HID: steelseries: Add MSI Raider A18 HX A9WJG RGB support

The MSI Raider A18 HX A9WJG exposes two internal SteelSeries USB HID
devices for RGB lighting: KLC (1038:1122) for the keyboard and ALC
(1038:1161) for the lightbar/logo zones.

Add DMI-gated support for these devices and expose them as multicolor
LED class devices. The driver sends the same HID class SET_REPORT
control transfer as the tested userspace implementation for this
machine and writes a uniform RGB value to all known keyboard keys or
ALC zones.

The ALC payload uses sparse LED IDs on this chassis: 0x00, 0x01,
0x02 and 0x03 are physical zones, while 0x04 and 0x05 do not appear
to map to physical LEDs. Unused payload LED ID slots are initialized
to 0xff so they are ignored by the controller instead of defaulting
to LED ID 0x00.

Limit RGB support to USB interface 0 and the tested DMI system because
the KLC product ID is shared across MSI laptop designs and the key
layout mapping is model-specific. If the DMI or interface check does
not match, keep the device bound as a regular HID device instead of
failing probe.

Also make the existing Arctis 9 vendor usage-page check defensive by
returning false for report descriptors shorter than three bytes before
inspecting hdev->rdesc[0..2].

Tested on MSI Raider A18 HX A9WJG. Both internal SteelSeries ALC
(1038:1161) and KLC (1038:1122) HID devices bind on interface 0 and
create steelseries::lightbar and steelseries::kbd_backlight. Setting
multi_intensity and brightness changes the keyboard and lightbar
colors.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606010709.X0QYNjFZ-lkp@intel.com/
Signed-off-by: David Glushkov <david.glushkov@sntiq.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

0 files changed, 0 insertions, 0 deletions