On Fri, 04 May 2012 18:26:58 +0200
Alexander Stein [off-list ref] wrote:

Am Montag, 30. April 2012, 15:27:17 schrieb Preston Fick:

quoted

This fix contains several changes that allow toggling of GPIO on CP210x
devices that support it. Changes include:
* Added in part number support, necessary to see if the connected device
supports the GPIO functionality
* Added two IOCTLs and ioctl function to allow GET/SET of GPIO
* Added in new #defines for partnum support, new USB requests
* Changed "Config request types" section to contain more correct definitions
for request recipient

Signed-off-by: Preston Fick <redacted>

Do you actually need to create new ioctls? You also could support gpiolib and 
create a gpiochip for that.

See my follow up posting, and comment on that proposal.