I2C multi-master

Hello Toradex Team,

Our CPU will be in suspend to RAM mode and will wake up from GPIO input, but in fact what we want is to wakeup from screen touch. Our custom carrier board will have a microcontroller, which can be also connected to the touch controller I2C , but this means that the I2C bus will be multi-master I2C.
Do you have any experience or background working with this on the imx8?
Is this feature included in the i2c kernel driver from the torizonOS version we’re using 6.5.0?


Hello @peterz,

The I2C controller on the Verdin iMX8M Mini/Plus modules supports a multi-master bus.
I can confirm the driver used for the I2C controller on Torizon OS and the Toradex BSP implements the appropriate checks for a multi-master bus, so your use case should work.

The I2C standard can deal with different frequencies, but matching the frequency of both masters on the bus may be a good idea. The default speed for the Verdin iM8M Mini/Plus I2C is 400 kbps (Fast mode).

Best Regards,

Thanks for fast reply @bruno.tx ,

I will give it a try then