17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
45  *     [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
52  * Display drivers are responsible for linking encoders with the first bridge
73  * For display drivers that use the atomic helpers
76  * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
77  * commit check and commit tail handlers, or through the higher-level
84  * the bridge chain. Display drivers may use the drm_bridge_connector_init()
86  * connector-related operations exposed by the bridge (see the overview
99  * drm_bridge_add - add the given bridge to the global bridge list
105 	mutex_init(&bridge->hpd_mutex);  in drm_bridge_add()
108 	list_add_tail(&bridge->list, &bridge_list);  in drm_bridge_add()
114  * drm_bridge_remove - remove the given bridge from the global bridge list
121 	list_del_init(&bridge->list);  in drm_bridge_remove()
124 	mutex_destroy(&bridge->hpd_mutex);  in drm_bridge_remove()
134 	state = bridge->funcs->atomic_duplicate_state(bridge);  in drm_bridge_atomic_duplicate_priv_state()
135 	return state ? &state->base : NULL;  in drm_bridge_atomic_duplicate_priv_state()
145 	bridge->funcs->atomic_destroy_state(bridge, state);  in drm_bridge_atomic_destroy_priv_state()
154  * drm_bridge_attach - attach the bridge to an encoder's chain
166  * If non-NULL the previous bridge must be already attached by a call to this
169  * Note that bridges attached to encoders are auto-detached during encoder
183 		return -EINVAL;  in drm_bridge_attach()
185 	if (previous && (!previous->dev || previous->encoder != encoder))  in drm_bridge_attach()
186 		return -EINVAL;  in drm_bridge_attach()
188 	if (bridge->dev)  in drm_bridge_attach()
189 		return -EBUSY;  in drm_bridge_attach()
191 	bridge->dev = encoder->dev;  in drm_bridge_attach()
192 	bridge->encoder = encoder;  in drm_bridge_attach()
195 		list_add(&bridge->chain_node, &previous->chain_node);  in drm_bridge_attach()
197 		list_add(&bridge->chain_node, &encoder->bridge_chain);  in drm_bridge_attach()
199 	if (bridge->funcs->attach) {  in drm_bridge_attach()
200 		ret = bridge->funcs->attach(bridge, flags);  in drm_bridge_attach()
205 	if (bridge->funcs->atomic_reset) {  in drm_bridge_attach()
208 		state = bridge->funcs->atomic_reset(bridge);  in drm_bridge_attach()
214 		drm_atomic_private_obj_init(bridge->dev, &bridge->base,  in drm_bridge_attach()
215 					    &state->base,  in drm_bridge_attach()
222 	if (bridge->funcs->detach)  in drm_bridge_attach()
223 		bridge->funcs->detach(bridge);  in drm_bridge_attach()
226 	bridge->dev = NULL;  in drm_bridge_attach()
227 	bridge->encoder = NULL;  in drm_bridge_attach()
228 	list_del(&bridge->chain_node);  in drm_bridge_attach()
232 		  bridge->of_node, encoder->name, ret);  in drm_bridge_attach()
235 		  encoder->name, ret);  in drm_bridge_attach()
247 	if (WARN_ON(!bridge->dev))  in drm_bridge_detach()
250 	if (bridge->funcs->atomic_reset)  in drm_bridge_detach()
251 		drm_atomic_private_obj_fini(&bridge->base);  in drm_bridge_detach()
253 	if (bridge->funcs->detach)  in drm_bridge_detach()
254 		bridge->funcs->detach(bridge);  in drm_bridge_detach()
256 	list_del(&bridge->chain_node);  in drm_bridge_detach()
257 	bridge->dev = NULL;  in drm_bridge_detach()
268  * - The encoder-related operations support control of the bridges in the
277  *   finer-grained control.
284  *   Mixing atomic and non-atomic versions of the operations is not supported.
286  * - The bus format negotiation operations
291  *   transparently for display drivers by the atomic modeset helpers. Only
294  *   encoder-related operations. This feature is not supported by the legacy
297  * - The connector-related operations support implementing a &drm_connector
308  *   an externally-implemented &drm_connector. Those operations are
312  *   implemented, display drivers shall create a &drm_connector instance for
316  *   Bridge drivers shall implement the connector-related operations for all
321  *   controller of the SoC. Support for the connector-related operations on the
328  *   flag will be set. Display drivers shall use the &drm_bridge.ops flags to
332  *   read-only memory.
336  *   connected-related bridge operations. Connector creation is then controlled
337  *   by the flags argument to the drm_bridge_attach() function. Display drivers
344  *   %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
350  * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the
373 	encoder = bridge->encoder;  in drm_bridge_chain_mode_fixup()
374 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_fixup()
375 		if (!bridge->funcs->mode_fixup)  in drm_bridge_chain_mode_fixup()
378 		if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))  in drm_bridge_chain_mode_fixup()
387  * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
390  * @info: display info against which the mode shall be validated
412 	encoder = bridge->encoder;  in drm_bridge_chain_mode_valid()
413 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_valid()
416 		if (!bridge->funcs->mode_valid)  in drm_bridge_chain_mode_valid()
419 		ret = bridge->funcs->mode_valid(bridge, info, mode);  in drm_bridge_chain_mode_valid()
429  * drm_bridge_chain_disable - disables all bridges in the encoder chain
446 	encoder = bridge->encoder;  in drm_bridge_chain_disable()
447 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_disable()
448 		if (iter->funcs->disable)  in drm_bridge_chain_disable()
449 			iter->funcs->disable(iter);  in drm_bridge_chain_disable()
458  * drm_bridge_chain_post_disable - cleans up after disabling all bridges in the
475 	encoder = bridge->encoder;  in drm_bridge_chain_post_disable()
476 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_post_disable()
477 		if (bridge->funcs->post_disable)  in drm_bridge_chain_post_disable()
478 			bridge->funcs->post_disable(bridge);  in drm_bridge_chain_post_disable()
484  * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
504 	encoder = bridge->encoder;  in drm_bridge_chain_mode_set()
505 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_set()
506 		if (bridge->funcs->mode_set)  in drm_bridge_chain_mode_set()
507 			bridge->funcs->mode_set(bridge, mode, adjusted_mode);  in drm_bridge_chain_mode_set()
513  * drm_bridge_chain_pre_enable - prepares for enabling all bridges in the
531 	encoder = bridge->encoder;  in drm_bridge_chain_pre_enable()
532 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_pre_enable()
533 		if (iter->funcs->pre_enable)  in drm_bridge_chain_pre_enable()
534 			iter->funcs->pre_enable(iter);  in drm_bridge_chain_pre_enable()
543  * drm_bridge_chain_enable - enables all bridges in the encoder chain
559 	encoder = bridge->encoder;  in drm_bridge_chain_enable()
560 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_enable()
561 		if (bridge->funcs->enable)  in drm_bridge_chain_enable()
562 			bridge->funcs->enable(bridge);  in drm_bridge_chain_enable()
568  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
588 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_disable()
589 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_disable()
590 		if (iter->funcs->atomic_disable) {  in drm_atomic_bridge_chain_disable()
599 			iter->funcs->atomic_disable(iter, old_bridge_state);  in drm_atomic_bridge_chain_disable()
600 		} else if (iter->funcs->disable) {  in drm_atomic_bridge_chain_disable()
601 			iter->funcs->disable(iter);  in drm_atomic_bridge_chain_disable()
611  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
631 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_post_disable()
632 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_post_disable()
633 		if (bridge->funcs->atomic_post_disable) {  in drm_atomic_bridge_chain_post_disable()
642 			bridge->funcs->atomic_post_disable(bridge,  in drm_atomic_bridge_chain_post_disable()
644 		} else if (bridge->funcs->post_disable) {  in drm_atomic_bridge_chain_post_disable()
645 			bridge->funcs->post_disable(bridge);  in drm_atomic_bridge_chain_post_disable()
652  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
673 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_pre_enable()
674 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
675 		if (iter->funcs->atomic_pre_enable) {  in drm_atomic_bridge_chain_pre_enable()
684 			iter->funcs->atomic_pre_enable(iter, old_bridge_state);  in drm_atomic_bridge_chain_pre_enable()
685 		} else if (iter->funcs->pre_enable) {  in drm_atomic_bridge_chain_pre_enable()
686 			iter->funcs->pre_enable(iter);  in drm_atomic_bridge_chain_pre_enable()
696  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
715 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_enable()
716 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_enable()
717 		if (bridge->funcs->atomic_enable) {  in drm_atomic_bridge_chain_enable()
726 			bridge->funcs->atomic_enable(bridge, old_bridge_state);  in drm_atomic_bridge_chain_enable()
727 		} else if (bridge->funcs->enable) {  in drm_atomic_bridge_chain_enable()
728 			bridge->funcs->enable(bridge);  in drm_atomic_bridge_chain_enable()
738 	if (bridge->funcs->atomic_check) {  in drm_atomic_bridge_check()
742 		bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_check()
745 			return -EINVAL;  in drm_atomic_bridge_check()
747 		ret = bridge->funcs->atomic_check(bridge, bridge_state,  in drm_atomic_bridge_check()
751 	} else if (bridge->funcs->mode_fixup) {  in drm_atomic_bridge_check()
752 		if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,  in drm_atomic_bridge_check()
753 					       &crtc_state->adjusted_mode))  in drm_atomic_bridge_check()
754 			return -EINVAL;  in drm_atomic_bridge_check()
773 	cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in select_bus_fmt_recursive()
782 	if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {  in select_bus_fmt_recursive()
797 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;  in select_bus_fmt_recursive()
798 			cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
805 	 * If the driver implements ->atomic_get_input_bus_fmts() it  in select_bus_fmt_recursive()
809 		return -EINVAL;  in select_bus_fmt_recursive()
811 	in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,  in select_bus_fmt_recursive()
818 		return -ENOTSUPP;  in select_bus_fmt_recursive()
820 		return -ENOMEM;  in select_bus_fmt_recursive()
823 		cur_state->input_bus_cfg.format = in_bus_fmts[0];  in select_bus_fmt_recursive()
824 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
833 		if (ret != -ENOTSUPP)  in select_bus_fmt_recursive()
838 		cur_state->input_bus_cfg.format = in_bus_fmts[i];  in select_bus_fmt_recursive()
839 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
858  * support transcoding into a specific output format -ENOTSUPP is returned and
860  * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
885 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_select_bus_fmts()
886 	struct drm_encoder *encoder = bridge->encoder;  in drm_atomic_bridge_chain_select_bus_fmts()
893 	last_bridge = list_last_entry(&encoder->bridge_chain,  in drm_atomic_bridge_chain_select_bus_fmts()
895 	last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_chain_select_bus_fmts()
898 	if (last_bridge->funcs->atomic_get_output_bus_fmts) {  in drm_atomic_bridge_chain_select_bus_fmts()
899 		const struct drm_bridge_funcs *funcs = last_bridge->funcs;  in drm_atomic_bridge_chain_select_bus_fmts()
902 		 * If the driver implements ->atomic_get_output_bus_fmts() it  in drm_atomic_bridge_chain_select_bus_fmts()
906 			return -EINVAL;  in drm_atomic_bridge_chain_select_bus_fmts()
908 		out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,  in drm_atomic_bridge_chain_select_bus_fmts()
914 			return -ENOTSUPP;  in drm_atomic_bridge_chain_select_bus_fmts()
916 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
921 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
923 		if (conn->display_info.num_bus_formats &&  in drm_atomic_bridge_chain_select_bus_fmts()
924 		    conn->display_info.bus_formats)  in drm_atomic_bridge_chain_select_bus_fmts()
925 			out_bus_fmts[0] = conn->display_info.bus_formats[0];  in drm_atomic_bridge_chain_select_bus_fmts()
933 		if (ret != -ENOTSUPP)  in drm_atomic_bridge_chain_select_bus_fmts()
970 		output_flags = conn->display_info.bus_flags;  in drm_atomic_bridge_propagate_bus_flags()
979 			output_flags = next_bridge_state->input_bus_cfg.flags;  in drm_atomic_bridge_propagate_bus_flags()
982 	bridge_state->output_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
990 	bridge_state->input_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
994  * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1012 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_check()
1025 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_check()
1026 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_check()
1037 						      crtc_state->state);  in drm_atomic_bridge_chain_check()
1052  * drm_bridge_detect - check if anything is attached to the bridge output
1066 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))  in drm_bridge_detect()
1069 	return bridge->funcs->detect(bridge);  in drm_bridge_detect()
1074  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1090 	if (!(bridge->ops & DRM_BRIDGE_OP_MODES))  in drm_bridge_get_modes()
1093 	return bridge->funcs->get_modes(bridge, connector);  in drm_bridge_get_modes()
1098  * drm_bridge_get_edid - get the EDID data of the connected display
1112 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))  in drm_bridge_get_edid()
1115 	return bridge->funcs->get_edid(bridge, connector);  in drm_bridge_get_edid()
1120  * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1122  * @cb: hot-plug detection callback
1123  * @data: data to be passed to the hot-plug detection callback
1131  * bridge->ops. This function shall not be called when the flag is not set.
1142 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_enable()
1145 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1147 	if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))  in drm_bridge_hpd_enable()
1150 	bridge->hpd_cb = cb;  in drm_bridge_hpd_enable()
1151 	bridge->hpd_data = data;  in drm_bridge_hpd_enable()
1153 	if (bridge->funcs->hpd_enable)  in drm_bridge_hpd_enable()
1154 		bridge->funcs->hpd_enable(bridge);  in drm_bridge_hpd_enable()
1157 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1162  * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1171  * bridge->ops. This function shall not be called when the flag is not set.
1175 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_disable()
1178 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1179 	if (bridge->funcs->hpd_disable)  in drm_bridge_hpd_disable()
1180 		bridge->funcs->hpd_disable(bridge);  in drm_bridge_hpd_disable()
1182 	bridge->hpd_cb = NULL;  in drm_bridge_hpd_disable()
1183 	bridge->hpd_data = NULL;  in drm_bridge_hpd_disable()
1184 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1189  * drm_bridge_hpd_notify - notify hot plug detection events
1202 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1203 	if (bridge->hpd_cb)  in drm_bridge_hpd_notify()
1204 		bridge->hpd_cb(bridge->hpd_data, status);  in drm_bridge_hpd_notify()
1205 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1211  * of_drm_find_bridge - find the bridge corresponding to the device node in
1226 		if (bridge->of_node == np) {  in of_drm_find_bridge()