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23 #ifndef __DRM_BRIDGE_H__
24 #define __DRM_BRIDGE_H__
26 #include <linux/list.h>
27 #include <linux/ctype.h>
28 #include <drm/drm_mode_object.h>
29 #include <drm/drm_modes.h>
32 struct drm_bridge_timings;
36 * struct drm_bridge_funcs - drm_bridge control functions
38 struct drm_bridge_funcs {
42 * This callback is invoked whenever our bridge is being attached to a
45 * The attach callback is optional.
49 * Zero on success, error code on failure.
51 int (*attach)(struct drm_bridge *bridge);
56 * This callback is invoked whenever our bridge is being detached from a
59 * The detach callback is optional.
61 void (*detach)(struct drm_bridge *bridge);
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
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().
79 * This function is optional.
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
92 * drm_mode_status Enum
94 enum drm_mode_status (*mode_valid)(struct drm_bridge *bridge,
95 const struct drm_display_mode *mode);
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.
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
111 * The mode_fixup callback is optional.
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.
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.
129 * True if an acceptable configuration is possible, false if the modeset
130 * operation should be rejected.
132 bool (*mode_fixup)(struct drm_bridge *bridge,
133 const struct drm_display_mode *mode,
134 struct drm_display_mode *adjusted_mode);
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
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.
149 * The disable callback is optional.
151 void (*disable)(struct drm_bridge *bridge);
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.
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
168 * The post_disable callback is optional.
170 void (*post_disable)(struct drm_bridge *bridge);
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
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.
189 * For atomic drivers the adjusted_mode is the mode stored in
190 * &drm_crtc_state.adjusted_mode.
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.
198 void (*mode_set)(struct drm_bridge *bridge,
199 const struct drm_display_mode *mode,
200 const struct drm_display_mode *adjusted_mode);
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.
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.
217 * The pre_enable callback is optional.
219 void (*pre_enable)(struct drm_bridge *bridge);
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.
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.
237 * The enable callback is optional.
239 void (*enable)(struct drm_bridge *bridge);
242 * @atomic_pre_enable:
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.
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.
256 * Note that this function will only be invoked in the context of an
257 * atomic commit. It will not be invoked from
258 * &drm_bridge_chain_pre_enable. It would be prudent to also provide an
259 * implementation of @pre_enable if you are expecting driver calls into
260 * &drm_bridge_chain_pre_enable.
262 * The @atomic_pre_enable callback is optional.
264 void (*atomic_pre_enable)(struct drm_bridge *bridge,
265 struct drm_atomic_state *state);
270 * This callback should enable the bridge. It is called right after
271 * the preceding element in the display pipe is enabled. If the
272 * preceding element is a bridge this means it's called after that
273 * bridge's @atomic_enable or @enable function. If the preceding element
274 * is a &drm_encoder it's called right after the encoder's
275 * &drm_encoder_helper_funcs.atomic_enable hook.
277 * The bridge can assume that the display pipe (i.e. clocks and timing
278 * signals) feeding it is running when this callback is called. This
279 * callback must enable the display link feeding the next bridge in the
280 * chain if there is one.
282 * Note that this function will only be invoked in the context of an
283 * atomic commit. It will not be invoked from &drm_bridge_chain_enable.
284 * It would be prudent to also provide an implementation of @enable if
285 * you are expecting driver calls into &drm_bridge_chain_enable.
287 * The enable callback is optional.
289 void (*atomic_enable)(struct drm_bridge *bridge,
290 struct drm_atomic_state *state);
294 * This callback should disable the bridge. It is called right before
295 * the preceding element in the display pipe is disabled. If the
296 * preceding element is a bridge this means it's called before that
297 * bridge's @atomic_disable or @disable vfunc. If the preceding element
298 * is a &drm_encoder it's called right before the
299 * &drm_encoder_helper_funcs.atomic_disable hook.
301 * The bridge can assume that the display pipe (i.e. clocks and timing
302 * signals) feeding it is still running when this callback is called.
304 * Note that this function will only be invoked in the context of an
305 * atomic commit. It will not be invoked from
306 * &drm_bridge_chain_disable. It would be prudent to also provide an
307 * implementation of @disable if you are expecting driver calls into
308 * &drm_bridge_chain_disable.
310 * The disable callback is optional.
312 void (*atomic_disable)(struct drm_bridge *bridge,
313 struct drm_atomic_state *state);
316 * @atomic_post_disable:
318 * This callback should disable the bridge. It is called right after the
319 * preceding element in the display pipe is disabled. If the preceding
320 * element is a bridge this means it's called after that bridge's
321 * @atomic_post_disable or @post_disable function. If the preceding
322 * element is a &drm_encoder it's called right after the encoder's
323 * &drm_encoder_helper_funcs.atomic_disable hook.
325 * The bridge must assume that the display pipe (i.e. clocks and timing
326 * signals) feeding it is no longer running when this callback is
329 * Note that this function will only be invoked in the context of an
330 * atomic commit. It will not be invoked from
331 * &drm_bridge_chain_post_disable.
332 * It would be prudent to also provide an implementation of
333 * @post_disable if you are expecting driver calls into
334 * &drm_bridge_chain_post_disable.
336 * The post_disable callback is optional.
338 void (*atomic_post_disable)(struct drm_bridge *bridge,
339 struct drm_atomic_state *state);
343 * struct drm_bridge_timings - timing information for the bridge
345 struct drm_bridge_timings {
349 * Tells what additional settings for the pixel data on the bus
350 * this bridge requires (like pixel signal polarity). See also
351 * &drm_display_info->bus_flags.
357 * Defines the time in picoseconds the input data lines must be
358 * stable before the clock edge.
364 * Defines the time in picoseconds taken for the bridge to sample the
365 * input signal after the clock edge.
371 * True if the bus operates in dual-link mode. The exact meaning is
372 * dependent on the bus type. For LVDS buses, this indicates that even-
373 * and odd-numbered pixels are received on separate links.
379 * struct drm_bridge - central DRM bridge control structure
382 /** @dev: DRM device this bridge belongs to */
383 struct drm_device *dev;
384 /** @encoder: encoder to which this bridge is connected */
385 struct drm_encoder *encoder;
386 /** @next: the next bridge in the encoder chain */
387 struct drm_bridge *next;
389 /** @of_node: device node pointer to the bridge */
390 struct device_node *of_node;
392 /** @list: to keep track of all added bridges */
393 struct list_head list;
397 * the timing specification for the bridge, if any (may be NULL)
399 const struct drm_bridge_timings *timings;
400 /** @funcs: control functions */
401 const struct drm_bridge_funcs *funcs;
402 /** @driver_private: pointer to the bridge driver's internal context */
403 void *driver_private;
406 void drm_bridge_add(struct drm_bridge *bridge);
407 void drm_bridge_remove(struct drm_bridge *bridge);
408 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
409 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
410 struct drm_bridge *previous);
413 * drm_bridge_get_next_bridge() - Get the next bridge in the chain
414 * @bridge: bridge object
417 * the next bridge in the chain after @bridge, or NULL if @bridge is the last.
419 static inline struct drm_bridge *
420 drm_bridge_get_next_bridge(struct drm_bridge *bridge)
425 bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,
426 const struct drm_display_mode *mode,
427 struct drm_display_mode *adjusted_mode);
429 drm_bridge_chain_mode_valid(struct drm_bridge *bridge,
430 const struct drm_display_mode *mode);
431 void drm_bridge_chain_disable(struct drm_bridge *bridge);
432 void drm_bridge_chain_post_disable(struct drm_bridge *bridge);
433 void drm_bridge_chain_mode_set(struct drm_bridge *bridge,
434 const struct drm_display_mode *mode,
435 const struct drm_display_mode *adjusted_mode);
436 void drm_bridge_chain_pre_enable(struct drm_bridge *bridge);
437 void drm_bridge_chain_enable(struct drm_bridge *bridge);
439 void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,
440 struct drm_atomic_state *state);
441 void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
442 struct drm_atomic_state *state);
443 void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,
444 struct drm_atomic_state *state);
445 void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,
446 struct drm_atomic_state *state);
448 #ifdef CONFIG_DRM_PANEL_BRIDGE
449 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
451 void drm_panel_bridge_remove(struct drm_bridge *bridge);
452 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
453 struct drm_panel *panel,