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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 paramater
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 void (*mode_set)(struct drm_bridge *bridge,
183 struct drm_display_mode *mode,
184 struct drm_display_mode *adjusted_mode);
188 * This callback should enable the bridge. It is called right before
189 * the preceding element in the display pipe is enabled. If the
190 * preceding element is a bridge this means it's called before that
191 * bridge's @pre_enable function. If the preceding element is a
192 * &drm_encoder it's called right before the encoder's
193 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
194 * &drm_encoder_helper_funcs.dpms hook.
196 * The display pipe (i.e. clocks and timing signals) feeding this bridge
197 * will not yet be running when this callback is called. The bridge must
198 * not enable the display link feeding the next bridge in the chain (if
199 * there is one) when this callback is called.
201 * The pre_enable callback is optional.
203 void (*pre_enable)(struct drm_bridge *bridge);
208 * This callback should enable the bridge. It is called right after
209 * the preceding element in the display pipe is enabled. If the
210 * preceding element is a bridge this means it's called after that
211 * bridge's @enable function. If the preceding element is a
212 * &drm_encoder it's called right after the encoder's
213 * &drm_encoder_helper_funcs.enable, &drm_encoder_helper_funcs.commit or
214 * &drm_encoder_helper_funcs.dpms hook.
216 * The bridge can assume that the display pipe (i.e. clocks and timing
217 * signals) feeding it is running when this callback is called. This
218 * callback must enable the display link feeding the next bridge in the
219 * chain if there is one.
221 * The enable callback is optional.
223 void (*enable)(struct drm_bridge *bridge);
227 * struct drm_bridge_timings - timing information for the bridge
229 struct drm_bridge_timings {
233 * Tells whether the bridge samples the digital input signal
234 * from the display engine on the positive or negative edge of the
235 * clock, this should reuse the DRM_BUS_FLAG_PIXDATA_[POS|NEG]EDGE
236 * bitwise flags from the DRM connector (bit 2 and 3 valid).
242 * Defines the time in picoseconds the input data lines must be
243 * stable before the clock edge.
249 * Defines the time in picoseconds taken for the bridge to sample the
250 * input signal after the clock edge.
256 * struct drm_bridge - central DRM bridge control structure
257 * @dev: DRM device this bridge belongs to
258 * @encoder: encoder to which this bridge is connected
259 * @next: the next bridge in the encoder chain
260 * @of_node: device node pointer to the bridge
261 * @list: to keep track of all added bridges
262 * @timings: the timing specification for the bridge, if any (may
264 * @funcs: control functions
265 * @driver_private: pointer to the bridge driver's internal context
268 struct drm_device *dev;
269 struct drm_encoder *encoder;
270 struct drm_bridge *next;
272 struct device_node *of_node;
274 struct list_head list;
275 const struct drm_bridge_timings *timings;
277 const struct drm_bridge_funcs *funcs;
278 void *driver_private;
281 void drm_bridge_add(struct drm_bridge *bridge);
282 void drm_bridge_remove(struct drm_bridge *bridge);
283 struct drm_bridge *of_drm_find_bridge(struct device_node *np);
284 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
285 struct drm_bridge *previous);
287 bool drm_bridge_mode_fixup(struct drm_bridge *bridge,
288 const struct drm_display_mode *mode,
289 struct drm_display_mode *adjusted_mode);
290 enum drm_mode_status drm_bridge_mode_valid(struct drm_bridge *bridge,
291 const struct drm_display_mode *mode);
292 void drm_bridge_disable(struct drm_bridge *bridge);
293 void drm_bridge_post_disable(struct drm_bridge *bridge);
294 void drm_bridge_mode_set(struct drm_bridge *bridge,
295 struct drm_display_mode *mode,
296 struct drm_display_mode *adjusted_mode);
297 void drm_bridge_pre_enable(struct drm_bridge *bridge);
298 void drm_bridge_enable(struct drm_bridge *bridge);
300 #ifdef CONFIG_DRM_PANEL_BRIDGE
301 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
303 void drm_panel_bridge_remove(struct drm_bridge *bridge);
304 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
305 struct drm_panel *panel,