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[RFC,1/2] OMAP2+: add cpu id register to MAC address helper

Message ID 20110324212729.14936.98130.stgit@otae.warmcat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Andy Green March 24, 2011, 9:27 p.m. UTC
None
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Patch

diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c
index 2537090..e46b430 100644
--- a/arch/arm/mach-omap2/id.c
+++ b/arch/arm/mach-omap2/id.c
@@ -557,3 +557,42 @@  void __init omap2_set_globals_tap(struct omap_globals *omap2_globals)
 	else
 		tap_prod_id = 0x0208;
 }
+
+/*
+ * this uses the unique per-cpu info from the cpu fuses set at factory to
+ * generate a 6-byte MAC address.  Two bits in the generated code are used
+ * to elaborate the generated address into four, so it can be used on multiple
+ * network interfaces.
+ */
+
+void omap2_die_id_to_ethernet_mac(u8 *mac, int subtype)
+{
+	struct omap_die_id odi;
+	u32 tap = read_tap_reg(OMAP_TAP_IDCODE);
+
+	omap_get_die_id(&odi);
+
+	mac[0] = odi.id_2;
+	mac[1] = odi.id_2 >> 8;
+	mac[2] = odi.id_1;
+	mac[3] = odi.id_1 >> 8;
+	mac[4] = odi.id_1 >> 16;
+	mac[5] = odi.id_1 >> 24;
+
+	/* XOR other chip-specific data with ID */
+
+	tap ^= odi.id_3;
+
+	mac[0] ^= tap;
+	mac[1] ^= tap >> 8;
+	mac[2] ^= tap >> 16;
+	mac[3] ^= tap >> 24;
+
+	/* allow four MACs from this same basic data */
+
+	mac[1] = (mac[1] & ~0xc0) | ((subtype & 3) << 6);
+
+	/* mark it as not multicast and outside official 80211 MAC namespace */
+
+	mac[0] = (mac[0] & ~1) | 2;
+}
diff --git a/arch/arm/mach-omap2/include/mach/id.h b/arch/arm/mach-omap2/include/mach/id.h
index 02ed3aa..373313a 100644
--- a/arch/arm/mach-omap2/include/mach/id.h
+++ b/arch/arm/mach-omap2/include/mach/id.h
@@ -18,5 +18,6 @@  struct omap_die_id {
 };
 
 void omap_get_die_id(struct omap_die_id *odi);
+void omap2_die_id_to_ethernet_mac(u8 *mac, int subtype);
 
 #endif