Add Digium TE-820 Octo Span T1/E1 Controller

[smunaut]

trafficstars

It's pretty much the same card as the TE-420 already present on site just with 8 channels (but same driver and same architecture).

I tested that card on the RPI5 and it needs the same 32bit pci trick ( it's dtoverlay=pcie-32bit-dma-pi5 for the PI5 ), then it works fine.

[geerlingguy]

Do you have a good picture of the card we could use for it?

[smunaut]