From e3c1f1c92d6ede3cfa09d6a103d3d1c1ef645e35 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Wed, 3 Mar 2021 21:18:19 +0100 Subject: [PATCH] mtd: add OTP (one-time-programmable) erase ioctl This may sound like a contradiction but some SPI-NOR flashes really support erasing their OTP region until it is finally locked. Having the possibility to erase an OTP region might come in handy during development. The ioctl argument follows the OTPLOCK style. Signed-off-by: Michael Walle Acked-by: Vignesh Raghavendra Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210303201819.2752-1-michael@walle.cc --- drivers/mtd/mtdchar.c | 7 ++++++- drivers/mtd/mtdcore.c | 12 ++++++++++++ include/linux/mtd/mtd.h | 3 +++ include/uapi/mtd/mtd-abi.h | 2 ++ 4 files changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 870f7a19ad9d..155e991d9d75 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -666,6 +666,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) case MEMWRITEOOB64: case MEMWRITE: case OTPLOCK: + case OTPERASE: if (!(file->f_mode & FMODE_WRITE)) return -EPERM; break; @@ -930,6 +931,7 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) } case OTPLOCK: + case OTPERASE: { struct otp_info oinfo; @@ -937,7 +939,10 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) return -EINVAL; if (copy_from_user(&oinfo, argp, sizeof(oinfo))) return -EFAULT; - ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length); + if (cmd == OTPLOCK) + ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length); + else + ret = mtd_erase_user_prot_reg(mtd, oinfo.start, oinfo.length); break; } diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 38782ceea1f6..aea58366a94e 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -1919,6 +1919,18 @@ int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) } EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg); +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len) +{ + struct mtd_info *master = mtd_get_master(mtd); + + if (!master->_erase_user_prot_reg) + return -EOPNOTSUPP; + if (!len) + return 0; + return master->_erase_user_prot_reg(master, from, len); +} +EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg); + /* Chip-supported device locking */ int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len) { diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index ceabc2cae8a4..4aac200ca8b5 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -337,6 +337,8 @@ struct mtd_info { size_t len, size_t *retlen, u_char *buf); int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from, size_t len); + int (*_erase_user_prot_reg) (struct mtd_info *mtd, loff_t from, + size_t len); int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen); void (*_sync) (struct mtd_info *mtd); @@ -518,6 +520,7 @@ int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len, int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, u_char *buf); int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len); +int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len); int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, unsigned long count, loff_t to, size_t *retlen); diff --git a/include/uapi/mtd/mtd-abi.h b/include/uapi/mtd/mtd-abi.h index 65b9db936557..b869990c2db2 100644 --- a/include/uapi/mtd/mtd-abi.h +++ b/include/uapi/mtd/mtd-abi.h @@ -205,6 +205,8 @@ struct otp_info { * without OOB, e.g., NOR flash. */ #define MEMWRITE _IOWR('M', 24, struct mtd_write_req) +/* Erase a given range of user data (must be in mode %MTD_FILE_MODE_OTP_USER) */ +#define OTPERASE _IOW('M', 25, struct otp_info) /* * Obsolete legacy interface. Keep it in order not to break userspace