--- /dev/null
+/*
+ * kernel API
+ *
+ *
+ * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
+ *
+ * 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.
+ */
+
+#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 NULL.
+ */
+
+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 NULL;
+}
+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 %ld.%09ld\n",
+ 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);
Code Review / kvmfornfv.git / blobdiff