/*
   * PPS API header
   *
   * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it>
   *
   *   This program is free software; you can redistribute it and/or modify
   *   it under the terms of the GNU General Public License as published by
   *   the Free Software Foundation; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *   GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program; if not, write to the Free Software
   *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  
  #ifndef _PPS_H_
  #define _PPS_H_
  
  #include <linux/types.h>
  
  #define PPS_VERSION		"5.3.6"
  #define PPS_MAX_SOURCES		16		/* should be enough... */
  
  /* Implementation note: the logical states ``assert'' and ``clear''
   * are implemented in terms of the chip register, i.e. ``assert''
   * means the bit is set.  */
  
  /*
   * 3.2 New data structures
   */
  
  #define PPS_API_VERS_1		1
  #define PPS_API_VERS		PPS_API_VERS_1	/* we use API version 1 */
  #define PPS_MAX_NAME_LEN	32
  
  /* 32-bit vs. 64-bit compatibility.
   *
   * 0n i386, the alignment of a uint64_t is only 4 bytes, while on most other
   * architectures it's 8 bytes. On i386, there will be no padding between the
   * two consecutive 'struct pps_ktime' members of struct pps_kinfo and struct
   * pps_kparams. But on most platforms there will be padding to ensure correct
   * alignment.
   *
   * The simple fix is probably to add an explicit padding.
   *					 		[David Woodhouse]
   */
  struct pps_ktime {
  	__s64 sec;
  	__s32 nsec;
  	__u32 flags;
  };
  #define PPS_TIME_INVALID	(1<<0)	/* used to specify timeout==NULL */
  
  struct pps_kinfo {
  	__u32 assert_sequence;		/* seq. num. of assert event */
  	__u32 clear_sequence; 		/* seq. num. of clear event */
  	struct pps_ktime assert_tu;	/* time of assert event */
  	struct pps_ktime clear_tu;	/* time of clear event */
  	int current_mode;		/* current mode bits */
  };
  
  struct pps_kparams {
  	int api_version;		/* API version # */
  	int mode;			/* mode bits */
  	struct pps_ktime assert_off_tu;	/* offset compensation for assert */
  	struct pps_ktime clear_off_tu;	/* offset compensation for clear */
  };
  
  /*
   * 3.3 Mode bit definitions
   */
  
  /* Device/implementation parameters */
  #define PPS_CAPTUREASSERT	0x01	/* capture assert events */
  #define PPS_CAPTURECLEAR	0x02	/* capture clear events */
  #define PPS_CAPTUREBOTH		0x03	/* capture assert and clear events */
  
  #define PPS_OFFSETASSERT	0x10	/* apply compensation for assert ev. */
  #define PPS_OFFSETCLEAR		0x20	/* apply compensation for clear ev. */
  
  #define PPS_CANWAIT		0x100	/* can we wait for an event? */
  #define PPS_CANPOLL		0x200	/* bit reserved for future use */
  
  /* Kernel actions */
  #define PPS_ECHOASSERT		0x40	/* feed back assert event to output */
  #define PPS_ECHOCLEAR		0x80	/* feed back clear event to output */
  
  /* Timestamp formats */
  #define PPS_TSFMT_TSPEC		0x1000	/* select timespec format */
  #define PPS_TSFMT_NTPFP		0x2000	/* select NTP format */
  
  /*
   * 3.4.4 New functions: disciplining the kernel timebase
   */
  
  /* Kernel consumers */
  #define PPS_KC_HARDPPS		0	/* hardpps() (or equivalent) */
  #define PPS_KC_HARDPPS_PLL	1	/* hardpps() constrained to
  					   use a phase-locked loop */
  #define PPS_KC_HARDPPS_FLL	2	/* hardpps() constrained to
  					   use a frequency-locked loop */
  /*
   * Here begins the implementation-specific part!
   */
  
  struct pps_fdata {
  	struct pps_kinfo info;
  	struct pps_ktime timeout;
  };
  
  struct pps_bind_args {
  	int tsformat;	/* format of time stamps */
  	int edge;	/* selected event type */
  	int consumer;	/* selected kernel consumer */
  };
  
  #include <linux/ioctl.h>
  
  #define PPS_GETPARAMS		_IOR('p', 0xa1, struct pps_kparams *)
  #define PPS_SETPARAMS		_IOW('p', 0xa2, struct pps_kparams *)
  #define PPS_GETCAP		_IOR('p', 0xa3, int *)
  #define PPS_FETCH		_IOWR('p', 0xa4, struct pps_fdata *)
  #define PPS_KC_BIND		_IOW('p', 0xa5, struct pps_bind_args *)
  
  #endif /* _PPS_H_ */