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authorDavid Daney <ddaney@caviumnetworks.com>2010-10-27 02:07:13 +0400
committerGrant Likely <grant.likely@secretlab.ca>2010-11-01 08:08:14 +0300
commit4b6ba8aacbb3185703b797286547d0f8f3859b02 (patch)
treef4e04c3b19d6bf7c7429c0cf678c534838e2990d /drivers/of/of_net.c
parent3985c7ce85039adacdf882904ca096f091d39346 (diff)
downloadlinux-4b6ba8aacbb3185703b797286547d0f8f3859b02.tar.xz
of/net: Move of_get_mac_address() to a common source file.
There are two identical implementations of of_get_mac_address(), one each in arch/powerpc/kernel/prom_parse.c and arch/microblaze/kernel/prom_parse.c. Move this function to a new common file of_net.{c,h} and adjust all the callers to include the new header. Signed-off-by: David Daney <ddaney@caviumnetworks.com> [grant.likely@secretlab.ca: protect header with #ifdef] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/of/of_net.c')
-rw-r--r--drivers/of/of_net.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
new file mode 100644
index 000000000000..86f334a2769c
--- /dev/null
+++ b/drivers/of/of_net.c
@@ -0,0 +1,48 @@
+/*
+ * OF helpers for network devices.
+ *
+ * This file is released under the GPLv2
+ *
+ * Initially copied out of arch/powerpc/kernel/prom_parse.c
+ */
+#include <linux/etherdevice.h>
+#include <linux/kernel.h>
+#include <linux/of_net.h>
+
+/**
+ * Search the device tree for the best MAC address to use. 'mac-address' is
+ * checked first, because that is supposed to contain to "most recent" MAC
+ * address. If that isn't set, then 'local-mac-address' is checked next,
+ * because that is the default address. If that isn't set, then the obsolete
+ * 'address' is checked, just in case we're using an old device tree.
+ *
+ * Note that the 'address' property is supposed to contain a virtual address of
+ * the register set, but some DTS files have redefined that property to be the
+ * MAC address.
+ *
+ * All-zero MAC addresses are rejected, because those could be properties that
+ * exist in the device tree, but were not set by U-Boot. For example, the
+ * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
+ * addresses. Some older U-Boots only initialized 'local-mac-address'. In
+ * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
+ * but is all zeros.
+*/
+const void *of_get_mac_address(struct device_node *np)
+{
+ struct property *pp;
+
+ pp = of_find_property(np, "mac-address", NULL);
+ if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
+ return pp->value;
+
+ pp = of_find_property(np, "local-mac-address", NULL);
+ if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
+ return pp->value;
+
+ pp = of_find_property(np, "address", NULL);
+ if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
+ return pp->value;
+
+ return NULL;
+}
+EXPORT_SYMBOL(of_get_mac_address);