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 */ 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 */ 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 */ 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