[PATCH v2 2/5] mtd: spinand: add OTP support
Martin Kurbanov
mmkurbanov at salutedevices.com
Tue Aug 27 10:49:00 PDT 2024
The MTD subsystem already supports accessing two OTP areas: user and
factory. User areas can be written by the user. This patch only adds
support for the user areas.
In this patch the OTP_INFO macro is provided to add parameters to
spinand_info.
To implement OTP operations, the client (flash driver) is provided with
5 callbacks: .read(), .write(), .info(), .lock(), .erase().
Signed-off-by: Martin Kurbanov <mmkurbanov at salutedevices.com>
---
drivers/mtd/nand/spi/Makefile | 3 +-
drivers/mtd/nand/spi/core.c | 3 +
drivers/mtd/nand/spi/otp.c | 232 ++++++++++++++++++++++++++++++++++
include/linux/mtd/spinand.h | 56 ++++++++
4 files changed, 293 insertions(+), 1 deletion(-)
create mode 100644 drivers/mtd/nand/spi/otp.c
diff --git a/drivers/mtd/nand/spi/Makefile b/drivers/mtd/nand/spi/Makefile
index 19cc77288ebbc..60d2e830ffc6b 100644
--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
-spinand-objs := core.o alliancememory.o ato.o esmt.o foresee.o gigadevice.o macronix.o
+spinand-objs := core.o otp.o
+spinand-objs += alliancememory.o ato.o esmt.o foresee.o gigadevice.o macronix.o
spinand-objs += micron.o paragon.o toshiba.o winbond.o xtx.o
obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 807c24b0c7c4f..2cb825edd49d0 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -1111,6 +1111,7 @@ int spinand_match_and_init(struct spinand_device *spinand,
spinand->flags = table[i].flags;
spinand->id.len = 1 + table[i].devid.len;
spinand->select_target = table[i].select_target;
+ spinand->otp = &table[i].otp;
op = spinand_select_op_variant(spinand,
info->op_variants.read_cache);
@@ -1292,6 +1293,8 @@ static int spinand_init(struct spinand_device *spinand)
mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
mtd->_resume = spinand_mtd_resume;
+ spinand_set_mtd_otp_ops(spinand);
+
if (nand->ecc.engine) {
ret = mtd_ooblayout_count_freebytes(mtd);
if (ret < 0)
diff --git a/drivers/mtd/nand/spi/otp.c b/drivers/mtd/nand/spi/otp.c
new file mode 100644
index 0000000000000..d459f811f9c04
--- /dev/null
+++ b/drivers/mtd/nand/spi/otp.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2024, SaluteDevices. All Rights Reserved.
+ *
+ * Author: Martin Kurbanov <mmkurbanov at salutedevices.com>
+ */
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/spinand.h>
+
+static unsigned int spinand_otp_npages(const struct spinand_device *spinand)
+{
+ return spinand->otp->layout.npages;
+}
+
+static size_t spinand_otp_size(struct spinand_device *spinand)
+{
+ struct nand_device *nand = spinand_to_nand(spinand);
+ size_t otp_pagesize = nanddev_page_size(nand) +
+ nanddev_per_page_oobsize(nand);
+
+ return spinand_otp_npages(spinand) * otp_pagesize;
+}
+
+static int spinand_otp_rw(struct spinand_device *spinand, loff_t ofs,
+ size_t len, u8 *buf, size_t *retlen, bool is_write)
+{
+ struct nand_device *nand = spinand_to_nand(spinand);
+ struct nand_page_io_req req = { 0 };
+ unsigned long long page;
+ size_t copied = 0;
+ size_t otp_pagesize = nanddev_page_size(nand) +
+ nanddev_per_page_oobsize(nand);
+ int ret = 0;
+
+ page = ofs;
+ req.dataoffs = do_div(page, otp_pagesize);
+ req.pos.page = page;
+ req.type = is_write ? NAND_PAGE_WRITE : NAND_PAGE_READ;
+ req.mode = MTD_OPS_RAW;
+ req.databuf.in = buf;
+
+ while (copied < len && req.pos.page < spinand_otp_npages(spinand)) {
+ 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.dataoffs = 0;
+ copied += req.datalen;
+ req.pos.page++;
+ }
+
+ *retlen = copied;
+
+ return ret;
+}
+
+/**
+ * spinand_otp_read() - Read from OTP area
+ * @spinand: the spinand device
+ * @ofs: the offset to read
+ * @len: the number of data bytes to read
+ * @buf: the buffer to store the read data
+ * @retlen: the pointer to variable to store the number of read bytes
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+int spinand_otp_read(struct spinand_device *spinand, loff_t ofs, size_t len,
+ u8 *buf, size_t *retlen)
+{
+ return spinand_otp_rw(spinand, ofs, len, buf, retlen, false);
+}
+
+/**
+ * spinand_otp_write() - Write to OTP area
+ * @spinand: the spinand device
+ * @ofs: the offset to write to
+ * @len: the number of bytes to write
+ * @buf: the buffer with data to write
+ * @retlen: the pointer to variable to store the number of written bytes
+ *
+ * Return: 0 on success, an error code otherwise.
+ */
+int spinand_otp_write(struct spinand_device *spinand, loff_t ofs, size_t len,
+ const u8 *buf, size_t *retlen)
+{
+ return spinand_otp_rw(spinand, ofs, len, (u8 *)buf, retlen, true);
+}
+
+static int spinand_otp_check_bounds(struct spinand_device *spinand, loff_t ofs,
+ size_t len)
+{
+ if (ofs < 0 || ofs + len > spinand_otp_size(spinand))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int spinand_mtd_otp_info(struct mtd_info *mtd, size_t len,
+ size_t *retlen, struct otp_info *buf)
+{
+ struct spinand_device *spinand = mtd_to_spinand(mtd);
+ const struct spinand_otp_ops *ops = spinand->otp->ops;
+ int ret;
+
+ mutex_lock(&spinand->lock);
+ ret = ops->info(spinand, len, buf, retlen);
+ mutex_unlock(&spinand->lock);
+
+ return ret;
+}
+
+static int spinand_mtd_otp_rw(struct mtd_info *mtd, loff_t ofs, size_t len,
+ size_t *retlen, u8 *buf, bool is_write)
+{
+ struct spinand_device *spinand = mtd_to_spinand(mtd);
+ const struct spinand_otp_ops *ops = spinand->otp->ops;
+ int ret;
+
+ if (!len)
+ return 0;
+
+ ret = spinand_otp_check_bounds(spinand, ofs, len);
+ if (ret)
+ return ret;
+
+ mutex_lock(&spinand->lock);
+
+ ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, CFG_OTP_ENABLE);
+ if (ret)
+ goto out_unlock;
+
+ if (is_write)
+ ret = ops->write(spinand, ofs, len, buf, retlen);
+ else
+ ret = ops->read(spinand, ofs, len, buf, retlen);
+
+ if (spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0)) {
+ pr_warn(1, "Can not disable OTP mode\n");
+ ret = -EIO;
+ }
+
+out_unlock:
+ mutex_unlock(&spinand->lock);
+ return ret;
+}
+
+static int spinand_mtd_otp_read(struct mtd_info *mtd, loff_t ofs, size_t len,
+ size_t *retlen, u8 *buf)
+{
+ return spinand_mtd_otp_rw(mtd, ofs, len, retlen, buf, false);
+}
+
+static int spinand_mtd_otp_write(struct mtd_info *mtd, loff_t ofs, size_t len,
+ size_t *retlen, const u8 *buf)
+{
+ return spinand_mtd_otp_rw(mtd, ofs, len, retlen, (u8 *)buf, true);
+}
+
+static int spinand_mtd_otp_erase(struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+ struct spinand_device *spinand = mtd_to_spinand(mtd);
+ const struct spinand_otp_ops *ops = spinand->otp->ops;
+ int ret;
+
+ if (!ops->erase)
+ return -EOPNOTSUPP;
+
+ if (!len)
+ return 0;
+
+ ret = spinand_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_otp_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
+{
+ struct spinand_device *spinand = mtd_to_spinand(mtd);
+ const struct spinand_otp_ops *ops = spinand->otp->ops;
+ int ret;
+
+ if (!ops->lock)
+ return -EOPNOTSUPP;
+
+ if (!len)
+ return 0;
+
+ ret = spinand_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() - Set up OTP methods
+ * @spinand: the spinand device
+ *
+ * Set up OTP methods.
+ */
+void spinand_set_mtd_otp_ops(struct spinand_device *spinand)
+{
+ struct mtd_info *mtd = spinand_to_mtd(spinand);
+
+ if (!spinand->otp->ops)
+ return;
+
+ mtd->_get_user_prot_info = spinand_mtd_otp_info;
+ mtd->_read_user_prot_reg = spinand_mtd_otp_read;
+ mtd->_write_user_prot_reg = spinand_mtd_otp_write;
+ mtd->_lock_user_prot_reg = spinand_mtd_otp_lock;
+ mtd->_erase_user_prot_reg = spinand_mtd_otp_erase;
+}
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 555846517faf6..8099f35f0e051 100644
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -322,6 +322,43 @@ struct spinand_ondie_ecc_conf {
u8 status;
};
+/**
+ * struct spinand_otp_layout - structure to describe the SPI NAND OTP area
+ * @npages: number of pages in the OTP
+ */
+struct spinand_otp_layout {
+ unsigned int npages;
+};
+
+/**
+ * struct spinand_otp_ops - SPI NAND OTP methods
+ * @info: Get the OTP area information
+ * @lock: lock an OTP region
+ * @erase: erase an OTP region
+ * @read: read from the SPI NAND OTP area
+ * @write: write to the SPI NAND OTP area
+ */
+struct spinand_otp_ops {
+ int (*info)(struct spinand_device *spinand, size_t len,
+ struct otp_info *buf, size_t *retlen);
+ int (*lock)(struct spinand_device *spinand, loff_t from, size_t len);
+ int (*erase)(struct spinand_device *spinand, loff_t from, size_t len);
+ int (*read)(struct spinand_device *spinand, loff_t from, size_t len,
+ u8 *buf, size_t *retlen);
+ int (*write)(struct spinand_device *spinand, loff_t from, size_t len,
+ const u8 *buf, size_t *retlen);
+};
+
+/**
+ * struct spinand_otp - SPI NAND OTP grouping structure
+ * @layout: OTP region layout
+ * @ops: OTP access ops
+ */
+struct spinand_otp {
+ const struct spinand_otp_layout layout;
+ const struct spinand_otp_ops *ops;
+};
+
/**
* struct spinand_info - Structure used to describe SPI NAND chips
* @model: model name
@@ -354,6 +391,7 @@ struct spinand_info {
} op_variants;
int (*select_target)(struct spinand_device *spinand,
unsigned int target);
+ struct spinand_otp otp;
};
#define SPINAND_ID(__method, ...) \
@@ -379,6 +417,14 @@ struct spinand_info {
#define SPINAND_SELECT_TARGET(__func) \
.select_target = __func,
+#define SPINAND_OTP_INFO(__npages, __ops) \
+ .otp = { \
+ .layout = { \
+ .npages = __npages, \
+ }, \
+ .ops = __ops, \
+ }
+
#define SPINAND_INFO(__model, __id, __memorg, __eccreq, __op_variants, \
__flags, ...) \
{ \
@@ -422,6 +468,7 @@ struct spinand_dirmap {
* passed in spi_mem_op be DMA-able, so we can't based the bufs on
* the stack
* @manufacturer: SPI NAND manufacturer information
+ * @otp: SPI NAND OTP info.
* @priv: manufacturer private data
*/
struct spinand_device {
@@ -450,6 +497,7 @@ struct spinand_device {
u8 *oobbuf;
u8 *scratchbuf;
const struct spinand_manufacturer *manufacturer;
+ const struct spinand_otp *otp;
void *priv;
};
@@ -525,4 +573,12 @@ int spinand_read_page(struct spinand_device *spinand,
int spinand_write_page(struct spinand_device *spinand,
const struct nand_page_io_req *req);
+void spinand_set_mtd_otp_ops(struct spinand_device *spinand);
+
+int spinand_otp_read(struct spinand_device *spinand, loff_t ofs, size_t len,
+ u8 *buf, size_t *retlen);
+
+int spinand_otp_write(struct spinand_device *spinand, loff_t ofs, size_t len,
+ const u8 *buf, size_t *retlen);
+
#endif /* __LINUX_MTD_SPINAND_H */
--
2.43.2
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