On Thu, Jul 09, 2020 at 02:38:17PM -0700, Milos Ladni wrote:
> 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.

Sample patch for Olimex Lime2:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cd42ca0515d3952fc78a591618d57dd54f881d1f

> 
> 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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