Received-SPF: pass (google.com: domain of linux-kernel+bounces-172612-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Date: Wed, 8 May 2024 08:52:24 +0700
From: Bagas Sanjaya <bagasdotme@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <robh@kernel.org>, Jiri Slaby <jirislaby@kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Serial <linux-serial@vger.kernel.org>,
	Elvis <elvisimprsntr@gmail.com>
Subject: Fwd: Add method to allow switching kernel level PPS signal from DCD
 to CTS serial pin
Message-ID: <Zjra2GZIDC7BPoZx@archie.me>
Precedence: bulk
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="ceDjgLgiBjV9uhOH"
Content-Disposition: inline


--ceDjgLgiBjV9uhOH
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Hi Greg, hi maintainers,

On Bugzilla, Elvis <elvisimprsntr@gmail.com> requested a new RJ45 UART
feature [1]:

> BACKGROUND
>=20
> There are appliances that do not have a full DE9 RS-232 port and only RJ4=
5 COM ports, which do not include the DCD pin required for PPS signal detec=
tion. =20
>=20
> RJ45 COM port do include the CTS input pin #8, which can be used for PPS =
signal detection.  This is a feature that has been available in FreeBSD for=
 some time. =20
>=20
> https://man.freebsd.org/cgi/man.cgi?query=3Duart
>=20
> FreeBSD allows switching from DCD to CTS pin on the fly using a system tu=
nable in a loader.conf file.  Example: dev.uart.0.pps_mode=3D"1"
>=20
> This allow one to connect a serial GPS receiver with PPS output to a RJ45=
 COM port for a Stratum 0 GPS+PPS source. =20
>=20
> https://github.com/elvisimprsntr/pfsense-ntp-gps?tab=3Dreadme-ov-file
>=20
> KERNAL PATCH HACKS
>=20
> Some kernel patches have demonstrated receiving PPS on the CTS pin, but r=
equires hacking up the kernel and will will not persist on kernel update to=
 new installations. =20
>=20
> https://github.com/not1337/pps-stuff
>=20
> FEATURE REQUEST
>=20
> Add a tunable option to allow the end user to switch between PPS on DCD t=
o CTS pin, similar to the way FreeBSD does.

What do you think about above feature request?

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=3D218813

--=20
An old man doll... just what I always wanted! - Clara

--ceDjgLgiBjV9uhOH
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iHUEABYKAB0WIQSSYQ6Cy7oyFNCHrUH2uYlJVVFOowUCZjra0QAKCRD2uYlJVVFO
o/iyAQDHM8NvcDtZ8zMGlWMT2semUK8Jnc39VvUKdDj0DgrBvAEA66gysRM5CVqY
hSTSD2PPhC+SKhMd1bUEpl6tZOM1MA8=
=RSX+
-----END PGP SIGNATURE-----

--ceDjgLgiBjV9uhOH--