PROCESSOR-SDK-AM62X: PROCESSOR-SDK-AM62X_dts

Hi Bin Liu,

I am facing an issue with enabling USB0 in peripheral mode on my [target board name]. I have loaded all the USB-related modules, but my PC is not detecting the target board through USB. Here are the details:

Kernel Version: linux-5.10.168

 Board: am62a7

Device Tree Settings:

&usbss0 {

status = "okay";

ti,vbus-divider;

};

&usb0 {

dr_mode = "host";

pinctrl-names = "default";

pinctrl-0 = <&main_usb0_pins_default>;

};

main_usb0_pins_default: main_usb0_pins_default {
pinctrl-single,pins = <
AM62AX_IOPAD(0x0254, PIN_INPUT, 0) /* (C20) USB0_DRVVBUS */
>;
};

Modules Loaded:

# lsmod | grep usb
usb_f_acm 16384 2
u_serial 20480 1 usb_f_acm
usb_f_fs 49152 3
usb_f_rndis 32768 2
u_ether 28672 1 usb_f_rndis
libcomposite 61440 13 usb_f_rndis,g_serial,usb_f_fs,usb_f_acm
usbcore 266240 3 xhci_hcd,ehci_hcd,xhci_plat_hcd
udc_core 32768 7 usb_f_rndis,u_ether,u_serial,libcomposite,usb_f_fs,usb_f_acm,dwc3
usb_common 16384 6 xhci_hcd,usbcore,libcomposite,xhci_plat_hcd,dwc3,udc_core

Output of /sys/class/udc:

# pwd
/sys/class/udc
# ls
# (no output)

# lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0003

Steps Taken:

1. Loaded all USB-related modules.
2. Checked the device tree settings.

Despite these steps, the PC is still not detecting the target board. There is no UDC listed under /sys/class/udc.

Questions:

1. Is there anything specific I need to change in the kernel or device tree to enable USB0 in peripheral mode?
2. Are there additional configurations or modules I might be missing?
3. How can I debug this issue further to identify why the UDC is not showing up?

Any help or suggestions would be greatly appreciated.

Thank you!

Laxman B said:

&usb0 {

dr_mode = "host";

Are you connecting USB0 to PC? If so your kernel dts sets USB0 in host mode, PC won't detect it.

Laxman B said:

Is there anything specific I need to change in the kernel or device tree to enable USB0 in peripheral mode?

As I said, the SDK by default configures USB0 in dual role mode, which supports USB as peripheral. You don't have to change any config.

Laxman B said:

Are there additional configurations or modules I might be missing?

Likely not, since your USB0 works in host mode. You just need to ensure the USB gadget driver, which you intend to use, is enabled.

Laxman B said:

How can I debug this issue further to identify why the UDC is not showing up?

As I said, your USB0 is not in device mode.

Hi Bin Lu,

I have already loaded the g_serial gadget module but am unsure how to verify that USB0 is indeed operating in peripheral mode.

# dmesg | grep g_serial
[ 209.266630] udc-core: couldn't find an available UDC - added [g_serial] to list of pending drivers

# lsusb
Bus 001 Device 001: ID 1d6b:0002
Bus 002 Device 001: ID 1d6b:0003

# ifconfig usb0
usb0: error fetching interface information: Device not found
#

Despite these steps, I am not certain if USB0 is correctly configured as a peripheral. Could you please provide guidance on:

Additional steps or commands to verify USB0 is in peripheral mode?

Thank you for your assistance.

Best regards,

Laxman

Inquiry about "failed to enable ep0out" Error with DWC3 USB Gadget

Hello Bin Lu,

I'm encountering an issue with the DWC3 USB controller. When attempting to use the g_mass_storage gadget or g_serial gadget, I consistently receive the following error in the kernel logs:

[ 862.883326] dwc3 31000000.usb: failed to enable ep0out

Details:

1. Setup and Configuration:

   • I have configured the USB0 interface in peripheral mode in the device tree as follows

• &usb0 {
• dr_mode = "peripheral";
• pinctrl-names = "default";
• pinctrl-0 = <&main_usb0_pins_default>; };

Module Loading:

• When loading g_mass_storage with /dev/mmcblk1 as the file:

[ 862.833565] registering udc driver.
[ 862.837915] Mass Storage Function, version: 2009/09/11
[ 862.843356] LUN: removable file: (no medium)
[ 862.848062] LUN: file: /dev/mmcblk1
[ 862.855067] g_mass_storage gadget: Mass Storage Gadget, version: 2009/09/11
[ 862.870380] g_mass_storage gadget: g_mass_storage ready
[ 862.875930] udc driver binding ret:0
[ 862.883326] dwc3 31000000.usb: failed to enable ep0out

Similarly, g_serial gadget also encounters the ep0out error:

[ 535.629467] registering udc driver.
[ 535.634217] g_serial gadget: Gadget Serial v2.4
[ 535.639068] g_serial gadget: g_serial ready
[ 535.643436] udc driver binding ret:0
[ 535.652452] dwc3 31000000.usb: failed to enable ep0out

Further Information:

• I have verified the device tree configuration (dts) and kernel configuration (config) for USB gadget support (CONFIG_USB_GADGET, CONFIG_USB_DWC3, etc.).
• The gadget modules (g_mass_storage and g_serial) load successfully, but the ep0out endpoint fails to enable.\

Laxman,

I feel that both of your latest posts have conflict messages, and the second post has a lot of noise, and improperly formatted. I am having a hard time to form a clear picture of the issue you have.

Can you pleas edit both posts to describe the problem clearly?

Hi Bin Liu,

I hope you're doing well.

First, I want to apologize for any confusion caused by my previous messages. I realize they might not have been clear, and I appreciate your patience.

I'm encountering an issue with the UDC binding while configuring USB gadget drivers using ConfigFS in the latest version. In the past, I managed to get UDC binding working with the older version by simply loading the g_ether module. However, with the new version and the ConfigFS interface, I'm seeing the following error in dmesg:

[ 51.029853] registering udc driver.
[ 51.155890] udc driver binding ret:-19
[ 51.159889] udc 31000000.usb: failed to start g: -19
Here's the ConfigFS script I'm using:

Below script i'm using binding udc driver:

#!/bin/sh

# Check if script is running as root
if [ "$(id -u)" -ne 0 ]; then
echo "This script must be run as root"
exit 1
fi

# Move USB IRQ to Core 3
USB_IRQ=$(awk '/usb/ {print $1}' /proc/interrupts | sed 's/://g')
if [ -n "$USB_IRQ" ]; then
echo "Found USB IRQs: $USB_IRQ"
for IRQ in $USB_IRQ; do
IRQ_PATH="/proc/irq/$IRQ/smp_affinity"
if [ -e "$IRQ_PATH" ]; then
echo 8 > "$IRQ_PATH"
echo "Set IRQ $IRQ affinity to Core 3"
else
echo "smp_affinity file not found for IRQ $IRQ at $IRQ_PATH"
fi
done
else
echo "No USB IRQs found"
fi

# Load necessary kernel modules
modprobe libcomposite
modprobe usb_f_rndis
modprobe usb_f_fs
modprobe usb_f_acm
modprobe usbcore
modprobe ehci_hcd
modprobe xhci_hcd

# Mount the configfs filesystem
mount -t configfs none /sys/kernel/config

# Create and configure the gadget
cd /sys/kernel/config/usb_gadget/
mkdir g && cd g

# Set up USB gadget descriptors
echo 0x099E > idVendor # Trimble
echo 0x0004 > idProduct # Trimble USB Product ID
echo 0x0100 > bcdDevice # v1.0.0
echo 0x0200 > bcdUSB # USB 2.0

echo 0xEF > bDeviceClass
echo 0x02 > bDeviceSubClass
echo 0x01 > bDeviceProtocol

# Set up gadget strings
mkdir -p strings/0x409
echo "Trimble" > strings/0x409/manufacturer
echo "Alloy" > strings/0x409/product

# Create functions for serial, network, and MTP
mkdir -p functions/acm.usb0 # serial
mkdir -p functions/rndis.usb0 # network
mkdir -p functions/ffs.mtp # mtp

# Create configuration and link functions to it
mkdir -p configs/c.1
echo 250 > configs/c.1/MaxPower
ln -s functions/rndis.usb0 configs/c.1/
ln -s functions/acm.usb0 configs/c.1/
ln -s functions/ffs.mtp configs/c.1

# Set up FunctionFS for MTP and start the service
mkdir /dev/ffs-mtp
mount -t functionfs mtp /dev/ffs-mtp

# Check if FFS mount was successful
if [ $? -ne 0 ]; then
echo "Failed to mount FunctionFS for MTP"
exit 1
fi

# Start the umtprd service
/usr/sbin/umtprd > /dev/null &
if [ $? -ne 0 ]; then
echo "Failed to start umtprd service"
exit 1
fi

# OS descriptors
echo 1 > os_desc/use
echo 0xcd > os_desc/b_vendor_code
echo MSFT100 > os_desc/qw_sign

echo RNDIS > functions/rndis.usb0/os_desc/interface.rndis/compatible_id
echo 5162001 > functions/rndis.usb0/os_desc/interface.rndis/sub_compatible_id

ln -s configs/c.1 os_desc

# Ensure all configurations are set before binding
udevadm settle -t 5 || :

# Bind the UDC driver
ls /sys/class/udc/ > UDC
if [ $? -ne 0 ]; then
echo "Failed to bind UDC driver"
exit 1
fi

echo "USB gadget setup complete"

Despite following the steps, the UDC binding fails with the error code -19. Could you please help me understand what might be causing this issue and how I can resolve it?

Thank you in advance for your assistance.

Best regards,

Laxman

Hi Laxman,

Thanks for the new details. It is much cleaner!

Laxman B said:

In the past, I managed to get UDC binding working with the older version by simply loading the g_ether module. However, with the new version and the ConfigFS interface, I'm seeing the following error in dmesg:

Let's take one step back, in the new SDK version, instead of USB configfs, can you get g_ether module working in the same way as the old SDK version?

Hi Bin Liu,

I am currently using kernel version 5.10.168. I have managed to get the g_ether module working as it did in the old SDK version. However, I am encountering issues with the new ConfigFS interface. Specifically, I see the following error in dmesg when attempting to bind the UDC:

[ 62.292675] USB_ADD_FUNCTION:ret:-19

[ 62.308068] udc 31000000.usb: failed to start g1: -19

Would you have any insights on how to resolve this issue with ConfigFS

Thanks,

Laxman

Hi Laxman,

Instead of your USB configfs script, can you please test with the script attached below to see if you can create the USB gadget with just a single functions - serial?

#!/bin/bash
# $1: -d - tear down

#FUNCS=("mass_storage.usb0")
#FUNCS=("hid.usb0")
#FUNCS=("uvc.usb0")
#FUNCS=("uac1.usb0")
#FUNCS=("uac2.usb0")
#FUNCS=("SourceSink.usb0")
#FUNCS=("uvc.usb0" "hid.usb0")
#FUNCS=("acm.usb0" "ncm.usb0" "acm.usb1")

#FUNCS=("uac1.usb0" "hid.usb0")
#FUNCS=("uac2.usb0" "hid.usb0")
#FUNCS=("acm.usb0" "acm.usb1")
#FUNCS=("ecm.usb0" "rndis.usb0")
FUNCS=("acm.usb0")

CFS=/sys/kernel/config/usb_gadget
VID="0x1d6d"
PID="0x0104"
LANG="0x409"
GNAME=g1

RNDIS_DEV_ADDR="12:22:33:44:55:66"
RNDIS_HOST_ADDR="12:22:33:44:55:65"
ECM_DEV_ADDR="12:22:33:44:55:68"
ECM_HOST_ADDR="12:22:33:44:55:67"

hid_report="\\x05\\x01\\x09\\x06\\xa1\\x01\\x05\\x07\\x19\\xe0\\x29\\xe7\\x15\\x00\\x25\\x01\\x75\\x01\\x95\\x08\\x81\\x02\\x95\\x01\\x75\\x08\\x81\\x03\\x95\\x05\\x75\\x01\\x05\\x08\\x19\\x01\\x29\\x05\\x91\\x02\\x95\\x01\\x75\\x03\\x91\\x03\\x95\\x06\\x75\\x08\\x15\\x00\\x25\\x65\\x05\\x07\\x19\\x00\\x29\\x65\\x81\\x00\\xc0"



init()
{
	zcat /proc/config.gz | grep 'CONFIGFS_FS=' > /dev/null || exit 1
	lsmod | grep libcomposite > /dev/null || modprobe libcomposite || exit 2
	mount | grep configfs > /devnull || 
		mount -t configfs none $(dirname $CFS) || exit 3
}

create_gadget()
{
	[ ! -d ${CFS}/${GNAME} ] || exit 5
	mkdir ${CFS}/${GNAME} && cd ${CFS}/${GNAME} || exit 6
	echo "$VID" > idVendor
	echo "$PID" > idProduct

	mkdir strings/$LANG
	echo "0123456789" > strings/$LANG/serialnumber
	echo "Foo Inc" > strings/$LANG/manufacturer
	echo "Bar gadget" > strings/$LANG/product
}

# configuraton naming: configs/<name>.<number>
create_config()
{
	[ -d ${CFS}/${GNAME} ] && cd ${CFS}/${GNAME} || exit 5
	mkdir configs/c.1
	mkdir configs/c.1/strings/$LANG
	echo "conf1" > configs/c.1/strings/$LANG/configuration
}

# $1 - function name
# function naming: functions/<name>.<instance_name>
create_func_single()
{
	local _func=$1

	mkdir functions/${_func} || return
	case $_func in
	"mass_storage."*)
		local _msc=/dev/shm/gmsc-${_func#*.}.file

 		[ -f $_msc ] || dd if=/dev/zero of=$_msc bs=1M count=32
		echo $_msc > functions/${_func}/lun.0/file
		;;
	"hid."*)
		echo 1 > functions/${_func}/protocol
		echo 1 > functions/${_func}/subclass
		echo 8 > functions/${_func}/report_length
		echo -ne $hid_report > functions/${_func}/report_desc
		;;
	"uvc."*)
		mkdir functions/${_func}/control/header/h
		cd functions/${_func}/control
		ln -s header/h class/fs
		ln -s header/h class/ss
		cd ${CFS}/${GNAME}

		_w=640
		_h=360
		_fps=30

		mkdir -p functions/${_func}/streaming/uncompressed/u/${_h}p
		cd functions/${_func}/streaming/uncompressed/u/${_h}p
		echo $_w > wWidth
		echo $_h > wHeight
		echo $((_h * _w * 2 * _fps)) > dwMaxBitRate
		echo $((_h * _w * 2 * _fps)) > dwMinBitRate
		echo $((_h * _w * 2)) > dwMaxVideoFrameBufferSize
		echo 333333 > dwFrameInterval
		echo 333333 > dwDefaultFrameInterval
#666666
#1000000
#5000000
		cd ${CFS}/${GNAME}
		mkdir functions/${_func}/streaming/header/h
		cd functions/${_func}/streaming/header/h
		ln -s ../../uncompressed/u
		cd ../../class/fs
		ln -s ../../header/h
		cd ../../class/hs
		ln -s ../../header/h
		cd ../../class/ss
		ln -s ../../header/h
		cd ${CFS}/g1

		echo 1024 > functions/${_func}/streaming_maxpacket
		;;
	"rndis."*)
#		echo $RNDIS_HOST_ADDR > functions/${_func}/host_addr
#		echo $RNDIS_DEV_ADDR > functions/${_func}/dev_addr

		# match MS built-in RNDIS driver
		echo EF > functions/${_func}/class
		echo 04 > functions/${_func}/subclass
		echo 01 > functions/${_func}/protocol
		;;
	"ecm."*)
#		echo $ECM_HOST_ADDR > functions/${_func}/host_addr
#		echo $ECM_DEV_ADDR > functions/${_func}/dev_addr
		;;
	esac
	ln -s functions/${_func} configs/c.1
}

activate()
{
	local _udc

	_udc=$(ls /sys/class/udc/)
	# TODO check $_udc
#	case $port in
#	"1") _udc=48890000.usb ;;
#	"2") _udc=488d0000.usb;;
#	esac
	echo _ $_udc _
	echo "$_udc" > UDC
}

teardown()
{
	# TODO: test hid & uvc
	local _ent

	[ -d ${CFS}/${GNAME} ] && cd ${CFS}/${GNAME} || exit 5
	echo "" > UDC
	for _ent in $(ls configs/c.1/); do
		[[ "$_ent" != "MaxPower" ]] || continue
		[[ "$_ent" != "bmAttributes" ]] || continue
		[[ "$_ent" != "strings" ]] || continue
		
		rm -f configs/c.1/$_ent
	done

	for _ent in $(ls functions/); do
		case $_ent in
		"uvc."*)
			rm -rf functions/$_ent/streaming 2>/dev/null
			;;
		esac

		rm -rf functions/$_ent 2>/dev/null
	done

	rmdir configs/c.1/strings/$LANG
	rmdir configs/c.1
	rmdir strings/$LANG
	cd .. && rmdir $GNAME
	echo "toredown"
}

### MAIN ###

case "$1" in
"-d") teardown; exit 0;;
#"1") port=1;;
#"2") port=2;;
#*) echo "invalid param $1."; exit 1;;
esac

init
create_gadget
create_config
for func in ${FUNCS[*]}; do
	echo "creating $func ..."
	create_func_single $func
done
activate
echo created

Hi Bin Lu,

I am writing to inform you that the USB gadget configuration script executed successfully. Below are the details of the execution and the current status of the USB gadget.

creating acm.usb0 ...
[ 56.079965] registering udc driver.
[ 56.083542] configfs_composite bind funtion
[ 56.091627] composite dev prepare ret:0
[ 56.095893] Attempting to add function: acm
[ 56.100854] USB_ADD_FUNCTION:ret:0
[ 56.104575] Successfully added function: acm
[ 56.114746] udc driver binding ret:0
created

# dmesg | grep -i usb
[ 56.100854] USB_ADD_FUNCTION:ret:0

# ls /sys/kernel/config/usb_gadget/g1/
UDC bMaxPacketSize0 functions os_desc
bDeviceClass bcdDevice idProduct strings
bDeviceProtocol bcdUSB idVendor
bDeviceSubClass configs max_speed

# cat /sys/kernel/config/usb_gadget/g1/UDC
31000000.usb
#

The above results indicate that the USB gadget was created successfully and the UDC is bound to the device 31000000.usb.

Please let me know if further information or actions are required.

Best regards,

Laxman B

Okay, now if you connect the AM62x USB0 port to PC USB port, does the PC detect it as a serial port?

Yes, its showing COM17 Usb Serial Device

Okay, it means you don't have USB hardware or Linux problems on your board. The issue is likely in your USB configfs script.

Please compare your script with mine, from the single serial function, gradually adding new feature/function, and debug to see where in your script causes the problem.