2016-05-04, 09:24 AM
(2016-05-03, 05:58 PM)Sailoog Wrote: oops, do you have any link or info?
Yesss,
On the old A/B the control was in :
/sys/devices/platform/bcm2708_usb/buspower
then to power ON|OFF simple commands was:
Poweroff
echo 0x0 > /sys/devices/platform/bcm2708_usb/buspower
Poweron
echo 0x1 > /sys/devices/platform/bcm2708_usb/buspower
Now on PI2/PI3 the cut off of power on usb sockets may be handled by:
/sys/devices/platform/soc/3f980000.usb
pi@raspb13:/sys/devices/platform/soc/3f980000.usb $ cat buspower
Bus Power = 0x1
On the simplest way you can see how is implemented the below library useful to control many usb controllers( and rpi too):
https://github.com/codazoda/hub-ctrl.c
Instead about GPU PM for BCM2835/BCM2836 please check the specific kernel ml:
https://lists.freedesktop.org/archives/d...00294.html
http://anholt.livejournal.com/45752.html
Davide