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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>
110 lines
3.1 KiB
C
110 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* PPS kernel consumer API
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*
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* Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su>
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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/device.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/pps_kernel.h>
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#include "kc.h"
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/*
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* Global variables
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*/
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/* state variables to bind kernel consumer */
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static DEFINE_SPINLOCK(pps_kc_hardpps_lock);
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/* PPS API (RFC 2783): current source and mode for kernel consumer */
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static struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */
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static int pps_kc_hardpps_mode; /* mode bits for kernel consumer */
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/* pps_kc_bind - control PPS kernel consumer binding
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* @pps: the PPS source
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* @bind_args: kernel consumer bind parameters
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*
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* This function is used to bind or unbind PPS kernel consumer according to
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* supplied parameters. Should not be called in interrupt context.
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*/
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int pps_kc_bind(struct pps_device *pps, struct pps_bind_args *bind_args)
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{
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/* Check if another consumer is already bound */
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spin_lock_irq(&pps_kc_hardpps_lock);
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if (bind_args->edge == 0)
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if (pps_kc_hardpps_dev == pps) {
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pps_kc_hardpps_mode = 0;
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pps_kc_hardpps_dev = NULL;
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spin_unlock_irq(&pps_kc_hardpps_lock);
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dev_info(pps->dev, "unbound kernel"
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" consumer\n");
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} else {
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spin_unlock_irq(&pps_kc_hardpps_lock);
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dev_err(pps->dev, "selected kernel consumer"
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" is not bound\n");
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return -EINVAL;
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}
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else
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if (pps_kc_hardpps_dev == NULL ||
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pps_kc_hardpps_dev == pps) {
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pps_kc_hardpps_mode = bind_args->edge;
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pps_kc_hardpps_dev = pps;
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spin_unlock_irq(&pps_kc_hardpps_lock);
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dev_info(pps->dev, "bound kernel consumer: "
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"edge=0x%x\n", bind_args->edge);
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} else {
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spin_unlock_irq(&pps_kc_hardpps_lock);
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dev_err(pps->dev, "another kernel consumer"
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" is already bound\n");
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return -EINVAL;
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}
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return 0;
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}
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/* pps_kc_remove - unbind kernel consumer on PPS source removal
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* @pps: the PPS source
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*
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* This function is used to disable kernel consumer on PPS source removal
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* if this source was bound to PPS kernel consumer. Can be called on any
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* source safely. Should not be called in interrupt context.
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*/
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void pps_kc_remove(struct pps_device *pps)
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{
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spin_lock_irq(&pps_kc_hardpps_lock);
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if (pps == pps_kc_hardpps_dev) {
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pps_kc_hardpps_mode = 0;
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pps_kc_hardpps_dev = NULL;
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spin_unlock_irq(&pps_kc_hardpps_lock);
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dev_info(pps->dev, "unbound kernel consumer"
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" on device removal\n");
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} else
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spin_unlock_irq(&pps_kc_hardpps_lock);
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}
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/* pps_kc_event - call hardpps() on PPS event
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* @pps: the PPS source
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* @ts: PPS event timestamp
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* @event: PPS event edge
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*
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* This function calls hardpps() when an event from bound PPS source occurs.
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*/
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void pps_kc_event(struct pps_device *pps, struct pps_event_time *ts,
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int event)
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{
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unsigned long flags;
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/* Pass some events to kernel consumer if activated */
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spin_lock_irqsave(&pps_kc_hardpps_lock, flags);
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if (pps == pps_kc_hardpps_dev && event & pps_kc_hardpps_mode)
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hardpps(&ts->ts_real, &ts->ts_raw);
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spin_unlock_irqrestore(&pps_kc_hardpps_lock, flags);
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}
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