
1053 :
1054 : static void
1055 0 : drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge,
1056 : struct drm_connector *conn,
1057 : struct drm_atomic_state *state)
1058 : {
1059 : struct drm_bridge_state *bridge_state, *next_bridge_state;
1060 : struct drm_bridge *next_bridge;
1061 0 : u32 output_flags = 0;
1062 :
1063 0 : bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
1064 :
1065 : /* No bridge state attached to this bridge => nothing to propagate. */
1066 0 : if (!bridge_state)
1067 : return;
1068 :
1069 0 : next_bridge = drm_bridge_get_next_bridge(bridge);
1070 :
1071 : /*
1072 : * Let's try to apply the most common case here, that is, propagate
1073 : * display_info flags for the last bridge, and propagate the input
1074 : * flags of the next bridge element to the output end of the current
1075 : * bridge when the bridge is not the last one.
1076 : * There are exceptions to this rule, like when signal inversion is
1077 : * happening at the board level, but that's something drivers can deal
1078 : * with from their &drm_bridge_funcs.atomic_check() implementation by
1079 : * simply overriding the flags value we've set here.
1080 : */
1081 0 : if (!next_bridge) {
1082 0 : output_flags = conn->display_info.bus_flags;
1083 : } else {
1084 0 : next_bridge_state = drm_atomic_get_new_bridge_state(state,
1085 : next_bridge);
1086 : /*
1087 : * No bridge state attached to the next bridge, just leave the
1088 : * flags to 0.
1089 : */
1090 0 : if (next_bridge_state)
1091 0 : output_flags = next_bridge_state->input_bus_cfg.flags;
1092 : }
1093 :
1094 0 : bridge_state->output_bus_cfg.flags = output_flags;
1095 :
1096 : /*
1097 : * Propagate the output flags to the input end of the bridge. Again, it's
1098 : * not necessarily what all bridges want, but that's what most of them
1099 : * do, and by doing that by default we avoid forcing drivers to
1100 : * duplicate the "dummy propagation" logic.
1101 : */
1102 0 : bridge_state->input_bus_cfg.flags = output_flags;
1103 : }
1104 :
1105 : /**
1106 : * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1107 : * @bridge: bridge control structure
1108 : * @crtc_state: new CRTC state
1109 : * @conn_state: new connector state
1110 : *
1111 : * First trigger a bus format negotiation before calling
1112 : * &drm_bridge_funcs.atomic_check() (falls back on
1113 : * &drm_bridge_funcs.mode_fixup()) op for all the bridges in the encoder chain,
1114 : * starting from the last bridge to the first. These are called before calling
1115 : * &drm_encoder_helper_funcs.atomic_check()
1116 : *
1117 : * RETURNS:
1118 : * 0 on success, a negative error code on failure
1119 : */
1120 0 : int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
1121 : struct drm_crtc_state *crtc_state,
1122 : struct drm_connector_state *conn_state)
1123 : {
1124 0 : struct drm_connector *conn = conn_state->connector;
1125 : struct drm_encoder *encoder;
1126 : struct drm_bridge *iter;
1127 : int ret;
1128 :
1129 0 : if (!bridge)
1130 : return 0;
1131 :
1132 0 : ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
1133 : conn_state);
1134 0 : if (ret)
1135 : return ret;
1136 :
1137 0 : encoder = bridge->encoder;
1138 0 : list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
1139 : int ret;
1140 :
1141 : /*
1142 : * Bus flags are propagated by default. If a bridge needs to
1143 : * tweak the input bus flags for any reason, it should happen
1144 : * in its &drm_bridge_funcs.atomic_check() implementation such
1145 : * that preceding bridges in the chain can propagate the new
1146 : * bus flags.
1147 : */
1148 0 : drm_atomic_bridge_propagate_bus_flags(iter, conn,
1149 : crtc_state->state);
1150 :
1151 0 : ret = drm_atomic_bridge_check(iter, crtc_state, conn_state);
1152 0 : if (ret)
1153 : return ret;
1154 :
1155 0 : if (iter == bridge)
1156 : break;
1157 : }
1158 :
1159 : return 0;
1160 : }
1161 : EXPORT_SYMBOL(drm_atomic_bridge_chain_check);
1162 :
1163 : /**
1164 : * drm_bridge_detect - check if anything is attached to the bridge output
1165 : * @bridge: bridge control structure
1166 : *
1167 : * If the bridge supports output detection, as reported by the
1168 : * DRM_BRIDGE_OP_DETECT bridge ops flag, call &drm_bridge_funcs.detect for the
1169 : * bridge and return the connection status. Otherwise return
1170 : * connector_status_unknown.
1171 : *
1172 : * RETURNS:
1173 : * The detection status on success, or connector_status_unknown if the bridge
1174 : * doesn't support output detection.
1175 : */
1176 0 : enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge)
1177 : {
1178 0 : if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))
1179 : return connector_status_unknown;
1180 :
1181 0 : return bridge->funcs->detect(bridge);
1182 : }
1183 : EXPORT_SYMBOL_GPL(drm_bridge_detect);
1184 :
1185 : /**
1186 : * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1187 : * @connector
1188 : * @bridge: bridge control structure
1189 : * @connector: the connector to fill with modes
1190 : *
1191 : * If the bridge supports output modes retrieval, as reported by the
1192 : * DRM_BRIDGE_OP_MODES bridge ops flag, call &drm_bridge_funcs.get_modes to
1193 : * fill the connector with all valid modes and return the number of modes
1194 : * added. Otherwise return 0.
1195 : *
1196 : * RETURNS:
1197 : * The number of modes added to the connector.
1198 : */
1199 0 : int drm_bridge_get_modes(struct drm_bridge *bridge,
1200 : struct drm_connector *connector)
1201 : {
1202 0 : if (!(bridge->ops & DRM_BRIDGE_OP_MODES))
1203 : return 0;
1204 :
1205 0 : return bridge->funcs->get_modes(bridge, connector);
1206 : }
1207 : EXPORT_SYMBOL_GPL(drm_bridge_get_modes);
1208 :
1209 : /**
1210 : * drm_bridge_get_edid - get the EDID data of the connected display
1211 : * @bridge: bridge control structure
1212 : * @connector: the connector to read EDID for
1213 : *
1214 : * If the bridge supports output EDID retrieval, as reported by the
1215 : * DRM_BRIDGE_OP_EDID bridge ops flag, call &drm_bridge_funcs.get_edid to
1216 : * get the EDID and return it. Otherwise return NULL.
1217 : *
1218 : * RETURNS:
1219 : * The retrieved EDID on success, or NULL otherwise.
1220 : */
1221 0 : struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
1222 : struct drm_connector *connector)
1223 : {
1224 0 : if (!(bridge->ops & DRM_BRIDGE_OP_EDID))
1225 : return NULL;
1226 :
1227 0 : return bridge->funcs->get_edid(bridge, connector);
1228 : }
1229 : EXPORT_SYMBOL_GPL(drm_bridge_get_edid);
1230 :
1231 : /**
1232 : * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1233 : * @bridge: bridge control structure
1234 : * @cb: hot-plug detection callback
1235 : * @data: data to be passed to the hot-plug detection callback
1236 : *
1237 : * Call &drm_bridge_funcs.hpd_enable if implemented and register the given @cb
1238 : * and @data as hot plug notification callback. From now on the @cb will be
1239 : * called with @data when an output status change is detected by the bridge,
1240 : * until hot plug notification gets disabled with drm_bridge_hpd_disable().
1241 : *
1242 : * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1243 : * bridge->ops. This function shall not be called when the flag is not set.
1244 : *
1245 : * Only one hot plug detection callback can be registered at a time, it is an
1246 : * error to call this function when hot plug detection is already enabled for
1247 : * the bridge.
1248 : */
1249 0 : void drm_bridge_hpd_enable(struct drm_bridge *bridge,
1250 : void (*cb)(void *data,
1251 : enum drm_connector_status status),
1252 : void *data)
1253 : {
1254 0 : if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
1255 : return;
1256 :
1257 0 : mutex_lock(&bridge->hpd_mutex);
1258 :
1259 0 : if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))
1260 : goto unlock;
1261 :
1262 0 : bridge->hpd_cb = cb;
1263 0 : bridge->hpd_data = data;
1264 :
1265 0 : if (bridge->funcs->hpd_enable)
1266 0 : bridge->funcs->hpd_enable(bridge);
1267 :
1268 : unlock:
1269 0 : mutex_unlock(&bridge->hpd_mutex);
1270 : }
1271 : EXPORT_SYMBOL_GPL(drm_bridge_hpd_enable);
1272 :
1273 : /**
1274 : * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1275 : * @bridge: bridge control structure
1276 : *
1277 : * Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot
1278 : * plug detection callback previously registered with drm_bridge_hpd_enable().
1279 : * Once this function returns the callback will not be called by the bridge
1280 : * when an output status change occurs.
1281 : *
1282 : * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1283 : * bridge->ops. This function shall not be called when the flag is not set.
1284 : */
1285 0 : void drm_bridge_hpd_disable(struct drm_bridge *bridge)
1286 : {
1287 0 : if (!(bridge->ops & DRM_BRIDGE_OP_HPD))
1288 : return;
1289 :
1290 0 : mutex_lock(&bridge->hpd_mutex);
1291 0 : if (bridge->funcs->hpd_disable)
1292 0 : bridge->funcs->hpd_disable(bridge);
1293 :
1294 0 : bridge->hpd_cb = NULL;
1295 0 : bridge->hpd_data = NULL;
1296 0 : mutex_unlock(&bridge->hpd_mutex);
1297 : }
1298 : EXPORT_SYMBOL_GPL(drm_bridge_hpd_disable);
1299 :
1300 : /**
1301 : * drm_bridge_hpd_notify - notify hot plug detection events
1302 : * @bridge: bridge control structure
1303 : * @status: output connection status
1304 : *
1305 : * Bridge drivers shall call this function to report hot plug events when they
1306 : * detect a change in the output status, when hot plug detection has been
1307 : * enabled by drm_bridge_hpd_enable().
1308 : *
1309 : * This function shall be called in a context that can sleep.
1310 : */
1311 0 : void drm_bridge_hpd_notify(struct drm_bridge *bridge,
1312 : enum drm_connector_status status)
1313 : {
1314 0 : mutex_lock(&bridge->hpd_mutex);
1315 0 : if (bridge->hpd_cb)
1316 0 : bridge->hpd_cb(bridge->hpd_data, status);
1317 0 : mutex_unlock(&bridge->hpd_mutex);
1318 0 : }
1319 : EXPORT_SYMBOL_GPL(drm_bridge_hpd_notify);
1320 :
1321 : #ifdef CONFIG_OF
1322 : /**
1323 : * of_drm_find_bridge - find the bridge corresponding to the device node in
1324 : * the global bridge list
1325 : *
1326 : * @np: device node
1327 : *
1328 : * RETURNS:
1329 : * drm_bridge control struct on success, NULL on failure
1330 : */
1331 : struct drm_bridge *of_drm_find_bridge(struct device_node *np)
1332 : {
1333 : struct drm_bridge *bridge;
1334 :
1335 : mutex_lock(&bridge_lock);
1336 :
1337 : list_for_each_entry(bridge, &bridge_list, list) {
1338 : if (bridge->of_node == np) {
1339 : mutex_unlock(&bridge_lock);
1340 : return bridge;
1341 : }
1342 : }
1343 :
1344 : mutex_unlock(&bridge_lock);
1345 : return NULL;
1346 : }
1347 : EXPORT_SYMBOL(of_drm_find_bridge);
1348 : #endif
1349 :
1350 : #ifdef CONFIG_DEBUG_FS
1351 : static int drm_bridge_chains_info(struct seq_file *m, void *data)
1352 : {
1353 : struct drm_debugfs_entry *entry = m->private;
1354 : struct drm_device *dev = entry->dev;
1355 : struct drm_printer p = drm_seq_file_printer(m);
1356 : struct drm_mode_config *config = &dev->mode_config;
1357 : struct drm_encoder *encoder;
1358 : unsigned int bridge_idx = 0;
1359 :
1360 : list_for_each_entry(encoder, &config->encoder_list, head) {
1361 : struct drm_bridge *bridge;
1362 :
1363 : drm_printf(&p, "encoder[%u]\n", encoder->base.id);
1364 :
1365 : drm_for_each_bridge_in_chain(encoder, bridge) {
1366 : drm_printf(&p, "\tbridge[%u] type: %u, ops: %#x",
1367 : bridge_idx, bridge->type, bridge->ops);
1368 :
1369 : #ifdef CONFIG_OF
1370 : if (bridge->of_node)
1371 : drm_printf(&p, ", OF: %pOFfc", bridge->of_node);
1372 : #endif
1373 :
1374 : drm_printf(&p, "\n");
1375 :
1376 : bridge_idx++;
1377 : }
1378 : }
1379 :
1380 : return 0;
1381 : }
1382 :
1383 : static const struct drm_debugfs_info drm_bridge_debugfs_list[] = {
1384 : { "bridge_chains", drm_bridge_chains_info, 0 },
1385 : };
1386 :
1387 : void drm_bridge_debugfs_init(struct drm_minor *minor)
1388 : {
1389 : drm_debugfs_add_files(minor->dev, drm_bridge_debugfs_list,
1390 : ARRAY_SIZE(drm_bridge_debugfs_list));
1391 : }
1392 : #endif
1393 :
1394 : MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
1395 : MODULE_DESCRIPTION("DRM bridge infrastructure");
1396 : MODULE_LICENSE("GPL and additional rights");
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