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 		ether_addr_copy(dev->macaddr, mac);
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);
121