acrn-kernel/drivers/nvmem/nintendo-otp.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Nintendo Wii and Wii U OTP driver
*
* This is a driver exposing the OTP of a Nintendo Wii or Wii U console.
*
* This memory contains common and per-console keys, signatures and
* related data required to access peripherals.
*
* Based on reversed documentation from https://wiiubrew.org/wiki/Hardware/OTP
*
* Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
*/
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/nvmem-provider.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#define HW_OTPCMD 0
#define HW_OTPDATA 4
#define OTP_READ 0x80000000
#define BANK_SIZE 128
#define WORD_SIZE 4
struct nintendo_otp_priv {
void __iomem *regs;
};
struct nintendo_otp_devtype_data {
const char *name;
unsigned int num_banks;
};
static const struct nintendo_otp_devtype_data hollywood_otp_data = {
.name = "wii-otp",
.num_banks = 1,
};
static const struct nintendo_otp_devtype_data latte_otp_data = {
.name = "wiiu-otp",
.num_banks = 8,
};
static int nintendo_otp_reg_read(void *context,
unsigned int reg, void *_val, size_t bytes)
{
struct nintendo_otp_priv *priv = context;
u32 *val = _val;
int words = bytes / WORD_SIZE;
u32 bank, addr;
while (words--) {
bank = (reg / BANK_SIZE) << 8;
addr = (reg / WORD_SIZE) % (BANK_SIZE / WORD_SIZE);
iowrite32be(OTP_READ | bank | addr, priv->regs + HW_OTPCMD);
*val++ = ioread32be(priv->regs + HW_OTPDATA);
reg += WORD_SIZE;
}
return 0;
}
static const struct of_device_id nintendo_otp_of_table[] = {
{ .compatible = "nintendo,hollywood-otp", .data = &hollywood_otp_data },
{ .compatible = "nintendo,latte-otp", .data = &latte_otp_data },
{/* sentinel */},
};
MODULE_DEVICE_TABLE(of, nintendo_otp_of_table);
static int nintendo_otp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct of_device_id *of_id =
of_match_device(nintendo_otp_of_table, dev);
struct resource *res;
struct nvmem_device *nvmem;
struct nintendo_otp_priv *priv;
struct nvmem_config config = {
.stride = WORD_SIZE,
.word_size = WORD_SIZE,
.reg_read = nintendo_otp_reg_read,
.read_only = true,
.root_only = true,
};
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->regs = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->regs))
return PTR_ERR(priv->regs);
if (of_id->data) {
const struct nintendo_otp_devtype_data *data = of_id->data;
config.name = data->name;
config.size = data->num_banks * BANK_SIZE;
}
config.dev = dev;
config.priv = priv;
nvmem = devm_nvmem_register(dev, &config);
return PTR_ERR_OR_ZERO(nvmem);
}
static struct platform_driver nintendo_otp_driver = {
.probe = nintendo_otp_probe,
.driver = {
.name = "nintendo-otp",
.of_match_table = nintendo_otp_of_table,
},
};
module_platform_driver(nintendo_otp_driver);
MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
MODULE_DESCRIPTION("Nintendo Wii and Wii U OTP driver");
MODULE_LICENSE("GPL v2");