LXR linux/drivers/ptp/ptp

   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/kthread.h>
  26#include <linux/mutex.h>
  27#include <linux/posix-clock.h>
  28#include <linux/ptp_clock.h>
  29#include <linux/ptp_clock_kernel.h>
  30#include <linux/time.h>
  31
  32#define PTP_MAX_TIMESTAMPS 128
  33#define PTP_BUF_TIMESTAMPS 30
  34
  35struct timestamp_event_queue {
  36        struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
  37        int head;
  38        int tail;
  39        spinlock_t lock;
  40};
  41
  42struct ptp_clock {
  43        struct posix_clock clock;
  44        struct device *dev;
  45        struct ptp_clock_info *info;
  46        dev_t devid;
  47        int index; /* index into clocks.map */
  48        struct pps_device *pps_source;
  49        long dialed_frequency; /* remembers the frequency adjustment */
  50        struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
  51        struct mutex tsevq_mux; /* one process at a time reading the fifo */
  52        struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
  53        wait_queue_head_t tsev_wq;
  54        int defunct; /* tells readers to go away when clock is being removed */
  55        struct device_attribute *pin_dev_attr;
  56        struct attribute **pin_attr;
  57        struct attribute_group pin_attr_group;
  58        /* 1st entry is a pointer to the real group, 2nd is NULL terminator */
  59        const struct attribute_group *pin_attr_groups[2];
  60        struct kthread_worker *kworker;
  61        struct kthread_delayed_work aux_work;
  62};
  63
  64/*
  65 * The function queue_cnt() is safe for readers to call without
  66 * holding q->lock. Readers use this function to verify that the queue
  67 * is nonempty before proceeding with a dequeue operation. The fact
  68 * that a writer might concurrently increment the tail does not
  69 * matter, since the queue remains nonempty nonetheless.
  70 */
  71static inline int queue_cnt(struct timestamp_event_queue *q)
  72{
  73        int cnt = q->tail - q->head;
  74        return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
  75}
  76
  77/*
  78 * see ptp_chardev.c
  79 */
  80
  81/* caller must hold pincfg_mux */
  82int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  83                    enum ptp_pin_function func, unsigned int chan);
  84
  85long ptp_ioctl(struct posix_clock *pc,
  86               unsigned int cmd, unsigned long arg);
  87
  88int ptp_open(struct posix_clock *pc, fmode_t fmode);
  89
  90ssize_t ptp_read(struct posix_clock *pc,
  91                 uint flags, char __user *buf, size_t cnt);
  92
  93__poll_t ptp_poll(struct posix_clock *pc,
  94              struct file *fp, poll_table *wait);
  95
  96/*
  97 * see ptp_sysfs.c
  98 */
  99
 100extern const struct attribute_group *ptp_groups[];
 101
 102int ptp_populate_pin_groups(struct ptp_clock *ptp);
 103void ptp_cleanup_pin_groups(struct ptp_clock *ptp);
 104
 105#endif
 106