forked from mirrors/linux
513b032c98
The PPS serial line discipline wants to attach a PPS device to a tty without changing the tty code to add a struct pps_device * pointer. Since the number of PPS devices in a typical system is generally very low (n=1 is by far the most common), it's practical to search the entire list of allocated pps devices. (We capture the timestamp before the lookup, so the timing isn't affected.) It is a bit ugly that this function, which is part of the in-kernel PPS API, has to be in pps.c as opposed to kapi,c, but that's not something that affects users. Signed-off-by: George Spelvin <linux@horizon.com> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
140 lines
3.6 KiB
C
140 lines
3.6 KiB
C
/*
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* PPS API kernel header
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*
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* Copyright (C) 2009 Rodolfo Giometti <giometti@linux.it>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef LINUX_PPS_KERNEL_H
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#define LINUX_PPS_KERNEL_H
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#include <linux/pps.h>
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#include <linux/cdev.h>
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#include <linux/device.h>
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#include <linux/time.h>
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/*
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* Global defines
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*/
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struct pps_device;
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/* The specific PPS source info */
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struct pps_source_info {
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char name[PPS_MAX_NAME_LEN]; /* simbolic name */
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char path[PPS_MAX_NAME_LEN]; /* path of connected device */
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int mode; /* PPS's allowed mode */
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void (*echo)(struct pps_device *pps,
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int event, void *data); /* PPS echo function */
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struct module *owner;
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struct device *dev; /* Parent device for device_create */
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};
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struct pps_event_time {
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#ifdef CONFIG_NTP_PPS
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struct timespec ts_raw;
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#endif /* CONFIG_NTP_PPS */
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struct timespec ts_real;
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};
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/* The main struct */
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struct pps_device {
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struct pps_source_info info; /* PSS source info */
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struct pps_kparams params; /* PPS's current params */
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__u32 assert_sequence; /* PPS' assert event seq # */
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__u32 clear_sequence; /* PPS' clear event seq # */
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struct pps_ktime assert_tu;
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struct pps_ktime clear_tu;
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int current_mode; /* PPS mode at event time */
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unsigned int last_ev; /* last PPS event id */
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wait_queue_head_t queue; /* PPS event queue */
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unsigned int id; /* PPS source unique ID */
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void const *lookup_cookie; /* pps_lookup_dev only */
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struct cdev cdev;
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struct device *dev;
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struct fasync_struct *async_queue; /* fasync method */
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spinlock_t lock;
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};
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/*
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* Global variables
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*/
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extern struct device_attribute pps_attrs[];
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/*
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* Internal functions.
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*
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* These are not actually part of the exported API, but this is a
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* convenient header file to put them in.
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*/
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extern int pps_register_cdev(struct pps_device *pps);
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extern void pps_unregister_cdev(struct pps_device *pps);
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/*
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* Exported functions
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*/
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extern struct pps_device *pps_register_source(
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struct pps_source_info *info, int default_params);
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extern void pps_unregister_source(struct pps_device *pps);
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extern void pps_event(struct pps_device *pps,
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struct pps_event_time *ts, int event, void *data);
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/* Look up a pps device by magic cookie */
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struct pps_device *pps_lookup_dev(void const *cookie);
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static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
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struct timespec ts)
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{
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kt->sec = ts.tv_sec;
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kt->nsec = ts.tv_nsec;
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}
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#ifdef CONFIG_NTP_PPS
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static inline void pps_get_ts(struct pps_event_time *ts)
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{
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getnstime_raw_and_real(&ts->ts_raw, &ts->ts_real);
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}
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#else /* CONFIG_NTP_PPS */
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static inline void pps_get_ts(struct pps_event_time *ts)
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{
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getnstimeofday(&ts->ts_real);
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}
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#endif /* CONFIG_NTP_PPS */
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/* Subtract known time delay from PPS event time(s) */
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static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
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{
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ts->ts_real = timespec_sub(ts->ts_real, delta);
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#ifdef CONFIG_NTP_PPS
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ts->ts_raw = timespec_sub(ts->ts_raw, delta);
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#endif
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}
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#endif /* LINUX_PPS_KERNEL_H */
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