Hi,
On Thursday, 22.03.2018 at 20:47, André Przywara wrote:
> > Ok, I just measured both ports (via a cannibalised USB cable + OTG for the
> > micro-USB) and there's no power on either of them. Cross-checked the
> > measurement setup against an old Thinkpad to be sure.
One more data point which I did not notice before: After ATF runs but
before the kernel boots I get 5V (well, 4.85V but close enough) on the
USB-A port. Once the kernel has booted the voltage drops to zero.
> OK, remote debugging!
>
> Can you please try to play around with GPIO PG9 from Linux? Basically:
> # cd /sys/class/gpio
> # echo 201 > export
> # cd gpio201
> # echo out > direction
> # echo 1 > value
>
> And then try to measure the USB voltage again? Try 0 for "value" as
> well. If the export complains, try to remove the DT parts I gave you
> (switch back to the normal mainline DT). 201 is ('G'-'A') * 32 + 9.
> Something like that should enable the voltage on the USB-A socket
> (regardless of the DT used).
I seem to be missing some driver for the GPIOs as I have no
/sys/class/gpio and nothing that looks suitable in /lib/modules; what do I
need to add to the arm64 defconfig to enable this?
> For the micro-B port: Can you try to add the following line to the ATF
> source, into plat/sun50iw1p1/sunxi_power.c, somewhere in the
> pmic_setup() function:
> sunxi_pmic_write(0x30, sunxi_pmic_read(0x30) | BIT(2));
>
> That should power the DRIVEVBUS/N_VBUSEN pin, ideally turning on the
> power of the OTG port.
> If that works, I can make a Linux patch to do this there as well.
When I add that line to ATF I get 5V on the micro-B port after
initialisation and it stays powered up even after the kernel has booted.
Cheers,
-mato
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