Friday 12 July 2013

pinmux issue resolved

Just a quickie update to say that I have overcome an issue I had last week. In my last report, I wrote that I had an issue configuring the I2C pins for the third I2C bus on the BeagleBone Black (AM335X). The root cause was that writes to the control module registers on the Cortex-A8 must be done in privileged mode and my driver runs in user space. I moved the pin configuration into the kernel and it executes as part of the arm specific initialization now. Now that the pins are getting setup properly, my driver works for the third I2C bus. Here's the output of my eepromread utility reading an EEPROM I attached to the third I2C bus:

This change is just a temporary fix until another developer gets a chance to create a pinmux server. With Minix being a microkernel based operating system, we try to keep the amount of code in the kernel to a minimum.

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