/*
 * 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;
};

#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 *)

#endif /* _PPS_H_ */