gprs usb modem

I am using D-link DWP-157 USB gprs modem for viola carrier board V1.2A with Linux as OS. I have added following lines


in /arch/arm/configs/colibri_vf_defconfig file and compiled the kernel. But still, I am not getting interface like ttyUSB0.
Please let me know the exact drivers needed to add for D-Link modem that I have specified.

USB_SERIAL_CP210x is for the USB to serial converter and has got nothing to with the modem. Please provide the appropriate output of lsusb and usb-devices.

Output of lsusb is:
Bus 001 Device 004: ID 2001:a707 D-Link Corp.

Please have a look at the following blog post. Along with the userspace ppp package, it will be also advised to install the usb-modeswitch, usb-modeswitch-data. For information on why modeswitch is required, see here.