From 639dba857aa554f2a78572adc4cf3c32de9ec2e2 Mon Sep 17 00:00:00 2001 From: Ansuel Smith Date: Tue, 30 Mar 2021 18:21:14 +0200 Subject: [PATCH 2/2] of_net: add mac-address-increment support Lots of embedded devices use the mac-address of other interface extracted from nvmem cells and increments it by one or two. Add two bindings to integrate this and directly use the right mac-address for the interface. Some example are some routers that use the gmac mac-address stored in the art partition and increments it by one for the wifi. mac-address-increment-byte bindings is used to tell what byte of the mac-address has to be increased (if not defined the last byte is increased) and mac-address-increment tells how much the byte decided early has to be increased. Signed-off-by: Ansuel Smith --- drivers/of/of_net.c | 59 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 45 insertions(+), 14 deletions(-) diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c index f072e2509cc9..0dbd1f7ef396 100644 --- a/drivers/of/of_net.c +++ b/drivers/of/of_net.c @@ -55,31 +55,36 @@ static void *of_get_mac_addr(struct device_node *np, const char *name) return NULL; } -static const void *of_get_mac_addr_nvmem(struct device_node *np) +static void *of_get_mac_addr_nvmem(struct device_node *np, int *err) { int ret; - const void *mac; + void *mac; u8 nvmem_mac[ETH_ALEN]; struct platform_device *pdev = of_find_device_by_node(np); - if (!pdev) - return ERR_PTR(-ENODEV); + if (!pdev) { + *err = -ENODEV; + return NULL; + } ret = nvmem_get_mac_address(&pdev->dev, &nvmem_mac); if (ret) { put_device(&pdev->dev); - return ERR_PTR(ret); + *err = ret; + return NULL; } mac = devm_kmemdup(&pdev->dev, nvmem_mac, ETH_ALEN, GFP_KERNEL); put_device(&pdev->dev); - if (!mac) - return ERR_PTR(-ENOMEM); + if (!mac) { + *err = -ENOMEM; + return NULL; + } return mac; } -static const void *of_get_mac_address_mtd(struct device_node *np) +static void *of_get_mac_address_mtd(struct device_node *np) { #ifdef CONFIG_MTD struct device_node *mtd_np = NULL; @@ -167,28 +172,54 @@ static const void *of_get_mac_address_mtd(struct device_node *np) * 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 * + * DT can tell the system to increment the mac-address after is extracted by + * using: + * - mac-address-increment-byte to decide what byte to increase + * (if not defined is increased the last byte) + * - mac-address-increment to decide how much to increase. The value will + * not overflow to other bytes if the increment is over 255. + * (example 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00) + * * 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; + u32 inc_idx, mac_inc; + int ret = 0; + u8 *addr; + + /* Check first if the increment byte is present and valid. + * If not set assume to increment the last byte if found. + */ + if (of_property_read_u32(np, "mac-address-increment-byte", &inc_idx)) + inc_idx = 5; + if (inc_idx < 3 || inc_idx > 5) + return ERR_PTR(-EINVAL); addr = of_get_mac_addr(np, "mac-address"); if (addr) - return addr; + goto found; addr = of_get_mac_addr(np, "local-mac-address"); if (addr) - return addr; + goto found; addr = of_get_mac_addr(np, "address"); if (addr) - return addr; + goto found; addr = of_get_mac_address_mtd(np); if (addr) - return addr; + goto found; + + addr = of_get_mac_addr_nvmem(np, &ret); + if (ret) + return ERR_PTR(ret); + +found: + if (!of_property_read_u32(np, "mac-address-increment", &mac_inc)) + addr[inc_idx] += mac_inc; - return of_get_mac_addr_nvmem(np); + return addr; } EXPORT_SYMBOL(of_get_mac_address); -- 2.30.2