Recommendation of simple SPI device


I am writing some example codes to study linux device driver & kernel :

I plan to fill this repository by implementing from simple driver to complex one which uses many kernel features such as interrupts.

By the way, I wrote a simple driver which takes advantage of the I2C subsystem and, because the purpose of the examlle is to i2c itself, the driver only contains some code for simple RTC register reading.

Now, I want to write the same one but uses SPI. However, most SPI-interfaced devices are too complex that they are not sufficient to test SPI itself: I have to write the whole device driving code, which is out of the purpose of the example.

So it would be very appreciate if someone can recommend a very simple SPI device.

Thank a lot!
Best regards

Heecheol Yang.