RE: [PATCH v2 tty-next 2/3] 8250: microchip: pci1xxxx: Add rs485 support to quad-uart driver.

[Kumaravel.Thiagarajan]

> -----Original Message-----
> From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> Sent: Monday, October 3, 2022 2:51 PM
> To: Kumaravel Thiagarajan - I21417 <Kumaravel.Thiagarajan@xxxxxxxxxxxxx>
> Subject: Re: [PATCH v2 tty-next 2/3] 8250: microchip: pci1xxxx: Add rs485
> support to quad-uart driver.
> 
> On Sat, 1 Oct 2022, Kumaravel Thiagarajan wrote:
> 
> > pci1xxxx uart supports rs485 mode of operation in the hardware with
> > auto-direction control with configurable delay for releasing RTS after
> > the transmission. This patch adds support for the rs485 mode.
> >
> > Signed-off-by: Kumaravel Thiagarajan
> > <kumaravel.thiagarajan@xxxxxxxxxxxxx>
> > ---
> > Changes in v2:
> > - move pci1xxxx_rs485_config to a separate patch with
> >   pci1xxxx_rs485_supported.
> > ---
> >  drivers/tty/serial/8250/8250_pci1xxxx.c | 57
> > +++++++++++++++++++++++++
> >  1 file changed, 57 insertions(+)
> >
> > diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c
> > b/drivers/tty/serial/8250/8250_pci1xxxx.c
> > index 41a4b94f52b4..999e5a284266 100644
> > --- a/drivers/tty/serial/8250/8250_pci1xxxx.c
> > +++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
> > +
> > +             if (rs485->delay_rts_after_send) {
> > +                     baud_period_in_ns = ((clock_div >> 8) * 16);
> 
> Is this 16 perhaps UART_BIT_SAMPLE_CNT?
Yes. Is there any macro definition for that? I could not find any definition in the above name.

Thank You.

Regards,
Kumar