[U-Boot] [PATCH 1/3] common: Fix-up MAC addr in dts by fetching env variable serially

[Prabhakar Kushwaha]

Current implementation of MAC address fix-up of device tree uses
tailing number behind "ethernet" found in "/aliases".  It is not
necessary for trailing number of “ethernet” to be sequential. There
can be hole in between or any node disabled.

So provide support device tree fix-up of “ethernent” node with MAC
addresses fetched sequentially from environment variables.

Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>
---
 README               | 10 ++++++++++
 common/fdt_support.c | 25 +++++++++++++++++++++----
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/README b/README
index 7a4f342..640b310 100644
--- a/README
+++ b/README
@@ -1603,6 +1603,16 @@ The following options need to be configured:
 
 		See doc/README.link-local for more information.
 
+ - MAC address from environment variables
+
+		FDT_SEQ_MACADDR_FROM_ENV
+
+		Fix-up device tree with MAC address fetched sequentially  from
+		environment variables. This will avoid dependency on device-tree
+		to get env variable sequence number. This config has assumption
+		of non-usable ethernet node of device-tree are either not present
+		or their status has been marked as "disabled".
+
  - CDP Options:
 		CONFIG_CDP_DEVICE_ID
 
diff --git a/common/fdt_support.c b/common/fdt_support.c
index f4f9543..43ca8db 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -469,12 +469,16 @@ int fdt_fixup_memory(void *blob, u64 start, u64 size)
 
 void fdt_fixup_ethernet(void *fdt)
 {
-	int i, j, prop;
+	int i = 0, j, prop;
 	char *tmp, *end;
 	char mac[16];
 	const char *path;
 	unsigned char mac_addr[ARP_HLEN];
 	int offset;
+#ifdef FDT_SEQ_MACADDR_FROM_ENV
+	int nodeoff;
+	const struct fdt_property *fdt_prop;
+#endif
 
 	if (fdt_path_offset(fdt, "/aliases") < 0)
 		return;
@@ -487,7 +491,7 @@ void fdt_fixup_ethernet(void *fdt)
 		offset = fdt_first_property_offset(fdt,
 			fdt_path_offset(fdt, "/aliases"));
 		/* Select property number 'prop' */
-		for (i = 0; i < prop; i++)
+		for (j = 0; j < prop; j++)
 			offset = fdt_next_property_offset(fdt, offset);
 
 		if (offset < 0)
@@ -496,11 +500,16 @@ void fdt_fixup_ethernet(void *fdt)
 		path = fdt_getprop_by_offset(fdt, offset, &name, NULL);
 		if (!strncmp(name, "ethernet", 8)) {
 			/* Treat plain "ethernet" same as "ethernet0". */
-			if (!strcmp(name, "ethernet"))
+			if (!strcmp(name, "ethernet")
+#ifdef FDT_SEQ_MACADDR_FROM_ENV
+			 || !strcmp(name, "ethernet0")
+#endif
+			)
 				i = 0;
+#ifndef FDT_SEQ_MACADDR_FROM_ENV
 			else
 				i = trailing_strtol(name);
-
+#endif
 			if (i != -1) {
 				if (i == 0)
 					strcpy(mac, "ethaddr");
@@ -509,6 +518,14 @@ void fdt_fixup_ethernet(void *fdt)
 			} else {
 				continue;
 			}
+#ifdef FDT_SEQ_MACADDR_FROM_ENV
+			nodeoff = fdt_path_offset(fdt, path);
+			fdt_prop = fdt_get_property(fdt, nodeoff, "status",
+						    NULL);
+			if (fdt_prop && !strcmp(fdt_prop->data, "disabled"))
+				continue;
+			i++;
+#endif
 			tmp = env_get(mac);
 			if (!tmp)
 				continue;
-- 
2.7.4