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 #ifdef CONFIG_NL80211_TESTMODE
78 	dev->test.mtd_name = devm_kstrdup(dev->dev, part, GFP_KERNEL);
79 	dev->test.mtd_offset = offset;
80 #endif
81 
82 out_put_node:
83 	of_node_put(np);
84 	return ret;
85 #else
86 	return -ENOENT;
87 #endif
88 }
89 
90 void
91 mt76_eeprom_override(struct mt76_dev *dev)
92 {
93 #ifdef CONFIG_OF
94 	struct device_node *np = dev->dev->of_node;
95 	const u8 *mac = NULL;
96 
97 	if (np)
98 		mac = of_get_mac_address(np);
99 	if (!IS_ERR_OR_NULL(mac))
100 		ether_addr_copy(dev->macaddr, mac);
101 #endif
102 
103 	if (!is_valid_ether_addr(dev->macaddr)) {
104 		eth_random_addr(dev->macaddr);
105 		dev_info(dev->dev,
106 			 "Invalid MAC address, using random address %pM\n",
107 			 dev->macaddr);
108 	}
109 }
110 EXPORT_SYMBOL_GPL(mt76_eeprom_override);
111 
112 int
113 mt76_eeprom_init(struct mt76_dev *dev, int len)
114 {
115 	dev->eeprom.size = len;
116 	dev->eeprom.data = devm_kzalloc(dev->dev, len, GFP_KERNEL);
117 	if (!dev->eeprom.data)
118 		return -ENOMEM;
119 
120 	return !mt76_get_of_eeprom(dev, len);
121 }
122 EXPORT_SYMBOL_GPL(mt76_eeprom_init);
123