On Thu, Jun 18, 2020 at 01:26:57AM +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 of the graph.
>
> This patch adds of_graph_presents() that returns true if given device-tree
> node contains OF graph port.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/of/property.c | 52 +++++++++++++++++++++++++++++++++-------
> include/linux/of_graph.h | 6 +++++
> 2 files changed, 49 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 1f2086f4e7ce..b84ed6a7cf50 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -29,6 +29,48 @@
>
> #include "of_private.h"
>
> +/**
> + * of_graph_get_first_local_port() - get first 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.
> + */
> +static struct device_node *
> +of_graph_get_first_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;
> +}
> +
> +/**
> + * of_graph_presents() - check graph's presence
> + * @node: pointer to a device_node checked for the graph's presence
> + *
> + * Return: True if @node has a port or ports sub-node, false otherwise.
> + */
> +bool of_graph_presents(const struct device_node *node)
of_graph_is_present
Otherwise,
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
