I'm looking to work on some suspend functionality on a Dragonboard410c that has the USB hub and HDMI bridge removed in order to check how much power the part uses while sleeping. Reading here and here, it seems like Qualcomm has no plans to add suspend to the boards but in the interest of getting some work done, I was wondering if there was any documentation on the PLL/RAM setting registers so that I can add that functionality myself?
I've verified that the board uses about 40mA when in the 'freeze' state, but that isn't quite enough for our application.
I was actually digging around the Android source to see how they were going into the deeper sleep but couldn't find the source.
Variscite claims that they can get down to 4mA with their SOM and I would like to verify that. They too are just using the Debian Linaro distro, same as the Dragonboard.
 - https://discuss.96boards.org/t/does-db410c-support-suspend-resume-functions/1066
 - https://discuss.96boards.org/t/dragonboard-power-measurements/2442
 - http://www.variscite.com/products/system-on-module-som/cortex-a53-krait/dart-sd410-qualcomm-snapdragon-410