On Wed, 10 Mar 2021, Maximilian Luz wrote:

This series adds support for the Surface System Aggregator Module (SSAM)
HID transport subsystem.

The SSAM is an embedded controller, found on 5th- and later generation
Microsoft Surface devices. On some of these devices (specifically
Surface Laptops 1, 2, and 3, as well as Surface Book 3), built-in input
devices are connected via the SSAM. These devices communicate (mostly)
via normal HID reports, so adding support for them is (mostly) just a
matter of implementing an HID transport driver.

SSAM actually has two different HID interfaces: One (legacy) interface
used on Surface Laptops 1 and 2, and a newer interface for the rest. The
newer interface allows for multiple HID devices to be addressed and is
implemented in the first patch. The older interface only allows a single
HID device to be connected and, furthermore, only allows a single output
report, specifically one for the caps lock LED. This is implemented in
the second patch.

See the commit messages of the respective patches for more details.

Now queued in hid.git#for-5.13/surface-system-aggregator-intergration

Thanks,

-- 
Jiri Kosina
SUSE Labs