[PATCH] LinuxPPS (with new syscalls API)

[PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

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Hello,

here my new version of LinuxPPS with a new syscalls API.

Please take a look at this new patch and report any
suggestions/modifications so I can prepare a proper patch for kernel
inclusion.

Thanks in advance,

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.txt b/Documentation/pps.txt
new file mode 100644
index 0000000..f07b098
--- /dev/null
+++ b/Documentation/pps.txt
@@ -0,0 +1,183 @@
+
+			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).
diff --git a/MAINTAINERS b/MAINTAINERS
index cfd26dd..dd6784d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2860,6 +2860,13 @@ 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 0772678..ae1df31 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -320,3 +320,8 @@ ENTRY(sys_call_table)
 	.long sys_getcpu
 	.long sys_epoll_pwait
 	.long sys_utimensat		/* 320 */
+	.long sys_time_pps_cmd
+	.long sys_time_pps_getparams
+	.long sys_time_pps_setparams
+	.long sys_time_pps_getcap
+	.long sys_time_pps_fetch	/* 325 */
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 26ca903..97dc041 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -59,6 +59,7 @@ 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..a50b336 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 +838,35 @@ 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) 
+			pps_err("cannot register PPS source \"%s\"",
+					port->pps_info.path);	
+		else
+			pps_info("PPS source #%d \"%s\" added to the system",
+					port->pps_source, port->pps_info.path);
+	} else {
+		port->pps_source = -1;
+		pps_err("PPS support disabled due port \"%s\" is in polling mode",
+			port->pps_info.path);
+	}
+#endif
+
 	return 0;
 }
 
@@ -860,6 +910,14 @@ 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));
+		pps_dbg("PPS source #%d \"%s\" removed from the system",
+			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..0f5c784
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,34 @@
+#
+# Character device 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
+	  antennas. Userland can use it to get an high time reference.
+
+	  Some antennas' 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 antennas' PPS signals are connected with some special host
+	  inputs so you have to enable the corresponding client support.
+
+	  This PPS support can also be built as a module.  If so, the module
+	  will be called pps-core.
+
+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..76101cd
--- /dev/null
+++ b/drivers/pps/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the PPS core.
+#
+
+pps_core-objs			+= pps.o kapi.o sysfs.o
+obj-$(CONFIG_PPS)		+= pps_core.o
+obj-y				+= clients/
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
new file mode 100644
index 0000000..867df3a
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,30 @@
+#
+# LinuxPPS clients configuration
+#
+
+if PPS
+
+comment "PPS clients support"
+
+config PPS_CLIENT_KTIMER
+	tristate "Kernel timer client (Testing client, use for debug)"
+	help
+	  If you say yes here you get support for a PPS debugging client
+	  which uses a kernel timer to generate the PPS signal.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ktimer.o.
+
+config PPS_CLIENT_UART
+	bool "UART serial support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the CD (Carrier Detect) pin of your serial port.
+
+config PPS_CLIENT_LP
+	bool "Parallel printer support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the interrupt pin of your parallel port.
+
+endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
new file mode 100644
index 0000000..3ecca41
--- /dev/null
+++ b/drivers/pps/clients/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for miscellaneous I2C chip drivers.
+#
+
+obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= ktimer.o
+
diff --git a/drivers/pps/clients/ktimer.c b/drivers/pps/clients/ktimer.c
new file mode 100644
index 0000000..e9e5c47
--- /dev/null
+++ b/drivers/pps/clients/ktimer.c
@@ -0,0 +1,113 @@
+/*
+ * 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)
+{
+	pps_info("PPS event at %lu", 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)
+{
+	pps_info("echo %s %s for source %d",
+		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);
+
+	pps_info("ktimer PPS source unregistered");
+}
+
+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) {
+		pps_err("cannot register ktimer source");
+		return ret;
+	}
+	source = ret;
+
+	setup_timer(&ktimer, pps_ktimer_event, 0);
+	mod_timer(&ktimer, jiffies + HZ);
+
+	pps_info("ktimer PPS source registered at %d", source);
+
+	return  0;
+}
+
+module_init(pps_ktimer_init);
+module_exit(pps_ktimer_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("testing 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..dd24c31
--- /dev/null
+++ b/drivers/pps/kapi.c
@@ -0,0 +1,202 @@
+/*
+ * 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/pps.h>
+
+/* 
+ * Local functions
+ */
+
+static void pps_add_offset(struct timespec *ts, struct timespec *offset)
+{
+	ts->tv_nsec += offset->tv_nsec;
+	if (ts->tv_nsec >= NSEC_PER_SEC) {
+		ts->tv_nsec -= NSEC_PER_SEC;
+		ts->tv_sec++;
+	} else if (ts->tv_nsec < 0) {
+		ts->tv_nsec += NSEC_PER_SEC;
+		ts->tv_sec--;
+	}
+	ts->tv_sec += offset->tv_sec;
+}
+
+/*
+ * Exported functions
+ */
+
+static int __pps_register_source(struct pps_source_info_s *info,
+				int default_params, int try_id)
+{
+	int i;
+
+	if (try_id >= 0) {
+		if (pps_is_allocated(try_id)) {
+			pps_err("source id %d busy", try_id);
+			return -EBUSY;
+		}
+		i = try_id;
+	} else {
+		for (i = 0; i < PPS_MAX_SOURCES; i++)
+			if (!pps_is_allocated(i))
+				break;
+		if (i >= PPS_MAX_SOURCES) {
+			pps_err("no free source ids");
+			return -ENOMEM;
+		}
+	}
+
+	/* Sanity checks */
+	if ((info->mode & default_params) != default_params) {
+		pps_err("unsupported default parameters");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0 &&
+			info->echo == NULL) {
+		pps_err("echo function is not defined");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_TSFMT_TSPEC|PPS_TSFMT_NTPFP)) == 0) {
+		pps_err("unspecified time format");
+		return -EINVAL;
+	}
+
+	/* Allocate the PPS source.
+	 *
+	 * Note that we should reset all fields BUT "info" one! */
+	memset(&(pps_source[i].params), 0, sizeof(struct pps_params));
+	pps_source[i].params.api_version = PPS_API_VERS;
+	pps_source[i].params.mode = default_params;
+	pps_source[i].assert_sequence = 0;
+	pps_source[i].clear_sequence = 0;
+	pps_source[i].current_mode = 0;
+	pps_source[i].go = 0;
+	init_waitqueue_head(&pps_source[i].queue);
+
+	/* Allocate the PPS source */
+	pps_source[i].info = info;
+
+	return i;
+}
+
+int pps_register_source(struct pps_source_info_s *info, int default_params,
+			int try_id)
+{
+	int i, ret;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __pps_register_source(info, default_params, try_id);
+	mutex_unlock(&pps_mutex);
+
+	if (ret < 0)
+		return ret;
+	i = ret;
+
+	ret = pps_sysfs_create_source_entry(info, i);
+	if (ret < 0)
+		pps_err("unable to create sysfs entry for source %d", i);
+
+	return i;
+}
+EXPORT_SYMBOL(pps_register_source);
+
+static void __pps_unregister_source(struct pps_source_info_s *info)
+{  
+	int i;
+
+	for (i = 0; i < PPS_MAX_SOURCES; i++)
+		if (pps_is_allocated(i) && pps_source[i].info == info)
+			break;
+
+	if (i >= PPS_MAX_SOURCES) {
+		pps_err("warning! Try to unregister an unknow PPS source");
+		return;
+	}
+
+	/* Deallocate the PPS source */
+	pps_source[i].info = &dummy_info; 
+} 
+
+void pps_unregister_source(struct pps_source_info_s *info)
+{
+
+	pps_sysfs_remove_source_entry(info);
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return;
+	__pps_unregister_source(info);
+	mutex_unlock(&pps_mutex);
+}
+EXPORT_SYMBOL(pps_unregister_source);
+
+void pps_event(int source, int event, void *data)
+{
+	struct timespec ts;
+
+	/* First of all we get the time stamp... */
+	getnstimeofday(&ts);
+
+	if ((event & (PPS_CAPTUREASSERT|PPS_CAPTURECLEAR)) == 0 ) {
+		pps_err("unknow event (%x) for source %d", event, source);
+		return;
+	}
+
+	/* Must call the echo function? */
+	if ((pps_source[source].params.mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0)
+		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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].assert_tu.tspec = ts;
+		pps_source[source].assert_sequence++;
+		pps_dbg("capture assert seq #%lu for source %d", 
+			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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].clear_tu.tspec = ts;
+		pps_source[source].clear_sequence++;
+		pps_dbg("capture clear seq #%lu for source %d", 
+			pps_source[source].clear_sequence, source);
+	}
+
+	pps_source[source].go = ~0;
+	wake_up_interruptible(&pps_source[source].queue);
+}
+EXPORT_SYMBOL(pps_event);
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 0000000..a350a45
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,406 @@
+/*
+ * 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 <asm/uaccess.h>
+
+/*
+ * Global variables
+ */
+
+struct pps_s pps_source[PPS_MAX_SOURCES];
+DEFINE_MUTEX(pps_mutex);
+
+void dummy_echo(int source, int event, void *data) { }
+struct pps_source_info_s dummy_info;	/* Dummy PPS info for unallocated
+					   PPS sources */
+
+/*
+ * 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
+ */
+
+static long __sys_time_pps_cmd(int cmd, void __user *arg)
+{
+	struct pps_source_data_s *data = arg;
+
+	switch (cmd) {
+	case PPS_CMD_FIND_SRC :
+		pps_dbg("PPS_CMD_FIND_SRC: source %d", data->source);
+
+		data->source = pps_find_source(data->source);
+		if (data->source < 0) {
+			pps_dbg("no PPS devices found");
+			return -ENODEV;
+			break;
+	 	}
+
+		break;
+
+	case PPS_CMD_FIND_PATH :
+		pps_dbg("PPS_CMD_FIND_PATH: path %s", data->path);
+
+		data->source = pps_find_path(data->path);
+		if (data->source < 0) {
+			pps_dbg("no PPS devices found");
+			return -ENODEV;
+			break;
+	 	}
+
+		break;
+
+	default :
+		pps_err("invalid sys_time_pps_cmd %d", cmd);
+		return -EOPNOTSUPP;
+	}
+
+	/* 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);
+
+	return 0;
+}
+
+asmlinkage long sys_time_pps_cmd(int cmd, void __user *arg)
+{
+	int ret = -1;
+
+	pps_dbg("%s: cmd %d", __FUNCTION__, cmd);
+
+	/* Sanity checks */
+	if (_IOC_TYPE(cmd) != 'P')
+		return -EOPNOTSUPP;
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		ret = !access_ok(VERIFY_WRITE, arg, _IOC_SIZE(cmd));
+	else if (_IOC_DIR(cmd) & _IOC_WRITE)
+		ret = !access_ok(VERIFY_READ, arg, _IOC_SIZE(cmd));
+	if (ret)
+		return -EFAULT;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __sys_time_pps_cmd(cmd, arg);
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+static long __sys_time_pps_getparams(int source,
+					struct pps_params __user *params)
+{
+	int ret;
+
+	ret = pps_check_source(source);
+	if (ret < 0)
+		return -ENODEV;
+
+	*params = pps_source[source].params;
+
+	return 0;
+}
+
+asmlinkage long sys_time_pps_getparams(int source,
+					struct pps_params __user *params)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, params, sizeof(struct pps_params)))
+		return -EFAULT;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __sys_time_pps_getparams(source, params);
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+static long __sys_time_pps_setparams(int source,
+					const struct pps_params __user *params)
+{
+	int ret;
+
+	ret = pps_check_source(source);
+	if (ret < 0)
+		return -ENODEV;
+
+	/* Save the new parameters */
+	pps_source[source].params = *params;
+
+	/* Restore the read only parameters */
+	if ((params->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
+		/* section 3.3 of RFC 2783 interpreted */
+		pps_dbg("time format unspecified");
+		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;
+
+	return 0;
+}
+
+asmlinkage long sys_time_pps_setparams(int source,
+					const struct pps_params __user *params)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Check the capabilities */
+	if (!capable(CAP_SYS_TIME))
+		return -EPERM;
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_READ, params, sizeof(struct pps_params)))
+		return -EFAULT;
+	if ((params->mode & ~pps_source[source].info->mode) != 0) {
+		pps_dbg("unsupported capabilities");
+		return -EINVAL;
+ 	}
+	if ((params->mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
+		pps_dbg("capture mode unspecified");
+		return -EINVAL;
+	}
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __sys_time_pps_setparams(source, params);
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+static long __sys_time_pps_getcap(int source, int __user *mode)
+{
+	int ret;
+
+	ret = pps_check_source(source);
+	if (ret < 0)
+		return -ENODEV;
+
+	*mode = pps_source[source].info->mode;
+
+	return 0;
+}
+
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!mode)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, mode, sizeof(int)))
+		return -EFAULT;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __sys_time_pps_getcap(source, mode);
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+static long __sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec __user *timeout)
+{
+	unsigned long ticks;
+	int ret;
+
+	ret = pps_check_source(source);
+	if (ret < 0)
+		return -ENODEV;
+
+	pps_source[source].go = 0;
+
+ 	/* Manage the timeout */
+	if (timeout || timeout->tv_sec != -1) {
+		if (!access_ok(VERIFY_READ, timeout, sizeof(struct timespec)))
+			return -EFAULT;
+
+		pps_dbg("timeout %ld.%09ld", timeout->tv_sec, timeout->tv_nsec);
+		ticks = timeout->tv_sec * HZ;
+		ticks += timeout->tv_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) {
+				pps_dbg("timeout expired");
+				return -ETIMEDOUT;
+			}
+		}
+ 	} else
+		ret = wait_event_interruptible( pps_source[source].queue,
+				pps_source[source].go);
+
+	/* Check for pending signals */
+	if (ret == -ERESTARTSYS) {
+		pps_dbg("pending signal caught");
+		return -EINTR;
+	}
+
+	/* Return the fetched timestamp */
+	info->assert_sequence = pps_source[source].assert_sequence;
+	info->clear_sequence = pps_source[source].clear_sequence;
+	info->assert_tu = pps_source[source].assert_tu;
+	info->clear_tu = pps_source[source].clear_tu;
+	info->current_mode = pps_source[source].current_mode;
+
+	return 0;
+}
+
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec __user *timeout)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (tsformat != PPS_TSFMT_TSPEC) {
+		pps_dbg("unsupported time format");
+		return -EINVAL;
+ 	}
+	if (!info)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, info, sizeof(struct pps_info)))
+		return -EFAULT;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __sys_time_pps_fetch(source, tsformat, info, timeout);
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_exit(void)
+{
+	pps_sysfs_unregister();
+
+	pps_info("LinuxPPS API ver. %d removed", PPS_API_VERS);
+}
+
+static int __init pps_init(void)
+{
+	int i, ret;
+
+	/* Init pps_source info */
+	dummy_info.echo = dummy_echo;
+	for (i = 0; i < PPS_MAX_SOURCES; i++) {
+		pps_source[i].info = &dummy_info;
+		init_waitqueue_head(&pps_source[i].queue);
+	}
+
+	/* Register to sysfs */
+	ret = pps_sysfs_register();
+	if (ret < 0) {
+		pps_err("unable to register sysfs");
+		return ret;
+	}
+
+	pps_info("LinuxPPS API ver. %d registered", PPS_API_VERS);
+	pps_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+		"<giometti@linux.it>", 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..0dae24b
--- /dev/null
+++ b/drivers/pps/sysfs.c
@@ -0,0 +1,219 @@
+/*
+ * 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, "%ld.%09ld#%ld\n",
+			dev->assert_tu.tspec.tv_sec,
+			dev->assert_tu.tspec.tv_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, "%ld.%09ld#%ld\n",
+			dev->clear_tu.tspec.tv_sec,
+			dev->clear_tu.tspec.tv_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 48e259a..3e6ed91 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..4a9906f 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 +634,52 @@ 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) {
+		pps_err("cannot register PPS source \"%s\"", state->pps_info.path);
+		return ret;
+	}
+	port->pps_source = ret;
+	pps_info("PPS source #%d \"%s\" added to the system ",
+		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);
+	pps_dbg("PPS source #%d \"%s\" removed from the system",
+	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 +854,19 @@ 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 +2155,12 @@ 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 +2410,12 @@ 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 bd21e79..b3e7a31 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -326,10 +326,15 @@
 #define __NR_getcpu		318
 #define __NR_epoll_pwait	319
 #define __NR_utimensat		320
+#define __NR_time_pps_cmd	321
+#define __NR_time_pps_getparams	322
+#define __NR_time_pps_setparams	323
+#define __NR_time_pps_getcap	324
+#define __NR_time_pps_fetch	325
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 321
+#define NR_syscalls 326
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/include/linux/parport.h b/include/linux/parport.h
index 9cdd694..f53d9f4 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);
+	pps_dbg("parport_pc: PPS assert event at %lu on source #%d",
+		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..231dbe9
--- /dev/null
+++ b/include/linux/pps.h
@@ -0,0 +1,211 @@
+/*
+ * 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 <asm/types.h>
+#include <sys/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
+
+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 */
+};
+
+/*
+ * 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-rc1"
+
+#ifdef CONFIG_PPS_DEBUG
+#define pps_dbg(format, arg...) printk(KERN_DEBUG "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#else
+#define pps_dbg(format, arg...) do {} while (0)
+#endif
+
+#define pps_err(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#define pps_info(format, arg...) printk(KERN_INFO "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+
+/*
+ * 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);/* the 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_params params;		/* PPS's current params */
+
+	volatile unsigned long assert_sequence;	/* PPS' assert event seq # */
+	volatile unsigned long clear_sequence;	/* PPS' clear event seq # */
+	volatile union pps_timeu assert_tu;
+	volatile union pps_timeu 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;
+extern struct pps_source_info_s dummy_info;
+
+/*
+ * Global functions
+ */
+
+static inline int pps_is_allocated(int source)
+{
+	return pps_source[source].info != &dummy_info;
+}
+
+#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 aa2653a..01a6547 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -148,6 +148,7 @@
 #include <linux/sched.h>
 #include <linux/tty.h>
 #include <linux/mutex.h>
+#include <linux/pps.h>
 
 struct uart_port;
 struct uart_info;
@@ -227,6 +228,9 @@ 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)
@@ -271,7 +275,8 @@ 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 */
@@ -303,6 +308,10 @@ 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;
 };
 
@@ -467,13 +476,23 @@ 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);
+			pps_dbg("serial8250: PPS assert event at %lu on source #%d",
+				jiffies, port->pps_source);
+		}
+		else {
+			pps_event(port->pps_source, PPS_CAPTURECLEAR, port);
+			pps_dbg("serial8250: PPS clear event at %lu on source #%d",
+				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 3139f44..ab89db0 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);
@@ -605,6 +606,16 @@ asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
 				    size_t len);
 asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache);
 
+asmlinkage long sys_time_pps_cmd(int cmd, void __user *arg);
+asmlinkage long sys_time_pps_getparams(int source,
+					struct pps_params __user *params);
+asmlinkage long sys_time_pps_setparams(int source,
+					const struct pps_params __user *params);
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode);
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info,
+					const struct timespec __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 d7306d0..2bbd244 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -141,3 +141,10 @@ cond_syscall(compat_sys_migrate_pages);
 cond_syscall(sys_bdflush);
 cond_syscall(sys_ioprio_set);
 cond_syscall(sys_ioprio_get);
+
+/* 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);

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Tue, 2007-06-26 at 12:06 +0200, Rodolfo Giometti wrote:
> Hello,
> 
> here my new version of LinuxPPS with a new syscalls API.
> 
> Please take a look at this new patch and report any
> suggestions/modifications so I can prepare a proper patch for kernel
> inclusion.

Your syscalls blindly dereference userspace pointers instead of using
copy_{to,from} user.

Why did you split all your syscalls into two functions?

s/__FUNCTION__/__func__/

s/antennas/antennae/

You seem to have added debugging messages mentioning 'serial8250' into
serial_core.h

You added <linux/pps.h> with #ifdef __KERNEL__ in it, but didn't export
it to userspace. Why?

Your structures for userspace communication look OK -- I don't think you
need special 32/64 compatibility for them. You do need it for the
'struct timespec' in sys_time_pps_fetch() though.

Must we have the ioctl-like interface to sys_time_pps_cmd()? If the
second argument is always 'struct pps_source_data_s *', why does the
syscall pretend it's 'void *'?

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Tue, Jun 26, 2007 at 11:57:07AM +0100, David Woodhouse wrote:
> 
> Your syscalls blindly dereference userspace pointers instead of using
> copy_{to,from} user.

I use access_ok() to test userspace addresses. It should be ok,
shouldn't it?

> Why did you split all your syscalls into two functions?
> 
> s/__FUNCTION__/__func__/

Just for an easy management of mutex locking.

> s/antennas/antennae/

Done. However I found other files in the kernel code with the same
error... ;)

> You seem to have added debugging messages mentioning 'serial8250' into
> serial_core.h

Yes! Fixed.

> You added <linux/pps.h> with #ifdef __KERNEL__ in it, but didn't export
> it to userspace. Why?

This file is called by timepps.h who exports the userland data.

> Your structures for userspace communication look OK -- I don't think you
> need special 32/64 compatibility for them. You do need it for the
> 'struct timespec' in sys_time_pps_fetch() though.

Mmm... can you please explain a bit what do you mean? Maybe just a
link...

> Must we have the ioctl-like interface to sys_time_pps_cmd()? If the

It seems to me stronger then other solutions...

> second argument is always 'struct pps_source_data_s *', why does the
> syscall pretend it's 'void *'?

Just to keep sys_time_pps_cmd() generic for future new commands.

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Tue, 2007-06-26 at 19:06 +0200, Rodolfo Giometti wrote:
> On Tue, Jun 26, 2007 at 11:57:07AM +0100, David Woodhouse wrote:
> > 
> > Your syscalls blindly dereference userspace pointers instead of using
> > copy_{to,from} user.
> 
> I use access_ok() to test userspace addresses. It should be ok,
> shouldn't it?

No; it's racy. You must use copy_from_user() and copy_to_user().

> > Why did you split all your syscalls into two functions?
> > 
> > s/__FUNCTION__/__func__/
> 
> Just for an easy management of mutex locking.

That sounds like you're scared of using goto. Don't be :)

> > s/antennas/antennae/
> 
> Done. However I found other files in the kernel code with the same
> error... ;)

This is often true of anything which gets pointed out during review. :)

> > You seem to have added debugging messages mentioning 'serial8250' into
> > serial_core.h
> 
> Yes! Fixed.
> 
> > You added <linux/pps.h> with #ifdef __KERNEL__ in it, but didn't export
> > it to userspace. Why?
> 
> This file is called by timepps.h who exports the userland data.

I don't see this timepps.h of which you speak. If it's a _userspace_
file, it cannot include <linux/pps.h> unless you actually add
<linux/pps.h> to the list of files which are exported.

Run 'make headers_install' and observe that there is no file
usr/include/linux/pps.h -- so there would be no /usr/include/linux/pps.h
generated from your kernel tree. You need to add 'unifdef-y += pps.h' to
include/linux/Kbuild for that to happen.

> > Your structures for userspace communication look OK -- I don't think you
> > need special 32/64 compatibility for them. You do need it for the
> > 'struct timespec' in sys_time_pps_fetch() though.
> 
> Mmm... can you please explain a bit what do you mean? Maybe just a
> link...

64-bit kernels can run 32-bit userspace programs. But some structures
come out _differently_ between 32-bit and 64-bit compilation, so the
system call needs a special 'compat' handler instead of just running the
normal 64-bit system call.

The 'struct timespec' is one structure which is sometimes different for
32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
have a separate compat_sys_xxxx() to handle that. See something like
compat_sys_clock_settime() in kernel/compat.c for an example (but don't
use set_fs() like it does; just see how it handles the compat_timespec).

> > Must we have the ioctl-like interface to sys_time_pps_cmd()? If the
> 
> It seems to me stronger then other solutions...
> 
> > second argument is always 'struct pps_source_data_s *', why does the
> > syscall pretend it's 'void *'?
> 
> Just to keep sys_time_pps_cmd() generic for future new commands.

Hm. I'll let other people complain at you about that :)

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:

> That sounds like you're scared of using goto. Don't be :)

But it's not wrong... should I change it or not?

> I don't see this timepps.h of which you speak. If it's a _userspace_
> file, it cannot include <linux/pps.h> unless you actually add
> <linux/pps.h> to the list of files which are exported.
> 
> Run 'make headers_install' and observe that there is no file
> usr/include/linux/pps.h -- so there would be no /usr/include/linux/pps.h
> generated from your kernel tree. You need to add 'unifdef-y += pps.h' to
> include/linux/Kbuild for that to happen.

Is this right?

diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 94cc04a..87f1e2c 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -290,6 +290,7 @@ 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

> 64-bit kernels can run 32-bit userspace programs. But some structures
> come out _differently_ between 32-bit and 64-bit compilation, so the
> system call needs a special 'compat' handler instead of just running the
> normal 64-bit system call.
> 
> The 'struct timespec' is one structure which is sometimes different for
> 32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
> have a separate compat_sys_xxxx() to handle that. See something like
> compat_sys_clock_settime() in kernel/compat.c for an example (but don't
> use set_fs() like it does; just see how it handles the compat_timespec).

Ok, I'll take a look at it.

Thanks a lot,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Tue, 2007-06-26 at 20:13 +0200, Rodolfo Giometti wrote:
> On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:
> 
> > That sounds like you're scared of using goto. Don't be :)
> 
> But it's not wrong... should I change it or not?

I would suggest changing it. It makes it more obvious to the casual that
there are no other callers of the 'internal' functions. It's a matter of
taste though; if you feel _very_ strongly about it then feel free to
ignore me.

> Is this right?
> +unifdef-y += pps.h

Yes, that looks right. As a matter of course you should also run 'make
headers_check' before submitting your new patch, to make sure everything
is sane. That'll tell you if your exported pps.h is trying to include
other header files which aren't also exported.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:
> 
> 64-bit kernels can run 32-bit userspace programs. But some structures
> come out _differently_ between 32-bit and 64-bit compilation, so the
> system call needs a special 'compat' handler instead of just running the
> normal 64-bit system call.
> 
> The 'struct timespec' is one structure which is sometimes different for
> 32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
> have a separate compat_sys_xxxx() to handle that. See something like
> compat_sys_clock_settime() in kernel/compat.c for an example (but don't
> use set_fs() like it does; just see how it handles the compat_timespec).

Did you mean something like this?

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index befe292..3e401e5 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -26,6 +26,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <linux/sched.h>
+#include <linux/compat.h>
 #include <linux/pps.h>
 #include <asm/uaccess.h>
 
@@ -284,9 +285,15 @@ sys_time_pps_getcap_exit:
        return ret;
 }
 
+#ifdef CONFIG_COMPAT
 asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
-                                       struct pps_info __user *info, 
-                                       const struct timespec __user *timeout)
+                               struct pps_info __user *info, 
+                               const struct compat_timespec __user *timeout)
+#else
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+                               struct pps_info __user *info, 
+                               const struct timespec __user *timeout)
+#endif
 {
        unsigned long ticks;
        struct pps_info pi;
@@ -318,7 +325,11 @@ asmlinkage long sys_time_pps_fetch(int source, const int ts 
        /* Manage the timeout */
        if (timeout) {
+#ifdef CONFIG_COMPAT
+               ret = get_compat_timespec(&to, timeout);
+#else
                ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+#endif
                if (ret)
                        goto sys_time_pps_fetch_exit;
                if (to.tv_sec != -1) {

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Wed, 2007-06-27 at 12:14 +0200, Rodolfo Giometti wrote:
> On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:
> > 
> > 64-bit kernels can run 32-bit userspace programs. But some structures
> > come out _differently_ between 32-bit and 64-bit compilation, so the
> > system call needs a special 'compat' handler instead of just running the
> > normal 64-bit system call.
> > 
> > The 'struct timespec' is one structure which is sometimes different for
> > 32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
> > have a separate compat_sys_xxxx() to handle that. See something like
> > compat_sys_clock_settime() in kernel/compat.c for an example (but don't
> > use set_fs() like it does; just see how it handles the compat_timespec).
> 
> Did you mean something like this?

How will 64-bit system calls work if you do it like that? You need to
provide _both_ sys_time_pps_fetch() and compat_sys_time_pps_fetch().

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Wed, Jun 27, 2007 at 11:18:30AM +0100, David Woodhouse wrote:
> On Wed, 2007-06-27 at 12:14 +0200, Rodolfo Giometti wrote:
> > On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:
> > > 
> > > 64-bit kernels can run 32-bit userspace programs. But some structures
> > > come out _differently_ between 32-bit and 64-bit compilation, so the
> > > system call needs a special 'compat' handler instead of just running the
> > > normal 64-bit system call.
> > > 
> > > The 'struct timespec' is one structure which is sometimes different for
> > > 32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
> > > have a separate compat_sys_xxxx() to handle that. See something like
> > > compat_sys_clock_settime() in kernel/compat.c for an example (but don't
> > > use set_fs() like it does; just see how it handles the compat_timespec).
> > 
> > Did you mean something like this?
> 
> How will 64-bit system calls work if you do it like that? You need to
> provide _both_ sys_time_pps_fetch() and compat_sys_time_pps_fetch().

Sorry, I'm new to this 32/64 bits issues...

Now is it correct?

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index befe292..b9df17b 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -26,6 +26,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <linux/sched.h>
+#include <linux/compat.h>
 #include <linux/pps.h>
 #include <asm/uaccess.h>
 
@@ -362,6 +363,22 @@ sys_time_pps_fetch_exit:
        return ret;
 }
 
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_time_pps_fetch(int source, const int tsformat,
+                               struct pps_info __user *info, 
+                               const struct compat_timespec __user *timeout)
+{
+       int ret;
+       struct timespec to;
+
+       ret = get_compat_timespec(&to, timeout);
+       if (ret)
+               return -EFAULT;
+       
+       return sys_time_pps_fetch(source, tsformat, info, &to);
+}
+#endif
+
 /*
  * Module staff
  */

Since I have no way to test this code maybe is better add no function
at all and simply using a warning message if someone try compiling
this code with CONFIG_COMPAT enabled...

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Wed, 2007-06-27 at 14:58 +0200, Rodolfo Giometti wrote: 
> On Wed, Jun 27, 2007 at 11:18:30AM +0100, David Woodhouse wrote:
> > On Wed, 2007-06-27 at 12:14 +0200, Rodolfo Giometti wrote:
> > > On Tue, Jun 26, 2007 at 06:38:40PM +0100, David Woodhouse wrote:
> > > > 
> > > > 64-bit kernels can run 32-bit userspace programs. But some structures
> > > > come out _differently_ between 32-bit and 64-bit compilation, so the
> > > > system call needs a special 'compat' handler instead of just running the
> > > > normal 64-bit system call.
> > > > 
> > > > The 'struct timespec' is one structure which is sometimes different for
> > > > 32-bit vs. 64-bit, so any system call taking a 'struct timespec' must
> > > > have a separate compat_sys_xxxx() to handle that. See something like
> > > > compat_sys_clock_settime() in kernel/compat.c for an example (but don't
> > > > use set_fs() like it does; just see how it handles the compat_timespec).
> > > 
> > > Did you mean something like this?
> > 
> > How will 64-bit system calls work if you do it like that? You need to
> > provide _both_ sys_time_pps_fetch() and compat_sys_time_pps_fetch().
> 
> Sorry, I'm new to this 32/64 bits issues...
> 
> Now is it correct?

No, because you're passing a _kernel_ pointer to sys_time_pps_fetch()
where it expects a userspace pointer. Use compat_alloc_user_space() to
find somewhere to put it in user space, instead. Or change your internal
__sys_time_pps_fetch() function to take a number of ticks instead of a
pointer to a timespec, then call that directly with appropriate
arguments, from both the normal and compat syscall routines.
> 
> Since I have no way to test this code maybe is better add no function
> at all and simply using a warning message if someone try compiling
> this code with CONFIG_COMPAT enabled...

No. The fact that you cannot test it is no excuse for submitting
something which is _known_ to be broken. Once you have it to the point
where a casual observer can't point out errors, then people can test it
for you.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

[-- Attachment #1: Type: text/plain, Size: 812 bytes --]

On Wed, Jun 27, 2007 at 05:11:00PM +0100, David Woodhouse wrote:

> No, because you're passing a _kernel_ pointer to sys_time_pps_fetch()
> where it expects a userspace pointer. Use compat_alloc_user_space() to
> find somewhere to put it in user space, instead. Or change your internal
> __sys_time_pps_fetch() function to take a number of ticks instead of a
> pointer to a timespec, then call that directly with appropriate
> arguments, from both the normal and compat syscall routines.

Ok. Please see the attached patch.

Thanks a lot,

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

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 2818 bytes --]

diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index befe292..820cc9a 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -26,6 +26,7 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 #include <linux/sched.h>
+#include <linux/compat.h>
 #include <linux/pps.h>
 #include <asm/uaccess.h>
 
@@ -284,13 +285,12 @@ sys_time_pps_getcap_exit:
 	return ret;
 }
 
-asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+static long __sys_time_pps_fetch(int source, const int tsformat,
 					struct pps_info __user *info, 
-					const struct timespec __user *timeout)
+					const struct timespec *timeout)
 {
 	unsigned long ticks;
 	struct pps_info pi;
-	struct timespec to;
 	int ret;
 
 	pps_dbg("%s: source %d", __FUNCTION__, source);
@@ -317,24 +317,19 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
 	pps_source[source].go = 0;
 
  	/* Manage the timeout */
-	if (timeout) {
-		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
-		if (ret)
-			goto sys_time_pps_fetch_exit;
-		if (to.tv_sec != -1) {
-			pps_dbg("timeout %ld.%09ld", to.tv_sec, to.tv_nsec);
-			ticks = to.tv_sec * HZ;
-			ticks += to.tv_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) {
-					pps_dbg("timeout expired");
-					ret = -ETIMEDOUT;
-					goto sys_time_pps_fetch_exit;
-				}
+	if (timeout->tv_sec != -1) {
+		pps_dbg("timeout %ld.%09ld", timeout->tv_sec, timeout->tv_nsec);
+		ticks = timeout->tv_sec * HZ;
+		ticks += timeout->tv_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) {
+				pps_dbg("timeout expired");
+				ret = -ETIMEDOUT;
+				goto sys_time_pps_fetch_exit;
 			}
 		}
  	} else
@@ -362,6 +357,44 @@ sys_time_pps_fetch_exit:
 	return ret;
 }
 
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+		if (ret)
+			return ret;
+	}
+	else
+		to.tv_sec = -1;	
+
+	return __sys_time_pps_fetch(source, tsformat, info, timeout);
+}
+
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_time_pps_fetch(int source, const int tsformat,
+				struct pps_info __user *info, 
+				const struct compat_timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = get_compat_timespec(&to, timeout);
+		if (ret)
+			return -EFAULT;
+	}
+	else
+		to.tv_sec = -1;	
+	
+	return __sys_time_pps_fetch(source, tsformat, info, &to);
+}
+#endif
+
 /*
  * Module staff
  */

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Wed, 2007-06-27 at 19:45 +0200, Rodolfo Giometti wrote:
> Ok. Please see the attached patch.

Looks better. All I can find to complain about is the fact that you
return whatever copy_from_user() returns. Don't -- that's the number of
bytes left to copy. It should be if (copy_from_user(..)) return -EFAULT;


-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Wed, Jun 27, 2007 at 06:49:48PM +0100, David Woodhouse wrote:
> 
> Looks better. All I can find to complain about is the fact that you
> return whatever copy_from_user() returns. Don't -- that's the number of
> bytes left to copy. It should be if (copy_from_user(..)) return -EFAULT;

Ok, I'll fix it.

Just last question: I still don't well understand where I should
declare the new compat_sys_time_pps_fetch() syscall... it's
automagically defined by the system when CONFIG_COMPAT is enabled? :-o

Thanks for your help,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Thu, 2007-06-28 at 00:46 +0200, Rodolfo Giometti wrote:
> Just last question: I still don't well understand where I should
> declare the new compat_sys_time_pps_fetch() syscall... it's
> automagically defined by the system when CONFIG_COMPAT is enabled? :-o

It isn't used on i386. On a 64-bit architecture, you need to put
compat_sys_time_pps_fetch() into the syscall table for 32-bit
processes. 

On PowerPC you do this by using COMPAT_SYS_SPU(time_pps_fetch) instead
of SYSCALL_SPU(..) in include/asm-powerpc/systbl.h. On x86_64 you'd put
it into the ia32_sys_call_table in arch/x86_64/ia32/ia32entry.S

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Thu, Jun 28, 2007 at 09:08:53AM +0100, David Woodhouse wrote:
> On Thu, 2007-06-28 at 00:46 +0200, Rodolfo Giometti wrote:
> > Just last question: I still don't well understand where I should
> > declare the new compat_sys_time_pps_fetch() syscall... it's
> > automagically defined by the system when CONFIG_COMPAT is enabled? :-o
> 
> It isn't used on i386. On a 64-bit architecture, you need to put
> compat_sys_time_pps_fetch() into the syscall table for 32-bit
> processes. 
> 
> On PowerPC you do this by using COMPAT_SYS_SPU(time_pps_fetch) instead
> of SYSCALL_SPU(..) in include/asm-powerpc/systbl.h. On x86_64 you'd put
> it into the ia32_sys_call_table in arch/x86_64/ia32/ia32entry.S

I see.

Do you think I should add these functions into my patch, even if I
cannot test it, or it's enought providing just the
compat_sys_time_pps_fetch() function?

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Thu, 2007-06-28 at 10:15 +0200, Rodolfo Giometti wrote:
> Do you think I should add these functions into my patch, even if I
> cannot test it, or it's enought providing just the
> compat_sys_time_pps_fetch() function? 

Probably best to put them in. That way, you make it easier for people to
test. Ideally, you should also provide a simple program that other
people can use to test it, preferably without needing hardware (or at
least just a nullmodem cable and another test program at the other end
of it).

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Thu, Jun 28, 2007 at 09:31:14AM +0100, David Woodhouse wrote:
> On Thu, 2007-06-28 at 10:15 +0200, Rodolfo Giometti wrote:
> > Do you think I should add these functions into my patch, even if I
> > cannot test it, or it's enought providing just the
> > compat_sys_time_pps_fetch() function? 
> 
> Probably best to put them in. That way, you make it easier for people to

Mmm... so I should provide new syscalls for _all_
architectures... gulp! :)

It could be acceptable, just for the first release, to provide the
support for x86 only?

In this manner we can have a first release of LinuxPPS in the main
line just for x86 and then me, or other people, may add support for
the several supported architectures.

> test. Ideally, you should also provide a simple program that other
> people can use to test it, preferably without needing hardware (or at
> least just a nullmodem cable and another test program at the other end
> of it).

I already have a basic testing program... I can add it into
Documentation/pps directory, can't I?

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API)

[David Woodhouse]

On Thu, 2007-06-28 at 10:40 +0200, Rodolfo Giometti wrote:
> On Thu, Jun 28, 2007 at 09:31:14AM +0100, David Woodhouse wrote:
> > On Thu, 2007-06-28 at 10:15 +0200, Rodolfo Giometti wrote:
> > > Do you think I should add these functions into my patch, even if I
> > > cannot test it, or it's enought providing just the
> > > compat_sys_time_pps_fetch() function? 
> > 
> > Probably best to put them in. That way, you make it easier for people to
> 
> Mmm... so I should provide new syscalls for _all_
> architectures... gulp! :)

It's nice if you can do so, but I wouldn't suggest that you _have_ to.
I have to admit that I rarely bother actually wiring new system calls up
on anything but PowerPC to start with.

The important thing is that you've _considered_ the other architectures,
and the 32/64 compatibility implications. As long as the API of your new
system call is sensible and takes that kind of thing into account, it
should be fine.

Had you considered changing the API so that you don't need the
compatibility wrapper at all? Could you take an integer number of µS or
ms instead of a struct timespec?

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API)

[Rodolfo Giometti]

On Thu, Jun 28, 2007 at 12:44:20PM +0100, David Woodhouse wrote:
> 
> It's nice if you can do so, but I wouldn't suggest that you _have_ to.
> I have to admit that I rarely bother actually wiring new system calls up
> on anything but PowerPC to start with.
> 
> The important thing is that you've _considered_ the other architectures,
> and the 32/64 compatibility implications. As long as the API of your new
> system call is sensible and takes that kind of thing into account, it
> should be fine.

Ok. :)

> Had you considered changing the API so that you don't need the
> compatibility wrapper at all? Could you take an integer number of µS or
> ms instead of a struct timespec?

Not before now, but I followed the API specified into RFC 2783 who
specifies struct timespec...

Thanks for your suggestions! I'll send a new patch ASAP!

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

[PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

[-- Attachment #1: Type: text/plain, Size: 428 bytes --]

Hello,

here my new LinuxPPS patch.

What to do now for kernel inclusion? Should I provide several patches?
If so how should I divide them?

Thanks a lot,

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

[-- Attachment #2: ntp-pps-2.6.21-new_API.diff --]
[-- Type: text/x-diff, Size: 67179 bytes --]

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..0617ea4
--- /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 Documentaion/pps/).
\ No newline at end of file
diff --git a/Documentation/pps/ppsctl.c b/Documentation/pps/ppsctl.c
new file mode 100644
index 0000000..e6ab2b9
--- /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..efbe28f
--- /dev/null
+++ b/Documentation/pps/ppstest.c
@@ -0,0 +1,199 @@
+#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..d690aa6
--- /dev/null
+++ b/Documentation/pps/timepps.h
@@ -0,0 +1,161 @@
+/*
+ * 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>
+
+/* --- 3.2 New data structures --------------------------------------------- */
+
+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
+
+/* --- 3.4 Functions ------------------------------------------------------- */
+
+/*
+ * 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';
+	return;
+}
+
+#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)
+		return -EINVAL;
+
+	/* 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)
+{
+	return syscall(__NR_time_pps_getparams, handle, ppsparams);
+}
+
+int time_pps_setparams(pps_handle_t handle,
+				const pps_params_t *ppsparams)
+{
+	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)
+{
+	return syscall(__NR_time_pps_fetch, handle,
+				tsformat, ppsinfobuf, timeout);
+}
+
+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 */
+	return -EOPNOTSUPP;
+}
+
+#endif   /* _SYS_TIMEPPS_H_ */
diff --git a/MAINTAINERS b/MAINTAINERS
index cfd26dd..dd6784d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2860,6 +2860,13 @@ 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 0772678..ae1df31 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -320,3 +320,8 @@ ENTRY(sys_call_table)
 	.long sys_getcpu
 	.long sys_epoll_pwait
 	.long sys_utimensat		/* 320 */
+	.long sys_time_pps_cmd
+	.long sys_time_pps_getparams
+	.long sys_time_pps_setparams
+	.long sys_time_pps_getcap
+	.long sys_time_pps_fetch	/* 325 */
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 26ca903..97dc041 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -59,6 +59,7 @@ 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..a50b336 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 +838,35 @@ 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) 
+			pps_err("cannot register PPS source \"%s\"",
+					port->pps_info.path);	
+		else
+			pps_info("PPS source #%d \"%s\" added to the system",
+					port->pps_source, port->pps_info.path);
+	} else {
+		port->pps_source = -1;
+		pps_err("PPS support disabled due port \"%s\" is in polling mode",
+			port->pps_info.path);
+	}
+#endif
+
 	return 0;
 }
 
@@ -860,6 +910,14 @@ 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));
+		pps_dbg("PPS source #%d \"%s\" removed from the system",
+			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..1d16f14
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,34 @@
+#
+# Character device 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.
+
+	  This PPS support can also be built as a module.  If so, the module
+	  will be called pps-core.
+
+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..76101cd
--- /dev/null
+++ b/drivers/pps/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the PPS core.
+#
+
+pps_core-objs			+= pps.o kapi.o sysfs.o
+obj-$(CONFIG_PPS)		+= pps_core.o
+obj-y				+= clients/
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
new file mode 100644
index 0000000..867df3a
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,30 @@
+#
+# LinuxPPS clients configuration
+#
+
+if PPS
+
+comment "PPS clients support"
+
+config PPS_CLIENT_KTIMER
+	tristate "Kernel timer client (Testing client, use for debug)"
+	help
+	  If you say yes here you get support for a PPS debugging client
+	  which uses a kernel timer to generate the PPS signal.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ktimer.o.
+
+config PPS_CLIENT_UART
+	bool "UART serial support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the CD (Carrier Detect) pin of your serial port.
+
+config PPS_CLIENT_LP
+	bool "Parallel printer support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the interrupt pin of your parallel port.
+
+endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
new file mode 100644
index 0000000..3ecca41
--- /dev/null
+++ b/drivers/pps/clients/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for miscellaneous I2C chip drivers.
+#
+
+obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= ktimer.o
+
diff --git a/drivers/pps/clients/ktimer.c b/drivers/pps/clients/ktimer.c
new file mode 100644
index 0000000..e9e5c47
--- /dev/null
+++ b/drivers/pps/clients/ktimer.c
@@ -0,0 +1,113 @@
+/*
+ * 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)
+{
+	pps_info("PPS event at %lu", 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)
+{
+	pps_info("echo %s %s for source %d",
+		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);
+
+	pps_info("ktimer PPS source unregistered");
+}
+
+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) {
+		pps_err("cannot register ktimer source");
+		return ret;
+	}
+	source = ret;
+
+	setup_timer(&ktimer, pps_ktimer_event, 0);
+	mod_timer(&ktimer, jiffies + HZ);
+
+	pps_info("ktimer PPS source registered at %d", source);
+
+	return  0;
+}
+
+module_init(pps_ktimer_init);
+module_exit(pps_ktimer_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("testing 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..dd24c31
--- /dev/null
+++ b/drivers/pps/kapi.c
@@ -0,0 +1,202 @@
+/*
+ * 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/pps.h>
+
+/* 
+ * Local functions
+ */
+
+static void pps_add_offset(struct timespec *ts, struct timespec *offset)
+{
+	ts->tv_nsec += offset->tv_nsec;
+	if (ts->tv_nsec >= NSEC_PER_SEC) {
+		ts->tv_nsec -= NSEC_PER_SEC;
+		ts->tv_sec++;
+	} else if (ts->tv_nsec < 0) {
+		ts->tv_nsec += NSEC_PER_SEC;
+		ts->tv_sec--;
+	}
+	ts->tv_sec += offset->tv_sec;
+}
+
+/*
+ * Exported functions
+ */
+
+static int __pps_register_source(struct pps_source_info_s *info,
+				int default_params, int try_id)
+{
+	int i;
+
+	if (try_id >= 0) {
+		if (pps_is_allocated(try_id)) {
+			pps_err("source id %d busy", try_id);
+			return -EBUSY;
+		}
+		i = try_id;
+	} else {
+		for (i = 0; i < PPS_MAX_SOURCES; i++)
+			if (!pps_is_allocated(i))
+				break;
+		if (i >= PPS_MAX_SOURCES) {
+			pps_err("no free source ids");
+			return -ENOMEM;
+		}
+	}
+
+	/* Sanity checks */
+	if ((info->mode & default_params) != default_params) {
+		pps_err("unsupported default parameters");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0 &&
+			info->echo == NULL) {
+		pps_err("echo function is not defined");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_TSFMT_TSPEC|PPS_TSFMT_NTPFP)) == 0) {
+		pps_err("unspecified time format");
+		return -EINVAL;
+	}
+
+	/* Allocate the PPS source.
+	 *
+	 * Note that we should reset all fields BUT "info" one! */
+	memset(&(pps_source[i].params), 0, sizeof(struct pps_params));
+	pps_source[i].params.api_version = PPS_API_VERS;
+	pps_source[i].params.mode = default_params;
+	pps_source[i].assert_sequence = 0;
+	pps_source[i].clear_sequence = 0;
+	pps_source[i].current_mode = 0;
+	pps_source[i].go = 0;
+	init_waitqueue_head(&pps_source[i].queue);
+
+	/* Allocate the PPS source */
+	pps_source[i].info = info;
+
+	return i;
+}
+
+int pps_register_source(struct pps_source_info_s *info, int default_params,
+			int try_id)
+{
+	int i, ret;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __pps_register_source(info, default_params, try_id);
+	mutex_unlock(&pps_mutex);
+
+	if (ret < 0)
+		return ret;
+	i = ret;
+
+	ret = pps_sysfs_create_source_entry(info, i);
+	if (ret < 0)
+		pps_err("unable to create sysfs entry for source %d", i);
+
+	return i;
+}
+EXPORT_SYMBOL(pps_register_source);
+
+static void __pps_unregister_source(struct pps_source_info_s *info)
+{  
+	int i;
+
+	for (i = 0; i < PPS_MAX_SOURCES; i++)
+		if (pps_is_allocated(i) && pps_source[i].info == info)
+			break;
+
+	if (i >= PPS_MAX_SOURCES) {
+		pps_err("warning! Try to unregister an unknow PPS source");
+		return;
+	}
+
+	/* Deallocate the PPS source */
+	pps_source[i].info = &dummy_info; 
+} 
+
+void pps_unregister_source(struct pps_source_info_s *info)
+{
+
+	pps_sysfs_remove_source_entry(info);
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return;
+	__pps_unregister_source(info);
+	mutex_unlock(&pps_mutex);
+}
+EXPORT_SYMBOL(pps_unregister_source);
+
+void pps_event(int source, int event, void *data)
+{
+	struct timespec ts;
+
+	/* First of all we get the time stamp... */
+	getnstimeofday(&ts);
+
+	if ((event & (PPS_CAPTUREASSERT|PPS_CAPTURECLEAR)) == 0 ) {
+		pps_err("unknow event (%x) for source %d", event, source);
+		return;
+	}
+
+	/* Must call the echo function? */
+	if ((pps_source[source].params.mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0)
+		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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].assert_tu.tspec = ts;
+		pps_source[source].assert_sequence++;
+		pps_dbg("capture assert seq #%lu for source %d", 
+			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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].clear_tu.tspec = ts;
+		pps_source[source].clear_sequence++;
+		pps_dbg("capture clear seq #%lu for source %d", 
+			pps_source[source].clear_sequence, source);
+	}
+
+	pps_source[source].go = ~0;
+	wake_up_interruptible(&pps_source[source].queue);
+}
+EXPORT_SYMBOL(pps_event);
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 0000000..5907c94
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,451 @@
+/*
+ * 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/compat.h>
+#include <linux/pps.h>
+#include <asm/uaccess.h>
+
+/*
+ * Global variables
+ */
+
+struct pps_s pps_source[PPS_MAX_SOURCES];
+DEFINE_MUTEX(pps_mutex);
+
+void dummy_echo(int source, int event, void *data) { }
+struct pps_source_info_s dummy_info;	/* Dummy PPS info for unallocated
+					   PPS sources */
+
+/*
+ * 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;
+
+	pps_dbg("%s: cmd %d", __FUNCTION__, cmd);
+
+	/* Sanity checks */
+	if (_IOC_TYPE(cmd) != 'P')
+		return -EOPNOTSUPP;
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		ret = !access_ok(VERIFY_WRITE, arg, _IOC_SIZE(cmd));
+	else if (_IOC_DIR(cmd) & _IOC_WRITE)
+		ret = !access_ok(VERIFY_READ, arg, _IOC_SIZE(cmd));
+	if (ret)
+		return -EFAULT;
+
+	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;
+		}
+
+		pps_dbg("PPS_CMD_FIND_SRC: source %d", data.source);
+
+		data.source = pps_find_source(data.source);
+		if (data.source < 0) {
+			pps_dbg("no PPS devices found");
+			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;
+		}
+
+		pps_dbg("PPS_CMD_FIND_PATH: path %s", data.path);
+
+		data.source = pps_find_path(data.path);
+		if (data.source < 0) {
+			pps_dbg("no PPS devices found");
+			ret = -ENODEV;
+			goto sys_time_pps_cmd_exit;
+	 	}
+
+		break;
+
+	default :
+		pps_err("invalid sys_time_pps_cmd %d", 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_params __user *params)
+{
+	int ret = 0;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, params, sizeof(struct pps_params)))
+		return -EFAULT;
+
+	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_params));
+	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_params __user *params)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Check the capabilities */
+	if (!capable(CAP_SYS_TIME))
+		return -EPERM;
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_READ, params, sizeof(struct pps_params)))
+		return -EFAULT;
+	if ((params->mode & ~pps_source[source].info->mode) != 0) {
+		pps_dbg("unsupported capabilities");
+		return -EINVAL;
+ 	}
+	if ((params->mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
+		pps_dbg("capture mode unspecified");
+		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_params));
+	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 */
+		pps_dbg("time format unspecified");
+		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;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!mode)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, mode, sizeof(int)))
+		return -EFAULT;
+
+	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;
+}
+
+static long __sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec *timeout)
+{
+	unsigned long ticks;
+	struct pps_info pi;
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (tsformat != PPS_TSFMT_TSPEC) {
+		pps_dbg("unsupported time format");
+		return -EINVAL;
+ 	}
+	if (!info)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, info, sizeof(struct pps_info)))
+		return -EFAULT;
+
+	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->tv_sec != -1) {
+		pps_dbg("timeout %ld.%09ld", timeout->tv_sec, timeout->tv_nsec);
+		ticks = timeout->tv_sec * HZ;
+		ticks += timeout->tv_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) {
+				pps_dbg("timeout expired");
+				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) {
+		pps_dbg("pending signal caught");
+		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_info));
+	if (ret)
+		ret = -EFAULT;
+
+sys_time_pps_fetch_exit:
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+		if (ret)
+			return ret;
+	}
+	else
+		to.tv_sec = -1;	
+
+	return __sys_time_pps_fetch(source, tsformat, info, timeout);
+}
+
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_time_pps_fetch(int source, const int tsformat,
+				struct pps_info __user *info, 
+				const struct compat_timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = get_compat_timespec(&to, timeout);
+		if (ret)
+			return -EFAULT;
+	}
+	else
+		to.tv_sec = -1;	
+	
+	return __sys_time_pps_fetch(source, tsformat, info, &to);
+}
+#endif
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_exit(void)
+{
+	pps_sysfs_unregister();
+
+	pps_info("LinuxPPS API ver. %d removed", PPS_API_VERS);
+}
+
+static int __init pps_init(void)
+{
+	int i, ret;
+
+	/* Init pps_source info */
+	dummy_info.echo = dummy_echo;
+	for (i = 0; i < PPS_MAX_SOURCES; i++) {
+		pps_source[i].info = &dummy_info;
+		init_waitqueue_head(&pps_source[i].queue);
+	}
+
+	/* Register to sysfs */
+	ret = pps_sysfs_register();
+	if (ret < 0) {
+		pps_err("unable to register sysfs");
+		return ret;
+	}
+
+	pps_info("LinuxPPS API ver. %d registered", PPS_API_VERS);
+	pps_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+		"<giometti@linux.it>", 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..0dae24b
--- /dev/null
+++ b/drivers/pps/sysfs.c
@@ -0,0 +1,219 @@
+/*
+ * 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, "%ld.%09ld#%ld\n",
+			dev->assert_tu.tspec.tv_sec,
+			dev->assert_tu.tspec.tv_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, "%ld.%09ld#%ld\n",
+			dev->clear_tu.tspec.tv_sec,
+			dev->clear_tu.tspec.tv_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 48e259a..3e6ed91 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..4a9906f 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 +634,52 @@ 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) {
+		pps_err("cannot register PPS source \"%s\"", state->pps_info.path);
+		return ret;
+	}
+	port->pps_source = ret;
+	pps_info("PPS source #%d \"%s\" added to the system ",
+		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);
+	pps_dbg("PPS source #%d \"%s\" removed from the system",
+	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 +854,19 @@ 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 +2155,12 @@ 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 +2410,12 @@ 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 bd21e79..b3e7a31 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -326,10 +326,15 @@
 #define __NR_getcpu		318
 #define __NR_epoll_pwait	319
 #define __NR_utimensat		320
+#define __NR_time_pps_cmd	321
+#define __NR_time_pps_getparams	322
+#define __NR_time_pps_setparams	323
+#define __NR_time_pps_getcap	324
+#define __NR_time_pps_fetch	325
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 321
+#define NR_syscalls 326
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 94cc04a..87f1e2c 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -290,6 +290,7 @@ 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..f53d9f4 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);
+	pps_dbg("parport_pc: PPS assert event at %lu on source #%d",
+		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..6b53864
--- /dev/null
+++ b/include/linux/pps.h
@@ -0,0 +1,211 @@
+/*
+ * 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 <asm/types.h>
+#include <sys/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
+
+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 */
+};
+
+/*
+ * 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-rc2"
+
+#ifdef CONFIG_PPS_DEBUG
+#define pps_dbg(format, arg...) printk(KERN_DEBUG "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#else
+#define pps_dbg(format, arg...) do {} while (0)
+#endif
+
+#define pps_err(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#define pps_info(format, arg...) printk(KERN_INFO "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+
+/*
+ * 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);/* the 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_params params;		/* PPS's current params */
+
+	volatile unsigned long assert_sequence;	/* PPS' assert event seq # */
+	volatile unsigned long clear_sequence;	/* PPS' clear event seq # */
+	volatile union pps_timeu assert_tu;
+	volatile union pps_timeu 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;
+extern struct pps_source_info_s dummy_info;
+
+/*
+ * Global functions
+ */
+
+static inline int pps_is_allocated(int source)
+{
+	return pps_source[source].info != &dummy_info;
+}
+
+#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 aa2653a..3638c68 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -148,6 +148,7 @@
 #include <linux/sched.h>
 #include <linux/tty.h>
 #include <linux/mutex.h>
+#include <linux/pps.h>
 
 struct uart_port;
 struct uart_info;
@@ -227,6 +228,9 @@ 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)
@@ -271,7 +275,8 @@ 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 */
@@ -303,6 +308,10 @@ 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;
 };
 
@@ -467,13 +476,27 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status)
 {
 	struct uart_info *info = port->info;
 
-	port->icount.dcd++;
+#ifdef CONFIG_PPS_CLIENT_UART
+	struct tty_driver *drv = port->info->tty->driver;
 
-#ifdef CONFIG_HARD_PPS
-	if ((port->flags & UPF_HARDPPS_CD) && status)
-		hardpps();
+	if (port->flags & UPF_HARDPPS_CD) {
+		if (status) {
+			pps_event(port->pps_source, PPS_CAPTUREASSERT, port);
+			pps_dbg("%s%d: PPS assert event at %lu on source #%d",
+				drv->driver_name, port->line,
+				jiffies, port->pps_source);
+		}
+		else {
+			pps_event(port->pps_source, PPS_CAPTURECLEAR, port);
+			pps_dbg("%s%d: PPS clear event at %lu on source #%d",
+				drv->driver_name, port->line,
+				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 3139f44..ab89db0 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);
@@ -605,6 +606,16 @@ asmlinkage long sys_set_robust_list(struct robust_list_head __user *head,
 				    size_t len);
 asmlinkage long sys_getcpu(unsigned __user *cpu, unsigned __user *node, struct getcpu_cache __user *cache);
 
+asmlinkage long sys_time_pps_cmd(int cmd, void __user *arg);
+asmlinkage long sys_time_pps_getparams(int source,
+					struct pps_params __user *params);
+asmlinkage long sys_time_pps_setparams(int source,
+					const struct pps_params __user *params);
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode);
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info,
+					const struct timespec __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 d7306d0..2bbd244 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -141,3 +141,10 @@ cond_syscall(compat_sys_migrate_pages);
 cond_syscall(sys_bdflush);
 cond_syscall(sys_ioprio_set);
 cond_syscall(sys_ioprio_get);
+
+/* 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);

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Thu, 2007-06-28 at 18:14 +0200, Rodolfo Giometti wrote:
> here my new LinuxPPS patch.
> 
> What to do now for kernel inclusion? Should I provide several patches?
> If so how should I divide them? 

It doesn't apply to the current git tree, which has already had some new
system calls added.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

[-- Attachment #1: Type: text/plain, Size: 492 bytes --]

On Fri, Jun 29, 2007 at 12:38:02PM +0100, David Woodhouse wrote:
> 
> It doesn't apply to the current git tree, which has already had some new
> system calls added.

Ok, here the patch against latest git commit.

Ciao,

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

[-- Attachment #2: ntp-pps-2.6.22-rc6-new_API.diff --]
[-- Type: text/x-diff, Size: 67110 bytes --]

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..0617ea4
--- /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 Documentaion/pps/).
\ No newline at end of file
diff --git a/Documentation/pps/ppsctl.c b/Documentation/pps/ppsctl.c
new file mode 100644
index 0000000..e6ab2b9
--- /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..efbe28f
--- /dev/null
+++ b/Documentation/pps/ppstest.c
@@ -0,0 +1,199 @@
+#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..d690aa6
--- /dev/null
+++ b/Documentation/pps/timepps.h
@@ -0,0 +1,161 @@
+/*
+ * 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>
+
+/* --- 3.2 New data structures --------------------------------------------- */
+
+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
+
+/* --- 3.4 Functions ------------------------------------------------------- */
+
+/*
+ * 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';
+	return;
+}
+
+#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)
+		return -EINVAL;
+
+	/* 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)
+{
+	return syscall(__NR_time_pps_getparams, handle, ppsparams);
+}
+
+int time_pps_setparams(pps_handle_t handle,
+				const pps_params_t *ppsparams)
+{
+	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)
+{
+	return syscall(__NR_time_pps_fetch, handle,
+				tsformat, ppsinfobuf, timeout);
+}
+
+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 */
+	return -EOPNOTSUPP;
+}
+
+#endif   /* _SYS_TIMEPPS_H_ */
diff --git a/MAINTAINERS b/MAINTAINERS
index 4ce895a..3450470 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..a50b336 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 +838,35 @@ 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) 
+			pps_err("cannot register PPS source \"%s\"",
+					port->pps_info.path);	
+		else
+			pps_info("PPS source #%d \"%s\" added to the system",
+					port->pps_source, port->pps_info.path);
+	} else {
+		port->pps_source = -1;
+		pps_err("PPS support disabled due port \"%s\" is in polling mode",
+			port->pps_info.path);
+	}
+#endif
+
 	return 0;
 }
 
@@ -860,6 +910,14 @@ 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));
+		pps_dbg("PPS source #%d \"%s\" removed from the system",
+			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..1d16f14
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,34 @@
+#
+# Character device 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.
+
+	  This PPS support can also be built as a module.  If so, the module
+	  will be called pps-core.
+
+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..76101cd
--- /dev/null
+++ b/drivers/pps/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the PPS core.
+#
+
+pps_core-objs			+= pps.o kapi.o sysfs.o
+obj-$(CONFIG_PPS)		+= pps_core.o
+obj-y				+= clients/
diff --git a/drivers/pps/clients/Kconfig b/drivers/pps/clients/Kconfig
new file mode 100644
index 0000000..867df3a
--- /dev/null
+++ b/drivers/pps/clients/Kconfig
@@ -0,0 +1,30 @@
+#
+# LinuxPPS clients configuration
+#
+
+if PPS
+
+comment "PPS clients support"
+
+config PPS_CLIENT_KTIMER
+	tristate "Kernel timer client (Testing client, use for debug)"
+	help
+	  If you say yes here you get support for a PPS debugging client
+	  which uses a kernel timer to generate the PPS signal.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ktimer.o.
+
+config PPS_CLIENT_UART
+	bool "UART serial support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the CD (Carrier Detect) pin of your serial port.
+
+config PPS_CLIENT_LP
+	bool "Parallel printer support"
+	help
+	  If you say yes here you get support for a PPS source connected
+	  with the interrupt pin of your parallel port.
+
+endif
diff --git a/drivers/pps/clients/Makefile b/drivers/pps/clients/Makefile
new file mode 100644
index 0000000..3ecca41
--- /dev/null
+++ b/drivers/pps/clients/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for miscellaneous I2C chip drivers.
+#
+
+obj-$(CONFIG_PPS_CLIENT_KTIMER)	+= ktimer.o
+
diff --git a/drivers/pps/clients/ktimer.c b/drivers/pps/clients/ktimer.c
new file mode 100644
index 0000000..e9e5c47
--- /dev/null
+++ b/drivers/pps/clients/ktimer.c
@@ -0,0 +1,113 @@
+/*
+ * 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)
+{
+	pps_info("PPS event at %lu", 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)
+{
+	pps_info("echo %s %s for source %d",
+		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);
+
+	pps_info("ktimer PPS source unregistered");
+}
+
+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) {
+		pps_err("cannot register ktimer source");
+		return ret;
+	}
+	source = ret;
+
+	setup_timer(&ktimer, pps_ktimer_event, 0);
+	mod_timer(&ktimer, jiffies + HZ);
+
+	pps_info("ktimer PPS source registered at %d", source);
+
+	return  0;
+}
+
+module_init(pps_ktimer_init);
+module_exit(pps_ktimer_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("testing 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..dd24c31
--- /dev/null
+++ b/drivers/pps/kapi.c
@@ -0,0 +1,202 @@
+/*
+ * 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/pps.h>
+
+/* 
+ * Local functions
+ */
+
+static void pps_add_offset(struct timespec *ts, struct timespec *offset)
+{
+	ts->tv_nsec += offset->tv_nsec;
+	if (ts->tv_nsec >= NSEC_PER_SEC) {
+		ts->tv_nsec -= NSEC_PER_SEC;
+		ts->tv_sec++;
+	} else if (ts->tv_nsec < 0) {
+		ts->tv_nsec += NSEC_PER_SEC;
+		ts->tv_sec--;
+	}
+	ts->tv_sec += offset->tv_sec;
+}
+
+/*
+ * Exported functions
+ */
+
+static int __pps_register_source(struct pps_source_info_s *info,
+				int default_params, int try_id)
+{
+	int i;
+
+	if (try_id >= 0) {
+		if (pps_is_allocated(try_id)) {
+			pps_err("source id %d busy", try_id);
+			return -EBUSY;
+		}
+		i = try_id;
+	} else {
+		for (i = 0; i < PPS_MAX_SOURCES; i++)
+			if (!pps_is_allocated(i))
+				break;
+		if (i >= PPS_MAX_SOURCES) {
+			pps_err("no free source ids");
+			return -ENOMEM;
+		}
+	}
+
+	/* Sanity checks */
+	if ((info->mode & default_params) != default_params) {
+		pps_err("unsupported default parameters");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0 &&
+			info->echo == NULL) {
+		pps_err("echo function is not defined");
+		return -EINVAL;
+	}
+	if ((info->mode & (PPS_TSFMT_TSPEC|PPS_TSFMT_NTPFP)) == 0) {
+		pps_err("unspecified time format");
+		return -EINVAL;
+	}
+
+	/* Allocate the PPS source.
+	 *
+	 * Note that we should reset all fields BUT "info" one! */
+	memset(&(pps_source[i].params), 0, sizeof(struct pps_params));
+	pps_source[i].params.api_version = PPS_API_VERS;
+	pps_source[i].params.mode = default_params;
+	pps_source[i].assert_sequence = 0;
+	pps_source[i].clear_sequence = 0;
+	pps_source[i].current_mode = 0;
+	pps_source[i].go = 0;
+	init_waitqueue_head(&pps_source[i].queue);
+
+	/* Allocate the PPS source */
+	pps_source[i].info = info;
+
+	return i;
+}
+
+int pps_register_source(struct pps_source_info_s *info, int default_params,
+			int try_id)
+{
+	int i, ret;
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return -EINTR;
+	ret = __pps_register_source(info, default_params, try_id);
+	mutex_unlock(&pps_mutex);
+
+	if (ret < 0)
+		return ret;
+	i = ret;
+
+	ret = pps_sysfs_create_source_entry(info, i);
+	if (ret < 0)
+		pps_err("unable to create sysfs entry for source %d", i);
+
+	return i;
+}
+EXPORT_SYMBOL(pps_register_source);
+
+static void __pps_unregister_source(struct pps_source_info_s *info)
+{  
+	int i;
+
+	for (i = 0; i < PPS_MAX_SOURCES; i++)
+		if (pps_is_allocated(i) && pps_source[i].info == info)
+			break;
+
+	if (i >= PPS_MAX_SOURCES) {
+		pps_err("warning! Try to unregister an unknow PPS source");
+		return;
+	}
+
+	/* Deallocate the PPS source */
+	pps_source[i].info = &dummy_info; 
+} 
+
+void pps_unregister_source(struct pps_source_info_s *info)
+{
+
+	pps_sysfs_remove_source_entry(info);
+
+	if (mutex_lock_interruptible(&pps_mutex))
+		return;
+	__pps_unregister_source(info);
+	mutex_unlock(&pps_mutex);
+}
+EXPORT_SYMBOL(pps_unregister_source);
+
+void pps_event(int source, int event, void *data)
+{
+	struct timespec ts;
+
+	/* First of all we get the time stamp... */
+	getnstimeofday(&ts);
+
+	if ((event & (PPS_CAPTUREASSERT|PPS_CAPTURECLEAR)) == 0 ) {
+		pps_err("unknow event (%x) for source %d", event, source);
+		return;
+	}
+
+	/* Must call the echo function? */
+	if ((pps_source[source].params.mode & (PPS_ECHOASSERT|PPS_ECHOCLEAR)) != 0)
+		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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].assert_tu.tspec = ts;
+		pps_source[source].assert_sequence++;
+		pps_dbg("capture assert seq #%lu for source %d", 
+			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.tspec);
+
+		/* Save the time stamp */
+		pps_source[source].clear_tu.tspec = ts;
+		pps_source[source].clear_sequence++;
+		pps_dbg("capture clear seq #%lu for source %d", 
+			pps_source[source].clear_sequence, source);
+	}
+
+	pps_source[source].go = ~0;
+	wake_up_interruptible(&pps_source[source].queue);
+}
+EXPORT_SYMBOL(pps_event);
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
new file mode 100644
index 0000000..5907c94
--- /dev/null
+++ b/drivers/pps/pps.c
@@ -0,0 +1,451 @@
+/*
+ * 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/compat.h>
+#include <linux/pps.h>
+#include <asm/uaccess.h>
+
+/*
+ * Global variables
+ */
+
+struct pps_s pps_source[PPS_MAX_SOURCES];
+DEFINE_MUTEX(pps_mutex);
+
+void dummy_echo(int source, int event, void *data) { }
+struct pps_source_info_s dummy_info;	/* Dummy PPS info for unallocated
+					   PPS sources */
+
+/*
+ * 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;
+
+	pps_dbg("%s: cmd %d", __FUNCTION__, cmd);
+
+	/* Sanity checks */
+	if (_IOC_TYPE(cmd) != 'P')
+		return -EOPNOTSUPP;
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		ret = !access_ok(VERIFY_WRITE, arg, _IOC_SIZE(cmd));
+	else if (_IOC_DIR(cmd) & _IOC_WRITE)
+		ret = !access_ok(VERIFY_READ, arg, _IOC_SIZE(cmd));
+	if (ret)
+		return -EFAULT;
+
+	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;
+		}
+
+		pps_dbg("PPS_CMD_FIND_SRC: source %d", data.source);
+
+		data.source = pps_find_source(data.source);
+		if (data.source < 0) {
+			pps_dbg("no PPS devices found");
+			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;
+		}
+
+		pps_dbg("PPS_CMD_FIND_PATH: path %s", data.path);
+
+		data.source = pps_find_path(data.path);
+		if (data.source < 0) {
+			pps_dbg("no PPS devices found");
+			ret = -ENODEV;
+			goto sys_time_pps_cmd_exit;
+	 	}
+
+		break;
+
+	default :
+		pps_err("invalid sys_time_pps_cmd %d", 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_params __user *params)
+{
+	int ret = 0;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, params, sizeof(struct pps_params)))
+		return -EFAULT;
+
+	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_params));
+	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_params __user *params)
+{
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Check the capabilities */
+	if (!capable(CAP_SYS_TIME))
+		return -EPERM;
+
+	/* Sanity checks */
+	if (!params)
+		return -EINVAL;
+	if (!access_ok(VERIFY_READ, params, sizeof(struct pps_params)))
+		return -EFAULT;
+	if ((params->mode & ~pps_source[source].info->mode) != 0) {
+		pps_dbg("unsupported capabilities");
+		return -EINVAL;
+ 	}
+	if ((params->mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
+		pps_dbg("capture mode unspecified");
+		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_params));
+	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 */
+		pps_dbg("time format unspecified");
+		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;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (!mode)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, mode, sizeof(int)))
+		return -EFAULT;
+
+	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;
+}
+
+static long __sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec *timeout)
+{
+	unsigned long ticks;
+	struct pps_info pi;
+	int ret;
+
+	pps_dbg("%s: source %d", __FUNCTION__, source);
+
+	/* Sanity checks */
+	if (tsformat != PPS_TSFMT_TSPEC) {
+		pps_dbg("unsupported time format");
+		return -EINVAL;
+ 	}
+	if (!info)
+		return -EINVAL;
+	if (!access_ok(VERIFY_WRITE, info, sizeof(struct pps_info)))
+		return -EFAULT;
+
+	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->tv_sec != -1) {
+		pps_dbg("timeout %ld.%09ld", timeout->tv_sec, timeout->tv_nsec);
+		ticks = timeout->tv_sec * HZ;
+		ticks += timeout->tv_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) {
+				pps_dbg("timeout expired");
+				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) {
+		pps_dbg("pending signal caught");
+		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_info));
+	if (ret)
+		ret = -EFAULT;
+
+sys_time_pps_fetch_exit:
+	mutex_unlock(&pps_mutex);
+
+	return ret;
+}
+
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info, 
+					const struct timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+		if (ret)
+			return ret;
+	}
+	else
+		to.tv_sec = -1;	
+
+	return __sys_time_pps_fetch(source, tsformat, info, timeout);
+}
+
+#ifdef CONFIG_COMPAT
+asmlinkage long compat_sys_time_pps_fetch(int source, const int tsformat,
+				struct pps_info __user *info, 
+				const struct compat_timespec __user *timeout)
+{
+	int ret;
+	struct timespec to;
+
+	if (timeout) {
+		ret = get_compat_timespec(&to, timeout);
+		if (ret)
+			return -EFAULT;
+	}
+	else
+		to.tv_sec = -1;	
+	
+	return __sys_time_pps_fetch(source, tsformat, info, &to);
+}
+#endif
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_exit(void)
+{
+	pps_sysfs_unregister();
+
+	pps_info("LinuxPPS API ver. %d removed", PPS_API_VERS);
+}
+
+static int __init pps_init(void)
+{
+	int i, ret;
+
+	/* Init pps_source info */
+	dummy_info.echo = dummy_echo;
+	for (i = 0; i < PPS_MAX_SOURCES; i++) {
+		pps_source[i].info = &dummy_info;
+		init_waitqueue_head(&pps_source[i].queue);
+	}
+
+	/* Register to sysfs */
+	ret = pps_sysfs_register();
+	if (ret < 0) {
+		pps_err("unable to register sysfs");
+		return ret;
+	}
+
+	pps_info("LinuxPPS API ver. %d registered", PPS_API_VERS);
+	pps_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
+		"<giometti@linux.it>", 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..0dae24b
--- /dev/null
+++ b/drivers/pps/sysfs.c
@@ -0,0 +1,219 @@
+/*
+ * 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, "%ld.%09ld#%ld\n",
+			dev->assert_tu.tspec.tv_sec,
+			dev->assert_tu.tspec.tv_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, "%ld.%09ld#%ld\n",
+			dev->clear_tu.tspec.tv_sec,
+			dev->clear_tu.tspec.tv_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..4a9906f 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 +634,52 @@ 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) {
+		pps_err("cannot register PPS source \"%s\"", state->pps_info.path);
+		return ret;
+	}
+	port->pps_source = ret;
+	pps_info("PPS source #%d \"%s\" added to the system ",
+		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);
+	pps_dbg("PPS source #%d \"%s\" removed from the system",
+	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 +854,19 @@ 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 +2155,12 @@ 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 +2410,12 @@ 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..f53d9f4 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);
+	pps_dbg("parport_pc: PPS assert event at %lu on source #%d",
+		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..6b53864
--- /dev/null
+++ b/include/linux/pps.h
@@ -0,0 +1,211 @@
+/*
+ * 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 <asm/types.h>
+#include <sys/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
+
+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 */
+};
+
+/*
+ * 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-rc2"
+
+#ifdef CONFIG_PPS_DEBUG
+#define pps_dbg(format, arg...) printk(KERN_DEBUG "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#else
+#define pps_dbg(format, arg...) do {} while (0)
+#endif
+
+#define pps_err(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+#define pps_info(format, arg...) printk(KERN_INFO "%s: " format "\n" , \
+	KBUILD_MODNAME , ## arg)
+
+/*
+ * 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);/* the 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_params params;		/* PPS's current params */
+
+	volatile unsigned long assert_sequence;	/* PPS' assert event seq # */
+	volatile unsigned long clear_sequence;	/* PPS' clear event seq # */
+	volatile union pps_timeu assert_tu;
+	volatile union pps_timeu 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;
+extern struct pps_source_info_s dummy_info;
+
+/*
+ * Global functions
+ */
+
+static inline int pps_is_allocated(int source)
+{
+	return pps_source[source].info != &dummy_info;
+}
+
+#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..ba4503e 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 +481,27 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status)
 {
 	struct uart_info *info = port->info;
 
-	port->icount.dcd++;
+#ifdef CONFIG_PPS_CLIENT_UART
+	struct tty_driver *drv = port->info->tty->driver;
 
-#ifdef CONFIG_HARD_PPS
-	if ((port->flags & UPF_HARDPPS_CD) && status)
-		hardpps();
+	if (port->flags & UPF_HARDPPS_CD) {
+		if (status) {
+			pps_event(port->pps_source, PPS_CAPTUREASSERT, port);
+			pps_dbg("%s%d: PPS assert event at %lu on source #%d",
+				drv->driver_name, port->line,
+				jiffies, port->pps_source);
+		}
+		else {
+			pps_event(port->pps_source, PPS_CAPTURECLEAR, port);
+			pps_dbg("%s%d: PPS clear event at %lu on source #%d",
+				drv->driver_name, port->line,
+				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..853a21e 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 +612,16 @@ 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_params __user *params);
+asmlinkage long sys_time_pps_setparams(int source,
+					const struct pps_params __user *params);
+asmlinkage long sys_time_pps_getcap(int source, int __user *mode);
+asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
+					struct pps_info __user *info,
+					const struct timespec __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);

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 17:08 +0200, Rodolfo Giometti wrote:
> On Fri, Jun 29, 2007 at 12:38:02PM +0100, David Woodhouse wrote:
> > 
> > It doesn't apply to the current git tree, which has already had some new
> > system calls added.
> 
> Ok, here the patch against latest git commit.

  CC      fs/fcntl.o
In file included from include/linux/syscalls.h:69,
                 from fs/fcntl.c:8:
include/linux/pps.h:51: error: field ‘tspec’ has incomplete type
make[1]: *** [fs/fcntl.o] Error 1

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Fri, Jun 29, 2007 at 04:25:16PM +0100, David Woodhouse wrote:
> On Fri, 2007-06-29 at 17:08 +0200, Rodolfo Giometti wrote:
> > On Fri, Jun 29, 2007 at 12:38:02PM +0100, David Woodhouse wrote:
> > > 
> > > It doesn't apply to the current git tree, which has already had some new
> > > system calls added.
> > 
> > Ok, here the patch against latest git commit.
> 
>   CC      fs/fcntl.o
> In file included from include/linux/syscalls.h:69,
>                  from fs/fcntl.c:8:
> include/linux/pps.h:51: error: field ???tspec??? has incomplete type
> make[1]: *** [fs/fcntl.o] Error 1

Gulp! =:-o

On my system I get:

   giometti@zaigor:~/Projects/linuxpps/kernel$ touch fs/fcntl.c 
   giometti@zaigor:~/Projects/linuxpps/kernel$ make
     CHK     include/linux/version.h
     CHK     include/linux/utsrelease.h
     CALL    scripts/checksyscalls.sh
     CHK     include/linux/compile.h
     CC      fs/fcntl.o
     LD      fs/built-in.o
     GEN     .version
     CHK     include/linux/compile.h
     UPD     include/linux/compile.h
     CC      init/version.o
     LD      init/built-in.o
     LD      .tmp_vmlinux1
     KSYM    .tmp_kallsyms1.S
     AS      .tmp_kallsyms1.o
     LD      .tmp_vmlinux2
     KSYM    .tmp_kallsyms2.S
     AS      .tmp_kallsyms2.o
     LD      vmlinux
     SYSMAP  System.map
     SYSMAP  .tmp_System.map
     MODPOST vmlinux
   WARNING: arch/i386/kernel/built-in.o(.exit.text+0x18): Section mismatch: reference to .init.text: (after 'cache_remove_dev')
   WARNING: kernel/built-in.o(.text+0x13826): Section mismatch: reference to .init.text: (between 'kthreadd' and 'init_waitqueue_head')
     AS      arch/i386/boot/setup.o
     LD      arch/i386/boot/setup
     OBJCOPY arch/i386/boot/compressed/vmlinux.bin
     GZIP    arch/i386/boot/compressed/vmlinux.bin.gz
     LD      arch/i386/boot/compressed/piggy.o
     LD      arch/i386/boot/compressed/vmlinux
     OBJCOPY arch/i386/boot/vmlinux.bin
     BUILD   arch/i386/boot/bzImage
   Root device is (9, 0)
   Boot sector 512 bytes.
   Setup is 7057 bytes.
   System is 1348 kB
   Kernel: arch/i386/boot/bzImage is ready  (#135)
     Building modules, stage 2.
     MODPOST 69 modules

How is that possible??? I just git pull the linux code... maybe you
have a bit older version?

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 17:38 +0200, Rodolfo Giometti wrote:
> How is that possible??? I just git pull the linux code... maybe you
> have a bit older version?

<asm-i386/signal.h> includes <linux/time.h>, for some reason.
<asm-powerpc/signal.h> doesn't.

You shouldn't rely on <linux/time.h> being pulled in like that -- you
either need a forward declaration of struct timespec, or to include
<linux/time.h> for yourself from <linux/pps.h>

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 17:08 +0200, Rodolfo Giometti wrote:
> 
> +asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
> +                                       struct pps_info __user *info, 
> +                                       const struct timespec __user *timeout)
> +{
> +       int ret;
> +       struct timespec to;
> +
> +       if (timeout) {
> +               ret = copy_from_user(&to, timeout, sizeof(struct timespec));
> +               if (ret)
> +                       return ret; 

You missed one. This should be -EFAULT too. And there's not a huge
amount of point in keeping the access_ok() checks elsewhere, since
copy_to_user() does that for itself.

Oh, and I think you do need compat magic for 'struct pps_info' and
'struct pps_params' too -- there's a struct timespec hidden deep in
there, as well as 'unsigned long longpad[3]'.

Can you explain the 'union pps_timeu'? It seems very odd. How do we know
which member of the union should be used?

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 18:23 +0200, Rodolfo Giometti wrote:
> On Fri, Jun 29, 2007 at 04:41:33PM +0100, David Woodhouse wrote:
> > 
> > <asm-i386/signal.h> includes <linux/time.h>, for some reason.
> > <asm-powerpc/signal.h> doesn't.
> > 
> > You shouldn't rely on <linux/time.h> being pulled in like that -- you
> > either need a forward declaration of struct timespec, or to include
> > <linux/time.h> for yourself from <linux/pps.h>
> 
> Can you please check if this patch resolve your problem?
> 
> diff --git a/include/linux/pps.h b/include/linux/pps.h
> index 6b53864..fe8c645 100644
> --- a/include/linux/pps.h
> +++ b/include/linux/pps.h
> @@ -33,6 +33,7 @@
>  
>  #ifndef __KERNEL__
>  #include <asm/types.h>
> +#include <linux/time.h>
>  #include <sys/time.h>
>  #endif

You'll need to put it in an #else case, not in #ifndef __KERNEL__.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Fri, Jun 29, 2007 at 04:41:33PM +0100, David Woodhouse wrote:
> 
> <asm-i386/signal.h> includes <linux/time.h>, for some reason.
> <asm-powerpc/signal.h> doesn't.
> 
> You shouldn't rely on <linux/time.h> being pulled in like that -- you
> either need a forward declaration of struct timespec, or to include
> <linux/time.h> for yourself from <linux/pps.h>

Can you please check if this patch resolve your problem?

diff --git a/include/linux/pps.h b/include/linux/pps.h
index 6b53864..fe8c645 100644
--- a/include/linux/pps.h
+++ b/include/linux/pps.h
@@ -33,6 +33,7 @@
 
 #ifndef __KERNEL__
 #include <asm/types.h>
+#include <linux/time.h>
 #include <sys/time.h>
 #endif

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Fri, Jun 29, 2007 at 04:55:47PM +0100, David Woodhouse wrote:

> You missed one. This should be -EFAULT too. And there's not a huge
> amount of point in keeping the access_ok() checks elsewhere, since
> copy_to_user() does that for itself.

Ok, fixed.

> Oh, and I think you do need compat magic for 'struct pps_info' and
> 'struct pps_params' too -- there's a struct timespec hidden deep in
> there, as well as 'unsigned long longpad[3]'.

Gulp! Can you please give me some advices in order to solve also this
problem? Should I use some "ifdef CONFIG_COMPAT" into those
structures? :-o

> Can you explain the 'union pps_timeu'? It seems very odd. How do we know
> which member of the union should be used?

This union is defined by the RFC 2783... we can know which member of
the union should be used by using define PPS_TSFMT_TSPEC for variable
tsformat into function time_pps_fetch().

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Fri, Jun 29, 2007 at 05:23:28PM +0100, David Woodhouse wrote:
> 
> You'll need to put it in an #else case, not in #ifndef __KERNEL__.

Sorry. :)

diff --git a/include/linux/pps.h b/include/linux/pps.h
index 6b53864..9e3af51 100644
--- a/include/linux/pps.h
+++ b/include/linux/pps.h
@@ -34,6 +34,8 @@
 #ifndef __KERNEL__
 #include <asm/types.h>
 #include <sys/time.h>
+#else
+#include <linux/time.h>
 #endif
 
 #define PPS_API_VERS_2          2       /* LinuxPPS proposal, dated 2006-05 */

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 18:36 +0200, Rodolfo Giometti wrote:
> On Fri, Jun 29, 2007 at 05:23:28PM +0100, David Woodhouse wrote:
> > 
> > You'll need to put it in an #else case, not in #ifndef __KERNEL__.
> 
> Sorry. :)

That matches what I built with earlier.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Fri, 2007-06-29 at 18:34 +0200, Rodolfo Giometti wrote:
> Gulp! Can you please give me some advices in order to solve also this
> problem? Should I use some "ifdef CONFIG_COMPAT" into those
> structures? :-o 

Remember you have to support _both_ 32-bit and 64-bit system calls. You
need to define struct compat_pps_info and struct compat_pps_params, and 
you'll have to provide a compat wrapper for sys_time_pps_getparams() and
sys_time_pps_setparams(). You'll also need to extend your
compat_sys_time_pps_fetch() wrapper to handle the struct pps_info too.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Christoph Hellwig]

On Thu, Jun 28, 2007 at 06:14:50PM +0200, Rodolfo Giometti wrote:
> Hello,
> 
> here my new LinuxPPS patch.
> 
> What to do now for kernel inclusion? Should I provide several patches?
> If so how should I divide them?
> 
> Thanks a lot,

Sorry for coming in that late, but using syscalls for something as
periphal sounds like a very bad idea to me, and the syscalls aren't
defined nicely either (e.g. you have an ioctl lookalike).  I'd say
back to the drawingboard.

And yes, even ioctls are nicer than badly designed syscalls :)

Also code seems to be odd at least in a few places, e.g. all the access_oks
and double checks of the ioctl-lookalike commands should go.

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Sat, Jun 30, 2007 at 09:38:27AM +0100, Christoph Hellwig wrote:
> 
> Sorry for coming in that late, but using syscalls for something as
> periphal sounds like a very bad idea to me, and the syscalls aren't
> defined nicely either (e.g. you have an ioctl lookalike).  I'd say
> back to the drawingboard.

PPS API is not only a periphal class. RFC 2783 defines new «functions»
that allow accesso to internal system data collected by some
periferals but these devices are never managed as a tipical char or
block device.

I think implementing parts or full RFC 2783 PPS's functions as
syscalls are not so wrong... IMHO, at least! :)

> And yes, even ioctls are nicer than badly designed syscalls :)

I see, but consider that some PPS devices cannot be always connected
with a filedescriptor since, for example, some PPS devices are
connected by serial lines, other by parallel ports and other
(expecially on embedded systems) are connected by CPU's GPIOs.

An userland programs shouldn't know whenever these devices are
connected, they should only know how to collect PPS data from the
system.

> Also code seems to be odd at least in a few places, e.g. all the access_oks
> and double checks of the ioctl-lookalike commands should go.

I already removed such functions in my latest patches. :)

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Fri, Jun 29, 2007 at 05:40:52PM +0100, David Woodhouse wrote:
> 
> Remember you have to support _both_ 32-bit and 64-bit system calls. You
> need to define struct compat_pps_info and struct compat_pps_params, and 
> you'll have to provide a compat wrapper for sys_time_pps_getparams() and
> sys_time_pps_setparams(). You'll also need to extend your
> compat_sys_time_pps_fetch() wrapper to handle the struct pps_info too.

At this point I'm seriously considfering your previous suggestion:

   Had you considered changing the API so that you don't need the
   compatibility wrapper at all? Could you take an integer number of
   µS or ms instead of a struct timespec?

Maybe I can define a special struct for exchanging time data as:

   struct pps_timedata_s {
      long sec;
      long nsec;
   }

and managing time data conversions at userland...

What do you think about that? :)

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Stephen Rothwell]

[-- Attachment #1: Type: text/plain, Size: 656 bytes --]

On Sat, 30 Jun 2007 19:13:40 +0200 Rodolfo Giometti <giometti@enneenne.com> wrote:
>
> Maybe I can define a special struct for exchanging time data as:
> 
>    struct pps_timedata_s {
>       long sec;
>       long nsec;
>    }
> 
> and managing time data conversions at userland...
> 
> What do you think about that? :)

"long" is one of the datatypes that changes size between 32 bit and 64
bit, so not such a good choice. You could use __u32 or __64 (or
whatever), that makes it very clear that these are fixed size data types.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Sat, 2007-06-30 at 19:13 +0200, Rodolfo Giometti wrote:
> Maybe I can define a special struct for exchanging time data as:
> 
>    struct pps_timedata_s {
>       long sec;
>       long nsec;
>    } 

Seems reasonable enough in principle -- but whatever you do, don't use
"long" for it. That would definitely need different behaviour for 32-bit
vs. 64-bit. Use explicitly sized types such as uint32_t or uint64_t.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Sun, Jul 01, 2007 at 05:13:25PM +1000, Stephen Rothwell wrote:
> On Sat, 30 Jun 2007 19:13:40 +0200 Rodolfo Giometti <giometti@enneenne.com> wrote:
> >
> > Maybe I can define a special struct for exchanging time data as:
> > 
> >    struct pps_timedata_s {
> >       long sec;
> >       long nsec;
> >    }
> > 
> > and managing time data conversions at userland...
> > 
> > What do you think about that? :)
> 
> "long" is one of the datatypes that changes size between 32 bit and 64
> bit, so not such a good choice. You could use __u32 or __64 (or
> whatever), that makes it very clear that these are fixed size data types.

    struct pps_timedata_s {
       __32 sec;
       __32 nsec;
    }

Ok? I think 32 bits are enought for keeping seconds... :)

If you have no more advices I think I can start changing this part in
order to avoid using struct timespec.

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Sun, Jul 01, 2007 at 01:03:11PM +0100, David Woodhouse wrote:
> 
> Seems reasonable enough in principle -- but whatever you do, don't use
> "long" for it. That would definitely need different behaviour for 32-bit
> vs. 64-bit. Use explicitly sized types such as uint32_t or uint64_t.

Which is the difference in using __u32 or uint32_t? Maybe is better
defining the new struct as follow?

    struct pps_timedata_s {
       uint32_t sec;
       uint32_t nsec;
    }

or as:

    struct pps_timedata_s {
	__u32 sec;
	__u32 nsec;
    }

?

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

[-- Attachment #1: Type: text/plain, Size: 711 bytes --]

On Sun, Jul 01, 2007 at 01:03:11PM +0100, David Woodhouse wrote:
> 
> Seems reasonable enough in principle -- but whatever you do, don't use
> "long" for it. That would definitely need different behaviour for 32-bit
> vs. 64-bit. Use explicitly sized types such as uint32_t or uint64_t.

Here the patch to convert LinuxPPS data structs into fixed ones.

Please, take a look at it and report possible modifications.

Thanks for your time,

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

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 14151 bytes --]

diff --git a/Documentation/pps/timepps.h b/Documentation/pps/timepps.h
index d690aa6..fe8f467 100644
--- a/Documentation/pps/timepps.h
+++ b/Documentation/pps/timepps.h
@@ -28,6 +28,32 @@
 
 /* --- 3.2 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 */
@@ -86,7 +112,6 @@ void time_pps_readlink(char *link, int linklen, char *path, int pathlen)
 
 	/* Return the file name where "link" points to */
 	path[i] = '\0';
-	return;
 }
 
 #define PPS_HAVE_FINDPATH	1
@@ -108,8 +133,10 @@ int time_pps_findpath(char *path, int pathlen, char *idstring, int idlen)
 
 int time_pps_create(int source, pps_handle_t *handle)
 {
-	if (!handle)
-		return -EINVAL;
+	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. */
@@ -128,12 +155,33 @@ int time_pps_destroy(pps_handle_t handle)
 int time_pps_getparams(pps_handle_t handle,
 				pps_params_t *ppsparams)
 {
-	return syscall(__NR_time_pps_getparams, handle, 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);
 }
 
@@ -147,15 +195,41 @@ int time_pps_fetch(pps_handle_t handle, const int tsformat,
 				pps_info_t *ppsinfobuf,
 				const struct timespec *timeout)
 {
-	return syscall(__NR_time_pps_fetch, handle,
-				tsformat, ppsinfobuf, 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 */
-	return -EOPNOTSUPP;
+	errno = -EOPNOTSUPP;
+	return -1;
 }
 
 #endif   /* _SYS_TIMEPPS_H_ */
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index dd24c31..b6ad93e 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -31,17 +31,17 @@
  * Local functions
  */
 
-static void pps_add_offset(struct timespec *ts, struct timespec *offset)
+static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
 {
-	ts->tv_nsec += offset->tv_nsec;
-	if (ts->tv_nsec >= NSEC_PER_SEC) {
-		ts->tv_nsec -= NSEC_PER_SEC;
-		ts->tv_sec++;
-	} else if (ts->tv_nsec < 0) {
-		ts->tv_nsec += NSEC_PER_SEC;
-		ts->tv_sec--;
+	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->tv_sec += offset->tv_sec;
+	ts->sec += offset->sec;
 }
 
 /*
@@ -87,7 +87,7 @@ static int __pps_register_source(struct pps_source_info_s *info,
 	/* Allocate the PPS source.
 	 *
 	 * Note that we should reset all fields BUT "info" one! */
-	memset(&(pps_source[i].params), 0, sizeof(struct pps_params));
+	memset(&(pps_source[i].params), 0, sizeof(struct pps_kparams));
 	pps_source[i].params.api_version = PPS_API_VERS;
 	pps_source[i].params.mode = default_params;
 	pps_source[i].assert_sequence = 0;
@@ -155,10 +155,15 @@ EXPORT_SYMBOL(pps_unregister_source);
 
 void pps_event(int source, int event, void *data)
 {
-	struct timespec ts;
+	struct timespec __ts;
+	struct pps_ktime ts;
 
 	/* First of all we get the time stamp... */
-	getnstimeofday(&ts);
+	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 ) {
 		pps_err("unknow event (%x) for source %d", event, source);
@@ -175,24 +180,24 @@ void pps_event(int source, int event, void *data)
 		/* 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.tspec);
+				&pps_source[source].params.assert_off_tu);
 
 		/* Save the time stamp */
-		pps_source[source].assert_tu.tspec = ts;
+		pps_source[source].assert_tu = ts;
 		pps_source[source].assert_sequence++;
-		pps_dbg("capture assert seq #%lu for source %d", 
+		pps_dbg("capture assert seq #%u for source %d", 
 			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.tspec);
+				&pps_source[source].params.clear_off_tu);
 
 		/* Save the time stamp */
-		pps_source[source].clear_tu.tspec = ts;
+		pps_source[source].clear_tu = ts;
 		pps_source[source].clear_sequence++;
-		pps_dbg("capture clear seq #%lu for source %d", 
+		pps_dbg("capture clear seq #%u for source %d", 
 			pps_source[source].clear_sequence, source);
 	}
 
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 428c3b7..6f56931 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -168,7 +168,7 @@ sys_time_pps_cmd_exit:
 }
 
 asmlinkage long sys_time_pps_getparams(int source,
-					struct pps_params __user *params)
+					struct pps_kparams __user *params)
 {
 	int ret = 0;
 
@@ -189,7 +189,7 @@ asmlinkage long sys_time_pps_getparams(int source,
 
 	/* Return current parameters */
 	ret = copy_to_user(params, &pps_source[source].params,
-						sizeof(struct pps_params));
+						sizeof(struct pps_kparams));
 	if (ret)
 		ret = -EFAULT;
 
@@ -200,7 +200,7 @@ sys_time_pps_getparams_exit:
 }
 
 asmlinkage long sys_time_pps_setparams(int source,
-					const struct pps_params __user *params)
+					const struct pps_kparams __user *params)
 {
 	int ret;
 
@@ -233,7 +233,7 @@ asmlinkage long sys_time_pps_setparams(int source,
 
 	/* Save the new parameters */
 	ret = copy_from_user(&pps_source[source].params, params,
-						sizeof(struct pps_params));
+						sizeof(struct pps_kparams));
 	if (ret) {
 		ret = -EFAULT;
 		goto sys_time_pps_setparams_exit;
@@ -282,22 +282,16 @@ sys_time_pps_getcap_exit:
 	return ret;
 }
 
-asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
-					struct pps_info __user *info, 
-					const struct timespec __user *timeout)
+asmlinkage long sys_time_pps_fetch(int source, struct pps_kinfo __user *info, 
+					const struct pps_ktime __user *timeout)
 {
 	unsigned long ticks;
-	struct pps_info pi;
-	struct timespec to;
+	struct pps_kinfo pi;
+	struct pps_ktime to;
 	int ret;
 
 	pps_dbg("%s: source %d", __FUNCTION__, source);
 
-	/* Sanity checks */
-	if (tsformat != PPS_TSFMT_TSPEC) {
-		pps_dbg("unsupported time format");
-		return -EINVAL;
- 	}
 	if (!info)
 		return -EINVAL;
 
@@ -314,15 +308,15 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
 
  	/* Manage the timeout */
 	if (timeout) {
-		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+		ret = copy_from_user(&to, timeout, sizeof(struct pps_ktime));
 		if (ret) {
 			goto sys_time_pps_fetch_exit;
 			ret = -EFAULT;
 		}
-		if (to.tv_sec != -1) {
-			pps_dbg("timeout %ld.%09ld", to.tv_sec, to.tv_nsec);
-			ticks = to.tv_sec * HZ;
-			ticks += to.tv_nsec / (NSEC_PER_SEC / HZ);
+		if (to.sec != -1) {
+			pps_dbg("timeout %d.%09d", to.sec, to.nsec);
+			ticks = to.sec * HZ;
+			ticks += to.nsec / (NSEC_PER_SEC / HZ);
 
 			if (ticks != 0) {
 				ret = wait_event_interruptible_timeout(
@@ -352,7 +346,7 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
 	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_info));
+	ret = copy_to_user(info, &pi, sizeof(struct pps_kinfo));
 	if (ret)
 		ret = -EFAULT;
 
diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c
index 0dae24b..46d7b7f 100644
--- a/drivers/pps/sysfs.c
+++ b/drivers/pps/sysfs.c
@@ -34,9 +34,8 @@ static ssize_t pps_show_assert(struct class_device *cdev, char *buf)
 {
 	struct pps_s *dev = class_get_devdata(cdev);
 
-	return sprintf(buf, "%ld.%09ld#%ld\n",
-			dev->assert_tu.tspec.tv_sec,
-			dev->assert_tu.tspec.tv_nsec,
+	return sprintf(buf, "%d.%09d#%d\n",
+			dev->assert_tu.sec, dev->assert_tu.nsec,
 			dev->assert_sequence);
 }
 
@@ -44,9 +43,8 @@ static ssize_t pps_show_clear(struct class_device *cdev, char *buf)
 {
 	struct pps_s *dev = class_get_devdata(cdev);
 
-	return sprintf(buf, "%ld.%09ld#%ld\n",
-			dev->clear_tu.tspec.tv_sec,
-			dev->clear_tu.tspec.tv_nsec,
+	return sprintf(buf, "%d.%09d#%d\n",
+			dev->clear_tu.sec, dev->clear_tu.nsec,
 			dev->clear_sequence);
 }
 
diff --git a/include/linux/pps.h b/include/linux/pps.h
index 9e3af51..001b8bf 100644
--- a/include/linux/pps.h
+++ b/include/linux/pps.h
@@ -44,30 +44,24 @@
 
 #define PPS_MAX_NAME_LEN	32
 
-struct ntp_fp {
-	unsigned int integral;
-	unsigned int fractional;
+struct pps_ktime {
+	__u32 sec;
+	__u32 nsec;
 };
 
-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 */
+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_params {
+struct pps_kparams {
 	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 */
+	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
+	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
 };
 
 /*
@@ -162,12 +156,12 @@ struct pps_source_info_s {
 struct pps_s {
 	struct pps_source_info_s *info;		/* PSS source info */
 
-	struct pps_params params;		/* PPS's current params */
+	struct pps_kparams params;		/* PPS's current params */
 
-	volatile unsigned long assert_sequence;	/* PPS' assert event seq # */
-	volatile unsigned long clear_sequence;	/* PPS' clear event seq # */
-	volatile union pps_timeu assert_tu;
-	volatile union pps_timeu clear_tu;
+	volatile uint32_t assert_sequence;	/* PPS' assert event seq # */
+	volatile uint32_t clear_sequence;	/* PPS' clear event seq # */
+	volatile struct pps_ktime assert_tu;
+	volatile struct pps_ktime clear_tu;
 	int current_mode;			/* PPS mode at event time */
 
 	int go;					/* PPS event is arrived? */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 853a21e..bfc8899 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -614,13 +614,12 @@ 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_params __user *params);
+				       struct pps_kparams __user *params);
 asmlinkage long sys_time_pps_setparams(int source,
-					const struct pps_params __user *params);
+				       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, const int tsformat,
-					struct pps_info __user *info,
-					const struct timespec __user *timeout);
+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[]);
 

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Tue, 2007-07-03 at 11:48 +0200, Rodolfo Giometti wrote:
> On Sun, Jul 01, 2007 at 01:03:11PM +0100, David Woodhouse wrote:
> > 
> > Seems reasonable enough in principle -- but whatever you do, don't use
> > "long" for it. That would definitely need different behaviour for 32-bit
> > vs. 64-bit. Use explicitly sized types such as uint32_t or uint64_t.
> 
> Here the patch to convert LinuxPPS data structs into fixed ones.
> 
> Please, take a look at it and report possible modifications.

Looks relatively sane at first glance; busy this week so haven't looked
very hard yet. Two thing though... you're mixing proper C types
(uint32_t) and the Linux-specific legacy crap types (__u32). Pick one. I
won't recommend _which_ one, because if I do I'll make Andrew unhappy.
But pick one; don't use both at the same time.

Also read Documentation/volatile-considered-harmful.txt and ponder
deeply your use of 'volatile' on certain members of struct pps_s.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Tue, Jul 03, 2007 at 09:09:50AM -0400, David Woodhouse wrote:
> On Tue, 2007-07-03 at 11:48 +0200, Rodolfo Giometti wrote:
> > On Sun, Jul 01, 2007 at 01:03:11PM +0100, David Woodhouse wrote:
> > > 
> > > Seems reasonable enough in principle -- but whatever you do, don't use
> > > "long" for it. That would definitely need different behaviour for 32-bit
> > > vs. 64-bit. Use explicitly sized types such as uint32_t or uint64_t.
> > 
> > Here the patch to convert LinuxPPS data structs into fixed ones.
> > 
> > Please, take a look at it and report possible modifications.
> 
> Looks relatively sane at first glance; busy this week so haven't looked
> very hard yet. Two thing though... you're mixing proper C types
> (uint32_t) and the Linux-specific legacy crap types (__u32). Pick one. I
> won't recommend _which_ one, because if I do I'll make Andrew unhappy.
> But pick one; don't use both at the same time.
> 
> Also read Documentation/volatile-considered-harmful.txt and ponder
> deeply your use of 'volatile' on certain members of struct pps_s.

I will! Thanks a lot.

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Oleg Verych]

* Rodolfo Giometti (Thu, 28 Jun 2007 18:14:50 +0200)
* Organization: GNU/Linux Device Drivers, Embedded Systems and Courses

> +.PHONY : all depend dep
> +
> +all : .depend $(TARGETS)
> +
> +.depend depend dep :
> +	$(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
[]
> +# -- Clean section ------------------------------------------------------------
> +
> +.PHONY : clean
> +
> +clean :
> +	rm -f *.o *~ core .depend

Please see how currently .PHONY targets are used correctly, e.g. in
linux/Makefile.
____

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Sun, Jul 08, 2007 at 11:05:32AM +0200, Oleg Verych wrote:
> * Rodolfo Giometti (Thu, 28 Jun 2007 18:14:50 +0200)
> * Organization: GNU/Linux Device Drivers, Embedded Systems and Courses
> 
> > +.PHONY : all depend dep
> > +
> > +all : .depend $(TARGETS)
> > +
> > +.depend depend dep :
> > +	$(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
> []
> > +# -- Clean section ------------------------------------------------------------
> > +
> > +.PHONY : clean
> > +
> > +clean :
> > +	rm -f *.o *~ core .depend
> 
> Please see how currently .PHONY targets are used correctly, e.g. in
> linux/Makefile.

I don't understand why you wish I use linux PHONY targets management
in a documentation Makefile... I suppose you are talking about
linux/Documentation/pps/Makefile which is just an example about people
may compile some testing/debugging programs. :-o

Ciao,

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

Makefiles for GNU make (Re: [PATCH] LinuxPPS (with new syscalls API) - new version)

[Oleg Verych]

On Mon, Jul 09, 2007 at 11:16:43AM +0200, Rodolfo Giometti wrote:
> On Sun, Jul 08, 2007 at 11:05:32AM +0200, Oleg Verych wrote:
> > * Rodolfo Giometti (Thu, 28 Jun 2007 18:14:50 +0200)
> > * Organization: GNU/Linux Device Drivers, Embedded Systems and Courses
> > 
> > > +.PHONY : all depend dep
> > > +
> > > +all : .depend $(TARGETS)
> > > +
> > > +.depend depend dep :
> > > +	$(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
> > []
> > > +# -- Clean section ------------------------------------------------------------
> > > +
> > > +.PHONY : clean
> > > +
> > > +clean :
> > > +	rm -f *.o *~ core .depend
> > 
> > Please see how currently .PHONY targets are used correctly, e.g. in
> > linux/Makefile.
> 
> I don't understand why you wish I use linux PHONY targets management

Sorry i was not clear. Problem is `GNU make'[0], not management.

[0] <http://article.gmane.org/gmane.comp.gnu.make.bugs/2481>

> in a documentation Makefile... I suppose you are talking about
> linux/Documentation/pps/Makefile which is just an example about people
> may compile some testing/debugging programs. :-o

So, after this example you may write correct Makefiles for `GNU make'.

> Ciao,
> 
> Rodolfo
> 
____

Re: Makefiles for GNU make (Re: [PATCH] LinuxPPS (with new syscalls API) - new version)

[Rodolfo Giometti]

On Mon, Jul 09, 2007 at 12:56:11PM +0200, Oleg Verych wrote:
> On Mon, Jul 09, 2007 at 11:16:43AM +0200, Rodolfo Giometti wrote:
> > On Sun, Jul 08, 2007 at 11:05:32AM +0200, Oleg Verych wrote:
> > > * Rodolfo Giometti (Thu, 28 Jun 2007 18:14:50 +0200)
> > > * Organization: GNU/Linux Device Drivers, Embedded Systems and Courses
> > > 
> > > > +.PHONY : all depend dep
> > > > +
> > > > +all : .depend $(TARGETS)
> > > > +
> > > > +.depend depend dep :
> > > > +	$(CC) $(CFLAGS) -M $(TARGETS:=.c) > .depend
> > > []
> > > > +# -- Clean section ------------------------------------------------------------
> > > > +
> > > > +.PHONY : clean
> > > > +
> > > > +clean :
> > > > +	rm -f *.o *~ core .depend
> > > 
> > > Please see how currently .PHONY targets are used correctly, e.g. in
> > > linux/Makefile.
> > 
> > I don't understand why you wish I use linux PHONY targets management
> 
> Sorry i was not clear. Problem is `GNU make'[0], not management.
> 
> [0] <http://article.gmane.org/gmane.comp.gnu.make.bugs/2481>
> 
> > in a documentation Makefile... I suppose you are talking about
> > linux/Documentation/pps/Makefile which is just an example about people
> > may compile some testing/debugging programs. :-o
> 
> So, after this example you may write correct Makefiles for `GNU make'.

I see... but I'm still a bit confused... if I well understand I should
change the Makefile as follow:

   diff --git a/Documentation/pps/Makefile b/Documentation/pps/Makefile
   index a2660a2..d766447 100644
   --- a/Documentation/pps/Makefile
   +++ b/Documentation/pps/Makefile
   @@ -6,7 +6,7 @@ CFLAGS += -ggdb
    
    # -- Actions section ---------------------------------------------------------- 
   -.PHONY : all depend dep
   +.PHONY : depend dep
    
    all : .depend $(TARGETS)
    
   @@ -20,8 +20,6 @@ endif
    
    # -- Clean section ------------------------------------------------------------ 
   -.PHONY : clean
   -
    clean :
           rm -f *.o *~ core .depend
           rm -f ${TARGETS}

Is that right?

Thanks,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

[-- Attachment #1: Type: text/plain, Size: 1167 bytes --]

On Tue, Jul 03, 2007 at 09:09:50AM -0400, David Woodhouse wrote:
> 
> Looks relatively sane at first glance; busy this week so haven't looked
> very hard yet. Two thing though... you're mixing proper C types
> (uint32_t) and the Linux-specific legacy crap types (__u32). Pick one. I
> won't recommend _which_ one, because if I do I'll make Andrew unhappy.
> But pick one; don't use both at the same time.

Ok. I choose __u32. :)

> Also read Documentation/volatile-considered-harmful.txt and ponder
> deeply your use of 'volatile' on certain members of struct pps_s.

I read such document but I'm still convinced that the attribute
volatile is needed for {assert,clear}_sequence and {assert,clear}_tu
since inside pps_event() they are updated without any locks at all
thanks to the dummy_info variable which is used for unallocated PPS
sources.

Here you can find my last patch.

Thanks again,

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

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 13980 bytes --]

diff --git a/Documentation/pps/Makefile b/Documentation/pps/Makefile
diff --git a/Documentation/pps/timepps.h b/Documentation/pps/timepps.h
index a7719eb..0427ee0 100644
--- a/Documentation/pps/timepps.h
+++ b/Documentation/pps/timepps.h
@@ -28,6 +28,32 @@
 
 /* --- 3.2 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 */
@@ -129,13 +155,34 @@ int time_pps_destroy(pps_handle_t handle)
 int time_pps_getparams(pps_handle_t handle,
 				pps_params_t *ppsparams)
 {
-	return syscall(__NR_time_pps_getparams, handle, 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)
 {
-	return syscall(__NR_time_pps_getparams, handle, 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 */
@@ -148,8 +195,33 @@ int time_pps_fetch(pps_handle_t handle, const int tsformat,
 				pps_info_t *ppsinfobuf,
 				const struct timespec *timeout)
 {
-	return syscall(__NR_time_pps_fetch, handle,
-				tsformat, ppsinfobuf, 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,
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index dd24c31..b6ad93e 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -31,17 +31,17 @@
  * Local functions
  */
 
-static void pps_add_offset(struct timespec *ts, struct timespec *offset)
+static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
 {
-	ts->tv_nsec += offset->tv_nsec;
-	if (ts->tv_nsec >= NSEC_PER_SEC) {
-		ts->tv_nsec -= NSEC_PER_SEC;
-		ts->tv_sec++;
-	} else if (ts->tv_nsec < 0) {
-		ts->tv_nsec += NSEC_PER_SEC;
-		ts->tv_sec--;
+	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->tv_sec += offset->tv_sec;
+	ts->sec += offset->sec;
 }
 
 /*
@@ -87,7 +87,7 @@ static int __pps_register_source(struct pps_source_info_s *info,
 	/* Allocate the PPS source.
 	 *
 	 * Note that we should reset all fields BUT "info" one! */
-	memset(&(pps_source[i].params), 0, sizeof(struct pps_params));
+	memset(&(pps_source[i].params), 0, sizeof(struct pps_kparams));
 	pps_source[i].params.api_version = PPS_API_VERS;
 	pps_source[i].params.mode = default_params;
 	pps_source[i].assert_sequence = 0;
@@ -155,10 +155,15 @@ EXPORT_SYMBOL(pps_unregister_source);
 
 void pps_event(int source, int event, void *data)
 {
-	struct timespec ts;
+	struct timespec __ts;
+	struct pps_ktime ts;
 
 	/* First of all we get the time stamp... */
-	getnstimeofday(&ts);
+	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 ) {
 		pps_err("unknow event (%x) for source %d", event, source);
@@ -175,24 +180,24 @@ void pps_event(int source, int event, void *data)
 		/* 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.tspec);
+				&pps_source[source].params.assert_off_tu);
 
 		/* Save the time stamp */
-		pps_source[source].assert_tu.tspec = ts;
+		pps_source[source].assert_tu = ts;
 		pps_source[source].assert_sequence++;
-		pps_dbg("capture assert seq #%lu for source %d", 
+		pps_dbg("capture assert seq #%u for source %d", 
 			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.tspec);
+				&pps_source[source].params.clear_off_tu);
 
 		/* Save the time stamp */
-		pps_source[source].clear_tu.tspec = ts;
+		pps_source[source].clear_tu = ts;
 		pps_source[source].clear_sequence++;
-		pps_dbg("capture clear seq #%lu for source %d", 
+		pps_dbg("capture clear seq #%u for source %d", 
 			pps_source[source].clear_sequence, source);
 	}
 
diff --git a/drivers/pps/pps.c b/drivers/pps/pps.c
index 428c3b7..3545c58 100644
--- a/drivers/pps/pps.c
+++ b/drivers/pps/pps.c
@@ -168,7 +168,7 @@ sys_time_pps_cmd_exit:
 }
 
 asmlinkage long sys_time_pps_getparams(int source,
-					struct pps_params __user *params)
+					struct pps_kparams __user *params)
 {
 	int ret = 0;
 
@@ -189,7 +189,7 @@ asmlinkage long sys_time_pps_getparams(int source,
 
 	/* Return current parameters */
 	ret = copy_to_user(params, &pps_source[source].params,
-						sizeof(struct pps_params));
+						sizeof(struct pps_kparams));
 	if (ret)
 		ret = -EFAULT;
 
@@ -200,7 +200,7 @@ sys_time_pps_getparams_exit:
 }
 
 asmlinkage long sys_time_pps_setparams(int source,
-					const struct pps_params __user *params)
+					const struct pps_kparams __user *params)
 {
 	int ret;
 
@@ -233,7 +233,7 @@ asmlinkage long sys_time_pps_setparams(int source,
 
 	/* Save the new parameters */
 	ret = copy_from_user(&pps_source[source].params, params,
-						sizeof(struct pps_params));
+						sizeof(struct pps_kparams));
 	if (ret) {
 		ret = -EFAULT;
 		goto sys_time_pps_setparams_exit;
@@ -282,22 +282,16 @@ sys_time_pps_getcap_exit:
 	return ret;
 }
 
-asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
-					struct pps_info __user *info, 
-					const struct timespec __user *timeout)
+asmlinkage long sys_time_pps_fetch(int source, struct pps_kinfo __user *info, 
+					const struct pps_ktime __user *timeout)
 {
 	unsigned long ticks;
-	struct pps_info pi;
-	struct timespec to;
+	struct pps_kinfo pi;
+	struct pps_ktime to;
 	int ret;
 
 	pps_dbg("%s: source %d", __FUNCTION__, source);
 
-	/* Sanity checks */
-	if (tsformat != PPS_TSFMT_TSPEC) {
-		pps_dbg("unsupported time format");
-		return -EINVAL;
- 	}
 	if (!info)
 		return -EINVAL;
 
@@ -314,25 +308,23 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
 
  	/* Manage the timeout */
 	if (timeout) {
-		ret = copy_from_user(&to, timeout, sizeof(struct timespec));
+		ret = copy_from_user(&to, timeout, sizeof(struct pps_ktime));
 		if (ret) {
 			goto sys_time_pps_fetch_exit;
 			ret = -EFAULT;
 		}
-		if (to.tv_sec != -1) {
-			pps_dbg("timeout %ld.%09ld", to.tv_sec, to.tv_nsec);
-			ticks = to.tv_sec * HZ;
-			ticks += to.tv_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) {
-					pps_dbg("timeout expired");
-					ret = -ETIMEDOUT;
-					goto sys_time_pps_fetch_exit;
-				}
+		pps_dbg("timeout %d.%09d", 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) {
+				pps_dbg("timeout expired");
+				ret = -ETIMEDOUT;
+				goto sys_time_pps_fetch_exit;
 			}
 		}
  	} else
@@ -352,7 +344,7 @@ asmlinkage long sys_time_pps_fetch(int source, const int tsformat,
 	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_info));
+	ret = copy_to_user(info, &pi, sizeof(struct pps_kinfo));
 	if (ret)
 		ret = -EFAULT;
 
diff --git a/drivers/pps/sysfs.c b/drivers/pps/sysfs.c
index 0dae24b..46d7b7f 100644
--- a/drivers/pps/sysfs.c
+++ b/drivers/pps/sysfs.c
@@ -34,9 +34,8 @@ static ssize_t pps_show_assert(struct class_device *cdev, char *buf)
 {
 	struct pps_s *dev = class_get_devdata(cdev);
 
-	return sprintf(buf, "%ld.%09ld#%ld\n",
-			dev->assert_tu.tspec.tv_sec,
-			dev->assert_tu.tspec.tv_nsec,
+	return sprintf(buf, "%d.%09d#%d\n",
+			dev->assert_tu.sec, dev->assert_tu.nsec,
 			dev->assert_sequence);
 }
 
@@ -44,9 +43,8 @@ static ssize_t pps_show_clear(struct class_device *cdev, char *buf)
 {
 	struct pps_s *dev = class_get_devdata(cdev);
 
-	return sprintf(buf, "%ld.%09ld#%ld\n",
-			dev->clear_tu.tspec.tv_sec,
-			dev->clear_tu.tspec.tv_nsec,
+	return sprintf(buf, "%d.%09d#%d\n",
+			dev->clear_tu.sec, dev->clear_tu.nsec,
 			dev->clear_sequence);
 }
 
diff --git a/include/linux/pps.h b/include/linux/pps.h
index 9e3af51..05397cd 100644
--- a/include/linux/pps.h
+++ b/include/linux/pps.h
@@ -44,30 +44,24 @@
 
 #define PPS_MAX_NAME_LEN	32
 
-struct ntp_fp {
-	unsigned int integral;
-	unsigned int fractional;
+struct pps_ktime {
+	__u32 sec;
+	__u32 nsec;
 };
 
-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 */
+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_params {
+struct pps_kparams {
 	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 */
+	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
+	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
 };
 
 /*
@@ -162,12 +156,12 @@ struct pps_source_info_s {
 struct pps_s {
 	struct pps_source_info_s *info;		/* PSS source info */
 
-	struct pps_params params;		/* PPS's current params */
+	struct pps_kparams params;		/* PPS's current params */
 
-	volatile unsigned long assert_sequence;	/* PPS' assert event seq # */
-	volatile unsigned long clear_sequence;	/* PPS' clear event seq # */
-	volatile union pps_timeu assert_tu;
-	volatile union pps_timeu clear_tu;
+	volatile __u32 assert_sequence;		/* PPS' assert event seq # */
+	volatile __u32 clear_sequence;		/* PPS' clear event seq # */
+	volatile struct pps_ktime assert_tu;
+	volatile struct pps_ktime clear_tu;
 	int current_mode;			/* PPS mode at event time */
 
 	int go;					/* PPS event is arrived? */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 853a21e..bfc8899 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -614,13 +614,12 @@ 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_params __user *params);
+				       struct pps_kparams __user *params);
 asmlinkage long sys_time_pps_setparams(int source,
-					const struct pps_params __user *params);
+				       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, const int tsformat,
-					struct pps_info __user *info,
-					const struct timespec __user *timeout);
+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[]);
 

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Lennart Sorensen]

On Sun, Jul 01, 2007 at 09:24:41PM +0200, Rodolfo Giometti wrote:
>     struct pps_timedata_s {
>        __32 sec;
>        __32 nsec;
>     }
> 
> Ok? I think 32 bits are enought for keeping seconds... :)

You want to purposely define an API that will break in 23 years (or is
that 83 years since you made it unsigned potentially)?  Why not 64bit
for seconds and 32bit for nsec.  That should cover it for long enough.
When the unix time format was created 37 years ago, I could see thinking
32bit seemed reasonable, but why do it now.  We have ram enough for
64bits.

--
Len Sorensen

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Mon, 2007-07-09 at 15:19 +0200, Rodolfo Giometti wrote:
> 
> > Also read Documentation/volatile-considered-harmful.txt and ponder
> > deeply your use of 'volatile' on certain members of struct pps_s.
> 
> I read such document but I'm still convinced that the attribute
> volatile is needed for {assert,clear}_sequence and {assert,clear}_tu
> since inside pps_event() they are updated without any locks at all
> thanks to the dummy_info variable which is used for unallocated PPS
> sources.

I'm sure the version with 'volatile' will also be broken then. Sounds
like the right answer is to fix the locking.

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Tue, 2007-07-10 at 18:36 +0200, Rodolfo Giometti wrote:
> Sorry I wrote wrong. I meant __u32.

We guessed that much.

> I can use __u64 for seconds but doing this there could be problems for
> 32 bits platforms? =:-o

Why would there be problems?

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Tue, Jul 10, 2007 at 12:01:51PM -0400, Lennart Sorensen wrote:
> On Sun, Jul 01, 2007 at 09:24:41PM +0200, Rodolfo Giometti wrote:
> >     struct pps_timedata_s {
> >        __32 sec;
> >        __32 nsec;
> >     }
> > 
> > Ok? I think 32 bits are enought for keeping seconds... :)
> 
> You want to purposely define an API that will break in 23 years (or is
> that 83 years since you made it unsigned potentially)?  Why not 64bit
> for seconds and 32bit for nsec.  That should cover it for long enough.
> When the unix time format was created 37 years ago, I could see thinking
> 32bit seemed reasonable, but why do it now.  We have ram enough for
> 64bits.

Sorry I wrote wrong. I meant __u32.

I can use __u64 for seconds but doing this there could be problems for
32 bits platforms? =:-o

Rodolfo (not a 64 bits guru :)

-- 

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Tue, Jul 10, 2007 at 05:05:47PM +0100, David Woodhouse wrote:
> 
> I'm sure the version with 'volatile' will also be broken then. Sounds
> like the right answer is to fix the locking.

But wish avoiding locking at all since this may delay the time stamp
recording. We (the LinuxPPS guys) niticed that just a single
instruction my degrade the time setting about 50%!

I avoid locking just using a pointer and setting it to a dummy
structure when not used... is that wrong? :-o

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Tue, Jul 10, 2007 at 05:36:16PM +0100, David Woodhouse wrote:
> 
> Why would there be problems?

I'm just asking since I don't know well 64 bits architectures. :)

However, how can I fix 64 bits seconds into struct timespec?

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Lennart Sorensen]

On Tue, Jul 10, 2007 at 06:36:25PM +0200, Rodolfo Giometti wrote:
> Sorry I wrote wrong. I meant __u32.
> 
> I can use __u64 for seconds but doing this there could be problems for
> 32 bits platforms? =:-o

32bit platforms can still work with 64bit values, they may just not be
quite as efficient about it.

After all we support files with more than 2^32 bytes in them, so the
file access structures must have more than 32bit values in them.

--
Len Sorensen

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Roman Zippel]

Hi,

On Tuesday 10 July 2007, Lennart Sorensen wrote:

> On Sun, Jul 01, 2007 at 09:24:41PM +0200, Rodolfo Giometti wrote:
> >     struct pps_timedata_s {
> >        __32 sec;
> >        __32 nsec;
> >     }
> >
> > Ok? I think 32 bits are enought for keeping seconds... :)
>
> You want to purposely define an API that will break in 23 years (or is
> that 83 years since you made it unsigned potentially)?

This is really not an API that needs to deal with such large time range.

bye, Roman

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Tue, Jul 10, 2007 at 06:03:10PM -0400, Lennart Sorensen wrote:
> 
> 32bit platforms can still work with 64bit values, they may just not be
> quite as efficient about it.
> 
> After all we support files with more than 2^32 bytes in them, so the
> file access structures must have more than 32bit values in them.

My question is: how can I fit a 64 bits number of seconds into
timespec structure which, for 32 bits architetures, has a 32 bits bits
number of seconds?

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[David Woodhouse]

On Tue, 2007-07-10 at 18:38 +0200, Rodolfo Giometti wrote:
> On Tue, Jul 10, 2007 at 05:05:47PM +0100, David Woodhouse wrote:
> > 
> > I'm sure the version with 'volatile' will also be broken then. Sounds
> > like the right answer is to fix the locking.
> 
> But wish avoiding locking at all since this may delay the time stamp
> recording. We (the LinuxPPS guys) niticed that just a single
> instruction my degrade the time setting about 50%!
> 
> I avoid locking just using a pointer and setting it to a dummy
> structure when not used... is that wrong? :-o

Almost certainly (admittedly said without looking).

-- 
dwmw2

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Wed, Jul 11, 2007 at 10:17:47AM +0100, David Woodhouse wrote:
> On Tue, 2007-07-10 at 18:38 +0200, Rodolfo Giometti wrote:
> > On Tue, Jul 10, 2007 at 05:05:47PM +0100, David Woodhouse wrote:
> > > 
> > > I'm sure the version with 'volatile' will also be broken then. Sounds
> > > like the right answer is to fix the locking.
> > 
> > But wish avoiding locking at all since this may delay the time stamp
> > recording. We (the LinuxPPS guys) niticed that just a single
> > instruction my degrade the time setting about 50%!
> > 
> > I avoid locking just using a pointer and setting it to a dummy
> > structure when not used... is that wrong? :-o
> 
> Almost certainly (admittedly said without looking).

Please take a look at the code. I'm quite sure that it's ok. :)

I just set a pointer to a dummy struct or a valid one. By doing like
this I don't need a lock in the irq handler since it writes always
into a valid area. At non irq time I simply use a mutex lock.

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Lennart Sorensen]

On Wed, Jul 11, 2007 at 10:06:34AM +0200, Rodolfo Giometti wrote:
> My question is: how can I fit a 64 bits number of seconds into
> timespec structure which, for 32 bits architetures, has a 32 bits bits
> number of seconds?

I imagine you can't.  I have no idea if there are any intensions to
change the definition of timespec on 32bit architectures, or if the
thought is that they will all be dead before it becomes a problem. :)

I still think the API you define for PPS should support 64bit seconds,
even if on some systems you can't take advantage of it.

--
Len Sorensen

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Lennart Sorensen]

On Wed, Jul 11, 2007 at 03:18:46AM +0200, Roman Zippel wrote:
> This is really not an API that needs to deal with such large time range.

No one will want to use PPS API to keep accurate time past 2030?  Why
not?  Or should we be forced to invent a new PPS API before then to fix
this one?

Actually, come to think of it, is this passing a current time, or it it
passing an interval since last PPS?  If it is an interval, then yes
never mind, we don't need that many seconds (usually 1 or 2 at most).
For some reason I thought this was for passing the current time of a
stamp.

--
Len Sorensen

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Wed, Jul 11, 2007 at 11:22:38AM -0400, Lennart Sorensen wrote:
> On Wed, Jul 11, 2007 at 10:06:34AM +0200, Rodolfo Giometti wrote:
> > My question is: how can I fit a 64 bits number of seconds into
> > timespec structure which, for 32 bits architetures, has a 32 bits bits
> > number of seconds?
> 
> I imagine you can't.  I have no idea if there are any intensions to
> change the definition of timespec on 32bit architectures, or if the
> thought is that they will all be dead before it becomes a problem. :)
> 
> I still think the API you define for PPS should support 64bit seconds,
> even if on some systems you can't take advantage of it.

So on 32 bits systems I simply drop the high part of the second
data... is that right?

Ciao,

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Rodolfo Giometti]

On Wed, Jul 11, 2007 at 11:24:55AM -0400, Lennart Sorensen wrote:

> For some reason I thought this was for passing the current time of a
> stamp.

And you was right. :)

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

Re: [PATCH] LinuxPPS (with new syscalls API) - new version

[Roman Zippel]

Hi,

On Wed, 11 Jul 2007, Lennart Sorensen wrote:

> On Wed, Jul 11, 2007 at 03:18:46AM +0200, Roman Zippel wrote:
> > This is really not an API that needs to deal with such large time range.
> 
> No one will want to use PPS API to keep accurate time past 2030?  Why
> not?  Or should we be forced to invent a new PPS API before then to fix
> this one?

That's not necessary.

> Actually, come to think of it, is this passing a current time, or it it
> passing an interval since last PPS?  If it is an interval, then yes
> never mind, we don't need that many seconds (usually 1 or 2 at most).
> For some reason I thought this was for passing the current time of a
> stamp.

It's an absolute time stamp, but users of this interface are more 
interested in the time difference between events and how they change over 
time. E.g. NTP time stamps are 64bit fixed point values with a 32bit 
integral part.
This is not an interface to read the current system time, so 32bit will 
continue to work.

bye, Roman

Re: [PATCH] LinuxPPS (with new syscalls API)

[Robert Hancock]

David Woodhouse wrote:
> On Tue, 2007-06-26 at 19:06 +0200, Rodolfo Giometti wrote:
>> On Tue, Jun 26, 2007 at 11:57:07AM +0100, David Woodhouse wrote:
>>> Your syscalls blindly dereference userspace pointers instead of using
>>> copy_{to,from} user.
>> I use access_ok() to test userspace addresses. It should be ok,
>> shouldn't it?
> 
> No; it's racy. You must use copy_from_user() and copy_to_user().

Not only is it racy, but it doesn't even do all of the checks that 
copy_to/from_user does. access_ok only validates that the region given 
is potentially valid, not that it actually is. Using access_ok only 
allows you to use __copy_to/from_user instead, which skips the same 
checks that access_ok does - not worth it unless you do repeated copies 
to/from the same region of memory.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/