Mostly it seems we are in understanding here, looking forward
to the patches...

On Thu, Nov 24, 2016 at 5:32 PM, Thierry Reding
[off-list ref] wrote:

On Thu, Nov 24, 2016 at 04:08:08PM +0100, Linus Walleij wrote:

quoted

I don't understand. Userspace should have no concern about the
numberspace. Lines can be named from DT or ACPI so you can
look up line chip+offset from the names.

Userspace would have to know about the numberspace if it wants to use
the character device, right?

No it shouldn't really. Adding gpio-line-names = "foo", "bar" etc
and following a reasonable naming policy (such as using the
rail names on the schematic, which is usually helpful) the
GPIO can easily be looked up from its name.

The chardev tries to overcome the hardships in finding the
GPIO you want this way.

Yours,
Linus Walleij