drivers/net/wireless/mediatek/mt76/eeprom.c

   1 // SPDX-License-Identifier: ISC
   2 /*
   3  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
   4  */
   5 #include <linux/of.h>
   6 #include <linux/of_net.h>
   7 #include <linux/mtd/mtd.h>
   8 #include <linux/mtd/partitions.h>
   9 #include <linux/etherdevice.h>
  10 #include "mt76.h"
  11
  12 static int
  13 mt76_get_of_eeprom(struct mt76_dev *dev, int len)
  14 {
  15 #if defined(CONFIG_OF) && defined(CONFIG_MTD)
  16         struct device_node *np = dev->dev->of_node;
  17         struct mtd_info *mtd;
  18         const __be32 *list;
  19         const char *part;
  20         phandle phandle;
  21         int offset = 0;
  22         int size;
  23         size_t retlen;
  24         int ret;
  25
  26         if (!np)
  27                 return -ENOENT;
  28
  29         list = of_get_property(np, "mediatek,mtd-eeprom", &size);
  30         if (!list)
  31                 return -ENOENT;
  32
  33         phandle = be32_to_cpup(list++);
  34         if (!phandle)
  35                 return -ENOENT;
  36
  37         np = of_find_node_by_phandle(phandle);
  38         if (!np)
  39                 return -EINVAL;
  40
  41         part = of_get_property(np, "label", NULL);
  42         if (!part)
  43                 part = np->name;
  44
  45         mtd = get_mtd_device_nm(part);
  46         if (IS_ERR(mtd)) {
  47                 ret =  PTR_ERR(mtd);
  48                 goto out_put_node;
  49         }
  50
  51         if (size <= sizeof(*list)) {
  52                 ret = -EINVAL;
  53                 goto out_put_node;
  54         }
  55
  56         offset = be32_to_cpup(list);
  57         ret = mtd_read(mtd, offset, len, &retlen, dev->eeprom.data);
  58         put_mtd_device(mtd);
  59         if (ret)
  60                 goto out_put_node;
  61
  62         if (retlen < len) {
  63                 ret = -EINVAL;
  64                 goto out_put_node;
  65         }
  66
  67         if (of_property_read_bool(dev->dev->of_node, "big-endian")) {
  68                 u8 *data = (u8 *)dev->eeprom.data;
  69                 int i;
  70
  71                 /* convert eeprom data in Little Endian */
  72                 for (i = 0; i < round_down(len, 2); i += 2)
  73                         put_unaligned_le16(get_unaligned_be16(&data[i]),
  74                                            &data[i]);
  75         }
  76
  77 out_put_node:
  78         of_node_put(np);
  79         return ret;
  80 #else
  81         return -ENOENT;
  82 #endif
  83 }
  84
  85 void
  86 mt76_eeprom_override(struct mt76_dev *dev)
  87 {
  88 #ifdef CONFIG_OF
  89         struct device_node *np = dev->dev->of_node;
  90         const u8 *mac = NULL;
  91
  92         if (np)
  93                 mac = of_get_mac_address(np);
  94         if (!IS_ERR_OR_NULL(mac))
  95                 ether_addr_copy(dev->macaddr, mac);
  96 #endif
  97
  98         if (!is_valid_ether_addr(dev->macaddr)) {
  99                 eth_random_addr(dev->macaddr);
 100                 dev_info(dev->dev,
 101                          "Invalid MAC address, using random address %pM\n",
 102                          dev->macaddr);
 103         }
 104 }
 105 EXPORT_SYMBOL_GPL(mt76_eeprom_override);
 106
 107 int
 108 mt76_eeprom_init(struct mt76_dev *dev, int len)
 109 {
 110         dev->eeprom.size = len;
 111         dev->eeprom.data = devm_kzalloc(dev->dev, len, GFP_KERNEL);
 112         if (!dev->eeprom.data)
 113                 return -ENOMEM;
 114
 115         return !mt76_get_of_eeprom(dev, len);
 116 }
 117 EXPORT_SYMBOL_GPL(mt76_eeprom_init);