17  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
25 #include <linux/media-bus-format.h>
49  *     [ CRTC ---> ] Encoder ---> Bridge A ---> Bridge B
63  * DOC:	display driver integration
65  * Display drivers are responsible for linking encoders with the first bridge
84  * For display drivers that use the atomic helpers
87  * drm_atomic_helper_commit_modeset_disables() (either directly in hand-rolled
88  * commit check and commit tail handlers, or through the higher-level
95  * the bridge chain. Display drivers may use the drm_bridge_connector_init()
97  * connector-related operations exposed by the bridge (see the overview
109  * - The upstream driver doesn't use the component framework and isn't a
110  *   MIPI-DSI host. In this case, the bridge driver will probe at some
114  * - The upstream driver doesn't use the component framework, but is a
115  *   MIPI-DSI host. The bridge device uses the MIPI-DCS commands to be
117  *   display device and when it will probe it's assured that the display
118  *   device (and MIPI-DSI host) is present. The upstream driver will be
125  * - The upstream driver uses the component framework and is a MIPI-DSI
126  *   host. The bridge device uses the MIPI-DCS commands to be
130  * - The upstream driver uses the component framework and is a MIPI-DSI
138  * MIPI-DSI host driver case) is to split the operations like this:
140  * - The MIPI-DSI host driver must run mipi_dsi_host_register() in its
141  *   probe hook. It will make sure that the MIPI-DSI host sticks around,
144  * - In its probe hook, the bridge driver must try to find its MIPI-DSI
145  *   host, register as a MIPI-DSI device and attach the MIPI-DSI device
148  * - In its &struct mipi_dsi_host_ops.attach hook, the MIPI-DSI host can
154  * the bridge driver are functional and we can't have a deadlock-like
167  * must not be assumed that it is LP-11.
168  * pre_enable should initialise the PHY, set the data lanes to LP-11, and the
169  * clock lane to either LP-11 or HS depending on the mode_flag
173  * called before the DSI host. If the DSI peripheral requires LP-11 and/or
182  * should stop transmitting video, and the data lanes should return to the LP-11
201  * drm_bridge_add - add the given bridge to the global bridge list
207 	mutex_init(&bridge->hpd_mutex);  in drm_bridge_add()
210 	list_add_tail(&bridge->list, &bridge_list);  in drm_bridge_add()
221  * devm_drm_bridge_add - devm managed version of drm_bridge_add()
239  * drm_bridge_remove - remove the given bridge from the global bridge list
246 	list_del_init(&bridge->list);  in drm_bridge_remove()
249 	mutex_destroy(&bridge->hpd_mutex);  in drm_bridge_remove()
259 	state = bridge->funcs->atomic_duplicate_state(bridge);  in drm_bridge_atomic_duplicate_priv_state()
260 	return state ? &state->base : NULL;  in drm_bridge_atomic_duplicate_priv_state()
270 	bridge->funcs->atomic_destroy_state(bridge, state);  in drm_bridge_atomic_destroy_priv_state()
279  * drm_bridge_attach - attach the bridge to an encoder's chain
291  * If non-NULL the previous bridge must be already attached by a call to this
294  * Note that bridges attached to encoders are auto-detached during encoder
308 		return -EINVAL;  in drm_bridge_attach()
310 	if (previous && (!previous->dev || previous->encoder != encoder))  in drm_bridge_attach()
311 		return -EINVAL;  in drm_bridge_attach()
313 	if (bridge->dev)  in drm_bridge_attach()
314 		return -EBUSY;  in drm_bridge_attach()
316 	bridge->dev = encoder->dev;  in drm_bridge_attach()
317 	bridge->encoder = encoder;  in drm_bridge_attach()
320 		list_add(&bridge->chain_node, &previous->chain_node);  in drm_bridge_attach()
322 		list_add(&bridge->chain_node, &encoder->bridge_chain);  in drm_bridge_attach()
324 	if (bridge->funcs->attach) {  in drm_bridge_attach()
325 		ret = bridge->funcs->attach(bridge, flags);  in drm_bridge_attach()
330 	if (bridge->funcs->atomic_reset) {  in drm_bridge_attach()
333 		state = bridge->funcs->atomic_reset(bridge);  in drm_bridge_attach()
339 		drm_atomic_private_obj_init(bridge->dev, &bridge->base,  in drm_bridge_attach()
340 					    &state->base,  in drm_bridge_attach()
347 	if (bridge->funcs->detach)  in drm_bridge_attach()
348 		bridge->funcs->detach(bridge);  in drm_bridge_attach()
351 	bridge->dev = NULL;  in drm_bridge_attach()
352 	bridge->encoder = NULL;  in drm_bridge_attach()
353 	list_del(&bridge->chain_node);  in drm_bridge_attach()
357 		  bridge->of_node, encoder->name, ret);  in drm_bridge_attach()
360 		  encoder->name, ret);  in drm_bridge_attach()
372 	if (WARN_ON(!bridge->dev))  in drm_bridge_detach()
375 	if (bridge->funcs->atomic_reset)  in drm_bridge_detach()
376 		drm_atomic_private_obj_fini(&bridge->base);  in drm_bridge_detach()
378 	if (bridge->funcs->detach)  in drm_bridge_detach()
379 		bridge->funcs->detach(bridge);  in drm_bridge_detach()
381 	list_del(&bridge->chain_node);  in drm_bridge_detach()
382 	bridge->dev = NULL;  in drm_bridge_detach()
393  * - The encoder-related operations support control of the bridges in the
402  *   finer-grained control.
409  *   Mixing atomic and non-atomic versions of the operations is not supported.
411  * - The bus format negotiation operations
416  *   transparently for display drivers by the atomic modeset helpers. Only
419  *   encoder-related operations. This feature is not supported by the legacy
422  * - The connector-related operations support implementing a &drm_connector
433  *   an externally-implemented &drm_connector. Those operations are
437  *   implemented, display drivers shall create a &drm_connector instance for
441  *   Bridge drivers shall implement the connector-related operations for all
446  *   controller of the SoC. Support for the connector-related operations on the
453  *   flag will be set. Display drivers shall use the &drm_bridge.ops flags to
457  *   read-only memory.
461  *   connected-related bridge operations. Connector creation is then controlled
462  *   by the flags argument to the drm_bridge_attach() function. Display drivers
469  *   %DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is not set. New display drivers
475  * drm_bridge_chain_mode_fixup - fixup proposed mode for all bridges in the
498 	encoder = bridge->encoder;  in drm_bridge_chain_mode_fixup()
499 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_fixup()
500 		if (!bridge->funcs->mode_fixup)  in drm_bridge_chain_mode_fixup()
503 		if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))  in drm_bridge_chain_mode_fixup()
512  * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
515  * @info: display info against which the mode shall be validated
537 	encoder = bridge->encoder;  in drm_bridge_chain_mode_valid()
538 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_valid()
541 		if (!bridge->funcs->mode_valid)  in drm_bridge_chain_mode_valid()
544 		ret = bridge->funcs->mode_valid(bridge, info, mode);  in drm_bridge_chain_mode_valid()
554  * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
574 	encoder = bridge->encoder;  in drm_bridge_chain_mode_set()
575 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_set()
576 		if (bridge->funcs->mode_set)  in drm_bridge_chain_mode_set()
577 			bridge->funcs->mode_set(bridge, mode, adjusted_mode);  in drm_bridge_chain_mode_set()
583  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
603 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_disable()
604 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_disable()
605 		if (iter->funcs->atomic_disable) {  in drm_atomic_bridge_chain_disable()
614 			iter->funcs->atomic_disable(iter, old_bridge_state);  in drm_atomic_bridge_chain_disable()
615 		} else if (iter->funcs->disable) {  in drm_atomic_bridge_chain_disable()
616 			iter->funcs->disable(iter);  in drm_atomic_bridge_chain_disable()
628 	if (old_state && bridge->funcs->atomic_post_disable) {  in drm_atomic_bridge_call_post_disable()
637 		bridge->funcs->atomic_post_disable(bridge,  in drm_atomic_bridge_call_post_disable()
639 	} else if (bridge->funcs->post_disable) {  in drm_atomic_bridge_call_post_disable()
640 		bridge->funcs->post_disable(bridge);  in drm_atomic_bridge_call_post_disable()
645  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
670 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_post_disable()
672 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_post_disable()
675 		if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) {  in drm_atomic_bridge_chain_post_disable()
678 			if (next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
687 				list_for_each_entry_from(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
689 					if (next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
697 				list_for_each_entry_from_reverse(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
720 	if (old_state && bridge->funcs->atomic_pre_enable) {  in drm_atomic_bridge_call_pre_enable()
729 		bridge->funcs->atomic_pre_enable(bridge, old_bridge_state);  in drm_atomic_bridge_call_pre_enable()
730 	} else if (bridge->funcs->pre_enable) {  in drm_atomic_bridge_call_pre_enable()
731 		bridge->funcs->pre_enable(bridge);  in drm_atomic_bridge_call_pre_enable()
736  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
760 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_pre_enable()
762 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
763 		if (iter->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
767 							 &encoder->bridge_chain,  in drm_atomic_bridge_chain_pre_enable()
772 				if (!next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
781 			list_for_each_entry_from(next, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
797 		if (iter->pre_enable_prev_first)  in drm_atomic_bridge_chain_pre_enable()
808  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
827 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_enable()
828 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_enable()
829 		if (bridge->funcs->atomic_enable) {  in drm_atomic_bridge_chain_enable()
838 			bridge->funcs->atomic_enable(bridge, old_bridge_state);  in drm_atomic_bridge_chain_enable()
839 		} else if (bridge->funcs->enable) {  in drm_atomic_bridge_chain_enable()
840 			bridge->funcs->enable(bridge);  in drm_atomic_bridge_chain_enable()
850 	if (bridge->funcs->atomic_check) {  in drm_atomic_bridge_check()
854 		bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_check()
857 			return -EINVAL;  in drm_atomic_bridge_check()
859 		ret = bridge->funcs->atomic_check(bridge, bridge_state,  in drm_atomic_bridge_check()
863 	} else if (bridge->funcs->mode_fixup) {  in drm_atomic_bridge_check()
864 		if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,  in drm_atomic_bridge_check()
865 					       &crtc_state->adjusted_mode))  in drm_atomic_bridge_check()
866 			return -EINVAL;  in drm_atomic_bridge_check()
885 	cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in select_bus_fmt_recursive()
894 	if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {  in select_bus_fmt_recursive()
909 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;  in select_bus_fmt_recursive()
910 			cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
917 	 * If the driver implements ->atomic_get_input_bus_fmts() it  in select_bus_fmt_recursive()
921 		return -EINVAL;  in select_bus_fmt_recursive()
923 	in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,  in select_bus_fmt_recursive()
930 		return -ENOTSUPP;  in select_bus_fmt_recursive()
932 		return -ENOMEM;  in select_bus_fmt_recursive()
935 		cur_state->input_bus_cfg.format = in_bus_fmts[0];  in select_bus_fmt_recursive()
936 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
945 		if (ret != -ENOTSUPP)  in select_bus_fmt_recursive()
950 		cur_state->input_bus_cfg.format = in_bus_fmts[i];  in select_bus_fmt_recursive()
951 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
970  * support transcoding into a specific output format -ENOTSUPP is returned and
972  * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
997 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_select_bus_fmts()
998 	struct drm_encoder *encoder = bridge->encoder;  in drm_atomic_bridge_chain_select_bus_fmts()
1005 	last_bridge = list_last_entry(&encoder->bridge_chain,  in drm_atomic_bridge_chain_select_bus_fmts()
1007 	last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_chain_select_bus_fmts()
1010 	if (last_bridge->funcs->atomic_get_output_bus_fmts) {  in drm_atomic_bridge_chain_select_bus_fmts()
1011 		const struct drm_bridge_funcs *funcs = last_bridge->funcs;  in drm_atomic_bridge_chain_select_bus_fmts()
1014 		 * If the driver implements ->atomic_get_output_bus_fmts() it  in drm_atomic_bridge_chain_select_bus_fmts()
1018 			return -EINVAL;  in drm_atomic_bridge_chain_select_bus_fmts()
1020 		out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,  in drm_atomic_bridge_chain_select_bus_fmts()
1026 			return -ENOTSUPP;  in drm_atomic_bridge_chain_select_bus_fmts()
1028 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1033 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1035 		if (conn->display_info.num_bus_formats &&  in drm_atomic_bridge_chain_select_bus_fmts()
1036 		    conn->display_info.bus_formats)  in drm_atomic_bridge_chain_select_bus_fmts()
1037 			out_bus_fmts[0] = conn->display_info.bus_formats[0];  in drm_atomic_bridge_chain_select_bus_fmts()
1045 		if (ret != -ENOTSUPP)  in drm_atomic_bridge_chain_select_bus_fmts()
1082 		output_flags = conn->display_info.bus_flags;  in drm_atomic_bridge_propagate_bus_flags()
1091 			output_flags = next_bridge_state->input_bus_cfg.flags;  in drm_atomic_bridge_propagate_bus_flags()
1094 	bridge_state->output_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1102 	bridge_state->input_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1106  * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1124 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_check()
1137 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_check()
1138 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_check()
1149 						      crtc_state->state);  in drm_atomic_bridge_chain_check()
1164  * drm_bridge_detect - check if anything is attached to the bridge output
1178 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))  in drm_bridge_detect()
1181 	return bridge->funcs->detect(bridge);  in drm_bridge_detect()
1186  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1202 	if (!(bridge->ops & DRM_BRIDGE_OP_MODES))  in drm_bridge_get_modes()
1205 	return bridge->funcs->get_modes(bridge, connector);  in drm_bridge_get_modes()
1210  * drm_bridge_get_edid - get the EDID data of the connected display
1224 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))  in drm_bridge_get_edid()
1227 	return bridge->funcs->get_edid(bridge, connector);  in drm_bridge_get_edid()
1232  * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1234  * @cb: hot-plug detection callback
1235  * @data: data to be passed to the hot-plug detection callback
1243  * bridge->ops. This function shall not be called when the flag is not set.
1254 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_enable()
1257 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1259 	if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))  in drm_bridge_hpd_enable()
1262 	bridge->hpd_cb = cb;  in drm_bridge_hpd_enable()
1263 	bridge->hpd_data = data;  in drm_bridge_hpd_enable()
1265 	if (bridge->funcs->hpd_enable)  in drm_bridge_hpd_enable()
1266 		bridge->funcs->hpd_enable(bridge);  in drm_bridge_hpd_enable()
1269 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1274  * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1283  * bridge->ops. This function shall not be called when the flag is not set.
1287 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_disable()
1290 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1291 	if (bridge->funcs->hpd_disable)  in drm_bridge_hpd_disable()
1292 		bridge->funcs->hpd_disable(bridge);  in drm_bridge_hpd_disable()
1294 	bridge->hpd_cb = NULL;  in drm_bridge_hpd_disable()
1295 	bridge->hpd_data = NULL;  in drm_bridge_hpd_disable()
1296 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1301  * drm_bridge_hpd_notify - notify hot plug detection events
1314 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1315 	if (bridge->hpd_cb)  in drm_bridge_hpd_notify()
1316 		bridge->hpd_cb(bridge->hpd_data, status);  in drm_bridge_hpd_notify()
1317 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1323  * of_drm_find_bridge - find the bridge corresponding to the device node in
1338 		if (bridge->of_node == np) {  in of_drm_find_bridge()