include/linux/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
  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 device dev;
  60         struct fasync_struct *async_queue;      /* fasync method */
  61         spinlock_t lock;
  62 };
  63
  64 /*
  65  * Global variables
  66  */
  67
  68 extern const struct attribute_group *pps_groups[];
  69
  70 /*
  71  * Internal functions.
  72  *
  73  * These are not actually part of the exported API, but this is a
  74  * convenient header file to put them in.
  75  */
  76
  77 extern int pps_register_cdev(struct pps_device *pps);
  78 extern void pps_unregister_cdev(struct pps_device *pps);
  79
  80 /*
  81  * Exported functions
  82  */
  83
  84 extern struct pps_device *pps_register_source(
  85                 struct pps_source_info *info, int default_params);
  86 extern void pps_unregister_source(struct pps_device *pps);
  87 extern void pps_event(struct pps_device *pps,
  88                 struct pps_event_time *ts, int event, void *data);
  89 /* Look up a pps_device by magic cookie */
  90 struct pps_device *pps_lookup_dev(void const *cookie);
  91
  92 static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
  93                 struct timespec64 ts)
  94 {
  95         kt->sec = ts.tv_sec;
  96         kt->nsec = ts.tv_nsec;
  97 }
  98
  99 static inline void pps_get_ts(struct pps_event_time *ts)
 100 {
 101         struct system_time_snapshot snap;
 102
 103         ktime_get_snapshot(&snap);
 104         ts->ts_real = ktime_to_timespec64(snap.real);
 105 #ifdef CONFIG_NTP_PPS
 106         ts->ts_raw = ktime_to_timespec64(snap.raw);
 107 #endif
 108 }
 109
 110 /* Subtract known time delay from PPS event time(s) */
 111 static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec64 delta)
 112 {
 113         ts->ts_real = timespec64_sub(ts->ts_real, delta);
 114 #ifdef CONFIG_NTP_PPS
 115         ts->ts_raw = timespec64_sub(ts->ts_raw, delta);
 116 #endif
 117 }
 118
 119 #endif /* LINUX_PPS_KERNEL_H */