1 files changed, 362 insertions, 0 deletions
diff --git a/drivers/mtd/nand/spi/otp.c b/drivers/mtd/nand/spi/otp.c
new file mode 100644
index 000000000000..ce41bca86ea9
--- /dev/null
+++ b/drivers/mtd/nand/spi/otp.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025, SaluteDevices. All Rights Reserved.
+ *
+ * Author: Martin Kurbanov <mmkurbanov@salutedevices.com>
+ */
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/spinand.h>
+
+/**
+ * spinand_otp_page_size() - Get SPI-NAND OTP page size
+ * @spinand: the spinand device
+ *
+ * Return: the OTP page size.
+ */
+size_t spinand_otp_page_size(struct spinand_device *spinand)
+{
+	struct nand_device *nand = spinand_to_nand(spinand);
+
+	return nanddev_page_size(nand) + nanddev_per_page_oobsize(nand);
+}
+
+static size_t spinand_otp_size(struct spinand_device *spinand,
+			       const struct spinand_otp_layout *layout)
+{
+	return layout->npages * spinand_otp_page_size(spinand);
+}
+
+/**
+ * spinand_fact_otp_size() - Get SPI-NAND factory OTP area size
+ * @spinand: the spinand device
+ *
+ * Return: the OTP size.
+ */
+size_t spinand_fact_otp_size(struct spinand_device *spinand)
+{
+	return spinand_otp_size(spinand, &spinand->fact_otp->layout);
+}
+
+/**
+ * spinand_user_otp_size() - Get SPI-NAND user OTP area size
+ * @spinand: the spinand device
+ *
+ * Return: the OTP size.
+ */
+size_t spinand_user_otp_size(struct spinand_device *spinand)
+{
+	return spinand_otp_size(spinand, &spinand->user_otp->layout);
+}
+
+static int spinand_otp_check_bounds(struct spinand_device *spinand, loff_t ofs,
+				    size_t len,
+				    const struct spinand_otp_layout *layout)
+{
+	if (ofs < 0 || ofs + len > spinand_otp_size(spinand, layout))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int spinand_user_otp_check_bounds(struct spinand_device *spinand,
+					 loff_t ofs, size_t len)
+{
+	return spinand_otp_check_bounds(spinand, ofs, len,
+					&spinand->user_otp->layout);
+}
+
+static int spinand_otp_rw(struct spinand_device *spinand, loff_t ofs,
+			  size_t len, size_t *retlen, u8 *buf, bool is_write,
+			  const struct spinand_otp_layout *layout)
+{
+	struct nand_page_io_req req = {};
+	unsigned long long page;
+	size_t copied = 0;
+	size_t otp_pagesize = spinand_otp_page_size(spinand);
+	int ret;
+
+	if (!len)
+		return 0;
+
+	ret = spinand_otp_check_bounds(spinand, ofs, len, layout);
+	if (ret)
+		return ret;
+
+	ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, CFG_OTP_ENABLE);
+	if (ret)
+		return ret;
+
+	page = ofs;
+	req.dataoffs = do_div(page, otp_pagesize);
+	req.pos.page = page + layout->start_page;
+	req.type = is_write ? NAND_PAGE_WRITE : NAND_PAGE_READ;
+	req.mode = MTD_OPS_RAW;
+	req.databuf.in = buf;
+
+	while (copied < len) {
+		req.datalen = min_t(unsigned int,
+				    otp_pagesize - req.dataoffs,
+				    len - copied);
+
+		if (is_write)
+			ret = spinand_write_page(spinand, &req);
+		else
+			ret = spinand_read_page(spinand, &req);
+
+		if (ret < 0)
+			break;
+
+		req.databuf.in += req.datalen;
+		req.pos.page++;
+		req.dataoffs = 0;
+		copied += req.datalen;
+	}
+
+	*retlen = copied;
+
+	if (spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0)) {
+		dev_warn(&spinand_to_mtd(spinand)->dev,
+			 "Can not disable OTP mode\n");
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
+/**
+ * spinand_fact_otp_read() - Read from OTP area
+ * @spinand: the spinand device
+ * @ofs: the offset to read
+ * @len: the number of data bytes to read
+ * @retlen: the pointer to variable to store the number of read bytes
+ * @buf: the buffer to store the read data
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+int spinand_fact_otp_read(struct spinand_device *spinand, loff_t ofs,
+			  size_t len, size_t *retlen, u8 *buf)
+{
+	return spinand_otp_rw(spinand, ofs, len, retlen, buf, false,
+			      &spinand->fact_otp->layout);
+}
+
+/**
+ * spinand_user_otp_read() - Read from OTP area
+ * @spinand: the spinand device
+ * @ofs: the offset to read
+ * @len: the number of data bytes to read
+ * @retlen: the pointer to variable to store the number of read bytes
+ * @buf: the buffer to store the read data
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+int spinand_user_otp_read(struct spinand_device *spinand, loff_t ofs,
+			  size_t len, size_t *retlen, u8 *buf)
+{
+	return spinand_otp_rw(spinand, ofs, len, retlen, buf, false,
+			      &spinand->user_otp->layout);
+}
+
+/**
+ * spinand_user_otp_write() - Write to OTP area
+ * @spinand:  the spinand device
+ * @ofs: the offset to write to
+ * @len: the number of bytes to write
+ * @retlen: the pointer to variable to store the number of written bytes
+ * @buf: the buffer with data to write
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+int spinand_user_otp_write(struct spinand_device *spinand, loff_t ofs,
+			   size_t len, size_t *retlen, const u8 *buf)
+{
+	return spinand_otp_rw(spinand, ofs, len, retlen, (u8 *)buf, true,
+			      &spinand->user_otp->layout);
+}
+
+static int spinand_mtd_otp_info(struct mtd_info *mtd, size_t len,
+				size_t *retlen, struct otp_info *buf,
+				bool is_fact)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	int ret;
+
+	*retlen = 0;
+
+	mutex_lock(&spinand->lock);
+
+	if (is_fact)
+		ret = spinand->fact_otp->ops->info(spinand, len, buf, retlen);
+	else
+		ret = spinand->user_otp->ops->info(spinand, len, buf, retlen);
+
+	mutex_unlock(&spinand->lock);
+
+	return ret;
+}
+
+static int spinand_mtd_fact_otp_info(struct mtd_info *mtd, size_t len,
+				     size_t *retlen, struct otp_info *buf)
+{
+	return spinand_mtd_otp_info(mtd, len, retlen, buf, true);
+}
+
+static int spinand_mtd_user_otp_info(struct mtd_info *mtd, size_t len,
+				     size_t *retlen, struct otp_info *buf)
+{
+	return spinand_mtd_otp_info(mtd, len, retlen, buf, false);
+}
+
+static int spinand_mtd_otp_read(struct mtd_info *mtd, loff_t ofs, size_t len,
+				size_t *retlen, u8 *buf, bool is_fact)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	int ret;
+
+	*retlen = 0;
+
+	if (!len)
+		return 0;
+
+	ret = spinand_otp_check_bounds(spinand, ofs, len,
+				       is_fact ? &spinand->fact_otp->layout :
+						 &spinand->user_otp->layout);
+	if (ret)
+		return ret;
+
+	mutex_lock(&spinand->lock);
+
+	if (is_fact)
+		ret = spinand->fact_otp->ops->read(spinand, ofs, len, retlen,
+						   buf);
+	else
+		ret = spinand->user_otp->ops->read(spinand, ofs, len, retlen,
+						   buf);
+
+	mutex_unlock(&spinand->lock);
+
+	return ret;
+}
+
+static int spinand_mtd_fact_otp_read(struct mtd_info *mtd, loff_t ofs,
+				     size_t len, size_t *retlen, u8 *buf)
+{
+	return spinand_mtd_otp_read(mtd, ofs, len, retlen, buf, true);
+}
+
+static int spinand_mtd_user_otp_read(struct mtd_info *mtd, loff_t ofs,
+				     size_t len, size_t *retlen, u8 *buf)
+{
+	return spinand_mtd_otp_read(mtd, ofs, len, retlen, buf, false);
+}
+
+static int spinand_mtd_user_otp_write(struct mtd_info *mtd, loff_t ofs,
+				      size_t len, size_t *retlen, const u8 *buf)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	const struct spinand_user_otp_ops *ops = spinand->user_otp->ops;
+	int ret;
+
+	*retlen = 0;
+
+	if (!len)
+		return 0;
+
+	ret = spinand_user_otp_check_bounds(spinand, ofs, len);
+	if (ret)
+		return ret;
+
+	mutex_lock(&spinand->lock);
+	ret = ops->write(spinand, ofs, len, retlen, buf);
+	mutex_unlock(&spinand->lock);
+
+	return ret;
+}
+
+static int spinand_mtd_user_otp_erase(struct mtd_info *mtd, loff_t ofs,
+				      size_t len)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	const struct spinand_user_otp_ops *ops = spinand->user_otp->ops;
+	int ret;
+
+	if (!len)
+		return 0;
+
+	ret = spinand_user_otp_check_bounds(spinand, ofs, len);
+	if (ret)
+		return ret;
+
+	mutex_lock(&spinand->lock);
+	ret = ops->erase(spinand, ofs, len);
+	mutex_unlock(&spinand->lock);
+
+	return ret;
+}
+
+static int spinand_mtd_user_otp_lock(struct mtd_info *mtd, loff_t ofs,
+				     size_t len)
+{
+	struct spinand_device *spinand = mtd_to_spinand(mtd);
+	const struct spinand_user_otp_ops *ops = spinand->user_otp->ops;
+	int ret;
+
+	if (!len)
+		return 0;
+
+	ret = spinand_user_otp_check_bounds(spinand, ofs, len);
+	if (ret)
+		return ret;
+
+	mutex_lock(&spinand->lock);
+	ret = ops->lock(spinand, ofs, len);
+	mutex_unlock(&spinand->lock);
+
+	return ret;
+}
+
+/**
+ * spinand_set_mtd_otp_ops() - Setup OTP methods
+ * @spinand: the spinand device
+ *
+ * Setup OTP methods.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int spinand_set_mtd_otp_ops(struct spinand_device *spinand)
+{
+	struct mtd_info *mtd = spinand_to_mtd(spinand);
+	const struct spinand_fact_otp_ops *fact_ops = spinand->fact_otp->ops;
+	const struct spinand_user_otp_ops *user_ops = spinand->user_otp->ops;
+
+	if (!user_ops && !fact_ops)
+		return -EINVAL;
+
+	if (user_ops) {
+		if (user_ops->info)
+			mtd->_get_user_prot_info = spinand_mtd_user_otp_info;
+
+		if (user_ops->read)
+			mtd->_read_user_prot_reg = spinand_mtd_user_otp_read;
+
+		if (user_ops->write)
+			mtd->_write_user_prot_reg = spinand_mtd_user_otp_write;
+
+		if (user_ops->lock)
+			mtd->_lock_user_prot_reg = spinand_mtd_user_otp_lock;
+
+		if (user_ops->erase)
+			mtd->_erase_user_prot_reg = spinand_mtd_user_otp_erase;
+	}
+
+	if (fact_ops) {
+		if (fact_ops->info)
+			mtd->_get_fact_prot_info = spinand_mtd_fact_otp_info;
+
+		if (fact_ops->read)
+			mtd->_read_fact_prot_reg = spinand_mtd_fact_otp_read;
+	}
+
+	return 0;
+}