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       1                 :            : // SPDX-License-Identifier: GPL-2.0-only
       2                 :            : /*
       3                 :            :  * OF helpers for network devices.
       4                 :            :  *
       5                 :            :  * Initially copied out of arch/powerpc/kernel/prom_parse.c
       6                 :            :  */
       7                 :            : #include <linux/etherdevice.h>
       8                 :            : #include <linux/kernel.h>
       9                 :            : #include <linux/of_net.h>
      10                 :            : #include <linux/of_platform.h>
      11                 :            : #include <linux/phy.h>
      12                 :            : #include <linux/export.h>
      13                 :            : #include <linux/device.h>
      14                 :            : 
      15                 :            : /**
      16                 :            :  * of_get_phy_mode - Get phy mode for given device_node
      17                 :            :  * @np: Pointer to the given device_node
      18                 :            :  *
      19                 :            :  * The function gets phy interface string from property 'phy-mode' or
      20                 :            :  * 'phy-connection-type', and return its index in phy_modes table, or errno in
      21                 :            :  * error case.
      22                 :            :  */
      23                 :          0 : int of_get_phy_mode(struct device_node *np)
      24                 :            : {
      25                 :            :         const char *pm;
      26                 :            :         int err, i;
      27                 :            : 
      28                 :          0 :         err = of_property_read_string(np, "phy-mode", &pm);
      29         [ #  # ]:          0 :         if (err < 0)
      30                 :          0 :                 err = of_property_read_string(np, "phy-connection-type", &pm);
      31         [ #  # ]:          0 :         if (err < 0)
      32                 :            :                 return err;
      33                 :            : 
      34         [ #  # ]:          0 :         for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
      35   [ #  #  #  # ]:          0 :                 if (!strcasecmp(pm, phy_modes(i)))
      36                 :          0 :                         return i;
      37                 :            : 
      38                 :            :         return -ENODEV;
      39                 :            : }
      40                 :            : EXPORT_SYMBOL_GPL(of_get_phy_mode);
      41                 :            : 
      42                 :          0 : static const void *of_get_mac_addr(struct device_node *np, const char *name)
      43                 :            : {
      44                 :          0 :         struct property *pp = of_find_property(np, name, NULL);
      45                 :            : 
      46   [ #  #  #  #  :          0 :         if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
                   #  # ]
      47                 :          0 :                 return pp->value;
      48                 :            :         return NULL;
      49                 :            : }
      50                 :            : 
      51                 :          0 : static const void *of_get_mac_addr_nvmem(struct device_node *np)
      52                 :            : {
      53                 :            :         int ret;
      54                 :            :         const void *mac;
      55                 :            :         u8 nvmem_mac[ETH_ALEN];
      56                 :          0 :         struct platform_device *pdev = of_find_device_by_node(np);
      57                 :            : 
      58         [ #  # ]:          0 :         if (!pdev)
      59                 :            :                 return ERR_PTR(-ENODEV);
      60                 :            : 
      61                 :          0 :         ret = nvmem_get_mac_address(&pdev->dev, &nvmem_mac);
      62         [ #  # ]:          0 :         if (ret) {
      63                 :          0 :                 put_device(&pdev->dev);
      64                 :          0 :                 return ERR_PTR(ret);
      65                 :            :         }
      66                 :            : 
      67                 :          0 :         mac = devm_kmemdup(&pdev->dev, nvmem_mac, ETH_ALEN, GFP_KERNEL);
      68                 :          0 :         put_device(&pdev->dev);
      69         [ #  # ]:          0 :         if (!mac)
      70                 :            :                 return ERR_PTR(-ENOMEM);
      71                 :            : 
      72                 :          0 :         return mac;
      73                 :            : }
      74                 :            : 
      75                 :            : /**
      76                 :            :  * Search the device tree for the best MAC address to use.  'mac-address' is
      77                 :            :  * checked first, because that is supposed to contain to "most recent" MAC
      78                 :            :  * address. If that isn't set, then 'local-mac-address' is checked next,
      79                 :            :  * because that is the default address. If that isn't set, then the obsolete
      80                 :            :  * 'address' is checked, just in case we're using an old device tree. If any
      81                 :            :  * of the above isn't set, then try to get MAC address from nvmem cell named
      82                 :            :  * 'mac-address'.
      83                 :            :  *
      84                 :            :  * Note that the 'address' property is supposed to contain a virtual address of
      85                 :            :  * the register set, but some DTS files have redefined that property to be the
      86                 :            :  * MAC address.
      87                 :            :  *
      88                 :            :  * All-zero MAC addresses are rejected, because those could be properties that
      89                 :            :  * exist in the device tree, but were not set by U-Boot.  For example, the
      90                 :            :  * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
      91                 :            :  * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
      92                 :            :  * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
      93                 :            :  * but is all zeros.
      94                 :            :  *
      95                 :            :  * Return: Will be a valid pointer on success and ERR_PTR in case of error.
      96                 :            : */
      97                 :          0 : const void *of_get_mac_address(struct device_node *np)
      98                 :            : {
      99                 :            :         const void *addr;
     100                 :            : 
     101                 :          0 :         addr = of_get_mac_addr(np, "mac-address");
     102         [ #  # ]:          0 :         if (addr)
     103                 :            :                 return addr;
     104                 :            : 
     105                 :          0 :         addr = of_get_mac_addr(np, "local-mac-address");
     106         [ #  # ]:          0 :         if (addr)
     107                 :            :                 return addr;
     108                 :            : 
     109                 :          0 :         addr = of_get_mac_addr(np, "address");
     110         [ #  # ]:          0 :         if (addr)
     111                 :            :                 return addr;
     112                 :            : 
     113                 :          0 :         return of_get_mac_addr_nvmem(np);
     114                 :            : }
     115                 :            : EXPORT_SYMBOL(of_get_mac_address);