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#include <linux/list.h>
19#include <linux/bitmap.h>
20#include <linux/debugfs.h>
21
22#define PTP_MAX_TIMESTAMPS 128
23#define PTP_BUF_TIMESTAMPS 30
24#define PTP_DEFAULT_MAX_VCLOCKS 20
25#define PTP_MAX_VCLOCKS_LIMIT (KMALLOC_MAX_SIZE/(sizeof(int)))
26#define PTP_MAX_CHANNELS 2048
27
28enum {
29 PTP_LOCK_PHYSICAL = 0,
30 PTP_LOCK_VIRTUAL,
31};
32
33struct timestamp_event_queue {
34 struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
35 int head;
36 int tail;
37 spinlock_t lock;
38 struct list_head qlist;
39 unsigned long *mask;
40 struct dentry *debugfs_instance;
41 struct debugfs_u32_array dfs_bitmap;
42};
43
44struct ptp_clock {
45 struct posix_clock clock;
46 struct device dev;
47 struct ptp_clock_info *info;
48 dev_t devid;
49 int index; /* index into clocks.map */
50 struct pps_device *pps_source;
51 long dialed_frequency; /* remembers the frequency adjustment */
52 struct list_head tsevqs; /* timestamp fifo list */
53 spinlock_t tsevqs_lock; /* protects tsevqs from concurrent access */
54 struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
55 wait_queue_head_t tsev_wq;
56 int defunct; /* tells readers to go away when clock is being removed */
57 struct device_attribute *pin_dev_attr;
58 struct attribute **pin_attr;
59 struct attribute_group pin_attr_group;
60 /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
61 const struct attribute_group *pin_attr_groups[2];
62 struct kthread_worker *kworker;
63 struct kthread_delayed_work aux_work;
64 unsigned int max_vclocks;
65 unsigned int n_vclocks;
66 int *vclock_index;
67 struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
68 bool is_virtual_clock;
69 bool has_cycles;
70 struct dentry *debugfs_root;
71};
72
73#define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
74#define cc_to_vclock(d) container_of((d), struct ptp_vclock, cc)
75#define dw_to_vclock(d) container_of((d), struct ptp_vclock, refresh_work)
76
77struct ptp_vclock {
78 struct ptp_clock *pclock;
79 struct ptp_clock_info info;
80 struct ptp_clock *clock;
81 struct hlist_node vclock_hash_node;
82 struct cyclecounter cc;
83 struct timecounter tc;
84 struct mutex lock; /* protects tc/cc */
85};
86
87/*
88 * The function queue_cnt() is safe for readers to call without
89 * holding q->lock. Readers use this function to verify that the queue
90 * is nonempty before proceeding with a dequeue operation. The fact
91 * that a writer might concurrently increment the tail does not
92 * matter, since the queue remains nonempty nonetheless.
93 */
94static inline int queue_cnt(const struct timestamp_event_queue *q)
95{
96 /*
97 * Paired with WRITE_ONCE() in enqueue_external_timestamp(),
98 * ptp_read(), extts_fifo_show().
99 */
100 int cnt = READ_ONCE(q->tail) - READ_ONCE(q->head);
101 return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
102}
103
104/* Check if ptp virtual clock is in use */
105static inline bool ptp_vclock_in_use(struct ptp_clock *ptp)
106{
107 bool in_use = false;
108
109 /* Virtual clocks can't be stacked on top of virtual clocks.
110 * Avoid acquiring the n_vclocks_mux on virtual clocks, to allow this
111 * function to be called from code paths where the n_vclocks_mux of the
112 * parent physical clock is already held. Functionally that's not an
113 * issue, but lockdep would complain, because they have the same lock
114 * class.
115 */
116 if (ptp->is_virtual_clock)
117 return false;
118
119 if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
120 return true;
121
122 if (ptp->n_vclocks)
123 in_use = true;
124
125 mutex_unlock(lock: &ptp->n_vclocks_mux);
126
127 return in_use;
128}
129
130/* Check if ptp clock shall be free running */
131static inline bool ptp_clock_freerun(struct ptp_clock *ptp)
132{
133 if (ptp->has_cycles)
134 return false;
135
136 return ptp_vclock_in_use(ptp);
137}
138
139extern const struct class ptp_class;
140
141/*
142 * see ptp_chardev.c
143 */
144
145void ptp_disable_all_events(struct ptp_clock *ptp);
146
147/* caller must hold pincfg_mux */
148int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
149 enum ptp_pin_function func, unsigned int chan);
150
151long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
152 unsigned long arg);
153
154int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode);
155
156int ptp_release(struct posix_clock_context *pccontext);
157
158ssize_t ptp_read(struct posix_clock_context *pccontext, uint flags, char __user *buf,
159 size_t cnt);
160
161__poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
162 poll_table *wait);
163
164/*
165 * see ptp_sysfs.c
166 */
167
168extern const struct attribute_group *ptp_groups[];
169
170int ptp_populate_pin_groups(struct ptp_clock *ptp);
171void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
172
173struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock);
174void ptp_vclock_unregister(struct ptp_vclock *vclock);
175#endif
176

source code of linux/drivers/ptp/ptp_private.h