xref: /openbmc/linux/drivers/ptp/ptp_private.h (revision c8608558)
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 	struct mutex 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  */
queue_cnt(const struct timestamp_event_queue * q)79 static inline int queue_cnt(const struct timestamp_event_queue *q)
80 {
81 	/*
82 	 * Paired with WRITE_ONCE() in enqueue_external_timestamp(),
83 	 * ptp_read(), extts_fifo_show().
84 	 */
85 	int cnt = READ_ONCE(q->tail) - READ_ONCE(q->head);
86 	return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
87 }
88 
89 /* Check if ptp virtual clock is in use */
ptp_vclock_in_use(struct ptp_clock * ptp)90 static inline bool ptp_vclock_in_use(struct ptp_clock *ptp)
91 {
92 	bool in_use = false;
93 
94 	if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
95 		return true;
96 
97 	if (!ptp->is_virtual_clock && ptp->n_vclocks)
98 		in_use = true;
99 
100 	mutex_unlock(&ptp->n_vclocks_mux);
101 
102 	return in_use;
103 }
104 
105 /* Check if ptp clock shall be free running */
ptp_clock_freerun(struct ptp_clock * ptp)106 static inline bool ptp_clock_freerun(struct ptp_clock *ptp)
107 {
108 	if (ptp->has_cycles)
109 		return false;
110 
111 	return ptp_vclock_in_use(ptp);
112 }
113 
114 extern struct class *ptp_class;
115 
116 /*
117  * see ptp_chardev.c
118  */
119 
120 /* caller must hold pincfg_mux */
121 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
122 		    enum ptp_pin_function func, unsigned int chan);
123 
124 long ptp_ioctl(struct posix_clock *pc,
125 	       unsigned int cmd, unsigned long arg);
126 
127 int ptp_open(struct posix_clock *pc, fmode_t fmode);
128 
129 ssize_t ptp_read(struct posix_clock *pc,
130 		 uint flags, char __user *buf, size_t cnt);
131 
132 __poll_t ptp_poll(struct posix_clock *pc,
133 	      struct file *fp, poll_table *wait);
134 
135 /*
136  * see ptp_sysfs.c
137  */
138 
139 extern const struct attribute_group *ptp_groups[];
140 
141 int ptp_populate_pin_groups(struct ptp_clock *ptp);
142 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
143 
144 struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock);
145 void ptp_vclock_unregister(struct ptp_vclock *vclock);
146 #endif
147