For anyone following this thread, Alan's suggestion was 100% on. My driver
now works!
Thanks to everyone who helped.
Chris
--------------------------------------------------
From: "Alan Stern" <stern@xxxxxxxxxxxxxxxxxxx>
Sent: Tuesday, September 06, 2011 4:48 PM
To: "Chris Furlough" <chrisfurlough@xxxxxxxxxxx>
Cc: "Greg KH" <greg@xxxxxxxxx>; <linux-usb@xxxxxxxxxxxxxxx>
Subject: Re: HID device question.
On Mon, 5 Sep 2011, Chris Furlough wrote:
Alan, I'm learning as I go on this stuff.
Let me tell you what I need to do, and if you can tell me the proper way
to
take over the file ops, I'll do that, and I believe I can handle the rest
on
my own.
Client applications will use libusb to talk to the device.
The device may be inserted before the driver is loaded, in which case it
will be claimed by the HID driver. (It ISN'T a HID device, and doesn't
support the "reports" interface. All communications are accomplished
through the IOCTLS issued from inside libusb.)
That being the case, I need to take over the IOCTL "vector" for
communications with the device. Open, Release, Read, Write, can all stay
the same.
I would gladly accept API references, pointers to example code, etc.
I'm not particularly familiar with the chardev interface -- the Linux
Device Drivers book is probably a good place to start.
I think what you need to do is overwrite the file ops pointer in
usb_device_cdev. Your new file_operations can be the same as the
existing one, all except for the ioctl method pointer.
Alan Stern
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
