1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Nintendo Wii and Wii U OTP driver
4 *
5 * This is a driver exposing the OTP of a Nintendo Wii or Wii U console.
6 *
7 * This memory contains common and per-console keys, signatures and
8 * related data required to access peripherals.
9 *
10 * Based on reversed documentation from https://wiiubrew.org/wiki/Hardware/OTP
11 *
12 * Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
13 */
14
15 #include <linux/device.h>
16 #include <linux/io.h>
17 #include <linux/module.h>
18 #include <linux/nvmem-provider.h>
19 #include <linux/of.h>
20 #include <linux/platform_device.h>
21
22 #define HW_OTPCMD 0
23 #define HW_OTPDATA 4
24 #define OTP_READ 0x80000000
25 #define BANK_SIZE 128
26 #define WORD_SIZE 4
27
28 struct nintendo_otp_priv {
29 void __iomem *regs;
30 };
31
32 struct nintendo_otp_devtype_data {
33 const char *name;
34 unsigned int num_banks;
35 };
36
37 static const struct nintendo_otp_devtype_data hollywood_otp_data = {
38 .name = "wii-otp",
39 .num_banks = 1,
40 };
41
42 static const struct nintendo_otp_devtype_data latte_otp_data = {
43 .name = "wiiu-otp",
44 .num_banks = 8,
45 };
46
nintendo_otp_reg_read(void * context,unsigned int reg,void * _val,size_t bytes)47 static int nintendo_otp_reg_read(void *context,
48 unsigned int reg, void *_val, size_t bytes)
49 {
50 struct nintendo_otp_priv *priv = context;
51 u32 *val = _val;
52 int words = bytes / WORD_SIZE;
53 u32 bank, addr;
54
55 while (words--) {
56 bank = (reg / BANK_SIZE) << 8;
57 addr = (reg / WORD_SIZE) % (BANK_SIZE / WORD_SIZE);
58 iowrite32be(OTP_READ | bank | addr, priv->regs + HW_OTPCMD);
59 *val++ = ioread32be(priv->regs + HW_OTPDATA);
60 reg += WORD_SIZE;
61 }
62
63 return 0;
64 }
65
66 static const struct of_device_id nintendo_otp_of_table[] = {
67 { .compatible = "nintendo,hollywood-otp", .data = &hollywood_otp_data },
68 { .compatible = "nintendo,latte-otp", .data = &latte_otp_data },
69 {/* sentinel */},
70 };
71 MODULE_DEVICE_TABLE(of, nintendo_otp_of_table);
72
nintendo_otp_probe(struct platform_device * pdev)73 static int nintendo_otp_probe(struct platform_device *pdev)
74 {
75 struct device *dev = &pdev->dev;
76 const struct nintendo_otp_devtype_data *data;
77 struct nvmem_device *nvmem;
78 struct nintendo_otp_priv *priv;
79
80 struct nvmem_config config = {
81 .stride = WORD_SIZE,
82 .word_size = WORD_SIZE,
83 .reg_read = nintendo_otp_reg_read,
84 .read_only = true,
85 .root_only = true,
86 };
87
88 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
89 if (!priv)
90 return -ENOMEM;
91
92 priv->regs = devm_platform_ioremap_resource(pdev, 0);
93 if (IS_ERR(priv->regs))
94 return PTR_ERR(priv->regs);
95
96 data = of_device_get_match_data(dev);
97 if (data) {
98 config.name = data->name;
99 config.size = data->num_banks * BANK_SIZE;
100 }
101
102 config.dev = dev;
103 config.priv = priv;
104
105 nvmem = devm_nvmem_register(dev, &config);
106
107 return PTR_ERR_OR_ZERO(nvmem);
108 }
109
110 static struct platform_driver nintendo_otp_driver = {
111 .probe = nintendo_otp_probe,
112 .driver = {
113 .name = "nintendo-otp",
114 .of_match_table = nintendo_otp_of_table,
115 },
116 };
117 module_platform_driver(nintendo_otp_driver);
118 MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
119 MODULE_DESCRIPTION("Nintendo Wii and Wii U OTP driver");
120 MODULE_LICENSE("GPL v2");
121