mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 05:11:48 +00:00
d94ba80ebb
This patch adds an infrastructure for hardware clocks that implement IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a registration method to particular hardware clock drivers. Each clock is presented as a standard POSIX clock. The ancillary clock features are exposed in two different ways, via the sysfs and by a character device. Signed-off-by: Richard Cochran <richard.cochran@omicron.at> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: John Stultz <john.stultz@linaro.org>
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/*
|
|
* 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
|