// SPDX-License-Identifier: GPL-2.0-or-later/* * kernel API * * Copyright (C) 2005-2009   Rodolfo Giometti <giometti@linux.it> */ #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 * ERR_PTR(errno). */ 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 ERR_PTR(err);}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);