snd_hdsp(4): RME HDSP 9632 and HDSP 9652 sound card driver.

Hi there,

if anyone has access to a RME HDSP 9632 or HDSP 9652 sound card and could 
possibly test it (you need a PCI 32bit slot, not PCIe) - please have look at 
my proposal for a new snd_hdsp driver:

https://reviews.freebsd.org/D45112

Summary:

Add a sound(4) bridge device driver for the RME HDSP 9632 and HDSP 9652
sound cards. These cards require a nowadays rare PCI 32bit (not PCIe)
slot, but still see use due to their value and wealth of features.
The HDSP 9632 is mostly comparable to the newer HDSPe AIO, while the
HDSP 9652 is similar to the HDSPe RayDAT. These HDSPe PCIe cards are
supported by the snd_hdspe(4) driver which was taken as a starting point
for development of snd_hdsp(4).

Implementation is kept separately due to substantial differences in
hardware configuration and to allow easy removal in case PCI 32bit
support would be phased out in the future.

The snd_hdsp(4) kernel module is not enabled by default, and can be
loaded at runtime with kldload(8) or during boot via loader.conf(5).
Basic operation was tested with both cards, not including all optional
cable connectors and expansion boards. Features should be roughly on par
with the snd_hdspe(4) supported cards.


The HDSP cards are quite capable both in terms of channel count and low 
latency (0.7ms min buffer size), and are often available second hand at a 
reasonable price now that PCI slots become a rarity.
BTW, PCIe -> PCI adapters are an option but can be problematic, the one from 
Startech is known to work.

Cheers

Florian