LinuxPPS & spinlocks

Rodolfo Giometti
2007-07-27T18:42:55Z

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By looking at spinlocks and thinking better to the lock problems for
pps_events() I found this (possible) solution...

The pps_event() is now protected by a spinlock against
pps_register_source() and pps_unregister_source(), but since I cannot
disable IRQs I used the spin_trylock() into the pps_events() so even
if the process context holds the lock and an PPS event arrives (IRQ)
the system doesn't hang. Note that we cannot lose an event without
problems.

It could be more acceptable? I removed the "volatile" attribute! :)

Rodolfo

--

GNU/Linux Solutions e-mail: giometti@enneenne.com
Linux Device Driver giometti@gnudd.com
Embedded Systems giometti@linux.it
UNIX programming phone: +39 349 2432127

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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..511fa36
--- /dev/null
+++ b/Documentation/pps/pps.txt
@@ -0,0 +1,211 @@
+
+ PPS - Pulse Per Second
+ ----------------------
+
+(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.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
+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 change the original RFC 2783:
+
+ pps_handle_t type is an opaque __scalar type__ used to represent a
+ PPS source within the API
+
+into a modified:
+
+ pps_handle_t type is an opaque __variable__ used to represent a PPS
+ source within the API and programs should not access it directly to
+ it due to its opacity.
+
+This change seems to be neglibile because even the original RFC 2783
+does not encourage programs to check (read: use) the pps_handle_t
+variable before calling the time_pps_*() functions, since each
+function should do this job internally.
+
+If I intentionally separate the concept of "file descriptor" from the
+concept of the "PPS source" I'm obliged to provide a solution to find
+and register a PPS-source without using a file descriptor: it's done
+by the functions time_pps_findsource() and time_pps_findpath() now.
+
+According to this current NTPD drivers' code should be modified as
+follows:
+
++#ifdef PPS_HAVE_FINDPATH
++ /* Get the PPS source's real name */
++ fd = readlink(link, path, STRING_LEN-1);
++ if (fd <= 0)
++ strncpy(path, link, STRING_LEN);
++ else
++ path[fd] = '\0';
++
++ /* Try to find the source */
++ fd = time_pps_findpath(path, STRING_LEN, id, STRING_LEN);
++ if (fd < 0) {
++ msyslog(LOG_ERR, "refclock: cannot find PPS source \"%s\" "
++ "in the system", path);
++ return 1;
++ }
++ msyslog(LOG_INFO, "refclock: found PPS source #%d \"%s\" on \"%s\"",
++ fd, path, id);
++#endif /* PPS_HAVE_FINDPATH */
++
++
+ if (time_pps_create(fd, &pps_handle) < 0) {
+- pps_handle = 0;
+ msyslog(LOG_ERR, "refclock: time_pps_create failed: %m");
+ }
+
+
+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,
+ };
+
+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,
+ -1 /* is up to the system */);
+
+The pps_register_source() prototype is:
+
+ int pps_register_source(struct pps_source_info_s *info, int default_params,
+ int try_id)
+
+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)
+and "try_id" can be used to force a particular ID for your device into
+the system (just use -1 if you wish the system chooses one for you).
+
+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
+-------------
+
+The SYSFS support is enabled by default if the SYSFS filesystem is
+enabled in the kernel and it provides a new class:
+
+ $ ls /sys/class/pps/
+ 00/ 01/ 02/
+
+Every directory is the ID of a PPS sources defined into the system and
+inside you find several files:
+
+ $ ls /sys/class/pps/00/
+ 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/00/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
+ found PPS source #0 "ktimer" on ""
+ ok, found 1 source(s), now start fetching data...
+ source 0 - assert 1183041017.838928410, sequence: 2 - clear 0.000000000, sequence: 0
+ source 0 - assert 1183041018.839023954, sequence: 3 - 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..17afcbd
--- /dev/null
+++ b/Documentation/pps/ppsctl.c
@@ -0,0 +1,61 @@
+#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, 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/ppstest.c b/Documentation/pps/ppstest.c
new file mode 100644
index 0000000..bfd1064
--- /dev/null
+++ b/Documentation/pps/ppstest.c
@@ -0,0 +1,201 @@
+#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>
+
+#define STRING_LEN PPS_MAX_NAME_LEN
+
+int find_source(int try_link, char *link, pps_handle_t *handle,
+ int *avail_mode)
+{
+ int num = -1;
+ char id[STRING_LEN] = "", /* no ID string by default */
+ path[STRING_LEN];
+ pps_params_t params;
+ int ret;
+
+ if (try_link) {
+ printf("trying PPS source \"%s\"\n", link);
+#ifdef PPS_HAVE_FINDPATH
+ /* Get the PPS source's real name */
+ time_pps_readlink(link, STRING_LEN, path, STRING_LEN);
+
+ /* Try to find the source by using the supplied "path" name */
+ ret = time_pps_findpath(path, STRING_LEN, id, STRING_LEN);
+ if (ret < 0)
+ goto exit;
+ num = ret;
+#else
+#warning "cannot use time_pps_findpath()"
+ ret = -1;
+#endif /* PPS_HAVE_FINDPATH */
+ }
+#ifdef PPS_HAVE_FINDSOURCE
+ /* Try to find the source (by using "index = -1" we ask just
+ * for a generic source) */
+ ret = time_pps_findsource(num, path, STRING_LEN, id, STRING_LEN);
+#else
+#warning "cannot use time_pps_findsource()"
+ ret = -1;
+#endif /* PPS_HAVE_FINDSOURCE */
+ if (ret < 0) {
+exit:
+ fprintf(stderr, "no available PPS source in the system\n");
+ return -1;
+ }
+ num = ret;
+ printf("found PPS source #%d \"%s\" on \"%s\"\n", num, id, path);
+
+ /* If "path" is not NULL we should *at least* open the pointed
+ * device in order to enable the interrupts generation.
+ * Note that this can be NOT enough anyway, infact you may need sending
+ * additional commands to your GPS antenna before it starts sending
+ * the PPS signal. */
+ if (strlen(path)) {
+ ret = open(path, O_RDWR);
+ if (ret < 0) {
+ fprintf(stderr, "cannot open \"%s\" (%m)\n", path);
+ return -1;
+ }
+ }
+
+ /* Open the PPS source */
+ ret = time_pps_create(num, handle);
+ if (ret < 0) {
+ fprintf(stderr, "cannot create a PPS source (%m)\n");
+ return -1;
+ }
+
+ /* 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;
+}
+
+int main(int argc, char *argv[])
+{
+ int num, try_link = 0; /* by default use findsource */
+ char link[STRING_LEN] = "/dev/gps0"; /* just a default device */
+ pps_handle_t handle[4];
+ int avail_mode[4];
+ int i = 0, ret;
+
+ if (argc == 1) {
+ ret = find_source(try_link, link, &handle[0], &avail_mode[0]);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ num = 1;
+ } else {
+ for (i = 1; i < argc && i <= 4; i++) {
+ ret = sscanf(argv[i], "%d", &num);
+ if (ret < 1) {
+ try_link = ~0;
+ strncpy(link, argv[i], STRING_LEN);
+ }
+
+ ret =
+ find_source(try_link, link, &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..dee1782
--- /dev/null
+++ b/Documentation/pps/timepps.h
@@ -0,0 +1,234 @@
+/*
+ * timepps.h -- PPS API main header
+ *
+ * Copyright (C) 2005-2007 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.
+ */
+
+#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 to represent 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
+ */
+
+#define PPS_HAVE_FINDSOURCE 1
+#define pps_min(a, b) (a) < (b) ? a : b
+int time_pps_findsource(int index, char *path, int pathlen, char *idstring,
+ int idlen)
+{
+ struct pps_source_data_s data;
+ int ret;
+
+ data.source = index;
+
+ ret = syscall(__NR_time_pps_cmd, PPS_CMD_FIND_SRC, &data);
+ if (ret < 0)
+ return ret;
+
+ strncpy(idstring, data.name, pps_min(idlen, PPS_MAX_NAME_LEN));
+ strncpy(path, data.path, pps_min(pathlen, PPS_MAX_NAME_LEN));
+
+ return data.source;
+}
+
+/* Defined iff PPS_HAVE_FINDPATH is defined */
+void time_pps_readlink(char *link, int linklen, char *path, int pathlen)
+{
+ int i;
+
+ i = readlink(link, path, pathlen - 1);
+ if (i <= 0) {
+ /* "link" is not a valid symbolic so we directly use it */
+ strncpy(path, link, linklen <= pathlen ? linklen : pathlen);
+ return;
+ }
+
+ /* Return the file name where "link" points to */
+ path[i] = '\0';
+}
+
+#define PPS_HAVE_FINDPATH 1
+int time_pps_findpath(char *path, int pathlen, char *idstring, int idlen)
+{
+ struct pps_source_data_s data;
+ int ret;
+
+ strncpy(data.path, path, pps_min(pathlen, PPS_MAX_NAME_LEN));
+
+ ret = syscall(__NR_time_pps_cmd, PPS_CMD_FIND_PATH, &data);
+ if (ret < 0)
+ return ret;
+
+ strncpy(idstring, data.name, pps_min(idlen, PPS_MAX_NAME_LEN));
+
+ return data.source;
+}
+
+int time_pps_create(int source, pps_handle_t *handle)
+{
+ if (!handle) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* In LinuxPPS there are no differences between a PPS source and
+ * a PPS handle so we return the same value.
+ */
+ *handle = source;
+
+ return 0;
+}
+
+int time_pps_destroy(pps_handle_t handle)
+{
+ /* Nothing to destroy here */
+
+ return 0;
+}
+
+int time_pps_getparams(pps_handle_t handle, pps_params_t *ppsparams)
+{
+ int ret;
+ struct pps_kparams __ppsparams;
+
+ ret = syscall(__NR_time_pps_getparams, handle, &__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;
+}
+
+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 syscall(__NR_time_pps_getparams, handle, &__ppsparams);
+}
+
+/* Get capabilities for handle */
+int time_pps_getcap(pps_handle_t handle, int *mode)
+{
+ return syscall(__NR_time_pps_getcap, handle, mode);
+}
+
+int time_pps_fetch(pps_handle_t handle, const int tsformat,
+ pps_info_t *ppsinfobuf, const struct timespec *timeout)
+{
+ struct pps_kinfo __ppsinfobuf;
+ struct pps_ktime __timeout;
+ int ret;
+
+ /* Sanity checks */
+ if (tsformat != PPS_TSFMT_TSPEC) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (timeout) {
+ __timeout.sec = timeout->tv_sec;
+ __timeout.nsec = timeout->tv_nsec;
+ }
+
+ ret = syscall(__NR_time_pps_fetch, handle, &__ppsinfobuf,
+ timeout ? &__timeout : NULL);
+
+ ppsinfobuf->assert_sequence = __ppsinfobuf.assert_sequence;
+ ppsinfobuf->clear_sequence = __ppsinfobuf.clear_sequence;
+ ppsinfobuf->assert_tu.tspec.tv_sec = __ppsinfobuf.assert_tu.sec;
+ ppsinfobuf->assert_tu.tspec.tv_nsec = __ppsinfobuf.assert_tu.nsec;
+ ppsinfobuf->clear_tu.tspec.tv_sec = __ppsinfobuf.clear_tu.sec;
+ ppsinfobuf->clear_tu.tspec.tv_nsec = __ppsinfobuf.clear_tu.nsec;
+ ppsinfobuf->current_mode = __ppsinfobuf.current_mode;
+
+ return ret;
+}
+
+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 df40a4e..17e9a02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2903,6 +2903,13 @@ P: Michal Ostrowski
M: mostrows@speakeasy.net
S: Maintained

+PPS SUPPORT
+P: Rodolfo Giometti
+M: giometti@enneenne.com
+W: http://wiki.enneenne.com/index.php/LinuxPPS_support
+L: linuxpps@ml.enneenne.com
+S: Maintained
+
PREEMPTIBLE KERNEL
P: Robert Love
M: rml@tech9.net
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index bf6adce..f1bf4ff 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -323,3 +323,8 @@ ENTRY(sys_call_table)
.long sys_signalfd
.long sys_timerfd
.long sys_eventfd
+ .long sys_time_pps_cmd
+ .long sys_time_pps_getparams /* 325 */
+ .long sys_time_pps_setparams
+ .long sys_time_pps_getcap
+ .long sys_time_pps_fetch
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 050323f..bb54cab 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/hwmon/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index adad2f3..985d495 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -60,6 +60,7 @@ 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_HWMON) += hwmon/
obj-$(CONFIG_PHONE) += telephony/
diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 62051f8..8b2e41f 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 +838,37 @@ static int lp_register(int nr, struct parport *port)
}
#endif

+#ifdef CONFIG_PPS_CLIENT_LP
+ 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,
+ -1 /* is up to the system */);
+ 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 +912,14 @@ 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_info));
+ 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..a00b59a
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,31 @@
+#
+# PPS support configuration
+#
+
+menu "PPS support"
+
+config PPS
+ bool "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.
+
+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..58a1e55
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,30 @@
+#
+# 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.
+
+config PPS_CLIENT_UART
+ bool "UART serial support"
+ help
+ If you say yes here you get support for a PPS source connected
+ with the CD (Carrier Detect) pin of your serial port.
+
+config PPS_CLIENT_LP
+ bool "Parallel printer support"
+ 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..c5d83f5
--- /dev/null
+++ b/drivers/pps/clients/ktimer.c
@@ -0,0 +1,114 @@
+/*
+ * 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.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_s pps_ktimer_info = {
+ name : "ktimer",
+ path : "",
+ mode : PPS_CAPTUREASSERT | PPS_OFFSETASSERT | \
+ PPS_ECHOASSERT | \
+ PPS_CANWAIT | PPS_TSFMT_TSPEC,
+ echo : pps_ktimer_echo,
+};
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_ktimer_exit(void)
+{
+ del_timer_sync(&ktimer);
+ pps_unregister_source(&pps_ktimer_info);
+
+ 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,
+ -1 /* is up to the system */);
+ 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");
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
new file mode 100644
index 0000000..7aa32c6
--- /dev/null
+++ b/drivers/pps/kapi.c
@@ -0,0 +1,222 @@
+/*
+ * kapi.c -- kernel API
+ *
+ *
+ * Copyright (C) 2005-2007 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/sched.h>
+#include <linux/time.h>
+#include <linux/spinlock.h>
+#include <linux/pps.h>
+
+/*
+ * Local variables
+ */
+
+static spinlock_t pps_lock = SPIN_LOCK_UNLOCKED;
+
+/*
+ * 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_s *info, int default_params,
+ int try_id)
+{
+ int i = -1, err = 0, ret;
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ if (try_id >= 0) {
+ if (pps_is_allocated(try_id)) {
+ printk(KERN_ERR "source id %d busy\n", try_id);
+ err = -EBUSY;
+ goto pps_register_source_exit;
+ }
+ i = try_id;
+ } else {
+ for (i = 0; i < PPS_MAX_SOURCES; i++)
+ if (!pps_is_allocated(i))
+ break;
+ if (i >= PPS_MAX_SOURCES) {
+ printk(KERN_ERR "no free source IDs\n");
+ err = -ENOMEM;
+ goto pps_register_source_exit;
+ }
+ }
+
+ /* Sanity checks */
+ if ((info->mode & default_params) != default_params) {
+ printk(KERN_ERR "unsupported default parameters\n");
+ err = -EINVAL;
+ goto pps_register_source_exit;
+ }
+ if ((info->mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) != 0 &&
+ info->echo == NULL) {
+ printk(KERN_ERR "echo function is not defined\n");
+ err = -EINVAL;
+ goto pps_register_source_exit;
+ }
+ if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
+ printk(KERN_ERR "unspecified time format\n");
+ err = -EINVAL;
+ goto pps_register_source_exit;
+ }
+
+ spin_lock(&pps_lock);
+
+ /* Init the PPS source main struct */
+ memset(&pps_source[i], 0, sizeof(struct pps_s));
+ pps_source[i].params.api_version = PPS_API_VERS;
+ pps_source[i].params.mode = default_params;
+ init_waitqueue_head(&pps_source[i].queue);
+ pps_source[i].info = info;
+
+ spin_unlock(&pps_lock);
+
+pps_register_source_exit :
+ mutex_unlock(&pps_mutex);
+
+ if (err < 0)
+ return err;
+
+ ret = pps_sysfs_create_source_entry(info, i);
+ if (ret < 0)
+ printk(KERN_ERR "unable to create sysfs entry for source %d\n",
+ i);
+
+ return i;
+}
+EXPORT_SYMBOL(pps_register_source);
+
+void pps_unregister_source(struct pps_source_info_s *info)
+{
+ int i;
+
+ pps_sysfs_remove_source_entry(info);
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return;
+
+ for (i = 0; i < PPS_MAX_SOURCES; i++)
+ if (pps_is_allocated(i) && pps_source[i].info == info)
+ break;
+
+ if (i >= PPS_MAX_SOURCES) {
+ printk(KERN_ERR "warning! Try to unregister an unknown "
+ "PPS source\n");
+ goto pps_unregister_source_exit;
+ }
+
+ spin_lock(&pps_lock);
+
+ /* Deallocate the PPS source */
+ memset(&pps_source[i], 0, sizeof(struct pps_s));
+
+ spin_unlock(&pps_lock);
+
+pps_unregister_source_exit :
+ mutex_unlock(&pps_mutex);
+}
+EXPORT_SYMBOL(pps_unregister_source);
+
+void pps_event(int source, int event, void *data)
+{
+ struct timespec __ts;
+ struct pps_ktime ts;
+
+ /* 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 "unknown event (%x) for source %d\n",
+ event, source);
+ return;
+ }
+
+ /* Try to grab the lock, if not we prefere loose the event... */
+ if (!spin_trylock(&pps_lock))
+ return;
+
+ if (!pps_source[source].info) {
+ spin_unlock(&pps_lock);
+ return;
+ }
+
+ /* Must call the echo function? */
+ if ((pps_source[source].params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
+ pps_source[source].info->echo(source, event, data);
+
+ /* Check the event */
+ pps_source[source].current_mode = pps_source[source].params.mode;
+ if (event & PPS_CAPTUREASSERT) {
+ /* We have to add an offset? */
+ if (pps_source[source].params.mode & PPS_OFFSETASSERT)
+ pps_add_offset(&ts,
+ &pps_source[source].params.assert_off_tu);
+
+ /* Save the time stamp */
+ pps_source[source].assert_tu = ts;
+ pps_source[source].assert_sequence++;
+ pr_debug("capture assert seq #%u for source %d\n",
+ pps_source[source].assert_sequence, source);
+ }
+ if (event & PPS_CAPTURECLEAR) {
+ /* We have to add an offset? */
+ if (pps_source[source].params.mode & PPS_OFFSETCLEAR)
+ pps_add_offset(&ts,
+ &pps_source[source].params.clear_off_tu);
+
+ /* Save the time stamp */
+ pps_source[source].clear_tu = ts;
+ pps_source[source].clear_sequence++;
+ pr_debug("capture clear seq #%u for source %d\n",
+ pps_source[source].clear_sequence, source);
+ }
+
+ pps_source[source].go = ~0;
+ wake_up_interruptible(&pps_source[source].queue);
+
+ spin_unlock(&pps_lock);
+}
+EXPORT_SYMBOL(pps_event);
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 0000000..9176c01
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,391 @@
+/*
+ * pps.c -- Main PPS support file
+ *
+ *
+ * Copyright (C) 2005-2007 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/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/sched.h>
+#include <linux/pps.h>
+#include <linux/uaccess.h>
+
+/*
+ * Global variables
+ */
+
+struct pps_s pps_source[PPS_MAX_SOURCES];
+DEFINE_MUTEX(pps_mutex);
+
+/*
+ * Misc functions
+ */
+
+static inline int pps_check_source(int source)
+{
+ return (source < 0 || !pps_is_allocated(source)) ? -EINVAL : 0;
+}
+
+static int pps_find_source(int source)
+{
+ int i;
+
+ if (source >= 0) {
+ if (source >= PPS_MAX_SOURCES || !pps_is_allocated(source))
+ return -EINVAL;
+ else
+ return source;
+ }
+
+ for (i = 0; i < PPS_MAX_SOURCES; i++)
+ if (pps_is_allocated(i))
+ break;
+
+ if (i >= PPS_MAX_SOURCES)
+ return -EINVAL;
+
+ return i;
+}
+
+static int pps_find_path(char *path)
+{
+ int i;
+
+ for (i = 0; i < PPS_MAX_SOURCES; i++)
+ if (pps_is_allocated(i) &&
+ (strncmp(pps_source[i].info->path, path,
+ PPS_MAX_NAME_LEN) == 0 ||
+ strncmp(pps_source[i].info->name, path,
+ PPS_MAX_NAME_LEN) == 0))
+ break;
+
+ if (i >= PPS_MAX_SOURCES)
+ return -EINVAL;
+
+ return i;
+}
+
+/*
+ * PPS System Calls
+ */
+
+asmlinkage long sys_time_pps_cmd(int cmd, void __user *arg)
+{
+ struct pps_source_data_s data;
+ int ret = 0;
+
+ pr_debug("%s: cmd %d\n", __FUNCTION__, cmd);
+
+ /* Sanity checks */
+ if (_IOC_TYPE(cmd) != 'P')
+ return -EOPNOTSUPP;
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ switch (cmd) {
+ case PPS_CMD_FIND_SRC :
+ ret = copy_from_user(&data, arg,
+ sizeof(struct pps_source_data_s));
+ if (ret) {
+ ret = -EFAULT;
+ goto sys_time_pps_cmd_exit;
+ }
+
+ pr_debug("PPS_CMD_FIND_SRC: source %d\n", data.source);
+
+ data.source = pps_find_source(data.source);
+ if (data.source < 0) {
+ pr_debug("no PPS devices found\n");
+ ret = -ENODEV;
+ goto sys_time_pps_cmd_exit;
+ }
+
+ break;
+
+ case PPS_CMD_FIND_PATH :
+ ret = copy_from_user(&data, arg,
+ sizeof(struct pps_source_data_s));
+ if (ret) {
+ ret = -EFAULT;
+ goto sys_time_pps_cmd_exit;
+ }
+
+ pr_debug("PPS_CMD_FIND_PATH: path %s\n", data.path);
+
+ data.source = pps_find_path(data.path);
+ if (data.source < 0) {
+ pr_debug("no PPS devices found\n");
+ ret = -ENODEV;
+ goto sys_time_pps_cmd_exit;
+ }
+
+ break;
+
+ default :
+ printk(KERN_ERR "invalid sys_time_pps_cmd %d\n", cmd);
+ ret = -EOPNOTSUPP;
+ goto sys_time_pps_cmd_exit;
+ }
+
+ /* Found! So copy the info */
+ strncpy(data.name, pps_source[data.source].info->name,
+ PPS_MAX_NAME_LEN);
+ strncpy(data.path, pps_source[data.source].info->path,
+ PPS_MAX_NAME_LEN);
+
+ ret = copy_to_user(arg, &data, sizeof(struct pps_source_data_s));
+ if (ret)
+ ret = -EFAULT;
+
+sys_time_pps_cmd_exit:
+ mutex_unlock(&pps_mutex);
+
+ return ret;
+}
+
+asmlinkage long sys_time_pps_getparams(int source,
+ struct pps_kparams __user *params)
+{
+ int ret = 0;
+
+ pr_debug("%s: source %d\n", __FUNCTION__, source);
+
+ /* Sanity checks */
+ if (!params)
+ return -EINVAL;
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ ret = pps_check_source(source);
+ if (ret < 0) {
+ ret = -ENODEV;
+ goto sys_time_pps_getparams_exit;
+ }
+
+ /* Return current parameters */
+ ret = copy_to_user(params, &pps_source[source].params,
+ sizeof(struct pps_kparams));
+ if (ret)
+ ret = -EFAULT;
+
+sys_time_pps_getparams_exit:
+ mutex_unlock(&pps_mutex);
+
+ return ret;
+}
+
+asmlinkage long sys_time_pps_setparams(int source,
+ const struct pps_kparams __user *params)
+{
+ int ret;
+
+ pr_debug("%s: source %d\n", __FUNCTION__, source);
+
+ /* Check the capabilities */
+ if (!capable(CAP_SYS_TIME))
+ return -EPERM;
+
+ /* Sanity checks */
+ if (!params)
+ return -EINVAL;
+ if ((params->mode & ~pps_source[source].info->mode) != 0) {
+ pr_debug("unsupported capabilities\n");
+ return -EINVAL;
+ }
+ if ((params->mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
+ pr_debug("capture mode unspecified\n");
+ return -EINVAL;
+ }
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ ret = pps_check_source(source);
+ if (ret < 0) {
+ ret = -ENODEV;
+ goto sys_time_pps_setparams_exit;
+ }
+
+ /* Save the new parameters */
+ ret = copy_from_user(&pps_source[source].params, params,
+ sizeof(struct pps_kparams));
+ if (ret) {
+ ret = -EFAULT;
+ goto sys_time_pps_setparams_exit;
+ }
+
+ /* 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\n");
+ pps_source[source].params.mode |= PPS_TSFMT_TSPEC;
+ }
+ if (pps_source[source].info->mode & PPS_CANWAIT)
+ pps_source[source].params.mode |= PPS_CANWAIT;
+ pps_source[source].params.api_version = PPS_API_VERS;
+
+sys_time_pps_setparams_exit:
+ mutex_unlock(&pps_mutex);
+
+ return ret;
+}
+
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode)
+{
+ int ret;
+
+ pr_debug("%s: source %d\n", __FUNCTION__, source);
+
+ /* Sanity checks */
+ if (!mode)
+ return -EINVAL;
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ ret = pps_check_source(source);
+ if (ret < 0) {
+ ret = -ENODEV;
+ goto sys_time_pps_getcap_exit;
+ }
+
+ ret = put_user(pps_source[source].info->mode, mode);
+
+sys_time_pps_getcap_exit:
+ mutex_unlock(&pps_mutex);
+
+ return ret;
+}
+
+asmlinkage long sys_time_pps_fetch(int source, struct pps_kinfo __user *info,
+ const struct pps_ktime __user *timeout)
+{
+ unsigned long ticks;
+ struct pps_kinfo pi;
+ struct pps_ktime to;
+ int ret;
+
+ pr_debug("%s: source %d\n", __FUNCTION__, source);
+
+ if (!info)
+ return -EINVAL;
+
+ if (mutex_lock_interruptible(&pps_mutex))
+ return -EINTR;
+
+ ret = pps_check_source(source);
+ if (ret < 0) {
+ ret = -ENODEV;
+ goto sys_time_pps_fetch_exit;
+ }
+
+ pps_source[source].go = 0;
+
+ /* Manage the timeout */
+ if (timeout) {
+ ret = copy_from_user(&to, timeout, sizeof(struct pps_ktime));
+ if (ret) {
+ goto sys_time_pps_fetch_exit;
+ ret = -EFAULT;
+ }
+ pr_debug("timeout %lld.%09d\n", to.sec, to.nsec);
+ ticks = to.sec * HZ;
+ ticks += to.nsec / (NSEC_PER_SEC / HZ);
+
+ if (ticks != 0) {
+ ret = wait_event_interruptible_timeout(
+ pps_source[source].queue,
+ pps_source[source].go, ticks);
+ if (ret == 0) {
+ pr_debug("timeout expired\n");
+ ret = -ETIMEDOUT;
+ goto sys_time_pps_fetch_exit;
+ }
+ }
+ } else
+ ret = wait_event_interruptible(pps_source[source].queue,
+ pps_source[source].go);
+
+ /* Check for pending signals */
+ if (ret == -ERESTARTSYS) {
+ pr_debug("pending signal caught\n");
+ ret = -EINTR;
+ goto sys_time_pps_fetch_exit;
+ }
+
+ /* Return the fetched timestamp */
+ pi.assert_sequence = pps_source[source].assert_sequence;
+ pi.clear_sequence = pps_source[source].clear_sequence;
+ pi.assert_tu = pps_source[source].assert_tu;
+ pi.clear_tu = pps_source[source].clear_tu;
+ pi.current_mode = pps_source[source].current_mode;
+ ret = copy_to_user(info, &pi, sizeof(struct pps_kinfo));
+ if (ret)
+ ret = -EFAULT;
+
+sys_time_pps_fetch_exit:
+ mutex_unlock(&pps_mutex);
+
+ return ret;
+}
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_exit(void)
+{
+ pps_sysfs_unregister();
+
+ pr_info("LinuxPPS API ver. %d removed\n", PPS_API_VERS);
+}
+
+static int __init pps_init(void)
+{
+ int i, ret;
+
+ /* Init pps_source info */
+ for (i = 0; i < PPS_MAX_SOURCES; i++)
+ memset(&pps_source[i], 0, sizeof(struct pps_s));
+
+ /* Register to sysfs */
+ ret = pps_sysfs_register();
+ if (ret < 0) {
+ printk(KERN_ERR "unable to register sysfs\n");
+ return ret;
+ }
+
+ pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
+ pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+ "<giometti@linux.it>\n", PPS_VERSION);
+
+ return 0;
+}
+
+subsys_initcall(pps_init);
+module_exit(pps_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+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..e52dd8e
--- /dev/null
+++ b/drivers/pps/sysfs.c
@@ -0,0 +1,217 @@
+/*
+ * sysfs.c -- sysfs support
+ *
+ *
+ * Copyright (C) 2007 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/device.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <linux/pps.h>
+
+/*
+ * Private functions
+ */
+
+static ssize_t pps_show_assert(struct class_device *cdev, char *buf)
+{
+ struct pps_s *dev = class_get_devdata(cdev);
+
+ return sprintf(buf, "%lld.%09d#%d\n",
+ dev->assert_tu.sec, dev->assert_tu.nsec,
+ dev->assert_sequence);
+}
+
+static ssize_t pps_show_clear(struct class_device *cdev, char *buf)
+{
+ struct pps_s *dev = class_get_devdata(cdev);
+
+ return sprintf(buf, "%lld.%09d#%d\n",
+ dev->clear_tu.sec, dev->clear_tu.nsec,
+ dev->clear_sequence);
+}
+
+static ssize_t pps_show_mode(struct class_device *cdev, char *buf)
+{
+ struct pps_source_info_s *info = to_pps_info(cdev);
+
+ return sprintf(buf, "%4x\n", info->mode);
+}
+
+static ssize_t pps_show_echo(struct class_device *cdev, char *buf)
+{
+ struct pps_source_info_s *info = to_pps_info(cdev);
+
+ return sprintf(buf, "%d\n", !!info->echo);
+}
+
+static ssize_t pps_show_name(struct class_device *cdev, char *buf)
+{
+ struct pps_source_info_s *info = to_pps_info(cdev);
+
+ return sprintf(buf, "%s\n", info->name);
+}
+
+static ssize_t pps_show_path(struct class_device *cdev, char *buf)
+{
+ struct pps_source_info_s *info = to_pps_info(cdev);
+
+ return sprintf(buf, "%s\n", info->path);
+}
+
+/*
+ * Files definitions
+ */
+
+#define DECLARE_INFO_ATTR(_name, _mode, _show, _store) \
+{ \
+ .attr = { \
+ .name = __stringify(_name), \
+ .mode = _mode, \
+ .owner = THIS_MODULE, \
+ }, \
+ .show = _show, \
+ .store = _store, \
+}
+
+static struct class_device_attribute pps_class_device_attributes[] = {
+ DECLARE_INFO_ATTR(assert, 0444, pps_show_assert, NULL),
+ DECLARE_INFO_ATTR(clear, 0444, pps_show_clear, NULL),
+ DECLARE_INFO_ATTR(mode, 0444, pps_show_mode, NULL),
+ DECLARE_INFO_ATTR(echo, 0444, pps_show_echo, NULL),
+ DECLARE_INFO_ATTR(name, 0444, pps_show_name, NULL),
+ DECLARE_INFO_ATTR(path, 0444, pps_show_path, NULL),
+};
+
+/*
+ * Class definitions
+ */
+
+static void pps_class_release(struct class_device *cdev)
+{
+ /* Nop??? */
+}
+
+static struct class pps_class = {
+ .name = "pps",
+ .release = pps_class_release,
+};
+
+/*
+ * Public functions
+ */
+
+void pps_sysfs_remove_source_entry(struct pps_source_info_s *info)
+{
+ int i;
+
+ /* Sanity checks */
+ if (info == NULL)
+ return;
+
+ /* Delete info files */
+ if (info->mode&PPS_CAPTUREASSERT)
+ class_device_remove_file(&info->class_dev,
+ &pps_class_device_attributes[0]);
+
+ if (info->mode&PPS_CAPTURECLEAR)
+ class_device_remove_file(&info->class_dev,
+ &pps_class_device_attributes[1]);
+
+ for (i = 2; i < ARRAY_SIZE(pps_class_device_attributes); i++)
+ class_device_remove_file(&info->class_dev,
+ &pps_class_device_attributes[i]);
+
+ /* Deregister the pps class */
+ class_device_unregister(&info->class_dev);
+}
+
+int pps_sysfs_create_source_entry(struct pps_source_info_s *info, int id)
+{
+ char buf[32];
+ int i, ret;
+
+ /* Sanity checks */
+ if (info == NULL || id >= PPS_MAX_SOURCES)
+ return -EINVAL;
+
+ /* Create dir class device name */
+ sprintf(buf, "%.02d", id);
+
+ /* Setup the class struct */
+ memset(&info->class_dev, 0, sizeof(struct class_device));
+ info->class_dev.class = &pps_class;
+ strlcpy(info->class_dev.class_id, buf, KOBJ_NAME_LEN);
+ class_set_devdata(&info->class_dev, &pps_source[id]);
+
+ /* Register the new class */
+ ret = class_device_register(&info->class_dev);
+ if (unlikely(ret))
+ goto error_class_device_register;
+
+ /* Create info files */
+
+ /* Create file "assert" and "clear" according to source capability */
+ if (info->mode & PPS_CAPTUREASSERT) {
+ ret = class_device_create_file(&info->class_dev,
+ &pps_class_device_attributes[0]);
+ i = 0;
+ if (unlikely(ret))
+ goto error_class_device_create_file;
+ }
+ if (info->mode & PPS_CAPTURECLEAR) {
+ ret = class_device_create_file(&info->class_dev,
+ &pps_class_device_attributes[1]);
+ i = 1;
+ if (unlikely(ret))
+ goto error_class_device_create_file;
+ }
+
+ for (i = 2; i < ARRAY_SIZE(pps_class_device_attributes); i++) {
+ ret = class_device_create_file(&info->class_dev,
+ &pps_class_device_attributes[i]);
+ if (unlikely(ret))
+ goto error_class_device_create_file;
+ }
+
+ return 0;
+
+error_class_device_create_file:
+ while (--i >= 0)
+ class_device_remove_file(&info->class_dev,
+ &pps_class_device_attributes[i]);
+
+ class_device_unregister(&info->class_dev);
+ /* Here the release() method was already called */
+
+error_class_device_register:
+
+ return ret;
+}
+
+void pps_sysfs_unregister(void)
+{
+ class_unregister(&pps_class);
+}
+
+int pps_sysfs_register(void)
+{
+ return class_register(&pps_class);
+}
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c84dab0..0c9a307 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2101,6 +2101,8 @@ 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 326020f..cc5b4fc 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 +634,53 @@ 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;
+
+ 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,
+ -1 /* PPS ID is up to the system */);
+ 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(&state->pps_info);
+ 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 +855,19 @@ 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,
@@ -2100,6 +2156,12 @@ 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;

@@ -2349,6 +2411,12 @@ 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/asm-i386/unistd.h b/include/asm-i386/unistd.h
index e84ace1..36746dc 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -329,10 +329,15 @@
#define __NR_signalfd 321
#define __NR_timerfd 322
#define __NR_eventfd 323
+#define __NR_time_pps_cmd 324
+#define __NR_time_pps_getparams 325
+#define __NR_time_pps_setparams 326
+#define __NR_time_pps_getcap 327
+#define __NR_time_pps_fetch 328

#ifdef __KERNEL__

-#define NR_syscalls 324
+#define NR_syscalls 329

#define __ARCH_WANT_IPC_PARSE_VERSION
#define __ARCH_WANT_OLD_READDIR
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index f317c27..a10d20a 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -293,6 +293,7 @@ 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..0ecce1f 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_s 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..6eca3ea
--- /dev/null
+++ b/include/linux/pps.h
@@ -0,0 +1,206 @@
+/*
+ * pps.h -- PPS API kernel header.
+ *
+ *
+ * Copyright (C) 2005-2007 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.
+ */
+
+
+#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>
+#else
+#include <linux/time.h>
+#endif
+
+#define PPS_API_VERS_2 2 /* LinuxPPS proposal, dated 2006-05 */
+#define PPS_API_VERS PPS_API_VERS_2
+#define LINUXPSS_API 1 /* mark LinuxPPS API */
+
+#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 padding;
+};
+
+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!
+ */
+
+#include <linux/ioctl.h>
+
+struct pps_source_data_s {
+ int source;
+ char name[PPS_MAX_NAME_LEN];
+ char path[PPS_MAX_NAME_LEN];
+};
+
+#define PPS_CMD_FIND_SRC _IOWR('P', 1, struct pps_source_data *)
+#define PPS_CMD_FIND_PATH _IOWR('P', 2, struct pps_source_data *)
+
+#ifdef __KERNEL__
+
+#include <linux/device.h>
+
+/*
+ * Misc macros
+ */
+
+#define PPS_VERSION "4.0.0-rc4"
+
+/*
+ * Global defines
+ */
+
+#define PPS_MAX_SOURCES 16
+
+/* The specific PPS source info */
+struct pps_source_info_s {
+ 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 */
+
+ /* sysfs section */
+ struct class_device class_dev;
+};
+
+/* The main struct */
+struct pps_s {
+ struct pps_source_info_s *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 */
+};
+
+/*
+ * Global variables
+ */
+
+extern struct pps_s pps_source[PPS_MAX_SOURCES];
+extern struct mutex pps_mutex;
+
+/*
+ * Global functions
+ */
+
+static inline int pps_is_allocated(int source)
+{
+ return pps_source[source].info != NULL;
+}
+
+#define to_pps_info(obj) container_of((obj), struct pps_source_info_s, class_dev)
+
+/*
+ * Exported functions
+ */
+
+extern int pps_register_source(struct pps_source_info_s *info,
+ int default_params, int try_id);
+extern void pps_unregister_source(struct pps_source_info_s *info);
+extern void pps_event(int source, int event, void *data);
+
+extern int pps_sysfs_create_source_entry(struct pps_source_info_s *info,
+ int id);
+extern void pps_sysfs_remove_source_entry(struct pps_source_info_s *info);
+extern int pps_sysfs_register(void);
+extern void pps_sysfs_unregister(void);
+
+#endif /* __KERNEL__ */
+
+#endif /* _PPS_H_ */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 7f2c99d..01f3459 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -153,6 +153,7 @@
#include <linux/tty.h>
#include <linux/mutex.h>
#include <linux/sysrq.h>
+#include <linux/pps.h>

struct uart_port;
struct uart_info;
@@ -232,6 +233,9 @@ 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)
@@ -276,7 +280,8 @@ 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 */
@@ -308,6 +313,10 @@ struct uart_state {
struct uart_info *info;
struct uart_port *port;

+#ifdef CONFIG_PPS_CLIENT_UART
+ struct pps_source_info_s pps_info;
+#endif
+
struct mutex mutex;
};

@@ -472,13 +481,22 @@ 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);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 83d0ec1..bfc8899 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -65,6 +65,7 @@ struct getcpu_cache;
#include <asm/signal.h>
#include <linux/quota.h>
#include <linux/key.h>
+#include <linux/pps.h>

asmlinkage long sys_time(time_t __user *tloc);
asmlinkage long sys_stime(time_t __user *tptr);
@@ -611,6 +612,15 @@ asmlinkage long sys_timerfd(int ufd, int clockid, int flags,
const struct itimerspec __user *utmr);
asmlinkage long sys_eventfd(unsigned int count);

+asmlinkage long sys_time_pps_cmd(int cmd, void __user *arg);
+asmlinkage long sys_time_pps_getparams(int source,
+ struct pps_kparams __user *params);
+asmlinkage long sys_time_pps_setparams(int source,
+ const struct pps_kparams __user *params);
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode);
+asmlinkage long sys_time_pps_fetch(int source, struct pps_kinfo __user *info,
+ const struct pps_ktime __user *timeout);
+
int kernel_execve(const char *filename, char *const argv[], char *const envp[]);

#endif
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 7e11e2c..e0fccc2 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -148,3 +148,10 @@ cond_syscall(sys_timerfd);
cond_syscall(compat_sys_signalfd);
cond_syscall(compat_sys_timerfd);
cond_syscall(sys_eventfd);
+
+/* PPS dependent */
+cond_syscall(sys_time_pps_find);
+cond_syscall(sys_time_pps_getparams);
+cond_syscall(sys_time_pps_setparams);
+cond_syscall(sys_time_pps_getcap);
+cond_syscall(sys_time_pps_fetch);