| 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 | |
| 29 | struct nintendo_otp_priv { |
| 30 | void __iomem *regs; |
| 31 | }; |
| 32 | |
| 33 | struct nintendo_otp_devtype_data { |
| 34 | const char *name; |
| 35 | unsigned int num_banks; |
| 36 | }; |
| 37 | |
| 38 | static const struct nintendo_otp_devtype_data hollywood_otp_data = { |
| 39 | .name = "wii-otp", |
| 40 | .num_banks = 1, |
| 41 | }; |
| 42 | |
| 43 | static const struct nintendo_otp_devtype_data latte_otp_data = { |
| 44 | .name = "wiiu-otp", |
| 45 | .num_banks = 8, |
| 46 | }; |
| 47 | |
| 48 | static 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 | |
| 67 | static 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 | }; |
| 72 | MODULE_DEVICE_TABLE(of, nintendo_otp_of_table); |
| 73 | |
| 74 | static 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 nvmem_device *nvmem; |
| 80 | struct nintendo_otp_priv *priv; |
| 81 | |
| 82 | struct nvmem_config config = { |
| 83 | .stride = WORD_SIZE, |
| 84 | .word_size = WORD_SIZE, |
| 85 | .reg_read = nintendo_otp_reg_read, |
| 86 | .read_only = true, |
| 87 | .root_only = true, |
| 88 | }; |
| 89 | |
| 90 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
| 91 | if (!priv) |
| 92 | return -ENOMEM; |
| 93 | |
| 94 | priv->regs = devm_platform_ioremap_resource(pdev, 0); |
| 95 | if (IS_ERR(priv->regs)) |
| 96 | return PTR_ERR(priv->regs); |
| 97 | |
| 98 | if (of_id->data) { |
| 99 | const struct nintendo_otp_devtype_data *data = of_id->data; |
| 100 | config.name = data->name; |
| 101 | config.size = data->num_banks * BANK_SIZE; |
| 102 | } |
| 103 | |
| 104 | config.dev = dev; |
| 105 | config.priv = priv; |
| 106 | |
| 107 | nvmem = devm_nvmem_register(dev, &config); |
| 108 | |
| 109 | return PTR_ERR_OR_ZERO(nvmem); |
| 110 | } |
| 111 | |
| 112 | static struct platform_driver nintendo_otp_driver = { |
| 113 | .probe = nintendo_otp_probe, |
| 114 | .driver = { |
| 115 | .name = "nintendo-otp", |
| 116 | .of_match_table = nintendo_otp_of_table, |
| 117 | }, |
| 118 | }; |
| 119 | module_platform_driver(nintendo_otp_driver); |
| 120 | MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>"); |
| 121 | MODULE_DESCRIPTION("Nintendo Wii and Wii U OTP driver"); |
| 122 | MODULE_LICENSE("GPL v2"); |