fdtdec: Add fdtdec_set_ethernet_mac_address()

This function can be used to set the local MAC address for the default Ethernet interface in its device tree node. The default interface is identified by the "ethernet" alias. One case where this is useful is for devices that store their MAC address in a custom location. Once extracted, board code can store the MAC address in U-Boot's control DTB so that it will automatically be used by the Ethernet uclass. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Tom Warren <twarren@nvidia.com>

fdtdec: Add fdtdec_set_ethernet_mac_address()
This function can be used to set the local MAC address for the default Ethernet interface in its device tree node. The default interface is identified by the "ethernet" alias. One case where this is useful is for devices that store their MAC address in a custom location. Once extracted, board code can store the MAC address in U-Boot's control DTB so that it will automatically be used by the Ethernet uclass. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Tom Warren <twarren@nvidia.com>
Thierry Reding · Tom Warren
1 parent 6d93d245c1
Showing 2 changed files with 53 additions and 0 deletions Side-by-side Diff
include/fdtdec.h
lib/fdtdec.c
@@ -997,6 +997,30 @@
 int fdtdec_setup_memory_banksize(void);
  
 /**
+ * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
+ *
+ * Looks up the default interface via the "ethernet" alias (in the /aliases
+ * node) and stores the given MAC in its "local-mac-address" property. This
+ * is useful on platforms that store the MAC address in a custom location.
+ * Board code can call this in the late init stage to make sure that the
+ * interface device tree node has the right MAC address configured for the
+ * Ethernet uclass to pick it up.
+ *
+ * Typically the FDT passed into this function will be U-Boot's control DTB.
+ * Given that a lot of code may be holding offsets to various nodes in that
+ * tree, this code will only set the "local-mac-address" property in-place,
+ * which means that it needs to exist and have space for the 6-byte address.
+ * This ensures that the operation is non-destructive and does not invalidate
+ * offsets that other drivers may be using.
+ *
+ * @param fdt FDT blob
+ * @param mac buffer containing the MAC address to set
+ * @param size size of MAC address
+ * @return 0 on success or a negative error code on failure
+ */
+int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size);
+
+/**
  * fdtdec_set_phandle() - sets the phandle of a given node
  *
  * @param blob		FDT blob
@@ -1261,6 +1261,35 @@
 }
 #endif
  
+int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size)
+{
+	const char *path;
+	int offset, err;
+
+	if (!is_valid_ethaddr(mac))
+		return -EINVAL;
+
+	path = fdt_get_alias(fdt, "ethernet");
+	if (!path)
+		return 0;
+
+	debug("ethernet alias found: %s\n", path);
+
+	offset = fdt_path_offset(fdt, path);
+	if (offset < 0) {
+		debug("ethernet alias points to absent node %s\n", path);
+		return -ENOENT;
+	}
+
+	err = fdt_setprop_inplace(fdt, offset, "local-mac-address", mac, size);
+	if (err < 0)
+		return err;
+
+	debug("MAC address: %pM\n", mac);
+
+	return 0;
+}
+
 static int fdtdec_init_reserved_memory(void *blob)
 {
 	int na, ns, node, err;
...	...	@@ -997,6 +997,30 @@
997	997	int fdtdec_setup_memory_banksize(void);
998	998
999	999	/**
	1000	+ * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
	1001	+ *
	1002	+ * Looks up the default interface via the "ethernet" alias (in the /aliases
	1003	+ * node) and stores the given MAC in its "local-mac-address" property. This
	1004	+ * is useful on platforms that store the MAC address in a custom location.
	1005	+ * Board code can call this in the late init stage to make sure that the
	1006	+ * interface device tree node has the right MAC address configured for the
	1007	+ * Ethernet uclass to pick it up.
	1008	+ *
	1009	+ * Typically the FDT passed into this function will be U-Boot's control DTB.
	1010	+ * Given that a lot of code may be holding offsets to various nodes in that
	1011	+ * tree, this code will only set the "local-mac-address" property in-place,
	1012	+ * which means that it needs to exist and have space for the 6-byte address.
	1013	+ * This ensures that the operation is non-destructive and does not invalidate
	1014	+ * offsets that other drivers may be using.
	1015	+ *
	1016	+ * @param fdt FDT blob
	1017	+ * @param mac buffer containing the MAC address to set
	1018	+ * @param size size of MAC address
	1019	+ * @return 0 on success or a negative error code on failure
	1020	+ */
	1021	+int fdtdec_set_ethernet_mac_address(void fdt, const u8 mac, size_t size);
	1022	+
	1023	+/**
1000	1024	* fdtdec_set_phandle() - sets the phandle of a given node
1001	1025	*
1002	1026	* @param blob FDT blob
...	...	@@ -1261,6 +1261,35 @@
1261	1261	}
1262	1262	#endif
1263	1263
	1264	+int fdtdec_set_ethernet_mac_address(void fdt, const u8 mac, size_t size)
	1265	+{
	1266	+ const char *path;
	1267	+ int offset, err;
	1268	+
	1269	+ if (!is_valid_ethaddr(mac))
	1270	+ return -EINVAL;
	1271	+
	1272	+ path = fdt_get_alias(fdt, "ethernet");
	1273	+ if (!path)
	1274	+ return 0;
	1275	+
	1276	+ debug("ethernet alias found: %s\n", path);
	1277	+
	1278	+ offset = fdt_path_offset(fdt, path);
	1279	+ if (offset < 0) {
	1280	+ debug("ethernet alias points to absent node %s\n", path);
	1281	+ return -ENOENT;
	1282	+ }
	1283	+
	1284	+ err = fdt_setprop_inplace(fdt, offset, "local-mac-address", mac, size);
	1285	+ if (err < 0)
	1286	+ return err;
	1287	+
	1288	+ debug("MAC address: %pM\n", mac);
	1289	+
	1290	+ return 0;
	1291	+}
	1292	+
1264	1293	static int fdtdec_init_reserved_memory(void *blob)
1265	1294	{
1266	1295	int na, ns, node, err;