On Fri, Aug 25, 2017 at 1:50 AM, Stuart Longland
[off-list ref] wrote:

[Note: dropping vadimp at maellanox.com as SMTP server complained about the
DNS server returning NXDOMAIN.  Apologies.]
On 25/08/17 18:32, Linus Walleij wrote:

quoted

Gnah!
Whoever writes a slot-in replacement making the character device
take precendence wins lots of karma.

What would such a replacement look like though?

See Linus's comments about using the existing kernel GPIO chardev
interface.  It already supports requesting multiple GPIO line state
changes in a single request.

Some sort of system whereby you can read/write single-line commands as
if talking to a GPIO expander over a UART?

Would you access the GPIOs one by one, or would you perhaps map them
into a bitmap (maybe arbitrarily, up to 64-bits wide) and perform masked
operations on the bitmap?

I'm no fan of the sysfs GPIO interface, but it beats poking around at
registers behind the kernel's back.
--
Stuart Longland (aka Redhatter, VK4MSL)

I haven't lost my mind...
  ...it's backed up on a tape somewhere.