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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 441 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
223 lines
5.4 KiB
C
223 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* kernel API
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*
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* Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/time.h>
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#include <linux/timex.h>
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#include <linux/spinlock.h>
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#include <linux/fs.h>
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#include <linux/pps_kernel.h>
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#include <linux/slab.h>
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#include "kc.h"
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/*
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* Local functions
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*/
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static void pps_add_offset(struct pps_ktime *ts, struct pps_ktime *offset)
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{
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ts->nsec += offset->nsec;
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while (ts->nsec >= NSEC_PER_SEC) {
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ts->nsec -= NSEC_PER_SEC;
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ts->sec++;
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}
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while (ts->nsec < 0) {
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ts->nsec += NSEC_PER_SEC;
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ts->sec--;
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}
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ts->sec += offset->sec;
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}
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static void pps_echo_client_default(struct pps_device *pps, int event,
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void *data)
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{
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dev_info(pps->dev, "echo %s %s\n",
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event & PPS_CAPTUREASSERT ? "assert" : "",
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event & PPS_CAPTURECLEAR ? "clear" : "");
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}
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/*
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* Exported functions
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*/
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/* pps_register_source - add a PPS source in the system
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* @info: the PPS info struct
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* @default_params: the default PPS parameters of the new source
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*
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* This function is used to add a new PPS source in the system. The new
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* source is described by info's fields and it will have, as default PPS
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* parameters, the ones specified into default_params.
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*
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* The function returns, in case of success, the PPS device. Otherwise
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* ERR_PTR(errno).
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*/
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struct pps_device *pps_register_source(struct pps_source_info *info,
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int default_params)
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{
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struct pps_device *pps;
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int err;
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/* Sanity checks */
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if ((info->mode & default_params) != default_params) {
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pr_err("%s: unsupported default parameters\n",
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info->name);
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err = -EINVAL;
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goto pps_register_source_exit;
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}
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if ((info->mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
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pr_err("%s: unspecified time format\n",
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info->name);
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err = -EINVAL;
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goto pps_register_source_exit;
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}
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/* Allocate memory for the new PPS source struct */
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pps = kzalloc(sizeof(struct pps_device), GFP_KERNEL);
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if (pps == NULL) {
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err = -ENOMEM;
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goto pps_register_source_exit;
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}
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/* These initializations must be done before calling idr_alloc()
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* in order to avoid reces into pps_event().
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*/
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pps->params.api_version = PPS_API_VERS;
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pps->params.mode = default_params;
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pps->info = *info;
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/* check for default echo function */
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if ((pps->info.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) &&
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pps->info.echo == NULL)
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pps->info.echo = pps_echo_client_default;
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init_waitqueue_head(&pps->queue);
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spin_lock_init(&pps->lock);
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/* Create the char device */
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err = pps_register_cdev(pps);
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if (err < 0) {
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pr_err("%s: unable to create char device\n",
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info->name);
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goto kfree_pps;
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}
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dev_info(pps->dev, "new PPS source %s\n", info->name);
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return pps;
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kfree_pps:
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kfree(pps);
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pps_register_source_exit:
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pr_err("%s: unable to register source\n", info->name);
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return ERR_PTR(err);
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}
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EXPORT_SYMBOL(pps_register_source);
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/* pps_unregister_source - remove a PPS source from the system
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* @pps: the PPS source
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*
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* This function is used to remove a previously registered PPS source from
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* the system.
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*/
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void pps_unregister_source(struct pps_device *pps)
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{
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pps_kc_remove(pps);
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pps_unregister_cdev(pps);
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/* don't have to kfree(pps) here because it will be done on
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* device destruction */
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}
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EXPORT_SYMBOL(pps_unregister_source);
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/* pps_event - register a PPS event into the system
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* @pps: the PPS device
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* @ts: the event timestamp
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* @event: the event type
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* @data: userdef pointer
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*
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* This function is used by each PPS client in order to register a new
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* PPS event into the system (it's usually called inside an IRQ handler).
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*
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* If an echo function is associated with the PPS device it will be called
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* as:
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* pps->info.echo(pps, event, data);
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*/
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void pps_event(struct pps_device *pps, struct pps_event_time *ts, int event,
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void *data)
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{
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unsigned long flags;
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int captured = 0;
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struct pps_ktime ts_real = { .sec = 0, .nsec = 0, .flags = 0 };
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/* check event type */
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BUG_ON((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0);
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dev_dbg(pps->dev, "PPS event at %lld.%09ld\n",
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(s64)ts->ts_real.tv_sec, ts->ts_real.tv_nsec);
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timespec_to_pps_ktime(&ts_real, ts->ts_real);
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spin_lock_irqsave(&pps->lock, flags);
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/* Must call the echo function? */
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if ((pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)))
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pps->info.echo(pps, event, data);
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/* Check the event */
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pps->current_mode = pps->params.mode;
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if (event & pps->params.mode & PPS_CAPTUREASSERT) {
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/* We have to add an offset? */
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if (pps->params.mode & PPS_OFFSETASSERT)
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pps_add_offset(&ts_real,
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&pps->params.assert_off_tu);
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/* Save the time stamp */
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pps->assert_tu = ts_real;
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pps->assert_sequence++;
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dev_dbg(pps->dev, "capture assert seq #%u\n",
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pps->assert_sequence);
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captured = ~0;
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}
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if (event & pps->params.mode & PPS_CAPTURECLEAR) {
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/* We have to add an offset? */
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if (pps->params.mode & PPS_OFFSETCLEAR)
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pps_add_offset(&ts_real,
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&pps->params.clear_off_tu);
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/* Save the time stamp */
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pps->clear_tu = ts_real;
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pps->clear_sequence++;
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dev_dbg(pps->dev, "capture clear seq #%u\n",
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pps->clear_sequence);
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captured = ~0;
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}
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pps_kc_event(pps, ts, event);
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/* Wake up if captured something */
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if (captured) {
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pps->last_ev++;
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wake_up_interruptible_all(&pps->queue);
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kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
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}
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spin_unlock_irqrestore(&pps->lock, flags);
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}
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EXPORT_SYMBOL(pps_event);
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