[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <0d3ebd1dec9baec2f1d6cb08f86623bd5ef13139.1555382110.git.mchehab+samsung@kernel.org>
Date: Mon, 15 Apr 2019 23:55:52 -0300
From: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
To: Linux Doc Mailing List <linux-doc@...r.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>,
Mauro Carvalho Chehab <mchehab@...radead.org>,
linux-kernel@...r.kernel.org, Jonathan Corbet <corbet@....net>
Subject: [PATCH 27/57] docs: pps/pps.txt convert it to ReST and move to API book
This file is already in a good shape: just its title and
adding some literal block markups is needed for it to be
part of the document.
While it has a small chapter with sysfs stuff, most of
the document is focused on driver development.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@...nel.org>
---
Documentation/pps/pps.txt | 67 ++++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 33 deletions(-)
diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt
index 99f5d8c4c652..262151a6dad5 100644
--- a/Documentation/pps/pps.txt
+++ b/Documentation/pps/pps.txt
@@ -1,8 +1,8 @@
+======================
+PPS - Pulse Per Second
+======================
- PPS - Pulse Per Second
- ----------------------
-
-(C) Copyright 2007 Rodolfo Giometti <giometti@...eenne.com>
+Copyright (C) 2007 Rodolfo Giometti <giometti@...eenne.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -88,7 +88,7 @@ Coding example
--------------
To register a PPS source into the kernel you should define a struct
-pps_source_info as follows:
+pps_source_info as follows::
static struct pps_source_info pps_ktimer_info = {
.name = "ktimer",
@@ -101,12 +101,12 @@ pps_source_info as follows:
};
and then calling the function pps_register_source() in your
-initialization routine as follows:
+initialization routine as follows::
source = pps_register_source(&pps_ktimer_info,
PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
-The pps_register_source() prototype is:
+The pps_register_source() prototype is::
int pps_register_source(struct pps_source_info *info, int default_params)
@@ -118,7 +118,7 @@ pps_source_info which describe the capabilities of the driver).
Once you have registered a new PPS source into the system you can
signal an assert event (for example in the interrupt handler routine)
-just using:
+just using::
pps_event(source, &ts, PPS_CAPTUREASSERT, ptr)
@@ -134,13 +134,13 @@ Please see the file drivers/pps/clients/pps-ktimer.c for example code.
SYSFS support
-------------
-If the SYSFS filesystem is enabled in the kernel it provides a new class:
+If the SYSFS filesystem is enabled in the kernel it provides a new class::
$ ls /sys/class/pps/
pps0/ pps1/ pps2/
Every directory is the ID of a PPS sources defined in the system and
-inside you find several files:
+inside you find several files::
$ ls -F /sys/class/pps/pps0/
assert dev mode path subsystem@
@@ -148,7 +148,7 @@ inside you find several files:
Inside each "assert" and "clear" file you can find the timestamp and a
-sequence number:
+sequence number::
$ cat /sys/class/pps/pps0/assert
1170026870.983207967#8
@@ -175,11 +175,11 @@ and the userland tools available in your distribution's pps-tools package,
http://linuxpps.org , or https://github.com/redlab-i/pps-tools.
Once you have enabled the compilation of pps-ktimer just modprobe it (if
-not statically compiled):
+not statically compiled)::
# modprobe pps-ktimer
-and the run ppstest as follow:
+and the run ppstest as follow::
$ ./ppstest /dev/pps1
trying PPS source "/dev/pps1"
@@ -204,26 +204,27 @@ nor affordable. The cheap way is to load a PPS generator on one of the
computers (master) and PPS clients on others (slaves), and use very simple
cables to deliver signals using parallel ports, for example.
-Parallel port cable pinout:
-pin name master slave
-1 STROBE *------ *
-2 D0 * | *
-3 D1 * | *
-4 D2 * | *
-5 D3 * | *
-6 D4 * | *
-7 D5 * | *
-8 D6 * | *
-9 D7 * | *
-10 ACK * ------*
-11 BUSY * *
-12 PE * *
-13 SEL * *
-14 AUTOFD * *
-15 ERROR * *
-16 INIT * *
-17 SELIN * *
-18-25 GND *-----------*
+Parallel port cable pinout::
+
+ pin name master slave
+ 1 STROBE *------ *
+ 2 D0 * | *
+ 3 D1 * | *
+ 4 D2 * | *
+ 5 D3 * | *
+ 6 D4 * | *
+ 7 D5 * | *
+ 8 D6 * | *
+ 9 D7 * | *
+ 10 ACK * ------*
+ 11 BUSY * *
+ 12 PE * *
+ 13 SEL * *
+ 14 AUTOFD * *
+ 15 ERROR * *
+ 16 INIT * *
+ 17 SELIN * *
+ 18-25 GND *-----------*
Please note that parallel port interrupt occurs only on high->low transition,
so it is used for PPS assert edge. PPS clear edge can be determined only
--
2.20.1
Powered by blists - more mailing lists