include/uapi/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  */
  53 struct pps_ktime {
  54         __s64 sec;
  55         __s32 nsec;
  56         __u32 flags;
  57 };
  58
  59 struct pps_ktime_compat {
  60         __s64 sec;
  61         __s32 nsec;
  62         __u32 flags;
  63 } __attribute__((packed, aligned(4)));
  64 #define PPS_TIME_INVALID        (1<<0)  /* used to specify timeout==NULL */
  65
  66 struct pps_kinfo {
  67         __u32 assert_sequence;          /* seq. num. of assert event */
  68         __u32 clear_sequence;           /* seq. num. of clear event */
  69         struct pps_ktime assert_tu;     /* time of assert event */
  70         struct pps_ktime clear_tu;      /* time of clear event */
  71         int current_mode;               /* current mode bits */
  72 };
  73
  74 struct pps_kinfo_compat {
  75         __u32 assert_sequence;                  /* seq. num. of assert event */
  76         __u32 clear_sequence;                   /* seq. num. of clear event */
  77         struct pps_ktime_compat assert_tu;      /* time of assert event */
  78         struct pps_ktime_compat clear_tu;       /* time of clear event */
  79         int current_mode;                       /* current mode bits */
  80 };
  81
  82 struct pps_kparams {
  83         int api_version;                /* API version # */
  84         int mode;                       /* mode bits */
  85         struct pps_ktime assert_off_tu; /* offset compensation for assert */
  86         struct pps_ktime clear_off_tu;  /* offset compensation for clear */
  87 };
  88
  89 /*
  90  * 3.3 Mode bit definitions
  91  */
  92
  93 /* Device/implementation parameters */
  94 #define PPS_CAPTUREASSERT       0x01    /* capture assert events */
  95 #define PPS_CAPTURECLEAR        0x02    /* capture clear events */
  96 #define PPS_CAPTUREBOTH         0x03    /* capture assert and clear events */
  97
  98 #define PPS_OFFSETASSERT        0x10    /* apply compensation for assert event */
  99 #define PPS_OFFSETCLEAR         0x20    /* apply compensation for clear event */
 100
 101 #define PPS_CANWAIT             0x100   /* can we wait for an event? */
 102 #define PPS_CANPOLL             0x200   /* bit reserved for future use */
 103
 104 /* Kernel actions */
 105 #define PPS_ECHOASSERT          0x40    /* feed back assert event to output */
 106 #define PPS_ECHOCLEAR           0x80    /* feed back clear event to output */
 107
 108 /* Timestamp formats */
 109 #define PPS_TSFMT_TSPEC         0x1000  /* select timespec format */
 110 #define PPS_TSFMT_NTPFP         0x2000  /* select NTP format */
 111
 112 /*
 113  * 3.4.4 New functions: disciplining the kernel timebase
 114  */
 115
 116 /* Kernel consumers */
 117 #define PPS_KC_HARDPPS          0       /* hardpps() (or equivalent) */
 118 #define PPS_KC_HARDPPS_PLL      1       /* hardpps() constrained to
 119                                            use a phase-locked loop */
 120 #define PPS_KC_HARDPPS_FLL      2       /* hardpps() constrained to
 121                                            use a frequency-locked loop */
 122 /*
 123  * Here begins the implementation-specific part!
 124  */
 125
 126 struct pps_fdata {
 127         struct pps_kinfo info;
 128         struct pps_ktime timeout;
 129 };
 130
 131 struct pps_fdata_compat {
 132         struct pps_kinfo_compat info;
 133         struct pps_ktime_compat timeout;
 134 };
 135
 136 struct pps_bind_args {
 137         int tsformat;   /* format of time stamps */
 138         int edge;       /* selected event type */
 139         int consumer;   /* selected kernel consumer */
 140 };
 141
 142 #include <linux/ioctl.h>
 143
 144 #define PPS_GETPARAMS           _IOR('p', 0xa1, struct pps_kparams *)
 145 #define PPS_SETPARAMS           _IOW('p', 0xa2, struct pps_kparams *)
 146 #define PPS_GETCAP              _IOR('p', 0xa3, int *)
 147 #define PPS_FETCH               _IOWR('p', 0xa4, struct pps_fdata *)
 148 #define PPS_KC_BIND             _IOW('p', 0xa5, struct pps_bind_args *)
 149
 150 #endif /* _PPS_H_ */