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      1 /*
      2  * PPS API header
      3  *
      4  * Copyright (C) 2005-2009   Rodolfo Giometti <giometti (at) 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 #define PPS_TIME_INVALID	(1<<0)	/* used to specify timeout==NULL */
     59 
     60 struct 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 
     68 struct 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 
    112 struct pps_fdata {
    113 	struct pps_kinfo info;
    114 	struct pps_ktime timeout;
    115 };
    116 
    117 struct pps_bind_args {
    118 	int tsformat;	/* format of time stamps */
    119 	int edge;	/* selected event type */
    120 	int consumer;	/* selected kernel consumer */
    121 };
    122 
    123 #include <linux/ioctl.h>
    124 
    125 #define PPS_GETPARAMS		_IOR('p', 0xa1, struct pps_kparams *)
    126 #define PPS_SETPARAMS		_IOW('p', 0xa2, struct pps_kparams *)
    127 #define PPS_GETCAP		_IOR('p', 0xa3, int *)
    128 #define PPS_FETCH		_IOWR('p', 0xa4, struct pps_fdata *)
    129 #define PPS_KC_BIND		_IOW('p', 0xa5, struct pps_bind_args *)
    130 
    131 #endif /* _PPS_H_ */
    132