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ptp_private.h
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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 
36  int head;
37  int tail;
39 };
40 
41 struct ptp_clock {
43  struct device *dev;
46  int index; /* index into clocks.map */
48  long dialed_frequency; /* remembers the frequency adjustment */
49  struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
50  struct mutex tsevq_mux; /* one process at a time reading the fifo */
52  int defunct; /* tells readers to go away when clock is being removed */
53 };
54 
55 /*
56  * The function queue_cnt() is safe for readers to call without
57  * holding q->lock. Readers use this function to verify that the queue
58  * is nonempty before proceeding with a dequeue operation. The fact
59  * that a writer might concurrently increment the tail does not
60  * matter, since the queue remains nonempty nonetheless.
61  */
62 static inline int queue_cnt(struct timestamp_event_queue *q)
63 {
64  int cnt = q->tail - q->head;
65  return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
66 }
67 
68 /*
69  * see ptp_chardev.c
70  */
71 
72 long ptp_ioctl(struct posix_clock *pc,
73  unsigned int cmd, unsigned long arg);
74 
75 int ptp_open(struct posix_clock *pc, fmode_t fmode);
76 
78  uint flags, char __user *buf, size_t cnt);
79 
80 uint ptp_poll(struct posix_clock *pc,
81  struct file *fp, poll_table *wait);
82 
83 /*
84  * see ptp_sysfs.c
85  */
86 
87 extern struct device_attribute ptp_dev_attrs[];
88 
89 int ptp_cleanup_sysfs(struct ptp_clock *ptp);
90 
91 int ptp_populate_sysfs(struct ptp_clock *ptp);
92 
93 #endif