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#define PTP_DEFAULT_MAX_VCLOCKS 20
  22
  23struct timestamp_event_queue {
  24        struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
  25        int head;
  26        int tail;
  27        spinlock_t lock;
  28};
  29
  30struct ptp_clock {
  31        struct posix_clock clock;
  32        struct device dev;
  33        struct ptp_clock_info *info;
  34        dev_t devid;
  35        int index; /* index into clocks.map */
  36        struct pps_device *pps_source;
  37        long dialed_frequency; /* remembers the frequency adjustment */
  38        struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
  39        struct mutex tsevq_mux; /* one process at a time reading the fifo */
  40        struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
  41        wait_queue_head_t tsev_wq;
  42        int defunct; /* tells readers to go away when clock is being removed */
  43        struct device_attribute *pin_dev_attr;
  44        struct attribute **pin_attr;
  45        struct attribute_group pin_attr_group;
  46        /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
  47        const struct attribute_group *pin_attr_groups[2];
  48        struct kthread_worker *kworker;
  49        struct kthread_delayed_work aux_work;
  50        unsigned int max_vclocks;
  51        unsigned int n_vclocks;
  52        int *vclock_index;
  53        struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
  54        bool is_virtual_clock;
  55};
  56
  57#define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
  58#define cc_to_vclock(d) container_of((d), struct ptp_vclock, cc)
  59#define dw_to_vclock(d) container_of((d), struct ptp_vclock, refresh_work)
  60
  61struct ptp_vclock {
  62        struct ptp_clock *pclock;
  63        struct ptp_clock_info info;
  64        struct ptp_clock *clock;
  65        struct cyclecounter cc;
  66        struct timecounter tc;
  67        spinlock_t lock;        /* protects tc/cc */
  68};
  69
  70/*
  71 * The function queue_cnt() is safe for readers to call without
  72 * holding q->lock. Readers use this function to verify that the queue
  73 * is nonempty before proceeding with a dequeue operation. The fact
  74 * that a writer might concurrently increment the tail does not
  75 * matter, since the queue remains nonempty nonetheless.
  76 */
  77static inline int queue_cnt(struct timestamp_event_queue *q)
  78{
  79        int cnt = q->tail - q->head;
  80        return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
  81}
  82
  83/* Check if ptp virtual clock is in use */
  84static inline bool ptp_vclock_in_use(struct ptp_clock *ptp)
  85{
  86        bool in_use = false;
  87
  88        if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
  89                return true;
  90
  91        if (!ptp->is_virtual_clock && ptp->n_vclocks)
  92                in_use = true;
  93
  94        mutex_unlock(&ptp->n_vclocks_mux);
  95
  96        return in_use;
  97}
  98
  99extern struct class *ptp_class;
 100
 101/*
 102 * see ptp_chardev.c
 103 */
 104
 105/* caller must hold pincfg_mux */
 106int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 107                    enum ptp_pin_function func, unsigned int chan);
 108
 109long ptp_ioctl(struct posix_clock *pc,
 110               unsigned int cmd, unsigned long arg);
 111
 112int ptp_open(struct posix_clock *pc, fmode_t fmode);
 113
 114ssize_t ptp_read(struct posix_clock *pc,
 115                 uint flags, char __user *buf, size_t cnt);
 116
 117__poll_t ptp_poll(struct posix_clock *pc,
 118              struct file *fp, poll_table *wait);
 119
 120/*
 121 * see ptp_sysfs.c
 122 */
 123
 124extern const struct attribute_group *ptp_groups[];
 125
 126int ptp_populate_pin_groups(struct ptp_clock *ptp);
 127void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
 128
 129struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock);
 130void ptp_vclock_unregister(struct ptp_vclock *vclock);
 131#endif
 132