[PATCH 2/7] PPS: userland header file for PPS API.

From: Rodolfo Giometti
Date: Thu Apr 10 2008 - 14:23:45 EST


This patch adds into the PPS's documentation directory a possible
implementation of the PPS API (RFC 2783) by using the LinuxPPS's char
devices.

This file is not just an example but it can be used into real
systems. :)

Signed-off-by: Rodolfo Giometti <giometti@xxxxxxxx>
---
Documentation/pps/timepps.h | 195 +++++++++++++++++++++++++++++++++++++++++++
1 files changed, 195 insertions(+), 0 deletions(-)
create mode 100644 Documentation/pps/timepps.h

diff --git a/Documentation/pps/timepps.h b/Documentation/pps/timepps.h
new file mode 100644
index 0000000..2372949
--- /dev/null
+++ b/Documentation/pps/timepps.h
@@ -0,0 +1,195 @@
+/*
+ * timepps.h -- PPS API main header
+ *
+ * Copyright (C) 2005-2007 Rodolfo Giometti <giometti@xxxxxxxx>
+ *
+ * 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>
+
+#define LINUXPPS 1 /* signal we are using LinuxPPS */
+
+/*
+ * New data structures
+ */
+
+struct ntp_fp {
+ unsigned int integral;
+ unsigned int fractional;
+};
+
+union pps_timeu {
+ struct timespec tspec;
+ struct ntp_fp ntpfp;
+ unsigned long longpad[3];
+};
+
+struct pps_info {
+ unsigned long assert_sequence; /* seq. num. of assert event */
+ unsigned long clear_sequence; /* seq. num. of clear event */
+ union pps_timeu assert_tu; /* time of assert event */
+ union pps_timeu clear_tu; /* time of clear event */
+ int current_mode; /* current mode bits */
+};
+
+struct pps_params {
+ int api_version; /* API version # */
+ int mode; /* mode bits */
+ union pps_timeu assert_off_tu; /* offset compensation for assert */
+ union pps_timeu clear_off_tu; /* offset compensation for clear */
+};
+
+typedef int pps_handle_t; /* represents a PPS source */
+typedef unsigned long pps_seq_t; /* sequence number */
+typedef struct ntp_fp ntp_fp_t; /* NTP-compatible time stamp */
+typedef union pps_timeu pps_timeu_t; /* generic data type for time stamps */
+typedef struct pps_info pps_info_t;
+typedef struct pps_params pps_params_t;
+
+#define assert_timestamp assert_tu.tspec
+#define clear_timestamp clear_tu.tspec
+
+#define assert_timestamp_ntpfp assert_tu.ntpfp
+#define clear_timestamp_ntpfp clear_tu.ntpfp
+
+#define assert_offset assert_off_tu.tspec
+#define clear_offset clear_off_tu.tspec
+
+#define assert_offset_ntpfp assert_off_tu.ntpfp
+#define clear_offset_ntpfp clear_off_tu.ntpfp
+
+/*
+ * The PPS API
+ */
+
+static __inline int time_pps_create(int source, pps_handle_t *handle)
+{
+ int ret;
+
+ if (!handle) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ /* First we check if current device is a PPS valid PPS one...
+ */
+ ret = ioctl(source, PPS_CHECK);
+ if (ret) {
+ errno = EOPNOTSUPP;
+ return -1;
+ }
+
+ /* ... then since in LinuxPPS there are no differences between a
+ * "PPS source" and a "PPS handle", we simply return the same value.
+ */
+ *handle = source;
+
+ return 0;
+}
+
+static __inline int time_pps_destroy(pps_handle_t handle)
+{
+ return close(handle);
+}
+
+static __inline int time_pps_getparams(pps_handle_t handle,
+ pps_params_t *ppsparams)
+{
+ int ret;
+ struct pps_kparams __ppsparams;
+
+ ret = ioctl(handle, PPS_GETPARAMS, &__ppsparams);
+
+ ppsparams->api_version = __ppsparams.api_version;
+ ppsparams->mode = __ppsparams.mode;
+ ppsparams->assert_off_tu.tspec.tv_sec = __ppsparams.assert_off_tu.sec;
+ ppsparams->assert_off_tu.tspec.tv_nsec = __ppsparams.assert_off_tu.nsec;
+ ppsparams->clear_off_tu.tspec.tv_sec = __ppsparams.clear_off_tu.sec;
+ ppsparams->clear_off_tu.tspec.tv_nsec = __ppsparams.clear_off_tu.nsec;
+
+ return ret;
+}
+
+static __inline int time_pps_setparams(pps_handle_t handle,
+ const pps_params_t *ppsparams)
+{
+ struct pps_kparams __ppsparams;
+
+ __ppsparams.api_version = ppsparams->api_version;
+ __ppsparams.mode = ppsparams->mode;
+ __ppsparams.assert_off_tu.sec = ppsparams->assert_off_tu.tspec.tv_sec;
+ __ppsparams.assert_off_tu.nsec = ppsparams->assert_off_tu.tspec.tv_nsec;
+ __ppsparams.clear_off_tu.sec = ppsparams->clear_off_tu.tspec.tv_sec;
+ __ppsparams.clear_off_tu.nsec = ppsparams->clear_off_tu.tspec.tv_nsec;
+
+ return ioctl(handle, PPS_SETPARAMS, &__ppsparams);
+}
+
+/* Get capabilities for handle */
+static __inline int time_pps_getcap(pps_handle_t handle, int *mode)
+{
+ return ioctl(handle, PPS_GETCAP, mode);
+}
+
+static __inline int time_pps_fetch(pps_handle_t handle, const int tsformat,
+ pps_info_t *ppsinfobuf,
+ const struct timespec *timeout)
+{
+ struct pps_fdata __fdata;
+ int ret;
+
+ /* Sanity checks */
+ if (tsformat != PPS_TSFMT_TSPEC) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ if (timeout) {
+ __fdata.timeout.sec = timeout->tv_sec;
+ __fdata.timeout.nsec = timeout->tv_nsec;
+ __fdata.timeout.flags = ~PPS_TIME_INVALID;
+ } else
+ __fdata.timeout.flags = PPS_TIME_INVALID;
+
+ ret = ioctl(handle, PPS_FETCH, &__fdata);
+
+ ppsinfobuf->assert_sequence = __fdata.info.assert_sequence;
+ ppsinfobuf->clear_sequence = __fdata.info.clear_sequence;
+ ppsinfobuf->assert_tu.tspec.tv_sec = __fdata.info.assert_tu.sec;
+ ppsinfobuf->assert_tu.tspec.tv_nsec = __fdata.info.assert_tu.nsec;
+ ppsinfobuf->clear_tu.tspec.tv_sec = __fdata.info.clear_tu.sec;
+ ppsinfobuf->clear_tu.tspec.tv_nsec = __fdata.info.clear_tu.nsec;
+ ppsinfobuf->current_mode = __fdata.info.current_mode;
+
+ return ret;
+}
+
+static __inline int time_pps_kcbind(pps_handle_t handle,
+ const int kernel_consumer,
+ const int edge, const int tsformat)
+{
+ /* LinuxPPS doesn't implement kernel consumer feature */
+ errno = EOPNOTSUPP;
+ return -1;
+}
+
+#endif /* _SYS_TIMEPPS_H_ */
--
1.5.4.3

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