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Message-Id: <20210604100252.9975-6-michael@walle.cc>
Date: Fri, 4 Jun 2021 12:02:52 +0200
From: Michael Walle <michael@...le.cc>
To: linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: Tudor Ambarus <tudor.ambarus@...rochip.com>,
Michael Walle <michael@...le.cc>,
Pratyush Yadav <p.yadav@...com>,
Miquel Raynal <miquel.raynal@...tlin.com>,
Richard Weinberger <richard@....at>,
Vignesh Raghavendra <vigneshr@...com>
Subject: [PATCH v5 5/5] mtd: spi-nor: otp: implement erase for Winbond and similar flashes
Winbond flashes with OTP support provide a command to erase the OTP
data. This might come in handy during development.
This was tested with a Winbond W25Q32JW on a LS1028A SoC with the
NXP FSPI controller.
Signed-off-by: Michael Walle <michael@...le.cc>
Reviewed-by: Pratyush Yadav <p.yadav@...com>
---
drivers/mtd/spi-nor/core.c | 2 +-
drivers/mtd/spi-nor/core.h | 4 ++
drivers/mtd/spi-nor/otp.c | 86 +++++++++++++++++++++++++++++++++++
drivers/mtd/spi-nor/winbond.c | 1 +
4 files changed, 92 insertions(+), 1 deletion(-)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index f6a6ef2d8bd8..a21b0085de05 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -1318,7 +1318,7 @@ static u32 spi_nor_convert_addr(struct spi_nor *nor, loff_t addr)
/*
* Initiate the erasure of a single sector
*/
-static int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
+int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
{
int i;
diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 28a2e0be97a3..9398a8738857 100644
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -207,6 +207,7 @@ struct spi_nor_otp_organization {
* @read: read from the SPI NOR OTP area.
* @write: write to the SPI NOR OTP area.
* @lock: lock an OTP region.
+ * @erase: erase an OTP region.
* @is_locked: check if an OTP region of the SPI NOR is locked.
*/
struct spi_nor_otp_ops {
@@ -214,6 +215,7 @@ struct spi_nor_otp_ops {
int (*write)(struct spi_nor *nor, loff_t addr, size_t len,
const u8 *buf);
int (*lock)(struct spi_nor *nor, unsigned int region);
+ int (*erase)(struct spi_nor *nor, loff_t addr);
int (*is_locked)(struct spi_nor *nor, unsigned int region);
};
@@ -503,10 +505,12 @@ ssize_t spi_nor_read_data(struct spi_nor *nor, loff_t from, size_t len,
u8 *buf);
ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
const u8 *buf);
+int spi_nor_erase_sector(struct spi_nor *nor, u32 addr);
int spi_nor_otp_read_secr(struct spi_nor *nor, loff_t addr, size_t len, u8 *buf);
int spi_nor_otp_write_secr(struct spi_nor *nor, loff_t addr, size_t len,
const u8 *buf);
+int spi_nor_otp_erase_secr(struct spi_nor *nor, loff_t addr);
int spi_nor_otp_lock_sr2(struct spi_nor *nor, unsigned int region);
int spi_nor_otp_is_locked_sr2(struct spi_nor *nor, unsigned int region);
diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c
index 89fe52e3851a..983e40b19134 100644
--- a/drivers/mtd/spi-nor/otp.c
+++ b/drivers/mtd/spi-nor/otp.c
@@ -120,6 +120,38 @@ int spi_nor_otp_write_secr(struct spi_nor *nor, loff_t addr, size_t len,
return ret ?: written;
}
+/**
+ * spi_nor_otp_erase_secr() - erase a security register
+ * @nor: pointer to 'struct spi_nor'
+ * @addr: offset of the security register to be erased
+ *
+ * Erase a security register by using the SPINOR_OP_ESECR command.
+ *
+ * For more information on the term "security register", see the documentation
+ * of spi_nor_otp_read_secr().
+ *
+ * This method is used on GigaDevice and Winbond flashes.
+ *
+ * Return: 0 on success, -errno otherwise
+ */
+int spi_nor_otp_erase_secr(struct spi_nor *nor, loff_t addr)
+{
+ u8 erase_opcode = nor->erase_opcode;
+ int ret;
+
+ ret = spi_nor_write_enable(nor);
+ if (ret)
+ return ret;
+
+ nor->erase_opcode = SPINOR_OP_ESECR;
+ ret = spi_nor_erase_sector(nor, addr);
+ nor->erase_opcode = erase_opcode;
+ if (ret)
+ return ret;
+
+ return spi_nor_wait_till_ready(nor);
+}
+
static int spi_nor_otp_lock_bit_cr(unsigned int region)
{
static const int lock_bits[] = { SR2_LB1, SR2_LB2, SR2_LB3 };
@@ -360,6 +392,59 @@ static int spi_nor_mtd_otp_write(struct mtd_info *mtd, loff_t to, size_t len,
return spi_nor_mtd_otp_read_write(mtd, to, len, retlen, buf, true);
}
+static int spi_nor_mtd_otp_erase(struct mtd_info *mtd, loff_t from, size_t len)
+{
+ struct spi_nor *nor = mtd_to_spi_nor(mtd);
+ const struct spi_nor_otp_ops *ops = nor->params->otp.ops;
+ const size_t rlen = spi_nor_otp_region_len(nor);
+ unsigned int region;
+ loff_t rstart;
+ int ret;
+
+ /* OTP erase is optional */
+ if (!ops->erase)
+ return -EOPNOTSUPP;
+
+ if (!len)
+ return 0;
+
+ if (from < 0 || (from + len) > spi_nor_otp_size(nor))
+ return -EINVAL;
+
+ /* the user has to explicitly ask for whole regions */
+ if (!IS_ALIGNED(len, rlen) || !IS_ALIGNED(from, rlen))
+ return -EINVAL;
+
+ ret = spi_nor_lock_and_prep(nor);
+ if (ret)
+ return ret;
+
+ ret = spi_nor_mtd_otp_range_is_locked(nor, from, len);
+ if (ret < 0) {
+ goto out;
+ } else if (ret) {
+ ret = -EROFS;
+ goto out;
+ }
+
+ while (len) {
+ region = spi_nor_otp_offset_to_region(nor, from);
+ rstart = spi_nor_otp_region_start(nor, region);
+
+ ret = ops->erase(nor, rstart);
+ if (ret)
+ goto out;
+
+ len -= rlen;
+ from += rlen;
+ }
+
+out:
+ spi_nor_unlock_and_unprep(nor);
+
+ return ret;
+}
+
static int spi_nor_mtd_otp_lock(struct mtd_info *mtd, loff_t from, size_t len)
{
struct spi_nor *nor = mtd_to_spi_nor(mtd);
@@ -418,4 +503,5 @@ void spi_nor_otp_init(struct spi_nor *nor)
mtd->_read_user_prot_reg = spi_nor_mtd_otp_read;
mtd->_write_user_prot_reg = spi_nor_mtd_otp_write;
mtd->_lock_user_prot_reg = spi_nor_mtd_otp_lock;
+ mtd->_erase_user_prot_reg = spi_nor_mtd_otp_erase;
}
diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index 9a81c67a60c6..96573f61caf5 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -139,6 +139,7 @@ static int winbond_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
static const struct spi_nor_otp_ops winbond_otp_ops = {
.read = spi_nor_otp_read_secr,
.write = spi_nor_otp_write_secr,
+ .erase = spi_nor_otp_erase_secr,
.lock = spi_nor_otp_lock_sr2,
.is_locked = spi_nor_otp_is_locked_sr2,
};
--
2.20.1
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