diff options
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-of.c | 61 | ||||
| -rw-r--r-- | include/media/v4l2-of.h | 27 |
2 files changed, 88 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c index 58e401f4893a..83143d39dea7 100644 --- a/drivers/media/v4l2-core/v4l2-of.c +++ b/drivers/media/v4l2-core/v4l2-of.c @@ -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); diff --git a/include/media/v4l2-of.h b/include/media/v4l2-of.h index 2de42c584eb2..f831c9c225b6 100644 --- a/include/media/v4l2-of.h +++ b/include/media/v4l2-of.h @@ -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 */ |