1 /*
2 * PTP 1588 clock support - private declarations for the core module.
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 #ifndef _PTP_PRIVATE_H_
21 #define _PTP_PRIVATE_H_
22
23 #include <linux/cdev.h>
24 #include <linux/device.h>
25 #include <linux/mutex.h>
26 #include <linux/posix-clock.h>
27 #include <linux/ptp_clock.h>
28 #include <linux/ptp_clock_kernel.h>
29 #include <linux/time.h>
30
31 #define PTP_MAX_TIMESTAMPS 128
32 #define PTP_BUF_TIMESTAMPS 30
33
34 struct timestamp_event_queue {
35 struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
36 int head;
37 int tail;
38 spinlock_t lock;
39 };
40
41 struct ptp_clock {
42 struct posix_clock clock;
43 struct device *dev;
44 struct ptp_clock_info *info;
45 dev_t devid;
46 int index; /* index into clocks.map */
47 struct pps_device *pps_source;
48 struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
49 struct mutex tsevq_mux; /* one process at a time reading the fifo */
50 wait_queue_head_t tsev_wq;
51 int defunct; /* tells readers to go away when clock is being removed */
52 };
53
54 /*
55 * The function queue_cnt() is safe for readers to call without
56 * holding q->lock. Readers use this function to verify that the queue
57 * is nonempty before proceeding with a dequeue operation. The fact
58 * that a writer might concurrently increment the tail does not
59 * matter, since the queue remains nonempty nonetheless.
60 */
queue_cnt(struct timestamp_event_queue * q)61 static inline int queue_cnt(struct timestamp_event_queue *q)
62 {
63 int cnt = q->tail - q->head;
64 return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
65 }
66
67 /*
68 * see ptp_chardev.c
69 */
70
71 long ptp_ioctl(struct posix_clock *pc,
72 unsigned int cmd, unsigned long arg);
73
74 int ptp_open(struct posix_clock *pc, fmode_t fmode);
75
76 ssize_t ptp_read(struct posix_clock *pc,
77 uint flags, char __user *buf, size_t cnt);
78
79 uint ptp_poll(struct posix_clock *pc,
80 struct file *fp, poll_table *wait);
81
82 /*
83 * see ptp_sysfs.c
84 */
85
86 extern struct device_attribute ptp_dev_attrs[];
87
88 int ptp_cleanup_sysfs(struct ptp_clock *ptp);
89
90 int ptp_populate_sysfs(struct ptp_clock *ptp);
91
92 #endif
93