ST-Link/V2-1 driver on Linux

The ST-Link/V2-1 is supported by libusb but the device has to be named with a udev rule.

Download the following tarball which contains 49-stlinkv2.rules
- stlink_udev_rule.tar.bz2

# stm32 discovery boards, with onboard st/linkv2
# ie, STM32L, STM32F4.
# STM32VL has st/linkv1, which is quite different

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="3748", \
    MODE:="0666", \
    SYMLINK+="stlinkv2_%n"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", \
    KERNEL!="sd*", KERNEL!="sg*", KERNEL!="tty*", SUBSYSTEM!="bsg", \
    MODE:="0666", \
    SYMLINK+="stlinkv2_%n"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", \
    KERNEL=="sd*", MODE:="0666", \
    SYMLINK+="stlinkv2_disk"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", \
    KERNEL=="sg*", MODE:="0666", \
    SYMLINK+="stlinkv2_raw_scsi"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", \
    SUBSYSTEM=="bsg", MODE:="0666", \
    SYMLINK+="stlinkv2_block_scsi"

SUBSYSTEMS=="usb", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", \
    KERNEL=="tty*", MODE:="0666", \
    SYMLINK+="stlinkv2_console"

# If you share your linux system with other users, or just don't like the
# idea of write permission for everybody, you can replace MODE:="0666" with
# OWNER:="yourusername" to create the device owned by you, or with
# GROUP:="somegroupname" and control access using standard unix groups.

Extract the tarball into /etc/udev/rules.d under root permission
$ sudo tar -xf stlink_udev_rule.tar.bz2 -C /etc/udev/rules.d

source: http://www.openstm32.org/Installing+System+Workbench+for+STM32+from+Eclipse
(may be you have to register and login to access the page)