The Intel ISH is an on-package sensor hub used on some systems in place of external sensor hubs. The ISH provides sensors like detecting device rotation, automatic backlight adjustment, and can also be responsible for some low-power sleep states. This is for Cherrytrail and newer, including some Skylake notebooks.
The Intel Integrated Sensor Hub has been supported by Android's Linux kernel while with v4.9 it's finally coming to the mainline kernel. The user-mode ABI is exposed the same via Linux IIO so all existing user-space software should be compatible with this Intel sensor hub.
Two of the devices using ISH that have been tested with the new intel-ish-hid driver include the Lenovo Yoga 260 and HP Pavilion x2.
The Intel ISH support is being pulled into the mainline Linux 4.9 kernel via the HID subsystem. This HID pull also has a big cleanup to the Wacom driver and other HID fixes/improvements.