drivers/ptp/ptp_private.h

0001 /* SPDX-License-Identifier: GPL-2.0-or-later */
0002 /*
0003  * PTP 1588 clock support - private declarations for the core module.
0004  *
0005  * Copyright (C) 2010 OMICRON electronics GmbH
0006  */
0007 #ifndef _PTP_PRIVATE_H_
0008 #define _PTP_PRIVATE_H_
0009
0010 #include <linux/cdev.h>
0011 #include <linux/device.h>
0012 #include <linux/kthread.h>
0013 #include <linux/mutex.h>
0014 #include <linux/posix-clock.h>
0015 #include <linux/ptp_clock.h>
0016 #include <linux/ptp_clock_kernel.h>
0017 #include <linux/time.h>
0018
0019 #define PTP_MAX_TIMESTAMPS 128
0020 #define PTP_BUF_TIMESTAMPS 30
0021 #define PTP_DEFAULT_MAX_VCLOCKS 20
0022
0023 struct timestamp_event_queue {
0024     struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
0025     int head;
0026     int tail;
0027     spinlock_t lock;
0028 };
0029
0030 struct ptp_clock {
0031     struct posix_clock clock;
0032     struct device dev;
0033     struct ptp_clock_info *info;
0034     dev_t devid;
0035     int index; /* index into clocks.map */
0036     struct pps_device *pps_source;
0037     long dialed_frequency; /* remembers the frequency adjustment */
0038     struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
0039     struct mutex tsevq_mux; /* one process at a time reading the fifo */
0040     struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
0041     wait_queue_head_t tsev_wq;
0042     int defunct; /* tells readers to go away when clock is being removed */
0043     struct device_attribute *pin_dev_attr;
0044     struct attribute **pin_attr;
0045     struct attribute_group pin_attr_group;
0046     /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
0047     const struct attribute_group *pin_attr_groups[2];
0048     struct kthread_worker *kworker;
0049     struct kthread_delayed_work aux_work;
0050     unsigned int max_vclocks;
0051     unsigned int n_vclocks;
0052     int *vclock_index;
0053     struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
0054     bool is_virtual_clock;
0055     bool has_cycles;
0056 };
0057
0058 #define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
0059 #define cc_to_vclock(d) container_of((d), struct ptp_vclock, cc)
0060 #define dw_to_vclock(d) container_of((d), struct ptp_vclock, refresh_work)
0061
0062 struct ptp_vclock {
0063     struct ptp_clock *pclock;
0064     struct ptp_clock_info info;
0065     struct ptp_clock *clock;
0066     struct hlist_node vclock_hash_node;
0067     struct cyclecounter cc;
0068     struct timecounter tc;
0069     spinlock_t lock;    /* protects tc/cc */
0070 };
0071
0072 /*
0073  * The function queue_cnt() is safe for readers to call without
0074  * holding q->lock. Readers use this function to verify that the queue
0075  * is nonempty before proceeding with a dequeue operation. The fact
0076  * that a writer might concurrently increment the tail does not
0077  * matter, since the queue remains nonempty nonetheless.
0078  */
0079 static inline int queue_cnt(struct timestamp_event_queue *q)
0080 {
0081     int cnt = q->tail - q->head;
0082     return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
0083 }
0084
0085 /* Check if ptp virtual clock is in use */
0086 static inline bool ptp_vclock_in_use(struct ptp_clock *ptp)
0087 {
0088     bool in_use = false;
0089
0090     if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
0091         return true;
0092
0093     if (!ptp->is_virtual_clock && ptp->n_vclocks)
0094         in_use = true;
0095
0096     mutex_unlock(&ptp->n_vclocks_mux);
0097
0098     return in_use;
0099 }
0100
0101 /* Check if ptp clock shall be free running */
0102 static inline bool ptp_clock_freerun(struct ptp_clock *ptp)
0103 {
0104     if (ptp->has_cycles)
0105         return false;
0106
0107     return ptp_vclock_in_use(ptp);
0108 }
0109
0110 extern struct class *ptp_class;
0111
0112 /*
0113  * see ptp_chardev.c
0114  */
0115
0116 /* caller must hold pincfg_mux */
0117 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
0118             enum ptp_pin_function func, unsigned int chan);
0119
0120 long ptp_ioctl(struct posix_clock *pc,
0121            unsigned int cmd, unsigned long arg);
0122
0123 int ptp_open(struct posix_clock *pc, fmode_t fmode);
0124
0125 ssize_t ptp_read(struct posix_clock *pc,
0126          uint flags, char __user *buf, size_t cnt);
0127
0128 __poll_t ptp_poll(struct posix_clock *pc,
0129           struct file *fp, poll_table *wait);
0130
0131 /*
0132  * see ptp_sysfs.c
0133  */
0134
0135 extern const struct attribute_group *ptp_groups[];
0136
0137 int ptp_populate_pin_groups(struct ptp_clock *ptp);
0138 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
0139
0140 struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock);
0141 void ptp_vclock_unregister(struct ptp_vclock *vclock);
0142 #endif