From: John Crispin 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 Signed-off-by: Felix Fietkau --- 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 @@ -11,6 +11,7 @@ #include #include #include +#include /** * of_get_phy_mode - Get phy mode for given device_node @@ -39,7 +40,7 @@ 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); @@ -72,6 +73,138 @@ static const void *of_get_mac_addr_nvmem return mac; } +typedef int(*mtd_mac_address_read)(struct mtd_info *mtd, loff_t from, u_char *buf); + +static int read_mtd_mac_address(struct mtd_info *mtd, loff_t from, u_char *mac) +{ + size_t retlen; + + return mtd_read(mtd, from, 6, &retlen, mac); +} + +static int read_mtd_mac_address_ascii(struct mtd_info *mtd, loff_t from, u_char *mac) +{ + size_t retlen; + char buf[17]; + + if (mtd_read(mtd, from, 12, &retlen, buf)) { + return -1; + } + if (sscanf(buf, "%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx", + &mac[0], &mac[1], &mac[2], &mac[3], + &mac[4], &mac[5]) == 6) { + if (mac[0] == '\0' && mac[1] == '\0') { /* First 2 bytes are zero, probably a bug. Trying to re-read */ + buf[4] = '\0'; /* Make it null-terminated */ + if (sscanf(buf, "%4hx", mac) == 1) + *(uint16_t*)mac = htons(*(uint16_t*)mac); + } + return 0; + } + if (mtd_read(mtd, from+12, 5, &retlen, buf+12)) { + return -1; + } + if (sscanf(buf, "%2hhx:%2hhx:%2hhx:%2hhx:%2hhx:%2hhx", + &mac[0], &mac[1], &mac[2], &mac[3], + &mac[4], &mac[5]) == 6) { + return 0; + } + return -1; +} + +static struct mtd_mac_address_property { + char *name; + mtd_mac_address_read read; +} mtd_mac_address_properties[] = { + { + .name = "mtd-mac-address", + .read = read_mtd_mac_address, + }, { + .name = "mtd-mac-address-ascii", + .read = read_mtd_mac_address_ascii, + }, +}; + +static const void *of_get_mac_address_mtd(struct device_node *np) +{ +#ifdef CONFIG_MTD + struct device_node *mtd_np = NULL; + struct property *prop; + int size, ret = -1; + struct mtd_info *mtd; + const char *part; + const __be32 *list; + phandle phandle; + u32 mac_inc = 0; + u8 mac[ETH_ALEN]; + void *addr; + u32 inc_idx; + int i; + + for (i = 0; i < ARRAY_SIZE(mtd_mac_address_properties); i++) { + list = of_get_property(np, mtd_mac_address_properties[i].name, &size); + if (!list || (size != (2 * sizeof(*list)))) + continue; + + phandle = be32_to_cpup(list++); + if (phandle) + mtd_np = of_find_node_by_phandle(phandle); + + if (!mtd_np) + continue; + + part = of_get_property(mtd_np, "label", NULL); + if (!part) + part = mtd_np->name; + + mtd = get_mtd_device_nm(part); + if (IS_ERR(mtd)) + continue; + + ret = mtd_mac_address_properties[i].read(mtd, be32_to_cpup(list), mac); + put_mtd_device(mtd); + if (!ret) { + break; + } + } + if (ret) { + return NULL; + } + + if (of_property_read_u32(np, "mtd-mac-address-increment-byte", &inc_idx)) + inc_idx = 5; + if (inc_idx > 5) + return NULL; + + if (!of_property_read_u32(np, "mtd-mac-address-increment", &mac_inc)) + mac[inc_idx] += 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 @@ -92,12 +225,20 @@ static const void *of_get_mac_addr_nvmem * 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 + * * Return: Will be a valid pointer on success and ERR_PTR in case of error. */ 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;