Hi Hans,
Thanks for the patchset! This looks really nice!
Hans Verkuil wrote:
> Whenever a control changes value an event is sent to anyone that subscribed
> to it.
>
> Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
> ---
> drivers/media/video/v4l2-ctrls.c | 59 ++++++++++++++++++
> drivers/media/video/v4l2-event.c | 126
> +++++++++++++++++++++++++++-----------
> drivers/media/video/v4l2-fh.c | 4 +-
> include/linux/videodev2.h | 17 +++++-
> include/media/v4l2-ctrls.h | 9 +++
> include/media/v4l2-event.h | 2 +
> 6 files changed, 177 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/media/video/v4l2-ctrls.c
> b/drivers/media/video/v4l2-ctrls.c
> index f75a1d4..163f412 100644
> --- a/drivers/media/video/v4l2-ctrls.c
> +++ b/drivers/media/video/v4l2-ctrls.c
> @@ -23,6 +23,7 @@
> #include <media/v4l2-ioctl.h>
> #include <media/v4l2-device.h>
> #include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> #include <media/v4l2-dev.h>
>
> /* Internal temporary helper struct, one for each v4l2_ext_control */
> @@ -537,6 +538,16 @@ static bool type_is_int(const struct v4l2_ctrl *ctrl)
> }
> }
>
> +static void send_event(struct v4l2_ctrl *ctrl, struct v4l2_event *ev)
> +{
> + struct v4l2_ctrl_fh *pos;
> +
> + ev->id = ctrl->id;
> + list_for_each_entry(pos, &ctrl->fhs, node) {
> + v4l2_event_queue_fh(pos->fh, ev);
> + }
No need for braces here.
> +}
> +
> /* Helper function: copy the current control value back to the caller */
> static int cur_to_user(struct v4l2_ext_control *c,
> struct v4l2_ctrl *ctrl)
> @@ -626,20 +637,38 @@ static int new_to_user(struct v4l2_ext_control *c,
> /* Copy the new value to the current value. */
> static void new_to_cur(struct v4l2_ctrl *ctrl)
> {
> + struct v4l2_event ev;
> + bool changed = false;
> +
> if (ctrl == NULL)
> return;
> switch (ctrl->type) {
> + case V4L2_CTRL_TYPE_BUTTON:
> + changed = true;
> + ev.u.ctrl_ch_value.value = 0;
> + break;
> case V4L2_CTRL_TYPE_STRING:
> /* strings are always 0-terminated */
> + changed = strcmp(ctrl->string, ctrl->cur.string);
> strcpy(ctrl->cur.string, ctrl->string);
> + ev.u.ctrl_ch_value.value64 = 0;
> break;
> case V4L2_CTRL_TYPE_INTEGER64:
> + changed = ctrl->val64 != ctrl->cur.val64;
> ctrl->cur.val64 = ctrl->val64;
> + ev.u.ctrl_ch_value.value64 = ctrl->val64;
> break;
> default:
> + changed = ctrl->val != ctrl->cur.val;
> ctrl->cur.val = ctrl->val;
> + ev.u.ctrl_ch_value.value = ctrl->val;
> break;
> }
> + if (changed) {
> + ev.type = V4L2_EVENT_CTRL_CH_VALUE;
> + ev.u.ctrl_ch_value.type = ctrl->type;
> + send_event(ctrl, &ev);
> + }
> }
>
> /* Copy the current value to the new value */
> @@ -784,6 +813,7 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler *hdl)
> {
> struct v4l2_ctrl_ref *ref, *next_ref;
> struct v4l2_ctrl *ctrl, *next_ctrl;
> + struct v4l2_ctrl_fh *ctrl_fh, *next_ctrl_fh;
>
> if (hdl == NULL || hdl->buckets == NULL)
> return;
> @@ -797,6 +827,10 @@ void v4l2_ctrl_handler_free(struct v4l2_ctrl_handler
> *hdl)
> /* Free all controls owned by the handler */
> list_for_each_entry_safe(ctrl, next_ctrl, &hdl->ctrls, node) {
> list_del(&ctrl->node);
> + list_for_each_entry_safe(ctrl_fh, next_ctrl_fh, &ctrl->fhs,
> node) {
> + list_del(&ctrl_fh->node);
> + kfree(ctrl_fh);
> + }
> kfree(ctrl);
> }
> kfree(hdl->buckets);
> @@ -1003,6 +1037,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct
> v4l2_ctrl_handler *hdl,
> }
>
> INIT_LIST_HEAD(&ctrl->node);
> + INIT_LIST_HEAD(&ctrl->fhs);
> ctrl->handler = hdl;
> ctrl->ops = ops;
> ctrl->id = id;
> @@ -1888,3 +1923,27 @@ int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
> return set_ctrl(ctrl, &val);
> }
> EXPORT_SYMBOL(v4l2_ctrl_s_ctrl);
> +
> +void v4l2_ctrl_add_fh(struct v4l2_ctrl *ctrl, struct v4l2_ctrl_fh *ctrl_fh)
> +{
> + v4l2_ctrl_lock(ctrl);
> + list_add_tail(&ctrl_fh->node, &ctrl->fhs);
> + v4l2_ctrl_unlock(ctrl);
> +}
> +EXPORT_SYMBOL(v4l2_ctrl_add_fh);
> +
> +void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh)
> +{
> + struct v4l2_ctrl_fh *pos;
> +
> + v4l2_ctrl_lock(ctrl);
> + list_for_each_entry(pos, &ctrl->fhs, node) {
> + if (pos->fh == fh) {
> + list_del(&pos->node);
> + kfree(pos);
> + break;
> + }
> + }
> + v4l2_ctrl_unlock(ctrl);
> +}
> +EXPORT_SYMBOL(v4l2_ctrl_del_fh);
> diff --git a/drivers/media/video/v4l2-event.c
> b/drivers/media/video/v4l2-event.c
> index 69fd343..c9251a5 100644
> --- a/drivers/media/video/v4l2-event.c
> +++ b/drivers/media/video/v4l2-event.c
> @@ -25,10 +25,13 @@
> #include <media/v4l2-dev.h>
> #include <media/v4l2-fh.h>
> #include <media/v4l2-event.h>
> +#include <media/v4l2-ctrls.h>
>
> #include <linux/sched.h>
> #include <linux/slab.h>
>
> +static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
> +
> int v4l2_event_init(struct v4l2_fh *fh)
> {
> fh->events = kzalloc(sizeof(*fh->events), GFP_KERNEL);
> @@ -91,7 +94,7 @@ void v4l2_event_free(struct v4l2_fh *fh)
>
> list_kfree(&events->free, struct v4l2_kevent, list);
> list_kfree(&events->available, struct v4l2_kevent, list);
> - list_kfree(&events->subscribed, struct v4l2_subscribed_event, list);
> + v4l2_event_unsubscribe_all(fh);
>
> kfree(events);
> fh->events = NULL;
> @@ -154,9 +157,9 @@ int v4l2_event_dequeue(struct v4l2_fh *fh, struct
> v4l2_event *event,
> }
> EXPORT_SYMBOL_GPL(v4l2_event_dequeue);
>
> -/* Caller must hold fh->event->lock! */
> +/* Caller must hold fh->vdev->fh_lock! */
> static struct v4l2_subscribed_event *v4l2_event_subscribed(
> - struct v4l2_fh *fh, u32 type)
> + struct v4l2_fh *fh, u32 type, u32 id)
> {
> struct v4l2_events *events = fh->events;
> struct v4l2_subscribed_event *sev;
> @@ -164,13 +167,46 @@ static struct v4l2_subscribed_event
> *v4l2_event_subscribed(
> assert_spin_locked(&fh->vdev->fh_lock);
>
> list_for_each_entry(sev, &events->subscribed, list) {
> - if (sev->type == type)
> + 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_events *events = fh->events;
> + struct v4l2_subscribed_event *sev;
> + struct v4l2_kevent *kev;
> +
> + /* Are we subscribed? */
> + sev = v4l2_event_subscribed(fh, ev->type, ev->id);
> + if (sev == NULL)
> + return;
> +
> + /* Increase event sequence number on fh. */
> + events->sequence++;
> +
> + /* Do we have any free events? */
> + if (list_empty(&events->free))
> + return;
> +
> + /* Take one and fill it. */
> + kev = list_first_entry(&events->free, struct v4l2_kevent, list);
> + kev->event.type = ev->type;
> + kev->event.u = ev->u;
> + kev->event.id = ev->id;
> + kev->event.timestamp = *ts;
> + kev->event.sequence = events->sequence;
> + list_move_tail(&kev->list, &events->available);
> +
> + events->navailable++;
> +
> + wake_up_all(&events->wait);
> +}
> +
> void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev)
> {
> struct v4l2_fh *fh;
> @@ -182,37 +218,26 @@ void v4l2_event_queue(struct video_device *vdev, const
> struct v4l2_event *ev)
> spin_lock_irqsave(&vdev->fh_lock, flags);
>
> list_for_each_entry(fh, &vdev->fh_list, list) {
> - struct v4l2_events *events = fh->events;
> - struct v4l2_kevent *kev;
> -
> - /* Are we subscribed? */
> - if (!v4l2_event_subscribed(fh, ev->type))
> - continue;
> -
> - /* Increase event sequence number on fh. */
> - events->sequence++;
> -
> - /* Do we have any free events? */
> - if (list_empty(&events->free))
> - continue;
> -
> - /* Take one and fill it. */
> - kev = list_first_entry(&events->free, struct v4l2_kevent, list);
> - kev->event.type = ev->type;
> - kev->event.u = ev->u;
> - kev->event.timestamp = timestamp;
> - kev->event.sequence = events->sequence;
> - list_move_tail(&kev->list, &events->available);
> -
> - events->navailable++;
> -
> - wake_up_all(&events->wait);
> + __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->events->navailable;
> @@ -223,7 +248,9 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
> struct v4l2_event_subscription *sub)
> {
> struct v4l2_events *events = fh->events;
> - struct v4l2_subscribed_event *sev;
> + struct v4l2_subscribed_event *sev, *found_ev;
> + struct v4l2_ctrl *ctrl = NULL;
> + struct v4l2_ctrl_fh *ctrl_fh = NULL;
> unsigned long flags;
>
> if (fh->events == NULL) {
> @@ -231,15 +258,31 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
> return -ENOMEM;
> }
>
> + if (sub->type == V4L2_EVENT_CTRL_CH_VALUE) {
> + ctrl = v4l2_ctrl_find(fh->ctrl_handler, sub->id);
> + if (ctrl == NULL)
> + return -EINVAL;
> + }
> +
> sev = kmalloc(sizeof(*sev), GFP_KERNEL);
> if (!sev)
> return -ENOMEM;
> + if (ctrl) {
> + ctrl_fh = kzalloc(sizeof(*ctrl_fh), GFP_KERNEL);
> + if (!ctrl_fh) {
> + kfree(sev);
> + return -ENOMEM;
> + }
> + ctrl_fh->fh = fh;
> + }
>
> spin_lock_irqsave(&fh->vdev->fh_lock, flags);
>
> - if (v4l2_event_subscribed(fh, sub->type) == NULL) {
> + found_ev = v4l2_event_subscribed(fh, sub->type, sub->id);
> + if (!found_ev) {
> INIT_LIST_HEAD(&sev->list);
> sev->type = sub->type;
> + sev->id = sub->id;
>
> list_add(&sev->list, &events->subscribed);
> sev = NULL;
> @@ -247,6 +290,10 @@ int v4l2_event_subscribe(struct v4l2_fh *fh,
>
> spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
>
> + /* v4l2_ctrl_add_fh uses a mutex, so do this outside the spin lock */
> + if (!found_ev && ctrl)
> + v4l2_ctrl_add_fh(ctrl, ctrl_fh);
> +
> kfree(sev);
>
> return 0;
> @@ -256,6 +303,7 @@ EXPORT_SYMBOL_GPL(v4l2_event_subscribe);
> static void v4l2_event_unsubscribe_all(struct v4l2_fh *fh)
> {
> struct v4l2_events *events = fh->events;
> + struct v4l2_event_subscription sub;
> struct v4l2_subscribed_event *sev;
> unsigned long flags;
>
> @@ -265,11 +313,13 @@ static void v4l2_event_unsubscribe_all(struct v4l2_fh
> *fh)
> spin_lock_irqsave(&fh->vdev->fh_lock, flags);
> if (!list_empty(&events->subscribed)) {
> sev = list_first_entry(&events->subscribed,
> - struct v4l2_subscribed_event, list);
> - list_del(&sev->list);
> + struct v4l2_subscribed_event, list);
> + sub.type = sev->type;
> + sub.id = sev->id;
> }
> spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
> - kfree(sev);
> + if (sev)
> + v4l2_event_unsubscribe(fh, &sub);
> } while (sev);
> }
>
> @@ -286,11 +336,17 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
>
> spin_lock_irqsave(&fh->vdev->fh_lock, flags);
>
> - sev = v4l2_event_subscribed(fh, sub->type);
> + sev = v4l2_event_subscribed(fh, sub->type, sub->id);
> if (sev != NULL)
> list_del(&sev->list);
>
> spin_unlock_irqrestore(&fh->vdev->fh_lock, flags);
> + if (sev->type == V4L2_EVENT_CTRL_CH_VALUE) {
> + struct v4l2_ctrl *ctrl = v4l2_ctrl_find(fh->ctrl_handler,
> sev->id);
> +
> + if (ctrl)
> + v4l2_ctrl_del_fh(ctrl, fh);
> + }
>
> kfree(sev);
>
> diff --git a/drivers/media/video/v4l2-fh.c b/drivers/media/video/v4l2-fh.c
> index 8635011..c6aef84 100644
> --- a/drivers/media/video/v4l2-fh.c
> +++ b/drivers/media/video/v4l2-fh.c
> @@ -93,10 +93,8 @@ void v4l2_fh_exit(struct v4l2_fh *fh)
> {
> if (fh->vdev == NULL)
> return;
> -
> - fh->vdev = NULL;
> -
> v4l2_event_free(fh);
> + fh->vdev = NULL;
This looks like a bugfix.
> }
> EXPORT_SYMBOL_GPL(v4l2_fh_exit);
>
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 92d2fdd..f7238c1 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -1787,6 +1787,7 @@ struct v4l2_streamparm {
> #define V4L2_EVENT_ALL 0
> #define V4L2_EVENT_VSYNC 1
> #define V4L2_EVENT_EOS 2
> +#define V4L2_EVENT_CTRL_CH_VALUE 3
> #define V4L2_EVENT_PRIVATE_START 0x08000000
>
> /* Payload for V4L2_EVENT_VSYNC */
> @@ -1795,21 +1796,33 @@ struct v4l2_event_vsync {
> __u8 field;
> } __attribute__ ((packed));
>
> +/* Payload for V4L2_EVENT_CTRL_CH_VALUE */
> +struct v4l2_event_ctrl_ch_value {
> + __u32 type;
type is enum v4l2_ctrl_type in struct v4l2_ctrl and struct v4l2_queryctrl.
> + union {
> + __s32 value;
> + __s64 value64;
> + };
> +} __attribute__ ((packed));
> +
> struct v4l2_event {
> __u32 type;
> union {
> struct v4l2_event_vsync vsync;
> + struct v4l2_event_ctrl_ch_value ctrl_ch_value;
> __u8 data[64];
> } u;
> __u32 pending;
> __u32 sequence;
> struct timespec timestamp;
> - __u32 reserved[9];
> + __u32 id;
id is valid only for control related events. Shouldn't it be part of the
control related structures instead, or another union for control related
event types? E.g.
struct {
enum v4l2_ctrl_type id;
union {
struct v4l2_event_ctrl_ch_value ch_value;
};
} ctrl;
> + __u32 reserved[8];
> };
>
> struct v4l2_event_subscription {
> __u32 type;
> - __u32 reserved[7];
> + __u32 id;
> + __u32 reserved[6];
> };
Similar situation here, but no existing union where id would fit in.
> /*
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 97d0638..7ca45a5 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -30,6 +30,7 @@ struct v4l2_ctrl_handler;
> struct v4l2_ctrl;
> struct video_device;
> struct v4l2_subdev;
> +struct v4l2_fh;
>
> /** struct v4l2_ctrl_ops - The control operations that the driver has to
> provide.
> * @g_volatile_ctrl: Get a new value for this control. Generally only
> relevant
> @@ -97,6 +98,7 @@ struct v4l2_ctrl_ops {
> struct v4l2_ctrl {
> /* Administrative fields */
> struct list_head node;
> + struct list_head fhs;
> struct v4l2_ctrl_handler *handler;
> struct v4l2_ctrl **cluster;
> unsigned ncontrols;
> @@ -168,6 +170,11 @@ struct v4l2_ctrl_handler {
> int error;
> };
>
> +struct v4l2_ctrl_fh {
> + struct list_head node;
> + struct v4l2_fh *fh;
> +};
> +
> /** struct v4l2_ctrl_config - Control configuration structure.
> * @ops: The control ops.
> * @id: The control ID.
> @@ -440,6 +447,8 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
> */
> int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
>
> +void v4l2_ctrl_add_fh(struct v4l2_ctrl *ctrl, struct v4l2_ctrl_fh *ctrl_fh);
> +void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh);
>
> /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL.
> */
> int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
> diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
> index 3b86177..45e9c1e 100644
> --- a/include/media/v4l2-event.h
> +++ b/include/media/v4l2-event.h
> @@ -40,6 +40,7 @@ struct v4l2_kevent {
> struct v4l2_subscribed_event {
> struct list_head list;
> u32 type;
> + u32 id;
> };
And here.
> struct v4l2_events {
> @@ -58,6 +59,7 @@ void v4l2_event_free(struct v4l2_fh *fh);
> int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
> int nonblocking);
> void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event
> *ev);
> +void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
> int v4l2_event_pending(struct v4l2_fh *fh);
> int v4l2_event_subscribe(struct v4l2_fh *fh,
> struct v4l2_event_subscription *sub);
Regards,
--
Sakari Ailus
sakari.ai...@maxwell.research.nokia.com
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