Research: On the Toradex website they write that subject chip is "connected to GMI bus" (which could be "General Memory Interface"). I couldn't find anything about "GMI bus" in google, and I assume this is the same as "platform bus". Is this correct?
Ok, if so, we have the following: there are drivers in Linux
sja1000_platform.c which should be what I need, in addition to
can-dev drivers. But they can't be started (not even probed), because the kernel doesn't know about subject platform device.
All "platform" devices are added with their resources from the "board driver"
platform_add_devices() func. The problem is that it initializes all the devices from Colibri T20 and not the CAN chip which is on Eval Board.
So finally, if all above is correct, to bring up the drivers, I need to create a
platform_device structure with the array of
resource structures inside it with exact numbers of IRQs and memory addresses. I've been pointed to the controller's datasheet, but I don't know how tio extract useful information from it.
Where do I go from there? How can I declare the controller to the board driver? Recommendations of articles or books are welcome.