Hi Rohini,
The serial port associated with UARTX is referred as ttyOX.
So depending on the UART configured for Bluetooth the /dev/tty is defined.
Could you please provide me your board gpio_en_xxxxx.c file from path /kernel/drivers/bt_enable/gpio_en_xxxxx.c
For example for the board AM335x the file is /kernel/drivers/bt_enable/gpio_en_am335x.c
Thanks & Regards,
Sundeep.