[src/trunk]: src Add a 1PPS-over-GPIO driver, originally by Brad...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/96e3fc7a1fb6
branches:  trunk
changeset: 319203:96e3fc7a1fb6
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Sun May 20 15:15:40 2018 +0000

description:
Add a 1PPS-over-GPIO driver, originally by Brad Spencer, with changes by
me to adapt to the new GPIO interrupt interface and support a wider variety
of GPIO pin configuations.

PR kern/51676

(Oops, forgot to "cvs add" these items previously.)

diffstat:

 share/man/man4/gpiopps.4           |  106 +++++++++++++++++++++++++++++++++++++
 sys/modules/gpiopps/Makefile       |   13 ++++
 sys/modules/gpiopps/gpiopps.ioconf |    8 ++
 3 files changed, 127 insertions(+), 0 deletions(-)

diffs (139 lines):

diff -r 8353fa85d1ff -r 96e3fc7a1fb6 share/man/man4/gpiopps.4
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/share/man/man4/gpiopps.4  Sun May 20 15:15:40 2018 +0000
@@ -0,0 +1,106 @@
+.\" $NetBSD: gpiopps.4,v 1.1 2018/05/20 15:15:40 thorpej Exp $
+.\"
+.\" Copyright (c) 2016 Brad Spencer <brad%anduin.eldar.org@localhost>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd May 11, 2018
+.Dt GPIOPPS 4
+.Os
+.Sh NAME
+.Nm gpiopps
+.Nd install a PPS handler on GPIO pins
+.Sh SYNOPSIS
+.Cd "gpiopps* at gpio? offset 0 mask 0x1 flag 0x0"
+.Sh DESCRIPTION
+The
+.Nm
+driver provides a 1PPS handler using the PPSAPI on one or two GPIO pins.
+.Pp
+The base pin number is specified in the kernel configuration file with the
+.Ar offset
+locator.
+The
+.Ar mask
+should have 1 or 2 bits set, indicating which pins offset from the
+base pin should be used
+.Pq 0 .. 31 .
+Pin configurations are discussed below.
+.Pp
+The
+.Ar flag
+locator modifies the pin configuraiton:
+.Bl -tag -width "XXXXXXXX"
+.It Dv 0x01
+The PPS ASSERT signal should be triggered on the negative
+.Pq falling
+edge of the
+assert pin.
+The default is to trigger on the positive
+.Pq rising
+edge of the pin.
+.It Dv 0x02
+By default,
+.Nm
+will use double-edge triggering when only a single pin is specified
+and the underlying GPIO hardware supports it.
+This flag disables the use of double-edge triggering.
+.El
+.Pp
+If a single pin is specified,
+.Nm
+uses double-edge triggering to support ASSERT and CLEAR PPS signals.
+If the underlying GPIO hardware does not support double-edge triggering,
+or if this feature is diabled in the
+.Ar flag
+locator, then only ASSERT will be signaled on the specified edge.
+.Pp
+If two pins are specified, the first pin is used to trigger the
+ASSERT signal and the second pin is used to trigger the CLEAR
+signal.
+The ASSERT pin's trigger edge is specified by by the
+.Ar flag
+locator, and the CLEAR pin triggers on the opposite edge.
+This allows ASSERT and CLEAR signals to be triggered even if the underlying
+GPIO hardware does not support double-edge triggering.
+In this scenario, both GPIO pins would be connected in parallel to the
+device sending the 1PPS signals.
+.Pp
+The
+.Ar offset ,
+.Ar mask ,
+and
+.Ar flag
+locators can also be specified when
+.Nm
+is attached at runtime using the
+.Dv GPIOATTACH
+.Xr ioctl 2
+on the
+.Xr gpio 4
+device.
+.Sh SEE ALSO
+.Xr gpio 4 ,
+.Xr drvctl 8 ,
+.Xr gpioctl 8
+.Sh HISTORY
+The
+.Nm
+driver first appeared in
+.Nx 9.0 .
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+driver was written by
+.An Brad Spencer Aq Mt brad%anduin.eldar.org@localhost
diff -r 8353fa85d1ff -r 96e3fc7a1fb6 sys/modules/gpiopps/Makefile
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/modules/gpiopps/Makefile      Sun May 20 15:15:40 2018 +0000
@@ -0,0 +1,13 @@
+#      $NetBSD: Makefile,v 1.1 2018/05/20 15:15:41 thorpej Exp $
+
+.include "../Makefile.inc"
+
+.PATH:         ${S}/dev/gpio
+
+KMOD=          gpiopps
+IOCONF=                gpiopps.ioconf
+SRCS=          gpiopps.c
+
+CPPFLAGS+=     -I${S}/gpio
+
+.include <bsd.kmodule.mk>
diff -r 8353fa85d1ff -r 96e3fc7a1fb6 sys/modules/gpiopps/gpiopps.ioconf
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/sys/modules/gpiopps/gpiopps.ioconf        Sun May 20 15:15:40 2018 +0000
@@ -0,0 +1,8 @@
+#      $NetBSD: gpiopps.ioconf,v 1.1 2018/05/20 15:15:41 thorpej Exp $
+
+ioconf         gpiopps
+
+include                "conf/files"
+
+pseudo-root    gpio*
+gpiopps*       at gpio? offset ? mask ? flag ?