1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/nvmem/nintendo-otp.c b/drivers/nvmem/nintendo-otp.c
new file mode 100644
index 0000000000..355e7f1fc6
--- /dev/null
+++ b/drivers/nvmem/nintendo-otp.c
@@ -0,0 +1,122 @@
+// 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 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;
+
+	priv->regs = devm_platform_ioremap_resource(pdev, 0);
+	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");