Adjust Intel GFX backlight using Rw.exe

intel_backlight.py

#!/usr/bin/env python3
# Intel Backlight Hack
# CC0 2018 Taeyeon Mori aka /u/Haruha

# Must be absolute!
rw_path = "D:\\Development\\Win32-Intel-Backlight\\Rw-Everything\\Rw.exe"

# Actuall Rw batch code follows
rw_code = """\
Read Intel GFX BAR1
> Local0 = rPCIe32(0, 2, 0, 0x10)
Null out flags to get address
> Local1 = and(Local0, 0xFFFFFFFFFFFFFFF0)
LVX offset = 0xC8254
See https://github.com/RehabMan/OS-X-Intel-Backlight/blob/master/IntelBacklight/IntelBacklightHandler.cpp#L39
> Local2 = or(Local1, 0xC8254)
Get LVX
> Local3 = r32(Local2)
Get max brightness
> Local4 = shr(Local3, 16)
Get relative brightness
> Local5 = mul(Local4, {level})
> Local5 = div(Local5, 100)
Construct new LVX
> Local6 = shl(Local4, 16)
> Local6 = or(Local6, Local5)
Write to hardware
> w32 Local2 Local6
"""

rw_exit_code = "> RwExit"


import sys
import ctypes

def is_admin():
    try:
        return ctypes.windll.shell32.IsUserAnAdmin()
    except:
        return False


if not is_admin():
    # Re-run the program with admin rights
    ctypes.windll.shell32.ShellExecuteW(None, "runas", sys.executable, " ".join([__file__] + sys.argv[1:]), None, 1)
    
    sys.exit()


import os
import argparse
import subprocess
import tempfile

parser = argparse.ArgumentParser()
parser.add_argument("level", help="New Backlight level", choices=list(range(0,101)), type=int, metavar="0-100", nargs="?")
parser.add_argument("--noexit", action="store_true", help="Don't exit Rw after running the script")
parser.add_argument("--pause", action="store_true", help="Pause after execution")
args = parser.parse_args()

if args.level is None:
    print("Enter new brightness level in %, or \"x\" to abort")
    while True:
        print("Brightness: ", end="")
        v = input()

        if v.lower() == "x":
            print("Aborted")
            sys.exit(12)
        
        try:
            args.level = int(v)
        except ValueError:
            continue
        else:
            if args.level <= 100 and args.level >= 0:
                break

with tempfile.NamedTemporaryFile("w", delete=False) as f:
    f.write(rw_code.format(level=args.level))
    
    if not args.noexit:
        f.write(rw_exit_code)
    
    path = os.path.dirname(f.name)
    name = os.path.basename(f.name)

subprocess.run([rw_path, "/Command=%s" % name], cwd=path)

os.unlink(os.path.join(path, name))

if args.pause:
    print("Press enter to continue")
    input()