Linux/DRA712: USB ID Device tree configuration

Christian N

Part Number: DRA712

Tool/software: Linux

Team

Our custom board use usb2_dx and gpmc_wen.gpio2_25 as OTG port. We try enable it by Device Tree as detailed below

&usb2 {
   status = "okay";
   srp-disable;
   hnp-disable;
   adp-disable;
};

&omap_dwc3_2 {
   status = "okay";
   extcon = <&usb_id2>;
};

   usb_id2: usb_id2_extcon {
      pinctrl-names = "default";
      pinctrl-0 = <&pinctrl_usb_id2>;
      compatible = "linux,extcon-usb-gpio";
      id-gpio = <&gpio2 25 GPIO_ACTIVE_HIGH>;
   };

   pinctrl_usb_id2: usb_id2_grp {
      pinctrl-single,pins = <
         DRA7XX_CORE_IOPAD(0x34cc, (PIN_INPUT_PULLUP | MUX_MODE14))              /* gpmc_wen.gpio2_25 */
      >;
   };

We have several problems

USB ID pin (gpmc_wen.gpio2_25) has 0V (zero) level, but it is configured as GPIO (mode 0xE) with PULL UP
usb2_dX port is not working, it doesn't work as HOST (dmesg does't show any message when plugged it in any device and data lines doesn't start J/K USB protocol) nor DEVICE (several PC were tested but any activity was detected using PC dmesg). As HOST role we see that D+ rise to 3v3 and remains steady when device is plugged in

Are we missing anything?

over 6 years ago

0 Yordan Kamenov over 6 years ago

TI__Mastermind 42515 points

Hi Christian,

I have forwarded your question to USB expert.

Regards,
Yordan

0 Christian N over 6 years ago in reply to Yordan Kamenov

Expert 1285 points

Kernel

6AM.1.3
git.omapzoom.org/

0 Vishal Mahaveer over 6 years ago in reply to Christian N

TI__Mastermind 32830 points

Hi Christian,

Are below Kernel configs enabled?

CONFIG_EXTCON
CONFIG_EXTCON_USB_GPIO

Do you see any failures related to extcon or USB in Kernel boot logs?

Regards,
Vishal

0 Christian N over 6 years ago in reply to Vishal Mahaveer

Expert 1285 points

Hello Vishal

Custom kernel config fragment

...

CONFIG_EXTCON=y

...

CONFIG_EXTCON_USB_GPIO=y

...

I understand that the following messages are not errors, but they are the only strange thing that I could saw

[    3.620635] dwc3 48890000.usb: otg: primary host xhci-hcd.0.auto registered
[    3.627681] dwc3 48890000.usb: otg: shared host xhci-hcd.0.auto registered
[    3.634611] dwc3 48890000.usb: otg: can't start till gadget registers
[    3.853754] dwc3 488d0000.usb: otg: primary host xhci-hcd.1.auto registered
[    3.860752] dwc3 488d0000.usb: otg: shared host xhci-hcd.1.auto registered
[    3.867706] dwc3 488d0000.usb: otg: can't start till gadget registers

0 Vishal Mahaveer over 6 years ago in reply to Christian N

TI__Mastermind 32830 points

Yes, these logs are normal.

Instead of id-gpio, can you try changing the property to vbus-gpio

Snippet from Kernel documentation below (Documentation/devicetree/bindings/extcon/extcon-usb-gpio.txt)

Either one of id-gpio or vbus-gpio must be present. Both can be present as well.
- id-gpio: gpio for USB ID pin. See gpio binding.
- vbus-gpio: gpio for USB VBUS pin.

0 Vishal Mahaveer over 6 years ago in reply to Vishal Mahaveer

TI__Mastermind 32830 points

Also some additional info here
processors.wiki.ti.com/.../Linux_Core_DWC3_User's_Guide

0 Christian N over 6 years ago in reply to Vishal Mahaveer

Expert 1285 points

Doesn't work, and now D+ doesn't rise to 3v3

0 Vishal Mahaveer over 6 years ago in reply to Christian N

TI__Mastermind 32830 points

Issue has been resolved, schematics were not open to share publicly.

The issue was resolved after enabling gadget drivers. The otg state machine starts after registering a gadget driver in the Kernel.
ADB via ConfigFS is the default gadget driver in TI kernel and it is configured for USB1.

When 2 ports need to be configured as OTG, 2 gadget driver need to be registered.
After doing this the USB ports worked in OTG mode.

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Linux/DRA712: USB ID Device tree configuration