NVIDIA Tegra20/30 SoC serial controller

modulename: serial-tegra.ko

configname: CONFIG_SERIAL_TEGRA

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>NVIDIA Tegra20/30 SoC serial controller
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Support for the on-chip UARTs on the NVIDIA Tegra series SOCs
providing /dev/ttyTHS0, 1, 2, 3 and 4 (note, some machines may not
provide all of these ports, depending on how the serial port
are enabled). This driver uses the APB DMA to achieve higher baudrate
and better performance.

source code: