Enabling USB_OTG_PWR on i.MX6 at u-boot

[vitaly_a]

Hello,

I want to read a memory stick plugged in to the OTG port of my custom i.MX6 board. On the board the USB_OTG_PWR is configured as KEY_ROW4(ALT2). When I use "usb start" command I see the EHCI controller initialized but no storage device found. So, my questions:

1) Does the usb driver enable VBUS power automatically or I need to enable it manually? If yes then how do I do that? Which register controls this signal?

2) Does the state of the OTG_ID signal affect the functionality?

Thanks,

Vitaly

[vitaly_a]

Hi Igor,

What about my first question about VBUS power? I checked the kernel code and it uses independent GPIO to external PMIC. I haven't find anything similar in u-boot.

Thanks,
Vitaly

[igorpadykov]

regarding GPIO, linux driver has more capabilites and supports

"otg" mode and HNP as described for example in

sect.39.3.11 USB OTG HNP and SRP Support  Documentation

Best regards
igor

[igorpadykov]

Hi Vitaly

for using memory stick with OTG it is necessary to have OTG_ID signal low

(it configures OTG as host), no need to enable it manually.

Best regards
igor