Need Kernel Driver Help

[pauldemet]

I am rather new to Linux and kernel programming. I am in the process of writing a driver for a new PCIe device. Everything seems fine until I attempt to open the device.

I am able to build and install the driver. I am creating a char device and accessing the driver through ioctl calls. The device can be seen in the /dev directory.

ls - l /dev | grep pxm:
crw-rw-r-- 1 root staff 125, 0 2010-11-29 09:01 pxmuio96a

All resources requested have been successfully obtained.

When I execute
dev_handle = open(device_id, O_RDWR) // device_id = "/dev/pxmuio96a"
the return value is -1.

It appears to me like the open routine is not being linked to my device. The device structure is:

struct file_operations pxmuio96_fops = {
owner: THIS_MODULE,
open: pci_device_open,
release: pci_device_release,
ioctl: pci_device_ioctl,
};

I have been chasing this for days. Any help would be greatly appreciated. Thanks.

[pauldemet]

Digging a little deeper, I have determined that I am getting errno = 6 (ENXIO), which is "No such device or address". Don't understand this since I can see the device and am using the same name in the open statement.

[Rubberman]

Put some printk() statements in your code to output log data to see what your kernel module is doing when you try to open the device.