The Kontron sl28cpld is a board management chip providing gpio, pwm, fan[..]
monitoring and an interrupt controller. For now this controller is used on
the Kontron SMARC-sAL28 board. But because of its flexible nature, it
might also be used on other boards in the future. The individual blocks
(like gpio, pwm, etc) are kept intentionally small. The MFD core driver
then instantiates different (or multiple of the same) blocks. It also
provides the register layout so it might be updated in the future without a
device tree change; and support other boards with a different layout or
functionalities.