Commit c6ec3e1e authored by Michael Walle's avatar Michael Walle Committed by Vignesh Raghavendra
Browse files

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: default avatarMichael Walle <michael@walle.cc>
Signed-off-by: default avatarVignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: default avatarPratyush Yadav <p.yadav@ti.com>
Reviewed-by: default avatarTudor Ambarus <tudor.ambarus@microchip.com>
parent 388161ca

drivers/mtd/spi-nor/core.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/mtd/spi-nor/core.h

+4 −0
Original line number Diff line number Diff line
@@ -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);

drivers/mtd/spi-nor/otp.c

+86 −0
Original line number Diff line number Diff line
@@ -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;

}

drivers/mtd/spi-nor/winbond.c

+1 −0
Original line number Diff line number Diff line
@@ -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,

};