STRUCT ALPS_DATA(9)

💖 NAME 💖

struct alps_data — the private data structure for the ALPS driver, aka the driver's own little diary that nobody else gets to read 📔✨

(hi bestie, welcome to struct alps_data(9), straight out of the Kernel API Manual — yes we're in the kernel docs and yes we're gonna have a good time 🫶)

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✨ SYNOPSIS ✨

okay so the whole thing looks like this, and I need you to look at it with your whole chest because it's lowkey a lot:

struct alps_data {
    struct psmouse *psmouse;
    struct input_dev *dev2;
    struct input_dev *dev3;
    char phys2[32];
    char phys3[32];
    struct work_struct dev3_register_work;
    const struct alps_nibble_commands *nibble_commands;
    int addr_command;
    u16 proto_version;
    u8 byte0, mask0;
    u8 dev_id[3];
    u8 fw_ver[3];
    int flags;
    int x_max;
    int y_max;
    int x_bits;
    int y_bits;
    unsigned int x_res;
    unsigned int y_res;
    int (*hw_init)(struct psmouse *psmouse);
    void (*process_packet)(struct psmouse *psmouse);
    int (*decode_fields)(struct alps_fields *f, unsigned char *p, struct psmouse *psmouse);
    void (*set_abs_params)(struct alps_data *priv, struct input_dev *dev1);
    int prev_fin;
    int multi_packet;
    int second_touch;
    unsigned char multi_data[6];
    struct alps_fields f;
    u8 quirks;
    struct timer_list timer;
 };

no cap, that's the whole vibe. now let's go field by field 💅

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🎀 MEMBERS 🎀

okay so EVERY member, in order, no skipping, because we do not leave lore on the table:

• psmouse — pointer to the parent psmouse device. it's giving "my mom is the psmouse device" energy 👑
• dev2 — the trackstick device. and guess what, it can be NULL 🙈
• dev3 — a generic PS/2 mouse. also can be NULL, and its registering is delayed — it's running late, like me to literally everything ⏰
• phys2 — the physical path for the trackstick device 🛤️
• phys3 — the physical path for the generic PS/2 mouse 🛤️
• dev3_register_work — a work instance used for registering the PS/2 mouse. it's the little task that gets the generic mouse through the door 🚪
• nibble_commands — the command mapping used for touchpad register accesses. nibble. nibble. 🍓 iykyk
• addr_command — the command used to tell the touchpad that a register address is coming next. it's literally "hey babe, an address follows" 📬
• proto_version — tells you if this is V1/V2/V3/... 🔢 (yes the "..." is doing a lot of heavy lifting, don't come for it)
• byte0 — helps figure out whether a position report packet matches the known format for this model. the first byte of the report, ANDed with mask0, should match byte0. ok so byte0 & mask0 == byte0-core, if you will ✨
• mask0 — the mask used to check the first byte of the report 🎭
• fw_ver — a cached copy of the firmware version (EC report). it's not live, it's a screenshot 📸
• flags — additional device capabilities (passthrough port, trackstick, etc.) 🚩
• x_max — largest possible X position value 📏
• y_max — largest possible Y position value 📏
• x_bits — number of X bits in the MT bitmap 🧮
• y_bits — number of Y bits in the MT bitmap 🧮
• hw_init — protocol-specific hardware init function. main character energy for the setup arc 🌱
• process_packet — protocol-specific function to process a report packet 📦
• decode_fields — protocol-specific function to read packet bitfields 🔍
• set_abs_params — protocol-specific function to configure the input_dev ⚙️
• prev_fin — the finger bit from the previous packet 👆 (fin = finger, not fish, bestie)
• multi_packet — multi-packet data currently in progress 🚧
• multi_data — saved multi-packet data 💾
• f — decoded packet data fields, living in a struct alps_fields 🗂️
• quirks — bitmap of ALPS_QUIRK_* 💅 (quirks are the personality traits of hardware)
• timer — timer for flushing out the final report packet in the stream 🚽✨ (flush. get it. it's a timer.)

bestie real talk: the struct also has dev_id, x_res, y_res, and second_touch up in the synopsis, but this page doesn't describe them. I am NOT inventing lore. we simply do not know them like that 🤷‍♀️

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🦋 SEE ALSO 🦋

go read these next, they're literally in the kernel file ./drivers/input/mouse/alps.h:

• struct alps_protocol_info(9)
• struct alps_model_info(9)
• struct alps_nibble_commands(9)
• struct alps_fields(9)

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🌸 and that's the page!! this whole thing lives in ./drivers/input/mouse, it's dated October 2026, and it's filed under struct alps_data(9) — go off, kernel docs, you ate 💅💖✨🎀