Post Syndicated from Lennart Poettering original https://0pointer.net/blog/projects/s270ctrl.html

In response to mjg59‘s rant about
controlling the LCD brightness on laptops, I invested some time to
reverse engineer the Windows driver of my MSI S270 laptop
which implements changing LCD brightness. It requires some ugly
fiddling with registers of the “embedded controller” on ports 0x62 and
0x66. The result of my work is s270ctrl, a
small userspace utility. I’m planning to turn this into a proper
kernel module soon.