1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * PPS API kernel header
4 *
5 * Copyright (C) 2009 Rodolfo Giometti <giometti@linux.it>
6 */
7
8#ifndef LINUX_PPS_KERNEL_H
9#define LINUX_PPS_KERNEL_H
10
11#include <linux/pps.h>
12#include <linux/cdev.h>
13#include <linux/device.h>
14#include <linux/time.h>
15
16/*
17 * Global defines
18 */
19
20struct pps_device;
21
22/* The specific PPS source info */
23struct pps_source_info {
24 char name[PPS_MAX_NAME_LEN]; /* symbolic name */
25 char path[PPS_MAX_NAME_LEN]; /* path of connected device */
26 int mode; /* PPS allowed mode */
27
28 void (*echo)(struct pps_device *pps,
29 int event, void *data); /* PPS echo function */
30
31 struct module *owner;
32 struct device *dev; /* Parent device for device_create */
33};
34
35struct pps_event_time {
36#ifdef CONFIG_NTP_PPS
37 struct timespec64 ts_raw;
38#endif /* CONFIG_NTP_PPS */
39 struct timespec64 ts_real;
40};
41
42/* The main struct */
43struct pps_device {
44 struct pps_source_info info; /* PSS source info */
45
46 struct pps_kparams params; /* PPS current params */
47
48 __u32 assert_sequence; /* PPS assert event seq # */
49 __u32 clear_sequence; /* PPS clear event seq # */
50 struct pps_ktime assert_tu;
51 struct pps_ktime clear_tu;
52 int current_mode; /* PPS mode at event time */
53
54 unsigned int last_ev; /* last PPS event id */
55 unsigned int last_fetched_ev; /* last fetched PPS event id */
56 wait_queue_head_t queue; /* PPS event queue */
57
58 unsigned int id; /* PPS source unique ID */
59 void const *lookup_cookie; /* For pps_lookup_dev() only */
60 struct device dev;
61 struct fasync_struct *async_queue; /* fasync method */
62 spinlock_t lock;
63};
64
65/*
66 * Global variables
67 */
68
69extern const struct attribute_group *pps_groups[];
70
71/*
72 * Internal functions.
73 *
74 * These are not actually part of the exported API, but this is a
75 * convenient header file to put them in.
76 */
77
78extern int pps_register_cdev(struct pps_device *pps);
79extern void pps_unregister_cdev(struct pps_device *pps);
80
81/*
82 * Exported functions
83 */
84
85extern struct pps_device *pps_register_source(
86 struct pps_source_info *info, int default_params);
87extern void pps_unregister_source(struct pps_device *pps);
88extern void pps_event(struct pps_device *pps,
89 struct pps_event_time *ts, int event, void *data);
90/* Look up a pps_device by magic cookie */
91struct pps_device *pps_lookup_dev(void const *cookie);
92
93static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
94 struct timespec64 ts)
95{
96 kt->sec = ts.tv_sec;
97 kt->nsec = ts.tv_nsec;
98}
99
100static inline void pps_get_ts(struct pps_event_time *ts)
101{
102 struct system_time_snapshot snap;
103
104 ktime_get_snapshot(systime_snapshot: &snap);
105 ts->ts_real = ktime_to_timespec64(snap.real);
106#ifdef CONFIG_NTP_PPS
107 ts->ts_raw = ktime_to_timespec64(snap.raw);
108#endif
109}
110
111/* Subtract known time delay from PPS event time(s) */
112static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
113{
114 ts->ts_real = timespec64_sub(lhs: ts->ts_real, rhs: delta);
115#ifdef CONFIG_NTP_PPS
116 ts->ts_raw = timespec64_sub(ts->ts_raw, delta);
117#endif
118}
119
120#endif /* LINUX_PPS_KERNEL_H */
121