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1/*2 * Copyright (c) 2016 Intel Corporation3 *4 * Permission to use, copy, modify, distribute, and sell this software and its5 * documentation for any purpose is hereby granted without fee, provided that6 * the above copyright notice appear in all copies and that both that copyright7 * notice and this permission notice appear in supporting documentation, and8 * that the name of the copyright holders not be used in advertising or9 * publicity pertaining to distribution of the software without specific,10 * written prior permission.  The copyright holders make no representations11 * about the suitability of this software for any purpose.  It is provided "as12 * 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 NO16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE20 * 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 35struct device_node;36 37struct drm_bridge;38struct drm_bridge_timings;39struct drm_connector;40struct drm_display_info;41struct drm_minor;42struct drm_panel;43struct edid;44struct i2c_adapter;45 46/**47 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach48 */49enum drm_bridge_attach_flags {50	/**51	 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge52	 * shall not create a drm_connector.53	 */54	DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),55};56 57/**58 * struct drm_bridge_funcs - drm_bridge control functions59 */60struct drm_bridge_funcs {61	/**62	 * @attach:63	 *64	 * This callback is invoked whenever our bridge is being attached to a65	 * &drm_encoder. The flags argument tunes the behaviour of the attach66	 * operation (see DRM_BRIDGE_ATTACH_*).67	 *68	 * The @attach callback is optional.69	 *70	 * RETURNS:71	 *72	 * Zero on success, error code on failure.73	 */74	int (*attach)(struct drm_bridge *bridge,75		      enum drm_bridge_attach_flags flags);76 77	/**78	 * @detach:79	 *80	 * This callback is invoked whenever our bridge is being detached from a81	 * &drm_encoder.82	 *83	 * The @detach callback is optional.84	 */85	void (*detach)(struct drm_bridge *bridge);86 87	/**88	 * @mode_valid:89	 *90	 * This callback is used to check if a specific mode is valid in this91	 * bridge. This should be implemented if the bridge has some sort of92	 * restriction in the modes it can display. For example, a given bridge93	 * may be responsible to set a clock value. If the clock can not94	 * produce all the values for the available modes then this callback95	 * can be used to restrict the number of modes to only the ones that96	 * can be displayed.97	 *98	 * This hook is used by the probe helpers to filter the mode list in99	 * drm_helper_probe_single_connector_modes(), and it is used by the100	 * atomic helpers to validate modes supplied by userspace in101	 * drm_atomic_helper_check_modeset().102	 *103	 * The @mode_valid callback is optional.104	 *105	 * NOTE:106	 *107	 * Since this function is both called from the check phase of an atomic108	 * commit, and the mode validation in the probe paths it is not allowed109	 * to look at anything else but the passed-in mode, and validate it110	 * against configuration-invariant hardware constraints. Any further111	 * limits which depend upon the configuration can only be checked in112	 * @mode_fixup.113	 *114	 * RETURNS:115	 *116	 * drm_mode_status Enum117	 */118	enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,119					   const struct drm_display_info *info,120					   const struct drm_display_mode *mode);121 122	/**123	 * @mode_fixup:124	 *125	 * This callback is used to validate and adjust a mode. The parameter126	 * mode is the display mode that should be fed to the next element in127	 * the display chain, either the final &drm_connector or the next128	 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge129	 * requires. It can be modified by this callback and does not need to130	 * match mode. See also &drm_crtc_state.adjusted_mode for more details.131	 *132	 * This is the only hook that allows a bridge to reject a modeset. If133	 * this function passes all other callbacks must succeed for this134	 * configuration.135	 *136	 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()137	 * is not called when &drm_bridge_funcs.atomic_check() is implemented,138	 * so only one of them should be provided.139	 *140	 * NOTE:141	 *142	 * This function is called in the check phase of atomic modesets, which143	 * can be aborted for any reason (including on userspace's request to144	 * just check whether a configuration would be possible). Drivers MUST145	 * NOT touch any persistent state (hardware or software) or data146	 * structures except the passed in @state parameter.147	 *148	 * Also beware that userspace can request its own custom modes, neither149	 * core nor helpers filter modes to the list of probe modes reported by150	 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure151	 * that modes are filtered consistently put any bridge constraints and152	 * limits checks into @mode_valid.153	 *154	 * RETURNS:155	 *156	 * True if an acceptable configuration is possible, false if the modeset157	 * operation should be rejected.158	 */159	bool (*mode_fixup)(struct drm_bridge *bridge,160			   const struct drm_display_mode *mode,161			   struct drm_display_mode *adjusted_mode);162	/**163	 * @disable:164	 *165	 * This callback should disable the bridge. It is called right before166	 * the preceding element in the display pipe is disabled. If the167	 * preceding element is a bridge this means it's called before that168	 * bridge's @disable vfunc. If the preceding element is a &drm_encoder169	 * it's called right before the &drm_encoder_helper_funcs.disable,170	 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms171	 * hook.172	 *173	 * The bridge can assume that the display pipe (i.e. clocks and timing174	 * signals) feeding it is still running when this callback is called.175	 *176	 * The @disable callback is optional.177	 *178	 * NOTE:179	 *180	 * This is deprecated, do not use!181	 * New drivers shall use &drm_bridge_funcs.atomic_disable.182	 */183	void (*disable)(struct drm_bridge *bridge);184 185	/**186	 * @post_disable:187	 *188	 * This callback should disable the bridge. It is called right after the189	 * preceding element in the display pipe is disabled. If the preceding190	 * element is a bridge this means it's called after that bridge's191	 * @post_disable function. If the preceding element is a &drm_encoder192	 * it's called right after the encoder's193	 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare194	 * or &drm_encoder_helper_funcs.dpms hook.195	 *196	 * The bridge must assume that the display pipe (i.e. clocks and timing197	 * signals) feeding it is no longer running when this callback is198	 * called.199	 *200	 * The @post_disable callback is optional.201	 *202	 * NOTE:203	 *204	 * This is deprecated, do not use!205	 * New drivers shall use &drm_bridge_funcs.atomic_post_disable.206	 */207	void (*post_disable)(struct drm_bridge *bridge);208 209	/**210	 * @mode_set:211	 *212	 * This callback should set the given mode on the bridge. It is called213	 * after the @mode_set callback for the preceding element in the display214	 * pipeline has been called already. If the bridge is the first element215	 * then this would be &drm_encoder_helper_funcs.mode_set. The display216	 * pipe (i.e.  clocks and timing signals) is off when this function is217	 * called.218	 *219	 * The adjusted_mode parameter is the mode output by the CRTC for the220	 * first bridge in the chain. It can be different from the mode221	 * parameter that contains the desired mode for the connector at the end222	 * of the bridges chain, for instance when the first bridge in the chain223	 * performs scaling. The adjusted mode is mostly useful for the first224	 * bridge in the chain and is likely irrelevant for the other bridges.225	 *226	 * For atomic drivers the adjusted_mode is the mode stored in227	 * &drm_crtc_state.adjusted_mode.228	 *229	 * NOTE:230	 *231	 * This is deprecated, do not use!232	 * New drivers shall set their mode in the233	 * &drm_bridge_funcs.atomic_enable operation.234	 */235	void (*mode_set)(struct drm_bridge *bridge,236			 const struct drm_display_mode *mode,237			 const struct drm_display_mode *adjusted_mode);238	/**239	 * @pre_enable:240	 *241	 * This callback should enable the bridge. It is called right before242	 * the preceding element in the display pipe is enabled. If the243	 * preceding element is a bridge this means it's called before that244	 * bridge's @pre_enable function. If the preceding element is a245	 * &drm_encoder it's called right before the encoder's246	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or247	 * &drm_encoder_helper_funcs.dpms hook.248	 *249	 * The display pipe (i.e. clocks and timing signals) feeding this bridge250	 * will not yet be running when this callback is called. The bridge must251	 * not enable the display link feeding the next bridge in the chain (if252	 * there is one) when this callback is called.253	 *254	 * The @pre_enable callback is optional.255	 *256	 * NOTE:257	 *258	 * This is deprecated, do not use!259	 * New drivers shall use &drm_bridge_funcs.atomic_pre_enable.260	 */261	void (*pre_enable)(struct drm_bridge *bridge);262 263	/**264	 * @enable:265	 *266	 * This callback should enable the bridge. It is called right after267	 * the preceding element in the display pipe is enabled. If the268	 * preceding element is a bridge this means it's called after that269	 * bridge's @enable function. If the preceding element is a270	 * &drm_encoder it's called right after the encoder's271	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or272	 * &drm_encoder_helper_funcs.dpms hook.273	 *274	 * The bridge can assume that the display pipe (i.e. clocks and timing275	 * signals) feeding it is running when this callback is called. This276	 * callback must enable the display link feeding the next bridge in the277	 * chain if there is one.278	 *279	 * The @enable callback is optional.280	 *281	 * NOTE:282	 *283	 * This is deprecated, do not use!284	 * New drivers shall use &drm_bridge_funcs.atomic_enable.285	 */286	void (*enable)(struct drm_bridge *bridge);287 288	/**289	 * @atomic_pre_enable:290	 *291	 * This callback should enable the bridge. It is called right before292	 * the preceding element in the display pipe is enabled. If the293	 * preceding element is a bridge this means it's called before that294	 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding295	 * element is a &drm_encoder it's called right before the encoder's296	 * &drm_encoder_helper_funcs.atomic_enable hook.297	 *298	 * The display pipe (i.e. clocks and timing signals) feeding this bridge299	 * will not yet be running when this callback is called. The bridge must300	 * not enable the display link feeding the next bridge in the chain (if301	 * there is one) when this callback is called.302	 *303	 * The @atomic_pre_enable callback is optional.304	 */305	void (*atomic_pre_enable)(struct drm_bridge *bridge,306				  struct drm_bridge_state *old_bridge_state);307 308	/**309	 * @atomic_enable:310	 *311	 * This callback should enable the bridge. It is called right after312	 * the preceding element in the display pipe is enabled. If the313	 * preceding element is a bridge this means it's called after that314	 * bridge's @atomic_enable or @enable function. If the preceding element315	 * is a &drm_encoder it's called right after the encoder's316	 * &drm_encoder_helper_funcs.atomic_enable hook.317	 *318	 * The bridge can assume that the display pipe (i.e. clocks and timing319	 * signals) feeding it is running when this callback is called. This320	 * callback must enable the display link feeding the next bridge in the321	 * chain if there is one.322	 *323	 * The @atomic_enable callback is optional.324	 */325	void (*atomic_enable)(struct drm_bridge *bridge,326			      struct drm_bridge_state *old_bridge_state);327	/**328	 * @atomic_disable:329	 *330	 * This callback should disable the bridge. It is called right before331	 * the preceding element in the display pipe is disabled. If the332	 * preceding element is a bridge this means it's called before that333	 * bridge's @atomic_disable or @disable vfunc. If the preceding element334	 * is a &drm_encoder it's called right before the335	 * &drm_encoder_helper_funcs.atomic_disable hook.336	 *337	 * The bridge can assume that the display pipe (i.e. clocks and timing338	 * signals) feeding it is still running when this callback is called.339	 *340	 * The @atomic_disable callback is optional.341	 */342	void (*atomic_disable)(struct drm_bridge *bridge,343			       struct drm_bridge_state *old_bridge_state);344 345	/**346	 * @atomic_post_disable:347	 *348	 * This callback should disable the bridge. It is called right after the349	 * preceding element in the display pipe is disabled. If the preceding350	 * element is a bridge this means it's called after that bridge's351	 * @atomic_post_disable or @post_disable function. If the preceding352	 * element is a &drm_encoder it's called right after the encoder's353	 * &drm_encoder_helper_funcs.atomic_disable hook.354	 *355	 * The bridge must assume that the display pipe (i.e. clocks and timing356	 * signals) feeding it is no longer running when this callback is357	 * called.358	 *359	 * The @atomic_post_disable callback is optional.360	 */361	void (*atomic_post_disable)(struct drm_bridge *bridge,362				    struct drm_bridge_state *old_bridge_state);363 364	/**365	 * @atomic_duplicate_state:366	 *367	 * Duplicate the current bridge state object (which is guaranteed to be368	 * non-NULL).369	 *370	 * The atomic_duplicate_state hook is mandatory if the bridge371	 * implements any of the atomic hooks, and should be left unassigned372	 * otherwise. For bridges that don't subclass &drm_bridge_state, the373	 * drm_atomic_helper_bridge_duplicate_state() helper function shall be374	 * used to implement this hook.375	 *376	 * RETURNS:377	 * A valid drm_bridge_state object or NULL if the allocation fails.378	 */379	struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);380 381	/**382	 * @atomic_destroy_state:383	 *384	 * Destroy a bridge state object previously allocated by385	 * &drm_bridge_funcs.atomic_duplicate_state().386	 *387	 * The atomic_destroy_state hook is mandatory if the bridge implements388	 * any of the atomic hooks, and should be left unassigned otherwise.389	 * For bridges that don't subclass &drm_bridge_state, the390	 * drm_atomic_helper_bridge_destroy_state() helper function shall be391	 * used to implement this hook.392	 */393	void (*atomic_destroy_state)(struct drm_bridge *bridge,394				     struct drm_bridge_state *state);395 396	/**397	 * @atomic_get_output_bus_fmts:398	 *399	 * Return the supported bus formats on the output end of a bridge.400	 * The returned array must be allocated with kmalloc() and will be401	 * freed by the caller. If the allocation fails, NULL should be402	 * returned. num_output_fmts must be set to the returned array size.403	 * Formats listed in the returned array should be listed in decreasing404	 * preference order (the core will try all formats until it finds one405	 * that works).406	 *407	 * This method is only called on the last element of the bridge chain408	 * as part of the bus format negotiation process that happens in409	 * &drm_atomic_bridge_chain_select_bus_fmts().410	 * This method is optional. When not implemented, the core will411	 * fall back to &drm_connector.display_info.bus_formats[0] if412	 * &drm_connector.display_info.num_bus_formats > 0,413	 * or to MEDIA_BUS_FMT_FIXED otherwise.414	 */415	u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,416					   struct drm_bridge_state *bridge_state,417					   struct drm_crtc_state *crtc_state,418					   struct drm_connector_state *conn_state,419					   unsigned int *num_output_fmts);420 421	/**422	 * @atomic_get_input_bus_fmts:423	 *424	 * Return the supported bus formats on the input end of a bridge for425	 * a specific output bus format.426	 *427	 * The returned array must be allocated with kmalloc() and will be428	 * freed by the caller. If the allocation fails, NULL should be429	 * returned. num_input_fmts must be set to the returned array size.430	 * Formats listed in the returned array should be listed in decreasing431	 * preference order (the core will try all formats until it finds one432	 * that works). When the format is not supported NULL should be433	 * returned and num_input_fmts should be set to 0.434	 *435	 * This method is called on all elements of the bridge chain as part of436	 * the bus format negotiation process that happens in437	 * drm_atomic_bridge_chain_select_bus_fmts().438	 * This method is optional. When not implemented, the core will bypass439	 * bus format negotiation on this element of the bridge without440	 * failing, and the previous element in the chain will be passed441	 * MEDIA_BUS_FMT_FIXED as its output bus format.442	 *443	 * Bridge drivers that need to support being linked to bridges that are444	 * not supporting bus format negotiation should handle the445	 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a446	 * sensible default value or extracting this information from somewhere447	 * else (FW property, &drm_display_mode, &drm_display_info, ...)448	 *449	 * Note: Even if input format selection on the first bridge has no450	 * impact on the negotiation process (bus format negotiation stops once451	 * we reach the first element of the chain), drivers are expected to452	 * return accurate input formats as the input format may be used to453	 * configure the CRTC output appropriately.454	 */455	u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,456					  struct drm_bridge_state *bridge_state,457					  struct drm_crtc_state *crtc_state,458					  struct drm_connector_state *conn_state,459					  u32 output_fmt,460					  unsigned int *num_input_fmts);461 462	/**463	 * @atomic_check:464	 *465	 * This method is responsible for checking bridge state correctness.466	 * It can also check the state of the surrounding components in chain467	 * to make sure the whole pipeline can work properly.468	 *469	 * &drm_bridge_funcs.atomic_check() hooks are called in reverse470	 * order (from the last to the first bridge).471	 *472	 * This method is optional. &drm_bridge_funcs.mode_fixup() is not473	 * called when &drm_bridge_funcs.atomic_check() is implemented, so only474	 * one of them should be provided.475	 *476	 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or477	 * &drm_bridge_state.output_bus_cfg.flags it should happen in478	 * this function. By default the &drm_bridge_state.output_bus_cfg.flags479	 * field is set to the next bridge480	 * &drm_bridge_state.input_bus_cfg.flags value or481	 * &drm_connector.display_info.bus_flags if the bridge is the last482	 * element in the chain.483	 *484	 * RETURNS:485	 * zero if the check passed, a negative error code otherwise.486	 */487	int (*atomic_check)(struct drm_bridge *bridge,488			    struct drm_bridge_state *bridge_state,489			    struct drm_crtc_state *crtc_state,490			    struct drm_connector_state *conn_state);491 492	/**493	 * @atomic_reset:494	 *495	 * Reset the bridge to a predefined state (or retrieve its current496	 * state) and return a &drm_bridge_state object matching this state.497	 * This function is called at attach time.498	 *499	 * The atomic_reset hook is mandatory if the bridge implements any of500	 * the atomic hooks, and should be left unassigned otherwise. For501	 * bridges that don't subclass &drm_bridge_state, the502	 * drm_atomic_helper_bridge_reset() helper function shall be used to503	 * implement this hook.504	 *505	 * Note that the atomic_reset() semantics is not exactly matching the506	 * reset() semantics found on other components (connector, plane, ...).507	 *508	 * 1. The reset operation happens when the bridge is attached, not when509	 *    drm_mode_config_reset() is called510	 * 2. It's meant to be used exclusively on bridges that have been511	 *    converted to the ATOMIC API512	 *513	 * RETURNS:514	 * A valid drm_bridge_state object in case of success, an ERR_PTR()515	 * giving the reason of the failure otherwise.516	 */517	struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);518 519	/**520	 * @detect:521	 *522	 * Check if anything is attached to the bridge output.523	 *524	 * This callback is optional, if not implemented the bridge will be525	 * considered as always having a component attached to its output.526	 * Bridges that implement this callback shall set the527	 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.528	 *529	 * RETURNS:530	 *531	 * drm_connector_status indicating the bridge output status.532	 */533	enum drm_connector_status (*detect)(struct drm_bridge *bridge);534 535	/**536	 * @get_modes:537	 *538	 * Fill all modes currently valid for the sink into the &drm_connector539	 * with drm_mode_probed_add().540	 *541	 * The @get_modes callback is mostly intended to support non-probeable542	 * displays such as many fixed panels. Bridges that support reading543	 * EDID shall leave @get_modes unimplemented and implement the544	 * &drm_bridge_funcs->edid_read callback instead.545	 *546	 * This callback is optional. Bridges that implement it shall set the547	 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.548	 *549	 * The connector parameter shall be used for the sole purpose of550	 * filling modes, and shall not be stored internally by bridge drivers551	 * for future usage.552	 *553	 * RETURNS:554	 *555	 * The number of modes added by calling drm_mode_probed_add().556	 */557	int (*get_modes)(struct drm_bridge *bridge,558			 struct drm_connector *connector);559 560	/**561	 * @edid_read:562	 *563	 * Read the EDID data of the connected display.564	 *565	 * The @edid_read callback is the preferred way of reporting mode566	 * information for a display connected to the bridge output. Bridges567	 * that support reading EDID shall implement this callback and leave568	 * the @get_modes callback unimplemented.569	 *570	 * The caller of this operation shall first verify the output571	 * connection status and refrain from reading EDID from a disconnected572	 * output.573	 *574	 * This callback is optional. Bridges that implement it shall set the575	 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.576	 *577	 * The connector parameter shall be used for the sole purpose of EDID578	 * retrieval, and shall not be stored internally by bridge drivers for579	 * future usage.580	 *581	 * RETURNS:582	 *583	 * An edid structure newly allocated with drm_edid_alloc() or returned584	 * from drm_edid_read() family of functions on success, or NULL585	 * otherwise. The caller is responsible for freeing the returned edid586	 * structure with drm_edid_free().587	 */588	const struct drm_edid *(*edid_read)(struct drm_bridge *bridge,589					    struct drm_connector *connector);590 591	/**592	 * @hpd_notify:593	 *594	 * Notify the bridge of hot plug detection.595	 *596	 * This callback is optional, it may be implemented by bridges that597	 * need to be notified of display connection or disconnection for598	 * internal reasons. One use case is to reset the internal state of CEC599	 * controllers for HDMI bridges.600	 */601	void (*hpd_notify)(struct drm_bridge *bridge,602			   enum drm_connector_status status);603 604	/**605	 * @hpd_enable:606	 *607	 * Enable hot plug detection. From now on the bridge shall call608	 * drm_bridge_hpd_notify() each time a change is detected in the output609	 * connection status, until hot plug detection gets disabled with610	 * @hpd_disable.611	 *612	 * This callback is optional and shall only be implemented by bridges613	 * that support hot-plug notification without polling. Bridges that614	 * implement it shall also implement the @hpd_disable callback and set615	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.616	 */617	void (*hpd_enable)(struct drm_bridge *bridge);618 619	/**620	 * @hpd_disable:621	 *622	 * Disable hot plug detection. Once this function returns the bridge623	 * shall not call drm_bridge_hpd_notify() when a change in the output624	 * connection status occurs.625	 *626	 * This callback is optional and shall only be implemented by bridges627	 * that support hot-plug notification without polling. Bridges that628	 * implement it shall also implement the @hpd_enable callback and set629	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.630	 */631	void (*hpd_disable)(struct drm_bridge *bridge);632 633	/**634	 * @hdmi_tmds_char_rate_valid:635	 *636	 * Check whether a particular TMDS character rate is supported by the637	 * driver.638	 *639	 * This callback is optional and should only be implemented by the640	 * bridges that take part in the HDMI connector implementation. Bridges641	 * that implement it shall set the DRM_BRIDGE_OP_HDMI flag in their642	 * &drm_bridge->ops.643	 *644	 * Returns:645	 *646	 * Either &drm_mode_status.MODE_OK or one of the failure reasons647	 * in &enum drm_mode_status.648	 */649	enum drm_mode_status650	(*hdmi_tmds_char_rate_valid)(const struct drm_bridge *bridge,651				     const struct drm_display_mode *mode,652				     unsigned long long tmds_rate);653 654	/**655	 * @hdmi_clear_infoframe:656	 *657	 * This callback clears the infoframes in the hardware during commit.658	 * It will be called multiple times, once for every disabled infoframe659	 * type.660	 *661	 * This callback is optional but it must be implemented by bridges that662	 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.663	 */664	int (*hdmi_clear_infoframe)(struct drm_bridge *bridge,665				    enum hdmi_infoframe_type type);666	/**667	 * @hdmi_write_infoframe:668	 *669	 * Program the infoframe into the hardware. It will be called multiple670	 * times, once for every updated infoframe type.671	 *672	 * This callback is optional but it must be implemented by bridges that673	 * set the DRM_BRIDGE_OP_HDMI flag in their &drm_bridge->ops.674	 */675	int (*hdmi_write_infoframe)(struct drm_bridge *bridge,676				    enum hdmi_infoframe_type type,677				    const u8 *buffer, size_t len);678 679	/**680	 * @debugfs_init:681	 *682	 * Allows bridges to create bridge-specific debugfs files.683	 */684	void (*debugfs_init)(struct drm_bridge *bridge, struct dentry *root);685};686 687/**688 * struct drm_bridge_timings - timing information for the bridge689 */690struct drm_bridge_timings {691	/**692	 * @input_bus_flags:693	 *694	 * Tells what additional settings for the pixel data on the bus695	 * this bridge requires (like pixel signal polarity). See also696	 * &drm_display_info->bus_flags.697	 */698	u32 input_bus_flags;699	/**700	 * @setup_time_ps:701	 *702	 * Defines the time in picoseconds the input data lines must be703	 * stable before the clock edge.704	 */705	u32 setup_time_ps;706	/**707	 * @hold_time_ps:708	 *709	 * Defines the time in picoseconds taken for the bridge to sample the710	 * input signal after the clock edge.711	 */712	u32 hold_time_ps;713	/**714	 * @dual_link:715	 *716	 * True if the bus operates in dual-link mode. The exact meaning is717	 * dependent on the bus type. For LVDS buses, this indicates that even-718	 * and odd-numbered pixels are received on separate links.719	 */720	bool dual_link;721};722 723/**724 * enum drm_bridge_ops - Bitmask of operations supported by the bridge725 */726enum drm_bridge_ops {727	/**728	 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to729	 * its output. Bridges that set this flag shall implement the730	 * &drm_bridge_funcs->detect callback.731	 */732	DRM_BRIDGE_OP_DETECT = BIT(0),733	/**734	 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display735	 * connected to its output. Bridges that set this flag shall implement736	 * the &drm_bridge_funcs->edid_read callback.737	 */738	DRM_BRIDGE_OP_EDID = BIT(1),739	/**740	 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug741	 * without requiring polling. Bridges that set this flag shall742	 * implement the &drm_bridge_funcs->hpd_enable and743	 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling744	 * and disabling hot-plug detection dynamically.745	 */746	DRM_BRIDGE_OP_HPD = BIT(2),747	/**748	 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported749	 * by the display at its output. This does not include reading EDID750	 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set751	 * this flag shall implement the &drm_bridge_funcs->get_modes callback.752	 */753	DRM_BRIDGE_OP_MODES = BIT(3),754	/**755	 * @DRM_BRIDGE_OP_HDMI: The bridge provides HDMI connector operations,756	 * including infoframes support. Bridges that set this flag must757	 * implement the &drm_bridge_funcs->write_infoframe callback.758	 *759	 * Note: currently there can be at most one bridge in a chain that sets760	 * this bit. This is to simplify corresponding glue code in connector761	 * drivers.762	 */763	DRM_BRIDGE_OP_HDMI = BIT(4),764};765 766/**767 * struct drm_bridge - central DRM bridge control structure768 */769struct drm_bridge {770	/** @base: inherit from &drm_private_object */771	struct drm_private_obj base;772	/** @dev: DRM device this bridge belongs to */773	struct drm_device *dev;774	/** @encoder: encoder to which this bridge is connected */775	struct drm_encoder *encoder;776	/** @chain_node: used to form a bridge chain */777	struct list_head chain_node;778	/** @of_node: device node pointer to the bridge */779	struct device_node *of_node;780	/** @list: to keep track of all added bridges */781	struct list_head list;782	/**783	 * @timings:784	 *785	 * the timing specification for the bridge, if any (may be NULL)786	 */787	const struct drm_bridge_timings *timings;788	/** @funcs: control functions */789	const struct drm_bridge_funcs *funcs;790	/** @driver_private: pointer to the bridge driver's internal context */791	void *driver_private;792	/** @ops: bitmask of operations supported by the bridge */793	enum drm_bridge_ops ops;794	/**795	 * @type: Type of the connection at the bridge output796	 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this797	 * identifies the type of connected display.798	 */799	int type;800	/**801	 * @interlace_allowed: Indicate that the bridge can handle interlaced802	 * modes.803	 */804	bool interlace_allowed;805	/**806	 * @pre_enable_prev_first: The bridge requires that the prev807	 * bridge @pre_enable function is called before its @pre_enable,808	 * and conversely for post_disable. This is most frequently a809	 * requirement for DSI devices which need the host to be initialised810	 * before the peripheral.811	 */812	bool pre_enable_prev_first;813	/**814	 * @ddc: Associated I2C adapter for DDC access, if any.815	 */816	struct i2c_adapter *ddc;817	/** private: */818	/**819	 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.820	 */821	struct mutex hpd_mutex;822	/**823	 * @hpd_cb: Hot plug detection callback, registered with824	 * drm_bridge_hpd_enable().825	 */826	void (*hpd_cb)(void *data, enum drm_connector_status status);827	/**828	 * @hpd_data: Private data passed to the Hot plug detection callback829	 * @hpd_cb.830	 */831	void *hpd_data;832 833	/**834	 * @vendor: Vendor of the product to be used for the SPD InfoFrame835	 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.836	 */837	const char *vendor;838 839	/**840	 * @product: Name of the product to be used for the SPD InfoFrame841	 * generation. This is required if @DRM_BRIDGE_OP_HDMI is set.842	 */843	const char *product;844 845	/**846	 * @supported_formats: Bitmask of @hdmi_colorspace listing supported847	 * output formats. This is only relevant if @DRM_BRIDGE_OP_HDMI is set.848	 */849	unsigned int supported_formats;850 851	/**852	 * @max_bpc: Maximum bits per char the HDMI bridge supports. Allowed853	 * values are 8, 10 and 12. This is only relevant if854	 * @DRM_BRIDGE_OP_HDMI is set.855	 */856	unsigned int max_bpc;857};858 859static inline struct drm_bridge *860drm_priv_to_bridge(struct drm_private_obj *priv)861{862	return container_of(priv, struct drm_bridge, base);863}864 865void drm_bridge_add(struct drm_bridge *bridge);866int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);867void drm_bridge_remove(struct drm_bridge *bridge);868int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,869		      struct drm_bridge *previous,870		      enum drm_bridge_attach_flags flags);871 872#ifdef CONFIG_OF873struct drm_bridge *of_drm_find_bridge(struct device_node *np);874#else875static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)876{877	return NULL;878}879#endif880 881/**882 * drm_bridge_get_next_bridge() - Get the next bridge in the chain883 * @bridge: bridge object884 *885 * RETURNS:886 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.887 */888static inline struct drm_bridge *889drm_bridge_get_next_bridge(struct drm_bridge *bridge)890{891	if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))892		return NULL;893 894	return list_next_entry(bridge, chain_node);895}896 897/**898 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain899 * @bridge: bridge object900 *901 * RETURNS:902 * the previous bridge in the chain, or NULL if @bridge is the first.903 */904static inline struct drm_bridge *905drm_bridge_get_prev_bridge(struct drm_bridge *bridge)906{907	if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))908		return NULL;909 910	return list_prev_entry(bridge, chain_node);911}912 913/**914 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain915 * @encoder: encoder object916 *917 * RETURNS:918 * the first bridge in the chain, or NULL if @encoder has no bridge attached919 * to it.920 */921static inline struct drm_bridge *922drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)923{924	return list_first_entry_or_null(&encoder->bridge_chain,925					struct drm_bridge, chain_node);926}927 928/**929 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain930 * @encoder: the encoder to iterate bridges on931 * @bridge: a bridge pointer updated to point to the current bridge at each932 *	    iteration933 *934 * Iterate over all bridges present in the bridge chain attached to @encoder.935 */936#define drm_for_each_bridge_in_chain(encoder, bridge)			\937	list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)938 939enum drm_mode_status940drm_bridge_chain_mode_valid(struct drm_bridge *bridge,941			    const struct drm_display_info *info,942			    const struct drm_display_mode *mode);943void drm_bridge_chain_mode_set(struct drm_bridge *bridge,944			       const struct drm_display_mode *mode,945			       const struct drm_display_mode *adjusted_mode);946 947int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,948				  struct drm_crtc_state *crtc_state,949				  struct drm_connector_state *conn_state);950void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,951				     struct drm_atomic_state *state);952void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,953					  struct drm_atomic_state *state);954void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,955					struct drm_atomic_state *state);956void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,957				    struct drm_atomic_state *state);958 959u32 *960drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,961					struct drm_bridge_state *bridge_state,962					struct drm_crtc_state *crtc_state,963					struct drm_connector_state *conn_state,964					u32 output_fmt,965					unsigned int *num_input_fmts);966 967enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);968int drm_bridge_get_modes(struct drm_bridge *bridge,969			 struct drm_connector *connector);970const struct drm_edid *drm_bridge_edid_read(struct drm_bridge *bridge,971					    struct drm_connector *connector);972void drm_bridge_hpd_enable(struct drm_bridge *bridge,973			   void (*cb)(void *data,974				      enum drm_connector_status status),975			   void *data);976void drm_bridge_hpd_disable(struct drm_bridge *bridge);977void drm_bridge_hpd_notify(struct drm_bridge *bridge,978			   enum drm_connector_status status);979 980#ifdef CONFIG_DRM_PANEL_BRIDGE981bool drm_bridge_is_panel(const struct drm_bridge *bridge);982struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);983struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,984					      u32 connector_type);985void drm_panel_bridge_remove(struct drm_bridge *bridge);986int drm_panel_bridge_set_orientation(struct drm_connector *connector,987				     struct drm_bridge *bridge);988struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,989					     struct drm_panel *panel);990struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,991						   struct drm_panel *panel,992						   u32 connector_type);993struct drm_bridge *drmm_panel_bridge_add(struct drm_device *drm,994					     struct drm_panel *panel);995struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);996#else997static inline bool drm_bridge_is_panel(const struct drm_bridge *bridge)998{999	return false;1000}1001 1002static inline int drm_panel_bridge_set_orientation(struct drm_connector *connector,1003						   struct drm_bridge *bridge)1004{1005	return -EINVAL;1006}1007#endif1008 1009#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL_BRIDGE)1010struct drm_bridge *devm_drm_of_get_bridge(struct device *dev, struct device_node *node,1011					  u32 port, u32 endpoint);1012struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm, struct device_node *node,1013					  u32 port, u32 endpoint);1014#else1015static inline struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,1016							struct device_node *node,1017							u32 port,1018							u32 endpoint)1019{1020	return ERR_PTR(-ENODEV);1021}1022 1023static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,1024						     struct device_node *node,1025						     u32 port,1026						     u32 endpoint)1027{1028	return ERR_PTR(-ENODEV);1029}1030#endif1031 1032#endif1033