--- /dev/null
+/*
+ * v4l2-event.c
+ *
+ * V4L2 events.
+ *
+ * Copyright (C) 2009--2010 Nokia Corporation.
+ *
+ * Contact: Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-event.h>
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx)
+{
+ idx += sev->first;
+ return idx >= sev->elems ? idx - sev->elems : idx;
+}
+
+static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event)
+{
+ struct v4l2_kevent *kev;
+ unsigned long flags;
+
+ spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+
+ if (list_empty(&fh->available)) {
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+ return -ENOENT;
+ }
+
+ WARN_ON(fh->navailable == 0);
+
+ kev = list_first_entry(&fh->available, struct v4l2_kevent, list);
+ list_del(&kev->list);
+ fh->navailable--;
+
+ kev->event.pending = fh->navailable;
+ *event = kev->event;
+ kev->sev->first = sev_pos(kev->sev, 1);
+ kev->sev->in_use--;
+
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+ return 0;
+}
+
+int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
+ int nonblocking)
+{
+ int ret;
+
+ if (nonblocking)
+ return __v4l2_event_dequeue(fh, event);
+
+ /* Release the vdev lock while waiting */
+ if (fh->vdev->lock)
+ mutex_unlock(fh->vdev->lock);
+
+ do {
+ ret = wait_event_interruptible(fh->wait,
+ fh->navailable != 0);
+ if (ret < 0)
+ break;
+
+ ret = __v4l2_event_dequeue(fh, event);
+ } while (ret == -ENOENT);
+
+ if (fh->vdev->lock)
+ mutex_lock(fh->vdev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_dequeue);
+
+/* Caller must hold fh->vdev->fh_lock! */
+static struct v4l2_subscribed_event *v4l2_event_subscribed(
+ struct v4l2_fh *fh, u32 type, u32 id)
+{
+ struct v4l2_subscribed_event *sev;
+
+ assert_spin_locked(&fh->vdev->fh_lock);
+
+ list_for_each_entry(sev, &fh->subscribed, list)
+ if (sev->type == type && sev->id == id)
+ return sev;
+
+ return NULL;
+}
+
+static void __v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev,
+ const struct timespec *ts)
+{
+ struct v4l2_subscribed_event *sev;
+ struct v4l2_kevent *kev;
+ bool copy_payload = true;
+
+ /* Are we subscribed? */
+ sev = v4l2_event_subscribed(fh, ev->type, ev->id);
+ if (sev == NULL)
+ return;
+
+ /*
+ * If the event has been added to the fh->subscribed list, but its
+ * add op has not completed yet elems will be 0, treat this as
+ * not being subscribed.
+ */
+ if (!sev->elems)
+ return;
+
+ /* Increase event sequence number on fh. */
+ fh->sequence++;
+
+ /* Do we have any free events? */
+ if (sev->in_use == sev->elems) {
+ /* no, remove the oldest one */
+ kev = sev->events + sev_pos(sev, 0);
+ list_del(&kev->list);
+ sev->in_use--;
+ sev->first = sev_pos(sev, 1);
+ fh->navailable--;
+ if (sev->elems == 1) {
+ if (sev->ops && sev->ops->replace) {
+ sev->ops->replace(&kev->event, ev);
+ copy_payload = false;
+ }
+ } else if (sev->ops && sev->ops->merge) {
+ struct v4l2_kevent *second_oldest =
+ sev->events + sev_pos(sev, 0);
+ sev->ops->merge(&kev->event, &second_oldest->event);
+ }
+ }
+
+ /* Take one and fill it. */
+ kev = sev->events + sev_pos(sev, sev->in_use);
+ kev->event.type = ev->type;
+ if (copy_payload)
+ kev->event.u = ev->u;
+ kev->event.id = ev->id;
+ kev->event.timestamp = *ts;
+ kev->event.sequence = fh->sequence;
+ sev->in_use++;
+ list_add_tail(&kev->list, &fh->available);
+
+ fh->navailable++;
+
+ wake_up_all(&fh->wait);
+}
+
+void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
+{
+ struct v4l2_fh *fh;
+ unsigned long flags;
+ struct timespec timestamp;
+
+ ktime_get_ts(×tamp);
+
+ spin_lock_irqsave(&vdev->fh_lock, flags);
+
+ list_for_each_entry(fh, &vdev->fh_list, list)
+ __v4l2_event_queue_fh(fh, ev, ×tamp);
+
+ spin_unlock_irqrestore(&vdev->fh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_queue);
+
+void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev)
+{
+ unsigned long flags;
+ struct timespec timestamp;
+
+ ktime_get_ts(×tamp);
+
+ spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+ __v4l2_event_queue_fh(fh, ev, ×tamp);
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_queue_fh);
+
+int v4l2_event_pending(struct v4l2_fh *fh)
+{
+ return fh->navailable;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_pending);
+
+int v4l2_event_subscribe(struct v4l2_fh *fh,
+ const struct v4l2_event_subscription *sub, unsigned elems,
+ const struct v4l2_subscribed_event_ops *ops)
+{
+ struct v4l2_subscribed_event *sev, *found_ev;
+ unsigned long flags;
+ unsigned i;
+
+ if (sub->type == V4L2_EVENT_ALL)
+ return -EINVAL;
+
+ if (elems < 1)
+ elems = 1;
+
+ sev = kzalloc(sizeof(*sev) + sizeof(struct v4l2_kevent) * elems, GFP_KERNEL);
+ if (!sev)
+ return -ENOMEM;
+ for (i = 0; i < elems; i++)
+ sev->events[i].sev = sev;
+ sev->type = sub->type;
+ sev->id = sub->id;
+ sev->flags = sub->flags;
+ sev->fh = fh;
+ sev->ops = ops;
+
+ spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+ found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
+ if (!found_ev)
+ list_add(&sev->list, &fh->subscribed);
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+ if (found_ev) {
+ kfree(sev);
+ return 0; /* Already listening */
+ }
+
+ if (sev->ops && sev->ops->add) {
+ int ret = sev->ops->add(sev, elems);
+ if (ret) {
+ sev->ops = NULL;
+ v4l2_event_unsubscribe(fh, sub);
+ return ret;
+ }
+ }
+
+ /* Mark as ready for use */
+ sev->elems = elems;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
+
+void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
+{
+ struct v4l2_event_subscription sub;
+ struct v4l2_subscribed_event *sev;
+ unsigned long flags;
+
+ do {
+ sev = NULL;
+
+ spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+ if (!list_empty(&fh->subscribed)) {
+ sev = list_first_entry(&fh->subscribed,
+ struct v4l2_subscribed_event, list);
+ sub.type = sev->type;
+ sub.id = sev->id;
+ }
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+ if (sev)
+ v4l2_event_unsubscribe(fh, &sub);
+ } while (sev);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all);
+
+int v4l2_event_unsubscribe(struct v4l2_fh *fh,
+ const struct v4l2_event_subscription *sub)
+{
+ struct v4l2_subscribed_event *sev;
+ unsigned long flags;
+ int i;
+
+ if (sub->type == V4L2_EVENT_ALL) {
+ v4l2_event_unsubscribe_all(fh);
+ return 0;
+ }
+
+ spin_lock_irqsave(&fh->vdev->fh_lock, flags);
+
+ sev = v4l2_event_subscribed(fh, sub->type, sub->id);
+ if (sev != NULL) {
+ /* Remove any pending events for this subscription */
+ for (i = 0; i < sev->in_use; i++) {
+ list_del(&sev->events[sev_pos(sev, i)].list);
+ fh->navailable--;
+ }
+ list_del(&sev->list);
+ }
+
+ spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
+
+ if (sev && sev->ops && sev->ops->del)
+ sev->ops->del(sev);
+
+ kfree(sev);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe);
+
+int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
+ struct v4l2_event_subscription *sub)
+{
+ return v4l2_event_unsubscribe(fh, sub);
+}
+EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe);
+
+static void v4l2_event_src_replace(struct v4l2_event *old,
+ const struct v4l2_event *new)
+{
+ u32 old_changes = old->u.src_change.changes;
+
+ old->u.src_change = new->u.src_change;
+ old->u.src_change.changes |= old_changes;
+}
+
+static void v4l2_event_src_merge(const struct v4l2_event *old,
+ struct v4l2_event *new)
+{
+ new->u.src_change.changes |= old->u.src_change.changes;
+}
+
+static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = {
+ .replace = v4l2_event_src_replace,
+ .merge = v4l2_event_src_merge,
+};
+
+int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
+ const struct v4l2_event_subscription *sub)
+{
+ if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
+ return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe);
+
+int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
+ struct v4l2_fh *fh, struct v4l2_event_subscription *sub)
+{
+ return v4l2_src_change_event_subscribe(fh, sub);
+}
+EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);
Code Review / kvmfornfv.git / blobdiff