[Arm-netbook] eoma68 router (qca9531)

[Luke Kenneth Casson Leighton]

okaaay so the plan is to restart the eoma68 router project, this time
with a pre-existing reference design based on the QCA9531.  that has a
PCIe interface, USB2 and a 5-port GbE *and* a 2x2 2.4ghz WIFI antenna.
full source is available for everything so it can be entirely libre
and RYF Certified.

the advantage of having an EOMA68 Card in the router should be clear:
the Card will have considerably more resources: RAM, CPU cycles etc.
meaning that VPNs can be done without high latency, yet take advantage
of the LAN capabilities of the 5-port... you could put in a MiniPCIe
Card (a *proper* one) e.g. a 3G/4G/LTE Modem, WIMAX, 802.11ac... blah
blah.

the tricky bit: connecting the EOMA68 Card to the QCA9531.  now, i
took a look at the Reference Design and i *really* do not want to
touch the layout for the GbE, WIFI or PCIe.  so i figured, why not
connect the EOMA68 USB2 host interface back-to-back with the QCA9531's
USB host?

turns out that something called the Cypress AN2720 can do exactly
that, and it comes up as a cdc_subset of the usbnet linux kernel
driver.  yay!  quick search online: the datasheet is publicly
available, easy to find on digikey. yay!

so i would assume, because it's not an actual 10/100 ethernet, that it
would run at (saturate) the full 480mb/sec of USB2.  so not quite GbE
speeds but pretty damn close.  yay!

anyway should be quite straightforward.

l.

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68