[PATCH 1/2] of: Add helper to lookup non port child node
Jagan Teki
jagan at amarulasolutions.com
Tue Dec 7 05:47:46 UTC 2021
Add of_get_non_port_child() helper that can be used to lookup
non port child nodes.
Some OF graphs don't require 'ports' to represent the next output
instead, it simply adds a child node on a given parent node. This
helper lookup that child node, however that child node is not a
'port' on given parent as 'port' based nodes are looked up via
of_graph_get_remote_node().
Example OF graph representation of DSI host, which doesn't
have 'ports'.
dsi {
#address-cells = <1>;
#size-cells = <0>;
port {
dsi_in_tcon0: endpoint {
remote-endpoint = <tcon0_out_dsi>;
};
panel at 0 {
reg = <0>;
};
};
Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
---
drivers/of/base.c | 29 +++++++++++++++++++++++++++++
include/linux/of.h | 6 ++++++
2 files changed, 35 insertions(+)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 61de453b885c..31bbf885b0f8 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -854,6 +854,35 @@ struct device_node *of_get_compatible_child(const struct device_node *parent,
}
EXPORT_SYMBOL(of_get_compatible_child);
+/**
+ * of_get_non_port_child - Find the non port child node for a given parent
+ * @node: parent node
+ *
+ * This function looks for child node which is not port child for given parent.
+ *
+ * Return: A node pointer if found, with refcount incremented, use
+ * of_node_put() on it when done.
+ * Returns NULL if node is not found.
+ */
+struct device_node *of_get_non_port_child(const struct device_node *parent)
+{
+ struct device_node *child;
+
+ for_each_child_of_node(parent, child) {
+ if (of_node_name_eq(child, "port"))
+ continue;
+
+ if (!of_device_is_available(child)) {
+ of_node_put(child);
+ continue;
+ }
+ break;
+ }
+
+ return child;
+}
+EXPORT_SYMBOL(of_get_non_port_child);
+
/**
* of_get_child_by_name - Find the child node by name for a given parent
* @node: parent node
diff --git a/include/linux/of.h b/include/linux/of.h
index ff143a027abc..3e699becef82 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -290,6 +290,7 @@ extern struct device_node *of_get_next_child(const struct device_node *node,
extern struct device_node *of_get_next_available_child(
const struct device_node *node, struct device_node *prev);
+extern struct device_node *of_get_non_port_child(const struct device_node *parent);
extern struct device_node *of_get_compatible_child(const struct device_node *parent,
const char *compatible);
extern struct device_node *of_get_child_by_name(const struct device_node *node,
@@ -678,6 +679,11 @@ static inline bool of_have_populated_dt(void)
return false;
}
+static inline struct device_node *of_get_non_port_child(const struct device_node *parent)
+{
+ return NULL;
+}
+
static inline struct device_node *of_get_compatible_child(const struct device_node *parent,
const char *compatible)
{
--
2.25.1
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