1/*
2 * PPS API kernel header
3 *
4 * Copyright (C) 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#ifndef LINUX_PPS_KERNEL_H
22#define LINUX_PPS_KERNEL_H
23
24#include <linux/pps.h>
25
26#include <linux/cdev.h>
27#include <linux/device.h>
28#include <linux/time.h>
29
30/*
31 * Global defines
32 */
33
34struct pps_device;
35
36/* The specific PPS source info */
37struct pps_source_info {
38	char name[PPS_MAX_NAME_LEN];		/* simbolic name */
39	char path[PPS_MAX_NAME_LEN];		/* path of connected device */
40	int mode;				/* PPS's allowed mode */
41
42	void (*echo)(struct pps_device *pps,
43			int event, void *data);	/* PPS echo function */
44
45	struct module *owner;
46	struct device *dev;		/* Parent device for device_create */
47};
48
49struct pps_event_time {
50#ifdef CONFIG_NTP_PPS
51	struct timespec ts_raw;
52#endif /* CONFIG_NTP_PPS */
53	struct timespec ts_real;
54};
55
56/* The main struct */
57struct pps_device {
58	struct pps_source_info info;		/* PSS source info */
59
60	struct pps_kparams params;		/* PPS's current params */
61
62	__u32 assert_sequence;			/* PPS' assert event seq # */
63	__u32 clear_sequence;			/* PPS' clear event seq # */
64	struct pps_ktime assert_tu;
65	struct pps_ktime clear_tu;
66	int current_mode;			/* PPS mode at event time */
67
68	unsigned int last_ev;			/* last PPS event id */
69	wait_queue_head_t queue;		/* PPS event queue */
70
71	unsigned int id;			/* PPS source unique ID */
72	void const *lookup_cookie;		/* pps_lookup_dev only */
73	struct cdev cdev;
74	struct device *dev;
75	struct fasync_struct *async_queue;	/* fasync method */
76	spinlock_t lock;
77};
78
79/*
80 * Global variables
81 */
82
83extern const struct attribute_group *pps_groups[];
84
85/*
86 * Internal functions.
87 *
88 * These are not actually part of the exported API, but this is a
89 * convenient header file to put them in.
90 */
91
92extern int pps_register_cdev(struct pps_device *pps);
93extern void pps_unregister_cdev(struct pps_device *pps);
94
95/*
96 * Exported functions
97 */
98
99extern struct pps_device *pps_register_source(
100		struct pps_source_info *info, int default_params);
101extern void pps_unregister_source(struct pps_device *pps);
102extern void pps_event(struct pps_device *pps,
103		struct pps_event_time *ts, int event, void *data);
104/* Look up a pps device by magic cookie */
105struct pps_device *pps_lookup_dev(void const *cookie);
106
107static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
108		struct timespec ts)
109{
110	kt->sec = ts.tv_sec;
111	kt->nsec = ts.tv_nsec;
112}
113
114#ifdef CONFIG_NTP_PPS
115
116static inline void pps_get_ts(struct pps_event_time *ts)
117{
118	getnstime_raw_and_real(&ts->ts_raw, &ts->ts_real);
119}
120
121#else /* CONFIG_NTP_PPS */
122
123static inline void pps_get_ts(struct pps_event_time *ts)
124{
125	getnstimeofday(&ts->ts_real);
126}
127
128#endif /* CONFIG_NTP_PPS */
129
130/* Subtract known time delay from PPS event time(s) */
131static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
132{
133	ts->ts_real = timespec_sub(ts->ts_real, delta);
134#ifdef CONFIG_NTP_PPS
135	ts->ts_raw = timespec_sub(ts->ts_raw, delta);
136#endif
137}
138
139#endif /* LINUX_PPS_KERNEL_H */
140
141