[PATCH v2 3/3] common: Add fdt network helper functions

[Tony Dinh <mibodhi@gmail.com>]

Add fdt network helper functions fdt_support_net.c

Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Ramon Fried <rfried.dev@gmail.com>

Signed-off-by: Tony Dinh <mibodhi@gmail.com>
---

Changes in v2:
- Return FDT_ERR_NOTFOUND if fdt_get_phy_addr failed to find PHY addr
- Coding standards.

 common/fdt_support_net.c | 47 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 common/fdt_support_net.c

diff --git a/common/fdt_support_net.c b/common/fdt_support_net.c
new file mode 100644
index 0000000000..46fa12dd7c
--- /dev/null
+++ b/common/fdt_support_net.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 Tony Dinh <mibodhi@gmail.com>
+ */
+
+#include <asm/global_data.h>
+#include <fdt_support.h>
+#include <fdt_support_net.h>
+#include <linux/libfdt.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int fdt_get_phy_addr(const char *path)
+{
+	const void *fdt = gd->fdt_blob;
+	const u32 *reg;
+	const u32 *val;
+	int node, phandle, addr;
+
+	/* Find the node by its full path */
+	node = fdt_path_offset(fdt, path);
+	if (node >= 0) {
+		/* Look up phy-handle */
+		val = fdt_getprop(fdt, node, "phy-handle", NULL);
+		if (!val) {
+			/* Look up phy (deprecated property for phy handle) */
+			val = fdt_getprop(fdt, node, "phy", NULL);
+		}
+		if (val) {
+			phandle = fdt32_to_cpu(*val);
+			if (!phandle)
+				return -FDT_ERR_NOTFOUND;
+
+			/* Follow it to its node */
+			node = fdt_node_offset_by_phandle(fdt, phandle);
+			if (node) {
+				/* Look up reg */
+				reg = fdt_getprop(fdt, node, "reg", NULL);
+				if (reg) {
+					addr = fdt32_to_cpu(*reg);
+					return addr;
+				}
+			}
+		}
+	}
+	return -FDT_ERR_NOTFOUND;
+}
-- 
2.20.1