17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
44  *     [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
51  * Display drivers are responsible for linking encoders with the first bridge
72  * For display drivers that use the atomic helpers
75  * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
76  * commit check and commit tail handlers, or through the higher-level
83  * the bridge chain. Display drivers may use the drm_bridge_connector_init()
85  * connector-related operations exposed by the bridge (see the overview
98  * drm_bridge_add - add the given bridge to the global bridge list
104 	mutex_init(&bridge->hpd_mutex);  in drm_bridge_add()
107 	list_add_tail(&bridge->list, &bridge_list);  in drm_bridge_add()
113  * drm_bridge_remove - remove the given bridge from the global bridge list
120 	list_del_init(&bridge->list);  in drm_bridge_remove()
123 	mutex_destroy(&bridge->hpd_mutex);  in drm_bridge_remove()
133 	state = bridge->funcs->atomic_duplicate_state(bridge);  in drm_bridge_atomic_duplicate_priv_state()
134 	return state ? &state->base : NULL;  in drm_bridge_atomic_duplicate_priv_state()
144 	bridge->funcs->atomic_destroy_state(bridge, state);  in drm_bridge_atomic_destroy_priv_state()
153  * drm_bridge_attach - attach the bridge to an encoder's chain
165  * If non-NULL the previous bridge must be already attached by a call to this
168  * Note that bridges attached to encoders are auto-detached during encoder
182 		return -EINVAL;  in drm_bridge_attach()
184 	if (previous && (!previous->dev || previous->encoder != encoder))  in drm_bridge_attach()
185 		return -EINVAL;  in drm_bridge_attach()
187 	if (bridge->dev)  in drm_bridge_attach()
188 		return -EBUSY;  in drm_bridge_attach()
190 	bridge->dev = encoder->dev;  in drm_bridge_attach()
191 	bridge->encoder = encoder;  in drm_bridge_attach()
194 		list_add(&bridge->chain_node, &previous->chain_node);  in drm_bridge_attach()
196 		list_add(&bridge->chain_node, &encoder->bridge_chain);  in drm_bridge_attach()
198 	if (bridge->funcs->attach) {  in drm_bridge_attach()
199 		ret = bridge->funcs->attach(bridge, flags);  in drm_bridge_attach()
204 	if (bridge->funcs->atomic_reset) {  in drm_bridge_attach()
207 		state = bridge->funcs->atomic_reset(bridge);  in drm_bridge_attach()
213 		drm_atomic_private_obj_init(bridge->dev, &bridge->base,  in drm_bridge_attach()
214 					    &state->base,  in drm_bridge_attach()
221 	if (bridge->funcs->detach)  in drm_bridge_attach()
222 		bridge->funcs->detach(bridge);  in drm_bridge_attach()
225 	bridge->dev = NULL;  in drm_bridge_attach()
226 	bridge->encoder = NULL;  in drm_bridge_attach()
227 	list_del(&bridge->chain_node);  in drm_bridge_attach()
237 	if (WARN_ON(!bridge->dev))  in drm_bridge_detach()
240 	if (bridge->funcs->atomic_reset)  in drm_bridge_detach()
241 		drm_atomic_private_obj_fini(&bridge->base);  in drm_bridge_detach()
243 	if (bridge->funcs->detach)  in drm_bridge_detach()
244 		bridge->funcs->detach(bridge);  in drm_bridge_detach()
246 	list_del(&bridge->chain_node);  in drm_bridge_detach()
247 	bridge->dev = NULL;  in drm_bridge_detach()
258  * - The encoder-related operations support control of the bridges in the
267  *   finer-grained control.
274  *   Mixing atomic and non-atomic versions of the operations is not supported.
276  * - The bus format negotiation operations
281  *   transparently for display drivers by the atomic modeset helpers. Only
284  *   encoder-related operations. This feature is not supported by the legacy
287  * - The connector-related operations support implementing a &drm_connector
298  *   an externally-implemented &drm_connector. Those operations are
302  *   implemented, display drivers shall create a &drm_connector instance for
306  *   Bridge drivers shall implement the connector-related operations for all
311  *   controller of the SoC. Support for the connector-related operations on the
318  *   flag will be set. Display drivers shall use the &drm_bridge.ops flags to
322  *   read-only memory.
326  *   connected-related bridge operations. Connector creation is then controlled
327  *   by the flags argument to the drm_bridge_attach() function. Display drivers
334  *   %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
340  * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the
363 	encoder = bridge->encoder;  in drm_bridge_chain_mode_fixup()
364 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_fixup()
365 		if (!bridge->funcs->mode_fixup)  in drm_bridge_chain_mode_fixup()
368 		if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))  in drm_bridge_chain_mode_fixup()
377  * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
380  * @info: display info against which the mode shall be validated
402 	encoder = bridge->encoder;  in drm_bridge_chain_mode_valid()
403 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_valid()
406 		if (!bridge->funcs->mode_valid)  in drm_bridge_chain_mode_valid()
409 		ret = bridge->funcs->mode_valid(bridge, info, mode);  in drm_bridge_chain_mode_valid()
419  * drm_bridge_chain_disable - disables all bridges in the encoder chain
436 	encoder = bridge->encoder;  in drm_bridge_chain_disable()
437 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_disable()
438 		if (iter->funcs->disable)  in drm_bridge_chain_disable()
439 			iter->funcs->disable(iter);  in drm_bridge_chain_disable()
448  * drm_bridge_chain_post_disable - cleans up after disabling all bridges in the
465 	encoder = bridge->encoder;  in drm_bridge_chain_post_disable()
466 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_post_disable()
467 		if (bridge->funcs->post_disable)  in drm_bridge_chain_post_disable()
468 			bridge->funcs->post_disable(bridge);  in drm_bridge_chain_post_disable()
474  * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
494 	encoder = bridge->encoder;  in drm_bridge_chain_mode_set()
495 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_set()
496 		if (bridge->funcs->mode_set)  in drm_bridge_chain_mode_set()
497 			bridge->funcs->mode_set(bridge, mode, adjusted_mode);  in drm_bridge_chain_mode_set()
503  * drm_bridge_chain_pre_enable - prepares for enabling all bridges in the
521 	encoder = bridge->encoder;  in drm_bridge_chain_pre_enable()
522 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_pre_enable()
523 		if (iter->funcs->pre_enable)  in drm_bridge_chain_pre_enable()
524 			iter->funcs->pre_enable(iter);  in drm_bridge_chain_pre_enable()
530  * drm_bridge_chain_enable - enables all bridges in the encoder chain
546 	encoder = bridge->encoder;  in drm_bridge_chain_enable()
547 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_enable()
548 		if (bridge->funcs->enable)  in drm_bridge_chain_enable()
549 			bridge->funcs->enable(bridge);  in drm_bridge_chain_enable()
555  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
575 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_disable()
576 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_disable()
577 		if (iter->funcs->atomic_disable) {  in drm_atomic_bridge_chain_disable()
586 			iter->funcs->atomic_disable(iter, old_bridge_state);  in drm_atomic_bridge_chain_disable()
587 		} else if (iter->funcs->disable) {  in drm_atomic_bridge_chain_disable()
588 			iter->funcs->disable(iter);  in drm_atomic_bridge_chain_disable()
598  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
618 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_post_disable()
619 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_post_disable()
620 		if (bridge->funcs->atomic_post_disable) {  in drm_atomic_bridge_chain_post_disable()
629 			bridge->funcs->atomic_post_disable(bridge,  in drm_atomic_bridge_chain_post_disable()
631 		} else if (bridge->funcs->post_disable) {  in drm_atomic_bridge_chain_post_disable()
632 			bridge->funcs->post_disable(bridge);  in drm_atomic_bridge_chain_post_disable()
639  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
660 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_pre_enable()
661 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
662 		if (iter->funcs->atomic_pre_enable) {  in drm_atomic_bridge_chain_pre_enable()
671 			iter->funcs->atomic_pre_enable(iter, old_bridge_state);  in drm_atomic_bridge_chain_pre_enable()
672 		} else if (iter->funcs->pre_enable) {  in drm_atomic_bridge_chain_pre_enable()
673 			iter->funcs->pre_enable(iter);  in drm_atomic_bridge_chain_pre_enable()
683  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
702 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_enable()
703 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_enable()
704 		if (bridge->funcs->atomic_enable) {  in drm_atomic_bridge_chain_enable()
713 			bridge->funcs->atomic_enable(bridge, old_bridge_state);  in drm_atomic_bridge_chain_enable()
714 		} else if (bridge->funcs->enable) {  in drm_atomic_bridge_chain_enable()
715 			bridge->funcs->enable(bridge);  in drm_atomic_bridge_chain_enable()
725 	if (bridge->funcs->atomic_check) {  in drm_atomic_bridge_check()
729 		bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_check()
732 			return -EINVAL;  in drm_atomic_bridge_check()
734 		ret = bridge->funcs->atomic_check(bridge, bridge_state,  in drm_atomic_bridge_check()
738 	} else if (bridge->funcs->mode_fixup) {  in drm_atomic_bridge_check()
739 		if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,  in drm_atomic_bridge_check()
740 					       &crtc_state->adjusted_mode))  in drm_atomic_bridge_check()
741 			return -EINVAL;  in drm_atomic_bridge_check()
760 	cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in select_bus_fmt_recursive()
769 	if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {  in select_bus_fmt_recursive()
784 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;  in select_bus_fmt_recursive()
785 			cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
792 	 * If the driver implements ->atomic_get_input_bus_fmts() it  in select_bus_fmt_recursive()
796 		return -EINVAL;  in select_bus_fmt_recursive()
798 	in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,  in select_bus_fmt_recursive()
805 		return -ENOTSUPP;  in select_bus_fmt_recursive()
807 		return -ENOMEM;  in select_bus_fmt_recursive()
810 		cur_state->input_bus_cfg.format = in_bus_fmts[0];  in select_bus_fmt_recursive()
811 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
820 		if (ret != -ENOTSUPP)  in select_bus_fmt_recursive()
825 		cur_state->input_bus_cfg.format = in_bus_fmts[i];  in select_bus_fmt_recursive()
826 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
845  * support transcoding into a specific output format -ENOTSUPP is returned and
847  * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
872 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_select_bus_fmts()
873 	struct drm_encoder *encoder = bridge->encoder;  in drm_atomic_bridge_chain_select_bus_fmts()
880 	last_bridge = list_last_entry(&encoder->bridge_chain,  in drm_atomic_bridge_chain_select_bus_fmts()
882 	last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_chain_select_bus_fmts()
885 	if (last_bridge->funcs->atomic_get_output_bus_fmts) {  in drm_atomic_bridge_chain_select_bus_fmts()
886 		const struct drm_bridge_funcs *funcs = last_bridge->funcs;  in drm_atomic_bridge_chain_select_bus_fmts()
889 		 * If the driver implements ->atomic_get_output_bus_fmts() it  in drm_atomic_bridge_chain_select_bus_fmts()
893 			return -EINVAL;  in drm_atomic_bridge_chain_select_bus_fmts()
895 		out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,  in drm_atomic_bridge_chain_select_bus_fmts()
901 			return -ENOTSUPP;  in drm_atomic_bridge_chain_select_bus_fmts()
903 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
908 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
910 		if (conn->display_info.num_bus_formats &&  in drm_atomic_bridge_chain_select_bus_fmts()
911 		    conn->display_info.bus_formats)  in drm_atomic_bridge_chain_select_bus_fmts()
912 			out_bus_fmts[0] = conn->display_info.bus_formats[0];  in drm_atomic_bridge_chain_select_bus_fmts()
920 		if (ret != -ENOTSUPP)  in drm_atomic_bridge_chain_select_bus_fmts()
957 		output_flags = conn->display_info.bus_flags;  in drm_atomic_bridge_propagate_bus_flags()
966 			output_flags = next_bridge_state->input_bus_cfg.flags;  in drm_atomic_bridge_propagate_bus_flags()
969 	bridge_state->output_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
977 	bridge_state->input_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
981  * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
999 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_check()
1012 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_check()
1013 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_check()
1024 						      crtc_state->state);  in drm_atomic_bridge_chain_check()
1039  * drm_bridge_detect - check if anything is attached to the bridge output
1053 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))  in drm_bridge_detect()
1056 	return bridge->funcs->detect(bridge);  in drm_bridge_detect()
1061  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1077 	if (!(bridge->ops & DRM_BRIDGE_OP_MODES))  in drm_bridge_get_modes()
1080 	return bridge->funcs->get_modes(bridge, connector);  in drm_bridge_get_modes()
1085  * drm_bridge_get_edid - get the EDID data of the connected display
1099 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))  in drm_bridge_get_edid()
1102 	return bridge->funcs->get_edid(bridge, connector);  in drm_bridge_get_edid()
1107  * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1109  * @cb: hot-plug detection callback
1110  * @data: data to be passed to the hot-plug detection callback
1118  * bridge->ops. This function shall not be called when the flag is not set.
1129 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_enable()
1132 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1134 	if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))  in drm_bridge_hpd_enable()
1137 	bridge->hpd_cb = cb;  in drm_bridge_hpd_enable()
1138 	bridge->hpd_data = data;  in drm_bridge_hpd_enable()
1140 	if (bridge->funcs->hpd_enable)  in drm_bridge_hpd_enable()
1141 		bridge->funcs->hpd_enable(bridge);  in drm_bridge_hpd_enable()
1144 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1149  * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1158  * bridge->ops. This function shall not be called when the flag is not set.
1162 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_disable()
1165 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1166 	if (bridge->funcs->hpd_disable)  in drm_bridge_hpd_disable()
1167 		bridge->funcs->hpd_disable(bridge);  in drm_bridge_hpd_disable()
1169 	bridge->hpd_cb = NULL;  in drm_bridge_hpd_disable()
1170 	bridge->hpd_data = NULL;  in drm_bridge_hpd_disable()
1171 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1176  * drm_bridge_hpd_notify - notify hot plug detection events
1189 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1190 	if (bridge->hpd_cb)  in drm_bridge_hpd_notify()
1191 		bridge->hpd_cb(bridge->hpd_data, status);  in drm_bridge_hpd_notify()
1192 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1198  * of_drm_find_bridge - find the bridge corresponding to the device node in
1213 		if (bridge->of_node == np) {  in of_drm_find_bridge()