corsair-mode.py

#!/usr/bin/env python3
"""
Read the current performance mode of the Corsair AI Workstation 300.

ERAX MMIO region: 0xFEC40400 (SystemMemory, ACPI DSDT)
FCMO field at byte offset 0x31 — current mode output register.
Mapping confirmed from DSDT WMAA method (WMI method ID 2).
"""

import mmap, os, sys

ERAX_BASE   = 0xFEC40400
FCMO_OFFSET = 0x31

MODES = {
    0: "Balanced (~85W)",
    1: "Max      (~120W)",
    2: "Quiet    (~55W)",
    3: "Super",
}

def open_erax():
    page_size = 4096
    page_addr = ERAX_BASE & ~(page_size - 1)
    fd = os.open("/dev/mem", os.O_RDONLY | os.O_SYNC)
    m = mmap.mmap(fd, page_size, mmap.MAP_SHARED, mmap.PROT_READ, offset=page_addr)
    base = ERAX_BASE - page_addr
    return fd, m, base

def read_mode(m, base):
    return m[base + FCMO_OFFSET]

def main():
    fd, m, base = open_erax()
    try:
        if "--watch" in sys.argv:
            import time
            last = None
            print("Watching for mode changes (Ctrl-C to stop)...")
            while True:
                val = read_mode(m, base)
                if val != last:
                    label = MODES.get(val, f"Unknown ({val})")
                    print(f"Mode: {label}")
                    last = val
                time.sleep(0.25)
        else:
            val = read_mode(m, base)
            label = MODES.get(val, f"Unknown ({val})")
            print(f"Mode: {label}")
    finally:
        m.close()
        os.close(fd)

if __name__ == "__main__":
    main()