STRUCT CLOCK_EVENT_DEVICE(9)

💖 NAME 💖

okay so you opened the struct clock_event_device(9) page in the Kernel API Manual, and the NAME section is literally clock event device descriptor — that’s the whole vibe, bestie 💅. This struct is the descriptor for a clock event device, and we’re about to go through every field like it’s a group-chat roll call 👑

✨ SYNOPSIS ✨

here’s the struct, copied exactly so there’s zero ambiguity, no cap:

       struct clock_event_device {
           void (*event_handler)(struct clock_event_device *);
           int (*set_next_event)(unsigned long evt, struct clock_event_device
       *);
           int (*set_next_ktime)(ktime_t expires, struct clock_event_device *);
           void (*set_next_coupled)(u64 cycles, struct clock_event_device *);
           ktime_t next_event;
           u64 max_delta_ns;
           u64 min_delta_ns;
           u32 mult;
           u32 shift;
           enum clock_event_state  state_use_accessors;
           unsigned int            features;
           enum clocksource_ids    cs_id;
           unsigned int            next_event_forced;
           unsigned long           retries;
           int (*set_state_periodic)(struct clock_event_device *);
           int (*set_state_oneshot)(struct clock_event_device *);
           int (*set_state_oneshot_stopped)(struct clock_event_device *);
           int (*set_state_shutdown)(struct clock_event_device *);
           int (*tick_resume)(struct clock_event_device *);
           void (*broadcast)(const struct cpumask *mask);
           void (*suspend)(struct clock_event_device *);
           void (*resume)(struct clock_event_device *);
           unsigned long           min_delta_ticks;
           unsigned long           max_delta_ticks;
           const char              *name;
           int rating;
           int irq;
           int bound_on;
           const struct cpumask    *cpumask;
           struct list_head        list;
           struct module           *owner;
        };

🫶 Members 🫶

okay bestie, member-by-member time. this is giving documentation but make it cute 🌸

• event_handler — the framework assigns this one, and the low level handler of the event source calls it. assigned-by-the-framework realness 💖
• set_next_event — set next event function using a clocksource delta ✨
• set_next_ktime — set next event function using a direct ktime value 🕰️
• set_next_coupled — set next event function for clocksource coupled mode 🔗
• next_event — local storage for the next event in oneshot mode 📦
• max_delta_ns — maximum delta value in ns, highkey important 🔥
• min_delta_ns — minimum delta value in ns, also important 💅
• mult — nanosecond to cycles multiplier 🧮
• shift — nanoseconds to cycles divisor, and it’s a power of two, bestie ⚡
• state_use_accessors — current state of the device, assigned by the core code 👑
• features — the description is literally just “features”, bestie. that’s the whole thing, and I respect the brevity 😭
• cs_id — Clocksource ID to denote the clocksource for coupled mode 🆔
• next_event_forced — True if the last programming was a forced event 💥
• retries — number of forced programming retries 🔁
• set_state_periodic — switch state to periodic 🌀
• set_state_oneshot — switch state to oneshot 🎯
• set_state_oneshot_stopped — switch state to oneshot_stopped 🛑
• set_state_shutdown — switch state to shutdown 🔌
• tick_resume — resume clkevt device ▶️
• broadcast — function to broadcast events 📣
• suspend — it’s in the struct above, but the Members blurbs don’t give it a separate description, so I’m not inventing one 🫠
• resume — same energy: struct field, no separate Members description, no cap 💀
• min_delta_ticks — minimum delta value in ticks stored for reconfiguration 🐜
• max_delta_ticks — maximum delta value in ticks stored for reconfiguration 🐘
• name — ptr to clock event name 🏷️
• rating — variable to rate clock event devices ⭐
• irq — IRQ number, only for non CPU local devices 🚨
• bound_on — Bound on CPU 📍
• cpumask — cpumask to indicate for which CPUs this device works 🧠
• list — list head for the management code 📋
• owner — module reference, gotta keep that module ref, periodt 🫶

🌈 SEE ALSO 🌈

• Kernel file ./include/linux/clockchips.h — go peek, bestie 🦋

and that’s the page! 🎀 this one lives under ./include/linux, dated October 2026, and it’s the struct clock_event_device(9) manual page — mwah 💋