The SPI drivers are already part of the kernel. Look on this mailing list for reverences to spidev.
You can easily write a user application to talk out the SPI using the spidev driver. Read the sections on using spi in the /Documentation/spi/ directory of the Linux kernel.

Note that the CS line in only asserted during the actual transfer of bytes on the SPI bus. This is a very short time, you may not be able to see it at all unless the program sends data continuously.

On Thu, May 27, 2010 at 2:55 PM, AJ ONeal <Alvin.ONeal@gmail.com> wrote:
I'm trying to create the hardware equivalent of a "Hello World" example for the SPI driver using an LED.

I want to write a driver in just a few lines of code that when loaded will flip the Cable Select bit, turning on the LED which is attached along that path, but I'm not sure where to start.

This is my step from computer programming to computer engineering. I'm okay with compiling a kernel and (soft) software, but I've never written a driver before.

Links, comments, and clarifying questions welcome.

AJ ONeal


gumstix-users mailing list

This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the sender. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the company. Finally, the recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email.