From 4ec0a44ba8d797876ff416fc0317a0169483d240 Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Wed, 1 Jul 2020 10:42:31 +0300 Subject: of_graph: add of_graph_is_present() In some cases it's very useful to silently check whether port node exists at all in a device-tree before proceeding with parsing the graph. The DRM bridges code is one example of such case where absence of a graph in a device-tree is a legit condition. This patch adds of_graph_is_present() which returns true if given device-tree node contains OF graph port. Reviewed-by: Rob Herring Signed-off-by: Dmitry Osipenko Reviewed-by: Laurent Pinchart Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200701074232.13632-2-digetx@gmail.com --- include/linux/of_graph.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include') diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h index 01038a6aade0..4d7756087b6b 100644 --- a/include/linux/of_graph.h +++ b/include/linux/of_graph.h @@ -38,6 +38,7 @@ struct of_endpoint { child = of_graph_get_next_endpoint(parent, child)) #ifdef CONFIG_OF +bool of_graph_is_present(const struct device_node *node); int of_graph_parse_endpoint(const struct device_node *node, struct of_endpoint *endpoint); int of_graph_get_endpoint_count(const struct device_node *np); @@ -56,6 +57,11 @@ struct device_node *of_graph_get_remote_node(const struct device_node *node, u32 port, u32 endpoint); #else +static inline bool of_graph_is_present(const struct device_node *node) +{ + return false; +} + static inline int of_graph_parse_endpoint(const struct device_node *node, struct of_endpoint *endpoint) { -- cgit v1.2.3