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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/media/v4l2-core/v4l2-event.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-event.c')
-rw-r--r-- | drivers/media/v4l2-core/v4l2-event.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-event.c b/drivers/media/v4l2-core/v4l2-event.c new file mode 100644 index 000000000..c5ce9f11a --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-event.c @@ -0,0 +1,373 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * v4l2-event.c + * + * V4L2 events. + * + * Copyright (C) 2009--2010 Nokia Corporation. + * + * Contact: Sakari Ailus <sakari.ailus@iki.fi> + */ + +#include <media/v4l2-dev.h> +#include <media/v4l2-fh.h> +#include <media/v4l2-event.h> + +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/export.h> + +static unsigned int sev_pos(const struct v4l2_subscribed_event *sev, unsigned int 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; + struct timespec64 ts; + 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; + ts = ns_to_timespec64(kev->ts); + event->timestamp.tv_sec = ts.tv_sec; + event->timestamp.tv_nsec = ts.tv_nsec; + 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, u64 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; + + /* 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->ts = 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; + u64 ts; + + if (vdev == NULL) + return; + + ts = ktime_get_ns(); + + spin_lock_irqsave(&vdev->fh_lock, flags); + + list_for_each_entry(fh, &vdev->fh_list, list) + __v4l2_event_queue_fh(fh, ev, ts); + + 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; + u64 ts = ktime_get_ns(); + + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + __v4l2_event_queue_fh(fh, ev, ts); + 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); + +void v4l2_event_wake_all(struct video_device *vdev) +{ + struct v4l2_fh *fh; + unsigned long flags; + + if (!vdev) + return; + + spin_lock_irqsave(&vdev->fh_lock, flags); + + list_for_each_entry(fh, &vdev->fh_list, list) + wake_up_all(&fh->wait); + + spin_unlock_irqrestore(&vdev->fh_lock, flags); +} +EXPORT_SYMBOL_GPL(v4l2_event_wake_all); + +static void __v4l2_event_unsubscribe(struct v4l2_subscribed_event *sev) +{ + struct v4l2_fh *fh = sev->fh; + unsigned int i; + + lockdep_assert_held(&fh->subscribe_lock); + assert_spin_locked(&fh->vdev->fh_lock); + + /* 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); +} + +int v4l2_event_subscribe(struct v4l2_fh *fh, + const struct v4l2_event_subscription *sub, unsigned int elems, + const struct v4l2_subscribed_event_ops *ops) +{ + struct v4l2_subscribed_event *sev, *found_ev; + unsigned long flags; + unsigned int i; + int ret = 0; + + if (sub->type == V4L2_EVENT_ALL) + return -EINVAL; + + if (elems < 1) + elems = 1; + + sev = kvzalloc(struct_size(sev, events, 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; + sev->elems = elems; + + mutex_lock(&fh->subscribe_lock); + + 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) { + /* Already listening */ + kvfree(sev); + } else if (sev->ops && sev->ops->add) { + ret = sev->ops->add(sev, elems); + if (ret) { + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + __v4l2_event_unsubscribe(sev); + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); + kvfree(sev); + } + } + + mutex_unlock(&fh->subscribe_lock); + + return ret; +} +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; + + if (sub->type == V4L2_EVENT_ALL) { + v4l2_event_unsubscribe_all(fh); + return 0; + } + + mutex_lock(&fh->subscribe_lock); + + spin_lock_irqsave(&fh->vdev->fh_lock, flags); + + sev = v4l2_event_subscribed(fh, sub->type, sub->id); + if (sev != NULL) + __v4l2_event_unsubscribe(sev); + + spin_unlock_irqrestore(&fh->vdev->fh_lock, flags); + + if (sev && sev->ops && sev->ops->del) + sev->ops->del(sev); + + mutex_unlock(&fh->subscribe_lock); + + kvfree(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); |