I am currently working on an embedded project and need fast access on GPIO to control a read/write line for SPI. Now i have my SPIDEV driver working fine and have written a userspace ‘driver’ which uses a combination of SPIDEV and sysfs GPIO. Now, my GPIO toggle for 2 16 bits words is ~140usecs, I would like to get this down a bit and was wondering if there is a faster way to control the sysfs filesystem than using a generic open/write combo?
Any help would be appreciated, I would also like to keep this in userspace if possible. I have read a bit about mmap but it seems that it’s a dodgy place to start exploring with the complexity of the omap chip.