The design uses Petalinux OpenAMP primarily as a data engine using the Ethernet port to process data and deliver to the microheader. So the MicroZed is a daughter card on a custom PCB that receives the processed data.
However we are also attempting to use the PMOD to connect to an I2C and a GPIO device.
The standard driver for the Zynq PS I2C controller under PetaLinux is Cadence I2C_cadence which operates the PS I2C controller through its registers.
Well the user level /dev/i2c0 writes were not working, so I added a custom module with the i2c_cadence as the basis and connected it to the I2C0 controller in the device tree to see how the driver was failing.
What I found using debug trace is that the I2C controller registers are not connected to their specified address 0xE0004000. Somehow its addresses on the IOP are not mapped. Regardless of what is written all the R/W registers read 0, and obviously the I2C controller function was not being executed.
Other peripherals on the IOP range of addesses UART, ENET work fine.
I am using Vivado 2016.2 and Petalinux 2016.2. The I2C0 is selected on MIO 14, 15 for SCL and SDA respectively, and the device tree specifies the normal 0xE0004000 as the register address for the controller.
Has anyone encountered this and found their mistake? Or any other suggestions?
