> ## Documentation Index > Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt > Use this file to discover all available pages before exploring further. # USB The Universal Serial Bus (USB) supports data exchange and power supply between electronic devices at speeds from 1.5 Mbps (low speed) up to 10 Gbps (SuperSpeed Plus). The IQ-9075 uses the **Synopsys DesignWare Core SuperSpeed USB 3.x** controller connected to USB2 PHY (UTMI) and USB3 PHY (PIPE) interfaces. The board features three USB connectors: two Type-C (USB0, USB1) and one micro-USB (USB2). ## Controllers | Controller | Address | Max Speed | HS PHY Rails | SS PHY Rails | | ---------- | --------- | ------------------ | -------------------------------------------- | ------------ | | **USB0** | 0xa600000 | USB 3.x SuperSpeed | L7A (0.88V), L6C (1.8V), L9A (3.3V) | L1C, L7A | | **USB1** | 0xa800000 | USB 3.x SuperSpeed | L7A (0.88V), L6C (1.8V), L9A (3.3V) | L1C, L7A | | **USB2** | 0xa400000 | USB 2.0 High Speed | VDD\_A\_USBHS\_2\_1P8, VDD\_A\_USBHS\_2\_3P1 | — | ## Features ### Hardware Features | Feature | Description | | -------------------------- | ------------------------------------------------- | | **Dual-Role Device (DRD)** | Host and device modes with dynamic role detection | | **USB 3.1 Gen1** | SuperSpeed 5 Gbps on USB0 and USB1 | | **USB 2.0 High Speed** | 480 Mbps on all controllers | | **xHCI** | eXtensible Host Controller Interface compliance | | **Transfer types** | Control, bulk, interrupt, isochronous | | **Link Power Management** | ASPM-style LPM for power savings | ### Software Features **Peripheral mode:** Mass Storage, Diagnostics (FunctionFS), RNDIS, NCM **Host mode:** xHCI, HID/MS/Hub class drivers, UVC (USB camera), Link Power Management ## Architecture | Layer | Key Components | | -------------- | -------------------------------------------------------------------- | | **User Space** | `diag-router`, `qusb` — service management, composition switching | | **VFS** | `/dev/ffs-*`, `/sys/kernel/config` — dynamic config, endpoint access | | **Kernel** | `dwc3-qcom`, xHCI, Gadget Framework — dual-role, power management | | **Hardware** | DWC3 Controllers, Femto/QMP PHYs | ## Configuration ### Runtime Power Management ```bash theme={null} # Enable autosuspend echo auto > /sys/bus/platform/devices/a600000.usb/power/control echo 2000 > /sys/bus/platform/devices/a600000.usb/power/autosuspend_delay_ms # Check status cat /sys/bus/platform/devices/a600000.usb/power/runtime_status ``` Runtime PM is not supported for Type-C ports on IQ-9075. ### Enable Remote Wake-up (Host Mode) ```bash theme={null} # Enable wake-up for xHCI echo enabled > /sys/bus/platform/devices/xhci-hcd.X.auto/power/wakeup # Enable wake-up for root hubs echo enabled > /sys/bus/usb/devices/usb1/power/wakeup echo enabled > /sys/bus/usb/devices/usb2/power/wakeup ``` ### Prevent Suspend During Composition Switch ```bash theme={null} echo on > /sys/bus/platform/devices/a600000.usb/power/control # Perform composition switch echo auto > /sys/bus/platform/devices/a600000.usb/power/control ``` ## USB Camera The IQ-9075 supports USB cameras that comply with the USB Video Class (UVC) standard via the `uvcvideo` kernel driver, exposing devices as `/dev/videoX`. ### Detect and Configure ```bash theme={null} lsusb v4l2-ctl --list-devices ls -l /dev/v4l/by-id/ ``` ```bash theme={null} yavta /dev/video2 --enum-formats ``` ```bash theme={null} # MJPEG capture yavta -f MJPEG -s 1280x720 -t 1/30 -c10 -F/home/ubuntu/test.jpeg /dev/video2 # YUYV capture yavta -f YUYV -s 1280x720 -t 1/5 -c10 -F/tmp/test.yuv /dev/video2 ``` ```bash theme={null} ffplay -f v4l2 -framerate 30 -input_format mjpeg -video_size 1920x1080 -i /dev/video2 ffplay -f v4l2 -framerate 30 -input_format yuyv422 -video_size 1920x1080 -i /dev/video2 ``` ```bash theme={null} export XDG_RUNTIME_DIR=/run/user/$(id -u ubuntu) export WAYLAND_DISPLAY=wayland-1 # 720p stream (YUYV = YUY2 in GStreamer) gst-launch-1.0 -e v4l2src device=/dev/video2 ! \ video/x-raw,format=YUY2,width=1280,height=720,framerate=30/1 ! \ videoconvert ! waylandsink fullscreen=true ``` For multi-stream inference with USB cameras, see the [Qualcomm IM SDK](../../../ai-workflows/im-sdk) and the [gst-usb-single-camera-app](https://docs.qualcomm.com/doc/80-70022-50/topic/usb-camera.html). ## Verification ### Host Mode ```bash theme={null} lsusb # List connected USB devices cat /sys/kernel/debug/usb/devices # Detailed device info ls /sys/bus/usb/devices/ # USB device tree ``` ### Device Mode ```bash theme={null} cat /sys/kernel/debug/usb/a600000.usb/mode # Check USB mode cat /sys/kernel/debug/usb/a600000.usb/link_state # Check link state qusb showpid # List compositions ``` ## Debugging ### Enable USB Tracing ```bash theme={null} mount -t debugfs none /sys/kernel/debug # Enable traces echo 1 > /sys/kernel/debug/tracing/events/dwc3/enable echo 1 > /sys/kernel/debug/tracing/events/xhci-hcd/enable echo 1 > /sys/kernel/debug/tracing/events/gadget/enable cat /sys/kernel/debug/tracing/trace ``` ### Collect Register Dumps ```bash theme={null} mkdir -p /tmp/usb_debug cat /sys/kernel/debug/usb/a600000.usb/regdump > /tmp/usb_debug/regdump.txt cat /sys/kernel/debug/usb/a600000.usb/lsp_dump > /tmp/usb_debug/lsp_dump.txt cat /sys/kernel/debug/usb/a600000.usb/mode > /tmp/usb_debug/mode.txt cat /sys/kernel/debug/usb/a600000.usb/link_state > /tmp/usb_debug/link_state.txt dmesg > /tmp/usb_debug/dmesg.txt lsusb -v > /tmp/usb_debug/lsusb.txt ``` ## Troubleshooting ```bash theme={null} cat /sys/kernel/debug/usb/a600000.usb/mode cat /sys/kernel/debug/usb/a600000.usb/link_state dmesg | grep -i usb ``` * Rebind gadget: `qusb unbind && qusb bind` * Change composition: `qusb setpid ` * Check cable connection and power rails ```bash theme={null} lsusb ls /dev/video* dmesg | grep -i uvc lsmod | grep uvcvideo ``` * Ensure `uvcvideo` driver is loaded * Try a different USB port * Verify camera is UVC-compliant ```bash theme={null} cat /sys/bus/platform/devices/a600000.usb/power/runtime_status cat /sys/bus/platform/devices/a600000.usb/power/control ``` Enable autosuspend: ```bash theme={null} echo auto > /sys/bus/platform/devices/a600000.usb/power/control echo 2000 > /sys/bus/platform/devices/a600000.usb/power/autosuspend_delay_ms ``` Prevent suspend during the switch: ```bash theme={null} echo on > /sys/bus/platform/devices/a600000.usb/power/control qusb setpid echo auto > /sys/bus/platform/devices/a600000.usb/power/control ``` ## Resources * [DWC3 QCOM Driver](https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/usb/dwc3/dwc3-qcom.c?h=v6.6.2) * [Femto PHY Driver](https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c?h=v6.6.2) * [UVC Video Driver](https://www.kernel.org/doc/html/v4.19/media/v4l-drivers/uvcvideo.html) * [LibUVC](https://github.com/libuvc/libuvc)