kernel-ark/drivers/pps/kapi.c
Arnd Bergmann ade1bdffe9 ntp/pps: use y2038 safe types in pps_event_time
The pps_event_time uses two 'timespec' structures internally, which
suffer from the y2038 problem. The uses of this structure are
fairly self-contained in the pps code, so this replaces them all at
once.

Unfortunately, this includes the sfc ethernet driver aside from the
pps subsystem, so we change that one as well. Both touch the
same data structure, and there probably is no good way to split
the patch into smaller units.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-10-01 09:59:16 -07:00

237 lines
6.0 KiB
C

/*
* kernel API
*
*
* Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
*
* 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/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
*/
static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
{
ts->nsec += offset->nsec;
while (ts->nsec >= NSEC_PER_SEC) {
ts->nsec -= NSEC_PER_SEC;
ts->sec++;
}
while (ts->nsec < 0) {
ts->nsec += NSEC_PER_SEC;
ts->sec--;
}
ts->sec += offset->sec;
}
static void pps_echo_client_default(struct pps_device *pps, int event,
void *data)
{
dev_info(pps->dev, "echo %s %s\n",
event & PPS_CAPTUREASSERT ? "assert" : "",
event & PPS_CAPTURECLEAR ? "clear" : "");
}
/*
* Exported functions
*/
/* pps_register_source - add a PPS source in the system
* @info: the PPS info struct
* @default_params: the default PPS parameters of the new source
*
* This function is used to add a new PPS source in the system. The new
* source is described by info's fields and it will have, as default PPS
* parameters, the ones specified into default_params.
*
* The function returns, in case of success, the PPS device. Otherwise NULL.
*/
struct pps_device *pps_register_source(struct pps_source_info *info,
int default_params)
{
struct pps_device *pps;
int err;
/* Sanity checks */
if ((info->mode & default_params) != default_params) {
pr_err("%s: unsupported default parameters\n",
info->name);
err = -EINVAL;
goto pps_register_source_exit;
}
if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
pr_err("%s: unspecified time format\n",
info->name);
err = -EINVAL;
goto pps_register_source_exit;
}
/* Allocate memory for the new PPS source struct */
pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
if (pps == NULL) {
err = -ENOMEM;
goto pps_register_source_exit;
}
/* These initializations must be done before calling idr_alloc()
* in order to avoid reces into pps_event().
*/
pps->params.api_version = PPS_API_VERS;
pps->params.mode = default_params;
pps->info = *info;
/* check for default echo function */
if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) &&
pps->info.echo == NULL)
pps->info.echo = pps_echo_client_default;
init_waitqueue_head(&pps->queue);
spin_lock_init(&pps->lock);
/* Create the char device */
err = pps_register_cdev(pps);
if (err < 0) {
pr_err("%s: unable to create char device\n",
info->name);
goto kfree_pps;
}
dev_info(pps->dev, "new PPS source %s\n", info->name);
return pps;
kfree_pps:
kfree(pps);
pps_register_source_exit:
pr_err("%s: unable to register source\n", info->name);
return NULL;
}
EXPORT_SYMBOL(pps_register_source);
/* pps_unregister_source - remove a PPS source from the system
* @pps: the PPS source
*
* This function is used to remove a previously registered PPS source from
* the system.
*/
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
* device destruction */
}
EXPORT_SYMBOL(pps_unregister_source);
/* pps_event - register a PPS event into the system
* @pps: the PPS device
* @ts: the event timestamp
* @event: the event type
* @data: userdef pointer
*
* This function is used by each PPS client in order to register a new
* PPS event into the system (it's usually called inside an IRQ handler).
*
* If an echo function is associated with the PPS device it will be called
* as:
* pps->info.echo(pps, event, data);
*/
void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
void *data)
{
unsigned long flags;
int captured = 0;
struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 };
/* check event type */
BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0);
dev_dbg(pps->dev, "PPS event at %lld.%09ld\n",
(s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec);
timespec_to_pps_ktime(&ts_real, ts->ts_real);
spin_lock_irqsave(&pps->lock, flags);
/* Must call the echo function? */
if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
pps->info.echo(pps, event, data);
/* Check the event */
pps->current_mode = pps->params.mode;
if (event & pps->params.mode & PPS_CAPTUREASSERT) {
/* We have to add an offset? */
if (pps->params.mode & PPS_OFFSETASSERT)
pps_add_offset(&ts_real,
&pps->params.assert_off_tu);
/* Save the time stamp */
pps->assert_tu = ts_real;
pps->assert_sequence++;
dev_dbg(pps->dev, "capture assert seq #%u\n",
pps->assert_sequence);
captured = ~0;
}
if (event & pps->params.mode & PPS_CAPTURECLEAR) {
/* We have to add an offset? */
if (pps->params.mode & PPS_OFFSETCLEAR)
pps_add_offset(&ts_real,
&pps->params.clear_off_tu);
/* Save the time stamp */
pps->clear_tu = ts_real;
pps->clear_sequence++;
dev_dbg(pps->dev, "capture clear seq #%u\n",
pps->clear_sequence);
captured = ~0;
}
pps_kc_event(pps, ts, event);
/* Wake up if captured something */
if (captured) {
pps->last_ev++;
wake_up_interruptible_all(&pps->queue);
kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
}
spin_unlock_irqrestore(&pps->lock, flags);
}
EXPORT_SYMBOL(pps_event);