LXR linux/drivers/ptp/ptp

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * PTP 1588 clock support - private declarations for the core module.
   4 *
   5 * Copyright (C) 2010 OMICRON electronics GmbH
   6 */
   7#ifndef _PTP_PRIVATE_H_
   8#define _PTP_PRIVATE_H_
   9
  10#include <linux/cdev.h>
  11#include <linux/device.h>
  12#include <linux/kthread.h>
  13#include <linux/mutex.h>
  14#include <linux/posix-clock.h>
  15#include <linux/ptp_clock.h>
  16#include <linux/ptp_clock_kernel.h>
  17#include <linux/time.h>
  18
  19#define PTP_MAX_TIMESTAMPS 128
  20#define PTP_BUF_TIMESTAMPS 30
  21
  22struct timestamp_event_queue {
  23        struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
  24        int head;
  25        int tail;
  26        spinlock_t lock;
  27};
  28
  29struct ptp_clock {
  30        struct posix_clock clock;
  31        struct device *dev;
  32        struct ptp_clock_info *info;
  33        dev_t devid;
  34        int index; /* index into clocks.map */
  35        struct pps_device *pps_source;
  36        long dialed_frequency; /* remembers the frequency adjustment */
  37        struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
  38        struct mutex tsevq_mux; /* one process at a time reading the fifo */
  39        struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
  40        wait_queue_head_t tsev_wq;
  41        int defunct; /* tells readers to go away when clock is being removed */
  42        struct device_attribute *pin_dev_attr;
  43        struct attribute **pin_attr;
  44        struct attribute_group pin_attr_group;
  45        /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
  46        const struct attribute_group *pin_attr_groups[2];
  47        struct kthread_worker *kworker;
  48        struct kthread_delayed_work aux_work;
  49};
  50
  51/*
  52 * The function queue_cnt() is safe for readers to call without
  53 * holding q->lock. Readers use this function to verify that the queue
  54 * is nonempty before proceeding with a dequeue operation. The fact
  55 * that a writer might concurrently increment the tail does not
  56 * matter, since the queue remains nonempty nonetheless.
  57 */
  58static inline int queue_cnt(struct timestamp_event_queue *q)
  59{
  60        int cnt = q->tail - q->head;
  61        return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
  62}
  63
  64/*
  65 * see ptp_chardev.c
  66 */
  67
  68/* caller must hold pincfg_mux */
  69int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  70                    enum ptp_pin_function func, unsigned int chan);
  71
  72long ptp_ioctl(struct posix_clock *pc,
  73               unsigned int cmd, unsigned long arg);
  74
  75int ptp_open(struct posix_clock *pc, fmode_t fmode);
  76
  77ssize_t ptp_read(struct posix_clock *pc,
  78                 uint flags, char __user *buf, size_t cnt);
  79
  80__poll_t ptp_poll(struct posix_clock *pc,
  81              struct file *fp, poll_table *wait);
  82
  83/*
  84 * see ptp_sysfs.c
  85 */
  86
  87extern const struct attribute_group *ptp_groups[];
  88
  89int ptp_populate_pin_groups(struct ptp_clock *ptp);
  90void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
  91
  92#endif
  93