USB: serial: f81534: add H/W disable port support
The F81532/534 can be disable port by manufacturer with
following H/W design.
1: Connect DCD/DSR/CTS/RI pin to ground.
2: Connect RX pin to ground.
In driver, we'll implements some detect method likes following:
1: Read MSR.
2: Turn MCR LOOP bit on, off and read LSR after delay with 60ms.
It'll contain BREAK status in LSR.
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
1 file changed