LXR linux/include/linux/pps.h

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