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(const struct timestamp_event_queue *q)
59{
60	/*
61	 * Paired with WRITE_ONCE() in enqueue_external_timestamp(),
62	 * ptp_read(), extts_fifo_show().
63	 */
64	int cnt = READ_ONCE(q->tail) - READ_ONCE(q->head);
65	return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
66}
67
68/*
69 * see ptp_chardev.c
70 */
71
72/* caller must hold pincfg_mux */
73int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
74		    enum ptp_pin_function func, unsigned int chan);
75
76long ptp_ioctl(struct posix_clock *pc,
77	       unsigned int cmd, unsigned long arg);
78
79int ptp_open(struct posix_clock *pc, fmode_t fmode);
80
81ssize_t ptp_read(struct posix_clock *pc,
82		 uint flags, char __user *buf, size_t cnt);
83
84__poll_t ptp_poll(struct posix_clock *pc,
85	      struct file *fp, poll_table *wait);
86
87/*
88 * see ptp_sysfs.c
89 */
90
91extern const struct attribute_group *ptp_groups[];
92
93int ptp_populate_pin_groups(struct ptp_clock *ptp);
94void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
95
96#endif
97