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223 lines
5.4 KiB
223 lines
5.4 KiB
// 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 <[email protected]> |
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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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