USB

USB interface usage

Connecting USB Devices

Insert the USB device (such as USB flash drive, mouse, keyboard, etc.) into the USB port of the development board. The system will automatically identify the device and load the corresponding driver.

View connected USB devices

Use the following command to view currently connected USB devices:

root@linaro-alip:/# lsusb
Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 002: ID 046d:c077 Logitech, Inc. Mouse
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

As shown above, you can see that the mouse has been recognized

Mounting USB storage device

If a USB storage device (such as a USB flash drive) is connected, you can mount it by following the steps below:

1. View the device node:

root@linaro-alip:/# fdisk -l
...
Device     Boot Start       End   Sectors  Size Id Type
/dev/sda1        2048 122879966 122877919 58.6G  c W95 FAT32 (LBA)

2. Create a mount point and mount the device:

mkdir /mnt/usb
mount /dev/sda1 /mnt/usb

3. View the mounting results:

root@linaro-alip:/# df -h
Filesystem      Size  Used Avail Use% Mounted on
...
/dev/sda1        59G  768K   59G   1% /mnt/usb

4. Uninstall the device:

umount /mnt/usb

Using USB OTG function

The USB 3.0 OTG interface of RK3568 supports device mode (such as USB disk mode) and host mode.

Device Mode

Configure OTG as device mode:

echo peripheral > /sys/devices/platform/fe8a0000.usb2-phy/otg_mode

Connect the development board to the PC, and the PC will recognize the development board as a USB device.

Host Mode

Configure OTG as host mode:

echo host > /sys/devices/platform/fe8a0000.usb2-phy/otg_mode

Connect the USB device to the OTG port, and the development board will recognize the USB device.

USB transfer rate

1. Confirm the USB storage device through lsblk to confirm the USB storage device

root@linaro-alip:/# lsblk
NAME         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda            8:0    1 58.6G  0 disk
mmcblk0      179:0    0 28.9G  0 disk
├─mmcblk0p1  179:1    0    4M  0 part
├─mmcblk0p2  179:2    0    4M  0 part
├─mmcblk0p3  179:3    0   64M  0 part
├─mmcblk0p4  179:4    0  128M  0 part
├─mmcblk0p5  179:5    0   32M  0 part
├─mmcblk0p6  179:6    0    6G  0 part /
├─mmcblk0p7  179:7    0  128M  0 part /oem
└─mmcblk0p8  179:8    0 22.5G  0 part /userdata
mmcblk0boot0 179:32   0    4M  1 disk
mmcblk0boot1 179:64   0    4M  1 disk
zram0        254:0    0    0B  0 disk

As shown above, the USB storage device inserted into ROCK 3B is /dev/sda

1. Reading test

root@linaro-alip:/# sudo dd if=/dev/sda of=/dev/null bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 3.34566 s, 31.3 MB/s

This command will read data from the USB device and write it to /dev/null to test the read speed. Here, the block size to be written is specified as 1M, and 100 blocks are specified to be read, so a total of 100 MB of data is read, and the read speed is 31.3 MB/s

1. Write test

root@linaro-alip:/# sudo dd if=/dev/zero of=/dev/sda bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 6.96282 s, 15.1 MB/s

Here, the size of the block to be written is specified as 1M, 100 blocks are written, a total of 100M of data is written, and the write speed is 15.1 MB/s