target/linux/generic/pending-5.4/681-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 diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
  19 index 6e411821583e..f072e2509cc9 100644
  20 --- a/drivers/of/of_net.c
  21 +++ b/drivers/of/of_net.c
  22 @@ -11,6 +11,7 @@
  23  #include <linux/phy.h>
  24  #include <linux/export.h>
  25  #include <linux/device.h>
  26 +#include <linux/mtd/mtd.h>
  27
  28  /**
  29   * of_get_phy_mode - Get phy mode for given device_node
  30 @@ -45,7 +46,7 @@ int of_get_phy_mode(struct device_node *np, phy_interface_t *interface)
  31  }
  32  EXPORT_SYMBOL_GPL(of_get_phy_mode);
  33
  34 -static const void *of_get_mac_addr(struct device_node *np, const char *name)
  35 +static void *of_get_mac_addr(struct device_node *np, const char *name)
  36  {
  37         struct property *pp = of_find_property(np, name, NULL);
  38
  39 @@ -78,6 +79,70 @@ static const void *of_get_mac_addr_nvmem(struct device_node *np)
  40         return mac;
  41  }
  42
  43 +static const void *of_get_mac_address_mtd(struct device_node *np)
  44 +{
  45 +#ifdef CONFIG_MTD
  46 +       struct device_node *mtd_np = NULL;
  47 +       struct property *prop;
  48 +       size_t retlen;
  49 +       int size, ret;
  50 +       struct mtd_info *mtd;
  51 +       const char *part;
  52 +       const __be32 *list;
  53 +       phandle phandle;
  54 +       u8 mac[ETH_ALEN];
  55 +       void *addr;
  56 +
  57 +       list = of_get_property(np, "mtd-mac-address", &size);
  58 +       if (!list || (size != (2 * sizeof(*list))))
  59 +               return NULL;
  60 +
  61 +       phandle = be32_to_cpup(list++);
  62 +       if (phandle)
  63 +               mtd_np = of_find_node_by_phandle(phandle);
  64 +
  65 +       if (!mtd_np)
  66 +               return NULL;
  67 +
  68 +       part = of_get_property(mtd_np, "label", NULL);
  69 +       if (!part)
  70 +               part = mtd_np->name;
  71 +
  72 +       mtd = get_mtd_device_nm(part);
  73 +       if (IS_ERR(mtd))
  74 +               return NULL;
  75 +
  76 +       ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac);
  77 +       put_mtd_device(mtd);
  78 +
  79 +       if (!is_valid_ether_addr(mac))
  80 +               return NULL;
  81 +
  82 +       addr = of_get_mac_addr(np, "mac-address");
  83 +       if (addr) {
  84 +               memcpy(addr, mac, ETH_ALEN);
  85 +               return addr;
  86 +       }
  87 +
  88 +       prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  89 +       if (!prop)
  90 +               return NULL;
  91 +
  92 +       prop->name = "mac-address";
  93 +       prop->length = ETH_ALEN;
  94 +       prop->value = kmemdup(mac, ETH_ALEN, GFP_KERNEL);
  95 +       if (!prop->value || of_add_property(np, prop))
  96 +               goto free;
  97 +
  98 +       return prop->value;
  99 +free:
 100 +       kfree(prop->value);
 101 +       kfree(prop);
 102 +#endif
 103 +       return NULL;
 104 +}
 105 +
 106 +
 107  /**
 108   * Search the device tree for the best MAC address to use.  'mac-address' is
 109   * checked first, because that is supposed to contain to "most recent" MAC
 110 @@ -98,6 +163,10 @@ static const void *of_get_mac_addr_nvmem(struct device_node *np)
 111   * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 112   * but is all zeros.
 113   *
 114 + *
 115 + * If a mtd-mac-address property exists, try to fetch the MAC address from the
 116 + * specified mtd device, and store it as a 'mac-address' property
 117 + *
 118   * Return: Will be a valid pointer on success and ERR_PTR in case of error.
 119  */
 120  const void *of_get_mac_address(struct device_node *np)
 121 @@ -116,6 +185,10 @@ const void *of_get_mac_address(struct device_node *np)
 122         if (addr)
 123                 return addr;
 124
 125 +       addr = of_get_mac_address_mtd(np);
 126 +       if (addr)
 127 +               return addr;
 128 +
 129         return of_get_mac_addr_nvmem(np);
 130  }
 131  EXPORT_SYMBOL(of_get_mac_address);
 132 --
 133 2.30.2
 134