Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '//devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/usbmisc/hiddev0':
    KERNEL=="hiddev0"
    SUBSYSTEM=="usbmisc"
    DRIVER==""
    ATTR{SUBSYSTEM}=="usbmisc"
    ATTR{MAJOR}=="180"
    ATTR{MINOR}=="0"

  looking at parent device '//devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0':
    KERNELS=="1-2:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="usbhid"
    ATTRS{SUBSYSTEM}=="usb"
    ATTRS{DRIVER}=="usbhid"
    ATTRS{DEVTYPE}=="usb_interface"
    ATTRS{PRODUCT}=="20a0/4108/101"
    ATTRS{TYPE}=="0/0/0"
    ATTRS{INTERFACE}=="3/0/0"
    ATTRS{MODALIAS}=="usb:v20A0p4108d0101dc00dsc00dp00ic03isc00ip00in00"
    ATTRS{USEC_INITIALIZED}=="29659295158"
    ATTRS{ID_VENDOR_FROM_DATABASE}=="Clay Logic"

  looking at parent device '//devices/pci0000:00/0000:00:14.0/usb1/1-2':
    KERNELS=="1-2"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{SUBSYSTEM}=="usb"
    ATTRS{DRIVER}=="usb"
    ATTRS{DEVTYPE}=="usb_device"
    ATTRS{PRODUCT}=="20a0/4108/101"
    ATTRS{TYPE}=="0/0/0"
    ATTRS{BUSNUM}=="001"
    ATTRS{DEVNUM}=="011"
    ATTRS{MAJOR}=="189"
    ATTRS{MINOR}=="10"
    ATTRS{USEC_INITIALIZED}=="29659287514"
    ATTRS{ID_VENDOR}=="Nitrokey"
    ATTRS{ID_VENDOR_ENC}=="Nitrokey"
    ATTRS{ID_VENDOR_ID}=="20a0"
    ATTRS{ID_MODEL}=="Nitrokey_Pro"
    ATTRS{ID_MODEL_ENC}=="Nitrokey\x20Pro"
    ATTRS{ID_MODEL_ID}=="4108"
    ATTRS{ID_REVISION}=="0101"
    ATTRS{ID_SERIAL}=="Nitrokey_Nitrokey_Pro_000000000000000000006B87"
    ATTRS{ID_SERIAL_SHORT}=="000000000000000000006B87"
    ATTRS{ID_BUS}=="usb"
    ATTRS{ID_USB_INTERFACES}==":030000:0b0000:"
    ATTRS{ID_VENDOR_FROM_DATABASE}=="Clay Logic"

  looking at parent device '//devices/pci0000:00/0000:00:14.0/usb1':
    KERNELS=="usb1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{SUBSYSTEM}=="usb"
    ATTRS{DRIVER}=="usb"
    ATTRS{DEVTYPE}=="usb_device"
    ATTRS{PRODUCT}=="1d6b/2/419"
    ATTRS{TYPE}=="9/0/1"
    ATTRS{BUSNUM}=="001"
    ATTRS{DEVNUM}=="001"
    ATTRS{MAJOR}=="189"
    ATTRS{MINOR}=="0"
    ATTRS{USEC_INITIALIZED}=="10210055"
    ATTRS{ID_VENDOR}=="Linux_4.19.0-4-amd64_xhci-hcd"
    ATTRS{ID_VENDOR_ENC}=="Linux\x204.19.0-4-amd64\x20xhci-hcd"
    ATTRS{ID_VENDOR_ID}=="1d6b"
    ATTRS{ID_MODEL}=="xHCI_Host_Controller"
    ATTRS{ID_MODEL_ENC}=="xHCI\x20Host\x20Controller"
    ATTRS{ID_MODEL_ID}=="0002"
    ATTRS{ID_REVISION}=="0419"
    ATTRS{ID_SERIAL}=="Linux_4.19.0-4-amd64_xhci-hcd_xHCI_Host_Controller_0000:00:14.0"
    ATTRS{ID_SERIAL_SHORT}=="0000:00:14.0"
    ATTRS{ID_BUS}=="usb"
    ATTRS{ID_USB_INTERFACES}==":090000:"
    ATTRS{ID_VENDOR_FROM_DATABASE}=="Linux Foundation"
    ATTRS{ID_MODEL_FROM_DATABASE}=="2.0 root hub"
    ATTRS{ID_PATH}=="pci-0000:00:14.0"
    ATTRS{ID_PATH_TAG}=="pci-0000_00_14_0"
    ATTRS{ID_FOR_SEAT}=="usb-pci-0000_00_14_0"
    ATTRS{TAGS}==":seat:"

  looking at parent device '//devices/pci0000:00/0000:00:14.0':
    KERNELS=="0000:00:14.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="xhci_hcd"
    ATTRS{SUBSYSTEM}=="pci"
    ATTRS{DRIVER}=="xhci_hcd"
    ATTRS{PCI_CLASS}=="C0330"
    ATTRS{PCI_ID}=="8086:9D2F"
    ATTRS{PCI_SUBSYS_ID}=="0000:0000"
    ATTRS{PCI_SLOT_NAME}=="0000:00:14.0"
    ATTRS{MODALIAS}=="pci:v00008086d00009D2Fsv00000000sd00000000bc0Csc03i30"
    ATTRS{USEC_INITIALIZED}=="56102608"
    ATTRS{ID_PCI_CLASS_FROM_DATABASE}=="Serial bus controller"
    ATTRS{ID_PCI_SUBCLASS_FROM_DATABASE}=="USB controller"
    ATTRS{ID_PCI_INTERFACE_FROM_DATABASE}=="XHCI"
    ATTRS{ID_VENDOR_FROM_DATABASE}=="Intel Corporation"
    ATTRS{ID_MODEL_FROM_DATABASE}=="Sunrise Point-LP USB 3.0 xHCI Controller"

  looking at parent device '//devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""