STRUCT SPI_NOR(9)

okay so bestie, this is struct spi_nor(9) from the Kernel API Manual — yes, the big one — and it's lowkey iconic. 💅

💖 NAME 💖

struct spi_nor — the structure for defining the SPI NOR layer. that's the whole assignment, and it ate, periodt. ✨

✨ SYNOPSIS ✨

here's the entire struct, no cap — every field exactly as it appears:

       struct spi_nor {
           struct mtd_info         mtd;
           struct mutex            lock;
           struct spi_nor_rww {
             wait_queue_head_t wait;
             bool ongoing_io;
             bool ongoing_rd;
             bool ongoing_pe;
             unsigned int    used_banks;
           } rww;
           struct device           *dev;
           struct spi_mem          *spimem;
           u8 *bouncebuf;
           size_t bouncebuf_size;
           u8 *id;
           const struct flash_info *info;
           const struct spi_nor_manufacturer *manufacturer;
           u8 addr_nbytes;
           u8 erase_opcode;
           u8 read_opcode;
           u8 read_dummy;
           u8 program_opcode;
           enum spi_nor_protocol   read_proto;
           enum spi_nor_protocol   write_proto;
           enum spi_nor_protocol   reg_proto;
           bool sst_write_second;
           u32 flags;
           enum spi_nor_cmd_ext    cmd_ext_type;
           struct sfdp             *sfdp;
           struct dentry           *debugfs_root;
           u8 dfs_sr_cache[2];
           const struct spi_nor_controller_ops *controller_ops;
           struct spi_nor_flash_parameter *params;
           struct {
             struct spi_mem_dirmap_desc *rdesc;
             struct spi_mem_dirmap_desc *wdesc;
           } dirmap;
           void *priv;
        };

🧸 Members 🧸

vibe check on every single member — no skips, no crumbs left behind:

• mtd — an mtd_info structure
• lock — the lock for the read/write/erase/lock/unlock operations
• rww — Read-While-Write (RWW) sync lock
  • rww.wait — wait queue for the RWW sync
  • rww.ongoing_io — the bus is busy
  • rww.ongoing_rd — a read is ongoing on the chip
  • rww.ongoing_pe — a program/erase is ongoing on the chip
  • rww.used_banks — bitmap of the banks in use
• dev — pointer to an SPI device or an SPI NOR controller device
• spimem — pointer to the SPI memory device
• bouncebuf — bounce buffer used when the buffer passed by the MTD layer is not DMA-able
• bouncebuf_size — size of the bounce buffer
• id — The flash's ID bytes. Always contains SPI_NOR_MAX_ID_LEN bytes.
• info — SPI NOR part JEDEC MFR ID and other info
• manufacturer — SPI NOR manufacturer
• addr_nbytes — number of address bytes
• erase_opcode — the opcode for erasing a sector
• read_opcode — the read opcode
• read_dummy — the dummy needed by the read operation
• program_opcode — the program opcode
• read_proto — the SPI protocol for read operations
• write_proto — the SPI protocol for write operations
• reg_proto — the SPI protocol for read_reg/write_reg/erase operations
• sst_write_second — used by the SST write operation
• flags — flag options for the current SPI NOR (SNOR_F_*)
• cmd_ext_type — the command opcode extension type for DTR mode.
• sfdp — the SFDP data of the flash
• debugfs_root — pointer to the debugfs directory
• dfs_sr_cache — Status Register cached value for debugfs use only
• controller_ops — SPI NOR controller driver specific operations.
• params — [FLASH-SPECIFIC] SPI NOR flash parameters and settings. The structure includes legacy flash parameters and settings that can be overwritten by the spi_nor_fixups hooks, or dynamically when parsing the SFDP tables.
• dirmap — pointers to struct spi_mem_dirmap_desc for reads/writes.
• priv — pointer to the private data

🌈 SEE ALSO 🌈

go peek at the Kernel file ./include/linux/mtd/spi-nor.h, plus these besties: struct spi_nor_hwcaps(9), struct spi_nor_controller_ops(9), enum spi_nor_cmd_ext(9), and spi_nor_scan(9). iykyk 💅

that's the whole page, bestie 🫶. footer energy: source/version ./include/linux/mtd, date October 2026, title struct spi_nor(9) — mwah 💋