STRUCT W1_SLAVE(9)

🦋 STRUCT W1_SLAVE(9) — the manual, but make it cute 🦋

okay so bestie, we're in the Kernel API Manual today and we're talking about struct w1_slave(9). it's a lil kernel struct, it's giving "one (1) whole entire slave device on the bus" energy. iconic. let's get into it 💅

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✨ NAME ✨

struct w1_slave — literally just holds a single slave device on the bus. that's her job. that's what she does. 🎀

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🌸 SYNOPSIS 🌸

struct w1_slave {
    struct module           *owner;
    unsigned char           name[W1_MAXNAMELEN];
    struct list_head        w1_slave_entry;
    struct w1_reg_num       reg_num;
    atomic_t refcnt;
    int ttl;
    unsigned long           flags;
    struct w1_master        *master;
    struct w1_family        *family;
    void *family_data;
    struct device           dev;
    struct device           *hwmon;
 };

no cap, that's the whole vibe right there. every field, every one, copied exactly — we do not play about the struct definition 💖

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💅 MEMBERS 💅

okay now the fun part, let's meet the cast 🫶 every single member, none skipped, we're thorough besties:

• owner — points to the one wire "wire" kernel module. she's the owner, she's the main character ✨
• name — the device id, and it's ascii. simple, readable, slay 🌈
• w1_slave_entry — data for the linked list. yes bestie, she's linked 💀
• reg_num — the slave id, but in binary this time. same info, different fit 🔥
• refcnt — reference count, and the rule is delete when it hits 0. goodbye when the count says goodbye 👋
• ttl — decrement per search this slave isn't found, deatch at 0. so if nobody finds her, her time-to-live ticks down each search until she's gone 😭
• flags — bit flags for W1_SLAVE_ACTIVE and W1_SLAVE_DETACH. little status bits doing little status bit things 🎀
• master — the bus which this slave is on. know your bus, respect your bus 🚌
• family — module for the device family type. found family fr fr 💜
• family_data — pointer for use by the family module. it's their data, hands off 🫶
• dev — the kernel device identifier 🦋
• hwmon — pointer to the hwmon device ⭐

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🔍 SEE ALSO 🔍

go read these too, iykyk, they're all in the kernel file ./include/linux/w1.h:

• struct w1_reg_num(9)
• struct w1_bus_master(9)
• enum w1_master_flags(9)
• struct w1_master(9)
• struct w1_family_ops(9)
• struct w1_family(9)
• module_w1_family(9)

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ngl bestie, if you're poking at one-wire stuff in the kernel, read these before you touch anything. future you will be obsessed with past you. 💖

and that's the page!! mwah 💋 this one lives in ./include/linux, from October 2026, and it's struct w1_slave(9) — periodt. 🧚‍♀️✨