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

   1 /*
   2  * Copyright (C) 2016 Felix Fietkau <nbd@nbd.name>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #include <linux/of.h>
  17 #include <linux/of_net.h>
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/partitions.h>
  20 #include <linux/etherdevice.h>
  21 #include "mt76.h"
  22
  23 static int
  24 mt76_get_of_eeprom(struct mt76_dev *dev, int len)
  25 {
  26 #if defined(CONFIG_OF) && defined(CONFIG_MTD)
  27         struct device_node *np = dev->dev->of_node;
  28         struct mtd_info *mtd;
  29         const __be32 *list;
  30         const char *part;
  31         phandle phandle;
  32         int offset = 0;
  33         int size;
  34         size_t retlen;
  35         int ret;
  36
  37         if (!np)
  38                 return -ENOENT;
  39
  40         list = of_get_property(np, "mediatek,mtd-eeprom", &size);
  41         if (!list)
  42                 return -ENOENT;
  43
  44         phandle = be32_to_cpup(list++);
  45         if (!phandle)
  46                 return -ENOENT;
  47
  48         np = of_find_node_by_phandle(phandle);
  49         if (!np)
  50                 return -EINVAL;
  51
  52         part = of_get_property(np, "label", NULL);
  53         if (!part)
  54                 part = np->name;
  55
  56         mtd = get_mtd_device_nm(part);
  57         if (IS_ERR(mtd)) {
  58                 ret =  PTR_ERR(mtd);
  59                 goto out_put_node;
  60         }
  61
  62         if (size <= sizeof(*list)) {
  63                 ret = -EINVAL;
  64                 goto out_put_node;
  65         }
  66
  67         offset = be32_to_cpup(list);
  68         ret = mtd_read(mtd, offset, len, &retlen, dev->eeprom.data);
  69         put_mtd_device(mtd);
  70         if (ret)
  71                 goto out_put_node;
  72
  73         if (retlen < len) {
  74                 ret = -EINVAL;
  75                 goto out_put_node;
  76         }
  77
  78 out_put_node:
  79         of_node_put(np);
  80         return ret;
  81 #else
  82         return -ENOENT;
  83 #endif
  84 }
  85
  86 void
  87 mt76_eeprom_override(struct mt76_dev *dev)
  88 {
  89 #ifdef CONFIG_OF
  90         struct device_node *np = dev->dev->of_node;
  91         const u8 *mac;
  92
  93         if (!np)
  94                 return;
  95
  96         mac = of_get_mac_address(np);
  97         if (!IS_ERR(mac))
  98                 memcpy(dev->macaddr, mac, ETH_ALEN);
  99 #endif
 100
 101         if (!is_valid_ether_addr(dev->macaddr)) {
 102                 eth_random_addr(dev->macaddr);
 103                 dev_info(dev->dev,
 104                          "Invalid MAC address, using random address %pM\n",
 105                          dev->macaddr);
 106         }
 107 }
 108 EXPORT_SYMBOL_GPL(mt76_eeprom_override);
 109
 110 int
 111 mt76_eeprom_init(struct mt76_dev *dev, int len)
 112 {
 113         dev->eeprom.size = len;
 114         dev->eeprom.data = devm_kzalloc(dev->dev, len, GFP_KERNEL);
 115         if (!dev->eeprom.data)
 116                 return -ENOMEM;
 117
 118         return !mt76_get_of_eeprom(dev, len);
 119 }
 120 EXPORT_SYMBOL_GPL(mt76_eeprom_init);