Re: Add hardware handshaking to pseudo-tty and USB serial gadget

[Grant Edwards <grant.b.edwards@gmail.com>]

On 2013-03-21, Peter Hurley <peter@hurleysoftware.com> wrote:
> On Thu, 2013-03-21 at 20:38 +0000, Grant Edwards wrote:
>> On 2013-03-21, Craig McQueen <craig.mcqueen@beamcommunications.com> wrote:

>> > It sounds as though people have done pseudo-ttys with HW handshaking
>> > support--eg tty0tty project. However I'd rather implement this
>> > function in the kernel pseudo-terminal driver itself. Is there any
>> > reason not to do that?
>> 
>> No reason other than you and I are the only two people who care about
>> it. :)
>
> Assuming you're leaning toward an in-kernel solution, why not just
> implement a new tty driver that behaves like a local serial port?

I've been thinking about trying to do that except making it a
serial_core driver on the slave side rather than a tty driver.  I just
converted a tty driver to the serial-core API and the code-size
dropped by almost 70% (hopefully the undiscovered bug count dropped as
well).  I hadn't decided what to do for a master-side API.  I'd
probably abandon the standard tty API altogether and do something from
scratch as a plain char device driver with custom ioctl calls.

-- 
Grant Edwards               grant.b.edwards        Yow! A dwarf is passing out
                                  at               somewhere in Detroit!
                              gmail.com