xref: /openbmc/linux/drivers/ptp/ptp_private.h (revision 842ed298)
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 
22 struct timestamp_event_queue {
23 	struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
24 	int head;
25 	int tail;
26 	spinlock_t lock;
27 };
28 
29 struct 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  */
58 static inline int queue_cnt(struct timestamp_event_queue *q)
59 {
60 	int cnt = q->tail - q->head;
61 	return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
62 }
63 
64 /*
65  * see ptp_chardev.c
66  */
67 
68 /* caller must hold pincfg_mux */
69 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
70 		    enum ptp_pin_function func, unsigned int chan);
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 
77 ssize_t ptp_read(struct posix_clock *pc,
78 		 uint flags, char __user *buf, size_t cnt);
79 
80 __poll_t ptp_poll(struct posix_clock *pc,
81 	      struct file *fp, poll_table *wait);
82 
83 /*
84  * see ptp_sysfs.c
85  */
86 
87 extern const struct attribute_group *ptp_groups[];
88 
89 int ptp_populate_pin_groups(struct ptp_clock *ptp);
90 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
91 
92 #endif
93