Writing a PCIe-Driver

[Dr. Rolf Jansen]

Hello,

A couple of years ago, with the valuable help of people on this list, I managed to write a PCI driver for the National Instruments DAQ card, NI PCI-6251. The driver was kept very simple, only map the BAR’s and some DMA memory into the user space. The DAC/ADC and DIO is then all controlled from user space by writing command codes to certain offsets from the mapped BAR’s, and reading data from the mapped DMA memory and/or from other given offsets.

See: How to map device addresses into user space
https://lists.freebsd.org/pipermail/freebsd-drivers/2013-January/thread.html


Now, I need to do exactly the same for a PCIe card, namely the NI PCIe-6351. However, I even cannot see where to start. For PCI cards, the respective chapter 11 in the FreeBSD Architecture Handbook was quite helpful, for getting started, in no time, I got the PCI card probed and attached.

https://www.freebsd.org/doc/en_US.ISO8859-1/books/arch-handbook/pci.html

The dumb approach, probing the device ID and attaching the PCI(e) driver to the PCIe device in a similar fashion didn’t work - I didn’t expect this either, however, where would I start? How do I attach my driver to a PCIe card on FreeBSD 11 or 12?

Please can somebody push me into the right direction. Once I got the driver attached to the card, I guess, I would be able to adapt the mem-mapping code of my old driver for the new card.

Best regards

Rolf