timepps.h

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/*
 * timepps.h -- PPS API main header
 *
 * Copyright (C) 2005-2007   Rodolfo Giometti <giometti@linux.it>
 * Copyright (C) 2009-2011   Alexander Gordeev <alex@gordick.net>
 *
 *   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.
 */
 
#ifndef _SYS_TIMEPPS_H_
#define _SYS_TIMEPPS_H_
 
#include <errno.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <linux/types.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;
    struct pps_kparams dummy;
 
    if (!handle) {
        errno = EINVAL;
        return -1;
    }
 
    /* First we check if current device is a valid PPS one by
     * doing a dummy PPS_GETPARAMS...
     */
    ret = ioctl(source, PPS_GETPARAMS, &dummy);
    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;
}
 
#ifdef PPS_KC_BIND
 
static __inline int time_pps_kcbind(pps_handle_t handle,
                    const int kernel_consumer,
                    const int edge, const int tsformat)
{
    struct pps_bind_args __bind_args;
 
    __bind_args.tsformat = tsformat;
    __bind_args.edge = edge;
    __bind_args.consumer = kernel_consumer;
 
    return ioctl(handle, PPS_KC_BIND, &__bind_args);
}
 
#else /* !PPS_KC_BIND */
 
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 /* PPS_KC_BIND */
 
#endif /* _SYS_TIMEPPS_H_ */