From 6f8e5369ae054ec6c9265581d5a7e39738a5cd84 Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Tue, 30 Mar 2021 13:16:38 +0200 Subject: [PATCH 1/2] 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 Signed-off-by: Ansuel Smith --- drivers/of/of_net.c | 75 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 74 insertions(+), 1 deletion(-) --- 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 @@ -45,7 +46,7 @@ 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); @@ -78,6 +79,70 @@ static const void *of_get_mac_addr_nvmem return mac; } +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; + 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 (!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 @@ -98,6 +163,10 @@ 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) @@ -116,6 +185,10 @@ const void *of_get_mac_address(struct de if (addr) return addr; + addr = of_get_mac_address_mtd(np); + if (addr) + return addr; + return of_get_mac_addr_nvmem(np); } EXPORT_SYMBOL(of_get_mac_address);