Use USB OTG in host mode

[frm]

Hi,
Can I change the configuration of the microUSB OTG in my OLinuxino A64 to use it in "host mode" instead of "pheripheral mode" ?

I only found this post https://www.olimex.com/forum/index.php?topic=4990.0 which mentions a FEX file somewhere... and it's dated 2016

Thanks

[LubOlimex]

Hardware-wise it is possible since there is USB0-ID wire/signal. So the port supports both device and host mode, it is real OTG.

Software-wise I don't think the Olimage image supports it, so some changes to the image are required.

The info you found applies to older sunxi-based images, that used fex files, it does not apply to the Olimage Linux which uses mainline. You'd have to edit dts/dtb. Refer to the Olimage guide, there is info on how to change dts/dtb or kernel:

https://raw.githubusercontent.com/OLIMEX/OLINUXINO/master/DOCUMENTS/OLIMAGE/Olimage-guide.pdf

[frm]

Software-wise I don't think the Olimage image supports it, so some changes to the image are required.

This is really a pity. Right now I don't want to go through the lengthy process of rebuilding the kernel and the image myself, so I'll just use a basic USB hub to expand the single USB host port. It makes the whole setup much less compact thought :-(

Thanks

[winfried]

Since also need this for my A64 Rev.E , to connect a keyboard on the mini USB-OTG, USB-A already used by another device:

You'd have to edit dts/dtb. Refer to the Olimage guide, there is info on how to change dts/dtb or kernel:

Installed the crosscompiler and can make dtb. So what I have to edit ?

found in arch/arm64/boot/dts/allwinner/sun50i-a64-olinuxino-1G.dts

Code Select Expand

&usb_otg {
        dr_mode = "otg";
        status = "okay";
};

I cannot figure out what to change, or what mode to define and where to find the documentation for this.

Any hint ?

mfg winfried