Orange Pi5 kernel

// 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 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;
<------>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);
 
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 elems,
<------><------><------> const struct v4l2_subscribed_event_ops *ops)
{
<------>struct v4l2_subscribed_event *sev, *found_ev;
<------>unsigned long flags;
<------>unsigned 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);