Enabling USB0 as device on AM437x GP EVM board.

Nishal Lingaraju

Intellectual 260 points

Hi ,

I am trying to enable USB0 of AM437x GP EVM board as hid device.

I read that by default USB0 is enabled in device mode and USB1 is enabled in Host mode.

But when I connect the board to pc through USB0 port , I don't see that device listed.

So Can anyone tell me what are configurations flags to be enabled in defconfig file or in menuconfig.

As of now I, while building , I enabled USB gadget as builtin and enabled USB hid gadget in it. I also tried enabling OTG support along with it. But Nothing seems to work.

Also let me know if I need to follow any more steps, or is there any thing more that needs to done which I may be missing.

Thanks in Advance,

Nishal

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi,

Check this wiki: http://processors.wiki.ti.com/index.php/Linux_Core_DWC3_User's_Guide#Driver_Configuration

0 Nishal Lingaraju over 10 years ago in reply to Biser Gatchev-XID

Intellectual 260 points

HI Biser,

Thanks for the link.But I had referred this earlier and built.

I have one doubt regarding .dtsi file. By default USB1 is configured as peripheral and USB2 as host. So I did not modify . Even after following these steps, pc is unable to detect the board as device. So should we do insmod after booting up the board.

Is there any other way to test if the USB0 port is configured as HID device on the board itself without connecting it to PC.

Thanks,
Nishal

0 Bin Liu over 10 years ago in reply to Nishal Lingaraju

TI__Guru**** 169801 points

Have you followed the instructions in kernel Documentation/usb/gadget_hid.txt? The kernel HID gadget driver cannot be used AS-IS, as it is missing the platform data, which is application specific. Please follow the document to at least implement struct platform_device providing struct hidg_func_descriptor.

To validate if your kernel config for USB0 is correct or not, please use other gadget driver, for exmaple, g_zero. If the host can enumerate it, then your kernel has no configuration issue, only you have to comlete the hid gadget implementation.

0 Nishal Lingaraju over 10 years ago in reply to Bin Liu

Intellectual 260 points

HI,

After booting the board, I did modprobe "g_zero" to load the module, then I connected the board to PC. But I don't see the device listed(gave dmesg -c and lsusb command on PC).

What does this behavior mean? While building the kernel gadget support were enabled as module. I am quite new to linux as well.

Thanks,

Nishal

0 Nishal Lingaraju over 10 years ago in reply to Nishal Lingaraju

Intellectual 260 points

Hi,

Thanks for the support. I tried to redo the same steps and was able to detect gadget zero on my PC.

Regarding the hid gadget implementation, I wanted a conformation is it we have to change descriptors in the hid.c( mentioned as platform data in the document).

Thanks.

0 Bin Liu over 10 years ago in reply to Nishal Lingaraju

TI__Guru**** 169801 points

Nishal Lingaraju said:
I wanted a conformation is it we have to change descriptors in the hid.c( mentioned as platform data in the document).

That is right. You also have to have a user space application to provide the HID input, the sample code hid_gadget_test in the kernel document is a reference.

0 Nishal Lingaraju over 10 years ago in reply to Bin Liu

Intellectual 260 points

Hi,

Thanks for the conformation.

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Enabling USB0 as device on AM437x GP EVM board.