[PATCH 5/8] dm: core: implement phandle ofnode_options helper

[Christian Marangi <ansuelsmth@gmail.com>]

Implement ofnode_options phandle helper to get an ofnode from a phandle
option in /options/u-boot.

This helper can be useful since new DT yaml usually require to link a
phandle of a node instead of referencing it by name or other indirect
way.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/core/ofnode.c | 15 +++++++++++++++
 include/dm/ofnode.h   | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 774b428c43f..3a96bf4f0c5 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -1871,6 +1871,21 @@ const char *ofnode_options_read_str(const char *prop_name)
 	return ofnode_read_string(uboot, prop_name);
 }
 
+int ofnode_options_get_by_phandle(const char *prop_name, ofnode *nodep)
+{
+	ofnode uboot;
+
+	uboot = ofnode_path("/options/u-boot");
+	if (!ofnode_valid(uboot))
+		return -EINVAL;
+
+	*nodep = ofnode_parse_phandle(uboot, prop_name, 0);
+	if (!ofnode_valid(*nodep))
+		return -EINVAL;
+
+	return 0;
+}
+
 int ofnode_read_bootscript_address(u64 *bootscr_address, u64 *bootscr_offset)
 {
 	int ret;
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index eea6b13217c..890f0e6cf40 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -1720,6 +1720,21 @@ int ofnode_options_read_int(const char *prop_name, int default_val);
  */
 const char *ofnode_options_read_str(const char *prop_name);
 
+/**
+ * ofnode_options_get_by_phandle() - Get a ofnode from phandle from the U-Boot options
+ *
+ * This reads a property from the /options/u-boot/ node of the devicetree.
+ *
+ * This only works with the control FDT.
+ *
+ * See dtschema/schemas/options/u-boot.yaml in dt-schema project for bindings
+ *
+ * @prop_name: property name to look up
+ * @nodep: pointer to ofnode where node is stored
+ * Return: 0, if found, or negative error if not
+ */
+int ofnode_options_get_by_phandle(const char *prop_name, ofnode *nodep);
+
 /**
  * ofnode_read_bootscript_address() - Read bootscr-address or bootscr-ram-offset
  *
-- 
2.45.2