drivers/ptp/ptp_private.h

   1 /*
   2  * PTP 1588 clock support - private declarations for the core module.
   3  *
   4  * Copyright (C) 2010 OMICRON electronics GmbH
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #ifndef _PTP_PRIVATE_H_
  21 #define _PTP_PRIVATE_H_
  22
  23 #include <linux/cdev.h>
  24 #include <linux/device.h>
  25 #include <linux/mutex.h>
  26 #include <linux/posix-clock.h>
  27 #include <linux/ptp_clock.h>
  28 #include <linux/ptp_clock_kernel.h>
  29 #include <linux/time.h>
  30
  31 #define PTP_MAX_TIMESTAMPS 128
  32 #define PTP_BUF_TIMESTAMPS 30
  33
  34 struct timestamp_event_queue {
  35         struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
  36         int head;
  37         int tail;
  38         spinlock_t lock;
  39 };
  40
  41 struct ptp_clock {
  42         struct posix_clock clock;
  43         struct device *dev;
  44         struct ptp_clock_info *info;
  45         dev_t devid;
  46         int index; /* index into clocks.map */
  47         struct pps_device *pps_source;
  48         long dialed_frequency; /* remembers the frequency adjustment */
  49         struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
  50         struct mutex tsevq_mux; /* one process at a time reading the fifo */
  51         struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
  52         wait_queue_head_t tsev_wq;
  53         int defunct; /* tells readers to go away when clock is being removed */
  54         struct device_attribute *pin_dev_attr;
  55         struct attribute **pin_attr;
  56         struct attribute_group pin_attr_group;
  57         /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
  58         const struct attribute_group *pin_attr_groups[2];
  59 };
  60
  61 /*
  62  * The function queue_cnt() is safe for readers to call without
  63  * holding q->lock. Readers use this function to verify that the queue
  64  * is nonempty before proceeding with a dequeue operation. The fact
  65  * that a writer might concurrently increment the tail does not
  66  * matter, since the queue remains nonempty nonetheless.
  67  */
  68 static inline int queue_cnt(struct timestamp_event_queue *q)
  69 {
  70         int cnt = q->tail - q->head;
  71         return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
  72 }
  73
  74 /*
  75  * see ptp_chardev.c
  76  */
  77
  78 /* caller must hold pincfg_mux */
  79 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  80                     enum ptp_pin_function func, unsigned int chan);
  81
  82 long ptp_ioctl(struct posix_clock *pc,
  83                unsigned int cmd, unsigned long arg);
  84
  85 int ptp_open(struct posix_clock *pc, fmode_t fmode);
  86
  87 ssize_t ptp_read(struct posix_clock *pc,
  88                  uint flags, char __user *buf, size_t cnt);
  89
  90 uint ptp_poll(struct posix_clock *pc,
  91               struct file *fp, poll_table *wait);
  92
  93 /*
  94  * see ptp_sysfs.c
  95  */
  96
  97 extern const struct attribute_group *ptp_groups[];
  98
  99 int ptp_populate_pin_groups(struct ptp_clock *ptp);
 100 void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
 101
 102 #endif