STRUCT MUX_CONTROL(9)

✨ NAME ✨

struct mux_control is from the Kernel API Manual (section 9, iykyk), and it literally represents a mux controller. That’s the whole main-character job. 💅

💻 SYNOPSIS 💻

okay so here’s the struct in all its glory, character for character because we do not mess with code:

struct mux_control {
    struct semaphore lock;
    struct mux_chip *chip;
    int cached_state;
    unsigned int states;
    int idle_state;
    ktime_t last_change;
 };

🧸 Members 🧸

• lock — protects the mux controller state. 🔒
• chip — the mux chip that is handling this mux controller. 🎛️
• cached_state — the current mux controller state, or -1 if none. 🫧
• states — the number of mux controller states. 🔢
• idle_state — the mux controller state to use when inactive, or one of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT. 😴
• last_change — timestamp of last change. ⏰

🌈 Description 🌈

Real talk, bestie: mux drivers may only change states and idle_state, and they may only do that between allocation and registration of the mux controller. That’s the whole window. 🪟

Specifically, cached_state is internal to the mux core and should never be written by mux drivers — periodt. 🚫

👀 SEE ALSO 👀

Kernel file ./include/linux/mux/driver.h — plus these icons: struct mux_control_ops(9), struct mux_chip(9), mux_chip_priv(9), and mux_control_get_index(9). Go read them if you’re obsessed with mux lore. 📚

k bye bestie 💅 — source/version ./include/linux/mux, October 2026. Mwah 🫶