[PATCH 16/16] arm64: dts: marvell: armada-3720-espressobin: fill UART nodes
Miquel RAYNAL
miquel.raynal at free-electrons.com
Fri Oct 13 00:01:19 PDT 2017
Hello Gregory,
On Thu, 12 Oct 2017 13:24:42 +0200
Gregory CLEMENT <gregory.clement at free-electrons.com> wrote:
> Hi Miquel,
>
> On lun., oct. 09 2017, Miquel RAYNAL
> <miquel.raynal at free-electrons.com> wrote:
>
> > Hi Thomas, Gregory,
> >
> > On Fri, 6 Oct 2017 15:15:21 +0200
> > Thomas Petazzoni <thomas.petazzoni at free-electrons.com> wrote:
> >
> >> Hello,
> >>
> >> On Fri, 06 Oct 2017 15:01:18 +0200, Gregory CLEMENT wrote:
> >>
> >> > /*
> >> > * To enable the second UART on J17 (pins 24,26) refer to the
> >> > uart1
> >> > * node from armada-3720-db.dts.
> >> > * Note that TX and RX signal are the ones coming directly from
> >> > the SoC:
> >> > * 1.8V TTL.
> >> > */
> >>
> >> One issue with this comment (and Miquèl's version as well) is that
> >> it does not explain why you don't enable this UART by default.
> >>
> >> The real reason is in the commit log from Miquèl, and should
> >> probably be part of the comment. Perhaps something like:
> >>
> >> /*
> >>
> >> * Connector J17 (pins X, Y, Z) exposes a number of different
> >> * features:
> >> * - UART1 (pins 24 = RX, pins 26 = TX), see armada-3720-db.dts
> >> for an
> >> * example on how to enable UART1. Beware that the signals are
> >> 1.8V
> >> * TTL.
> >> * - SPIxyz
> >> * - I2Cxyz
> >> */
> >
> > Thanks for both your comments, there is my version, inspired from
> > both comments:
> >
> > /*
> > * Connector J17 exposes a number of different features. Some pins
> > are
> > * multiplexed. This is the case for the UART1 feature (pins 24 =
> > RX,
> > * pins 26 = TX). See armada-3720-db.dts for an example of how to
> > enable it.
> > * Beware that the signals are 1.8V TTL.
> > */
>
> Seems good for me however I prefer Thomas version, easier to read and
> to extend latter with the description of other pins if needed.
Ok, I reused the 'dash' presentation to be later extended.
See v2 coming soon.
Thanks,
Miquèl
>
> Gregory
>
> >
> > Thanks,
> > Miquèl
> >
> >>
> >> Otherwise, it's not clear at all why you don't just enable UART1.
> >> Or perhaps I misunderstood Miquèl's commit log ?
> >>
> >> Best regards,
> >>
> >> Thomas
> >
> >
> >
> > --
> > Miquel Raynal, Free Electrons
> > Embedded Linux and Kernel engineering
> > http://free-electrons.com
>
--
Miquel Raynal, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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