/*
* PPS API kernel header
*
* Copyright (C) 2009 Rodolfo Giometti <[email protected]>
*
* 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 LINUX_PPS_KERNEL_H
#define LINUX_PPS_KERNEL_H

#include <linux/pps.h>

#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/time.h>

/*
* Global defines
*/

struct pps_device;

/* The specific PPS source info */
struct pps_source_info {
char name[PPS_MAX_NAME_LEN]; /* simbolic name */
char path[PPS_MAX_NAME_LEN]; /* path of connected device */
int mode; /* PPS's allowed mode */

void (*echo)(struct pps_device *pps,
int event, void *data); /* PPS echo function */

struct module *owner;
struct device *dev; /* Parent device for device_create */
};

struct pps_event_time {
#ifdef CONFIG_NTP_PPS
struct timespec ts_raw;
#endif /* CONFIG_NTP_PPS */
struct timespec ts_real;
};

/* The main struct */
struct pps_device {
struct pps_source_info info; /* PSS source info */

struct pps_kparams params; /* PPS's current params */

__u32 assert_sequence; /* PPS' assert event seq # */
__u32 clear_sequence; /* PPS' clear event seq # */
struct pps_ktime assert_tu;
struct pps_ktime clear_tu;
int current_mode; /* PPS mode at event time */

unsigned int last_ev; /* last PPS event id */
wait_queue_head_t queue; /* PPS event queue */

unsigned int id; /* PPS source unique ID */
void const *lookup_cookie; /* pps_lookup_dev only */
struct cdev cdev;
struct device *dev;
struct fasync_struct *async_queue; /* fasync method */
spinlock_t lock;
};

/*
* Global variables
*/

extern const struct attribute_group *pps_groups[];

/*
* Internal functions.
*
* These are not actually part of the exported API, but this is a
* convenient header file to put them in.
*/

extern int pps_register_cdev(struct pps_device *pps);
extern void pps_unregister_cdev(struct pps_device *pps);

/*
* Exported functions
*/

extern struct pps_device *pps_register_source(
struct pps_source_info *info, int default_params);
extern void pps_unregister_source(struct pps_device *pps);
extern void pps_event(struct pps_device *pps,
struct pps_event_time *ts, int event, void *data);
/* Look up a pps device by magic cookie */
struct pps_device *pps_lookup_dev(void const *cookie);

static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
struct timespec ts)
{
kt->sec = ts.tv_sec;
kt->nsec = ts.tv_nsec;
}

#ifdef CONFIG_NTP_PPS

static inline void pps_get_ts(struct pps_event_time *ts)
{
getnstime_raw_and_real(&ts->ts_raw, &ts->ts_real);
}

#else /* CONFIG_NTP_PPS */

static inline void pps_get_ts(struct pps_event_time *ts)
{
getnstimeofday(&ts->ts_real);
}

#endif /* CONFIG_NTP_PPS */

/* Subtract known time delay from PPS event time(s) */
static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
{
ts->ts_real = timespec_sub(ts->ts_real, delta);
#ifdef CONFIG_NTP_PPS
ts->ts_raw = timespec_sub(ts->ts_raw, delta);
#endif
}

#endif /* LINUX_PPS_KERNEL_H */