xref: /linux/include/linux/pps_kernel.h (revision 74ba9207)
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 
20 struct pps_device;
21 
22 /* The specific PPS source info */
23 struct 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 
35 struct 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 */
43 struct 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 	wait_queue_head_t queue;		/* PPS event queue */
56 
57 	unsigned int id;			/* PPS source unique ID */
58 	void const *lookup_cookie;		/* For pps_lookup_dev() only */
59 	struct cdev cdev;
60 	struct device *dev;
61 	struct fasync_struct *async_queue;	/* fasync method */
62 	spinlock_t lock;
63 };
64 
65 /*
66  * Global variables
67  */
68 
69 extern 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 
78 extern int pps_register_cdev(struct pps_device *pps);
79 extern void pps_unregister_cdev(struct pps_device *pps);
80 
81 /*
82  * Exported functions
83  */
84 
85 extern struct pps_device *pps_register_source(
86 		struct pps_source_info *info, int default_params);
87 extern void pps_unregister_source(struct pps_device *pps);
88 extern 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 */
91 struct pps_device *pps_lookup_dev(void const *cookie);
92 
timespec_to_pps_ktime(struct pps_ktime * kt,struct timespec64 ts)93 static 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 
pps_get_ts(struct pps_event_time * ts)100 static inline void pps_get_ts(struct pps_event_time *ts)
101 {
102 	struct system_time_snapshot snap;
103 
104 	ktime_get_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) */
pps_sub_ts(struct pps_event_time * ts,struct timespec64 delta)112 static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
113 {
114 	ts->ts_real = timespec64_sub(ts->ts_real, 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