From: John Crispin <blogic@openwrt.org> Date: Sun, 27 Jul 2014 09:40:01 +0100 Subject: NET: add mtd-mac-address support to of_get_mac_address() Many embedded devices have information such as mac addresses stored inside mtd devices. This patch allows us to add a property inside a node describing a network interface. The new property points at a mtd partition with an offset where the mac address can be found. Signed-off-by: John Crispin <blogic@openwrt.org> Signed-off-by: Felix Fietkau <nbd@nbd.name> --- drivers/of/of_net.c | 37 +++++++++++++++++++++++++++++++++++++ include/linux/of_net.h | 1 + 2 files changed, 38 insertions(+) --- a/drivers/of/of_net.c +++ b/drivers/of/of_net.c @@ -10,6 +10,7 @@ #include <linux/of_net.h> #include <linux/phy.h> #include <linux/export.h> +#include <linux/mtd/mtd.h> /** * of_get_phy_mode - Get phy mode for given device_node @@ -38,7 +39,7 @@ int of_get_phy_mode(struct device_node * } EXPORT_SYMBOL_GPL(of_get_phy_mode); -static const void *of_get_mac_addr(struct device_node *np, const char *name) +static void *of_get_mac_addr(struct device_node *np, const char *name) { struct property *pp = of_find_property(np, name, NULL); @@ -47,6 +48,73 @@ static const void *of_get_mac_addr(struc return NULL; } +static const void *of_get_mac_address_mtd(struct device_node *np) +{ +#ifdef CONFIG_MTD + struct device_node *mtd_np = NULL; + struct property *prop; + size_t retlen; + int size, ret; + struct mtd_info *mtd; + const char *part; + const __be32 *list; + phandle phandle; + u32 mac_inc = 0; + u8 mac[ETH_ALEN]; + void *addr; + + list = of_get_property(np, "mtd-mac-address", &size); + if (!list || (size != (2 * sizeof(*list)))) + return NULL; + + phandle = be32_to_cpup(list++); + if (phandle) + mtd_np = of_find_node_by_phandle(phandle); + + if (!mtd_np) + return NULL; + + part = of_get_property(mtd_np, "label", NULL); + if (!part) + part = mtd_np->name; + + mtd = get_mtd_device_nm(part); + if (IS_ERR(mtd)) + return NULL; + + ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac); + put_mtd_device(mtd); + + if (!of_property_read_u32(np, "mtd-mac-address-increment", &mac_inc)) + mac[5] += mac_inc; + + if (!is_valid_ether_addr(mac)) + return NULL; + + addr = of_get_mac_addr(np, "mac-address"); + if (addr) { + memcpy(addr, mac, ETH_ALEN); + return addr; + } + + prop = kzalloc(sizeof(*prop), GFP_KERNEL); + if (!prop) + return NULL; + + prop->name = "mac-address"; + prop->length = ETH_ALEN; + prop->value = kmemdup(mac, ETH_ALEN, GFP_KERNEL); + if (!prop->value || of_add_property(np, prop)) + goto free; + + return prop->value; +free: + kfree(prop->value); + kfree(prop); +#endif + return NULL; +} + /** * 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 @@ -64,11 +132,18 @@ static const void *of_get_mac_addr(struc * 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. + * + * If a mtd-mac-address property exists, try to fetch the MAC address from the + * specified mtd device, and store it as a 'mac-address' property */ const void *of_get_mac_address(struct device_node *np) { const void *addr; + addr = of_get_mac_address_mtd(np); + if (addr) + return addr; + addr = of_get_mac_addr(np, "mac-address"); if (addr) return addr;