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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110// SPDX-License-Identifier: GPL-2.0-or-later/* * PPS kernel consumer API * * Copyright (C) 2009-2010 Alexander Gordeev <lasaine@lvk.cs.msu.su> */
#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 */static DEFINE_SPINLOCK(pps_kc_hardpps_lock);/* PPS API (RFC 2783): current source and mode for kernel consumer */static struct pps_device *pps_kc_hardpps_dev; /* unique pointer to device */static 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);}