From d94ba80ebbea17f036cecb104398fbcd788aa742 Mon Sep 17 00:00:00 2001 From: Richard Cochran Date: Fri, 22 Apr 2011 12:03:08 +0200 Subject: ptp: Added a brand new class driver for ptp clocks. 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 Acked-by: Arnd Bergmann Acked-by: David S. Miller Signed-off-by: John Stultz --- drivers/ptp/ptp_private.h | 92 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 drivers/ptp/ptp_private.h (limited to 'drivers/ptp/ptp_private.h') diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h new file mode 100644 index 000000000000..4d5b5082c3b1 --- /dev/null +++ b/drivers/ptp/ptp_private.h @@ -0,0 +1,92 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include + +#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 -- cgit v1.2.3