Commit 05193dc3 authored by Boris Brezillon's avatar Boris Brezillon
Browse files

drm/bridge: Make the bridge chain a double-linked list 



So that each element in the chain can easily access its predecessor.
This will be needed to support bus format negotiation between elements
of the bridge chain.

Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-5-boris.brezillon@collabora.com
parent 35a61fe9

drivers/gpu/drm/drm_bridge.c

+111 −60
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ 
 * just provide additional hooks to get the desired output at the end of the

 * encoder chain.

 *

 * Bridges can also be chained up using the &drm_bridge.next pointer.

 * Bridges can also be chained up using the &drm_bridge.chain_node field.

 *

 * Both legacy CRTC helpers and the new atomic modeset helpers support bridges.

 */
@@ -128,20 +128,21 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, 
	bridge->dev = encoder->dev;

	bridge->encoder = encoder;



	if (previous)

		list_add(&bridge->chain_node, &previous->chain_node);

	else

		list_add(&bridge->chain_node, &encoder->bridge_chain);



	if (bridge->funcs->attach) {

		ret = bridge->funcs->attach(bridge);

		if (ret < 0) {

			list_del(&bridge->chain_node);

			bridge->dev = NULL;

			bridge->encoder = NULL;

			return ret;

		}

	}



	if (previous)

		previous->next = bridge;

	else

		encoder->bridge = bridge;



	return 0;

}

EXPORT_SYMBOL(drm_bridge_attach);
@@ -157,6 +158,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) 
	if (bridge->funcs->detach)

		bridge->funcs->detach(bridge);



	list_del(&bridge->chain_node);

	bridge->dev = NULL;

}
@@ -190,18 +192,21 @@ bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge, 
				 const struct drm_display_mode *mode,

				 struct drm_display_mode *adjusted_mode)

{

	bool ret = true;

	struct drm_encoder *encoder;



	if (!bridge)

		return true;



	if (bridge->funcs->mode_fixup)

		ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode);

	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (!bridge->funcs->mode_fixup)

			continue;



	ret = ret && drm_bridge_chain_mode_fixup(bridge->next, mode,

						 adjusted_mode);

		if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode))

			return false;

	}



	return ret;

	return true;

}

EXPORT_SYMBOL(drm_bridge_chain_mode_fixup);
@@ -224,18 +229,24 @@ enum drm_mode_status 
drm_bridge_chain_mode_valid(struct drm_bridge *bridge,

			    const struct drm_display_mode *mode)

{

	enum drm_mode_status ret = MODE_OK;

	struct drm_encoder *encoder;



	if (!bridge)

		return ret;

		return MODE_OK;



	if (bridge->funcs->mode_valid)

		ret = bridge->funcs->mode_valid(bridge, mode);

	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		enum drm_mode_status ret;



		if (!bridge->funcs->mode_valid)

			continue;



		ret = bridge->funcs->mode_valid(bridge, mode);

		if (ret != MODE_OK)

			return ret;

	}



	return drm_bridge_chain_mode_valid(bridge->next, mode);

	return MODE_OK;

}

EXPORT_SYMBOL(drm_bridge_chain_mode_valid);
@@ -251,13 +262,20 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_valid); 
 */

void drm_bridge_chain_disable(struct drm_bridge *bridge)

{

	struct drm_encoder *encoder;

	struct drm_bridge *iter;



	if (!bridge)

		return;



	drm_bridge_chain_disable(bridge->next);

	encoder = bridge->encoder;

	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {

		if (iter->funcs->disable)

			iter->funcs->disable(iter);



	if (bridge->funcs->disable)

		bridge->funcs->disable(bridge);

		if (iter == bridge)

			break;

	}

}

EXPORT_SYMBOL(drm_bridge_chain_disable);
@@ -274,13 +292,16 @@ EXPORT_SYMBOL(drm_bridge_chain_disable); 
 */

void drm_bridge_chain_post_disable(struct drm_bridge *bridge)

{

	struct drm_encoder *encoder;



	if (!bridge)

		return;



	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (bridge->funcs->post_disable)

			bridge->funcs->post_disable(bridge);



	drm_bridge_chain_post_disable(bridge->next);

	}

}

EXPORT_SYMBOL(drm_bridge_chain_post_disable);
@@ -300,13 +321,16 @@ void drm_bridge_chain_mode_set(struct drm_bridge *bridge, 
			       const struct drm_display_mode *mode,

			       const struct drm_display_mode *adjusted_mode)

{

	struct drm_encoder *encoder;



	if (!bridge)

		return;



	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (bridge->funcs->mode_set)

			bridge->funcs->mode_set(bridge, mode, adjusted_mode);



	drm_bridge_chain_mode_set(bridge->next, mode, adjusted_mode);

	}

}

EXPORT_SYMBOL(drm_bridge_chain_mode_set);
@@ -323,13 +347,17 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_set); 
 */

void drm_bridge_chain_pre_enable(struct drm_bridge *bridge)

{

	struct drm_encoder *encoder;

	struct drm_bridge *iter;



	if (!bridge)

		return;



	drm_bridge_chain_pre_enable(bridge->next);



	if (bridge->funcs->pre_enable)

		bridge->funcs->pre_enable(bridge);

	encoder = bridge->encoder;

	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {

		if (iter->funcs->pre_enable)

			iter->funcs->pre_enable(iter);

	}

}

EXPORT_SYMBOL(drm_bridge_chain_pre_enable);
@@ -345,13 +373,16 @@ EXPORT_SYMBOL(drm_bridge_chain_pre_enable); 
 */

void drm_bridge_chain_enable(struct drm_bridge *bridge)

{

	struct drm_encoder *encoder;



	if (!bridge)

		return;



	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (bridge->funcs->enable)

			bridge->funcs->enable(bridge);



	drm_bridge_chain_enable(bridge->next);

	}

}

EXPORT_SYMBOL(drm_bridge_chain_enable);
@@ -370,15 +401,22 @@ EXPORT_SYMBOL(drm_bridge_chain_enable); 
void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge,

				     struct drm_atomic_state *state)

{

	struct drm_encoder *encoder;

	struct drm_bridge *iter;



	if (!bridge)

		return;



	drm_atomic_bridge_chain_disable(bridge->next, state);

	encoder = bridge->encoder;

	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {

		if (iter->funcs->atomic_disable)

			iter->funcs->atomic_disable(iter, state);

		else if (iter->funcs->disable)

			iter->funcs->disable(iter);



	if (bridge->funcs->atomic_disable)

		bridge->funcs->atomic_disable(bridge, state);

	else if (bridge->funcs->disable)

		bridge->funcs->disable(bridge);

		if (iter == bridge)

			break;

	}

}

EXPORT_SYMBOL(drm_atomic_bridge_chain_disable);
@@ -398,15 +436,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_disable); 
void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,

					  struct drm_atomic_state *state)

{

	struct drm_encoder *encoder;



	if (!bridge)

		return;



	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (bridge->funcs->atomic_post_disable)

			bridge->funcs->atomic_post_disable(bridge, state);

		else if (bridge->funcs->post_disable)

			bridge->funcs->post_disable(bridge);



	drm_atomic_bridge_chain_post_disable(bridge->next, state);

	}

}

EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable);
@@ -426,15 +467,22 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable); 
void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,

					struct drm_atomic_state *state)

{

	struct drm_encoder *encoder;

	struct drm_bridge *iter;



	if (!bridge)

		return;



	drm_atomic_bridge_chain_pre_enable(bridge->next, state);

	encoder = bridge->encoder;

	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {

		if (iter->funcs->atomic_pre_enable)

			iter->funcs->atomic_pre_enable(iter, state);

		else if (iter->funcs->pre_enable)

			iter->funcs->pre_enable(iter);



	if (bridge->funcs->atomic_pre_enable)

		bridge->funcs->atomic_pre_enable(bridge, state);

	else if (bridge->funcs->pre_enable)

		bridge->funcs->pre_enable(bridge);

		if (iter == bridge)

			break;

	}

}

EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable);
@@ -453,15 +501,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); 
void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge,

				    struct drm_atomic_state *state)

{

	struct drm_encoder *encoder;



	if (!bridge)

		return;



	encoder = bridge->encoder;

	list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) {

		if (bridge->funcs->atomic_enable)

			bridge->funcs->atomic_enable(bridge, state);

		else if (bridge->funcs->enable)

			bridge->funcs->enable(bridge);



	drm_atomic_bridge_chain_enable(bridge->next, state);

	}

}

EXPORT_SYMBOL(drm_atomic_bridge_chain_enable);

drivers/gpu/drm/drm_encoder.c

+5 −11
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ int drm_encoder_init(struct drm_device *dev, 
		goto out_put;

	}



	INIT_LIST_HEAD(&encoder->bridge_chain);

	list_add_tail(&encoder->head, &dev->mode_config.encoder_list);

	encoder->index = dev->mode_config.num_encoder++;
@@ -160,23 +161,16 @@ EXPORT_SYMBOL(drm_encoder_init); 
void drm_encoder_cleanup(struct drm_encoder *encoder)

{

	struct drm_device *dev = encoder->dev;

	struct drm_bridge *bridge, *next;



	/* Note that the encoder_list is considered to be static; should we

	 * remove the drm_encoder at runtime we would have to decrement all

	 * the indices on the drm_encoder after us in the encoder_list.

	 */



	if (encoder->bridge) {

		struct drm_bridge *bridge;

		struct drm_bridge *next;



		bridge = drm_bridge_chain_get_first_bridge(encoder);

		while (bridge) {

			next = drm_bridge_get_next_bridge(bridge);

	list_for_each_entry_safe(bridge, next, &encoder->bridge_chain,

				 chain_node)

		drm_bridge_detach(bridge);

			bridge = next;

		}

	}



	drm_mode_object_unregister(dev, &encoder->base);

	kfree(encoder->name);

drivers/gpu/drm/exynos/exynos_drm_dsi.c

+4 −1
Original line number Diff line number Diff line
@@ -255,6 +255,7 @@ struct exynos_dsi { 
	struct mipi_dsi_host dsi_host;

	struct drm_connector connector;

	struct drm_panel *panel;

	struct list_head bridge_chain;

	struct drm_bridge *out_bridge;

	struct device *dev;
@@ -1522,7 +1523,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host, 
	if (out_bridge) {

		drm_bridge_attach(encoder, out_bridge, NULL);

		dsi->out_bridge = out_bridge;

		encoder->bridge = NULL;

		list_splice(&encoder->bridge_chain, &dsi->bridge_chain);

	} else {

		int ret = exynos_dsi_create_connector(encoder);
@@ -1588,6 +1589,7 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host, 
		if (dsi->out_bridge->funcs->detach)

			dsi->out_bridge->funcs->detach(dsi->out_bridge);

		dsi->out_bridge = NULL;

		INIT_LIST_HEAD(&dsi->bridge_chain);

	}



	if (drm->mode_config.poll_enabled)
@@ -1735,6 +1737,7 @@ static int exynos_dsi_probe(struct platform_device *pdev) 
	init_completion(&dsi->completed);

	spin_lock_init(&dsi->transfer_lock);

	INIT_LIST_HEAD(&dsi->transfer_list);

	INIT_LIST_HEAD(&dsi->bridge_chain);



	dsi->dsi_host.ops = &exynos_dsi_ops;

	dsi->dsi_host.dev = dev;

drivers/gpu/drm/vc4/vc4_dsi.c

+9 −1
Original line number Diff line number Diff line
@@ -499,6 +499,7 @@ struct vc4_dsi { 
	struct mipi_dsi_host dsi_host;

	struct drm_encoder *encoder;

	struct drm_bridge *bridge;

	struct list_head bridge_chain;



	void __iomem *regs;
@@ -1460,6 +1461,8 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data) 
				       GFP_KERNEL);

	if (!vc4_dsi_encoder)

		return -ENOMEM;



	INIT_LIST_HEAD(&dsi->bridge_chain);

	vc4_dsi_encoder->base.type = VC4_ENCODER_TYPE_DSI1;

	vc4_dsi_encoder->dsi = dsi;

	dsi->encoder = &vc4_dsi_encoder->base.base;
@@ -1610,7 +1613,7 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data) 
	 * from our driver, since we need to sequence them within the

	 * encoder's enable/disable paths.

	 */

	dsi->encoder->bridge = NULL;

	list_splice(&dsi->encoder->bridge_chain, &dsi->bridge_chain);



	if (dsi->port == 0)

		vc4_debugfs_add_regset32(drm, "dsi0_regs", &dsi->regset);
@@ -1632,6 +1635,11 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master, 
	if (dsi->bridge)

		pm_runtime_disable(dev);



	/*

	 * Restore the bridge_chain so the bridge detach procedure can happen

	 * normally.

	 */

	list_splice(&dsi->bridge_chain, &dsi->encoder->bridge_chain);

	vc4_dsi_encoder_destroy(dsi->encoder);



	if (dsi->port == 1)

include/drm/drm_bridge.h

+8 −4
Original line number Diff line number Diff line
@@ -384,8 +384,8 @@ struct drm_bridge { 
	struct drm_device *dev;

	/** @encoder: encoder to which this bridge is connected */

	struct drm_encoder *encoder;

	/** @next: the next bridge in the encoder chain */

	struct drm_bridge *next;

	/** @chain_node: used to form a bridge chain */

	struct list_head chain_node;

#ifdef CONFIG_OF

	/** @of_node: device node pointer to the bridge */

	struct device_node *of_node;
@@ -420,7 +420,10 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, 
static inline struct drm_bridge *

drm_bridge_get_next_bridge(struct drm_bridge *bridge)

{

	return bridge->next;

	if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain))

		return NULL;



	return list_next_entry(bridge, chain_node);

}



/**
@@ -434,7 +437,8 @@ drm_bridge_get_next_bridge(struct drm_bridge *bridge) 
static inline struct drm_bridge *

drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder)

{

	return encoder->bridge;

	return list_first_entry_or_null(&encoder->bridge_chain,

					struct drm_bridge, chain_node);

}



bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge,

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