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
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
183  * should stop transmitting video, and the data lanes should return to the LP-11
202  * drm_bridge_add - add the given bridge to the global bridge list
208 	mutex_init(&bridge->hpd_mutex);  in drm_bridge_add()
210 	if (bridge->ops & DRM_BRIDGE_OP_HDMI)  in drm_bridge_add()
211 		bridge->ycbcr_420_allowed = !!(bridge->supported_formats &  in drm_bridge_add()
215 	list_add_tail(&bridge->list, &bridge_list);  in drm_bridge_add()
226  * devm_drm_bridge_add - devm managed version of drm_bridge_add()
244  * drm_bridge_remove - remove the given bridge from the global bridge list
251 	list_del_init(&bridge->list);  in drm_bridge_remove()
254 	mutex_destroy(&bridge->hpd_mutex);  in drm_bridge_remove()
264 	state = bridge->funcs->atomic_duplicate_state(bridge);  in drm_bridge_atomic_duplicate_priv_state()
265 	return state ? &state->base : NULL;  in drm_bridge_atomic_duplicate_priv_state()
275 	bridge->funcs->atomic_destroy_state(bridge, state);  in drm_bridge_atomic_destroy_priv_state()
284  * drm_bridge_attach - attach the bridge to an encoder's chain
296  * If non-NULL the previous bridge must be already attached by a call to this
299  * Note that bridges attached to encoders are auto-detached during encoder
313 		return -EINVAL;  in drm_bridge_attach()
315 	if (previous && (!previous->dev || previous->encoder != encoder))  in drm_bridge_attach()
316 		return -EINVAL;  in drm_bridge_attach()
318 	if (bridge->dev)  in drm_bridge_attach()
319 		return -EBUSY;  in drm_bridge_attach()
321 	bridge->dev = encoder->dev;  in drm_bridge_attach()
322 	bridge->encoder = encoder;  in drm_bridge_attach()
325 		list_add(&bridge->chain_node, &previous->chain_node);  in drm_bridge_attach()
327 		list_add(&bridge->chain_node, &encoder->bridge_chain);  in drm_bridge_attach()
329 	if (bridge->funcs->attach) {  in drm_bridge_attach()
330 		ret = bridge->funcs->attach(bridge, flags);  in drm_bridge_attach()
335 	if (bridge->funcs->atomic_reset) {  in drm_bridge_attach()
338 		state = bridge->funcs->atomic_reset(bridge);  in drm_bridge_attach()
344 		drm_atomic_private_obj_init(bridge->dev, &bridge->base,  in drm_bridge_attach()
345 					    &state->base,  in drm_bridge_attach()
352 	if (bridge->funcs->detach)  in drm_bridge_attach()
353 		bridge->funcs->detach(bridge);  in drm_bridge_attach()
356 	bridge->dev = NULL;  in drm_bridge_attach()
357 	bridge->encoder = NULL;  in drm_bridge_attach()
358 	list_del(&bridge->chain_node);  in drm_bridge_attach()
360 	if (ret != -EPROBE_DEFER)  in drm_bridge_attach()
362 			  bridge->of_node, encoder->name, ret);  in drm_bridge_attach()
364 		dev_err_probe(encoder->dev->dev, -EPROBE_DEFER,  in drm_bridge_attach()
366 			      bridge->of_node, encoder->name);  in drm_bridge_attach()
377 	if (WARN_ON(!bridge->dev))  in drm_bridge_detach()
380 	if (bridge->funcs->atomic_reset)  in drm_bridge_detach()
381 		drm_atomic_private_obj_fini(&bridge->base);  in drm_bridge_detach()
383 	if (bridge->funcs->detach)  in drm_bridge_detach()
384 		bridge->funcs->detach(bridge);  in drm_bridge_detach()
386 	list_del(&bridge->chain_node);  in drm_bridge_detach()
387 	bridge->dev = NULL;  in drm_bridge_detach()
398  * - The encoder-related operations support control of the bridges in the
407  *   finer-grained control.
414  *   Mixing atomic and non-atomic versions of the operations is not supported.
416  * - The bus format negotiation operations
424  *   encoder-related operations. This feature is not supported by the legacy
427  * - The connector-related operations support implementing a &drm_connector
438  *   an externally-implemented &drm_connector. Those operations are
446  *   Bridge drivers shall implement the connector-related operations for all
451  *   controller of the SoC. Support for the connector-related operations on the
462  *   read-only memory.
466  *   connected-related bridge operations. Connector creation is then controlled
480  * drm_bridge_chain_mode_valid - validate the mode against all bridges in the
505 	encoder = bridge->encoder;  in drm_bridge_chain_mode_valid()
506 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_valid()
509 		if (!bridge->funcs->mode_valid)  in drm_bridge_chain_mode_valid()
512 		ret = bridge->funcs->mode_valid(bridge, info, mode);  in drm_bridge_chain_mode_valid()
522  * drm_bridge_chain_mode_set - set proposed mode for all bridges in the
542 	encoder = bridge->encoder;  in drm_bridge_chain_mode_set()
543 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_bridge_chain_mode_set()
544 		if (bridge->funcs->mode_set)  in drm_bridge_chain_mode_set()
545 			bridge->funcs->mode_set(bridge, mode, adjusted_mode);  in drm_bridge_chain_mode_set()
551  * drm_atomic_bridge_chain_disable - disables all bridges in the encoder chain
571 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_disable()
572 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_disable()
573 		if (iter->funcs->atomic_disable) {  in drm_atomic_bridge_chain_disable()
582 			iter->funcs->atomic_disable(iter, old_bridge_state);  in drm_atomic_bridge_chain_disable()
583 		} else if (iter->funcs->disable) {  in drm_atomic_bridge_chain_disable()
584 			iter->funcs->disable(iter);  in drm_atomic_bridge_chain_disable()
596 	if (old_state && bridge->funcs->atomic_post_disable) {  in drm_atomic_bridge_call_post_disable()
605 		bridge->funcs->atomic_post_disable(bridge,  in drm_atomic_bridge_call_post_disable()
607 	} else if (bridge->funcs->post_disable) {  in drm_atomic_bridge_call_post_disable()
608 		bridge->funcs->post_disable(bridge);  in drm_atomic_bridge_call_post_disable()
613  * drm_atomic_bridge_chain_post_disable - cleans up after disabling all bridges
628  * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
645 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_post_disable()
647 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_post_disable()
650 		if (!list_is_last(&bridge->chain_node, &encoder->bridge_chain)) {  in drm_atomic_bridge_chain_post_disable()
653 			if (next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
662 				list_for_each_entry_from(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
664 					if (!next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_post_disable()
670 					if (list_is_last(&next->chain_node,  in drm_atomic_bridge_chain_post_disable()
671 							 &encoder->bridge_chain)) {  in drm_atomic_bridge_chain_post_disable()
678 				list_for_each_entry_from_reverse(next, &encoder->bridge_chain,  in drm_atomic_bridge_chain_post_disable()
701 	if (old_state && bridge->funcs->atomic_pre_enable) {  in drm_atomic_bridge_call_pre_enable()
710 		bridge->funcs->atomic_pre_enable(bridge, old_bridge_state);  in drm_atomic_bridge_call_pre_enable()
711 	} else if (bridge->funcs->pre_enable) {  in drm_atomic_bridge_call_pre_enable()
712 		bridge->funcs->pre_enable(bridge);  in drm_atomic_bridge_call_pre_enable()
717  * drm_atomic_bridge_chain_pre_enable - prepares for enabling all bridges in
731  * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E
748 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_pre_enable()
750 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
751 		if (iter->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
755 							 &encoder->bridge_chain,  in drm_atomic_bridge_chain_pre_enable()
760 				if (!next->pre_enable_prev_first) {  in drm_atomic_bridge_chain_pre_enable()
769 			list_for_each_entry_from(next, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_pre_enable()
785 		if (iter->pre_enable_prev_first)  in drm_atomic_bridge_chain_pre_enable()
796  * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain
815 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_enable()
816 	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_enable()
817 		if (bridge->funcs->atomic_enable) {  in drm_atomic_bridge_chain_enable()
826 			bridge->funcs->atomic_enable(bridge, old_bridge_state);  in drm_atomic_bridge_chain_enable()
827 		} else if (bridge->funcs->enable) {  in drm_atomic_bridge_chain_enable()
828 			bridge->funcs->enable(bridge);  in drm_atomic_bridge_chain_enable()
838 	if (bridge->funcs->atomic_check) {  in drm_atomic_bridge_check()
842 		bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_check()
845 			return -EINVAL;  in drm_atomic_bridge_check()
847 		ret = bridge->funcs->atomic_check(bridge, bridge_state,  in drm_atomic_bridge_check()
851 	} else if (bridge->funcs->mode_fixup) {  in drm_atomic_bridge_check()
852 		if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode,  in drm_atomic_bridge_check()
853 					       &crtc_state->adjusted_mode))  in drm_atomic_bridge_check()
854 			return -EINVAL;  in drm_atomic_bridge_check()
873 	cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in select_bus_fmt_recursive()
882 	if (!cur_bridge->funcs->atomic_get_input_bus_fmts) {  in select_bus_fmt_recursive()
897 			cur_state->input_bus_cfg.format = MEDIA_BUS_FMT_FIXED;  in select_bus_fmt_recursive()
898 			cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
905 	 * If the driver implements ->atomic_get_input_bus_fmts() it  in select_bus_fmt_recursive()
909 		return -EINVAL;  in select_bus_fmt_recursive()
911 	in_bus_fmts = cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge,  in select_bus_fmt_recursive()
918 		return -ENOTSUPP;  in select_bus_fmt_recursive()
920 		return -ENOMEM;  in select_bus_fmt_recursive()
923 		cur_state->input_bus_cfg.format = in_bus_fmts[0];  in select_bus_fmt_recursive()
924 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
933 		if (ret != -ENOTSUPP)  in select_bus_fmt_recursive()
938 		cur_state->input_bus_cfg.format = in_bus_fmts[i];  in select_bus_fmt_recursive()
939 		cur_state->output_bus_cfg.format = out_bus_fmt;  in select_bus_fmt_recursive()
958  * support transcoding into a specific output format -ENOTSUPP is returned and
960  * combinations worked, -ENOTSUPP is returned and the atomic modeset will fail.
985 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_select_bus_fmts()
986 	struct drm_encoder *encoder = bridge->encoder;  in drm_atomic_bridge_chain_select_bus_fmts()
993 	last_bridge = list_last_entry(&encoder->bridge_chain,  in drm_atomic_bridge_chain_select_bus_fmts()
995 	last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state,  in drm_atomic_bridge_chain_select_bus_fmts()
998 	if (last_bridge->funcs->atomic_get_output_bus_fmts) {  in drm_atomic_bridge_chain_select_bus_fmts()
999 		const struct drm_bridge_funcs *funcs = last_bridge->funcs;  in drm_atomic_bridge_chain_select_bus_fmts()
1002 		 * If the driver implements ->atomic_get_output_bus_fmts() it  in drm_atomic_bridge_chain_select_bus_fmts()
1006 			return -EINVAL;  in drm_atomic_bridge_chain_select_bus_fmts()
1008 		out_bus_fmts = funcs->atomic_get_output_bus_fmts(last_bridge,  in drm_atomic_bridge_chain_select_bus_fmts()
1014 			return -ENOTSUPP;  in drm_atomic_bridge_chain_select_bus_fmts()
1016 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1021 			return -ENOMEM;  in drm_atomic_bridge_chain_select_bus_fmts()
1023 		if (conn->display_info.num_bus_formats &&  in drm_atomic_bridge_chain_select_bus_fmts()
1024 		    conn->display_info.bus_formats)  in drm_atomic_bridge_chain_select_bus_fmts()
1025 			out_bus_fmts[0] = conn->display_info.bus_formats[0];  in drm_atomic_bridge_chain_select_bus_fmts()
1033 		if (ret != -ENOTSUPP)  in drm_atomic_bridge_chain_select_bus_fmts()
1070 		output_flags = conn->display_info.bus_flags;  in drm_atomic_bridge_propagate_bus_flags()
1079 			output_flags = next_bridge_state->input_bus_cfg.flags;  in drm_atomic_bridge_propagate_bus_flags()
1082 	bridge_state->output_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1090 	bridge_state->input_bus_cfg.flags = output_flags;  in drm_atomic_bridge_propagate_bus_flags()
1094  * drm_atomic_bridge_chain_check() - Do an atomic check on the bridge chain
1112 	struct drm_connector *conn = conn_state->connector;  in drm_atomic_bridge_chain_check()
1125 	encoder = bridge->encoder;  in drm_atomic_bridge_chain_check()
1126 	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {  in drm_atomic_bridge_chain_check()
1137 						      crtc_state->state);  in drm_atomic_bridge_chain_check()
1152  * drm_bridge_detect - check if anything is attached to the bridge output
1166 	if (!(bridge->ops & DRM_BRIDGE_OP_DETECT))  in drm_bridge_detect()
1169 	return bridge->funcs->detect(bridge);  in drm_bridge_detect()
1174  * drm_bridge_get_modes - fill all modes currently valid for the sink into the
1190 	if (!(bridge->ops & DRM_BRIDGE_OP_MODES))  in drm_bridge_get_modes()
1193 	return bridge->funcs->get_modes(bridge, connector);  in drm_bridge_get_modes()
1198  * drm_bridge_edid_read - read the EDID data of the connected display
1212 	if (!(bridge->ops & DRM_BRIDGE_OP_EDID))  in drm_bridge_edid_read()
1215 	return bridge->funcs->edid_read(bridge, connector);  in drm_bridge_edid_read()
1220  * drm_bridge_hpd_enable - enable hot plug detection for the bridge
1222  * @cb: hot-plug detection callback
1223  * @data: data to be passed to the hot-plug detection callback
1226  * and @data as hot plug notification callback. From now on the @cb will be
1228  * until hot plug notification gets disabled with drm_bridge_hpd_disable().
1230  * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1231  * bridge->ops. This function shall not be called when the flag is not set.
1233  * Only one hot plug detection callback can be registered at a time, it is an
1234  * error to call this function when hot plug detection is already enabled for
1242 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_enable()
1245 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1247 	if (WARN(bridge->hpd_cb, "Hot plug detection already enabled\n"))  in drm_bridge_hpd_enable()
1250 	bridge->hpd_cb = cb;  in drm_bridge_hpd_enable()
1251 	bridge->hpd_data = data;  in drm_bridge_hpd_enable()
1253 	if (bridge->funcs->hpd_enable)  in drm_bridge_hpd_enable()
1254 		bridge->funcs->hpd_enable(bridge);  in drm_bridge_hpd_enable()
1257 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_enable()
1262  * drm_bridge_hpd_disable - disable hot plug detection for the bridge
1265  * Call &drm_bridge_funcs.hpd_disable if implemented and unregister the hot
1266  * plug detection callback previously registered with drm_bridge_hpd_enable().
1270  * Hot plug detection is supported only if the DRM_BRIDGE_OP_HPD flag is set in
1271  * bridge->ops. This function shall not be called when the flag is not set.
1275 	if (!(bridge->ops & DRM_BRIDGE_OP_HPD))  in drm_bridge_hpd_disable()
1278 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1279 	if (bridge->funcs->hpd_disable)  in drm_bridge_hpd_disable()
1280 		bridge->funcs->hpd_disable(bridge);  in drm_bridge_hpd_disable()
1282 	bridge->hpd_cb = NULL;  in drm_bridge_hpd_disable()
1283 	bridge->hpd_data = NULL;  in drm_bridge_hpd_disable()
1284 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_disable()
1289  * drm_bridge_hpd_notify - notify hot plug detection events
1293  * Bridge drivers shall call this function to report hot plug events when they
1294  * detect a change in the output status, when hot plug detection has been
1302 	mutex_lock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1303 	if (bridge->hpd_cb)  in drm_bridge_hpd_notify()
1304 		bridge->hpd_cb(bridge->hpd_data, status);  in drm_bridge_hpd_notify()
1305 	mutex_unlock(&bridge->hpd_mutex);  in drm_bridge_hpd_notify()
1311  * of_drm_find_bridge - find the bridge corresponding to the device node in
1326 		if (bridge->of_node == np) {  in of_drm_find_bridge()