USB

通用串行总线 (USB) 是一种行业标准，允许在各种类型的电子设备之间进行数据交换和供电。该标准支持多种运行速度，例如 1.5 Mbps 低速、12 Mbps 全速、480 Mbps 高速以及 5 Gbps 超高速和 10 Gbps 超高速 Plus。

魔方派 3 拥有 4 个 USB 口：

两个 USB 3.0 A 口，只能作为主机模式使用，如下图 7。
一个 USB 2.0 A 口，可以作为主机或设备模式使用，如下图 6。
一个 USB 3.1 Gen 1 C 口，可以作为主机或设备模式（常用于 ADB），以及 DP 显示使用，如下图 5。

备注

在 Ubuntu 24.04 V1.0.0 版本中暂不支持 DP 功能。该功能支持将在未来的版本中提供。

USB 接口功能验证

USB 摄像头

魔方派 3 设备为符合 USB 视频类（UVC）标准的 USB 网络摄像头提供驱动程序支持。Linux 内核的 uvcvideo 驱动程序支持摄像头。有关 uvcvideo 驱动程序的更多信息，请参阅 https://www.kernel.org/doc/html/v4.19/media/v4l-drivers/uvcvideo.html

uvcvideo 驱动程序将这类摄像头作为 V4L2 视频设备（可通过字符设备节点（如 /dev/videoX）进行访问）公开。

在用户空间中，应用程序可以使用 v4l2src GStreamer 插件管理 USB 摄像头，该插件与 Qualcomm 智能多媒体 SDK (QIM SDK) 捆绑在一起。此外，Yavta（另一个 V4L2 测试应用程序）等程序可以直接与 V4L2（Video4Linux2）接口交互，对摄像头设备进行测试和控制。

安装 Yavta

sudo apt install yavta

前提条件：获取图像格式大小

要通过 Yavta 或 GStreamer 配置 USB 摄像头，必须执行以下步骤。

要了解枚举详细信息，应连接 USB 摄像头并运行以下命令。

lsusb

随即显示以下输出。

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 1bcf:0215 Sunplus Innovation Technology Inc. 4K AutoFocus Webcam
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 002: ID 0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

USB 摄像头插入前后，在魔方派 3 的终端，执行如下命令，根据两次结果的差异可以确定 USB 摄像头视频节点。

ls /dev/video*

示例输出：

root@rubikpi:/sys/bus/pci# ls /dev/video*
/dev/video0  /dev/video1  /dev/video32  /dev/video33
root@rubikpi:/sys/bus/pci# ls /dev/video*
/dev/video0  /dev/video1  /dev/video2  /dev/video3  /dev/video32  /dev/video33

如上所示，USB 摄像头的节点为 video2 和 video3。

要使用 Yavta 查看支持的输出格式和大小，应运行以下命令：

yavta /dev/video2 --enum-formats

随即显示以下输出。

Device /dev/video3 opened.
Device `4K AutoFocus Webcam: 4K AutoFoc' on `usb-0000:01:00.0-1' (driver 'uvcvideo') supports meta-d.
- Available formats:
        Format 0: UVCH (48435655)
        Type: Meta-data capture (13)
        Name: UVC Payload Header Metadata

Meta-data format: UVCH (48435655) buffer size 10240
ubuntu@rubikpi:~$ yavta /dev/video2 --enum-formats
Device /dev/video2 opened.
Device `4K AutoFocus Webcam: 4K AutoFoc' on `usb-0000:01:00.0-1' (driver 'uvcvideo') supports video,.
- Available formats:
        Format 0: MJPEG (47504a4d)
        Type: Video capture (1)
        Name: Motion-JPEG
        Frame size: 1920x1080 (1/30, 1/30)
        Frame size: 1280x720 (1/30)
        Frame size: 1600x900 (1/30)
        Frame size: 2304x1296 (1/30)
        Frame size: 2560x1440 (1/30)
        Frame size: 2688x1512 (1/30)
        Frame size: 3840x2160 (1/25)
        Frame size: 640x360 (1/30)
        Frame size: 800x450 (1/30)
        Frame size: 848x480 (1/30)
        Frame size: 960x540 (1/30)
        Frame size: 1024x576 (1/30)
        Frame size: 640x480 (1/30)
        Frame size: 800x600 (1/30)
        Frame size: 960x720 (1/30)
        Frame size: 1024x768 (1/30)
        Frame size: 1280x960 (1/30)
        Frame size: 1600x1200 (1/30)
        Frame size: 2048x1536 (1/30)
        Frame size: 2592x1944 (1/30)
        Frame size: 1920x1080 (1/30, 1/30)

        Format 1: YUYV (56595559)
        Type: Video capture (1)
        Name: YUYV 4:2:2
        Frame size: 1920x1080 (1/5, 1/5)
        Frame size: 1280x720 (1/10)
        Frame size: 1600x900 (1/5)
        Frame size: 640x360 (1/30)
        Frame size: 800x450 (1/20)
        Frame size: 848x480 (1/20)
        Frame size: 960x540 (1/20)
        Frame size: 1024x576 (1/15)
        Frame size: 640x480 (1/30)
        Frame size: 800x600 (1/20)
        Frame size: 960x720 (1/15)
        Frame size: 1024x768 (1/10)
        Frame size: 1280x960 (2/15)
        Frame size: 1600x1200 (1/5)
        Frame size: 1920x1080 (1/5, 1/5)

Video format: MJPEG (47504a4d) 1920x1080 (stride 0) field none buffer size 4147200

从第 3 步的显示结果中选择所需的图像格式和大小。

使用 Yavta 配置 USB 摄像头

前提条件：USB 摄像头输出格式和大小已确定。

请运行以下命令，以便选择 1920x1080 输出尺寸和 30 fps 的 MJPEG 格式，在 /tmp/ 下采集 10 帧，文件名为 testmjpeg-00000*.bin。

yavta -f MJPEG -s 1920x1080 -t 1/30 -c10 -F/tmp/testmjpeg /dev/video2

随即显示以下输出。

Device /dev/video2 opened.
Device `4K AutoFocus Webcam: 4K AutoFoc' on `usb-0000:01:00.0-1' (driver 'uvcvideo') supports video, capture, without mplanes.
Video format set: MJPEG (47504a4d) 1920x1080 (stride 0) field none buffer size 4147200
Video format: MJPEG (47504a4d) 1920x1080 (stride 0) field none buffer size 4147200
Current frame rate: 1/30
Setting frame rate to: 1/30
Frame rate set: 1/30
8 buffers requested.
length: 4147200 offset: 0 timestamp type/source: mono/SoE
Buffer 0/0 mapped at address 0xffffa5e5b000.
length: 4147200 offset: 32768 timestamp type/source: mono/SoE
Buffer 1/0 mapped at address 0xffffa5a66000.
length: 4147200 offset: 65536 timestamp type/source: mono/SoE
Buffer 2/0 mapped at address 0xffffa5671000.
length: 4147200 offset: 98304 timestamp type/source: mono/SoE
Buffer 3/0 mapped at address 0xffffa527c000.
length: 4147200 offset: 131072 timestamp type/source: mono/SoE
Buffer 4/0 mapped at address 0xffffa4e87000.
length: 4147200 offset: 163840 timestamp type/source: mono/SoE
Buffer 5/0 mapped at address 0xffffa4a92000.
length: 4147200 offset: 196608 timestamp type/source: mono/SoE
Buffer 6/0 mapped at address 0xffffa469d000.
length: 4147200 offset: 229376 timestamp type/source: mono/SoE
Buffer 7/0 mapped at address 0xffffa42a8000.
0 (0) [-] none 0 115283 B 53.095060 53.647782 244.260 fps ts mono/SoE
1 (1) [-] none 1 115277 B 53.647091 53.679768 1.811 fps ts mono/SoE
2 (2) [-] none 2 115376 B 53.683085 53.715810 27.782 fps ts mono/SoE
3 (3) [-] none 3 115545 B 53.715105 53.747738 31.230 fps ts mono/SoE
4 (4) [-] none 4 117998 B 53.747096 53.783769 31.259 fps ts mono/SoE
5 (5) [-] none 5 117962 B 53.783089 53.815715 27.783 fps ts mono/SoE
6 (6) [-] none 6 118127 B 53.815088 53.847740 31.251 fps ts mono/SoE
7 (7) [-] none 7 118027 B 53.847099 53.883764 31.239 fps ts mono/SoE
8 (0) [-] none 8 119080 B 53.883084 53.915721 27.789 fps ts mono/SoE
9 (1) [-] none 9 119399 B 53.915093 53.947736 31.241 fps ts mono/SoE
Captured 10 frames in 0.856770 seconds (11.671741 fps, 1368014.420968 B/s).
8 buffers released.

请运行以下命令，以便选择 1280x720 输出尺寸、15 fps 的 YUV 格式，在 /tmp/ 下采集 10 帧，生成的文件名为 testyuv-00000*.bin。

yavta -f YUYV -s 1280x720 -t 1/15 -c10 -F/tmp/testyuv /dev/video2

随即显示以下输出。

Device /dev/video2 opened.
Device `4K AutoFocus Webcam: 4K AutoFoc' on `usb-0000:01:00.0-1' (driver 'uvcvideo') supports video,.
Video format set: YUYV (56595559) 1280x720 (stride 2560) field none buffer size 1843200
Video format: YUYV (56595559) 1280x720 (stride 2560) field none buffer size 1843200
Current frame rate: 1/10
Setting frame rate to: 1/15
Frame rate set: 1/10
8 buffers requested.
length: 1843200 offset: 0 timestamp type/source: mono/SoE
Buffer 0/0 mapped at address 0xffff966ce000.
length: 1843200 offset: 32768 timestamp type/source: mono/SoE
Buffer 1/0 mapped at address 0xffff9650c000.
length: 1843200 offset: 65536 timestamp type/source: mono/SoE
Buffer 2/0 mapped at address 0xffff9634a000.
length: 1843200 offset: 98304 timestamp type/source: mono/SoE
Buffer 3/0 mapped at address 0xffff96188000.
length: 1843200 offset: 131072 timestamp type/source: mono/SoE
Buffer 4/0 mapped at address 0xffff95fc6000.
length: 1843200 offset: 163840 timestamp type/source: mono/SoE
Buffer 5/0 mapped at address 0xffff95e04000.
length: 1843200 offset: 196608 timestamp type/source: mono/SoE
Buffer 6/0 mapped at address 0xffff95c42000.
length: 1843200 offset: 229376 timestamp type/source: mono/SoE
Buffer 7/0 mapped at address 0xffff95a80000.
0 (0) [-] none 0 1843200 B 364.737849 364.966754 2.174 fps ts mono/SoE
1 (1) [-] none 1 1843200 B 364.966042 365.066785 4.382 fps ts mono/SoE
2 (2) [-] none 2 1843200 B 365.066087 365.166812 9.996 fps ts mono/SoE
3 (3) [-] none 3 1843200 B 365.166149 365.266862 9.994 fps ts mono/SoE
4 (4) [-] none 4 1843200 B 365.266205 365.366929 9.994 fps ts mono/SoE
5 (5) [-] none 5 1843200 B 365.366266 365.466985 9.994 fps ts mono/SoE
6 (6) [-] none 6 1843200 B 365.466326 365.567108 9.994 fps ts mono/SoE
7 (7) [-] none 7 1843200 B 365.566381 365.667099 9.995 fps ts mono/SoE
8 (0) [-] none 8 1843200 B 365.666440 365.767150 9.994 fps ts mono/SoE
9 (1) [-] none 9 1843200 B 365.766496 365.867212 9.994 fps ts mono/SoE
Captured 10 frames in 1.589346 seconds (6.291895 fps, 11597220.863435 B/s).
8 buffers released.

USB 调试

本节提供有关获取调试日志的各种方法的信息。调试方式有 regdumps 、调试 ftraces 、 configfs 节点等。在调试与进入/退出低功耗模式、SMMU 故障、无时钟访问相关的问题时，可通过上述日志查看事件和控制器状态的详细信息。

以下命令需要 root 权限。执行以下命令来获取 root 权限：

sudo su

如需退出 root 权限模式，只需输入exit 命令。

USB 2.0 Type-A 设备路径： /sys/devices/platform/soc@0/8c00000.usb/xhci-hcd.1.auto/usb3/
USB 3.0 Type-A 设备路径：
- /sys/devices/platform/soc@0/1c00000.pci/pci0000:00/0000:00:00.0/0000:01:00.0/usb1
- /sys/devices/platform/soc@0/1c00000.pci/pci0000:00/0000:00:00.0/0000:01:00.0/usb2
USB 3.1 Type-C 设备路径：/sys/devices/platform/soc@0/a600000.usb

USB 跟踪

使用 debugfs 跟踪可以更加深入地了解 USB 线上发生的每一个事务。如需查看跟踪列表，可运行以下命令。

注意

执行命令前，确保已挂载 debugfs。如果尚未挂载，可运行以下命令：

sudo mount -t debugfs none /sys/kernel/debug

ls /sys/kernel/debug/tracing/events/dwc3

以下是可用于验证 xHCI/gadget 协议栈/USB Type-C 连接器系统软件接口 (UCSI) 中的数据传输的跟踪。

dwc3_alloc_request  dwc3_event              dwc3_gadget_generic_cmd  enable
dwc3_complete_trb   dwc3_free_request       dwc3_gadget_giveback     filter
dwc3_ctrl_req       dwc3_gadget_ep_cmd      dwc3_prepare_trb
dwc3_ep_dequeue     dwc3_gadget_ep_disable  dwc3_readl
dwc3_ep_queue       dwc3_gadget_ep_enable   dwc3_writel

要列出 xHCI/主机控制器驱动程序 (HCD) 中的跟踪数据，请运行以下命令。

ls /sys/kernel/debug/tracing/events/xhci-hcd

以下是可用于验证 xHCI/HCD 中数据传输的跟踪。

enable                            xhci_handle_cmd_config_ep
filter                            xhci_handle_cmd_disable_slot
  xhci_add_endpoint                 xhci_handle_cmd_reset_dev
  xhci_address_ctrl_ctx             xhci_handle_cmd_reset_ep
  xhci_address_ctx                  xhci_handle_cmd_set_deq
  xhci_alloc_dev                    xhci_handle_cmd_set_deq_ep
  xhci_alloc_virt_device            xhci_handle_cmd_stop_ep
  xhci_configure_endpoint           xhci_handle_command
  xhci_configure_endpoint_ctrl_ctx  xhci_handle_event
  xhci_dbc_alloc_request            xhci_handle_port_status
  xhci_dbc_free_request             xhci_handle_transfer
  xhci_dbc_gadget_ep_queue          xhci_hub_status_data
  xhci_dbc_giveback_request         xhci_inc_deq
  xhci_dbc_handle_event             xhci_inc_enq
  xhci_dbc_handle_transfer          xhci_queue_trb
  xhci_dbc_queue_request            xhci_ring_alloc
  xhci_dbg_address                  xhci_ring_ep_doorbell
  xhci_dbg_cancel_urb               xhci_ring_expansion
  xhci_dbg_context_change           xhci_ring_free
  xhci_dbg_init                     xhci_ring_host_doorbell
  xhci_dbg_quirks                   xhci_setup_addressable_virt_device
  xhci_dbg_reset_ep                 xhci_setup_device
  xhci_dbg_ring_expansion           xhci_setup_device_slot
  xhci_discover_or_reset_device     xhci_stop_device
  xhci_free_dev                     xhci_urb_dequeue
  xhci_free_virt_device             xhci_urb_enqueue
  xhci_get_port_status              xhci_urb_giveback
  xhci_handle_cmd_addr_dev

请运行以下命令，以便列出 USB 视频类 (UVC) gadget 驱动程序的可用事件。

ls /sys/kernel/debug/tracing/events/gadget

随即显示以下输出。

enable                      usb_gadget_activate
  filter                      usb_gadget_clear_selfpowered
  usb_ep_alloc_request        usb_gadget_connect
  usb_ep_clear_halt           usb_gadget_deactivate
  usb_ep_dequeue              usb_gadget_disconnect
  usb_ep_disable              usb_gadget_frame_number
  usb_ep_enable               usb_gadget_giveback_request
  usb_ep_fifo_flush           usb_gadget_set_remote_wakeup
  usb_ep_fifo_status          usb_gadget_set_selfpowered
  usb_ep_free_request         usb_gadget_vbus_connect
  usb_ep_queue                usb_gadget_vbus_disconnect
  usb_ep_set_halt             usb_gadget_vbus_draw
  usb_ep_set_maxpacket_limit  usb_gadget_wakeup
  usb_ep_set_wedge

如需列出 UCSI 驱动程序中的可用事件，可运行以下命令。

ls /sys/kernel/debug/tracing/events/ucsi

随即显示以下输出。

enable  ucsi_connector_change  ucsi_register_port  ucsi_run_command
filter  ucsi_register_altmode  ucsi_reset_ppm

USB 寄存器打印

USB debugfs 提供以下信息，下面以 Type-C 接口为例。

工作模式（Type-C 接口）
```
cat /sys/kernel/debug/usb/a600000.usb/mode 
```
备注

USB 2.0 Type-A 的工作模式cat /sys/kernel/debug/usb/8c00000.usb/mode

示例输出：
```
device
```
设备模式下所有端点的状态和传输环形缓冲区 (TRB) 队列。

当前链路状态。

cat /sys/kernel/debug/usb/a600000.usb/link_state

示例输出

Sleep

列出处理器 (LSP) dump。

cat /sys/kernel/debug/usb/a600000.usb/lsp_dump

示例输出：

GDBGLSP[0] = 0x40000000
GDBGLSP[1] = 0x00003a80
GDBGLSP[2] = 0x38200000
GDBGLSP[3] = 0x00802000
GDBGLSP[4] = 0x126f1000
GDBGLSP[5] = 0x3a800018
GDBGLSP[6] = 0x00000a80
GDBGLSP[7] = 0xfc03f14a
GDBGLSP[8] = 0x0b803fff
GDBGLSP[9] = 0x00000000
GDBGLSP[10] = 0x000000f8
GDBGLSP[11] = 0x000000f8
GDBGLSP[12] = 0x000000f8
GDBGLSP[13] = 0x000000f8
GDBGLSP[14] = 0x000000f8
GDBGLSP[15] = 0x000000f8

ls /sys/kernel/debug/usb/a600000.usb

示例输出：

ep0in    ep11out  ep14in   ep1out  ep4in   ep6out  ep9in       regdump
ep0out   ep12in   ep14out  ep2in   ep4out  ep7in   ep9out      testmode
ep10in   ep12out  ep15in   ep2out  ep5in   ep7out  link_state
ep10out  ep13in   ep15out  ep3in   ep5out  ep8in   lsp_dump
ep11in   ep13out  ep1in    ep3out  ep6in   ep8out  mode

regdump 命令提供以下寄存器的寄存器空间的当前状态：

设备模式的寄存器，例如 DCTL、DSTS 和 DCFG
全局寄存器，例如 GCTL 和 GSTS

cd /sys/kernel/debug/usb/a600000.usb
cat regdump

示例输出：

GSBUSCFG0 = 0x2222000e
GSBUSCFG1 = 0x00001700
GTXTHRCFG = 0x00000000
GRXTHRCFG = 0x00000000
GCTL = 0x00102000
GEVTEN = 0x00000000
GSTS = 0x7e800000
GUCTL1 = 0x810c1802
GSNPSID = 0x5533330a
GGPIO = 0x00000000
GUID = 0x00060500
GUCTL = 0x0d00c010
GBUSERRADDR0 = 0x00000000
GBUSERRADDR1 = 0x00000000
GPRTBIMAP0 = 0x00000000
GPRTBIMAP1 = 0x00000000
GHWPARAMS0 = 0x4020400a
GDBGFIFOSPACE = 0x00420000
GDBGLTSSM = 0x41090658
GDBGBMU = 0x20300000
GPRTBIMAP_HS0 = 0x00000000
GPRTBIMAP_HS1 = 0x00000000
GPRTBIMAP_FS0 = 0x00000000
GPRTBIMAP_FS1 = 0x00000000
GUCTL2 = 0x0198440d
VER_NUMBER = 0x00000000
VER_TYPE = 0x00000000
GUSB2PHYCFG(0) = 0x00002400
GUSB2I2CCTL(0) = 0x00000000
GUSB2PHYACC(0) = 0x00000000
GUSB3PIPECTL(0) = 0x030e0002
GTXFIFOSIZ(0) = 0x00000042
GRXFIFOSIZ(0) = 0x00000305
GEVNTADRLO(0) = 0xfffff000
GEVNTADRHI(0) = 0x0000000f
GEVNTSIZ(0) = 0x00001000
GEVNTCOUNT(0) = 0x00000000
GHWPARAMS8 = 0x000007ea
GUCTL3 = 0x00010000
GFLADJ = 0x8c80c8a0
DCFG = 0x00cc08b4
DCTL = 0x8cf00a00
DEVTEN = 0x00000257
DSTS = 0x008a5200
DGCMDPAR = 0x00000000
DGCMD = 0x00000000
DALEPENA = 0x0000000f
DEPCMDPAR2(0) = 0x00000000
DEPCMDPAR1(0) = 0xffffe000
DEPCMDPAR0(0) = 0x0000000f
DEPCMD(0) = 0x00000006
OCFG = 0x00000000
OCTL = 0x00000000
OEVT = 0x00000000
OEVTEN = 0x00000000
OSTS = 0x00000000

主机 sysfs 查询

要查看总线详细信息，请运行以下命令。

lsusb

示例输出：

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 03f0:134a HP, Inc Optical Mouse
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

请运行以下命令，以便列出当前目录的内容。

cd /sys/bus/usb/devices/
ls

示例输出：

1-0:1.0  1-1  1-1:1.0  2-0:1.0  usb1  usb2

要查看有关 USB 设备的详细信息，请运行以下命令。

cat /sys/kernel/debug/usb/devices

示例输出：

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 1
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev= 6.05
S:  Manufacturer=Linux 6.5.0-rc4 xhci-hcd
S:  Product=xHCI Host Controller
S:  SerialNumber=xhci-hcd.0.auto
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=1.5  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs=  1
P:  Vendor=03f0 ProdID=134a Rev= 1.00
S:  Manufacturer=PixArt
S:  Product=HP USB Optical Mouse
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=01 Prot=02 Driver=usbhid
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=10ms

T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=5000 MxCh= 1
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 3.00 Cls=09(hub  ) Sub=00 Prot=03 MxPS= 9 #Cfgs=  1
P:  Vendor=1d6b ProdID=0003 Rev= 6.05
S:  Manufacturer=Linux 6.5.0-rc4 xhci-hcd
S:  Product=xHCI Host Controller
S:  SerialNumber=xhci-hcd.0.auto
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=  0mA
I:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms

USB 接口功能验证​

USB 调试​

USB 跟踪​

USB 寄存器打印​

主机 sysfs 查询​

USB 接口功能验证

USB 调试

USB 跟踪

USB 寄存器打印

主机 sysfs 查询