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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220// 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_obj(struct pps_device); 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 pps_register_source_exit; }
dev_dbg(&pps->dev, "new PPS source %s\n", info->name);
return 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 %ptSp\n", &ts->ts_real);
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);