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373 lines
8.5 KiB
373 lines
8.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* v4l2-event.c |
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* |
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* V4L2 events. |
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* |
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* Copyright (C) 2009--2010 Nokia Corporation. |
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* |
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* Contact: Sakari Ailus <[email protected]> |
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*/ |
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#include <media/v4l2-dev.h> |
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#include <media/v4l2-fh.h> |
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#include <media/v4l2-event.h> |
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#include <linux/mm.h> |
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#include <linux/sched.h> |
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#include <linux/slab.h> |
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#include <linux/export.h> |
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static unsigned sev_pos(const struct v4l2_subscribed_event *sev, unsigned idx) |
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{ |
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idx += sev->first; |
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return idx >= sev->elems ? idx - sev->elems : idx; |
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} |
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static int __v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event) |
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{ |
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struct v4l2_kevent *kev; |
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struct timespec64 ts; |
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unsigned long flags; |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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if (list_empty(&fh->available)) { |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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return -ENOENT; |
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} |
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WARN_ON(fh->navailable == 0); |
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kev = list_first_entry(&fh->available, struct v4l2_kevent, list); |
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list_del(&kev->list); |
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fh->navailable--; |
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kev->event.pending = fh->navailable; |
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*event = kev->event; |
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ts = ns_to_timespec64(kev->ts); |
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event->timestamp.tv_sec = ts.tv_sec; |
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event->timestamp.tv_nsec = ts.tv_nsec; |
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kev->sev->first = sev_pos(kev->sev, 1); |
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kev->sev->in_use--; |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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return 0; |
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} |
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int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event, |
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int nonblocking) |
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{ |
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int ret; |
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if (nonblocking) |
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return __v4l2_event_dequeue(fh, event); |
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/* Release the vdev lock while waiting */ |
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if (fh->vdev->lock) |
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mutex_unlock(fh->vdev->lock); |
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do { |
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ret = wait_event_interruptible(fh->wait, |
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fh->navailable != 0); |
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if (ret < 0) |
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break; |
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ret = __v4l2_event_dequeue(fh, event); |
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} while (ret == -ENOENT); |
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if (fh->vdev->lock) |
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mutex_lock(fh->vdev->lock); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_dequeue); |
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/* Caller must hold fh->vdev->fh_lock! */ |
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static struct v4l2_subscribed_event *v4l2_event_subscribed( |
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struct v4l2_fh *fh, u32 type, u32 id) |
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{ |
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struct v4l2_subscribed_event *sev; |
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assert_spin_locked(&fh->vdev->fh_lock); |
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list_for_each_entry(sev, &fh->subscribed, list) |
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if (sev->type == type && sev->id == id) |
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return sev; |
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return NULL; |
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} |
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static void __v4l2_event_queue_fh(struct v4l2_fh *fh, |
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const struct v4l2_event *ev, u64 ts) |
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{ |
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struct v4l2_subscribed_event *sev; |
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struct v4l2_kevent *kev; |
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bool copy_payload = true; |
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/* Are we subscribed? */ |
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sev = v4l2_event_subscribed(fh, ev->type, ev->id); |
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if (sev == NULL) |
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return; |
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/* Increase event sequence number on fh. */ |
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fh->sequence++; |
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/* Do we have any free events? */ |
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if (sev->in_use == sev->elems) { |
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/* no, remove the oldest one */ |
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kev = sev->events + sev_pos(sev, 0); |
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list_del(&kev->list); |
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sev->in_use--; |
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sev->first = sev_pos(sev, 1); |
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fh->navailable--; |
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if (sev->elems == 1) { |
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if (sev->ops && sev->ops->replace) { |
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sev->ops->replace(&kev->event, ev); |
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copy_payload = false; |
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} |
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} else if (sev->ops && sev->ops->merge) { |
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struct v4l2_kevent *second_oldest = |
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sev->events + sev_pos(sev, 0); |
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sev->ops->merge(&kev->event, &second_oldest->event); |
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} |
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} |
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/* Take one and fill it. */ |
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kev = sev->events + sev_pos(sev, sev->in_use); |
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kev->event.type = ev->type; |
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if (copy_payload) |
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kev->event.u = ev->u; |
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kev->event.id = ev->id; |
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kev->ts = ts; |
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kev->event.sequence = fh->sequence; |
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sev->in_use++; |
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list_add_tail(&kev->list, &fh->available); |
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fh->navailable++; |
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wake_up_all(&fh->wait); |
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} |
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void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev) |
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{ |
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struct v4l2_fh *fh; |
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unsigned long flags; |
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u64 ts; |
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if (vdev == NULL) |
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return; |
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ts = ktime_get_ns(); |
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spin_lock_irqsave(&vdev->fh_lock, flags); |
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list_for_each_entry(fh, &vdev->fh_list, list) |
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__v4l2_event_queue_fh(fh, ev, ts); |
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spin_unlock_irqrestore(&vdev->fh_lock, flags); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_queue); |
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void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev) |
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{ |
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unsigned long flags; |
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u64 ts = ktime_get_ns(); |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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__v4l2_event_queue_fh(fh, ev, ts); |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_queue_fh); |
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int v4l2_event_pending(struct v4l2_fh *fh) |
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{ |
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return fh->navailable; |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_pending); |
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void v4l2_event_wake_all(struct video_device *vdev) |
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{ |
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struct v4l2_fh *fh; |
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unsigned long flags; |
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if (!vdev) |
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return; |
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spin_lock_irqsave(&vdev->fh_lock, flags); |
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list_for_each_entry(fh, &vdev->fh_list, list) |
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wake_up_all(&fh->wait); |
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spin_unlock_irqrestore(&vdev->fh_lock, flags); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_wake_all); |
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static void __v4l2_event_unsubscribe(struct v4l2_subscribed_event *sev) |
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{ |
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struct v4l2_fh *fh = sev->fh; |
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unsigned int i; |
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lockdep_assert_held(&fh->subscribe_lock); |
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assert_spin_locked(&fh->vdev->fh_lock); |
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/* Remove any pending events for this subscription */ |
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for (i = 0; i < sev->in_use; i++) { |
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list_del(&sev->events[sev_pos(sev, i)].list); |
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fh->navailable--; |
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} |
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list_del(&sev->list); |
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} |
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int v4l2_event_subscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub, unsigned elems, |
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const struct v4l2_subscribed_event_ops *ops) |
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{ |
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struct v4l2_subscribed_event *sev, *found_ev; |
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unsigned long flags; |
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unsigned i; |
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int ret = 0; |
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if (sub->type == V4L2_EVENT_ALL) |
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return -EINVAL; |
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if (elems < 1) |
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elems = 1; |
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sev = kvzalloc(struct_size(sev, events, elems), GFP_KERNEL); |
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if (!sev) |
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return -ENOMEM; |
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for (i = 0; i < elems; i++) |
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sev->events[i].sev = sev; |
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sev->type = sub->type; |
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sev->id = sub->id; |
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sev->flags = sub->flags; |
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sev->fh = fh; |
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sev->ops = ops; |
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sev->elems = elems; |
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mutex_lock(&fh->subscribe_lock); |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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found_ev = v4l2_event_subscribed(fh, sub->type, sub->id); |
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if (!found_ev) |
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list_add(&sev->list, &fh->subscribed); |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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if (found_ev) { |
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/* Already listening */ |
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kvfree(sev); |
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} else if (sev->ops && sev->ops->add) { |
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ret = sev->ops->add(sev, elems); |
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if (ret) { |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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__v4l2_event_unsubscribe(sev); |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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kvfree(sev); |
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} |
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} |
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mutex_unlock(&fh->subscribe_lock); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_subscribe); |
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void v4l2_event_unsubscribe_all(struct v4l2_fh *fh) |
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{ |
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struct v4l2_event_subscription sub; |
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struct v4l2_subscribed_event *sev; |
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unsigned long flags; |
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do { |
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sev = NULL; |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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if (!list_empty(&fh->subscribed)) { |
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sev = list_first_entry(&fh->subscribed, |
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struct v4l2_subscribed_event, list); |
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sub.type = sev->type; |
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sub.id = sev->id; |
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} |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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if (sev) |
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v4l2_event_unsubscribe(fh, &sub); |
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} while (sev); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe_all); |
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int v4l2_event_unsubscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub) |
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{ |
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struct v4l2_subscribed_event *sev; |
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unsigned long flags; |
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if (sub->type == V4L2_EVENT_ALL) { |
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v4l2_event_unsubscribe_all(fh); |
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return 0; |
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} |
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mutex_lock(&fh->subscribe_lock); |
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spin_lock_irqsave(&fh->vdev->fh_lock, flags); |
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sev = v4l2_event_subscribed(fh, sub->type, sub->id); |
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if (sev != NULL) |
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__v4l2_event_unsubscribe(sev); |
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spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); |
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if (sev && sev->ops && sev->ops->del) |
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sev->ops->del(sev); |
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mutex_unlock(&fh->subscribe_lock); |
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kvfree(sev); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_unsubscribe); |
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int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh, |
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struct v4l2_event_subscription *sub) |
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{ |
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return v4l2_event_unsubscribe(fh, sub); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe); |
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static void v4l2_event_src_replace(struct v4l2_event *old, |
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const struct v4l2_event *new) |
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{ |
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u32 old_changes = old->u.src_change.changes; |
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old->u.src_change = new->u.src_change; |
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old->u.src_change.changes |= old_changes; |
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} |
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static void v4l2_event_src_merge(const struct v4l2_event *old, |
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struct v4l2_event *new) |
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{ |
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new->u.src_change.changes |= old->u.src_change.changes; |
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} |
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static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = { |
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.replace = v4l2_event_src_replace, |
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.merge = v4l2_event_src_merge, |
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}; |
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int v4l2_src_change_event_subscribe(struct v4l2_fh *fh, |
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const struct v4l2_event_subscription *sub) |
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{ |
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if (sub->type == V4L2_EVENT_SOURCE_CHANGE) |
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return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops); |
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return -EINVAL; |
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} |
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EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe); |
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int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd, |
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struct v4l2_fh *fh, struct v4l2_event_subscription *sub) |
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{ |
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return v4l2_src_change_event_subscribe(fh, sub); |
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} |
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EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);
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