diff options
Diffstat (limited to 'arch/powerpc/kernel/prom_parse.c')
| -rw-r--r-- | arch/powerpc/kernel/prom_parse.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c index 12c51e4ad2b4..ea6fd552c7ea 100644 --- a/arch/powerpc/kernel/prom_parse.c +++ b/arch/powerpc/kernel/prom_parse.c @@ -5,6 +5,7 @@ #include <linux/pci_regs.h> #include <linux/module.h> #include <linux/ioport.h> +#include <linux/etherdevice.h> #include <asm/prom.h> #include <asm/pci-bridge.h> @@ -1003,3 +1004,42 @@ int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq return res; } EXPORT_SYMBOL_GPL(of_irq_map_one); + +/** + * 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); + |