Linux kernel space driver for Corsair Vengeance K90 Keyboard

A simple HID driver for the K90 keyboard. Current features are:

• Remapping the G keys
• Hiding other special keys
• Change backlight brightness
• Switch between hardware playback and software mode
• Switch between profiles
• Toggle the record macro LED

The K90 has three USB interfaces:

• Interface 0 handles control messages and send HID reports for special keys and macro playback.
• Interface 1 HID reports for multimedia keys (Consumer Control HID usage page).
• Interface 2 HID reports for regular keys.

hid-generic takes control of the K90 keyboard, you need to unbind it (at least for the interface 0 of the keyboard, it works well with interface 1 and 2).

sudo tee /sys/bus/hid/drivers/hid-generic/unbind <<< "0003:1B1C:1B02.XXXX"

Replace XXXX with the correct value for the first interface of the keyboard.

If the modules is installed on the system, udev loads the module thanks to modules aliases but hid-generic still take over, the device can be rebound with this rule:

ATTRS{idVendor}=="1b1c", ATTRS{idProduct}=="1b02", GOTO="corsair_k90"
GOTO="corsair_k90_end"

LABEL="corsair_k90"
ACTION=="add", SUBSYSTEM=="hid", ATTRS{bInterfaceNumber}=="00", RUN+="/bin/sh -c 'echo $kernel > /sys/bus/hid/drivers/hid-generic/unbind; echo $kernel > /sys/bus/hid/drivers/corsair/bind'"

LABEL="corsair_k90_end"

Parameters

Keycodes can be changed thanks to module parameters. Each parameter is a integer array (comma-separated) containing the keycodes (see linux/input.h).

• gkey_codes An array of 18 keycodes for remapping the G keys.
• recordkey_codes An array of 2 keycodes respectively for starting and stopping recording a macro.
• profilekey_codes An array of 3 keycodes for the M1/M2/M3 buttons.

Sysfs

• macro_mode (read/write) Switch playback mode. Values are "HW" or "SW".
• current_profile (read/write) Change the current profiles. Values are 1, 2 or 3.

LEDs

The driver create two devices in the led class for the backlight and the macro record led, respectively named ::backlight and ::record.

Profile

This driver does not expose any ABI for writing profile. You can use the user space program at https://github.com/cvuchener/k90-send-profile.