Martin Bang Andersen

I2C3 on a custom imx53 board.

Discussion created by Martin Bang Andersen on Dec 6, 2011
Latest reply on Dec 7, 2011 by Martin Bang Andersen

Hi there,


I am having some issues getting the I2C3 working. Bus 1 and 2 are working flawlessly. The bus is connected to pads 


I have ensured no other alternate functions of these pads has been enabled by mistake and I have checked that the memory addresses, registers and clocks are correctly set up, which is the case as far as I can see.

I have enabled debug output in i2c-imx.c and the console output shows the following errors:

<7>i2c i2c-2: <i2c_imx_xfer>
<7>i2c i2c-2: <i2c_imx_start>
<7>i2c i2c-2: <i2c_imx_bus_busy>
<7>i2c i2c-2: <i2c_imx_xfer> transfer message: 0
<7>i2c i2c-2: <i2c_imx_write> write slave address: addr=0x70
<7>i2c i2c-2: <i2c_imx_trx_complete> Timeout
<7>i2c i2c-2: <i2c_imx_stop>
<7>i2c i2c-2: <i2c_imx_bus_busy>
<7>i2c i2c-2: <i2c_imx_bus_busy> I2C bus is busy
<7>i2c i2c-2: <i2c_imx_xfer> exit with: error: -110


This was what I expected because the signals on SDA/SCL lines of I2C3 is not as expected. The clock dutycycle is very short compared to I2C1 and I2C2 and the frequency is 200khz where it should be 100khz as declared in mxci2c_data and is used for all three busses. And finally the data line goes high after the firste to clock pulses.


Anybody seen something similar?


Best regards