drivers/ptp/ptp_private.h

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