pps_kernel.h

  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(&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(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 */