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/kthread.h>
26 #include <linux/mutex.h>
27 #include <linux/posix-clock.h>
28 #include <linux/ptp_clock.h>
29 #include <linux/ptp_clock_kernel.h>
30 #include <linux/time.h>
31 
32 #define PTP_MAX_TIMESTAMPS 128
33 #define PTP_BUF_TIMESTAMPS 30
34 
35 struct timestamp_event_queue {
36 	struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
37 	int head;
38 	int tail;
39 	spinlock_t lock;
40 };
41 
42 struct ptp_clock {
43 	struct posix_clock clock;
44 	struct device dev;
45 	struct ptp_clock_info *info;
46 	dev_t devid;
47 	int index; /* index into clocks.map */
48 	struct pps_device *pps_source;
49 	long dialed_frequency; /* remembers the frequency adjustment */
50 	struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
51 	struct mutex tsevq_mux; /* one process at a time reading the fifo */
52 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
53 	wait_queue_head_t tsev_wq;
54 	int defunct; /* tells readers to go away when clock is being removed */
55 	struct device_attribute *pin_dev_attr;
56 	struct attribute **pin_attr;
57 	struct attribute_group pin_attr_group;
58 	/* 1st entry is a pointer to the real group, 2nd is NULL terminator */
59 	const struct attribute_group *pin_attr_groups[2];
60 	struct kthread_worker *kworker;
61 	struct kthread_delayed_work aux_work;
62 };
63 
64 /*
65  * The function queue_cnt() is safe for readers to call without
66  * holding q->lock. Readers use this function to verify that the queue
67  * is nonempty before proceeding with a dequeue operation. The fact
68  * that a writer might concurrently increment the tail does not
69  * matter, since the queue remains nonempty nonetheless.
70  */
queue_cnt(struct timestamp_event_queue * q)71 static inline int queue_cnt(struct timestamp_event_queue *q)
72 {
73 	int cnt = q->tail - q->head;
74 	return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
75 }
76 
77 /*
78  * see ptp_chardev.c
79  */
80 
81 /* caller must hold pincfg_mux */
82 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
83 		    enum ptp_pin_function func, unsigned int chan);
84 
85 long ptp_ioctl(struct posix_clock *pc,
86 	       unsigned int cmd, unsigned long arg);
87 
88 int ptp_open(struct posix_clock *pc, fmode_t fmode);
89 
90 ssize_t ptp_read(struct posix_clock *pc,
91 		 uint flags, char __user *buf, size_t cnt);
92 
93 __poll_t ptp_poll(struct posix_clock *pc,
94 	      struct file *fp, poll_table *wait);
95 
96 /*
97  * see ptp_sysfs.c
98  */
99 
100 extern const struct attribute_group *ptp_groups[];
101 
102 int ptp_populate_pin_groups(struct ptp_clock *ptp);
103 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
104 
105 #endif
106