Enumerate USB devices C / C++ embedded Linux

schliz · 10-19-2011, 07:10 AM

I need to enumerate my USB devices on my Angstrom embedded Linux device in C / C++.
I use codesourcery Sourcery_G++_Lite 2009q3.

For Ubuntu Desktop I found:
#include <libudev.h>
libudev-dev

but how to use that for the embedded device.

Thank you very much in advance.

Georg

sunnydrake · 10-19-2011, 07:56 AM

ls /dev/bus/usb/ ? or grab source of lsusb and look

schliz · 10-19-2011, 08:46 AM

ls reports:

ls /dev/bus/usb
001 002

how can I use that?

Thank's again.
Georg

schliz · 10-20-2011, 02:36 AM

I was now able to run the following program using libusb on my Angstrom board:
http://www.dreamincode.net/forums/to...ing-libusb-10/
http://libusb.sourceforge.net/api-1.0/index.html

I get now get the USB class code, but how can I now determine sdXY?

Thank you in advance.

Georg

sunnydrake · 10-20-2011, 07:15 AM

/dev/bus/usb/ give access to usb bus! Device detection and /dev/sdXX creation made by kernel and/or udev.
so you need to decide:you need to work with raw data on usb bus like sending enumerate signals etc.. or just list detected by kernel/udev and created devices in system = this is different levels with different api.
lsusb is tool, it's enumerate and print usb devices info. look code at http://www.koders.com/c/fidCE88EE326...EA27E46BD.aspx
list devices part

Quote:

static int list_devices(int busnum, int devnum, int vendorid, int productid)
{
struct usb_bus *bus;
struct usb_device *dev;
char vendor[128], product[128];
int status;

status=1; /* 1 device not found, 0 device found */
for (bus = usb_busses; bus; bus = bus->next) {

sunnydrake · 10-20-2011, 07:27 AM

about mknod /dev/sdXX here some info when i insert flash drive

Quote:

sunnydrake@main:~$ udevadm monitor
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[6489.821719] add /devices/pci0000:00/0000:00:02.1/usb1/1-3 (usb)
KERNEL[6489.823127] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0 (usb)
KERNEL[6489.826142] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7 (scsi)
KERNEL[6489.826205] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/scsi_host/host7 (scsi_host)
UDEV [6489.832780] add /devices/pci0000:00/0000:00:02.1/usb1/1-3 (usb)
UDEV [6489.836369] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0 (usb)
UDEV [6489.839974] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7 (scsi)
UDEV [6489.842296] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/scsi_host/host7 (scsi_host)
KERNEL[6490.864441] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0 (scsi)
KERNEL[6490.864505] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0 (scsi)
KERNEL[6490.864535] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_disk/7:0:0:0 (scsi_disk)
KERNEL[6490.864563] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_device/7:0:0:0 (scsi_device)
KERNEL[6490.868426] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_generic/sg2 (scsi_generic)
UDEV [6490.868485] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0 (scsi)
KERNEL[6490.868520] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/bsg/7:0:0:0 (bsg)
UDEV [6490.868549] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0 (scsi)
UDEV [6490.870417] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_device/7:0:0:0 (scsi_device)
KERNEL[6490.871136] add /devices/virtual/bdi/8:32 (bdi)
UDEV [6490.874909] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/bsg/7:0:0:0 (bsg)
UDEV [6490.876379] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_disk/7:0:0:0 (scsi_disk)
UDEV [6490.878567] add /devices/virtual/bdi/8:32 (bdi)
UDEV [6490.880498] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/scsi_generic/sg2 (scsi_generic)
KERNEL[6490.953707] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/block/sdc (block)
KERNEL[6490.953769] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/block/sdc/sdc1 (block)
UDEV [6491.141430] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/block/sdc (block)
UDEV [6491.253973] add /devices/pci0000:00/0000:00:02.1/usb1/1-3/1-3:1.0/host7/target7:0:0/7:0:0:0/block/sdc/sdc1 (block)