target/linux/generic/patches-4.9/681-NET-add-of_get_mac_address_mtd.patch

   1 From: John Crispin <blogic@openwrt.org>
   2 Date: Sun, 27 Jul 2014 09:40:01 +0100
   3 Subject: NET: add mtd-mac-address support to of_get_mac_address()
   4
   5 Many embedded devices have information such as mac addresses stored inside mtd
   6 devices. This patch allows us to add a property inside a node describing a
   7 network interface. The new property points at a mtd partition with an offset
   8 where the mac address can be found.
   9
  10 Signed-off-by: John Crispin <blogic@openwrt.org>
  11 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  12 ---
  13  drivers/of/of_net.c    |   37 +++++++++++++++++++++++++++++++++++++
  14  include/linux/of_net.h |    1 +
  15  2 files changed, 38 insertions(+)
  16
  17 --- a/drivers/of/of_net.c
  18 +++ b/drivers/of/of_net.c
  19 @@ -10,6 +10,7 @@
  20  #include <linux/of_net.h>
  21  #include <linux/phy.h>
  22  #include <linux/export.h>
  23 +#include <linux/mtd/mtd.h>
  24
  25  /**
  26   * of_get_phy_mode - Get phy mode for given device_node
  27 @@ -38,7 +39,7 @@ int of_get_phy_mode(struct device_node *
  28  }
  29  EXPORT_SYMBOL_GPL(of_get_phy_mode);
  30
  31 -static const void *of_get_mac_addr(struct device_node *np, const char *name)
  32 +static void *of_get_mac_addr(struct device_node *np, const char *name)
  33  {
  34         struct property *pp = of_find_property(np, name, NULL);
  35
  36 @@ -47,6 +48,73 @@ static const void *of_get_mac_addr(struc
  37         return NULL;
  38  }
  39
  40 +static const void *of_get_mac_address_mtd(struct device_node *np)
  41 +{
  42 +#ifdef CONFIG_MTD
  43 +       struct device_node *mtd_np = NULL;
  44 +       struct property *prop;
  45 +       size_t retlen;
  46 +       int size, ret;
  47 +       struct mtd_info *mtd;
  48 +       const char *part;
  49 +       const __be32 *list;
  50 +       phandle phandle;
  51 +       u32 mac_inc = 0;
  52 +       u8 mac[ETH_ALEN];
  53 +       void *addr;
  54 +
  55 +       list = of_get_property(np, "mtd-mac-address", &size);
  56 +       if (!list || (size != (2 * sizeof(*list))))
  57 +               return NULL;
  58 +
  59 +       phandle = be32_to_cpup(list++);
  60 +       if (phandle)
  61 +               mtd_np = of_find_node_by_phandle(phandle);
  62 +
  63 +       if (!mtd_np)
  64 +               return NULL;
  65 +
  66 +       part = of_get_property(mtd_np, "label", NULL);
  67 +       if (!part)
  68 +               part = mtd_np->name;
  69 +
  70 +       mtd = get_mtd_device_nm(part);
  71 +       if (IS_ERR(mtd))
  72 +               return NULL;
  73 +
  74 +       ret = mtd_read(mtd, be32_to_cpup(list), 6, &retlen, mac);
  75 +       put_mtd_device(mtd);
  76 +
  77 +       if (!of_property_read_u32(np, "mtd-mac-address-increment", &mac_inc))
  78 +               mac[5] += mac_inc;
  79 +
  80 +       if (!is_valid_ether_addr(mac))
  81 +               return NULL;
  82 +
  83 +       addr = of_get_mac_addr(np, "mac-address");
  84 +       if (addr) {
  85 +               memcpy(addr, mac, ETH_ALEN);
  86 +               return addr;
  87 +       }
  88 +
  89 +       prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  90 +       if (!prop)
  91 +               return NULL;
  92 +
  93 +       prop->name = "mac-address";
  94 +       prop->length = ETH_ALEN;
  95 +       prop->value = kmemdup(mac, ETH_ALEN, GFP_KERNEL);
  96 +       if (!prop->value || of_add_property(np, prop))
  97 +               goto free;
  98 +
  99 +       return prop->value;
 100 +free:
 101 +       kfree(prop->value);
 102 +       kfree(prop);
 103 +#endif
 104 +       return NULL;
 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 @@ -64,11 +132,18 @@ static const void *of_get_mac_addr(struc
 111   * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
 112   * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 113   * but is all zeros.
 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  const void *of_get_mac_address(struct device_node *np)
 119  {
 120         const void *addr;
 121
 122 +       addr = of_get_mac_address_mtd(np);
 123 +       if (addr)
 124 +               return addr;
 125 +
 126         addr = of_get_mac_addr(np, "mac-address");
 127         if (addr)
 128                 return addr;