[PATCH 2/8] w1: introduce helper to generate mac address from 1-wire id

[Jean-Christophe PLAGNIOL-VILLARD]

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 include/w1_mac_address.h |   64 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 include/w1_mac_address.h

diff --git a/include/w1_mac_address.h b/include/w1_mac_address.h
new file mode 100644
index 0000000..ed93e0e
--- /dev/null
+++ b/include/w1_mac_address.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnio at jcrosoft.com>
+ *
+ * Under GPLv2 only
+ */
+
+#ifndef __W1_MAC_ADDRESS_H__
+#define __W1_MAC_ADDRESS_H__
+
+static inline int w1_mac_address_register(int eth_num, bool local,
+					 char * oui, char *w1_dev)
+{
+	char buf[6];
+	const char *val;
+	u64 id;
+	int nb_oui = 0;
+	int i, shift;
+	char *tmp = NULL;
+	int ret = 0;
+
+	if (!local && !oui)
+		return -EINVAL;
+
+	if (oui) {
+		nb_oui = strlen(oui);
+		if (!local && nb_oui != 3)
+			return -EINVAL;
+
+		nb_oui = min(nb_oui, 3);
+
+		for (i = 0; i < nb_oui; i++)
+			buf[i] = oui[i];
+	}
+
+	tmp = asprintf("%s.id", w1_dev);
+	if (!tmp)
+		return -ENOMEM;
+
+	val = getenv("w1-1-0.id");
+	if (!val) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	id = simple_strtoull(val, NULL, 16);
+	if (!id) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	for (i = nb_oui, shift = 40; i < 6; i++, shift -= 8)
+		buf[i] = (id >> shift) & 0xff;
+
+	if (local)
+		buf[0] |= 0x2;
+
+	eth_register_ethaddr(eth_num, buf);
+
+err:
+	free(tmp);
+	return ret;
+}
+
+#endif /* __W1_MAC_ADDRESS_H__ */
-- 
1.7.10.4