17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
25 #include <linux/media-bus-format.h>
50  *     [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
80  * and disable (through drm_atomic_bridge_chain_disable() and
88  * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
89  * commit check and commit tail handlers, or through the higher-level
98  * connector-related operations exposed by the bridge (see the overview
110  * - The upstream driver doesn't use the component framework and isn't a
111  *   MIPI-DSI host. In this case, the bridge driver will probe at some
115  * - The upstream driver doesn't use the component framework, but is a
116  *   MIPI-DSI host. The bridge device uses the MIPI-DCS commands to be
119  *   device (and MIPI-DSI host) is present. The upstream driver will be
126  * - The upstream driver uses the component framework and is a MIPI-DSI
127  *   host. The bridge device uses the MIPI-DCS commands to be
131  * - The upstream driver uses the component framework and is a MIPI-DSI
139  * MIPI-DSI host driver case) is to split the operations like this:
141  * - The MIPI-DSI host driver must run mipi_dsi_host_register() in its
142  *   probe hook. It will make sure that the MIPI-DSI host sticks around,
145  * - In its probe hook, the bridge driver must try to find its MIPI-DSI
146  *   host, register as a MIPI-DSI device and attach the MIPI-DSI device
149  * - In its &struct mipi_dsi_host_ops.attach hook, the MIPI-DSI host can
155  * the bridge driver are functional and we can't have a deadlock-like
168  * must not be assumed that it is LP-11.
169  * pre_enable should initialise the PHY, set the data lanes to LP-11, and the
170  * clock lane to either LP-11 or HS depending on the mode_flag
174  * called before the DSI host. If the DSI peripheral requires LP-11 and/or
175  * the clock lane to be in HS mode prior to pre_enable, then it can set the
182  * The reverse also applies. The DSI host disable operation or stopping the CRTC
183  * should stop transmitting video, and the data lanes should return to the LP-11
184  * state. The DSI host &post_disable operation should disable the PHY.
190  * DSI host should initialise the interface, transmit the data, and then disable
202  * drm_bridge_add - add the given bridge to the global bridge list
208 	mutex_init(&bridge->hpd_mutex);  in drm_bridge_add()
211 	list_add_tail(&bridge->list, &bridge_list);  in drm_bridge_add()
222  * devm_drm_bridge_add - devm managed version of drm_bridge_add()
240  * drm_bridge_remove - remove the given bridge from the global bridge list
247 	list_del_init(&bridge->list);  in drm_bridge_remove()
250 	mutex_destroy(&bridge->hpd_mutex);  in drm_bridge_remove()
260 	state = bridge->funcs->atomic_duplicate_state(bridge);  in drm_bridge_atomic_duplicate_priv_state()
261 	return state ? &state->base : NULL;  in drm_bridge_atomic_duplicate_priv_state()
271 	bridge->funcs->atomic_destroy_state(bridge, state);  in drm_bridge_atomic_destroy_priv_state()
280  * drm_bridge_attach - attach the bridge to an encoder's chain
292  * If non-NULL the previous bridge must be already attached by a call to this
295  * Note that bridges attached to encoders are auto-detached during encoder
309 		return -EINVAL;  in drm_bridge_attach()
311 	if (previous && (!previous->dev || previous->encoder != encoder))  in drm_bridge_attach()
312 		return -EINVAL;  in drm_bridge_attach()
314 	if (bridge->dev)  in drm_bridge_attach()
315 		return -EBUSY;  in drm_bridge_attach()
317 	bridge->dev = encoder->dev;  in drm_bridge_attach()
318 	bridge->encoder = encoder;  in drm_bridge_attach()
321 		list_add(&bridge->chain_node, &previous->chain_node);  in drm_bridge_attach()
323 		list_add(&bridge->chain_node, &encoder->bridge_chain);  in drm_bridge_attach()
325 	if (bridge->funcs->attach) {  in drm_bridge_attach()
326 		ret = bridge->funcs->attach(bridge, flags);  in drm_bridge_attach()
331 	if (bridge->funcs->atomic_reset) {  in drm_bridge_attach()
334 		state = bridge->funcs->atomic_reset(bridge);  in drm_bridge_attach()
340 		drm_atomic_private_obj_init(bridge->dev, &bridge->base,  in drm_bridge_attach()
341 					    &state->base,  in drm_bridge_attach()
348 	if (bridge->funcs->detach)  in drm_bridge_attach()
349 		bridge->funcs->detach(bridge);  in drm_bridge_attach()
352 	bridge->dev = NULL;  in drm_bridge_attach()
353 	bridge->encoder = NULL;  in drm_bridge_attach()
354 	list_del(&bridge->chain_node);  in drm_bridge_attach()
356 	if (ret != -EPROBE_DEFER)  in drm_bridge_attach()
358 			  bridge->of_node, encoder->name, ret);  in drm_bridge_attach()
360 		dev_err_probe(encoder->dev->dev, -EPROBE_DEFER,  in drm_bridge_attach()
362 			      bridge->of_node, encoder->name);  in drm_bridge_attach()
373 	if (WARN_ON(!bridge->dev))  in drm_bridge_detach()
376 	if (bridge->funcs->atomic_reset)  in drm_bridge_detach()
377 		drm_atomic_private_obj_fini(&bridge->base);  in drm_bridge_detach()
379 	if (bridge->funcs->detach)  in drm_bridge_detach()
380 		bridge->funcs->detach(bridge);  in drm_bridge_detach()
382 	list_del(&bridge->chain_node);  in drm_bridge_detach()
383 	bridge->dev = NULL;  in drm_bridge_detach()
394  * - The encoder-related operations support control of the bridges in the
398  *   disable the bridge automatically.
400  *   The enable and disable operations are split in
402  *   &drm_bridge_funcs.disable and &drm_bridge_funcs.post_disable to provide
403  *   finer-grained control.
410  *   Mixing atomic and non-atomic versions of the operations is not supported.
412  * - The bus format negotiation operations
420  *   encoder-related operations. This feature is not supported by the legacy
423  * - The connector-related operations support implementing a &drm_connector
434  *   an externally-implemented &drm_connector. Those operations are
442  *   Bridge drivers shall implement the connector-related operations for all
447  *   controller of the SoC. Support for the connector-related operations on the
458  *   read-only memory.
462  *   connected-related bridge operations. Connector creation is then controlled
476  * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
501 	encoder = bridge->encoder;  in drm_bridge_chain_mode_valid()
502 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_valid()
505 		if (!bridge->funcs->mode_valid)  in drm_bridge_chain_mode_valid()
508 		ret = bridge->funcs->mode_valid(bridge, info, mode);  in drm_bridge_chain_mode_valid()
518  * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
538 	encoder = bridge->encoder;  in drm_bridge_chain_mode_set()
539 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_set()
540 		if (bridge->funcs->mode_set)  in drm_bridge_chain_mode_set()
541 			bridge->funcs->mode_set(bridge, mode, adjusted_mode);  in drm_bridge_chain_mode_set()
547  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
552  * &drm_bridge_funcs.disable) op for all the bridges in the encoder chain,
567 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_disable()
568 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_disable()
569 		if (iter->funcs->atomic_disable) {  in drm_atomic_bridge_chain_disable()
578 			iter->funcs->atomic_disable(iter, old_bridge_state);  in drm_atomic_bridge_chain_disable()
579 		} else if (iter->funcs->disable) {  in drm_atomic_bridge_chain_disable()
580 			iter->funcs->disable(iter);  in drm_atomic_bridge_chain_disable()
592 	if (old_state && bridge->funcs->atomic_post_disable) {  in drm_atomic_bridge_call_post_disable()
601 		bridge->funcs->atomic_post_disable(bridge,  in drm_atomic_bridge_call_post_disable()
603 	} else if (bridge->funcs->post_disable) {  in drm_atomic_bridge_call_post_disable()
604 		bridge->funcs->post_disable(bridge);  in drm_atomic_bridge_call_post_disable()
609  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
624  * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
641 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_post_disable()
643 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_post_disable()
646 		if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) {  in drm_atomic_bridge_chain_post_disable()
649 			if (next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
658 				list_for_each_entry_from(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
660 					if (!next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
666 					if (list_is_last(&next->chain_node,  in drm_atomic_bridge_chain_post_disable()
667 							 &encoder->bridge_chain)) {  in drm_atomic_bridge_chain_post_disable()
674 				list_for_each_entry_from_reverse(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
697 	if (old_state && bridge->funcs->atomic_pre_enable) {  in drm_atomic_bridge_call_pre_enable()
706 		bridge->funcs->atomic_pre_enable(bridge, old_bridge_state);  in drm_atomic_bridge_call_pre_enable()
707 	} else if (bridge->funcs->pre_enable) {  in drm_atomic_bridge_call_pre_enable()
708 		bridge->funcs->pre_enable(bridge);  in drm_atomic_bridge_call_pre_enable()
713  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
727  * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
744 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_pre_enable()
746 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
747 		if (iter->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
751 							 &encoder->bridge_chain,  in drm_atomic_bridge_chain_pre_enable()
756 				if (!next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
765 			list_for_each_entry_from(next, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
781 		if (iter->pre_enable_prev_first)  in drm_atomic_bridge_chain_pre_enable()
792  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
811 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_enable()
812 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_enable()
813 		if (bridge->funcs->atomic_enable) {  in drm_atomic_bridge_chain_enable()
822 			bridge->funcs->atomic_enable(bridge, old_bridge_state);  in drm_atomic_bridge_chain_enable()
823 		} else if (bridge->funcs->enable) {  in drm_atomic_bridge_chain_enable()
824 			bridge->funcs->enable(bridge);  in drm_atomic_bridge_chain_enable()
834 	if (bridge->funcs->atomic_check) {  in drm_atomic_bridge_check()
838 		bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_check()
841 			return -EINVAL;  in drm_atomic_bridge_check()
843 		ret = bridge->funcs->atomic_check(bridge, bridge_state,  in drm_atomic_bridge_check()
847 	} else if (bridge->funcs->mode_fixup) {  in drm_atomic_bridge_check()
848 		if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,  in drm_atomic_bridge_check()
849 					       &crtc_state->adjusted_mode))  in drm_atomic_bridge_check()
850 			return -EINVAL;  in drm_atomic_bridge_check()
869 	cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in select_bus_fmt_recursive()
878 	if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {  in select_bus_fmt_recursive()
893 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;  in select_bus_fmt_recursive()
894 			cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
901 	 * If the driver implements ->atomic_get_input_bus_fmts() it  in select_bus_fmt_recursive()
905 		return -EINVAL;  in select_bus_fmt_recursive()
907 	in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,  in select_bus_fmt_recursive()
914 		return -ENOTSUPP;  in select_bus_fmt_recursive()
916 		return -ENOMEM;  in select_bus_fmt_recursive()
919 		cur_state->input_bus_cfg.format = in_bus_fmts[0];  in select_bus_fmt_recursive()
920 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
929 		if (ret != -ENOTSUPP)  in select_bus_fmt_recursive()
934 		cur_state->input_bus_cfg.format = in_bus_fmts[i];  in select_bus_fmt_recursive()
935 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
954  * support transcoding into a specific output format -ENOTSUPP is returned and
956  * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
981 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_select_bus_fmts()
982 	struct drm_encoder *encoder = bridge->encoder;  in drm_atomic_bridge_chain_select_bus_fmts()
989 	last_bridge = list_last_entry(&encoder->bridge_chain,  in drm_atomic_bridge_chain_select_bus_fmts()
991 	last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_chain_select_bus_fmts()
994 	if (last_bridge->funcs->atomic_get_output_bus_fmts) {  in drm_atomic_bridge_chain_select_bus_fmts()
995 		const struct drm_bridge_funcs *funcs = last_bridge->funcs;  in drm_atomic_bridge_chain_select_bus_fmts()
998 		 * If the driver implements ->atomic_get_output_bus_fmts() it  in drm_atomic_bridge_chain_select_bus_fmts()
1002 			return -EINVAL;  in drm_atomic_bridge_chain_select_bus_fmts()
1004 		out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,  in drm_atomic_bridge_chain_select_bus_fmts()
1010 			return -ENOTSUPP;  in drm_atomic_bridge_chain_select_bus_fmts()
1012 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1017 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1019 		if (conn->display_info.num_bus_formats &&  in drm_atomic_bridge_chain_select_bus_fmts()
1020 		    conn->display_info.bus_formats)  in drm_atomic_bridge_chain_select_bus_fmts()
1021 			out_bus_fmts[0] = conn->display_info.bus_formats[0];  in drm_atomic_bridge_chain_select_bus_fmts()
1029 		if (ret != -ENOTSUPP)  in drm_atomic_bridge_chain_select_bus_fmts()
1066 		output_flags = conn->display_info.bus_flags;  in drm_atomic_bridge_propagate_bus_flags()
1075 			output_flags = next_bridge_state->input_bus_cfg.flags;  in drm_atomic_bridge_propagate_bus_flags()
1078 	bridge_state->output_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1086 	bridge_state->input_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1090  * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1108 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_check()
1121 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_check()
1122 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_check()
1133 						      crtc_state->state);  in drm_atomic_bridge_chain_check()
1148  * drm_bridge_detect - check if anything is attached to the bridge output
1151  * If the bridge supports output detection, as reported by the
1157  * The detection status on success, or connector_status_unknown if the bridge
1158  * doesn't support output detection.
1162 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))  in drm_bridge_detect()
1165 	return bridge->funcs->detect(bridge);  in drm_bridge_detect()
1170  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1186 	if (!(bridge->ops & DRM_BRIDGE_OP_MODES))  in drm_bridge_get_modes()
1189 	return bridge->funcs->get_modes(bridge, connector);  in drm_bridge_get_modes()
1194  * drm_bridge_edid_read - read the EDID data of the connected display
1208 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))  in drm_bridge_edid_read()
1211 	return bridge->funcs->edid_read(bridge, connector);  in drm_bridge_edid_read()
1216  * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1218  * @cb: hot-plug detection callback
1219  * @data: data to be passed to the hot-plug detection callback
1226  * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1227  * bridge->ops. This function shall not be called when the flag is not set.
1229  * Only one hot plug detection callback can be registered at a time, it is an
1230  * error to call this function when hot plug detection is already enabled for
1238 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_enable()
1241 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1243 	if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))  in drm_bridge_hpd_enable()
1246 	bridge->hpd_cb = cb;  in drm_bridge_hpd_enable()
1247 	bridge->hpd_data = data;  in drm_bridge_hpd_enable()
1249 	if (bridge->funcs->hpd_enable)  in drm_bridge_hpd_enable()
1250 		bridge->funcs->hpd_enable(bridge);  in drm_bridge_hpd_enable()
1253 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1258  * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1262  * plug detection callback previously registered with drm_bridge_hpd_enable().
1266  * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1267  * bridge->ops. This function shall not be called when the flag is not set.
1271 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_disable()
1274 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1275 	if (bridge->funcs->hpd_disable)  in drm_bridge_hpd_disable()
1276 		bridge->funcs->hpd_disable(bridge);  in drm_bridge_hpd_disable()
1278 	bridge->hpd_cb = NULL;  in drm_bridge_hpd_disable()
1279 	bridge->hpd_data = NULL;  in drm_bridge_hpd_disable()
1280 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1285  * drm_bridge_hpd_notify - notify hot plug detection events
1290  * detect a change in the output status, when hot plug detection has been
1298 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1299 	if (bridge->hpd_cb)  in drm_bridge_hpd_notify()
1300 		bridge->hpd_cb(bridge->hpd_data, status);  in drm_bridge_hpd_notify()
1301 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1307  * of_drm_find_bridge - find the bridge corresponding to the device node in
1322 		if (bridge->of_node == np) {  in of_drm_find_bridge()