From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/media/v4l2-core/v4l2-event.c | 356 +++++++++++++++++++++++++++++++++++ 1 file changed, 356 insertions(+) create mode 100644 drivers/media/v4l2-core/v4l2-event.c (limited to 'drivers/media/v4l2-core/v4l2-event.c') diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c new file mode 100644 index 000000000..8761aab99 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-event.c @@ -0,0 +1,356 @@ +/* + * v4l2-event.c + * + * V4L2 events. + * + * Copyright (C) 2009--2010 Nokia Corporation. + * + * Contact: Sakari Ailus + * + * 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 +#include +#include + +#include +#include +#include + +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); -- cgit v1.2.3-54-g00ecf