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 @@ -12,6 +12,7 @@ #include #include #include +#include /** * of_get_phy_mode - Get phy mode for given device_node @@ -95,6 +96,52 @@ static int of_get_mac_addr_nvmem(struct return 0; } +static int of_get_mac_address_mtd(struct device_node *np, u8 *addr) +{ +#ifdef CONFIG_MTD + struct platform_device *pdev = of_find_device_by_node(np); + struct device_node *mtd_np = NULL; + size_t retlen; + int size, ret; + struct mtd_info *mtd; + const char *part; + const __be32 *list; + phandle phandle; + u8 mac[ETH_ALEN]; + + list = of_get_property(np, "mtd-mac-address", &size); + if (!list || (size != (2 * sizeof(*list)))) + return -ENODEV; + + phandle = be32_to_cpup(list++); + if (phandle) + mtd_np = of_find_node_by_phandle(phandle); + + if (!mtd_np) + return -ENODEV; + + 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 -ENODEV; + + ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac); + put_mtd_device(mtd); + + if (!is_valid_ether_addr(mac)) + return -EINVAL; + + memcpy(addr, mac, ETH_ALEN); + + return 0; +#endif + return -EINVAL; +} + + /** * 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 @@ -115,6 +162,10 @@ static int of_get_mac_addr_nvmem(struct * 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. + * * Return: 0 on success and errno in case of error. */ int of_get_mac_address(struct device_node *np, u8 *addr) @@ -136,6 +187,10 @@ int of_get_mac_address(struct device_nod if (!ret) return 0; + ret = of_get_mac_address_mtd(np, addr); + if (!ret) + return 0; + return of_get_mac_addr_nvmem(np, addr); } EXPORT_SYMBOL(of_get_mac_address);