Re: [PATCH v4 2/3] dt-bindings: sc16is7xx: Add compatible line for XR20M1172 UART

[Konstantin P.]

On Fri, Apr 19, 2024 at 5:24 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> On 19/04/2024 16:17, Konstantin P. wrote:
> > On Fri, Apr 19, 2024 at 5:08 PM Conor Dooley <conor@xxxxxxxxxx> wrote:
> >>
> >> On Fri, Apr 19, 2024 at 03:45:02PM +0300, Konstantin Pugin wrote:
> >>> From: Konstantin Pugin <ria.freelander@xxxxxxxxx>
> >>>
> >>> Add EXAR XR20M1172 UART compatible line into devicetree documentation.
> >>
> >> What you're doing is obvious from the diff, why this exar device is
> >> related to the nxp devices is what should be mentioned here.
> >>
> >> Thanks,
> >> Conor.
> >
> > It is already mentioned in cover letter and in previous patches in the
> > series. Do I need to repeat it in DTS patch?
> > If so, I will do it.
> >
> > Citation from my cover letter:
> >
> > EXAR XR20M1172 UART is mostly SC16IS762-compatible, but
> > it has additional register which can change UART multiplier
> > to 4x and 8x, similar to UPF_MAGIC_MULTIPLIER does. So, I used this
> > flag to guard access to its specific DLD register. It seems than
> > other EXAR SPI UART modules also have this register, but I tested
> > only XR20M1172.
> > Yes, in datasheet this register is called "DLD - Divisor Fractional"
> > or "DLD - Divisor Fractional Register", calling depends on datasheet
> > version.
>
> Commits must stand on their own. Cover letter is not merged. This is the
> place where you add new hardware, so here you describe and explain the
> hardware.

It is also described in patch 3 in the series. I need to repeat this
description in patch 2 too?

Cite from patch 3:

XR20M1172 register set is mostly compatible with SC16IS762, but it has
a support for additional division rates of UART with special DLD register.

> Best regards,
> Krzysztof
>