I’m trying to get started with the Digi ME 9210 to do high-speed SPI reads and push them out over the network. I’m having a little problem understanding the documentation coming at this cold as my first embedded Linux work; I was wondering if people could correct my misconceptions, or even point me at a “Configuring an SPI device for dummies” walkthrough.
I’ve gotten a little turned around about what all needs to be done to enable SPI communication. I’ve set up a kernel project in DigiESP where I’ve configured SystemType.NS9xxxImplementations.SPIPort, DeviceDrivers.SPISupport, DeviceDrivers.SPISupport.Digins921xSPPIController. Am I missing anything there?
I’m using the Digi Connect ME/W1ME development board; I’ve thrown all the microswitches on SW1 from the RS232 side to the GPIO side (e.g. IO1 instead of DCD, IO2 instead of CTS, etc). Is that wrong?
Once I have the kernel loaded into the 9210, I can SSH in and look at /dev. There’s no /dev/spidevB.D, as described in the spidev.h file. There is a /dev/gpio/2 and /dev/gpio/9. Is /dev/spidevB.D supposed to be automatically generated? Or am I supposed to set up /dev/spidevB.d myself? Or am I supposed to be using the /dev/gpio instead?
Looking at the hardware layout, I’m having real problems figuring out which lines are the SPI lines. Page 34 of Connect_ME_Wi-ME_Hardware_Reference gives that chip select is GPIO, but other parts of the documentation indicate that GPIO is lines 1-9 i.e. there is no line 0. Is this just a difference between zero-indexing and one-indexing? Or am I looking at the wrong part of the documentation to figure out how to use P7? The Connect_ME_Wi-ME_Devboard_Schematic pointedly does not have a pinout for P7 (GPIO Port)
As I said, this is my first time with embedded Linux, so I’d appreciate even links to tutorials, which my weak google-fu is not uncovering. Thank you!