| .open | open the device. |
| .close | close the device.. |
| .read | do an input operation. |
| .write | do an output operation. |
| .ioctl | do an I/O control operation. |
| .select | poll device for I/O readiness. |
| .stop | stop output on the device. |
| .mmap | map device offset to memory location |
| .reset | reinitialize device after a bus reset. |