On 12/1/2013 7:42 PM, Bit Pusher wrote: > I am trying to use both the A/D and the high-speed PRU direct I/O. I have > the A/D working using Adafruit_BBIO.ADC and separately, I can write > directly using the PRU based on the TI examples and using a Device Tree > Overlay, but have not been successful using them concurrently yet. By using > cat /sys/devices/bone_capemgr.9/slots, I found that the commands in python > of >>>> import Adafruit_BBBIO.ADC as ADC >>>> ADC>setup() > loaded the cape-bone-iio-00A0.dtbo overlay > > as > > /lib/firmware\> cat $SLOTS > 0: 54:PF--- > 1: 55:PF--- > 2: 56:PF--- > 3: 57:PF--- > 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G > 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI > 9: ff:P-O-L Override Board Name,00A0,Override Manuf,cape-bone-iio > > I then attempted to remove the overlay by > > /lib/firmware\> sudo sh -c "echo -9 > $SLOTS" > /lib/firmware\> cat $SLOTS
Device tree overlays are generally a hack to try and convert the inherently static device tree mechanism into a sort of poor mans hot-plug infrastructure. The loading of overlays works mostly OK, but unloading an overlay is a very good way to make your system totally unstable and/or cause kernel panics. To unload a device tree overlay cleanly, you have to reboot. :( -- Charles Steinkuehler [email protected] -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
