Hi, thank you very much!

It works now. I totally forgot to enable ldo3 and ldo4:)
I am using my custom board and i want to migrate from legacy 3.4 to 
mainline.

Thanks,
Milos

четвртак, 09. јул 2020. 19.06.05 UTC+2, Chen-Yu Tsai је написао/ла:
>
> Hi, 
>
> On Fri, Jul 10, 2020 at 12:51 AM Milos Ladni <[email protected] 
> <javascript:>> wrote: 
> > 
> > Hi, 
> > 
> > I am using mainline kernel on my A20 board and can not get GPIO working 
> for some ports. 
> > I tested them through standard sysfs and for pin number id i used next : 
> (position of letter in alphabet - 1) * 32 + pin number 
> > I tried with PE0, PE1, PE2, and PE4, i think that whole PE port does not 
> work. Pin is exported in /sys/class/gpioX and direction is set to 'out' but 
> when i write 1 or 0 to value nothing happens (actually it changed value for 
> 0.2~0.4V between logical 0 and 1). Pin numbers for that port was 
> (5-1)*32+pinNumber => 128 + pinNumber. 
> > In dtsi for A20 port E is by default intendent for CSI0 but CSI0 is not 
> enabled in my case and i also tried to completly remove SCI0 from linux 
> kernel and comment pin confiruration for CSI0 in dtsi file but it still 
> does not works. 
> > I noticed this issue because i use LVDS display and my display standby 
> pin is connected to PE2. 
> > After system is started i can login normally. After ~10 seconds i can 
> see only this message in dmesg: 
> > 
> > [   27.180481] random: crng init done 
> > [   31.896048] vcc3v0: disabling 
> > [   31.899038] vcc5v0: disabling 
> > [   31.902015] ldo3: disabling 
> > [   31.905150] ldo4: disabling 
> > [   31.908346] ahci-5v: disabling 
> > [   31.911416] usb0-vbus: disabling 
> > [   31.914644] usb1-vbus: disabling 
> > 
> > After this message PE2 goes to LOW and never come back to HIGH level. 
> > I also tried to completelly remove my LVDS display and i got the same 
> behavior for all pins on PE port. 
> > I also tried to connect PE2 to pull-up 3V3 through 10k resistor but 
> without success. After ~30 seconds after i turn on device PE2 goes LOW 
> forever. 
> > Interesting part is that when it is HIGH it is 2.8, not 3.3V. Maybe i 
> missed some configuration in dts file. 
>
> What board are you using? 
>
> Any board based on Allwinner's reference design will use one of the 
> LDOs at 2.8V to power the 
> PE and PG pin groups. This is because the two pingroups are almost 
> exclusively used for camera 
> sensors, which a lot of use 2.8V I/O levels. Now if you don't have 
> power for the pingroups, 
> i.e. the LDOs are off, then of course the pins don't work. 
>
> First check your schematics to see if that's the case. Then you need 
> to properly wire up 
> pin power supplies using the vcc-pX-supply properties in the pinctrl 
> node. See other newer 
> boards for how that works. 
>
> ChenYu 
>
> > Also tried PG1 and does not works. 
> > Tried PH18, PH21 and it works. 
> > Tried PB14 and it works. 
> > Another ports i did not tried. 
> > 
> > Interesting part is that because i enegled gpio debug in kernel setup i 
> always get message "gpio gpiochip0: Persistence not supported for GPIO XXX" 
> does not matter if if it is PE port which does not work or PH port which 
> works. 
> > 
> > Can someone check this issue or check my dts files? 
> > 
> > Thank you, 
> > Milos Ladicorbic 
> > 
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>  
>
>

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