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@gmail.com
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@kernel.org