target/linux/generic/backport-5.10/732-net-next-2-of-net-fix-of_get_mac_addr_nvmem-for-non-platform-devices.patch

   1 From f10843e04a075202dbb39dfcee047e3a2fdf5a8d Mon Sep 17 00:00:00 2001
   2 From: Michael Walle <michael@walle.cc>
   3 Date: Mon, 12 Apr 2021 19:47:18 +0200
   4 Subject: of: net: fix of_get_mac_addr_nvmem() for non-platform devices
   5
   6 of_get_mac_address() already supports fetching the MAC address by an
   7 nvmem provider. But until now, it was just working for platform devices.
   8 Esp. it was not working for DSA ports and PCI devices. It gets more
   9 common that PCI devices have a device tree binding since SoCs contain
  10 integrated root complexes.
  11
  12 Use the nvmem of_* binding to fetch the nvmem cells by a struct
  13 device_node. We still have to try to read the cell by device first
  14 because there might be a nvmem_cell_lookup associated with that device.
  15
  16 Signed-off-by: Michael Walle <michael@walle.cc>
  17 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
  18 Signed-off-by: David S. Miller <davem@davemloft.net>
  19 ---
  20  drivers/of/of_net.c | 35 ++++++++++++++++++++++++++++++-----
  21  1 file changed, 30 insertions(+), 5 deletions(-)
  22
  23 --- a/drivers/of/of_net.c
  24 +++ b/drivers/of/of_net.c
  25 @@ -11,6 +11,7 @@
  26  #include <linux/phy.h>
  27  #include <linux/export.h>
  28  #include <linux/device.h>
  29 +#include <linux/nvmem-consumer.h>
  30
  31  /**
  32   * of_get_phy_mode - Get phy mode for given device_node
  33 @@ -59,15 +60,39 @@ static int of_get_mac_addr(struct device
  34  static int of_get_mac_addr_nvmem(struct device_node *np, u8 *addr)
  35  {
  36         struct platform_device *pdev = of_find_device_by_node(np);
  37 +       struct nvmem_cell *cell;
  38 +       const void *mac;
  39 +       size_t len;
  40         int ret;
  41
  42 -       if (!pdev)
  43 -               return -ENODEV;
  44 +       /* Try lookup by device first, there might be a nvmem_cell_lookup
  45 +        * associated with a given device.
  46 +        */
  47 +       if (pdev) {
  48 +               ret = nvmem_get_mac_address(&pdev->dev, addr);
  49 +               put_device(&pdev->dev);
  50 +               return ret;
  51 +       }
  52 +
  53 +       cell = of_nvmem_cell_get(np, "mac-address");
  54 +       if (IS_ERR(cell))
  55 +               return PTR_ERR(cell);
  56 +
  57 +       mac = nvmem_cell_read(cell, &len);
  58 +       nvmem_cell_put(cell);
  59 +
  60 +       if (IS_ERR(mac))
  61 +               return PTR_ERR(mac);
  62 +
  63 +       if (len != ETH_ALEN || !is_valid_ether_addr(mac)) {
  64 +               kfree(mac);
  65 +               return -EINVAL;
  66 +       }
  67
  68 -       ret = nvmem_get_mac_address(&pdev->dev, addr);
  69 -       put_device(&pdev->dev);
  70 +       memcpy(addr, mac, ETH_ALEN);
  71 +       kfree(mac);
  72
  73 -       return ret;
  74 +       return 0;
  75  }
  76
  77  /**