STRUCT ISSEI_DEVICE(9)

🎀 struct issei_device(9) 🎀

okay bestie, welcome to the Kernel API Manual ✨ this page is all about struct issei_device and it's genuinely a lot, so grab a snack 🍓

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💖 NAME 💖

struct issei_device — the issei device, like, the whole vibe of one 🦋

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✨ SYNOPSIS ✨

struct issei_device {
    struct device *parent;
    struct device dev;
    struct cdev *cdev;
    u32 minor;
    wait_queue_head_t wait_has_data;
    bool has_data;
    bool power_down;
    wait_queue_head_t wait_rst_state;
    enum issei_rst_state rst_state;
    u16 fw_protocol_ver;
    u16 fw_version[4];
    struct task_struct *process_thread;
    u8 reset_count;
    u8 all_reset_count;
    struct mutex client_lock;
    struct list_head host_client_list;
    u16 host_client_last_id;
    u8 host_client_count;
    struct kset *fw_clients;
    struct list_head fw_client_list;
    struct list_head write_queue;
    ktime_t last_write_ts;
    struct issei_dma dma;
    const struct issei_hw_ops *ops;
    char hw[];
};

no cap, that's the entire struct, copied character for character 💅

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🌸 Members 🌸

okay so now we go member by member, main-character style 👑

• parent — the parent device object, aka who brought you into this world 🫶
• dev — the associated device object that goes with it
• cdev — the character device, the classic /dev situation
• minor — the allocated minor number, the numbers are real 🔢
• wait_has_data — a wait queue for data, so people can chill until there's something to do
• has_data — literally just "there are data to process" — iconic, no notes
• power_down — the device is powering down, wrap it up 💀
• wait_rst_state — the waitqueue for reset state processing, so you wait pretty for the reset
• rst_state — the reset state itself
• fw_protocol_ver — the protocol version, iykyk
• fw_version — the firmware version
• process_thread — the worker thread doing the actual labor 😭
• reset_count — number of consecutive link reset attempts (consecutive!! important!!)
• all_reset_count — the cumulative number of link reset attempts, the big-picture total
• client_lock — a mutex to protect the client lists and the write queue 🔒 do not skip this one bestie
• host_client_list — the host clients list
• host_client_last_id — the last allocated host client id
• host_client_count — number of active host clients
• fw_client_list — the firmware clients list
• write_queue — the write queue, exactly what it says 🎀
• last_write_ts — the last write timestamp, so you always know when the last write happened ⏰
• dma — the DMA memory configuration
• ops — the hardware operations
• hw — hw-specific data, the flexible little tail of the struct 🧚

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🦋 SEE ALSO 🦋

• Kernel file ./drivers/misc/issei/issei_dev.h — start there, fr fr
• struct issei_write_buf(9)
• struct issei_hw_ops(9)
• enum issei_rst_state(9)

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and that's the whole page, periodt 💜 this little beauty lives in ./drivers/misc/issei and the version is dated October 2026 — go off, issei device, we're obsessed 🌈⭐

struct issei_device(9) 🎀