media: v4l2-fwnode: add initial connector parsing support

The patch adds the initial connector parsing code, so we can move from a
driver specific parsing code to a generic one. Currently only the
generic fields and the analog-connector specific fields are parsed. Parsing
the other connector specific fields can be added by a simple callbacks.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
[hverkuil-cisco@xs4all.nl: replace ; with break; in a empty case]
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 82 insertions, 0 deletions

diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h
index 6cf39d447b10..dd82d6d9764e 100644
--- a/include/media/v4l2-fwnode.h
+++ b/include/media/v4l2-fwnode.h
@@ -295,6 +295,66 @@ int v4l2_fwnode_parse_link(struct fwnode_handle *fwnode,
 void v4l2_fwnode_put_link(struct v4l2_fwnode_link *link);
 
 /**
+ * v4l2_fwnode_connector_free() - free the V4L2 connector acquired memory
+ * @connector: the V4L2 connector resources of which are to be released
+ *
+ * Free all allocated memory and put all links acquired by
+ * v4l2_fwnode_connector_parse() and v4l2_fwnode_connector_add_link().
+ *
+ * It is safe to call this function with NULL argument or on a V4L2 connector
+ * the parsing of which failed.
+ */
+void v4l2_fwnode_connector_free(struct v4l2_fwnode_connector *connector);
+
+/**
+ * v4l2_fwnode_connector_parse() - initialize the 'struct v4l2_fwnode_connector'
+ * @fwnode: pointer to the subdev endpoint's fwnode handle where the connector
+ *	    is connected to or to the connector endpoint fwnode handle.
+ * @connector: pointer to the V4L2 fwnode connector data structure
+ *
+ * Fill the &struct v4l2_fwnode_connector with the connector type, label and
+ * all &enum v4l2_connector_type specific connector data. The label is optional
+ * so it is set to %NULL if no one was found. The function initialize the links
+ * to zero. Adding links to the connector is done by calling
+ * v4l2_fwnode_connector_add_link().
+ *
+ * The memory allocated for the label must be freed when no longer needed.
+ * Freeing the memory is done by v4l2_fwnode_connector_free().
+ *
+ * Return:
+ * * %0 on success or a negative error code on failure:
+ * * %-EINVAL if @fwnode is invalid
+ * * %-ENOTCONN if connector type is unknown or connector device can't be found
+ */
+int v4l2_fwnode_connector_parse(struct fwnode_handle *fwnode,
+				struct v4l2_fwnode_connector *connector);
+
+/**
+ * v4l2_fwnode_connector_add_link - add a link between a connector node and
+ *				    a v4l2-subdev node.
+ * @fwnode: pointer to the subdev endpoint's fwnode handle where the connector
+ *          is connected to
+ * @connector: pointer to the V4L2 fwnode connector data structure
+ *
+ * Add a new &struct v4l2_connector_link link to the
+ * &struct v4l2_fwnode_connector connector links list. The link local_node
+ * points to the connector node, the remote_node to the host v4l2 (sub)dev.
+ *
+ * The taken references to remote_node and local_node must be dropped and the
+ * allocated memory must be freed when no longer needed. Both is done by calling
+ * v4l2_fwnode_connector_free().
+ *
+ * Return:
+ * * %0 on success or a negative error code on failure:
+ * * %-EINVAL if @fwnode or @connector is invalid or @connector type is unknown
+ * * %-ENOMEM on link memory allocation failure
+ * * %-ENOTCONN if remote connector device can't be found
+ * * %-ENOLINK if link parsing between v4l2 (sub)dev and connector fails
+ */
+int v4l2_fwnode_connector_add_link(struct fwnode_handle *fwnode,
+				   struct v4l2_fwnode_connector *connector);
+
+/**
  * typedef parse_endpoint_func - Driver's callback function to be called on
  *	each V4L2 fwnode endpoint.
  *
@@ -467,4 +527,26 @@ v4l2_async_register_fwnode_subdev(struct v4l2_subdev *sd,
 				  unsigned int num_ports,
 				  parse_endpoint_func parse_endpoint);
 
+/* Helper macros to access the connector links. */
+
+/** v4l2_connector_last_link - Helper macro to get the first
+ *                             &struct v4l2_fwnode_connector link
+ * @v4l2c: &struct v4l2_fwnode_connector owning the connector links
+ *
+ * This marco returns the first added &struct v4l2_connector_link connector
+ * link or @NULL if the connector has no links.
+ */
+#define v4l2_connector_first_link(v4l2c)				       \
+	list_first_entry_or_null(&(v4l2c)->links,			       \
+				 struct v4l2_connector_link, head)
+
+/** v4l2_connector_last_link - Helper macro to get the last
+ *                             &struct v4l2_fwnode_connector link
+ * @v4l2c: &struct v4l2_fwnode_connector owning the connector links
+ *
+ * This marco returns the last &struct v4l2_connector_link added connector link.
+ */
+#define v4l2_connector_last_link(v4l2c)					       \
+	list_last_entry(&(v4l2c)->links, struct v4l2_connector_link, head)
+
 #endif /* _V4L2_FWNODE_H */