diff options
| -rw-r--r-- | include/linux/mtd/mtd.h | 2 | ||||
| -rw-r--r-- | include/mtd/mtd-abi.h | 86 |
2 files changed, 74 insertions, 14 deletions
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index c2047b85691d..37d082793f62 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -79,7 +79,7 @@ struct mtd_erase_region_info { * @ooblen: number of oob bytes to write/read * @oobretlen: number of oob bytes written/read * @ooboffs: offset of oob data in the oob area (only relevant when - * mode = MTD_OPS_PLACE_OOB) + * mode = MTD_OPS_PLACE_OOB or MTD_OPS_RAW) * @datbuf: data buffer - if NULL only oob data are read/written * @oobbuf: oob data buffer * diff --git a/include/mtd/mtd-abi.h b/include/mtd/mtd-abi.h index 1a16046b1d97..7dee9709fbfc 100644 --- a/include/mtd/mtd-abi.h +++ b/include/mtd/mtd-abi.h @@ -45,14 +45,18 @@ struct mtd_oob_buf64 { __u64 usr_ptr; }; -/* +/** * MTD operation modes * - * MTD_OPS_PLACE_OOB: oob data are placed at the given offset (default) - * MTD_OPS_AUTO_OOB: oob data are automatically placed at the free areas + * @MTD_OPS_PLACE_OOB: OOB data are placed at the given offset (default) + * @MTD_OPS_AUTO_OOB: OOB data are automatically placed at the free areas * which are defined by the internal ecclayout - * MTD_OPS_RAW: mode to read or write oob and data without doing ECC - * checking + * @MTD_OPS_RAW: data are transferred as-is, with no error correction; + * this mode implies %MTD_OPS_PLACE_OOB + * + * These modes can be passed to ioctl(MEMWRITE) and are also used internally. + * See notes on "MTD file modes" for discussion on %MTD_OPS_RAW vs. + * %MTD_FILE_MODE_RAW. */ enum { MTD_OPS_PLACE_OOB = 0, @@ -60,6 +64,22 @@ enum { MTD_OPS_RAW = 2, }; +/** + * struct mtd_write_req - data structure for requesting a write operation + * + * @start: start address + * @len: length of data buffer + * @ooblen: length of OOB buffer + * @usr_data: user-provided data buffer + * @usr_oob: user-provided OOB buffer + * @mode: MTD mode (see "MTD operation modes") + * @padding: reserved, must be set to 0 + * + * This structure supports ioctl(MEMWRITE) operations, allowing data and/or OOB + * writes in various modes. To write to OOB-only, set @usr_data == NULL, and to + * write data-only, set @usr_oob == NULL. However, setting both @usr_data and + * @usr_oob to NULL is not allowed. + */ struct mtd_write_req { __u64 start; __u64 len; @@ -84,13 +104,13 @@ struct mtd_write_req { #define MTD_NO_ERASE 0x1000 /* No erase necessary */ #define MTD_POWERUP_LOCK 0x2000 /* Always locked after reset */ -// Some common devices / combinations of capabilities +/* Some common devices / combinations of capabilities */ #define MTD_CAP_ROM 0 #define MTD_CAP_RAM (MTD_WRITEABLE | MTD_BIT_WRITEABLE | MTD_NO_ERASE) #define MTD_CAP_NORFLASH (MTD_WRITEABLE | MTD_BIT_WRITEABLE) #define MTD_CAP_NANDFLASH (MTD_WRITEABLE) -/* ECC byte placement */ +/* Obsolete ECC byte placement modes (used with obsolete MEMGETOOBSEL) */ #define MTD_NANDECC_OFF 0 // Switch off ECC (Not recommended) #define MTD_NANDECC_PLACE 1 // Use the given placement in the structure (YAFFS1 legacy mode) #define MTD_NANDECC_AUTOPLACE 2 // Use the default placement scheme @@ -105,10 +125,10 @@ struct mtd_write_req { struct mtd_info_user { __u8 type; __u32 flags; - __u32 size; // Total size of the MTD + __u32 size; /* Total size of the MTD */ __u32 erasesize; __u32 writesize; - __u32 oobsize; // Amount of OOB data per block (e.g. 16) + __u32 oobsize; /* Amount of OOB data per block (e.g. 16) */ /* The below two fields are obsolete and broken, do not use them * (TODO: remove at some point) */ __u32 ecctype; @@ -117,9 +137,9 @@ struct mtd_info_user { struct region_info_user { __u32 offset; /* At which this region starts, - * from the beginning of the MTD */ - __u32 erasesize; /* For this region */ - __u32 numblocks; /* Number of blocks in this region */ + * from the beginning of the MTD */ + __u32 erasesize; /* For this region */ + __u32 numblocks; /* Number of blocks in this region */ __u32 regionindex; }; @@ -135,28 +155,54 @@ struct otp_info { * Try to avoid adding a new ioctl with the same ioctl number. */ +/* Get basic MTD characteristics info (better to use sysfs) */ #define MEMGETINFO _IOR('M', 1, struct mtd_info_user) +/* Erase segment of MTD */ #define MEMERASE _IOW('M', 2, struct erase_info_user) +/* Write out-of-band data from MTD */ #define MEMWRITEOOB _IOWR('M', 3, struct mtd_oob_buf) +/* Read out-of-band data from MTD */ #define MEMREADOOB _IOWR('M', 4, struct mtd_oob_buf) +/* Lock a chip (for MTD that supports it) */ #define MEMLOCK _IOW('M', 5, struct erase_info_user) +/* Unlock a chip (for MTD that supports it) */ #define MEMUNLOCK _IOW('M', 6, struct erase_info_user) +/* Get the number of different erase regions */ #define MEMGETREGIONCOUNT _IOR('M', 7, int) +/* Get information about the erase region for a specific index */ #define MEMGETREGIONINFO _IOWR('M', 8, struct region_info_user) +/* Get info about OOB modes (e.g., RAW, PLACE, AUTO) - legacy interface */ #define MEMGETOOBSEL _IOR('M', 10, struct nand_oobinfo) +/* Check if an eraseblock is bad */ #define MEMGETBADBLOCK _IOW('M', 11, __kernel_loff_t) +/* Mark an eraseblock as bad */ #define MEMSETBADBLOCK _IOW('M', 12, __kernel_loff_t) +/* Set OTP (One-Time Programmable) mode (factory vs. user) */ #define OTPSELECT _IOR('M', 13, int) +/* Get number of OTP (One-Time Programmable) regions */ #define OTPGETREGIONCOUNT _IOW('M', 14, int) +/* Get all OTP (One-Time Programmable) info about MTD */ #define OTPGETREGIONINFO _IOW('M', 15, struct otp_info) +/* Lock a given range of user data (must be in mode %MTD_FILE_MODE_OTP_USER) */ #define OTPLOCK _IOR('M', 16, struct otp_info) +/* Get ECC layout (deprecated) */ #define ECCGETLAYOUT _IOR('M', 17, struct nand_ecclayout_user) +/* Get statistics about corrected/uncorrected errors */ #define ECCGETSTATS _IOR('M', 18, struct mtd_ecc_stats) +/* Set MTD mode on a per-file-descriptor basis (see "MTD file modes") */ #define MTDFILEMODE _IO('M', 19) +/* Erase segment of MTD (supports 64-bit address) */ #define MEMERASE64 _IOW('M', 20, struct erase_info_user64) +/* Write data to OOB (64-bit version) */ #define MEMWRITEOOB64 _IOWR('M', 21, struct mtd_oob_buf64) +/* Read data from OOB (64-bit version) */ #define MEMREADOOB64 _IOWR('M', 22, struct mtd_oob_buf64) +/* Check if chip is locked (for MTD that supports it) */ #define MEMISLOCKED _IOR('M', 23, struct erase_info_user) +/* + * Most generic write interface; can write in-band and/or out-of-band in various + * modes (see "struct mtd_write_req") + */ #define MEMWRITE _IOWR('M', 24, struct mtd_write_req) /* @@ -208,7 +254,21 @@ struct mtd_ecc_stats { }; /* - * Read/write file modes for access to MTD + * MTD file modes - for read/write access to MTD + * + * @MTD_FILE_MODE_NORMAL: OTP disabled, ECC enabled + * @MTD_FILE_MODE_OTP_FACTORY: OTP enabled in factory mode + * @MTD_FILE_MODE_OTP_USER: OTP enabled in user mode + * @MTD_FILE_MODE_RAW: OTP disabled, ECC disabled + * + * These modes can be set via ioctl(MTDFILEMODE). The mode mode will be retained + * separately for each open file descriptor. + * + * Note: %MTD_FILE_MODE_RAW provides the same functionality as %MTD_OPS_RAW - + * raw access to the flash, without error correction or autoplacement schemes. + * Wherever possible, the MTD_OPS_* mode will override the MTD_FILE_MODE_* mode + * (e.g., when using ioctl(MEMWRITE)), but in some cases, the MTD_FILE_MODE is + * used out of necessity (e.g., `write()', ioctl(MEMWRITEOOB64)). */ enum mtd_file_modes { MTD_FILE_MODE_NORMAL = MTD_OTP_OFF, |