gumstix, i2c and lm-sensors

Today got the adm1025 && adm1026 hardware monitoring chips working with the gumstix i2c implementation.

First problem was that the adm1025 kernel driver was not generating any activity on the i2c pins. This problem was solved with a tiny adjustment to the i2c-pxa bus to let it support hardware monitor class devices.

Now loading the adm1025 driver generated some output but all transmissions resulted into bus errors, so it could not even start probing for the chip…. After staring at the scope output for an hour and wandering through the drivers, figuring why we kept getting those transmission errors, we finally ‘discovered’ we mixed up the sda and scl lines, because we could only use 1 of the scope’s 2 channels this slightly vital stupidity remained hidden to us… duh.
The last step was letting stuff run in i2c fast-mode (default is 100kHz). This only took setting the FM bit in the pxa’s ICR register.

et voila, all done.
patches are here

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: