diff options
| author | Andy Green <andy@warmcat.com> | 2011-03-24 21:27:29 +0000 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-03-27 22:06:32 -0400 |
| commit | 1da46fc5bbdbaba801f66e8419d3195924e1a5f3 (patch) | |
| tree | 4d3ccfc9938ed12c63863038c6e60f98cc249c82 | |
| parent | 7aa1471f64882e97ce45189967e66a0757903243 (diff) | |
OMAP2+: add cpu id register to MAC address helper
Introduce a generic helper function that can set a MAC address using
data from the OMAP unique CPU ID register.
For comparison purposes this produces a MAC address of
2e:40:70:f0:12:06
for the ethernet device on my Panda.
Signed-off-by: Andy Green <andy.green@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
| -rw-r--r-- | arch/arm/mach-omap2/id.c | 39 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/include/mach/id.h | 1 |
2 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/id.c b/arch/arm/mach-omap2/id.c index 2537090aa33..e46b430c701 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 02ed3aa56f1..373313a51b8 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 |