Linux中如何查看usb设备信息

目录一、cat设备节点获取信息1、usb设备在总线上的信息2、特定设备的详细信息二、使用debugfs1、挂载 debugfs 到 /sys/kernel/debug 路径下2、执行上述步骤之后3、cat 设备节点总结

下面的信息都是在VMware中运行Ubuntu12-04系统上执行的。

同样该命令也支持在嵌入式系统中进行USB调试。

一、cat设备节点获取信息

在一些嵌入式开发中需要调试USB功能，经常会cat /sys 下的相关设备节点来查看某些信息，比如说我们可以看到 /sys/bus/usb/devices 目录有多个子目录。

进入到某个子目录可以看到usb设备更加详细的信息(可以理解为设备描述符)。

1、usb设备在总线上的信息// usb设备在总线上的信息root@ubuntu:/sys/kernel/debug# cd /sys/bus/usb/devicesroot@ubuntu:/sys/bus/usb/devices# lltotal 0drwxr-xr-x 2 root root 0 Nov 26 21:21 ./drwxr-xr-x 4 root root 0 Nov 26 21:21 ../lrwxrwxrwx 1 root root 0 Nov 26 21:21 1-0:1.0 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb1/1-0:1.0/lrwxrwxrwx 1 root root 0 Dec 15 23:10 1-1 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb1/1-1/lrwxrwxrwx 1 root root 0 Dec 15 23:18 1-1:1.0 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb1/1-1/1-1:1.0/lrwxrwxrwx 1 root root 0 Nov 26 21:21 2-0:1.0 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-0:1.0/lrwxrwxrwx 1 root root 0 Nov 26 21:21 2-1 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-1/lrwxrwxrwx 1 root root 0 Nov 26 21:21 2-1:1.0 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-1/2-1:1.0/lrwxrwxrwx 1 root root 0 Nov 26 21:21 2-2 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-2/lrwxrwxrwx 1 root root 0 Nov 26 21:21 2-2:1.0 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/2-2/2-2:1.0/lrwxrwxrwx 1 root root 0 Nov 26 21:21 usb1 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:03.0/usb1/lrwxrwxrwx 1 root root 0 Nov 26 21:21 usb2 -> ../../../devices/pci0000:00/0000:00:11.0/0000:02:00.0/usb2/

其中 usbx/第x个总线，x-y:a.b/的目录格式，x表示总线号，y表示端口，a表示配置，b表示接口。

具体解释可以参照如下：

The names that begin with 'usb' refer to USB controllers. More accurately, they refer to the 'root hub' associated with each controller. The number is the USB bus number. In the example there is only one controller, so its bus is number 1. Hence the name 'usb1'.'1-0:1.0' is a special case. It refers to the root hub's interface. This acts just like the interface in an actual hub an almost every respect; see below.All the other entries refer to genuine USB devices and their interfaces. The devices are named by a scheme like this: bus-port.port.port ...In other words, the name starts with the bus number followed by a '-'. Then comes the sequence of port numbers for each of the intermediate hubs along the path to the device.For example, '1-1' is a device plugged into bus 1, port 1. It happens to be a hub, and '1-1.3' is the device plugged into port 3 of that hub. That device is another hub, and '1-1.3.1' is the device plugged into its port 1.The interfaces are indicated by suffixes having this form: :config.interfaceThat is, a ':' followed by the configuration number followed by '.' followed by the interface number. In the above example, each of the devices is using configuration 1 and this configuration has only a single interface, number 0. So the interfaces show up as; 1-1:1.0 1-1.3:1.0 1-1.3.1:1.0A hub will never have more than a single interface; that's part of the USB spec. But other devices can and do have multiple interfaces (and sometimes multiple configurations). Each interface gets its own entry in sysfs and can have its own driver.2、特定设备的详细信息

进入到某个目录中去，可以看到该设备的详细信息，可用cat命令获取信息。

// usb设备的详细信息root@ubuntu:/sys/bus/usb/devices/usb1# lltotal 0drwxr-xr-x 6 root root 0 Nov 26 21:21 ./drwxr-xr-x 4 root root 0 Nov 26 21:21 ../drwxr-xr-x 10 root root 0 Nov 26 21:21 1-0:1.0/drwxr-xr-x 5 root root 0 Dec 15 23:10 1-1/-rw-r--r-- 1 root root 4096 Dec 15 23:40 authorized-rw-r--r-- 1 root root 4096 Dec 15 23:40 authorized_default-rw-r--r-- 1 root root 4096 Dec 15 23:40 avoid_reset_quirk-r--r--r-- 1 root root 4096 Nov 26 21:21 bcdDevice-rw-r--r-- 1 root root 4096 Nov 26 21:21 bConfigurationValue-r--r--r-- 1 root root 4096 Nov 26 21:21 bDeviceClass-r--r--r-- 1 root root 4096 Nov 26 21:21 bDeviceProtocol-r--r--r-- 1 root root 4096 Nov 26 21:21 bDeviceSubClass-r--r--r-- 1 root root 4096 Dec 15 23:40 bmAttributes-r--r--r-- 1 root root 4096 Dec 15 23:40 bMaxPacketSize0-r--r--r-- 1 root root 4096 Dec 15 23:40 bMaxPower-r--r--r-- 1 root root 4096 Dec 15 23:40 bNumConfigurations-r--r--r-- 1 root root 4096 Dec 15 23:40 bNumInterfaces-r--r--r-- 1 root root 4096 Nov 26 21:21 busnum-r--r--r-- 1 root root 4096 Dec 15 23:40 configuration-r--r--r-- 1 root root 65553 Nov 26 21:21 descriptors-r--r--r-- 1 root root 4096 Dec 15 23:40 dev-r--r--r-- 1 root root 4096 Nov 26 21:21 devnum-r--r--r-- 1 root root 4096 Dec 15 23:40 devpathlrwxrwxrwx 1 root root 0 Nov 27 20:06 driver -> ../../../../../bus/usb/drivers/usb/drwxr-xr-x 3 root root 0 Dec 15 23:40 ep_00/-r--r--r-- 1 root root 4096 Nov 26 21:21 idProduct-r--r--r-- 1 root root 4096 Nov 26 21:21 idVendor-r--r--r-- 1 root root 4096 Dec 15 23:40 ltm_capable-r--r--r-- 1 root root 4096 Nov 26 21:21 manufacturer-r--r--r-- 1 root root 4096 Dec 15 23:40 maxchilddrwxr-xr-x 2 root root 0 Nov 26 21:21 power/-r--r--r-- 1 root root 4096 Nov 26 21:21 product-r--r--r-- 1 root root 4096 Dec 15 23:40 quirks-r--r--r-- 1 root root 4096 Nov 26 21:21 removable--w------- 1 root root 4096 Dec 15 23:40 remove-r--r--r-- 1 root root 4096 Nov 26 21:21 serial-r--r--r-- 1 root root 4096 Nov 26 21:21 speedlrwxrwxrwx 1 root root 0 Nov 26 21:21 subsystem -> ../../../../../bus/usb/-rw-r--r-- 1 root root 4096 Nov 26 21:21 uevent-r--r--r-- 1 root root 4096 Dec 15 23:40 urbnum-r--r--r-- 1 root root 4096 Dec 15 23:40 version二、使用debugfs1、挂载 debugfs 到 /sys/kernel/debug 路径下root@ubuntu:mount -t debugfs none /sys/kernel/debug2、执行上述步骤之后

在 /sys/kernel/debug 就会生成如下的文件

root@ubuntu:/sys/bus/usb/devices# cd /sys/kernel/debug/root@ubuntu:/sys/kernel/debug# lltotal 0drwx------ 22 root root 0 Nov 26 21:21 ./drwxr-xr-x 7 root root 0 Nov 26 21:21 ../drwxr-xr-x 2 root root 0 Nov 26 21:21 acpi/drwxr-xr-x 32 root root 0 Dec 4 16:30 bdi/drwxr-xr-x 2 root root 0 Nov 26 21:21 bluetooth/drwxr-xr-x 2 root root 0 Nov 26 21:21 cleancache/drwxr-xr-x 2 root root 0 Nov 26 21:21 dma_buf/drwxr-xr-x 4 root root 0 Nov 26 21:21 dri/drwxr-xr-x 2 root root 0 Nov 26 21:21 dynamic_debug/drwxr-xr-x 2 root root 0 Nov 26 21:21 extfrag/drwxr-xr-x 2 root root 0 Nov 26 21:21 frontswap/-r--r--r-- 1 root root 0 Nov 26 21:21 gpiodrwxr-xr-x 3 root root 0 Nov 26 21:21 hid/drwxr-xr-x 2 root root 0 Nov 26 21:21 kprobes/drwxr-xr-x 3 root root 0 Nov 26 21:21 kvm-guest/drwxr-xr-x 2 root root 0 Nov 26 21:21 mce/drwxr-xr-x 2 root root 0 Nov 26 21:21 pinctrl/-r--r--r-- 1 root root 0 Nov 26 21:21 pwmdrwxr-xr-x 2 root root 0 Nov 26 21:21 regmap/drwxr-xr-x 3 root root 0 Nov 26 21:21 regulator/-rw-r--r-- 1 root root 0 Nov 26 21:21 sched_features-r--r--r-- 1 root root 0 Nov 26 21:21 sleep_time-r--r--r-- 1 root root 0 Nov 26 21:21 suspend_statsdrwxr-xr-x 7 root root 0 Nov 26 21:21 tracing/drwxr-xr-x 3 root root 0 Nov 26 21:21 usb/drwxr-xr-x 2 root root 0 Nov 26 21:21 virtio-ports/-r--r--r-- 1 root root 0 Nov 26 21:21 vmmemctl-r--r--r-- 1 root root 0 Nov 26 21:21 wakeup_sourcesdrwxr-xr-x 2 root root 0 Nov 26 21:21 x86/3、cat 设备节点

执行下述命令之后会以特定格式打印目前USB总线上所有USB设备的信息如下：

root@ubuntu:/sys/kernel/debug# cat usb/devices T: Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2B: Alloc= 17/900 us ( 2%), #Int= 1, #Iso= 0D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1P: Vendor=1d6b ProdID=0001 Rev= 3.13S: Manufacturer=Linux 3.13.0-32-generic uhci_hcdS: Product=UHCI Host ControllerS: SerialNumber=0000:02:00.0C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hubE: Ad=81(I) Atr=03(Int.) MxPS= 2 Ivl=255msT: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1P: Vendor=0e0f ProdID=0003 Rev= 1.03S: Manufacturer=VMwareS: Product=VMware Virtual USB MouseC:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=usbhidE: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=1msT: Bus=02 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 3 Spd=12 MxCh= 7D: Ver= 1.10 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1P: Vendor=0e0f ProdID=0002 Rev= 1.00S: Product=VMware Virtual USB HubC:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hubE: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=255msT: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh= 6B: Alloc= 0/800 us ( 0%), #Int= 1, #Iso= 0D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1P: Vendor=1d6b ProdID=0002 Rev= 3.13S: Manufacturer=Linux 3.13.0-32-generic ehci_hcdS: Product=EHCI Host ControllerS: SerialNumber=0000:02:03.0C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr= 0mAI:* If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hubE: Ad=81(I) Atr=03(Int.) MxPS= 4 Ivl=256msT: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 7 Spd=480 MxCh= 0D: Ver= 2.00 Cls=ff(vend.) Sub=ff Prot=ff MxPS=64 #Cfgs= 1P: Vendor=0bda ProdID=0129 Rev=39.60S: Manufacturer=GenericS: Product=USB2.0-CRWS: SerialNumber=20100201396000000C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=500mAI:* If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=06 Prot=50 Driver=rts5139E: Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0msE: Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0msE: Ad=83(I) Atr=03(Int.) MxPS= 3 Ivl=64ms

至于信息的详细解析可以参照 Linux源代码中 Documentation/usb/proc_usb_info.txt 文件。

现摘录其中对该格式的详细解释：

Each line is tagged with a one-character ID for that line:T = Topology (etc.)B = Bandwidth (applies only to USB host controllers, which are virtualized as root hubs)D = Device descriptor info.P = Product ID info. (from Device descriptor, but they won't fit together on one line)S = String descriptors.C = Configuration descriptor info. (* = active configuration)I = Interface descriptor info.E = Endpoint descriptor info.Legend: d = decimal number (may have leading spaces or 0's) x = hexadecimal number (may have leading spaces or 0's) s = stringTopology info:T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd| | | | | | |||__MaxChildren| | | | | | ||__Device Speed in Mbps| | | | | | |__DeviceNumber| | | | | |__Count of devices at this level| | | | |__Connector/Port on Parent for this device| | | |__Parent DeviceNumber| | |__Level in topology for this bus| |__Bus number|__Topology info tag Speed may be:1.5 Mbit/s for low speed USB 12 Mbit/s for full speed USB 480 Mbit/s for high speed USB (added for USB 2.0); also used for Wireless USB, which has no fixed speed 5000 Mbit/s for SuperSpeed USB (added for USB 3.0) For reasons lost in the mists of time, the Port number is always too low by 1. For example, a device plugged into port 4 will show up with 'Port=03'.Bandwidth info:B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd| | | |__Number of isochronous requests| | |__Number of interrupt requests| |__Total Bandwidth allocated to this bus|__Bandwidth info tag Bandwidth allocation is an approximation of how much of one frame (millisecond) is in use. It reflects only periodic transfers, which are the only transfers that reserve bandwidth. Control and bulk transfers use all other bandwidth, including reserved bandwidth that is not used for transfers (such as for short packets). The percentage is how much of the 'reserved' bandwidth is scheduled by those transfers. For a low or full speed bus (loosely, 'USB 1.1'), 90% of the bus bandwidth is reserved. For a high speed bus (loosely, 'USB 2.0') 80% is reserved.Device descriptor info & Product ID info:D: Ver=x.xx Cls=xx(s) Sub=xx Prot=xx MxPS=dd #Cfgs=ddP: Vendor=xxxx ProdID=xxxx Rev=xx.xxwhereD: Ver=x.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd| || | | | |__NumberConfigurations| || | | |__MaxPacketSize of Default Endpoint| || | |__DeviceProtocol| || |__DeviceSubClass| ||__DeviceClass| |__Device USB version|__Device info tag #1whereP: Vendor=xxxx ProdID=xxxx Rev=xx.xx| | | |__Product revision number| | |__Product ID code| |__Vendor ID code|__Device info tag #2String descriptor info:S: Manufacturer=ssss| |__Manufacturer of this device as read from the device.| For USB host controller drivers (virtual root hubs) this may| be omitted, or (for newer drivers) will identify the kernel| version and the driver which provides this hub emulation.|__String info tagS: Product=ssss| |__Product description of this device as read from the device.| For older USB host controller drivers (virtual root hubs) this| indicates the driver; for newer ones, it's a product (and vendor)| description that often comes from the kernel's PCI ID database.|__String info tagS: SerialNumber=ssss| |__Serial Number of this device as read from the device.| For USB host controller drivers (virtual root hubs) this is| some unique ID, normally a bus ID (address or slot name) that| can't be shared with any other device.|__String info tagConfiguration descriptor info:C:* #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA| | | | | |__MaxPower in mA| | | | |__Attributes| | | |__ConfiguratioNumber| | |__NumberOfInterfaces| |__ '*' indicates the active configuration (others are ' ')|__Config info tag USB devices may have multiple configurations, each of which act rather differently. For example, a bus-powered configuration might be much less capable than one that is self-powered. Only one device configuration can be active at a time; most devices have only one configuration. Each configuration consists of one or more interfaces. Each interface serves a distinct 'function', which is typically bound to a different USB device driver. One common example is a USB speaker with an audio interface for playback, and a HID interface for use with software volume control.Interface descriptor info (can be multiple per Config):I:* If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=ssss| | | | | | | | |__Driver name| | | | | | | | or '(none)'| | | | | | | |__InterfaceProtocol| | | | | | |__InterfaceSubClass| | | | | |__InterfaceClass| | | | |__NumberOfEndpoints| | | |__AlternateSettingNumber| | |__InterfaceNumber| |__ '*' indicates the active altsetting (others are ' ')|__Interface info tag A given interface may have one or more 'alternate' settings. For example, default settings may not use more than a small amount of periodic bandwidth. To use significant fractions of bus bandwidth, drivers must select a non-default altsetting. Only one setting for an interface may be active at a time, and only one driver may bind to an interface at a time. Most devices have only one alternate setting per interface.Endpoint descriptor info (can be multiple per Interface):E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=dddss| || | |__Interval (max) between transfers| || |__EndpointMaxPacketSize| ||__Attributes(EndpointType)| |__EndpointAddress(I=In,O=Out)|__Endpoint info tag The interval is nonzero for all periodic (interrupt or isochronous) endpoints. For high speed endpoints the transfer interval may be measured in microseconds rather than milliseconds. For high speed periodic endpoints, the 'MaxPacketSize' reflects the per-microframe data transfer size. For 'high bandwidth' endpoints, that can reflect two or three packets (for up to 3KBytes every 125 usec) per endpoint. With the Linux-USB stack, periodic bandwidth reservations use the transfer intervals and sizes provided by URBs, which can be less than those found in endpoint descriptor.总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持好吧啦网。