Re: [PATCH v3 5/5] serial: 8250_dw: add em485 support

From: Andy Shevchenko
Date: Tue Feb 02 2021 - 06:27:17 EST


On Tue, Feb 02, 2021 at 01:31:17AM +0100, Giulio Benetti wrote:
> Il 18/05/2020 17:21, Andy Shevchenko ha scritto:
> > On Sun, May 17, 2020 at 11:56:10PM +0200, Heiko Stuebner wrote:
> > > From: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx>
> > >
> > > Need to use rs485 transceiver so let's use existing em485 485 emulation
> > > layer on top of 8250.
> > >
> > > Add rs485_config callback to port and uses the standard em485 start and
> > > stop helpers.
> >
> > Would it prevent to use native RS485 support?
>
> 8250_dw doesn't have a native RS485 support, do you mean using hardware
> RTS assertion? Anyway at the moment it's not present. This would be the
> first rs485 support added to 8250_dw.

DW v4.0+ has it.

--
With Best Regards,
Andy Shevchenko