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v5.4
  1/*
  2 * Copyright (c) 2016 Intel Corporation
  3 *
  4 * Permission to use, copy, modify, distribute, and sell this software and its
  5 * documentation for any purpose is hereby granted without fee, provided that
  6 * the above copyright notice appear in all copies and that both that copyright
  7 * notice and this permission notice appear in supporting documentation, and
  8 * that the name of the copyright holders not be used in advertising or
  9 * publicity pertaining to distribution of the software without specific,
 10 * written prior permission.  The copyright holders make no representations
 11 * about the suitability of this software for any purpose.  It is provided "as
 12 * is" without express or implied warranty.
 13 *
 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 20 * OF THIS SOFTWARE.
 21 */
 22
 23#ifndef __DRM_BRIDGE_H__
 24#define __DRM_BRIDGE_H__
 25
 26#include <linux/list.h>
 27#include <linux/ctype.h>
 
 
 
 
 
 28#include <drm/drm_mode_object.h>
 29#include <drm/drm_modes.h>
 30
 31struct drm_bridge;
 32struct drm_bridge_timings;
 
 
 33struct drm_panel;
 
 
 
 
 
 
 
 
 
 
 
 
 
 34
 35/**
 36 * struct drm_bridge_funcs - drm_bridge control functions
 37 */
 38struct drm_bridge_funcs {
 39	/**
 40	 * @attach:
 41	 *
 42	 * This callback is invoked whenever our bridge is being attached to a
 43	 * &drm_encoder.
 
 44	 *
 45	 * The attach callback is optional.
 46	 *
 47	 * RETURNS:
 48	 *
 49	 * Zero on success, error code on failure.
 50	 */
 51	int (*attach)(struct drm_bridge *bridge);
 
 52
 53	/**
 54	 * @detach:
 55	 *
 56	 * This callback is invoked whenever our bridge is being detached from a
 57	 * &drm_encoder.
 58	 *
 59	 * The detach callback is optional.
 60	 */
 61	void (*detach)(struct drm_bridge *bridge);
 62
 63	/**
 64	 * @mode_valid:
 65	 *
 66	 * This callback is used to check if a specific mode is valid in this
 67	 * bridge. This should be implemented if the bridge has some sort of
 68	 * restriction in the modes it can display. For example, a given bridge
 69	 * may be responsible to set a clock value. If the clock can not
 70	 * produce all the values for the available modes then this callback
 71	 * can be used to restrict the number of modes to only the ones that
 72	 * can be displayed.
 73	 *
 74	 * This hook is used by the probe helpers to filter the mode list in
 75	 * drm_helper_probe_single_connector_modes(), and it is used by the
 76	 * atomic helpers to validate modes supplied by userspace in
 77	 * drm_atomic_helper_check_modeset().
 78	 *
 79	 * This function is optional.
 80	 *
 81	 * NOTE:
 82	 *
 83	 * Since this function is both called from the check phase of an atomic
 84	 * commit, and the mode validation in the probe paths it is not allowed
 85	 * to look at anything else but the passed-in mode, and validate it
 86	 * against configuration-invariant hardward constraints. Any further
 87	 * limits which depend upon the configuration can only be checked in
 88	 * @mode_fixup.
 89	 *
 90	 * RETURNS:
 91	 *
 92	 * drm_mode_status Enum
 93	 */
 94	enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
 
 95					   const struct drm_display_mode *mode);
 96
 97	/**
 98	 * @mode_fixup:
 99	 *
100	 * This callback is used to validate and adjust a mode. The parameter
101	 * mode is the display mode that should be fed to the next element in
102	 * the display chain, either the final &drm_connector or the next
103	 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
104	 * requires. It can be modified by this callback and does not need to
105	 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
106	 *
107	 * This is the only hook that allows a bridge to reject a modeset. If
108	 * this function passes all other callbacks must succeed for this
109	 * configuration.
110	 *
111	 * The mode_fixup callback is optional.
 
 
112	 *
113	 * NOTE:
114	 *
115	 * This function is called in the check phase of atomic modesets, which
116	 * can be aborted for any reason (including on userspace's request to
117	 * just check whether a configuration would be possible). Drivers MUST
118	 * NOT touch any persistent state (hardware or software) or data
119	 * structures except the passed in @state parameter.
120	 *
121	 * Also beware that userspace can request its own custom modes, neither
122	 * core nor helpers filter modes to the list of probe modes reported by
123	 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
124	 * that modes are filtered consistently put any bridge constraints and
125	 * limits checks into @mode_valid.
126	 *
127	 * RETURNS:
128	 *
129	 * True if an acceptable configuration is possible, false if the modeset
130	 * operation should be rejected.
131	 */
132	bool (*mode_fixup)(struct drm_bridge *bridge,
133			   const struct drm_display_mode *mode,
134			   struct drm_display_mode *adjusted_mode);
135	/**
136	 * @disable:
137	 *
138	 * This callback should disable the bridge. It is called right before
139	 * the preceding element in the display pipe is disabled. If the
140	 * preceding element is a bridge this means it's called before that
141	 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
142	 * it's called right before the &drm_encoder_helper_funcs.disable,
143	 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
144	 * hook.
145	 *
146	 * The bridge can assume that the display pipe (i.e. clocks and timing
147	 * signals) feeding it is still running when this callback is called.
148	 *
149	 * The disable callback is optional.
150	 */
151	void (*disable)(struct drm_bridge *bridge);
152
153	/**
154	 * @post_disable:
155	 *
156	 * This callback should disable the bridge. It is called right after the
157	 * preceding element in the display pipe is disabled. If the preceding
158	 * element is a bridge this means it's called after that bridge's
159	 * @post_disable function. If the preceding element is a &drm_encoder
160	 * it's called right after the encoder's
161	 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
162	 * or &drm_encoder_helper_funcs.dpms hook.
163	 *
164	 * The bridge must assume that the display pipe (i.e. clocks and timing
165	 * singals) feeding it is no longer running when this callback is
166	 * called.
167	 *
168	 * The post_disable callback is optional.
169	 */
170	void (*post_disable)(struct drm_bridge *bridge);
171
172	/**
173	 * @mode_set:
174	 *
175	 * This callback should set the given mode on the bridge. It is called
176	 * after the @mode_set callback for the preceding element in the display
177	 * pipeline has been called already. If the bridge is the first element
178	 * then this would be &drm_encoder_helper_funcs.mode_set. The display
179	 * pipe (i.e.  clocks and timing signals) is off when this function is
180	 * called.
181	 *
182	 * The adjusted_mode parameter is the mode output by the CRTC for the
183	 * first bridge in the chain. It can be different from the mode
184	 * parameter that contains the desired mode for the connector at the end
185	 * of the bridges chain, for instance when the first bridge in the chain
186	 * performs scaling. The adjusted mode is mostly useful for the first
187	 * bridge in the chain and is likely irrelevant for the other bridges.
188	 *
189	 * For atomic drivers the adjusted_mode is the mode stored in
190	 * &drm_crtc_state.adjusted_mode.
191	 *
192	 * NOTE:
193	 *
194	 * If a need arises to store and access modes adjusted for other
195	 * locations than the connection between the CRTC and the first bridge,
196	 * the DRM framework will have to be extended with DRM bridge states.
197	 */
198	void (*mode_set)(struct drm_bridge *bridge,
199			 const struct drm_display_mode *mode,
200			 const struct drm_display_mode *adjusted_mode);
201	/**
202	 * @pre_enable:
203	 *
204	 * This callback should enable the bridge. It is called right before
205	 * the preceding element in the display pipe is enabled. If the
206	 * preceding element is a bridge this means it's called before that
207	 * bridge's @pre_enable function. If the preceding element is a
208	 * &drm_encoder it's called right before the encoder's
209	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
210	 * &drm_encoder_helper_funcs.dpms hook.
211	 *
212	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
213	 * will not yet be running when this callback is called. The bridge must
214	 * not enable the display link feeding the next bridge in the chain (if
215	 * there is one) when this callback is called.
216	 *
217	 * The pre_enable callback is optional.
218	 */
219	void (*pre_enable)(struct drm_bridge *bridge);
220
221	/**
222	 * @enable:
223	 *
224	 * This callback should enable the bridge. It is called right after
225	 * the preceding element in the display pipe is enabled. If the
226	 * preceding element is a bridge this means it's called after that
227	 * bridge's @enable function. If the preceding element is a
228	 * &drm_encoder it's called right after the encoder's
229	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
230	 * &drm_encoder_helper_funcs.dpms hook.
231	 *
232	 * The bridge can assume that the display pipe (i.e. clocks and timing
233	 * signals) feeding it is running when this callback is called. This
234	 * callback must enable the display link feeding the next bridge in the
235	 * chain if there is one.
236	 *
237	 * The enable callback is optional.
238	 */
239	void (*enable)(struct drm_bridge *bridge);
240
241	/**
242	 * @atomic_pre_enable:
243	 *
244	 * This callback should enable the bridge. It is called right before
245	 * the preceding element in the display pipe is enabled. If the
246	 * preceding element is a bridge this means it's called before that
247	 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
248	 * element is a &drm_encoder it's called right before the encoder's
249	 * &drm_encoder_helper_funcs.atomic_enable hook.
250	 *
251	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
252	 * will not yet be running when this callback is called. The bridge must
253	 * not enable the display link feeding the next bridge in the chain (if
254	 * there is one) when this callback is called.
255	 *
256	 * Note that this function will only be invoked in the context of an
257	 * atomic commit. It will not be invoked from &drm_bridge_pre_enable. It
258	 * would be prudent to also provide an implementation of @pre_enable if
259	 * you are expecting driver calls into &drm_bridge_pre_enable.
 
260	 *
261	 * The @atomic_pre_enable callback is optional.
262	 */
263	void (*atomic_pre_enable)(struct drm_bridge *bridge,
264				  struct drm_atomic_state *state);
265
266	/**
267	 * @atomic_enable:
268	 *
269	 * This callback should enable the bridge. It is called right after
270	 * the preceding element in the display pipe is enabled. If the
271	 * preceding element is a bridge this means it's called after that
272	 * bridge's @atomic_enable or @enable function. If the preceding element
273	 * is a &drm_encoder it's called right after the encoder's
274	 * &drm_encoder_helper_funcs.atomic_enable hook.
275	 *
276	 * The bridge can assume that the display pipe (i.e. clocks and timing
277	 * signals) feeding it is running when this callback is called. This
278	 * callback must enable the display link feeding the next bridge in the
279	 * chain if there is one.
280	 *
281	 * Note that this function will only be invoked in the context of an
282	 * atomic commit. It will not be invoked from &drm_bridge_enable. It
283	 * would be prudent to also provide an implementation of @enable if
284	 * you are expecting driver calls into &drm_bridge_enable.
285	 *
286	 * The enable callback is optional.
287	 */
288	void (*atomic_enable)(struct drm_bridge *bridge,
289			      struct drm_atomic_state *state);
290	/**
291	 * @atomic_disable:
292	 *
293	 * This callback should disable the bridge. It is called right before
294	 * the preceding element in the display pipe is disabled. If the
295	 * preceding element is a bridge this means it's called before that
296	 * bridge's @atomic_disable or @disable vfunc. If the preceding element
297	 * is a &drm_encoder it's called right before the
298	 * &drm_encoder_helper_funcs.atomic_disable hook.
299	 *
300	 * The bridge can assume that the display pipe (i.e. clocks and timing
301	 * signals) feeding it is still running when this callback is called.
302	 *
303	 * Note that this function will only be invoked in the context of an
304	 * atomic commit. It will not be invoked from &drm_bridge_disable. It
305	 * would be prudent to also provide an implementation of @disable if
306	 * you are expecting driver calls into &drm_bridge_disable.
 
307	 *
308	 * The disable callback is optional.
309	 */
310	void (*atomic_disable)(struct drm_bridge *bridge,
311			       struct drm_atomic_state *state);
312
313	/**
314	 * @atomic_post_disable:
315	 *
316	 * This callback should disable the bridge. It is called right after the
317	 * preceding element in the display pipe is disabled. If the preceding
318	 * element is a bridge this means it's called after that bridge's
319	 * @atomic_post_disable or @post_disable function. If the preceding
320	 * element is a &drm_encoder it's called right after the encoder's
321	 * &drm_encoder_helper_funcs.atomic_disable hook.
322	 *
323	 * The bridge must assume that the display pipe (i.e. clocks and timing
324	 * signals) feeding it is no longer running when this callback is
325	 * called.
326	 *
327	 * Note that this function will only be invoked in the context of an
328	 * atomic commit. It will not be invoked from &drm_bridge_post_disable.
 
329	 * It would be prudent to also provide an implementation of
330	 * @post_disable if you are expecting driver calls into
331	 * &drm_bridge_post_disable.
332	 *
333	 * The post_disable callback is optional.
334	 */
335	void (*atomic_post_disable)(struct drm_bridge *bridge,
336				    struct drm_atomic_state *state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
337};
338
339/**
340 * struct drm_bridge_timings - timing information for the bridge
341 */
342struct drm_bridge_timings {
343	/**
344	 * @input_bus_flags:
345	 *
346	 * Tells what additional settings for the pixel data on the bus
347	 * this bridge requires (like pixel signal polarity). See also
348	 * &drm_display_info->bus_flags.
349	 */
350	u32 input_bus_flags;
351	/**
352	 * @setup_time_ps:
353	 *
354	 * Defines the time in picoseconds the input data lines must be
355	 * stable before the clock edge.
356	 */
357	u32 setup_time_ps;
358	/**
359	 * @hold_time_ps:
360	 *
361	 * Defines the time in picoseconds taken for the bridge to sample the
362	 * input signal after the clock edge.
363	 */
364	u32 hold_time_ps;
365	/**
366	 * @dual_link:
367	 *
368	 * True if the bus operates in dual-link mode. The exact meaning is
369	 * dependent on the bus type. For LVDS buses, this indicates that even-
370	 * and odd-numbered pixels are received on separate links.
371	 */
372	bool dual_link;
373};
374
375/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
376 * struct drm_bridge - central DRM bridge control structure
377 */
378struct drm_bridge {
 
 
379	/** @dev: DRM device this bridge belongs to */
380	struct drm_device *dev;
381	/** @encoder: encoder to which this bridge is connected */
382	struct drm_encoder *encoder;
383	/** @next: the next bridge in the encoder chain */
384	struct drm_bridge *next;
385#ifdef CONFIG_OF
386	/** @of_node: device node pointer to the bridge */
387	struct device_node *of_node;
388#endif
389	/** @list: to keep track of all added bridges */
390	struct list_head list;
391	/**
392	 * @timings:
393	 *
394	 * the timing specification for the bridge, if any (may be NULL)
395	 */
396	const struct drm_bridge_timings *timings;
397	/** @funcs: control functions */
398	const struct drm_bridge_funcs *funcs;
399	/** @driver_private: pointer to the bridge driver's internal context */
400	void *driver_private;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
401};
402
 
 
 
 
 
 
403void drm_bridge_add(struct drm_bridge *bridge);
404void drm_bridge_remove(struct drm_bridge *bridge);
405struct drm_bridge *of_drm_find_bridge(struct device_node *np);
406int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
407		      struct drm_bridge *previous);
 
408
409bool drm_bridge_mode_fixup(struct drm_bridge *bridge,
410			   const struct drm_display_mode *mode,
411			   struct drm_display_mode *adjusted_mode);
412enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge,
413					   const struct drm_display_mode *mode);
414void drm_bridge_disable(struct drm_bridge *bridge);
415void drm_bridge_post_disable(struct drm_bridge *bridge);
416void drm_bridge_mode_set(struct drm_bridge *bridge,
417			 const struct drm_display_mode *mode,
418			 const struct drm_display_mode *adjusted_mode);
419void drm_bridge_pre_enable(struct drm_bridge *bridge);
420void drm_bridge_enable(struct drm_bridge *bridge);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
421
422void drm_atomic_bridge_disable(struct drm_bridge *bridge,
423			       struct drm_atomic_state *state);
424void drm_atomic_bridge_post_disable(struct drm_bridge *bridge,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
425				    struct drm_atomic_state *state);
426void drm_atomic_bridge_pre_enable(struct drm_bridge *bridge,
427				  struct drm_atomic_state *state);
428void drm_atomic_bridge_enable(struct drm_bridge *bridge,
429			      struct drm_atomic_state *state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
430
431#ifdef CONFIG_DRM_PANEL_BRIDGE
432struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
433					u32 connector_type);
 
434void drm_panel_bridge_remove(struct drm_bridge *bridge);
435struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
436					     struct drm_panel *panel,
437					     u32 connector_type);
 
 
 
438#endif
439
440#endif
v5.14.15
  1/*
  2 * Copyright (c) 2016 Intel Corporation
  3 *
  4 * Permission to use, copy, modify, distribute, and sell this software and its
  5 * documentation for any purpose is hereby granted without fee, provided that
  6 * the above copyright notice appear in all copies and that both that copyright
  7 * notice and this permission notice appear in supporting documentation, and
  8 * that the name of the copyright holders not be used in advertising or
  9 * publicity pertaining to distribution of the software without specific,
 10 * written prior permission.  The copyright holders make no representations
 11 * about the suitability of this software for any purpose.  It is provided "as
 12 * is" without express or implied warranty.
 13 *
 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 20 * OF THIS SOFTWARE.
 21 */
 22
 23#ifndef __DRM_BRIDGE_H__
 24#define __DRM_BRIDGE_H__
 25
 
 26#include <linux/ctype.h>
 27#include <linux/list.h>
 28#include <linux/mutex.h>
 29
 30#include <drm/drm_atomic.h>
 31#include <drm/drm_encoder.h>
 32#include <drm/drm_mode_object.h>
 33#include <drm/drm_modes.h>
 34
 35struct drm_bridge;
 36struct drm_bridge_timings;
 37struct drm_connector;
 38struct drm_display_info;
 39struct drm_panel;
 40struct edid;
 41struct i2c_adapter;
 42
 43/**
 44 * enum drm_bridge_attach_flags - Flags for &drm_bridge_funcs.attach
 45 */
 46enum drm_bridge_attach_flags {
 47	/**
 48	 * @DRM_BRIDGE_ATTACH_NO_CONNECTOR: When this flag is set the bridge
 49	 * shall not create a drm_connector.
 50	 */
 51	DRM_BRIDGE_ATTACH_NO_CONNECTOR = BIT(0),
 52};
 53
 54/**
 55 * struct drm_bridge_funcs - drm_bridge control functions
 56 */
 57struct drm_bridge_funcs {
 58	/**
 59	 * @attach:
 60	 *
 61	 * This callback is invoked whenever our bridge is being attached to a
 62	 * &drm_encoder. The flags argument tunes the behaviour of the attach
 63	 * operation (see DRM_BRIDGE_ATTACH_*).
 64	 *
 65	 * The @attach callback is optional.
 66	 *
 67	 * RETURNS:
 68	 *
 69	 * Zero on success, error code on failure.
 70	 */
 71	int (*attach)(struct drm_bridge *bridge,
 72		      enum drm_bridge_attach_flags flags);
 73
 74	/**
 75	 * @detach:
 76	 *
 77	 * This callback is invoked whenever our bridge is being detached from a
 78	 * &drm_encoder.
 79	 *
 80	 * The @detach callback is optional.
 81	 */
 82	void (*detach)(struct drm_bridge *bridge);
 83
 84	/**
 85	 * @mode_valid:
 86	 *
 87	 * This callback is used to check if a specific mode is valid in this
 88	 * bridge. This should be implemented if the bridge has some sort of
 89	 * restriction in the modes it can display. For example, a given bridge
 90	 * may be responsible to set a clock value. If the clock can not
 91	 * produce all the values for the available modes then this callback
 92	 * can be used to restrict the number of modes to only the ones that
 93	 * can be displayed.
 94	 *
 95	 * This hook is used by the probe helpers to filter the mode list in
 96	 * drm_helper_probe_single_connector_modes(), and it is used by the
 97	 * atomic helpers to validate modes supplied by userspace in
 98	 * drm_atomic_helper_check_modeset().
 99	 *
100	 * The @mode_valid callback is optional.
101	 *
102	 * NOTE:
103	 *
104	 * Since this function is both called from the check phase of an atomic
105	 * commit, and the mode validation in the probe paths it is not allowed
106	 * to look at anything else but the passed-in mode, and validate it
107	 * against configuration-invariant hardward constraints. Any further
108	 * limits which depend upon the configuration can only be checked in
109	 * @mode_fixup.
110	 *
111	 * RETURNS:
112	 *
113	 * drm_mode_status Enum
114	 */
115	enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
116					   const struct drm_display_info *info,
117					   const struct drm_display_mode *mode);
118
119	/**
120	 * @mode_fixup:
121	 *
122	 * This callback is used to validate and adjust a mode. The parameter
123	 * mode is the display mode that should be fed to the next element in
124	 * the display chain, either the final &drm_connector or the next
125	 * &drm_bridge. The parameter adjusted_mode is the input mode the bridge
126	 * requires. It can be modified by this callback and does not need to
127	 * match mode. See also &drm_crtc_state.adjusted_mode for more details.
128	 *
129	 * This is the only hook that allows a bridge to reject a modeset. If
130	 * this function passes all other callbacks must succeed for this
131	 * configuration.
132	 *
133	 * The mode_fixup callback is optional. &drm_bridge_funcs.mode_fixup()
134	 * is not called when &drm_bridge_funcs.atomic_check() is implemented,
135	 * so only one of them should be provided.
136	 *
137	 * NOTE:
138	 *
139	 * This function is called in the check phase of atomic modesets, which
140	 * can be aborted for any reason (including on userspace's request to
141	 * just check whether a configuration would be possible). Drivers MUST
142	 * NOT touch any persistent state (hardware or software) or data
143	 * structures except the passed in @state parameter.
144	 *
145	 * Also beware that userspace can request its own custom modes, neither
146	 * core nor helpers filter modes to the list of probe modes reported by
147	 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
148	 * that modes are filtered consistently put any bridge constraints and
149	 * limits checks into @mode_valid.
150	 *
151	 * RETURNS:
152	 *
153	 * True if an acceptable configuration is possible, false if the modeset
154	 * operation should be rejected.
155	 */
156	bool (*mode_fixup)(struct drm_bridge *bridge,
157			   const struct drm_display_mode *mode,
158			   struct drm_display_mode *adjusted_mode);
159	/**
160	 * @disable:
161	 *
162	 * This callback should disable the bridge. It is called right before
163	 * the preceding element in the display pipe is disabled. If the
164	 * preceding element is a bridge this means it's called before that
165	 * bridge's @disable vfunc. If the preceding element is a &drm_encoder
166	 * it's called right before the &drm_encoder_helper_funcs.disable,
167	 * &drm_encoder_helper_funcs.prepare or &drm_encoder_helper_funcs.dpms
168	 * hook.
169	 *
170	 * The bridge can assume that the display pipe (i.e. clocks and timing
171	 * signals) feeding it is still running when this callback is called.
172	 *
173	 * The @disable callback is optional.
174	 */
175	void (*disable)(struct drm_bridge *bridge);
176
177	/**
178	 * @post_disable:
179	 *
180	 * This callback should disable the bridge. It is called right after the
181	 * preceding element in the display pipe is disabled. If the preceding
182	 * element is a bridge this means it's called after that bridge's
183	 * @post_disable function. If the preceding element is a &drm_encoder
184	 * it's called right after the encoder's
185	 * &drm_encoder_helper_funcs.disable, &drm_encoder_helper_funcs.prepare
186	 * or &drm_encoder_helper_funcs.dpms hook.
187	 *
188	 * The bridge must assume that the display pipe (i.e. clocks and timing
189	 * singals) feeding it is no longer running when this callback is
190	 * called.
191	 *
192	 * The @post_disable callback is optional.
193	 */
194	void (*post_disable)(struct drm_bridge *bridge);
195
196	/**
197	 * @mode_set:
198	 *
199	 * This callback should set the given mode on the bridge. It is called
200	 * after the @mode_set callback for the preceding element in the display
201	 * pipeline has been called already. If the bridge is the first element
202	 * then this would be &drm_encoder_helper_funcs.mode_set. The display
203	 * pipe (i.e.  clocks and timing signals) is off when this function is
204	 * called.
205	 *
206	 * The adjusted_mode parameter is the mode output by the CRTC for the
207	 * first bridge in the chain. It can be different from the mode
208	 * parameter that contains the desired mode for the connector at the end
209	 * of the bridges chain, for instance when the first bridge in the chain
210	 * performs scaling. The adjusted mode is mostly useful for the first
211	 * bridge in the chain and is likely irrelevant for the other bridges.
212	 *
213	 * For atomic drivers the adjusted_mode is the mode stored in
214	 * &drm_crtc_state.adjusted_mode.
215	 *
216	 * NOTE:
217	 *
218	 * If a need arises to store and access modes adjusted for other
219	 * locations than the connection between the CRTC and the first bridge,
220	 * the DRM framework will have to be extended with DRM bridge states.
221	 */
222	void (*mode_set)(struct drm_bridge *bridge,
223			 const struct drm_display_mode *mode,
224			 const struct drm_display_mode *adjusted_mode);
225	/**
226	 * @pre_enable:
227	 *
228	 * This callback should enable the bridge. It is called right before
229	 * the preceding element in the display pipe is enabled. If the
230	 * preceding element is a bridge this means it's called before that
231	 * bridge's @pre_enable function. If the preceding element is a
232	 * &drm_encoder it's called right before the encoder's
233	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
234	 * &drm_encoder_helper_funcs.dpms hook.
235	 *
236	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
237	 * will not yet be running when this callback is called. The bridge must
238	 * not enable the display link feeding the next bridge in the chain (if
239	 * there is one) when this callback is called.
240	 *
241	 * The @pre_enable callback is optional.
242	 */
243	void (*pre_enable)(struct drm_bridge *bridge);
244
245	/**
246	 * @enable:
247	 *
248	 * This callback should enable the bridge. It is called right after
249	 * the preceding element in the display pipe is enabled. If the
250	 * preceding element is a bridge this means it's called after that
251	 * bridge's @enable function. If the preceding element is a
252	 * &drm_encoder it's called right after the encoder's
253	 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
254	 * &drm_encoder_helper_funcs.dpms hook.
255	 *
256	 * The bridge can assume that the display pipe (i.e. clocks and timing
257	 * signals) feeding it is running when this callback is called. This
258	 * callback must enable the display link feeding the next bridge in the
259	 * chain if there is one.
260	 *
261	 * The @enable callback is optional.
262	 */
263	void (*enable)(struct drm_bridge *bridge);
264
265	/**
266	 * @atomic_pre_enable:
267	 *
268	 * This callback should enable the bridge. It is called right before
269	 * the preceding element in the display pipe is enabled. If the
270	 * preceding element is a bridge this means it's called before that
271	 * bridge's @atomic_pre_enable or @pre_enable function. If the preceding
272	 * element is a &drm_encoder it's called right before the encoder's
273	 * &drm_encoder_helper_funcs.atomic_enable hook.
274	 *
275	 * The display pipe (i.e. clocks and timing signals) feeding this bridge
276	 * will not yet be running when this callback is called. The bridge must
277	 * not enable the display link feeding the next bridge in the chain (if
278	 * there is one) when this callback is called.
279	 *
280	 * Note that this function will only be invoked in the context of an
281	 * atomic commit. It will not be invoked from
282	 * &drm_bridge_chain_pre_enable. It would be prudent to also provide an
283	 * implementation of @pre_enable if you are expecting driver calls into
284	 * &drm_bridge_chain_pre_enable.
285	 *
286	 * The @atomic_pre_enable callback is optional.
287	 */
288	void (*atomic_pre_enable)(struct drm_bridge *bridge,
289				  struct drm_bridge_state *old_bridge_state);
290
291	/**
292	 * @atomic_enable:
293	 *
294	 * This callback should enable the bridge. It is called right after
295	 * the preceding element in the display pipe is enabled. If the
296	 * preceding element is a bridge this means it's called after that
297	 * bridge's @atomic_enable or @enable function. If the preceding element
298	 * is a &drm_encoder it's called right after the encoder's
299	 * &drm_encoder_helper_funcs.atomic_enable hook.
300	 *
301	 * The bridge can assume that the display pipe (i.e. clocks and timing
302	 * signals) feeding it is running when this callback is called. This
303	 * callback must enable the display link feeding the next bridge in the
304	 * chain if there is one.
305	 *
306	 * Note that this function will only be invoked in the context of an
307	 * atomic commit. It will not be invoked from &drm_bridge_chain_enable.
308	 * It would be prudent to also provide an implementation of @enable if
309	 * you are expecting driver calls into &drm_bridge_chain_enable.
310	 *
311	 * The @atomic_enable callback is optional.
312	 */
313	void (*atomic_enable)(struct drm_bridge *bridge,
314			      struct drm_bridge_state *old_bridge_state);
315	/**
316	 * @atomic_disable:
317	 *
318	 * This callback should disable the bridge. It is called right before
319	 * the preceding element in the display pipe is disabled. If the
320	 * preceding element is a bridge this means it's called before that
321	 * bridge's @atomic_disable or @disable vfunc. If the preceding element
322	 * is a &drm_encoder it's called right before the
323	 * &drm_encoder_helper_funcs.atomic_disable hook.
324	 *
325	 * The bridge can assume that the display pipe (i.e. clocks and timing
326	 * signals) feeding it is still running when this callback is called.
327	 *
328	 * Note that this function will only be invoked in the context of an
329	 * atomic commit. It will not be invoked from
330	 * &drm_bridge_chain_disable. It would be prudent to also provide an
331	 * implementation of @disable if you are expecting driver calls into
332	 * &drm_bridge_chain_disable.
333	 *
334	 * The @atomic_disable callback is optional.
335	 */
336	void (*atomic_disable)(struct drm_bridge *bridge,
337			       struct drm_bridge_state *old_bridge_state);
338
339	/**
340	 * @atomic_post_disable:
341	 *
342	 * This callback should disable the bridge. It is called right after the
343	 * preceding element in the display pipe is disabled. If the preceding
344	 * element is a bridge this means it's called after that bridge's
345	 * @atomic_post_disable or @post_disable function. If the preceding
346	 * element is a &drm_encoder it's called right after the encoder's
347	 * &drm_encoder_helper_funcs.atomic_disable hook.
348	 *
349	 * The bridge must assume that the display pipe (i.e. clocks and timing
350	 * signals) feeding it is no longer running when this callback is
351	 * called.
352	 *
353	 * Note that this function will only be invoked in the context of an
354	 * atomic commit. It will not be invoked from
355	 * &drm_bridge_chain_post_disable.
356	 * It would be prudent to also provide an implementation of
357	 * @post_disable if you are expecting driver calls into
358	 * &drm_bridge_chain_post_disable.
359	 *
360	 * The @atomic_post_disable callback is optional.
361	 */
362	void (*atomic_post_disable)(struct drm_bridge *bridge,
363				    struct drm_bridge_state *old_bridge_state);
364
365	/**
366	 * @atomic_duplicate_state:
367	 *
368	 * Duplicate the current bridge state object (which is guaranteed to be
369	 * non-NULL).
370	 *
371	 * The atomic_duplicate_state hook is mandatory if the bridge
372	 * implements any of the atomic hooks, and should be left unassigned
373	 * otherwise. For bridges that don't subclass &drm_bridge_state, the
374	 * drm_atomic_helper_bridge_duplicate_state() helper function shall be
375	 * used to implement this hook.
376	 *
377	 * RETURNS:
378	 * A valid drm_bridge_state object or NULL if the allocation fails.
379	 */
380	struct drm_bridge_state *(*atomic_duplicate_state)(struct drm_bridge *bridge);
381
382	/**
383	 * @atomic_destroy_state:
384	 *
385	 * Destroy a bridge state object previously allocated by
386	 * &drm_bridge_funcs.atomic_duplicate_state().
387	 *
388	 * The atomic_destroy_state hook is mandatory if the bridge implements
389	 * any of the atomic hooks, and should be left unassigned otherwise.
390	 * For bridges that don't subclass &drm_bridge_state, the
391	 * drm_atomic_helper_bridge_destroy_state() helper function shall be
392	 * used to implement this hook.
393	 */
394	void (*atomic_destroy_state)(struct drm_bridge *bridge,
395				     struct drm_bridge_state *state);
396
397	/**
398	 * @atomic_get_output_bus_fmts:
399	 *
400	 * Return the supported bus formats on the output end of a bridge.
401	 * The returned array must be allocated with kmalloc() and will be
402	 * freed by the caller. If the allocation fails, NULL should be
403	 * returned. num_output_fmts must be set to the returned array size.
404	 * Formats listed in the returned array should be listed in decreasing
405	 * preference order (the core will try all formats until it finds one
406	 * that works).
407	 *
408	 * This method is only called on the last element of the bridge chain
409	 * as part of the bus format negotiation process that happens in
410	 * &drm_atomic_bridge_chain_select_bus_fmts().
411	 * This method is optional. When not implemented, the core will
412	 * fall back to &drm_connector.display_info.bus_formats[0] if
413	 * &drm_connector.display_info.num_bus_formats > 0,
414	 * or to MEDIA_BUS_FMT_FIXED otherwise.
415	 */
416	u32 *(*atomic_get_output_bus_fmts)(struct drm_bridge *bridge,
417					   struct drm_bridge_state *bridge_state,
418					   struct drm_crtc_state *crtc_state,
419					   struct drm_connector_state *conn_state,
420					   unsigned int *num_output_fmts);
421
422	/**
423	 * @atomic_get_input_bus_fmts:
424	 *
425	 * Return the supported bus formats on the input end of a bridge for
426	 * a specific output bus format.
427	 *
428	 * The returned array must be allocated with kmalloc() and will be
429	 * freed by the caller. If the allocation fails, NULL should be
430	 * returned. num_output_fmts must be set to the returned array size.
431	 * Formats listed in the returned array should be listed in decreasing
432	 * preference order (the core will try all formats until it finds one
433	 * that works). When the format is not supported NULL should be
434	 * returned and num_output_fmts should be set to 0.
435	 *
436	 * This method is called on all elements of the bridge chain as part of
437	 * the bus format negotiation process that happens in
438	 * drm_atomic_bridge_chain_select_bus_fmts().
439	 * This method is optional. When not implemented, the core will bypass
440	 * bus format negotiation on this element of the bridge without
441	 * failing, and the previous element in the chain will be passed
442	 * MEDIA_BUS_FMT_FIXED as its output bus format.
443	 *
444	 * Bridge drivers that need to support being linked to bridges that are
445	 * not supporting bus format negotiation should handle the
446	 * output_fmt == MEDIA_BUS_FMT_FIXED case appropriately, by selecting a
447	 * sensible default value or extracting this information from somewhere
448	 * else (FW property, &drm_display_mode, &drm_display_info, ...)
449	 *
450	 * Note: Even if input format selection on the first bridge has no
451	 * impact on the negotiation process (bus format negotiation stops once
452	 * we reach the first element of the chain), drivers are expected to
453	 * return accurate input formats as the input format may be used to
454	 * configure the CRTC output appropriately.
455	 */
456	u32 *(*atomic_get_input_bus_fmts)(struct drm_bridge *bridge,
457					  struct drm_bridge_state *bridge_state,
458					  struct drm_crtc_state *crtc_state,
459					  struct drm_connector_state *conn_state,
460					  u32 output_fmt,
461					  unsigned int *num_input_fmts);
462
463	/**
464	 * @atomic_check:
465	 *
466	 * This method is responsible for checking bridge state correctness.
467	 * It can also check the state of the surrounding components in chain
468	 * to make sure the whole pipeline can work properly.
469	 *
470	 * &drm_bridge_funcs.atomic_check() hooks are called in reverse
471	 * order (from the last to the first bridge).
472	 *
473	 * This method is optional. &drm_bridge_funcs.mode_fixup() is not
474	 * called when &drm_bridge_funcs.atomic_check() is implemented, so only
475	 * one of them should be provided.
476	 *
477	 * If drivers need to tweak &drm_bridge_state.input_bus_cfg.flags or
478	 * &drm_bridge_state.output_bus_cfg.flags it should happen in
479	 * this function. By default the &drm_bridge_state.output_bus_cfg.flags
480	 * field is set to the next bridge
481	 * &drm_bridge_state.input_bus_cfg.flags value or
482	 * &drm_connector.display_info.bus_flags if the bridge is the last
483	 * element in the chain.
484	 *
485	 * RETURNS:
486	 * zero if the check passed, a negative error code otherwise.
487	 */
488	int (*atomic_check)(struct drm_bridge *bridge,
489			    struct drm_bridge_state *bridge_state,
490			    struct drm_crtc_state *crtc_state,
491			    struct drm_connector_state *conn_state);
492
493	/**
494	 * @atomic_reset:
495	 *
496	 * Reset the bridge to a predefined state (or retrieve its current
497	 * state) and return a &drm_bridge_state object matching this state.
498	 * This function is called at attach time.
499	 *
500	 * The atomic_reset hook is mandatory if the bridge implements any of
501	 * the atomic hooks, and should be left unassigned otherwise. For
502	 * bridges that don't subclass &drm_bridge_state, the
503	 * drm_atomic_helper_bridge_reset() helper function shall be used to
504	 * implement this hook.
505	 *
506	 * Note that the atomic_reset() semantics is not exactly matching the
507	 * reset() semantics found on other components (connector, plane, ...).
508	 *
509	 * 1. The reset operation happens when the bridge is attached, not when
510	 *    drm_mode_config_reset() is called
511	 * 2. It's meant to be used exclusively on bridges that have been
512	 *    converted to the ATOMIC API
513	 *
514	 * RETURNS:
515	 * A valid drm_bridge_state object in case of success, an ERR_PTR()
516	 * giving the reason of the failure otherwise.
517	 */
518	struct drm_bridge_state *(*atomic_reset)(struct drm_bridge *bridge);
519
520	/**
521	 * @detect:
522	 *
523	 * Check if anything is attached to the bridge output.
524	 *
525	 * This callback is optional, if not implemented the bridge will be
526	 * considered as always having a component attached to its output.
527	 * Bridges that implement this callback shall set the
528	 * DRM_BRIDGE_OP_DETECT flag in their &drm_bridge->ops.
529	 *
530	 * RETURNS:
531	 *
532	 * drm_connector_status indicating the bridge output status.
533	 */
534	enum drm_connector_status (*detect)(struct drm_bridge *bridge);
535
536	/**
537	 * @get_modes:
538	 *
539	 * Fill all modes currently valid for the sink into the &drm_connector
540	 * with drm_mode_probed_add().
541	 *
542	 * The @get_modes callback is mostly intended to support non-probeable
543	 * displays such as many fixed panels. Bridges that support reading
544	 * EDID shall leave @get_modes unimplemented and implement the
545	 * &drm_bridge_funcs->get_edid callback instead.
546	 *
547	 * This callback is optional. Bridges that implement it shall set the
548	 * DRM_BRIDGE_OP_MODES flag in their &drm_bridge->ops.
549	 *
550	 * The connector parameter shall be used for the sole purpose of
551	 * filling modes, and shall not be stored internally by bridge drivers
552	 * for future usage.
553	 *
554	 * RETURNS:
555	 *
556	 * The number of modes added by calling drm_mode_probed_add().
557	 */
558	int (*get_modes)(struct drm_bridge *bridge,
559			 struct drm_connector *connector);
560
561	/**
562	 * @get_edid:
563	 *
564	 * Read and parse the EDID data of the connected display.
565	 *
566	 * The @get_edid callback is the preferred way of reporting mode
567	 * information for a display connected to the bridge output. Bridges
568	 * that support reading EDID shall implement this callback and leave
569	 * the @get_modes callback unimplemented.
570	 *
571	 * The caller of this operation shall first verify the output
572	 * connection status and refrain from reading EDID from a disconnected
573	 * output.
574	 *
575	 * This callback is optional. Bridges that implement it shall set the
576	 * DRM_BRIDGE_OP_EDID flag in their &drm_bridge->ops.
577	 *
578	 * The connector parameter shall be used for the sole purpose of EDID
579	 * retrieval and parsing, and shall not be stored internally by bridge
580	 * drivers for future usage.
581	 *
582	 * RETURNS:
583	 *
584	 * An edid structure newly allocated with kmalloc() (or similar) on
585	 * success, or NULL otherwise. The caller is responsible for freeing
586	 * the returned edid structure with kfree().
587	 */
588	struct edid *(*get_edid)(struct drm_bridge *bridge,
589				 struct drm_connector *connector);
590
591	/**
592	 * @hpd_notify:
593	 *
594	 * Notify the bridge of hot plug detection.
595	 *
596	 * This callback is optional, it may be implemented by bridges that
597	 * need to be notified of display connection or disconnection for
598	 * internal reasons. One use case is to reset the internal state of CEC
599	 * controllers for HDMI bridges.
600	 */
601	void (*hpd_notify)(struct drm_bridge *bridge,
602			   enum drm_connector_status status);
603
604	/**
605	 * @hpd_enable:
606	 *
607	 * Enable hot plug detection. From now on the bridge shall call
608	 * drm_bridge_hpd_notify() each time a change is detected in the output
609	 * connection status, until hot plug detection gets disabled with
610	 * @hpd_disable.
611	 *
612	 * This callback is optional and shall only be implemented by bridges
613	 * that support hot-plug notification without polling. Bridges that
614	 * implement it shall also implement the @hpd_disable callback and set
615	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
616	 */
617	void (*hpd_enable)(struct drm_bridge *bridge);
618
619	/**
620	 * @hpd_disable:
621	 *
622	 * Disable hot plug detection. Once this function returns the bridge
623	 * shall not call drm_bridge_hpd_notify() when a change in the output
624	 * connection status occurs.
625	 *
626	 * This callback is optional and shall only be implemented by bridges
627	 * that support hot-plug notification without polling. Bridges that
628	 * implement it shall also implement the @hpd_enable callback and set
629	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
630	 */
631	void (*hpd_disable)(struct drm_bridge *bridge);
632};
633
634/**
635 * struct drm_bridge_timings - timing information for the bridge
636 */
637struct drm_bridge_timings {
638	/**
639	 * @input_bus_flags:
640	 *
641	 * Tells what additional settings for the pixel data on the bus
642	 * this bridge requires (like pixel signal polarity). See also
643	 * &drm_display_info->bus_flags.
644	 */
645	u32 input_bus_flags;
646	/**
647	 * @setup_time_ps:
648	 *
649	 * Defines the time in picoseconds the input data lines must be
650	 * stable before the clock edge.
651	 */
652	u32 setup_time_ps;
653	/**
654	 * @hold_time_ps:
655	 *
656	 * Defines the time in picoseconds taken for the bridge to sample the
657	 * input signal after the clock edge.
658	 */
659	u32 hold_time_ps;
660	/**
661	 * @dual_link:
662	 *
663	 * True if the bus operates in dual-link mode. The exact meaning is
664	 * dependent on the bus type. For LVDS buses, this indicates that even-
665	 * and odd-numbered pixels are received on separate links.
666	 */
667	bool dual_link;
668};
669
670/**
671 * enum drm_bridge_ops - Bitmask of operations supported by the bridge
672 */
673enum drm_bridge_ops {
674	/**
675	 * @DRM_BRIDGE_OP_DETECT: The bridge can detect displays connected to
676	 * its output. Bridges that set this flag shall implement the
677	 * &drm_bridge_funcs->detect callback.
678	 */
679	DRM_BRIDGE_OP_DETECT = BIT(0),
680	/**
681	 * @DRM_BRIDGE_OP_EDID: The bridge can retrieve the EDID of the display
682	 * connected to its output. Bridges that set this flag shall implement
683	 * the &drm_bridge_funcs->get_edid callback.
684	 */
685	DRM_BRIDGE_OP_EDID = BIT(1),
686	/**
687	 * @DRM_BRIDGE_OP_HPD: The bridge can detect hot-plug and hot-unplug
688	 * without requiring polling. Bridges that set this flag shall
689	 * implement the &drm_bridge_funcs->hpd_enable and
690	 * &drm_bridge_funcs->hpd_disable callbacks if they support enabling
691	 * and disabling hot-plug detection dynamically.
692	 */
693	DRM_BRIDGE_OP_HPD = BIT(2),
694	/**
695	 * @DRM_BRIDGE_OP_MODES: The bridge can retrieve the modes supported
696	 * by the display at its output. This does not include reading EDID
697	 * which is separately covered by @DRM_BRIDGE_OP_EDID. Bridges that set
698	 * this flag shall implement the &drm_bridge_funcs->get_modes callback.
699	 */
700	DRM_BRIDGE_OP_MODES = BIT(3),
701};
702
703/**
704 * struct drm_bridge - central DRM bridge control structure
705 */
706struct drm_bridge {
707	/** @base: inherit from &drm_private_object */
708	struct drm_private_obj base;
709	/** @dev: DRM device this bridge belongs to */
710	struct drm_device *dev;
711	/** @encoder: encoder to which this bridge is connected */
712	struct drm_encoder *encoder;
713	/** @chain_node: used to form a bridge chain */
714	struct list_head chain_node;
715#ifdef CONFIG_OF
716	/** @of_node: device node pointer to the bridge */
717	struct device_node *of_node;
718#endif
719	/** @list: to keep track of all added bridges */
720	struct list_head list;
721	/**
722	 * @timings:
723	 *
724	 * the timing specification for the bridge, if any (may be NULL)
725	 */
726	const struct drm_bridge_timings *timings;
727	/** @funcs: control functions */
728	const struct drm_bridge_funcs *funcs;
729	/** @driver_private: pointer to the bridge driver's internal context */
730	void *driver_private;
731	/** @ops: bitmask of operations supported by the bridge */
732	enum drm_bridge_ops ops;
733	/**
734	 * @type: Type of the connection at the bridge output
735	 * (DRM_MODE_CONNECTOR_*). For bridges at the end of this chain this
736	 * identifies the type of connected display.
737	 */
738	int type;
739	/**
740	 * @interlace_allowed: Indicate that the bridge can handle interlaced
741	 * modes.
742	 */
743	bool interlace_allowed;
744	/**
745	 * @ddc: Associated I2C adapter for DDC access, if any.
746	 */
747	struct i2c_adapter *ddc;
748	/** private: */
749	/**
750	 * @hpd_mutex: Protects the @hpd_cb and @hpd_data fields.
751	 */
752	struct mutex hpd_mutex;
753	/**
754	 * @hpd_cb: Hot plug detection callback, registered with
755	 * drm_bridge_hpd_enable().
756	 */
757	void (*hpd_cb)(void *data, enum drm_connector_status status);
758	/**
759	 * @hpd_data: Private data passed to the Hot plug detection callback
760	 * @hpd_cb.
761	 */
762	void *hpd_data;
763};
764
765static inline struct drm_bridge *
766drm_priv_to_bridge(struct drm_private_obj *priv)
767{
768	return container_of(priv, struct drm_bridge, base);
769}
770
771void drm_bridge_add(struct drm_bridge *bridge);
772void drm_bridge_remove(struct drm_bridge *bridge);
773struct drm_bridge *of_drm_find_bridge(struct device_node *np);
774int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
775		      struct drm_bridge *previous,
776		      enum drm_bridge_attach_flags flags);
777
778/**
779 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
780 * @bridge: bridge object
781 *
782 * RETURNS:
783 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
784 */
785static inline struct drm_bridge *
786drm_bridge_get_next_bridge(struct drm_bridge *bridge)
787{
788	if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))
789		return NULL;
790
791	return list_next_entry(bridge, chain_node);
792}
793
794/**
795 * drm_bridge_get_prev_bridge() - Get the previous bridge in the chain
796 * @bridge: bridge object
797 *
798 * RETURNS:
799 * the previous bridge in the chain, or NULL if @bridge is the first.
800 */
801static inline struct drm_bridge *
802drm_bridge_get_prev_bridge(struct drm_bridge *bridge)
803{
804	if (list_is_first(&bridge->chain_node, &bridge->encoder->bridge_chain))
805		return NULL;
806
807	return list_prev_entry(bridge, chain_node);
808}
809
810/**
811 * drm_bridge_chain_get_first_bridge() - Get the first bridge in the chain
812 * @encoder: encoder object
813 *
814 * RETURNS:
815 * the first bridge in the chain, or NULL if @encoder has no bridge attached
816 * to it.
817 */
818static inline struct drm_bridge *
819drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)
820{
821	return list_first_entry_or_null(&encoder->bridge_chain,
822					struct drm_bridge, chain_node);
823}
824
825/**
826 * drm_for_each_bridge_in_chain() - Iterate over all bridges present in a chain
827 * @encoder: the encoder to iterate bridges on
828 * @bridge: a bridge pointer updated to point to the current bridge at each
829 *	    iteration
830 *
831 * Iterate over all bridges present in the bridge chain attached to @encoder.
832 */
833#define drm_for_each_bridge_in_chain(encoder, bridge)			\
834	list_for_each_entry(bridge, &(encoder)->bridge_chain, chain_node)
835
836bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
837				 const struct drm_display_mode *mode,
838				 struct drm_display_mode *adjusted_mode);
839enum drm_mode_status
840drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
841			    const struct drm_display_info *info,
842			    const struct drm_display_mode *mode);
843void drm_bridge_chain_disable(struct drm_bridge *bridge);
844void drm_bridge_chain_post_disable(struct drm_bridge *bridge);
845void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
846			       const struct drm_display_mode *mode,
847			       const struct drm_display_mode *adjusted_mode);
848void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
849void drm_bridge_chain_enable(struct drm_bridge *bridge);
850
851int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
852				  struct drm_crtc_state *crtc_state,
853				  struct drm_connector_state *conn_state);
854void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
855				     struct drm_atomic_state *state);
856void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
857					  struct drm_atomic_state *state);
858void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
859					struct drm_atomic_state *state);
860void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
861				    struct drm_atomic_state *state);
862
863u32 *
864drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
865					struct drm_bridge_state *bridge_state,
866					struct drm_crtc_state *crtc_state,
867					struct drm_connector_state *conn_state,
868					u32 output_fmt,
869					unsigned int *num_input_fmts);
870
871enum drm_connector_status drm_bridge_detect(struct drm_bridge *bridge);
872int drm_bridge_get_modes(struct drm_bridge *bridge,
873			 struct drm_connector *connector);
874struct edid *drm_bridge_get_edid(struct drm_bridge *bridge,
875				 struct drm_connector *connector);
876void drm_bridge_hpd_enable(struct drm_bridge *bridge,
877			   void (*cb)(void *data,
878				      enum drm_connector_status status),
879			   void *data);
880void drm_bridge_hpd_disable(struct drm_bridge *bridge);
881void drm_bridge_hpd_notify(struct drm_bridge *bridge,
882			   enum drm_connector_status status);
883
884#ifdef CONFIG_DRM_PANEL_BRIDGE
885struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel);
886struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
887					      u32 connector_type);
888void drm_panel_bridge_remove(struct drm_bridge *bridge);
889struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
890					     struct drm_panel *panel);
891struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
892						   struct drm_panel *panel,
893						   u32 connector_type);
894struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge);
895#endif
896
897#endif