From: Sean Wang <sean.wang@xxxxxxxxxxxx> >On Thu, Apr 23, 2020 at 02:02:08AM +0800, sean.wang@xxxxxxxxxxxx wrote: >> From: Sean Wang <sean.wang@xxxxxxxxxxxx> >> >> Bluetooth Interface (BTIF) is designed dedicatedly for MediaTek SOC >> with BT in order to be instead of the UART interface between BT module >> and Host CPU, and not exported to user space to access. >> >> As the UART design, BTIF will be an APB slave and can transmit or >> receive data by MCU access, but doesn't provide termios function like >> baudrate and flow control setup. > >Why does it matter? If the connection isn't exported to userspace, who would run those termios functions on the port? The bluetooth driver would use BTIF device as a serdev. The termios function would be called in kernelspace from ttyport_open and then to tty_set_termios defined in drivers/tty/serdev/serdev-ttyport.c. > >thanks, > >greg k-h
