linux/drivers/ptp/ptp_private.h

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/*
* PTP 1588 clock support - private declarations for the core module.
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _PTP_PRIVATE_H_
#define _PTP_PRIVATE_H_
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/posix-clock.h>
#include <linux/ptp_clock.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/time.h>
#define PTP_MAX_TIMESTAMPS 128
#define PTP_BUF_TIMESTAMPS 30
struct timestamp_event_queue {
struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];
int head;
int tail;
spinlock_t lock;
};
struct ptp_clock {
struct posix_clock clock;
struct device *dev;
struct ptp_clock_info *info;
dev_t devid;
int index; /* index into clocks.map */
struct pps_device *pps_source;
struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
struct mutex tsevq_mux; /* one process at a time reading the fifo */
wait_queue_head_t tsev_wq;
int defunct; /* tells readers to go away when clock is being removed */
};
/*
* The function queue_cnt() is safe for readers to call without
* holding q->lock. Readers use this function to verify that the queue
* is nonempty before proceeding with a dequeue operation. The fact
* that a writer might concurrently increment the tail does not
* matter, since the queue remains nonempty nonetheless.
*/
static inline int queue_cnt(struct timestamp_event_queue *q)
{
int cnt = q->tail - q->head;
return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
}
/*
* see ptp_chardev.c
*/
long ptp_ioctl(struct posix_clock *pc,
unsigned int cmd, unsigned long arg);
int ptp_open(struct posix_clock *pc, fmode_t fmode);
ssize_t ptp_read(struct posix_clock *pc,
uint flags, char __user *buf, size_t cnt);
uint ptp_poll(struct posix_clock *pc,
struct file *fp, poll_table *wait);
/*
* see ptp_sysfs.c
*/
extern struct device_attribute ptp_dev_attrs[];
int ptp_cleanup_sysfs(struct ptp_clock *ptp);
int ptp_populate_sysfs(struct ptp_clock *ptp);
#endif