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
34 struct pps_device;
35
36 /* The specific PPS source info */
37 struct 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
49 struct pps_event_time {
50 #ifdef CONFIG_NTP_PPS
51 struct timespec64 ts_raw;
52 #endif /* CONFIG_NTP_PPS */
53 struct timespec64 ts_real;
54 };
55
56 /* The main struct */
57 struct 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
83 extern 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
92 extern int pps_register_cdev(struct pps_device *pps);
93 extern void pps_unregister_cdev(struct pps_device *pps);
94
95 /*
96 * Exported functions
97 */
98
99 extern struct pps_device *pps_register_source(
100 struct pps_source_info *info, int default_params);
101 extern void pps_unregister_source(struct pps_device *pps);
102 extern 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 */
105 struct pps_device *pps_lookup_dev(void const *cookie);
106
timespec_to_pps_ktime(struct pps_ktime * kt,struct timespec64 ts)107 static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
108 struct timespec64 ts)
109 {
110 kt->sec = ts.tv_sec;
111 kt->nsec = ts.tv_nsec;
112 }
113
pps_get_ts(struct pps_event_time * ts)114 static inline void pps_get_ts(struct pps_event_time *ts)
115 {
116 struct system_time_snapshot snap;
117
118 ktime_get_snapshot(&snap);
119 ts->ts_real = ktime_to_timespec64(snap.real);
120 #ifdef CONFIG_NTP_PPS
121 ts->ts_raw = ktime_to_timespec64(snap.raw);
122 #endif
123 }
124
125 /* Subtract known time delay from PPS event time(s) */
pps_sub_ts(struct pps_event_time * ts,struct timespec64 delta)126 static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
127 {
128 ts->ts_real = timespec64_sub(ts->ts_real, delta);
129 #ifdef CONFIG_NTP_PPS
130 ts->ts_raw = timespec64_sub(ts->ts_raw, delta);
131 #endif
132 }
133
134 #endif /* LINUX_PPS_KERNEL_H */
135
136