On Tue, May 27, 2014 at 1:25 AM, Linus Walleij [off-list ref] wrote:

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

quoted

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.

quoted

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.

quoted

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.

Thanks for the comments, I will fix these problems. Just some details
in terms of the register layout. I will break out the gpio to separate
device nodes as instructed, I will have to use the reg attribute to offset
bank registers. Please let me know if it is acceptable.

gfc_gpio_fl0              GFC42'h1701c00c
gfc_gpio_fl0_mux      GFC42'h1701c010
gfc_gpio_fl1              GFC42'h1701c018
gfc_gpio_fl1_mux      GFC42'h1701c01c
gfc_gpio_fl2              GFC42'h1701c024
gfc_gpio_fl2_mux      GFC42'h1701c028
gfc_gpio_fl0_od        GFC42'h1701c030
gfc_gpio_fl1_od        GFC42'h1701c034
gfc_gpio_fl2_od        GFC42'h1701c038

Yours,
Linus Walleij