Commit c9bca8b3 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab

[media] v4l: of: Add v4l2_of_parse_link() function

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: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Acked-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent 2dca0551
......@@ -165,3 +165,64 @@ 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's 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);
......@@ -69,9 +69,26 @@ 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,
......@@ -80,6 +97,16 @@ 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 */
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