target/linux/generic/pending-4.19/681-NET-add-of_get_mac_address_mtd.patch

   1 From: John Crispin <blogic@openwrt.org>
   2 Subject: NET: add mtd-mac-address support to of_get_mac_address()
   3
   4 Many embedded devices have information such as mac addresses stored inside mtd
   5 devices. This patch allows us to add a property inside a node describing a
   6 network interface. The new property points at a mtd partition with an offset
   7 where the mac address can be found.
   8
   9 Signed-off-by: John Crispin <blogic@openwrt.org>
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12  drivers/of/of_net.c    |   37 +++++++++++++++++++++++++++++++++++++
  13  include/linux/of_net.h |    1 +
  14  2 files changed, 38 insertions(+)
  15
  16 --- a/drivers/of/of_net.c
  17 +++ b/drivers/of/of_net.c
  18 @@ -10,6 +10,7 @@
  19  #include <linux/of_net.h>
  20  #include <linux/phy.h>
  21  #include <linux/export.h>
  22 +#include <linux/mtd/mtd.h>
  23
  24  /**
  25   * of_get_phy_mode - Get phy mode for given device_node
  26 @@ -38,7 +39,7 @@ int of_get_phy_mode(struct device_node *
  27  }
  28  EXPORT_SYMBOL_GPL(of_get_phy_mode);
  29
  30 -static const void *of_get_mac_addr(struct device_node *np, const char *name)
  31 +static void *of_get_mac_addr(struct device_node *np, const char *name)
  32  {
  33         struct property *pp = of_find_property(np, name, NULL);
  34
  35 @@ -47,6 +48,79 @@ static const void *of_get_mac_addr(struc
  36         return NULL;
  37  }
  38
  39 +static const void *of_get_mac_address_mtd(struct device_node *np)
  40 +{
  41 +#ifdef CONFIG_MTD
  42 +       struct device_node *mtd_np = NULL;
  43 +       struct property *prop;
  44 +       size_t retlen;
  45 +       int size, ret;
  46 +       struct mtd_info *mtd;
  47 +       const char *part;
  48 +       const __be32 *list;
  49 +       phandle phandle;
  50 +       u32 mac_inc = 0;
  51 +       u8 mac[ETH_ALEN];
  52 +       void *addr;
  53 +       u32 inc_idx;
  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-byte", &inc_idx))
  78 +               inc_idx = 5;
  79 +       if (inc_idx > 5)
  80 +               return NULL;
  81 +
  82 +       if (!of_property_read_u32(np, "mtd-mac-address-increment", &mac_inc))
  83 +               mac[inc_idx] += mac_inc;
  84 +
  85 +       if (!is_valid_ether_addr(mac))
  86 +               return NULL;
  87 +
  88 +       addr = of_get_mac_addr(np, "mac-address");
  89 +       if (addr) {
  90 +               memcpy(addr, mac, ETH_ALEN);
  91 +               return addr;
  92 +       }
  93 +
  94 +       prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  95 +       if (!prop)
  96 +               return NULL;
  97 +
  98 +       prop->name = "mac-address";
  99 +       prop->length = ETH_ALEN;
 100 +       prop->value = kmemdup(mac, ETH_ALEN, GFP_KERNEL);
 101 +       if (!prop->value || of_add_property(np, prop))
 102 +               goto free;
 103 +
 104 +       return prop->value;
 105 +free:
 106 +       kfree(prop->value);
 107 +       kfree(prop);
 108 +#endif
 109 +       return NULL;
 110 +}
 111 +
 112  /**
 113   * Search the device tree for the best MAC address to use.  'mac-address' is
 114   * checked first, because that is supposed to contain to "most recent" MAC
 115 @@ -64,11 +138,18 @@ static const void *of_get_mac_addr(struc
 116   * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
 117   * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 118   * but is all zeros.
 119 + *
 120 + * If a mtd-mac-address property exists, try to fetch the MAC address from the
 121 + * specified mtd device, and store it as a 'mac-address' property
 122  */
 123  const void *of_get_mac_address(struct device_node *np)
 124  {
 125         const void *addr;
 126
 127 +       addr = of_get_mac_address_mtd(np);
 128 +       if (addr)
 129 +               return addr;
 130 +
 131         addr = of_get_mac_addr(np, "mac-address");
 132         if (addr)
 133                 return addr;