xref: /openbmc/linux/drivers/ptp/ptp_private.h (revision f71a261a)
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 #define PTP_DEFAULT_MAX_VCLOCKS 20
22 
23 struct timestamp_event_queue {
24 	struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
25 	int head;
26 	int tail;
27 	spinlock_t lock;
28 };
29 
30 struct ptp_clock {
31 	struct posix_clock clock;
32 	struct device dev;
33 	struct ptp_clock_info *info;
34 	dev_t devid;
35 	int index; /* index into clocks.map */
36 	struct pps_device *pps_source;
37 	long dialed_frequency; /* remembers the frequency adjustment */
38 	struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
39 	struct mutex tsevq_mux; /* one process at a time reading the fifo */
40 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
41 	wait_queue_head_t tsev_wq;
42 	int defunct; /* tells readers to go away when clock is being removed */
43 	struct device_attribute *pin_dev_attr;
44 	struct attribute **pin_attr;
45 	struct attribute_group pin_attr_group;
46 	/* 1st entry is a pointer to the real group, 2nd is NULL terminator */
47 	const struct attribute_group *pin_attr_groups[2];
48 	struct kthread_worker *kworker;
49 	struct kthread_delayed_work aux_work;
50 	unsigned int max_vclocks;
51 	unsigned int n_vclocks;
52 	int *vclock_index;
53 	struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
54 	bool is_virtual_clock;
55 	bool has_cycles;
56 };
57 
58 #define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
59 #define cc_to_vclock(d) container_of((d), struct ptp_vclock, cc)
60 #define dw_to_vclock(d) container_of((d), struct ptp_vclock, refresh_work)
61 
62 struct ptp_vclock {
63 	struct ptp_clock *pclock;
64 	struct ptp_clock_info info;
65 	struct ptp_clock *clock;
66 	struct hlist_node vclock_hash_node;
67 	struct cyclecounter cc;
68 	struct timecounter tc;
69 	spinlock_t lock;	/* protects tc/cc */
70 };
71 
72 /*
73  * The function queue_cnt() is safe for readers to call without
74  * holding q->lock. Readers use this function to verify that the queue
75  * is nonempty before proceeding with a dequeue operation. The fact
76  * that a writer might concurrently increment the tail does not
77  * matter, since the queue remains nonempty nonetheless.
78  */
79 static inline int queue_cnt(struct timestamp_event_queue *q)
80 {
81 	int cnt = q->tail - q->head;
82 	return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
83 }
84 
85 /* Check if ptp virtual clock is in use */
86 static inline bool ptp_vclock_in_use(struct ptp_clock *ptp)
87 {
88 	bool in_use = false;
89 
90 	if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
91 		return true;
92 
93 	if (!ptp->is_virtual_clock && ptp->n_vclocks)
94 		in_use = true;
95 
96 	mutex_unlock(&ptp->n_vclocks_mux);
97 
98 	return in_use;
99 }
100 
101 /* Check if ptp clock shall be free running */
102 static inline bool ptp_clock_freerun(struct ptp_clock *ptp)
103 {
104 	if (ptp->has_cycles)
105 		return false;
106 
107 	return ptp_vclock_in_use(ptp);
108 }
109 
110 extern struct class *ptp_class;
111 
112 /*
113  * see ptp_chardev.c
114  */
115 
116 /* caller must hold pincfg_mux */
117 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
118 		    enum ptp_pin_function func, unsigned int chan);
119 
120 long ptp_ioctl(struct posix_clock *pc,
121 	       unsigned int cmd, unsigned long arg);
122 
123 int ptp_open(struct posix_clock *pc, fmode_t fmode);
124 
125 ssize_t ptp_read(struct posix_clock *pc,
126 		 uint flags, char __user *buf, size_t cnt);
127 
128 __poll_t ptp_poll(struct posix_clock *pc,
129 	      struct file *fp, poll_table *wait);
130 
131 /*
132  * see ptp_sysfs.c
133  */
134 
135 extern const struct attribute_group *ptp_groups[];
136 
137 int ptp_populate_pin_groups(struct ptp_clock *ptp);
138 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
139 
140 struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock);
141 void ptp_vclock_unregister(struct ptp_vclock *vclock);
142 #endif
143