This Patch adds PPS (Pulse per Second) Support to Openwrt 2.6.23 (its deprecated before 2.6.23). Its common to use PPS to sync your PC Clock with GPS or DCF77 clocks via NTPd.

I've taken this Patch from http://wiki.enneenne.com/index.php/LinuxPPS_support

Signed-off-by: Frithjof Hammer <[email protected]>

SVN-Revision: 10619

target/linux/generic-2.6/patches-2.6.23/230-pps_support.patch

@@ -0,0 +1,2215 @@
+diff --git a/Documentation/pps/Makefile b/Documentation/pps/Makefile
+new file mode 100644
+index 0000000..a2660a2
+--- /dev/null
++++ b/Documentation/pps/Makefile
+@@ -0,0 +1,27 @@
++TARGETS = ppstest ppsctl
++
++CFLAGS += -Wall -O2 -D_GNU_SOURCE
++CFLAGS += -I .
++CFLAGS += -ggdb
++
++# -- Actions section ----------------------------------------------------------
++
++.PHONY : all depend dep
++
++all : .depend $(TARGETS)
++
++.depend depend dep :
++	$(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
++
++ifeq (.depend,$(wildcard .depend))
++include .depend
++endif
++
++
++# -- Clean section ------------------------------------------------------------
++
++.PHONY : clean
++
++clean :
++	rm -f *.o *~ core .depend
++	rm -f ${TARGETS}
+diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt
+new file mode 100644
+index 0000000..9538925
+--- /dev/null
++++ b/Documentation/pps/pps.txt
+@@ -0,0 +1,170 @@
++
++			PPS - Pulse Per Second
++			----------------------
++
++(C) Copyright 2007 Rodolfo Giometti <[email protected]>
++
++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.
++
++
++
++Overview
++--------
++
++LinuxPPS provides a programming interface (API) to define into the
++system several PPS sources.
++
++PPS means "pulse per second" and a PPS source is just a device which
++provides a high precision signal each second so that an application
++can use it to adjust system clock time.
++
++A PPS source can be connected to a serial port (usually to the Data
++Carrier Detect pin) or to a parallel port (ACK-pin) or to a special
++CPU's GPIOs (this is the common case in embedded systems) but in each
++case when a new pulse comes the system must apply to it a timestamp
++and record it for the userland.
++
++Common use is the combination of the NTPD as userland program with a
++GPS receiver as PPS source to obtain a wallclock-time with
++sub-millisecond synchronisation to UTC.
++
++
++RFC considerations
++------------------
++
++While implementing a PPS API as RFC 2783 defines and using an embedded
++CPU GPIO-Pin as physical link to the signal, I encountered a deeper
++problem:
++
++   At startup it needs a file descriptor as argument for the function
++   time_pps_create().
++
++This implies that the source has a /dev/... entry. This assumption is
++ok for the serial and parallel port, where you can do something
++useful besides(!) the gathering of timestamps as it is the central
++task for a PPS-API. But this assumption does not work for a single
++purpose GPIO line. In this case even basic file-related functionality
++(like read() and write()) makes no sense at all and should not be a
++precondition for the use of a PPS-API.
++
++The problem can be simply solved if you consider that a PPS source is
++not always connected with a GPS data source.
++
++So your programs should check if the GPS data source (the serial port
++for instance) is a PPS source too, otherwise they should provide the
++possibility to open another device as PPS source.
++
++In LinuxPPS the PPS sources are simply char devices usually mapped
++into files /dev/pps0, /dev/pps1, etc..
++
++
++Coding example
++--------------
++
++To register a PPS source into the kernel you should define a struct
++pps_source_info_s as follow:
++
++    static struct pps_source_info_s 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,
++    };
++
++and then calling the function pps_register_source() in your
++intialization routine as follow:
++
++    source = pps_register_source(&pps_ktimer_info,
++			PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
++
++The pps_register_source() prototype is:
++
++  int pps_register_source(struct pps_source_info_s *info, int default_params)
++
++where "info" is a pointer to a structure that describes a particular
++PPS source, "default_params" tells the system what the initial default
++parameters for the device should be (is obvious that these parameters
++must be a subset of ones defined into the struct
++pps_source_info_s 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:
++
++    pps_event(source, PPS_CAPTUREASSERT, ptr);
++
++The same function may also run the defined echo function
++(pps_ktimer_echo(), passing to it the "ptr" pointer) if the user
++asked for that... etc..
++
++Please see the file drivers/pps/clients/ktimer.c for an example code.
++
++
++SYSFS support
++-------------
++
++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 into the system and
++inside you find several files:
++
++    $ ls /sys/class/pps/pps0/
++    assert	clear  echo  mode  name  path  subsystem@  uevent
++
++Inside each "assert" and "clear" file you can find the timestamp and a
++sequence number:
++
++    $ cat /sys/class/pps/pps0/assert
++    1170026870.983207967#8
++
++Where before the "#" is the timestamp in seconds and after it is the
++sequence number. Other files are:
++
++* echo: reports if the PPS source has an echo function or not;
++
++* mode: reports available PPS functioning modes;
++
++* name: reports the PPS source's name;
++
++* path: reports the PPS source's device path, that is the device the
++  PPS source is connected to (if it exists).
++
++
++Testing the PPS support
++-----------------------
++
++In order to test the PPS support even without specific hardware you can use
++the ktimer driver (see the client subsection in the PPS configuration menu)
++and the userland tools provided into Documentaion/pps/ directory.
++
++Once you have enabled the compilation of ktimer just modprobe it (if
++not statically compiled):
++
++   # modprobe ktimer
++
++and the run ppstest as follow:
++
++   $ ./ppstest /dev/pps0
++   trying PPS source "/dev/pps1"
++   found PPS source "/dev/pps1"
++   ok, found 1 source(s), now start fetching data...
++   source 0 - assert 1186592699.388832443, sequence: 364 - clear  0.000000000, sequence: 0
++   source 0 - assert 1186592700.388931295, sequence: 365 - clear  0.000000000, sequence: 0
++   source 0 - assert 1186592701.389032765, sequence: 366 - clear  0.000000000, sequence: 0
++
++Please, note that to compile userland programs you need the file timepps.h
++(see Documentation/pps/).
+diff --git a/Documentation/pps/ppsctl.c b/Documentation/pps/ppsctl.c
+new file mode 100644
+index 0000000..83fd08a
+--- /dev/null
++++ b/Documentation/pps/ppsctl.c
+@@ -0,0 +1,62 @@
++#include <stdio.h>
++#include <unistd.h>
++#include <stdlib.h>
++#include <errno.h>
++#include <sys/ioctl.h>
++#include <sys/types.h>
++#include <sys/stat.h>
++#include <fcntl.h>
++#include <string.h>
++#include <linux/serial.h>
++
++void usage(char *name)
++{
++	fprintf(stderr, "usage: %s <ttyS> [enable|disable]\n", name);
++
++	exit(EXIT_FAILURE);
++}
++
++int main(int argc, char *argv[])
++{
++	int fd;
++	int ret;
++	struct serial_struct ss;
++
++	if (argc < 2)
++		usage(argv[0]);
++
++	fd = open(argv[1], O_RDWR);
++	if (fd < 0) {
++		perror("open");
++		exit(EXIT_FAILURE);
++	}
++
++	ret = ioctl(fd, TIOCGSERIAL, &ss);
++	if (ret < 0) {
++		perror("ioctl(TIOCGSERIAL)");
++		exit(EXIT_FAILURE);
++	}
++
++	if (argc < 3) {		/* just read PPS status */
++		printf("PPS is %sabled\n",
++		       ss.flags & ASYNC_HARDPPS_CD ? "en" : "dis");
++		exit(EXIT_SUCCESS);
++	}
++
++	if (argv[2][0] == 'e' || argv[2][0] == '1')
++		ss.flags |= ASYNC_HARDPPS_CD;
++	else if (argv[2][0] == 'd' || argv[2][0] == '0')
++		ss.flags &= ~ASYNC_HARDPPS_CD;
++	else {
++		fprintf(stderr, "invalid state argument \"%s\"\n", argv[2]);
++		exit(EXIT_FAILURE);
++	}
++
++	ret = ioctl(fd, TIOCSSERIAL, &ss);
++	if (ret < 0) {
++		perror("ioctl(TIOCSSERIAL)");
++		exit(EXIT_FAILURE);
++	}
++
++	return 0;
++}
+diff --git a/Documentation/pps/ppsfind b/Documentation/pps/ppsfind
+new file mode 100755
+index 0000000..93c0e17
+--- /dev/null
++++ b/Documentation/pps/ppsfind
+@@ -0,0 +1,17 @@
++#!/bin/sh
++
++SYS="/sys/class/pps/"
++
++if [ $# -lt 1 ] ; then
++	echo "usage: ppsfind <name>" >&2
++	exit 1
++fi
++
++for d in $(ls $SYS) ; do
++	if grep $1 $SYS/$d/name >& /dev/null || \
++	   grep $1 $SYS/$d/path >& /dev/null ; then
++		echo "$d: name=$(cat $SYS/$d/name) path=$(cat $SYS/$d/path)"
++	fi
++done
++
++exit 0
+diff --git a/Documentation/pps/ppstest.c b/Documentation/pps/ppstest.c
+new file mode 100644
+index 0000000..d125ffa
+--- /dev/null
++++ b/Documentation/pps/ppstest.c
+@@ -0,0 +1,151 @@
++#include <stdio.h>
++#include <stdlib.h>
++#include <unistd.h>
++#include <errno.h>
++#include <string.h>
++#include <sys/types.h>
++#include <sys/stat.h>
++#include <fcntl.h>
++
++#include <timepps.h>
++
++int find_source(char *path, pps_handle_t *handle, int *avail_mode)
++{
++	pps_params_t params;
++	int ret;
++
++	printf("trying PPS source \"%s\"\n", path);
++
++	/* Try to find the source by using the supplied "path" name */
++	ret = open(path, O_RDWR);
++	if (ret < 0) {
++		fprintf(stderr, "unable to open device \"%s\" (%m)\n", path);
++		return ret;
++	}
++
++	/* Open the PPS source (and check the file descriptor) */
++	ret = time_pps_create(ret, handle);
++	if (ret < 0) {
++		fprintf(stderr, "cannot create a PPS source from device "
++				"\"%s\" (%m)\n", path);
++		return -1;
++	}
++	printf("found PPS source \"%s\"\n", path);
++
++	/* Find out what features are supported */
++	ret = time_pps_getcap(*handle, avail_mode);
++	if (ret < 0) {
++		fprintf(stderr, "cannot get capabilities (%m)\n");
++		return -1;
++	}
++	if ((*avail_mode & PPS_CAPTUREASSERT) == 0) {
++		fprintf(stderr, "cannot CAPTUREASSERT\n");
++		return -1;
++	}
++	if ((*avail_mode & PPS_OFFSETASSERT) == 0) {
++		fprintf(stderr, "cannot OFFSETASSERT\n");
++		return -1;
++	}
++
++	/* Capture assert timestamps, and compensate for a 675 nsec
++	 * propagation delay */
++	ret = time_pps_getparams(*handle, &params);
++	if (ret < 0) {
++		fprintf(stderr, "cannot get parameters (%m)\n");
++		return -1;
++	}
++	params.assert_offset.tv_sec = 0;
++	params.assert_offset.tv_nsec = 675;
++	params.mode |= PPS_CAPTUREASSERT | PPS_OFFSETASSERT;
++	ret = time_pps_setparams(*handle, &params);
++	if (ret < 0) {
++		fprintf(stderr, "cannot set parameters (%m)\n");
++		return -1;
++	}
++
++	return 0;
++}
++
++int fetch_source(int i, pps_handle_t *handle, int *avail_mode)
++{
++	struct timespec timeout;
++	pps_info_t infobuf;
++	int ret;
++
++	/* create a zero-valued timeout */
++	timeout.tv_sec = 3;
++	timeout.tv_nsec = 0;
++
++retry:
++	if (*avail_mode & PPS_CANWAIT) /* waits for the next event */
++		ret = time_pps_fetch(*handle, PPS_TSFMT_TSPEC, &infobuf,
++				   &timeout);
++	else {
++		sleep(1);
++		ret = time_pps_fetch(*handle, PPS_TSFMT_TSPEC, &infobuf,
++				   &timeout);
++	}
++	if (ret < 0) {
++		if (ret == -EINTR) {
++			fprintf(stderr, "time_pps_fetch() got a signal!\n");
++			goto retry;
++		}
++
++		fprintf(stderr, "time_pps_fetch() error %d (%m)\n", ret);
++		return -1;
++	}
++
++	printf("source %d - "
++	       "assert %ld.%09ld, sequence: %ld - "
++	       "clear  %ld.%09ld, sequence: %ld\n",
++	       i,
++	       infobuf.assert_timestamp.tv_sec,
++	       infobuf.assert_timestamp.tv_nsec,
++	       infobuf.assert_sequence,
++	       infobuf.clear_timestamp.tv_sec,
++	       infobuf.clear_timestamp.tv_nsec, infobuf.clear_sequence);
++
++	return 0;
++}
++
++void usage(char *name)
++{
++	fprintf(stderr, "usage: %s <ppsdev> [<ppsdev> ...]\n", name);
++	exit(EXIT_FAILURE);
++}
++
++int main(int argc, char *argv[])
++{
++	int num;
++	pps_handle_t handle[4];
++	int avail_mode[4];
++	int i = 0;
++	int ret;
++
++	/* Check the command line */
++	if (argc < 2)
++		usage(argv[0]);
++
++	for (i = 1; i < argc && i <= 4; i++) {
++		ret = find_source(argv[i], &handle[i - 1], &avail_mode[i - 1]);
++		if (ret < 0)
++			exit(EXIT_FAILURE);
++	}
++
++	num = i - 1;
++	printf("ok, found %d source(s), now start fetching data...\n", num);
++
++	/* loop, printing the most recent timestamp every second or so */
++	while (1) {
++		for (i = 0; i < num; i++) {
++			ret = fetch_source(i, &handle[i], &avail_mode[i]);
++			if (ret < 0 && errno != ETIMEDOUT)
++				exit(EXIT_FAILURE);
++		}
++	}
++
++	for (; i >= 0; i--)
++		time_pps_destroy(handle[i]);
++
++	return 0;
++}
+diff --git a/Documentation/pps/timepps.h b/Documentation/pps/timepps.h
+new file mode 100644
+index 0000000..28ebf4c
+--- /dev/null
++++ b/Documentation/pps/timepps.h
+@@ -0,0 +1,193 @@
++/*
++ * timepps.h -- PPS API main header
++ *
++ * Copyright (C) 2005-2007   Rodolfo Giometti <[email protected]>
++ *
++ *   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.
++ */
++
++#ifndef _SYS_TIMEPPS_H_
++#define _SYS_TIMEPPS_H_
++
++#include <sys/syscall.h>
++#include <unistd.h>
++#include <errno.h>
++#include <linux/pps.h>
++
++/*
++ * New data structures
++ */
++
++struct ntp_fp {
++	unsigned int integral;
++	unsigned int fractional;
++};
++
++union pps_timeu {
++	struct timespec tspec;
++	struct ntp_fp ntpfp;
++	unsigned long longpad[3];
++};
++
++struct pps_info {
++	unsigned long assert_sequence;	/* seq. num. of assert event */
++	unsigned long clear_sequence;	/* seq. num. of clear event */
++	union pps_timeu assert_tu;	/* time of assert event */
++	union pps_timeu clear_tu;	/* time of clear event */
++	int current_mode;		/* current mode bits */
++};
++
++struct pps_params {
++	int api_version;		/* API version # */
++	int mode;			/* mode bits */
++	union pps_timeu assert_off_tu;	/* offset compensation for assert */
++	union pps_timeu clear_off_tu;	/* offset compensation for clear */
++};
++
++typedef int pps_handle_t;		/* represents a PPS source */
++typedef unsigned long pps_seq_t;	/* sequence number */
++typedef struct ntp_fp ntp_fp_t;		/* NTP-compatible time stamp */
++typedef union pps_timeu pps_timeu_t;	/* generic data type for time stamps */
++typedef struct pps_info pps_info_t;
++typedef struct pps_params pps_params_t;
++
++#define assert_timestamp        assert_tu.tspec
++#define clear_timestamp         clear_tu.tspec
++
++#define assert_timestamp_ntpfp  assert_tu.ntpfp
++#define clear_timestamp_ntpfp   clear_tu.ntpfp
++
++#define assert_offset		assert_off_tu.tspec
++#define clear_offset		clear_off_tu.tspec
++
++#define assert_offset_ntpfp     assert_off_tu.ntpfp
++#define clear_offset_ntpfp      clear_off_tu.ntpfp
++
++/*
++ * The PPS API
++ */
++
++static __inline int time_pps_create(int source, pps_handle_t *handle)
++{
++	int ret;
++
++	if (!handle) {
++		errno = EINVAL;
++		return -1;
++	}
++
++	/* First we check if current device is a PPS valid PPS one...
++	 */
++	ret = ioctl(source, PPS_CHECK);
++	if (ret) {
++		errno = EOPNOTSUPP;
++		return -1;
++	}
++
++	/* ... then since in LinuxPPS there are no differences between a
++	 * "PPS source" and a "PPS handle", we simply return the same value.
++	 */
++	*handle = source;
++
++	return 0;
++}
++
++static __inline int time_pps_destroy(pps_handle_t handle)
++{
++	return close(handle);
++}
++
++static __inline int time_pps_getparams(pps_handle_t handle,
++					pps_params_t *ppsparams)
++{
++	int ret;
++	struct pps_kparams __ppsparams;
++
++	ret = ioctl(handle, PPS_GETPARAMS, &__ppsparams);
++
++	ppsparams->api_version = __ppsparams.api_version;
++	ppsparams->mode = __ppsparams.mode;
++	ppsparams->assert_off_tu.tspec.tv_sec = __ppsparams.assert_off_tu.sec;
++	ppsparams->assert_off_tu.tspec.tv_nsec = __ppsparams.assert_off_tu.nsec;
++	ppsparams->clear_off_tu.tspec.tv_sec = __ppsparams.clear_off_tu.sec;
++	ppsparams->clear_off_tu.tspec.tv_nsec = __ppsparams.clear_off_tu.nsec;
++
++	return ret;
++}
++
++static __inline int time_pps_setparams(pps_handle_t handle,
++					const pps_params_t *ppsparams)
++{
++	struct pps_kparams __ppsparams;
++
++	__ppsparams.api_version = ppsparams->api_version;
++	__ppsparams.mode = ppsparams->mode;
++	__ppsparams.assert_off_tu.sec = ppsparams->assert_off_tu.tspec.tv_sec;
++	__ppsparams.assert_off_tu.nsec = ppsparams->assert_off_tu.tspec.tv_nsec;
++	__ppsparams.clear_off_tu.sec = ppsparams->clear_off_tu.tspec.tv_sec;
++	__ppsparams.clear_off_tu.nsec = ppsparams->clear_off_tu.tspec.tv_nsec;
++
++	return ioctl(handle, PPS_SETPARAMS, &__ppsparams);
++}
++
++/* Get capabilities for handle */
++static __inline int time_pps_getcap(pps_handle_t handle, int *mode)
++{
++	return ioctl(handle, PPS_GETCAP, mode);
++}
++
++static __inline int time_pps_fetch(pps_handle_t handle, const int tsformat,
++					pps_info_t *ppsinfobuf,
++					const struct timespec *timeout)
++{
++	struct pps_fdata __fdata;
++	int ret;
++
++	/* Sanity checks */
++	if (tsformat != PPS_TSFMT_TSPEC) {
++		errno = EINVAL;
++		return -1;
++	}
++
++	if (timeout) {
++		__fdata.timeout.sec = timeout->tv_sec;
++		__fdata.timeout.nsec = timeout->tv_nsec;
++		__fdata.timeout.flags = ~PPS_TIME_INVALID;
++	} else
++		__fdata.timeout.flags = PPS_TIME_INVALID;
++
++	ret = ioctl(handle, PPS_FETCH, &__fdata);
++
++	ppsinfobuf->assert_sequence = __fdata.info.assert_sequence;
++	ppsinfobuf->clear_sequence = __fdata.info.clear_sequence;
++	ppsinfobuf->assert_tu.tspec.tv_sec = __fdata.info.assert_tu.sec;
++	ppsinfobuf->assert_tu.tspec.tv_nsec = __fdata.info.assert_tu.nsec;
++	ppsinfobuf->clear_tu.tspec.tv_sec = __fdata.info.clear_tu.sec;
++	ppsinfobuf->clear_tu.tspec.tv_nsec = __fdata.info.clear_tu.nsec;
++	ppsinfobuf->current_mode = __fdata.info.current_mode;
++
++	return ret;
++}
++
++static __inline int time_pps_kcbind(pps_handle_t handle,
++					const int kernel_consumer,
++					const int edge, const int tsformat)
++{
++	/* LinuxPPS doesn't implement kernel consumer feature */
++	errno = EOPNOTSUPP;
++	return -1;
++}
++
++#endif				/* _SYS_TIMEPPS_H_ */
+diff --git a/MAINTAINERS b/MAINTAINERS
+index 9a91d9e..f45e974 100644
+--- a/MAINTAINERS
++++ b/MAINTAINERS
+@@ -3011,6 +3011,13 @@ P:	James Chapman
+ M:	[email protected]
+ S:	Maintained
+ 
++PPS SUPPORT
++P:	Rodolfo Giometti
++M:	[email protected]
++W:	http://wiki.enneenne.com/index.php/LinuxPPS_support
++L:	[email protected]
++S:	Maintained
++
+ PREEMPTIBLE KERNEL
+ P:	Robert Love
+ M:	[email protected]
+diff --git a/drivers/Kconfig b/drivers/Kconfig
+index 3e1c442..bffc48e 100644
+--- a/drivers/Kconfig
++++ b/drivers/Kconfig
+@@ -52,6 +52,8 @@ source "drivers/i2c/Kconfig"
+ 
+ source "drivers/spi/Kconfig"
+ 
++source "drivers/pps/Kconfig"
++
+ source "drivers/w1/Kconfig"
+ 
+ source "drivers/power/Kconfig"
+diff --git a/drivers/Makefile b/drivers/Makefile
+index f0878b2..2e84e49 100644
+--- a/drivers/Makefile
++++ b/drivers/Makefile
+@@ -63,6 +63,7 @@ obj-$(CONFIG_INPUT)		+= input/
+ obj-$(CONFIG_I2O)		+= message/
+ obj-$(CONFIG_RTC_LIB)		+= rtc/
+ obj-y				+= i2c/
++obj-$(CONFIG_PPS)		+= pps/
+ obj-$(CONFIG_W1)		+= w1/
+ obj-$(CONFIG_POWER_SUPPLY)	+= power/
+ obj-$(CONFIG_HWMON)		+= hwmon/
+diff --git a/drivers/char/lp.c b/drivers/char/lp.c
+index 62051f8..e0a8364 100644
+--- a/drivers/char/lp.c
++++ b/drivers/char/lp.c
+@@ -746,6 +746,27 @@ static struct console lpcons = {
+ 
+ #endif /* console on line printer */
+ 
++/* Support for PPS signal on the line printer */
++
++#ifdef CONFIG_PPS_CLIENT_LP
++
++static void lp_pps_echo(int source, int event, void *data)
++{
++	struct parport *port = data;
++	unsigned char status = parport_read_status(port);
++
++	/* echo event via SEL bit */
++	parport_write_control(port,
++		parport_read_control(port) | PARPORT_CONTROL_SELECT);
++
++	/* signal no event */
++	if ((status & PARPORT_STATUS_ACK) != 0)
++		parport_write_control(port,
++			parport_read_control(port) & ~PARPORT_CONTROL_SELECT);
++}
++
++#endif
++
+ /* --- initialisation code ------------------------------------- */
+ 
+ static int parport_nr[LP_NO] = { [0 ... LP_NO-1] = LP_PARPORT_UNSPEC };
+@@ -817,6 +838,38 @@ static int lp_register(int nr, struct parport *port)
+ 	}
+ #endif
+ 
++#ifdef CONFIG_PPS_CLIENT_LP
++	port->pps_info.owner = THIS_MODULE;
++	port->pps_info.dev = port->dev;
++	snprintf(port->pps_info.path, PPS_MAX_NAME_LEN, "/dev/lp%d", nr);
++
++	/* No PPS support if lp port has no IRQ line */
++	if (port->irq != PARPORT_IRQ_NONE) {
++		strncpy(port->pps_info.name, port->name, PPS_MAX_NAME_LEN);
++
++		port->pps_info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
++				PPS_ECHOASSERT | \
++				PPS_CANWAIT | PPS_TSFMT_TSPEC;
++
++		port->pps_info.echo = lp_pps_echo;
++
++		port->pps_source = pps_register_source(&(port->pps_info),
++				PPS_CAPTUREASSERT | PPS_OFFSETASSERT);
++		if (port->pps_source < 0)
++			dev_err(port->dev,
++					"cannot register PPS source \"%s\"\n",
++					port->pps_info.path);
++		else
++			dev_info(port->dev, "PPS source #%d \"%s\" added\n",
++					port->pps_source, port->pps_info.path);
++	} else {
++		port->pps_source = -1;
++		dev_err(port->dev, "PPS support disabled due port \"%s\" is "
++					"in polling mode\n",
++					port->pps_info.path);
++	}
++#endif
++
+ 	return 0;
+ }
+ 
+@@ -860,6 +913,14 @@ static void lp_detach (struct parport *port)
+ 		console_registered = NULL;
+ 	}
+ #endif /* CONFIG_LP_CONSOLE */
++
++#ifdef CONFIG_PPS_CLIENT_LP
++	if (port->pps_source >= 0) {
++		pps_unregister_source(port->pps_source);
++		dev_dbg(port->dev, "PPS source #%d \"%s\" removed\n",
++			port->pps_source, port->pps_info.path);
++	}
++#endif
+ }
+ 
+ static struct parport_driver lp_driver = {
+diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig
+new file mode 100644
+index 0000000..bfe6621
+--- /dev/null
++++ b/drivers/pps/Kconfig
+@@ -0,0 +1,34 @@
++#
++# PPS support configuration
++#
++
++menu "PPS support"
++
++config PPS
++	tristate "PPS support"
++	depends on EXPERIMENTAL
++	---help---
++	  PPS (Pulse Per Second) is a special pulse provided by some GPS
++	  antennae. Userland can use it to get an high time reference.
++
++	  Some antennae's PPS signals are connected with the CD (Carrier
++	  Detect) pin of the serial line they use to communicate with the
++	  host. In this case use the SERIAL_LINE client support.
++
++	  Some antennae's PPS signals are connected with some special host
++	  inputs so you have to enable the corresponding client support.
++
++	  To compile this driver as a module, choose M here: the module
++	  will be called pps_core.ko.
++
++config PPS_DEBUG
++	bool "PPS debugging messages"
++	depends on PPS 
++	help
++	  Say Y here if you want the PPS support to produce a bunch of debug
++	  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.
++
++source drivers/pps/clients/Kconfig
++
++endmenu
+diff --git a/drivers/pps/Makefile b/drivers/pps/Makefile
+new file mode 100644
+index 0000000..d8ec308
+--- /dev/null
++++ b/drivers/pps/Makefile
+@@ -0,0 +1,11 @@
++#
++# Makefile for the PPS core.
++#
++
++pps_core-objs			+= pps.o kapi.o sysfs.o
++obj-$(CONFIG_PPS)		+= pps_core.o
++obj-y				+= clients/
++
++ifeq ($(CONFIG_PPS_DEBUG),y)
++EXTRA_CFLAGS += -DDEBUG
++endif
+diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
+new file mode 100644
+index 0000000..09ba5c3
+--- /dev/null
++++ b/drivers/pps/clients/Kconfig
+@@ -0,0 +1,38 @@
++#
++# PPS clients configuration
++#
++
++if PPS
++
++comment "PPS clients support"
++
++config PPS_CLIENT_KTIMER
++	tristate "Kernel timer client (Testing client, use for debug)"
++	help
++	  If you say yes here you get support for a PPS debugging client
++	  which uses a kernel timer to generate the PPS signal.
++
++	  This driver can also be built as a module.  If so, the module
++	  will be called ktimer.ko.
++
++comment "UART serial support (forced off)"
++	depends on ! (SERIAL_CORE != n && !(PPS = m && SERIAL_CORE = y))
++
++config PPS_CLIENT_UART
++	bool "UART serial support"
++	depends on SERIAL_CORE != n && !(PPS = m && SERIAL_CORE = y)
++	help
++	  If you say yes here you get support for a PPS source connected
++	  with the CD (Carrier Detect) pin of your serial port.
++
++comment "Parallel printer support (forced off)"
++	depends on !( PRINTER != n && !(PPS = m && PRINTER = y))
++
++config PPS_CLIENT_LP
++	bool "Parallel printer support"
++	depends on PRINTER != n && !(PPS = m && PRINTER = y)
++	help
++	  If you say yes here you get support for a PPS source connected
++	  with the interrupt pin of your parallel port.
++
++endif
+diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
+new file mode 100644
+index 0000000..f3c1e39
+--- /dev/null
++++ b/drivers/pps/clients/Makefile
+@@ -0,0 +1,9 @@
++#
++# Makefile for PPS clients.
++#
++
++obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= ktimer.o
++
++ifeq ($(CONFIG_PPS_DEBUG),y)
++EXTRA_CFLAGS += -DDEBUG
++endif
+diff --git a/drivers/pps/clients/ktimer.c b/drivers/pps/clients/ktimer.c
+new file mode 100644
+index 0000000..4d613ab
+--- /dev/null
++++ b/drivers/pps/clients/ktimer.c
+@@ -0,0 +1,114 @@
++/*
++ * ktimer.c -- kernel timer test client
++ *
++ *
++ * Copyright (C) 2005-2006   Rodolfo Giometti <[email protected]>
++ *
++ *   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.h>
++
++/*
++ * Global variables
++ */
++
++static int source;
++static struct timer_list ktimer;
++
++/*
++ * The kernel timer
++ */
++
++static void pps_ktimer_event(unsigned long ptr)
++{
++	pr_info("PPS event at %lu\n", jiffies);
++
++	pps_event(source, 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 <[email protected]>");
++MODULE_DESCRIPTION("dummy PPS source by using a kernel timer (just for debug)");
++MODULE_LICENSE("GPL");
+diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
+new file mode 100644
+index 0000000..67290d5
+--- /dev/null
++++ b/drivers/pps/kapi.c
+@@ -0,0 +1,271 @@
++/*
++ * kapi.c -- kernel API
++ *
++ *
++ * Copyright (C) 2005-2007   Rodolfo Giometti <[email protected]>
++ *
++ *   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/sched.h>
++#include <linux/time.h>
++#include <linux/spinlock.h>
++#include <linux/idr.h>
++#include <linux/fs.h>
++#include <linux/pps.h>
++
++/*
++ * Local variables
++ */
++
++static spinlock_t idr_lock = SPIN_LOCK_UNLOCKED;
++static DEFINE_IDR(pps_idr);
++
++/*
++ * Local functions
++ */
++
++static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
++{
++	ts->nsec += offset->nsec;
++	if (ts->nsec >= NSEC_PER_SEC) {
++		ts->nsec -= NSEC_PER_SEC;
++		ts->sec++;
++	} else if (ts->nsec < 0) {
++		ts->nsec += NSEC_PER_SEC;
++		ts->sec--;
++	}
++	ts->sec += offset->sec;
++}
++
++/*
++ * Exported functions
++ */
++
++int pps_register_source(struct pps_source_info *info, int default_params)
++{
++	struct pps_device *pps;
++	int id;
++	int err;
++
++	/* Sanity checks */
++	if ((info->mode & default_params) != default_params) {
++		printk(KERN_ERR "pps: %s: unsupported default parameters\n",
++					info->name);
++		err = -EINVAL;
++		goto pps_register_source_exit;
++	}
++	if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 &&
++			info->echo == NULL) {
++		printk(KERN_ERR "pps: %s: echo function is not defined\n",
++					info->name);
++		err = -EINVAL;
++		goto pps_register_source_exit;
++	}
++	if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
++		printk(KERN_ERR "pps: %s: unspecified time format\n",
++					info->name);
++		err = -EINVAL;
++		goto pps_register_source_exit;
++	}
++
++	/* Allocate memory for the new PPS source struct */
++	pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
++	if (pps == NULL) {
++		err = -ENOMEM;
++		goto pps_register_source_exit;
++	}
++
++	/* Get new ID for the new PPS source */
++	if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) {
++		err = -ENOMEM;
++		goto kfree_pps;
++	}
++
++	spin_lock_irq(&idr_lock);
++	err = idr_get_new(&pps_idr, pps, &id);
++	spin_unlock_irq(&idr_lock);
++
++	if (err < 0)
++		goto kfree_pps;
++
++	id = id & MAX_ID_MASK;
++	if (id >= PPS_MAX_SOURCES) {
++		printk(KERN_ERR "pps: %s: too much PPS sources in the system\n",
++					info->name);
++		err = -EBUSY;
++		goto free_idr;
++	}
++
++	pps->id = id;
++	pps->params.api_version = PPS_API_VERS;
++	pps->params.mode = default_params;
++	pps->info = *info;
++
++	init_waitqueue_head(&pps->queue);
++	spin_lock_init(&pps->lock);
++	atomic_set(&pps->usage, 0);
++	init_waitqueue_head(&pps->usage_queue);
++
++	/* Create the char device */
++	err = pps_register_cdev(pps);
++	if (err < 0) {
++		printk(KERN_ERR "pps: %s: unable to create char device\n",
++					info->name);
++		goto free_idr;
++	}
++
++	/* Create the sysfs entry */
++	err = pps_sysfs_create_source_entry(pps);
++	if (err < 0) {
++		printk(KERN_ERR "pps: %s: unable to create sysfs entries\n",
++					info->name);
++		goto unregister_cdev;
++	}
++
++	pr_info("new PPS source %s at ID %d\n", info->name, id);
++
++	return id;
++
++unregister_cdev:
++	pps_unregister_cdev(pps);
++
++free_idr:
++	spin_lock_irq(&idr_lock);
++	idr_remove(&pps_idr, id);
++	spin_unlock_irq(&idr_lock);
++
++kfree_pps:
++	kfree(pps);
++
++pps_register_source_exit:
++	printk(KERN_ERR "pps: %s: unable to register source\n", info->name);
++
++	return err;
++}
++EXPORT_SYMBOL(pps_register_source);
++
++void pps_unregister_source(int source)
++{
++	struct pps_device *pps;
++
++	spin_lock_irq(&idr_lock);
++	pps = idr_find(&pps_idr, source);
++
++	if (!pps) {
++		spin_unlock_irq(&idr_lock);
++		return;
++	}
++
++	/* This should be done first in order to deny IRQ handlers
++	 * to access PPS structs
++	 */
++
++	idr_remove(&pps_idr, pps->id);
++	spin_unlock_irq(&idr_lock);
++
++	wait_event(pps->usage_queue, atomic_read(&pps->usage) == 0);
++
++	pps_sysfs_remove_source_entry(pps);
++	pps_unregister_cdev(pps);
++	kfree(pps);
++}
++EXPORT_SYMBOL(pps_unregister_source);
++
++void pps_event(int source, int event, void *data)
++{
++	struct pps_device *pps;
++	struct timespec __ts;
++	struct pps_ktime ts;
++	unsigned long flags;
++
++	/* First of all we get the time stamp... */
++	getnstimeofday(&__ts);
++
++	/* ... and translate it to PPS time data struct */
++	ts.sec = __ts.tv_sec;
++	ts.nsec = __ts.tv_nsec;
++
++	if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0 ) {
++		printk(KERN_ERR "pps: unknown event (%x) for source %d\n",
++			event, source);
++		return;
++	}
++
++	spin_lock_irqsave(&idr_lock, flags);
++	pps = idr_find(&pps_idr, source);
++
++	/* If we find a valid PPS source we lock it before leaving
++	 * the lock!
++	 */
++	if (pps)
++		atomic_inc(&pps->usage);
++	spin_unlock_irqrestore(&idr_lock, flags);
++
++	if (!pps)
++		return;
++
++	pr_debug("PPS event on source %d at at %llu.%06u\n",
++			pps->id, ts.sec, ts.nsec);
++
++	spin_lock_irqsave(&pps->lock, flags);
++
++	/* Must call the echo function? */
++	if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
++		pps->info.echo(source, event, data);
++
++	/* Check the event */
++	pps->current_mode = pps->params.mode;
++	if (event & PPS_CAPTUREASSERT) {
++		/* We have to add an offset? */
++		if (pps->params.mode & PPS_OFFSETASSERT)
++			pps_add_offset(&ts, &pps->params.assert_off_tu);
++
++		/* Save the time stamp */
++		pps->assert_tu = ts;
++		pps->assert_sequence++;
++		pr_debug("capture assert seq #%u for source %d\n",
++			pps->assert_sequence, source);
++	}
++	if (event & PPS_CAPTURECLEAR) {
++		/* We have to add an offset? */
++		if (pps->params.mode & PPS_OFFSETCLEAR)
++			pps_add_offset(&ts, &pps->params.clear_off_tu);
++
++		/* Save the time stamp */
++		pps->clear_tu = ts;
++		pps->clear_sequence++;
++		pr_debug("capture clear seq #%u for source %d\n",
++			pps->clear_sequence, source);
++	}
++
++	pps->go = ~0;
++	wake_up_interruptible(&pps->queue);
++
++	kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
++
++	spin_unlock_irqrestore(&pps->lock, flags);
++
++	/* Now we can release the PPS source for (possible) deregistration */
++	spin_lock_irqsave(&idr_lock, flags);
++	atomic_dec(&pps->usage);
++	wake_up_all(&pps->usage_queue);
++	spin_unlock_irqrestore(&idr_lock, flags);
++}
++EXPORT_SYMBOL(pps_event);
+diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
+new file mode 100644
+index 0000000..52de2f1
+--- /dev/null
++++ b/drivers/pps/pps.c
+@@ -0,0 +1,332 @@
++/*
++ * pps.c -- Main PPS support file
++ *
++ *
++ * Copyright (C) 2005-2007   Rodolfo Giometti <[email protected]>
++ *
++ *   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/version.h>
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/sched.h>
++#include <linux/uaccess.h>
++#include <linux/cdev.h>
++#include <linux/poll.h>
++#include <linux/pps.h>
++
++/*
++ * Local variables
++ */
++
++static dev_t pps_devt;
++static struct class *pps_class;
++
++/*
++ * Char device methods
++ */
++
++static unsigned int pps_cdev_poll(struct file *file, poll_table *wait)
++{
++	struct pps_device *pps = file->private_data;
++
++	poll_wait(file, &pps->queue, wait);
++
++	return POLLIN | POLLRDNORM;
++}
++
++static int pps_cdev_fasync(int fd, struct file *file, int on)
++{
++	struct pps_device *pps = file->private_data;
++	return fasync_helper(fd, file, on, &pps->async_queue);
++}
++
++static int pps_cdev_ioctl(struct inode *inode, struct file *file,
++		unsigned int cmd, unsigned long arg)
++{
++	struct pps_device *pps = file->private_data;
++	struct pps_kparams params;
++	struct pps_fdata fdata;
++	unsigned long ticks;
++	void __user *uarg = (void __user *) arg;
++	int __user *iuarg = (int __user *) arg;
++	int err;
++
++	switch (cmd) {
++	case PPS_CHECK:
++
++		/* This does nothing but signal we are a PPS source... */
++
++		return 0;
++
++	case PPS_GETPARAMS:
++		pr_debug("PPS_GETPARAMS: source %d\n", pps->id);
++
++		/* Sanity checks */
++		if (!uarg)
++			return -EINVAL;
++
++		/* Return current parameters */
++		err = copy_to_user(uarg, &pps->params,
++						sizeof(struct pps_kparams));
++		if (err)
++			return -EFAULT;
++
++		break;
++
++	case PPS_SETPARAMS:
++		pr_debug("PPS_SETPARAMS: source %d\n", pps->id);
++
++		/* Check the capabilities */
++		if (!capable(CAP_SYS_TIME))
++			return -EPERM;
++
++		/* Sanity checks */
++		if (!uarg)
++			return -EINVAL;
++		err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
++		if (err)
++			return -EFAULT;
++		if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
++			pr_debug("capture mode unspecified (%x)\n",
++								params.mode);
++			return -EINVAL;
++		}
++
++		/* Check for supported capabilities */
++		if ((params.mode & ~pps->info.mode) != 0) {
++			pr_debug("unsupported capabilities (%x)\n",
++								params.mode);
++			return -EINVAL;
++		}
++
++		spin_lock_irq(&pps->lock);
++
++		/* Save the new parameters */
++		pps->params = params;
++
++		/* Restore the read only parameters */
++		if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
++			/* section 3.3 of RFC 2783 interpreted */
++			pr_debug("time format unspecified (%x)\n",
++								params.mode);
++			pps->params.mode |= PPS_TSFMT_TSPEC;
++		}
++		if (pps->info.mode & PPS_CANWAIT)
++			pps->params.mode |= PPS_CANWAIT;
++		pps->params.api_version = PPS_API_VERS;
++
++		spin_unlock_irq(&pps->lock);
++
++		break;
++
++	case PPS_GETCAP:
++		pr_debug("PPS_GETCAP: source %d\n", pps->id);
++
++		/* Sanity checks */
++		if (!uarg)
++			return -EINVAL;
++
++		err = put_user(pps->info.mode, iuarg);
++		if (err)
++			return -EFAULT;
++
++		break;
++
++	case PPS_FETCH:
++		pr_debug("PPS_FETCH: source %d\n", pps->id);
++
++		if (!uarg)
++			return -EINVAL;
++		err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
++		if (err)
++			return -EFAULT;
++
++		pps->go = 0;
++
++		/* Manage the timeout */
++		if (fdata.timeout.flags & PPS_TIME_INVALID)
++			err = wait_event_interruptible(pps->queue, pps->go);
++		else {
++			pr_debug("timeout %lld.%09d\n",
++					fdata.timeout.sec, fdata.timeout.nsec);
++			ticks = fdata.timeout.sec * HZ;
++			ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
++
++			if (ticks != 0) {
++				err = wait_event_interruptible_timeout(
++						pps->queue, pps->go, ticks);
++				if (err == 0)
++					return -ETIMEDOUT;
++			}
++		}
++
++		/* Check for pending signals */
++		if (err == -ERESTARTSYS) {
++			pr_debug("pending signal caught\n");
++			return -EINTR;
++		}
++
++		/* Return the fetched timestamp */
++		spin_lock_irq(&pps->lock);
++
++		fdata.info.assert_sequence = pps->assert_sequence;
++		fdata.info.clear_sequence = pps->clear_sequence;
++		fdata.info.assert_tu = pps->assert_tu;
++		fdata.info.clear_tu = pps->clear_tu;
++		fdata.info.current_mode = pps->current_mode;
++
++		spin_unlock_irq(&pps->lock);
++
++		err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
++		if (err)
++			return -EFAULT;
++
++		break;
++
++	default:
++		return -ENOTTY;
++		break;
++	}
++
++	return 0;
++}
++
++static int pps_cdev_open(struct inode *inode, struct file *file)
++{
++	struct pps_device *pps = container_of(inode->i_cdev,
++						struct pps_device, cdev);
++
++	/* Lock the PPS source against (possible) deregistration */
++	atomic_inc(&pps->usage);
++
++	file->private_data = pps;
++
++	return 0;
++}
++
++static int pps_cdev_release(struct inode *inode, struct file *file)
++{
++	struct pps_device *pps = file->private_data;
++
++	/* Free the PPS source and wake up (possible) deregistration */
++	atomic_dec(&pps->usage);
++	wake_up_all(&pps->usage_queue);
++
++	return 0;
++}
++
++/*
++ * Char device stuff
++ */
++
++static const struct file_operations pps_cdev_fops = {
++	.owner		= THIS_MODULE,
++	.llseek		= no_llseek,
++	.poll		= pps_cdev_poll,
++	.fasync		= pps_cdev_fasync,
++	.ioctl		= pps_cdev_ioctl,
++	.open		= pps_cdev_open,
++	.release	= pps_cdev_release,
++};
++
++int pps_register_cdev(struct pps_device *pps)
++{
++	int err;
++
++	pps->devno = MKDEV(MAJOR(pps_devt), pps->id);
++	cdev_init(&pps->cdev, &pps_cdev_fops);
++	pps->cdev.owner = pps->info.owner;
++
++	err = cdev_add(&pps->cdev, pps->devno, 1);
++	if (err) {
++		printk(KERN_ERR "pps: %s: failed to add char device %d:%d\n",
++				pps->info.name, MAJOR(pps_devt), pps->id);
++		return err;
++	}
++	pps->dev = device_create(pps_class, pps->info.dev, pps->devno,
++							"pps%d", pps->id);
++	if (err)
++		goto del_cdev;
++	dev_set_drvdata(pps->dev, pps);
++
++	pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
++			MAJOR(pps_devt), pps->id);
++
++	return 0;
++
++del_cdev:
++	cdev_del(&pps->cdev);
++
++	return err;
++}
++
++void pps_unregister_cdev(struct pps_device *pps)
++{
++	device_destroy(pps_class, pps->devno);
++	cdev_del(&pps->cdev);
++}
++
++/*
++ * Module staff
++ */
++
++static void __exit pps_exit(void)
++{
++	class_destroy(pps_class);
++
++	if (pps_devt)
++		unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
++
++	pr_info("LinuxPPS API ver. %d removed\n", PPS_API_VERS);
++}
++
++static int __init pps_init(void)
++{
++	int err;
++
++	pps_class = class_create(THIS_MODULE, "pps");
++	if (!pps_class) {
++		printk(KERN_ERR "pps: ailed to allocate class\n");
++		return -ENOMEM;
++	}
++
++	err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
++	if (err < 0) {
++		printk(KERN_ERR "pps: failed to allocate char device region\n");
++		goto remove_class;
++	}
++
++	pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
++	pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
++		"<[email protected]>\n", PPS_VERSION);
++
++	return 0;
++
++remove_class:
++	class_destroy(pps_class);
++
++	return err;
++}
++
++subsys_initcall(pps_init);
++module_exit(pps_exit);
++
++MODULE_AUTHOR("Rodolfo Giometti <[email protected]>");
++MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
++MODULE_LICENSE("GPL");
+diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c
+new file mode 100644
+index 0000000..8541be7
+--- /dev/null
++++ b/drivers/pps/sysfs.c
+@@ -0,0 +1,124 @@
++/*
++ * sysfs.c -- sysfs support
++ *
++ *
++ * Copyright (C) 2007   Rodolfo Giometti <[email protected]>
++ *
++ *   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/device.h>
++#include <linux/module.h>
++#include <linux/string.h>
++#include <linux/pps.h>
++
++/*
++ * Attribute functions
++ */
++
++static ssize_t pps_show_assert(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%lld.%09d#%d\n",
++			pps->assert_tu.sec, pps->assert_tu.nsec,
++			pps->assert_sequence);
++}
++DEVICE_ATTR(assert, S_IRUGO, pps_show_assert, NULL);
++
++static ssize_t pps_show_clear(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%lld.%09d#%d\n",
++			pps->clear_tu.sec, pps->clear_tu.nsec,
++			pps->clear_sequence);
++}
++DEVICE_ATTR(clear, S_IRUGO, pps_show_clear, NULL);
++
++static ssize_t pps_show_mode(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%4x\n", pps->info.mode);
++}
++DEVICE_ATTR(mode, S_IRUGO, pps_show_mode, NULL);
++
++static ssize_t pps_show_echo(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%d\n", !!pps->info.echo);
++}
++DEVICE_ATTR(echo, S_IRUGO, pps_show_echo, NULL);
++
++static ssize_t pps_show_name(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%s\n", pps->info.name);
++}
++DEVICE_ATTR(name, S_IRUGO, pps_show_name, NULL);
++
++static ssize_t pps_show_path(struct device *dev,
++				struct device_attribute *attr, char *buf)
++{
++	struct pps_device *pps = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%s\n", pps->info.path);
++}
++DEVICE_ATTR(path, S_IRUGO, pps_show_path, NULL);
++
++/*
++ * Public functions
++ */
++
++void pps_sysfs_remove_source_entry(struct pps_device *pps)
++{
++	/* Delete info files */
++	if (pps->info.mode & PPS_CAPTUREASSERT)
++		device_remove_file(pps->dev, &dev_attr_assert);
++
++	if (pps->info.mode & PPS_CAPTURECLEAR)
++		device_remove_file(pps->dev, &dev_attr_clear);
++
++	device_remove_file(pps->dev, &dev_attr_mode);
++	device_remove_file(pps->dev, &dev_attr_echo);
++	device_remove_file(pps->dev, &dev_attr_name);
++	device_remove_file(pps->dev, &dev_attr_path);
++}
++
++int pps_sysfs_create_source_entry(struct pps_device *pps)
++{
++	/* Create file "assert" and "clear" according to source capability */
++	if (pps->info.mode & PPS_CAPTUREASSERT)
++		device_create_file(pps->dev, &dev_attr_assert);
++
++	if (pps->info.mode & PPS_CAPTURECLEAR)
++		device_create_file(pps->dev, &dev_attr_clear);
++
++	device_create_file(pps->dev, &dev_attr_mode);
++	device_create_file(pps->dev, &dev_attr_echo);
++	device_create_file(pps->dev, &dev_attr_name);
++	device_create_file(pps->dev, &dev_attr_path);
++
++	return 0;
++}
+diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
+index f94109c..a5e83f8 100644
+--- a/drivers/serial/8250.c
++++ b/drivers/serial/8250.c
+@@ -2118,6 +2118,8 @@ serial8250_set_termios(struct uart_port *port, struct ktermios *termios,
+ 		up->ier |= UART_IER_MSI;
+ 	if (up->capabilities & UART_CAP_UUE)
+ 		up->ier |= UART_IER_UUE | UART_IER_RTOIE;
++	if (up->port.flags & UPF_HARDPPS_CD)
++		up->ier |= UART_IER_MSI;	/* enable interrupts */
+ 
+ 	serial_out(up, UART_IER, up->ier);
+ 
+diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
+index a055f58..a40b87c 100644
+--- a/drivers/serial/serial_core.c
++++ b/drivers/serial/serial_core.c
+@@ -33,6 +33,7 @@
+ #include <linux/serial.h> /* for serial_state and serial_icounter_struct */
+ #include <linux/delay.h>
+ #include <linux/mutex.h>
++#include <linux/pps.h>
+ 
+ #include <asm/irq.h>
+ #include <asm/uaccess.h>
+@@ -633,6 +634,54 @@ static int uart_get_info(struct uart_state *state,
+ 	return 0;
+ }
+ 
++#ifdef CONFIG_PPS_CLIENT_UART
++
++static int
++uart_register_pps_port(struct uart_state *state, struct uart_port *port)
++{
++	struct tty_driver *drv = port->info->tty->driver;
++	int ret;
++
++	state->pps_info.owner = THIS_MODULE;
++	state->pps_info.dev = port->dev;
++	snprintf(state->pps_info.name, PPS_MAX_NAME_LEN, "%s%d",
++		drv->driver_name, port->line);
++	snprintf(state->pps_info.path, PPS_MAX_NAME_LEN, "/dev/%s%d",
++		drv->name, port->line);
++
++	state->pps_info.mode = PPS_CAPTUREBOTH | \
++			PPS_OFFSETASSERT | PPS_OFFSETCLEAR | \
++			PPS_CANWAIT | PPS_TSFMT_TSPEC;
++
++	ret = pps_register_source(&state->pps_info, PPS_CAPTUREBOTH | \
++				PPS_OFFSETASSERT | PPS_OFFSETCLEAR);
++	if (ret < 0) {
++		dev_err(port->dev, "cannot register PPS source \"%s\"\n",
++						state->pps_info.path);
++		return ret;
++	}
++	port->pps_source = ret;
++	dev_dbg(port->dev, "PPS source #%d \"%s\" added\n",
++		port->pps_source, state->pps_info.path);
++
++	return 0;
++}
++
++static void
++uart_unregister_pps_port(struct uart_state *state, struct uart_port *port)
++{
++	pps_unregister_source(port->pps_source);
++	dev_dbg(port->dev, "PPS source #%d \"%s\" removed\n",
++				port->pps_source, state->pps_info.path);
++}
++
++#else
++
++#define uart_register_pps_port(state, port)	do { } while (0)
++#define uart_unregister_pps_port(state, port)	do { } while (0)
++
++#endif /* CONFIG_PPS_CLIENT_UART */
++
+ static int uart_set_info(struct uart_state *state,
+ 			 struct serial_struct __user *newinfo)
+ {
+@@ -807,11 +856,19 @@ static int uart_set_info(struct uart_state *state,
+ 			(port->flags & UPF_LOW_LATENCY) ? 1 : 0;
+ 
+  check_and_exit:
++	/* PPS support enabled/disabled? */
++	if ((old_flags & UPF_HARDPPS_CD) != (new_flags & UPF_HARDPPS_CD)) {
++		if (new_flags & UPF_HARDPPS_CD)
++			uart_register_pps_port(state, port);
++		else
++			uart_unregister_pps_port(state, port);
++	}
++
+ 	retval = 0;
+ 	if (port->type == PORT_UNKNOWN)
+ 		goto exit;
+ 	if (state->info->flags & UIF_INITIALIZED) {
+-		if (((old_flags ^ port->flags) & UPF_SPD_MASK) ||
++		if (((old_flags ^ port->flags) & (UPF_SPD_MASK|UPF_HARDPPS_CD)) ||
+ 		    old_custom_divisor != port->custom_divisor) {
+ 			/*
+ 			 * If they're setting up a custom divisor or speed,
+@@ -2110,6 +2167,12 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
+ 		port->ops->config_port(port, flags);
+ 	}
+ 
++	/*
++	 * Add the PPS support for the current port.
++	 */
++	if (port->flags & UPF_HARDPPS_CD)
++		uart_register_pps_port(state, port);
++
+ 	if (port->type != PORT_UNKNOWN) {
+ 		unsigned long flags;
+ 
+@@ -2359,6 +2422,12 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
+ 	mutex_unlock(&state->mutex);
+ 
+ 	/*
++	 * Remove PPS support from the current port.
++	 */
++	if (port->flags & UPF_HARDPPS_CD)
++		uart_unregister_pps_port(state, port);
++
++	/*
+ 	 * Remove the devices from the tty layer
+ 	 */
+ 	tty_unregister_device(drv->tty_driver, port->line);
+diff --git a/include/linux/Kbuild b/include/linux/Kbuild
+index 818cc3a..0a9394f 100644
+--- a/include/linux/Kbuild
++++ b/include/linux/Kbuild
+@@ -295,6 +295,7 @@ unifdef-y += pmu.h
+ unifdef-y += poll.h
+ unifdef-y += ppp_defs.h
+ unifdef-y += ppp-comp.h
++unifdef-y += pps.h
+ unifdef-y += ptrace.h
+ unifdef-y += qnx4_fs.h
+ unifdef-y += quota.h
+diff --git a/include/linux/parport.h b/include/linux/parport.h
+index 9cdd694..549de6e 100644
+--- a/include/linux/parport.h
++++ b/include/linux/parport.h
+@@ -100,6 +100,7 @@ typedef enum {
+ #include <linux/proc_fs.h>
+ #include <linux/spinlock.h>
+ #include <linux/wait.h>
++#include <linux/pps.h>
+ #include <asm/system.h>
+ #include <asm/ptrace.h>
+ #include <asm/semaphore.h>
+@@ -327,6 +328,11 @@ struct parport {
+ 
+ 	struct list_head full_list;
+ 	struct parport *slaves[3];
++
++#ifdef CONFIG_PPS_CLIENT_LP
++	struct pps_source_info pps_info;
++	int pps_source;		/* PPS source ID */
++#endif
+ };
+ 
+ #define DEFAULT_SPIN_TIME 500 /* us */
+@@ -517,6 +523,12 @@ extern int parport_daisy_select (struct parport *port, int daisy, int mode);
+ /* Lowlevel drivers _can_ call this support function to handle irqs.  */
+ static __inline__ void parport_generic_irq(int irq, struct parport *port)
+ {
++#ifdef CONFIG_PPS_CLIENT_LP
++	pps_event(port->pps_source, PPS_CAPTUREASSERT, port);
++	dev_dbg(port->dev, "PPS assert at %lu on source #%d\n",
++		jiffies, port->pps_source);
++#endif
++
+ 	parport_ieee1284_interrupt (irq, port);
+ 	read_lock(&port->cad_lock);
+ 	if (port->cad && port->cad->irq_func)
+diff --git a/include/linux/pps.h b/include/linux/pps.h
+new file mode 100644
+index 0000000..5bdb593
+--- /dev/null
++++ b/include/linux/pps.h
+@@ -0,0 +1,196 @@
++/*
++ * pps.h -- PPS API kernel header.
++ *
++ *
++ * Copyright (C) 2005-2007   Rodolfo Giometti <[email protected]>
++ *
++ *   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.
++ */
++
++
++#ifndef _PPS_H_
++#define _PPS_H_
++
++/* Implementation note: the logical states ``assert'' and ``clear''
++ * are implemented in terms of the chip register, i.e. ``assert''
++ * means the bit is set.  */
++
++/*
++ * 3.2 New data structures
++ */
++
++#ifndef __KERNEL__
++#include <linux/types.h>
++#include <sys/time.h>
++#include <sys/ioctl.h>
++#else
++#include <linux/time.h>
++#endif
++
++#define PPS_API_VERS		1
++#define PPS_MAX_NAME_LEN	32
++
++/* 32-bit vs. 64-bit compatibility.
++ *
++ * 0n i386, the alignment of a uint64_t is only 4 bytes, while on most other
++ * architectures it's 8 bytes. On i386, there will be no padding between the
++ * two consecutive 'struct pps_ktime' members of struct pps_kinfo and struct
++ * pps_kparams. But on most platforms there will be padding to ensure correct
++ * alignment.
++ *
++ * The simple fix is probably to add an explicit padding.
++ *					 		[David Woodhouse]
++ */
++struct pps_ktime {
++	__u64 sec;
++	__u32 nsec;
++	__u32 flags;
++};
++#define PPS_TIME_INVALID	(1<<0)	/* used to specify timeout==NULL */
++
++struct pps_kinfo {
++	__u32 assert_sequence;		/* seq. num. of assert event */
++	__u32 clear_sequence; 		/* seq. num. of clear event */
++	struct pps_ktime assert_tu;	/* time of assert event */
++	struct pps_ktime clear_tu;	/* time of clear event */
++	int current_mode;		/* current mode bits */
++};
++
++struct pps_kparams {
++	int api_version;		/* API version # */
++	int mode;			/* mode bits */
++	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
++	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
++};
++
++/*
++ * 3.3 Mode bit definitions
++ */
++
++/* Device/implementation parameters */
++#define PPS_CAPTUREASSERT	0x01	/* capture assert events */
++#define PPS_CAPTURECLEAR	0x02	/* capture clear events */
++#define PPS_CAPTUREBOTH		0x03	/* capture assert and clear events */
++
++#define PPS_OFFSETASSERT	0x10	/* apply compensation for assert ev. */
++#define PPS_OFFSETCLEAR		0x20	/* apply compensation for clear ev. */
++
++#define PPS_CANWAIT		0x100	/* can we wait for an event? */
++#define PPS_CANPOLL		0x200	/* bit reserved for future use */
++
++/* Kernel actions */
++#define PPS_ECHOASSERT		0x40	/* feed back assert event to output */
++#define PPS_ECHOCLEAR		0x80	/* feed back clear event to output */
++
++/* Timestamp formats */
++#define PPS_TSFMT_TSPEC		0x1000	/* select timespec format */
++#define PPS_TSFMT_NTPFP		0x2000	/* select NTP format */
++
++/*
++ * 3.4.4 New functions: disciplining the kernel timebase
++ */
++
++/* Kernel consumers */
++#define PPS_KC_HARDPPS		0	/* hardpps() (or equivalent) */
++#define PPS_KC_HARDPPS_PLL	1	/* hardpps() constrained to
++					   use a phase-locked loop */
++#define PPS_KC_HARDPPS_FLL	2	/* hardpps() constrained to
++					   use a frequency-locked loop */
++/*
++ * Here begins the implementation-specific part!
++ */
++
++struct pps_fdata {
++	struct pps_kinfo info;
++	struct pps_ktime timeout;
++};
++
++#include <linux/ioctl.h>
++
++#define PPS_CHECK		_IO('P', 0)
++#define PPS_GETPARAMS		_IOR('P', 1, struct pps_kparams *)
++#define PPS_SETPARAMS		_IOW('P', 2, struct pps_kparams *)
++#define PPS_GETCAP		_IOR('P', 3, int *)
++#define PPS_FETCH		_IOWR('P', 4, struct pps_fdata *)
++
++#ifdef __KERNEL__
++
++#include <linux/cdev.h>
++#include <linux/device.h>
++
++#define PPS_VERSION		"5.0.0-rc2"
++#define PPS_MAX_SOURCES		16		/* should be enought... */
++
++/*
++ * Global defines
++ */
++
++/* The specific PPS source info */
++struct pps_source_info {
++	char name[PPS_MAX_NAME_LEN];		/* simbolic name */
++	char path[PPS_MAX_NAME_LEN];		/* path of connected device */
++	int mode;				/* PPS's allowed mode */
++
++	void (*echo)(int source, int event, void *data); /* PPS echo function */
++
++	struct module *owner;
++	struct device *dev;
++};
++
++/* The main struct */
++struct pps_device {
++	struct pps_source_info info;		/* PSS source info */
++
++	struct pps_kparams params;		/* PPS's current params */
++
++	__u32 assert_sequence;			/* PPS' assert event seq # */
++	__u32 clear_sequence;			/* PPS' clear event seq # */
++	struct pps_ktime assert_tu;
++	struct pps_ktime clear_tu;
++	int current_mode;			/* PPS mode at event time */
++
++	int go;					/* PPS event is arrived? */
++	wait_queue_head_t queue;		/* PPS event queue */
++
++	unsigned int id;			/* PPS source unique ID */
++	struct cdev cdev;
++	struct device *dev;
++	int devno;
++	struct fasync_struct *async_queue;	/* fasync method */
++	spinlock_t lock;
++
++	atomic_t usage;				/* usage count */
++	wait_queue_head_t usage_queue;
++
++	struct class_device class_dev;
++};
++
++/*
++ * Exported functions
++ */
++
++extern int pps_register_source(struct pps_source_info *info,
++				int default_params);
++extern void pps_unregister_source(int source);
++extern int pps_register_cdev(struct pps_device *pps);
++extern void pps_unregister_cdev(struct pps_device *pps);
++extern void pps_event(int source, int event, void *data);
++
++extern int pps_sysfs_create_source_entry(struct pps_device *pps);
++extern void pps_sysfs_remove_source_entry(struct pps_device *pps);
++
++#endif /* __KERNEL__ */
++
++#endif /* _PPS_H_ */
+diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
+index 09d17b0..f9aefad 100644
+--- a/include/linux/serial_core.h
++++ b/include/linux/serial_core.h
+@@ -157,6 +157,7 @@
+ #include <linux/tty.h>
+ #include <linux/mutex.h>
+ #include <linux/sysrq.h>
++#include <linux/pps.h>
+ 
+ struct uart_port;
+ struct uart_info;
+@@ -236,6 +237,9 @@ struct uart_port {
+ 	unsigned char		regshift;		/* reg offset shift */
+ 	unsigned char		iotype;			/* io access style */
+ 	unsigned char		unused1;
++#ifdef CONFIG_PPS_CLIENT_UART
++	int			pps_source;		/* PPS source ID */
++#endif
+ 
+ #define UPIO_PORT		(0)
+ #define UPIO_HUB6		(1)
+@@ -280,7 +284,8 @@ struct uart_port {
+ #define UPF_IOREMAP		((__force upf_t) (1 << 31))
+ 
+ #define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
+-#define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
++#define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY\
++							|UPF_HARDPPS_CD))
+ 
+ 	unsigned int		mctrl;			/* current modem ctrl settings */
+ 	unsigned int		timeout;		/* character-based timeout */
+@@ -312,6 +317,10 @@ struct uart_state {
+ 	struct uart_info	*info;
+ 	struct uart_port	*port;
+ 
++#ifdef CONFIG_PPS_CLIENT_UART
++	struct pps_source_info	pps_info;
++#endif
++
+ 	struct mutex		mutex;
+ };
+ 
+@@ -476,13 +485,22 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status)
+ {
+ 	struct uart_info *info = port->info;
+ 
+-	port->icount.dcd++;
+-
+-#ifdef CONFIG_HARD_PPS
+-	if ((port->flags & UPF_HARDPPS_CD) && status)
+-		hardpps();
++#ifdef CONFIG_PPS_CLIENT_UART
++	if (port->flags & UPF_HARDPPS_CD) {
++		if (status) {
++			pps_event(port->pps_source, PPS_CAPTUREASSERT, port);
++			dev_dbg(port->dev, "PPS assert at %lu on source #%d\n",
++				jiffies, port->pps_source);
++		} else {
++			pps_event(port->pps_source, PPS_CAPTURECLEAR, port);
++			dev_dbg(port->dev, "PPS clear at %lu on source #%d\n",
++				jiffies, port->pps_source);
++		}
++	}
+ #endif
+ 
++	port->icount.dcd++;
++
+ 	if (info->flags & UIF_CHECK_CD) {
+ 		if (status)
+ 			wake_up_interruptible(&info->open_wait);