On Wed, May 21, 2014 at 1:54 AM, Feng Kan [off-list ref] wrote:

I see each bank as separate gpio chip. It is a simple way to
abstract the banks since they can operate independently.

I think they should also be separate devices, and separate nodes
in the device tree.

It also
provided me a way to fix the sysfs gpio base number, regardless if
a particular bank node is pulled out.

The GPIO sysfs is unpredictable for this and many other
reasons and should not be relied upon.

This is also done in similar way
in some other gpio drivers such as the dwapb gpio driver.

I think the dwapb has it's registers mingled while your banks
seem to be separate chunks.

Yours,
Linus Walleij