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 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
  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
 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) */
 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 */