[PATCHv3 1/6] drm: drm_bridge: add connector_attach/detach bridge ops

[Hans Verkuil]

Add bridge connector_attach/detach ops. These ops are called when a
bridge is attached or detached to a drm_connector. These ops can be
used to register and unregister an HDMI CEC adapter for a bridge that
supports CEC.

Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
---
 drivers/gpu/drm/drm_bridge_connector.c | 25 +++++++++++++++++++++++-
 include/drm/drm_bridge.h               | 27 ++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/drm_bridge_connector.c
index 791379816837..0676677badfe 100644
--- a/drivers/gpu/drm/drm_bridge_connector.c
+++ b/drivers/gpu/drm/drm_bridge_connector.c
@@ -203,6 +203,11 @@ static void drm_bridge_connector_destroy(struct drm_connector *connector)
 {
 	struct drm_bridge_connector *bridge_connector =
 		to_drm_bridge_connector(connector);
+	struct drm_bridge *bridge;
+
+	drm_for_each_bridge_in_chain(bridge_connector->encoder, bridge)
+		if (bridge->funcs->connector_detach)
+			bridge->funcs->connector_detach(bridge, connector);
 
 	if (bridge_connector->bridge_hpd) {
 		struct drm_bridge *hpd = bridge_connector->bridge_hpd;
@@ -318,6 +323,7 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 	struct i2c_adapter *ddc = NULL;
 	struct drm_bridge *bridge;
 	int connector_type;
+	int ret;
 
 	bridge_connector = kzalloc(sizeof(*bridge_connector), GFP_KERNEL);
 	if (!bridge_connector)
@@ -375,6 +381,23 @@ struct drm_connector *drm_bridge_connector_init(struct drm_device *drm,
 		connector->polled = DRM_CONNECTOR_POLL_CONNECT
 				  | DRM_CONNECTOR_POLL_DISCONNECT;
 
-	return connector;
+	ret = 0;
+	/* call connector_attach for all bridges */
+	drm_for_each_bridge_in_chain(encoder, bridge) {
+		if (!bridge->funcs->connector_attach)
+			continue;
+		ret = bridge->funcs->connector_attach(bridge, connector);
+		if (ret)
+			break;
+	}
+	if (!ret)
+		return connector;
+
+	/* on error, detach any previously successfully attached connectors */
+	list_for_each_entry_continue_reverse(bridge, &(encoder)->bridge_chain,
+					     chain_node)
+		if (bridge->funcs->connector_detach)
+			bridge->funcs->connector_detach(bridge, connector);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(drm_bridge_connector_init);
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 2195daa289d2..333fbc3a03e9 100644
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -629,6 +629,33 @@ struct drm_bridge_funcs {
 	 * the DRM_BRIDGE_OP_HPD flag in their &drm_bridge->ops.
 	 */
 	void (*hpd_disable)(struct drm_bridge *bridge);
+
+	/**
+	 * @connector_attach:
+	 *
+	 * This callback is invoked whenever our bridge is being attached to a
+	 * &drm_connector. This is where an HDMI CEC adapter can be registered.
+	 *
+	 * The @connector_attach callback is optional.
+	 *
+	 * RETURNS:
+	 *
+	 * Zero on success, error code on failure.
+	 */
+	int (*connector_attach)(struct drm_bridge *bridge,
+				struct drm_connector *conn);
+
+	/**
+	 * @connector_detach:
+	 *
+	 * This callback is invoked whenever our bridge is being detached from a
+	 * &drm_connector. This is where an HDMI CEC adapter can be
+	 * unregistered.
+	 *
+	 * The @connector_detach callback is optional.
+	 */
+	void (*connector_detach)(struct drm_bridge *bridge,
+				 struct drm_connector *conn);
 };
 
 /**
-- 
2.30.2