The function fills a link data structure with the device node and port
number at both the local and remote ends of a link defined by one of its
endpoint nodes.
Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-of.c | 61 +++++++++++++++++++++++++++++++++++++++
include/media/v4l2-of.h | 27 +++++++++++++++++
2 files changed, 88 insertions(+)
Cc: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
index b4ed9a9..c473479 100644
--- a/drivers/media/v4l2-core/v4l2-of.c
+++ b/drivers/media/v4l2-core/v4l2-of.c
@@ -142,3 +142,64 @@ int v4l2_of_parse_endpoint(const struct device_node *node,
return 0;
}
EXPORT_SYMBOL(v4l2_of_parse_endpoint);
+
+/**
+ * v4l2_of_parse_link() - parse a link between two endpoints
+ * @node: pointer to the endpoint at the local end of the link
+ * @link: pointer to the V4L2 OF link data structure
+ *
+ * Fill the link structure with the local and remote nodes and port numbers.
+ * The local_node and remote_node fields are set to point to the local and
+ * remote port parent nodes respectively (the port parent node being the parent
+ * node of the port node if that node isn't a 'ports' node, or the grand-parent
+ * node of the port node otherwise).
+ *
+ * A reference is taken to both the local and remote nodes, the caller must use
+ * v4l2_of_put_link() to drop the references when done with the link.
+ *
+ * Return: 0 on success, or -ENOLINK if the remote endpoint can't be found.
+ */
+int v4l2_of_parse_link(const struct device_node *node,
+ struct v4l2_of_link *link)
+{
+ struct device_node *np;
+
+ memset(link, 0, sizeof(*link));
+
+ np = of_get_parent(node);
+ of_property_read_u32(np, "reg", &link->local_port);
+ np = of_get_next_parent(np);
+ if (of_node_cmp(np->name, "ports") == 0)
+ np = of_get_next_parent(np);
+ link->local_node = np;
+
+ np = of_parse_phandle(node, "remote-endpoint", 0);
+ if (!np) {
+ of_node_put(link->local_node);
+ return -ENOLINK;
+ }
+
+ np = of_get_parent(np);
+ of_property_read_u32(np, "reg", &link->remote_port);
+ np = of_get_next_parent(np);
+ if (of_node_cmp(np->name, "ports") == 0)
+ np = of_get_next_parent(np);
+ link->remote_node = np;
+
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_of_parse_link);
+
+/**
+ * v4l2_of_put_link() - drop references to nodes in a link
+ * @link: pointer to the V4L2 OF link data structure
+ *
+ * Drop references to the local and remote nodes in the link. This function must
+ * be called on every link parsed with v4l2_of_parse_link().
+ */
+void v4l2_of_put_link(struct v4l2_of_link *link)
+{
+ of_node_put(link->local_node);
+ of_node_put(link->remote_node);
+}
+EXPORT_SYMBOL(v4l2_of_put_link);
diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h
index 70fa7b7..078846d 100644
--- a/include/media/v4l2-of.h
+++ b/include/media/v4l2-of.h
@@ -66,9 +66,26 @@ struct v4l2_of_endpoint {
struct list_head head;
};
+/**
+ * struct v4l2_of_link - a link between two endpoints
+ * @local_node: pointer to device_node of this endpoint
+ * @local_port: identifier of the port this endpoint belongs to
+ * @remote_node: pointer to device_node of the remote endpoint
+ * @remote_port: identifier of the port the remote endpoint belongs to
+ */
+struct v4l2_of_link {
+ struct device_node *local_node;
+ unsigned int local_port;
+ struct device_node *remote_node;
+ unsigned int remote_port;
+};
+
#ifdef CONFIG_OF
int v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *endpoint);
+int v4l2_of_parse_link(const struct device_node *node,
+ struct v4l2_of_link *link);
+void v4l2_of_put_link(struct v4l2_of_link *link);
#else /* CONFIG_OF */
static inline int v4l2_of_parse_endpoint(const struct device_node *node,
@@ -77,6 +94,16 @@ static inline int v4l2_of_parse_endpoint(const struct device_node *node,
return -ENOSYS;
}
+static inline int v4l2_of_parse_link(const struct device_node *node,
+ struct v4l2_of_link *link)
+{
+ return -ENOSYS;
+}
+
+static inline void v4l2_of_put_link(struct v4l2_of_link *link)
+{
+}
+
#endif /* CONFIG_OF */
#endif /* _V4L2_OF_H */
--
2.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
