Commit 717c0336 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Linus Torvalds

pps: add kernel consumer support

Add an optional feature of PPSAPI, kernel consumer support, which uses the
added hardpps() function.
Signed-off-by: default avatarAlexander Gordeev <lasaine@lvk.cs.msu.su>
Acked-by: default avatarRodolfo Giometti <giometti@linux.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e2c18e49
......@@ -247,7 +247,7 @@ Code Seq#(hex) Include File Comments
'p' 40-7F linux/nvram.h
'p' 80-9F linux/ppdev.h user-space parport
<mailto:tim@cyberelk.net>
'p' A1-A4 linux/pps.h LinuxPPS
'p' A1-A5 linux/pps.h LinuxPPS
<mailto:giometti@linux.it>
'q' 00-1F linux/serio.h
'q' 80-FF linux/telephony.h Internet PhoneJACK, Internet LineJACK
......
......@@ -3,6 +3,7 @@
#
pps_core-y := pps.o kapi.o sysfs.o
pps_core-$(CONFIG_NTP_PPS) += kc.o
obj-$(CONFIG_PPS) := pps_core.o
obj-y += clients/
......
......@@ -26,11 +26,14 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/pps_kernel.h>
#include <linux/slab.h>
#include "kc.h"
/*
* Local functions
*/
......@@ -139,6 +142,7 @@ EXPORT_SYMBOL(pps_register_source);
void pps_unregister_source(struct pps_device *pps)
{
pps_kc_remove(pps);
pps_unregister_cdev(pps);
/* don't have to kfree(pps) here because it will be done on
......@@ -211,6 +215,8 @@ void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
captured = ~0;
}
pps_kc_event(pps, ts, event);
/* Wake up if captured something */
if (captured) {
pps->last_ev++;
......
/*
* PPS kernel consumer API
*
* Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su>
*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/pps_kernel.h>
#include "kc.h"
/*
* Global variables
*/
/* state variables to bind kernel consumer */
DEFINE_SPINLOCK(pps_kc_hardpps_lock);
/* PPS API (RFC 2783): current source and mode for kernel consumer */
struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */
int pps_kc_hardpps_mode; /* mode bits for kernel consumer */
/* pps_kc_bind - control PPS kernel consumer binding
* @pps: the PPS source
* @bind_args: kernel consumer bind parameters
*
* This function is used to bind or unbind PPS kernel consumer according to
* supplied parameters. Should not be called in interrupt context.
*/
int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args)
{
/* Check if another consumer is already bound */
spin_lock_irq(&pps_kc_hardpps_lock);
if (bind_args->edge == 0)
if (pps_kc_hardpps_dev == pps) {
pps_kc_hardpps_mode = 0;
pps_kc_hardpps_dev = NULL;
spin_unlock_irq(&pps_kc_hardpps_lock);
dev_info(pps->dev, "unbound kernel"
" consumer\n");
} else {
spin_unlock_irq(&pps_kc_hardpps_lock);
dev_err(pps->dev, "selected kernel consumer"
" is not bound\n");
return -EINVAL;
}
else
if (pps_kc_hardpps_dev == NULL ||
pps_kc_hardpps_dev == pps) {
pps_kc_hardpps_mode = bind_args->edge;
pps_kc_hardpps_dev = pps;
spin_unlock_irq(&pps_kc_hardpps_lock);
dev_info(pps->dev, "bound kernel consumer: "
"edge=0x%x\n", bind_args->edge);
} else {
spin_unlock_irq(&pps_kc_hardpps_lock);
dev_err(pps->dev, "another kernel consumer"
" is already bound\n");
return -EINVAL;
}
return 0;
}
/* pps_kc_remove - unbind kernel consumer on PPS source removal
* @pps: the PPS source
*
* This function is used to disable kernel consumer on PPS source removal
* if this source was bound to PPS kernel consumer. Can be called on any
* source safely. Should not be called in interrupt context.
*/
void pps_kc_remove(struct pps_device *pps)
{
spin_lock_irq(&pps_kc_hardpps_lock);
if (pps == pps_kc_hardpps_dev) {
pps_kc_hardpps_mode = 0;
pps_kc_hardpps_dev = NULL;
spin_unlock_irq(&pps_kc_hardpps_lock);
dev_info(pps->dev, "unbound kernel consumer"
" on device removal\n");
} else
spin_unlock_irq(&pps_kc_hardpps_lock);
}
/* pps_kc_event - call hardpps() on PPS event
* @pps: the PPS source
* @ts: PPS event timestamp
* @event: PPS event edge
*
* This function calls hardpps() when an event from bound PPS source occurs.
*/
void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts,
int event)
{
unsigned long flags;
/* Pass some events to kernel consumer if activated */
spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
hardpps(&ts->ts_real, &ts->ts_raw);
spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
}
/*
* PPS kernel consumer API header
*
* Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su>
*
* 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 LINUX_PPS_KC_H
#define LINUX_PPS_KC_H
#include <linux/errno.h>
#include <linux/pps_kernel.h>
#ifdef CONFIG_NTP_PPS
extern int pps_kc_bind(struct pps_device *pps,
struct pps_bind_args *bind_args);
extern void pps_kc_remove(struct pps_device *pps);
extern void pps_kc_event(struct pps_device *pps,
struct pps_event_time *ts, int event);
#else /* CONFIG_NTP_PPS */
static inline int pps_kc_bind(struct pps_device *pps,
struct pps_bind_args *bind_args) { return -EOPNOTSUPP; }
static inline void pps_kc_remove(struct pps_device *pps) {}
static inline void pps_kc_event(struct pps_device *pps,
struct pps_event_time *ts, int event) {}
#endif /* CONFIG_NTP_PPS */
#endif /* LINUX_PPS_KC_H */
......@@ -33,6 +33,8 @@
#include <linux/pps_kernel.h>
#include <linux/slab.h>
#include "kc.h"
/*
* Local variables
*/
......@@ -198,9 +200,43 @@ static long pps_cdev_ioctl(struct file *file,
break;
}
case PPS_KC_BIND: {
struct pps_bind_args bind_args;
dev_dbg(pps->dev, "PPS_KC_BIND\n");
/* Check the capabilities */
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (copy_from_user(&bind_args, uarg,
sizeof(struct pps_bind_args)))
return -EFAULT;
/* Check for supported capabilities */
if ((bind_args.edge & ~pps->info.mode) != 0) {
dev_err(pps->dev, "unsupported capabilities (%x)\n",
bind_args.edge);
return -EINVAL;
}
/* Validate parameters roughly */
if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
(bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
bind_args.consumer != PPS_KC_HARDPPS) {
dev_err(pps->dev, "invalid kernel consumer bind"
" parameters (%x)\n", bind_args.edge);
return -EINVAL;
}
err = pps_kc_bind(pps, &bind_args);
if (err < 0)
return err;
break;
}
default:
return -ENOTTY;
break;
}
return 0;
......
......@@ -114,11 +114,18 @@ struct pps_fdata {
struct pps_ktime timeout;
};
struct pps_bind_args {
int tsformat; /* format of time stamps */
int edge; /* selected event type */
int consumer; /* selected kernel consumer */
};
#include <linux/ioctl.h>
#define PPS_GETPARAMS _IOR('p', 0xa1, struct pps_kparams *)
#define PPS_SETPARAMS _IOW('p', 0xa2, struct pps_kparams *)
#define PPS_GETCAP _IOR('p', 0xa3, int *)
#define PPS_FETCH _IOWR('p', 0xa4, struct pps_fdata *)
#define PPS_KC_BIND _IOW('p', 0xa5, struct pps_bind_args *)
#endif /* _PPS_H_ */
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