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android-kvm / linux / a80a8461868905823609be97f91776a26befe839 / . / drivers / nvmem / nintendo-otp.c
blob: 33961b17f9f1fc9146ab67abd86dd6a28edf7169 [file] [log] [blame]
Emmanuel Gil Peyrot3683b762021-08-10 16:30:36 +0100[diff] [blame]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/mod_devicetable.h>
19#include <linux/nvmem-provider.h>
20#include <linux/of_device.h>
21#include <linux/platform_device.h>
22
23#define HW_OTPCMD 0
24#define HW_OTPDATA 4
25#define OTP_READ 0x80000000
26#define BANK_SIZE 128
27#define WORD_SIZE 4
28
29struct nintendo_otp_priv {
30 void __iomem *regs;
31};
32
33struct nintendo_otp_devtype_data {
34 const char *name;
35 unsigned int num_banks;
36};
37
38static const struct nintendo_otp_devtype_data hollywood_otp_data = {
39 .name = "wii-otp",
40 .num_banks = 1,
41};
42
43static const struct nintendo_otp_devtype_data latte_otp_data = {
44 .name = "wiiu-otp",
45 .num_banks = 8,
46};
47
48static int nintendo_otp_reg_read(void *context,
49 unsigned int reg, void *_val, size_t bytes)
50{
51 struct nintendo_otp_priv *priv = context;
52 u32 *val = _val;
53 int words = bytes / WORD_SIZE;
54 u32 bank, addr;
55
56 while (words--) {
57 bank = (reg / BANK_SIZE) << 8;
58 addr = (reg / WORD_SIZE) % (BANK_SIZE / WORD_SIZE);
59 iowrite32be(OTP_READ | bank | addr, priv->regs + HW_OTPCMD);
60 *val++ = ioread32be(priv->regs + HW_OTPDATA);
61 reg += WORD_SIZE;
62 }
63
64 return 0;
65}
66
67static const struct of_device_id nintendo_otp_of_table[] = {
68 { .compatible = "nintendo,hollywood-otp", .data = &hollywood_otp_data },
69 { .compatible = "nintendo,latte-otp", .data = &latte_otp_data },
70 {/* sentinel */},
71};
72MODULE_DEVICE_TABLE(of, nintendo_otp_of_table);
73
74static int nintendo_otp_probe(struct platform_device *pdev)
75{
76 struct device *dev = &pdev->dev;
77 const struct of_device_id *of_id =
78 of_match_device(nintendo_otp_of_table, dev);
79 struct resource *res;
80 struct nvmem_device *nvmem;
81 struct nintendo_otp_priv *priv;
82
83 struct nvmem_config config = {
84 .stride = WORD_SIZE,
85 .word_size = WORD_SIZE,
86 .reg_read = nintendo_otp_reg_read,
87 .read_only = true,
88 .root_only = true,
89 };
90
91 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
92 if (!priv)
93 return -ENOMEM;
94
95 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
96 priv->regs = devm_ioremap_resource(dev, res);
97 if (IS_ERR(priv->regs))
98 return PTR_ERR(priv->regs);
99
100 if (of_id->data) {
101 const struct nintendo_otp_devtype_data *data = of_id->data;
102 config.name = data->name;
103 config.size = data->num_banks * BANK_SIZE;
104 }
105
106 config.dev = dev;
107 config.priv = priv;
108
109 nvmem = devm_nvmem_register(dev, &config);
110
111 return PTR_ERR_OR_ZERO(nvmem);
112}
113
114static struct platform_driver nintendo_otp_driver = {
115 .probe = nintendo_otp_probe,
116 .driver = {
117 .name = "nintendo-otp",
118 .of_match_table = nintendo_otp_of_table,
119 },
120};
121module_platform_driver(nintendo_otp_driver);
122MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
123MODULE_DESCRIPTION("Nintendo Wii and Wii U OTP driver");
124MODULE_LICENSE("GPL v2");