target/linux/generic/pending-5.10/681-NET-add-mtd-mac-address-support-to-of_get_mac_addres.patch

   1 From 6f8e5369ae054ec6c9265581d5a7e39738a5cd84 Mon Sep 17 00:00:00 2001
   2 From: Ansuel Smith <ansuelsmth@gmail.com>
   3 Date: Tue, 30 Mar 2021 13:16:38 +0200
   4 Subject: [PATCH 1/2] NET: add mtd-mac-address support to of_get_mac_address()
   5
   6 Many embedded devices have information such as mac addresses stored inside mtd
   7 devices. This patch allows us to add a property inside a node describing a
   8 network interface. The new property points at a mtd partition with an offset
   9 where the mac address can be found.
  10
  11 Signed-off-by: John Crispin <blogic@openwrt.org>
  12 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  13 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
  14 ---
  15  drivers/of/of_net.c | 75 ++++++++++++++++++++++++++++++++++++++++++++-
  16  1 file changed, 74 insertions(+), 1 deletion(-)
  17
  18 --- a/drivers/of/of_net.c
  19 +++ b/drivers/of/of_net.c
  20 @@ -12,6 +12,7 @@
  21  #include <linux/export.h>
  22  #include <linux/device.h>
  23  #include <linux/nvmem-consumer.h>
  24 +#include <linux/mtd/mtd.h>
  25
  26  /**
  27   * of_get_phy_mode - Get phy mode for given device_node
  28 @@ -95,6 +96,52 @@ static int of_get_mac_addr_nvmem(struct
  29         return 0;
  30  }
  31
  32 +static int of_get_mac_address_mtd(struct device_node *np, u8 *addr)
  33 +{
  34 +#ifdef CONFIG_MTD
  35 +       struct platform_device *pdev = of_find_device_by_node(np);
  36 +       struct device_node *mtd_np = NULL;
  37 +       size_t retlen;
  38 +       int size, ret;
  39 +       struct mtd_info *mtd;
  40 +       const char *part;
  41 +       const __be32 *list;
  42 +       phandle phandle;
  43 +       u8 mac[ETH_ALEN];
  44 +
  45 +       list = of_get_property(np, "mtd-mac-address", &size);
  46 +       if (!list || (size != (2 * sizeof(*list))))
  47 +               return -ENODEV;
  48 +
  49 +       phandle = be32_to_cpup(list++);
  50 +       if (phandle)
  51 +               mtd_np = of_find_node_by_phandle(phandle);
  52 +
  53 +       if (!mtd_np)
  54 +               return -ENODEV;
  55 +
  56 +       part = of_get_property(mtd_np, "label", NULL);
  57 +       if (!part)
  58 +               part = mtd_np->name;
  59 +
  60 +       mtd = get_mtd_device_nm(part);
  61 +       if (IS_ERR(mtd))
  62 +               return -ENODEV;
  63 +
  64 +       ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac);
  65 +       put_mtd_device(mtd);
  66 +
  67 +       if (!is_valid_ether_addr(mac))
  68 +               return -EINVAL;
  69 +
  70 +       memcpy(addr, mac, ETH_ALEN);
  71 +
  72 +       return 0;
  73 +#endif
  74 +       return -EINVAL;
  75 +}
  76 +
  77 +
  78  /**
  79   * Search the device tree for the best MAC address to use.  'mac-address' is
  80   * checked first, because that is supposed to contain to "most recent" MAC
  81 @@ -115,6 +161,10 @@ static int of_get_mac_addr_nvmem(struct
  82   * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
  83   * but is all zeros.
  84   *
  85 + *
  86 + * If a mtd-mac-address property exists, try to fetch the MAC address from the
  87 + * specified mtd device.
  88 + *
  89   * Return: 0 on success and errno in case of error.
  90  */
  91  int of_get_mac_address(struct device_node *np, u8 *addr)
  92 @@ -136,6 +186,10 @@ int of_get_mac_address(struct device_nod
  93         if (!ret)
  94                 return 0;
  95
  96 +       ret = of_get_mac_address_mtd(np, addr);
  97 +       if (!ret)
  98 +               return 0;
  99 +
 100         return of_get_mac_addr_nvmem(np, addr);
 101  }
 102  EXPORT_SYMBOL(of_get_mac_address);