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Commit 697fb85f authored by Rodolfo Giometti's avatar Rodolfo Giometti Committed by Linus Torvalds
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pps: LinuxPPS clients support



Each PPS source can be registered/deregistered into the system by using
special modules called "clients".  They simply define the PPS sources'
attributes and implement the time signal registration mechanism.

This patch adds a special directory for such clients and adds a dummy
client that can be useful to test system integrity on real systems.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarRodolfo Giometti <giometti@linux.it>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 51e7364e
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@@ -30,4 +30,6 @@ config PPS_DEBUG
	  messages to the system log.  Select this if you are having a
	  messages to the system log.  Select this if you are having a
	  problem with PPS support and want to see more of what is going on.
	  problem with PPS support and want to see more of what is going on.


source drivers/pps/clients/Kconfig

endmenu
endmenu
+1 −0
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@@ -4,5 +4,6 @@


pps_core-y			:= pps.o kapi.o sysfs.o
pps_core-y			:= pps.o kapi.o sysfs.o
obj-$(CONFIG_PPS)		:= pps_core.o
obj-$(CONFIG_PPS)		:= pps_core.o
obj-y				+= clients/


ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
+18 −0
Original line number Original line Diff line number Diff line
#
# PPS clients configuration
#

if PPS

comment "PPS clients support"

config PPS_CLIENT_KTIMER
	tristate "Kernel timer client (Testing client, use for debug)"
	help
	  If you say yes here you get support for a PPS debugging client
	  which uses a kernel timer to generate the PPS signal.

	  This driver can also be built as a module.  If so, the module
	  will be called pps-ktimer.

endif
+9 −0
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#
# Makefile for PPS clients.
#

obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= pps-ktimer.o

ifeq ($(CONFIG_PPS_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
endif
+123 −0
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/*
 * pps-ktimer.c -- kernel timer test client
 *
 *
 * Copyright (C) 2005-2006   Rodolfo Giometti <giometti@linux.it>
 *
 *   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
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/pps_kernel.h>

/*
 * Global variables
 */

static int source;
static struct timer_list ktimer;

/*
 * The kernel timer
 */

static void pps_ktimer_event(unsigned long ptr)
{
	struct timespec __ts;
	struct pps_ktime ts;

	/* First of all we get the time stamp... */
	getnstimeofday(&__ts);

	pr_info("PPS event at %lu\n", jiffies);

	/* ... and translate it to PPS time data struct */
	ts.sec = __ts.tv_sec;
	ts.nsec = __ts.tv_nsec;

	pps_event(source, &ts, PPS_CAPTUREASSERT, NULL);

	mod_timer(&ktimer, jiffies + HZ);
}

/*
 * The echo function
 */

static void pps_ktimer_echo(int source, int event, void *data)
{
	pr_info("echo %s %s for source %d\n",
		event & PPS_CAPTUREASSERT ? "assert" : "",
		event & PPS_CAPTURECLEAR ? "clear" : "",
		source);
}

/*
 * The PPS info struct
 */

static struct pps_source_info pps_ktimer_info = {
	.name		= "ktimer",
	.path		= "",
	.mode		= PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
			  PPS_ECHOASSERT |
			  PPS_CANWAIT | PPS_TSFMT_TSPEC,
	.echo		= pps_ktimer_echo,
	.owner		= THIS_MODULE,
};

/*
 * Module staff
 */

static void __exit pps_ktimer_exit(void)
{
	del_timer_sync(&ktimer);
	pps_unregister_source(source);

	pr_info("ktimer PPS source unregistered\n");
}

static int __init pps_ktimer_init(void)
{
	int ret;

	ret = pps_register_source(&pps_ktimer_info,
				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
	if (ret < 0) {
		printk(KERN_ERR "cannot register ktimer source\n");
		return ret;
	}
	source = ret;

	setup_timer(&ktimer, pps_ktimer_event, 0);
	mod_timer(&ktimer, jiffies + HZ);

	pr_info("ktimer PPS source registered at %d\n", source);

	return  0;
}

module_init(pps_ktimer_init);
module_exit(pps_ktimer_exit);

MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
MODULE_LICENSE("GPL");