Hi Dmitry,
Thank you for the patch.
On Sun, Jun 14, 2020 at 08:22:29PM +0300, Dmitry Osipenko wrote:
> In some case, like a DRM display code for example, it's useful to silently
> check whether port node exists at all in a device-tree before proceeding
> with parsing the graph.
>
> This patch adds of_graph_get_local_port() which returns pointer to a local
> port node, or NULL if graph isn't specified in a device-tree for a given
> device node.
>
> Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/of/property.c | 32 +++++++++++++++++++++++---------
> include/linux/of_graph.h | 7 +++++++
> 2 files changed, 30 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 1f2086f4e7ce..05c5f619b8bb 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -608,15 +608,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
> * parent port node.
> */
> if (!prev) {
> - struct device_node *node;
> -
> - node = of_get_child_by_name(parent, "ports");
> - if (node)
> - parent = node;
> -
> - port = of_get_child_by_name(parent, "port");
> - of_node_put(node);
> -
> + port = of_graph_get_local_port(parent);
> if (!port) {
> pr_err("graph: no port node found in %pOF\n", parent);
> return NULL;
> @@ -765,6 +757,28 @@ struct device_node *of_graph_get_remote_port(const struct device_node *node)
> }
> EXPORT_SYMBOL(of_graph_get_remote_port);
>
> +/**
> + * of_graph_get_local_port() - get local port node
> + * @node: pointer to a local endpoint device_node
> + *
> + * Return: First local port node associated with local endpoint node linked
> + * to @node. Use of_node_put() on it when done.
> + */
> +struct device_node *of_graph_get_local_port(const struct device_node *node)
> +{
> + struct device_node *ports, *port;
> +
> + ports = of_get_child_by_name(node, "ports");
> + if (ports)
> + node = ports;
> +
> + port = of_get_child_by_name(node, "port");
> + of_node_put(ports);
> +
> + return port;
The implementation doesn't seem to match the documentation. If node is a
pointer to an endpoint, it should not have any ports child.
> +}
> +EXPORT_SYMBOL(of_graph_get_local_port);
> +
> int of_graph_get_endpoint_count(const struct device_node *np)
> {
> struct device_node *endpoint;
> diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h
> index 01038a6aade0..1fdeb72c7765 100644
> --- a/include/linux/of_graph.h
> +++ b/include/linux/of_graph.h
> @@ -54,6 +54,7 @@ struct device_node *of_graph_get_remote_port_parent(
> struct device_node *of_graph_get_remote_port(const struct device_node *node);
> struct device_node *of_graph_get_remote_node(const struct device_node *node,
> u32 port, u32 endpoint);
> +struct device_node *of_graph_get_local_port(const struct device_node *node);
> #else
>
> static inline int of_graph_parse_endpoint(const struct device_node *node,
> @@ -116,6 +117,12 @@ static inline struct device_node *of_graph_get_remote_node(
> return NULL;
> }
>
> +static inline struct device_node *of_graph_get_local_port(
> + const struct device_node *node)
> +{
> + return NULL;
> +}
> +
> #endif /* CONFIG_OF */
>
> #endif /* __LINUX_OF_GRAPH_H */
> --
> 2.26.0
>
--
Regards,
Laurent Pinchart
