From 28aedd7ee214eb63a2e6924b5ec2b081aa7b3953 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 12 Jun 2019 14:52:56 -0300 Subject: [PATCH] docs: pps.txt: convert to ReST and rename to pps.rst 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. As it describes a kernel API, move it to the driver-api directory. In order to avoid conflicts, let's add an :orphan: tag to it, to be removed when added to the driver-api book. Signed-off-by: Mauro Carvalho Chehab Acked-by: Rodolfo Giometti Signed-off-by: Jonathan Corbet --- .../{pps/pps.txt => driver-api/pps.rst} | 67 ++++++++++--------- MAINTAINERS | 2 +- 2 files changed, 36 insertions(+), 33 deletions(-) rename Documentation/{pps/pps.txt => driver-api/pps.rst} (89%) diff --git a/Documentation/pps/pps.txt b/Documentation/driver-api/pps.rst similarity index 89% rename from Documentation/pps/pps.txt rename to Documentation/driver-api/pps.rst index 99f5d8c4c652..1456d2c32ebd 100644 --- a/Documentation/pps/pps.txt +++ b/Documentation/driver-api/pps.rst @@ -1,8 +1,10 @@ +:orphan: - PPS - Pulse Per Second - ---------------------- +====================== +PPS - Pulse Per Second +====================== -(C) Copyright 2007 Rodolfo Giometti +Copyright (C) 2007 Rodolfo Giometti 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 +90,7 @@ 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 +103,12 @@ 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 +120,7 @@ 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 +136,13 @@ 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 +150,7 @@ 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 +177,11 @@ 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 +206,27 @@ 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 diff --git a/MAINTAINERS b/MAINTAINERS index ac88ed99fca5..aae3bd8a19f4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12659,7 +12659,7 @@ M: Rodolfo Giometti W: http://wiki.enneenne.com/index.php/LinuxPPS_support L: linuxpps@ml.enneenne.com (subscribers-only) S: Maintained -F: Documentation/pps/ +F: Documentation/driver-api/pps.rst F: Documentation/devicetree/bindings/pps/pps-gpio.txt F: Documentation/ABI/testing/sysfs-pps F: drivers/pps/