The kernel module ftdio_sio isn't part of the TK1 kernel built, so you have to either recompile the kernel modules from their sources or use the pre-compile module and place it in /lib/modules/3.10.40/kernel/drivers/usb/serial/. Then you must add a rule to allow any user to use the usb port in /etc/udev/rules.d/55-tegraserial.rules: KERNEL=="ttyUSB0", MODE="0666". Finally it's better to force the ftdi module to load at boot by putting it in /etc/modules list file. To allow the module to be autolaod at boot you also need to run sudo depmod -a. Then you can try sudo modprobe ftdio_sio to see if it works and lsit the loaded modules with lsmod.
The kernel module ftdio_sio isn't part of the TK1 kernel built, so you have to either recompile the kernel modules from their sources or use the pre-compile module and place it in /lib/modules/3.10.40/kernel/drivers/usb/serial/. Then you must add a rule to allow any user to use the usb port in /etc/udev/rules.d/55-tegraserial.rules: KERNEL=="ttyUSB0", MODE="0666". Finally it's better to force the ftdi module to load at boot by putting it in /etc/modules list file. To allow the module to be autolaod at boot you also need to run sudo depmod -a. Then you can try sudo modprobe ftdio_sio to see if it works and lsit the loaded modules with lsmod.