USB 2.0 3.0 OTG Serial Gadget LS1021A TWR Board

[jiye]

Hi,

I am trying to configure USB 2.0 (A) or USB3.0(B) as serial port on the eva board of LS1021ATWR. I know USB3.0 (B) has USB2.0 in it, and there is another USB2.0 (A) see Figure 2-9

I said USB2.0 as A here to indicate this is only USB2.0 controller not the USB2.0 in USB3.0

I said USB3.0 as B here to indicate USB3.0 controller which has both USB3.0 and USB2.0

Correct me if I am wrong

From the TWR-LS1021A reference manual. I found

Seems like if I want to use USB1 (USB3.0 which contains USB2.0) to achieve serial access I need to get rid of the HUB on the board? what if I need to use USB2 to achieve serial access.

I assume these two pins are either (D21 and D22)  or (D23 and D24) is USB 2.0 all I need to do is to connect the usb 2.0 cable wires (4 in total) , D+ and D- to these two pins.

Now question comes to what do I need to do to configure the USB 3.0 (B) or USB 2.0 (A) to serial port.

I already enabled necessary modules from the kconfig.

(1)what do I need to modify in the device tree file ?

the one @8600000 is USB1 or USB2 from Figure 2-9? It says host which is not the right mode for serial.

(2) what do I need to do to make USB3.0(B) acting like serial port?

(3) what do I need to do to make USB2.0(A) acting like serial port?

(4) if (2) is available how do I test it ?

[yipingwang]

Hello Elias Bitbaker,

It's impossible to use device (or Gadget) mode on LS1021ATWR, because there is a USB hub on this board.

If you want to use USB gadget, you could refer to the design of LS1021AQDS.

Thanks,

Yiping

[jiye]

also if I remove the USB hub from the LS1021a-TWR, can I use the USB gadget by connecting wires on the edge of the board D port ?

[yipingwang]

You could use USB gadget mode if removing USB hub in your design.

[jiye]

when you mention the usb hub are you talking about the U29 or the part U20B and U20C from the schematic 

[yipingwang]

Please refer to the attached patch to Disable all USB3 ports on all root hubs and Power on USB2 root hub ports only.

[jiye]

(1) can I use the USB2.0 from the secondary pin connector D port on the edge of the board ? If so can i configure the usb2.0 as Ethernet gadget?

(2) is this picture above for USB2.0 ?

[jiye]

i can't find anything about LS1021AQDS, can you share me a link with this board's datasheet?