LXR linux/include/uapi/linux/pps.h

   1/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
   2/*
   3 * PPS API header
   4 *
   5 * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
   6 *
   7 *   This program is free software; you can redistribute it and/or modify
   8 *   it under the terms of the GNU General Public License as published by
   9 *   the Free Software Foundation; either version 2 of the License, or
  10 *   (at your option) any later version.
  11 *
  12 *   This program is distributed in the hope that it will be useful,
  13 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 *   GNU General Public License for more details.
  16 *
  17 *   You should have received a copy of the GNU General Public License
  18 *   along with this program; if not, write to the Free Software
  19 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22
  23#ifndef _PPS_H_
  24#define _PPS_H_
  25
  26#include <linux/types.h>
  27
  28#define PPS_VERSION             "5.3.6"
  29#define PPS_MAX_SOURCES         16              /* should be enough... */
  30
  31/* Implementation note: the logical states ``assert'' and ``clear''
  32 * are implemented in terms of the chip register, i.e. ``assert''
  33 * means the bit is set.  */
  34
  35/*
  36 * 3.2 New data structures
  37 */
  38
  39#define PPS_API_VERS_1          1
  40#define PPS_API_VERS            PPS_API_VERS_1  /* we use API version 1 */
  41#define PPS_MAX_NAME_LEN        32
  42
  43/* 32-bit vs. 64-bit compatibility.
  44 *
  45 * 0n i386, the alignment of a uint64_t is only 4 bytes, while on most other
  46 * architectures it's 8 bytes. On i386, there will be no padding between the
  47 * two consecutive 'struct pps_ktime' members of struct pps_kinfo and struct
  48 * pps_kparams. But on most platforms there will be padding to ensure correct
  49 * alignment.
  50 *
  51 * The simple fix is probably to add an explicit padding.
  52 *                                                      [David Woodhouse]
  53 */
  54struct pps_ktime {
  55        __s64 sec;
  56        __s32 nsec;
  57        __u32 flags;
  58};
  59
  60struct pps_ktime_compat {
  61        __s64 sec;
  62        __s32 nsec;
  63        __u32 flags;
  64} __attribute__((packed, aligned(4)));
  65#define PPS_TIME_INVALID        (1<<0)  /* used to specify timeout==NULL */
  66
  67struct pps_kinfo {
  68        __u32 assert_sequence;          /* seq. num. of assert event */
  69        __u32 clear_sequence;           /* seq. num. of clear event */
  70        struct pps_ktime assert_tu;     /* time of assert event */
  71        struct pps_ktime clear_tu;      /* time of clear event */
  72        int current_mode;               /* current mode bits */
  73};
  74
  75struct pps_kinfo_compat {
  76        __u32 assert_sequence;                  /* seq. num. of assert event */
  77        __u32 clear_sequence;                   /* seq. num. of clear event */
  78        struct pps_ktime_compat assert_tu;      /* time of assert event */
  79        struct pps_ktime_compat clear_tu;       /* time of clear event */
  80        int current_mode;                       /* current mode bits */
  81};
  82
  83struct pps_kparams {
  84        int api_version;                /* API version # */
  85        int mode;                       /* mode bits */
  86        struct pps_ktime assert_off_tu; /* offset compensation for assert */
  87        struct pps_ktime clear_off_tu;  /* offset compensation for clear */
  88};
  89
  90/*
  91 * 3.3 Mode bit definitions
  92 */
  93
  94/* Device/implementation parameters */
  95#define PPS_CAPTUREASSERT       0x01    /* capture assert events */
  96#define PPS_CAPTURECLEAR        0x02    /* capture clear events */
  97#define PPS_CAPTUREBOTH         0x03    /* capture assert and clear events */
  98
  99#define PPS_OFFSETASSERT        0x10    /* apply compensation for assert event */
 100#define PPS_OFFSETCLEAR         0x20    /* apply compensation for clear event */
 101
 102#define PPS_CANWAIT             0x100   /* can we wait for an event? */
 103#define PPS_CANPOLL             0x200   /* bit reserved for future use */
 104
 105/* Kernel actions */
 106#define PPS_ECHOASSERT          0x40    /* feed back assert event to output */
 107#define PPS_ECHOCLEAR           0x80    /* feed back clear event to output */
 108
 109/* Timestamp formats */
 110#define PPS_TSFMT_TSPEC         0x1000  /* select timespec format */
 111#define PPS_TSFMT_NTPFP         0x2000  /* select NTP format */
 112
 113/*
 114 * 3.4.4 New functions: disciplining the kernel timebase
 115 */
 116
 117/* Kernel consumers */
 118#define PPS_KC_HARDPPS          0       /* hardpps() (or equivalent) */
 119#define PPS_KC_HARDPPS_PLL      1       /* hardpps() constrained to
 120                                           use a phase-locked loop */
 121#define PPS_KC_HARDPPS_FLL      2       /* hardpps() constrained to
 122                                           use a frequency-locked loop */
 123/*
 124 * Here begins the implementation-specific part!
 125 */
 126
 127struct pps_fdata {
 128        struct pps_kinfo info;
 129        struct pps_ktime timeout;
 130};
 131
 132struct pps_fdata_compat {
 133        struct pps_kinfo_compat info;
 134        struct pps_ktime_compat timeout;
 135};
 136
 137struct pps_bind_args {
 138        int tsformat;   /* format of time stamps */
 139        int edge;       /* selected event type */
 140        int consumer;   /* selected kernel consumer */
 141};
 142
 143#include <linux/ioctl.h>
 144
 145#define PPS_GETPARAMS           _IOR('p', 0xa1, struct pps_kparams *)
 146#define PPS_SETPARAMS           _IOW('p', 0xa2, struct pps_kparams *)
 147#define PPS_GETCAP              _IOR('p', 0xa3, int *)
 148#define PPS_FETCH               _IOWR('p', 0xa4, struct pps_fdata *)
 149#define PPS_KC_BIND             _IOW('p', 0xa5, struct pps_bind_args *)
 150
 151#endif /* _PPS_H_ */
 152