This adds support for the ADP588 GPIO expander from Analog Devices. It
is accessed over I2C and provides up to 18 pins. It is largely a port of
the Linux driver developed by Michael Hennerich
<michael.hennerich@analog.com>
Signed-off-by: Ian Roberts <ian.roberts@timesys.com>
Signed-off-by: Greg Malysa <malysagreg@gmail.com>
Signed-off-by: Vasileios Bimpikas <vasileios.bimpikas@analog.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>
Signed-off-by: Arturs Artamonovs <arturs.artamonovs@analog.com>
Signed-off-by: Oliver Gaskell <Oliver.Gaskell@analog.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@timesys.com>
