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