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  */
  54 struct pps_ktime {
  55         __s64 sec;
  56         __s32 nsec;
  57         __u32 flags;
  58 };
  59
  60 struct 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
  67 struct 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
  75 struct 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
  83 struct 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
 127 struct pps_fdata {
 128         struct pps_kinfo info;
 129         struct pps_ktime timeout;
 130 };
 131
 132 struct pps_fdata_compat {
 133         struct pps_kinfo_compat info;
 134         struct pps_ktime_compat timeout;
 135 };
 136
 137 struct 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_ */