[PATCH 08/10] uvcvideo: Add support for control events

Hans de Goede
2012-03-25T11:55:00Z

drivers/media/video/uvc/uvc_ctrl.c | 119 +++++++++++++++++++++++++++++++++++-
drivers/media/video/uvc/uvc_v4l2.c | 42 ++++++++++---
drivers/media/video/uvc/uvcvideo.h | 18 ++++--
3 files changed, 165 insertions(+), 14 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index fc979c6..742496f 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -21,6 +21,7 @@
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/atomic.h>
+#include <media/v4l2-ctrls.h>

#include "uvcvideo.h"

@@ -1104,6 +1105,116 @@ done:
return ret;
}

+/* --------------------------------------------------------------------------
+ * Ctrl event handling
+ */
+
+static void uvc_ctrl_fill_event(struct uvc_video_chain *chain,
+ struct v4l2_event *ev,
+ struct uvc_control *ctrl,
+ struct uvc_control_mapping *mapping,
+ s32 value, u32 changes)
+{
+ struct v4l2_queryctrl v4l2_ctrl;
+
+ __uvc_query_v4l2_ctrl(chain, ctrl, mapping, &v4l2_ctrl);
+
+ memset(ev->reserved, 0, sizeof(ev->reserved));
+ ev->type = V4L2_EVENT_CTRL;
+ ev->id = v4l2_ctrl.id;
+ ev->u.ctrl.value = value;
+ ev->u.ctrl.changes = changes;
+ ev->u.ctrl.type = v4l2_ctrl.type;
+ ev->u.ctrl.flags = v4l2_ctrl.flags;
+ ev->u.ctrl.minimum = v4l2_ctrl.minimum;
+ ev->u.ctrl.maximum = v4l2_ctrl.maximum;
+ ev->u.ctrl.step = v4l2_ctrl.step;
+ ev->u.ctrl.default_value = v4l2_ctrl.default_value;
+}
+
+static void uvc_ctrl_send_event(struct uvc_fh *handle,
+ struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
+ s32 value, u32 changes)
+{
+ struct v4l2_subscribed_event *sev;
+ struct v4l2_event ev;
+
+ if (list_empty(&mapping->ev_subs))
+ return;
+
+ uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, value, changes);
+
+ list_for_each_entry(sev, &mapping->ev_subs, node)
+ if (sev->fh && (sev->fh != &handle->vfh ||
+ (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK)))
+ v4l2_event_queue_fh(sev->fh, &ev);
+}
+
+static void uvc_ctrl_send_events(struct uvc_fh *handle,
+ struct v4l2_ext_control *xctrls, int xctrls_count)
+{
+ struct uvc_control_mapping *mapping;
+ struct uvc_control *ctrl;
+ int i;
+
+ for (i = 0; i < xctrls_count; ++i) {
+ ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
+ uvc_ctrl_send_event(handle, ctrl, mapping, xctrls[i].value,
+ V4L2_EVENT_CTRL_CH_VALUE);
+ }
+}
+
+static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev)
+{
+ struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
+ struct uvc_control_mapping *mapping;
+ struct uvc_control *ctrl;
+ int ret;
+
+ ret = mutex_lock_interruptible(&handle->chain->ctrl_mutex);
+ if (ret < 0)
+ return -ERESTARTSYS;
+
+ ctrl = uvc_find_control(handle->chain, sev->id, &mapping);
+ if (ctrl == NULL) {
+ ret = -EINVAL;
+ goto done;
+ }
+
+ list_add_tail(&sev->node, &mapping->ev_subs);
+ if (sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL) {
+ struct v4l2_event ev;
+ u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
+ s32 val = 0;
+
+ if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
+ changes |= V4L2_EVENT_CTRL_CH_VALUE;
+
+ uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val,
+ changes);
+ v4l2_event_queue_fh(sev->fh, &ev);
+ }
+
+done:
+ mutex_unlock(&handle->chain->ctrl_mutex);
+ return ret;
+}
+
+static void uvc_ctrl_del_event(struct v4l2_subscribed_event *sev)
+{
+ struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
+
+ mutex_lock(&handle->chain->ctrl_mutex);
+ list_del(&sev->node);
+ mutex_unlock(&handle->chain->ctrl_mutex);
+}
+
+const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops = {
+ .add = uvc_ctrl_add_event,
+ .del = uvc_ctrl_del_event,
+ .replace = v4l2_ctrl_replace,
+ .merge = v4l2_ctrl_merge,
+};

/* --------------------------------------------------------------------------
* Control transactions
@@ -1181,8 +1292,10 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
return 0;
}

-int __uvc_ctrl_commit(struct uvc_video_chain *chain, int rollback)
+int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
+ struct v4l2_ext_control *xctrls, int xctrls_count)
{
+ struct uvc_video_chain *chain = handle->chain;
struct uvc_entity *entity;
int ret = 0;

@@ -1193,6 +1306,8 @@ int __uvc_ctrl_commit(struct uvc_video_chain *chain, int rollback)
goto done;
}

+ if (!rollback)
+ uvc_ctrl_send_events(handle, xctrls, xctrls_count);
done:
mutex_unlock(&chain->ctrl_mutex);
return ret;
@@ -1664,6 +1779,8 @@ static int __uvc_ctrl_add_mapping(struct uvc_device *dev,
if (map == NULL)
return -ENOMEM;

+ INIT_LIST_HEAD(&map->ev_subs);
+
size = sizeof(*mapping->menu_info) * mapping->menu_count;
map->menu_info = kmemdup(mapping->menu_info, size, GFP_KERNEL);
if (map->menu_info == NULL) {
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 8db90ef..f7cf6f5 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -25,6 +25,7 @@
#include <linux/atomic.h>

#include <media/v4l2-common.h>
+#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>

#include "uvcvideo.h"
@@ -505,6 +506,8 @@ static int uvc_v4l2_open(struct file *file)
}
}

+ v4l2_fh_init(&handle->vfh, stream->vdev);
+ v4l2_fh_add(&handle->vfh);
handle->chain = stream->chain;
handle->stream = stream;
handle->state = UVC_HANDLE_PASSIVE;
@@ -528,6 +531,8 @@ static int uvc_v4l2_release(struct file *file)

/* Release the file handle. */
uvc_dismiss_privileges(handle);
+ v4l2_fh_del(&handle->vfh);
+ v4l2_fh_exit(&handle->vfh);
kfree(handle);
file->private_data = NULL;

@@ -584,7 +589,7 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
return ret;

ret = uvc_ctrl_get(chain, &xctrl);
- uvc_ctrl_rollback(chain);
+ uvc_ctrl_rollback(handle);
if (ret >= 0)
ctrl->value = xctrl.value;
break;
@@ -605,10 +610,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)

ret = uvc_ctrl_set(chain, &xctrl);
if (ret < 0) {
- uvc_ctrl_rollback(chain);
+ uvc_ctrl_rollback(handle);
return ret;
}
- ret = uvc_ctrl_commit(chain);
+ ret = uvc_ctrl_commit(handle, &xctrl, 1);
if (ret == 0)
ctrl->value = xctrl.value;
break;
@@ -630,13 +635,13 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_get(chain, ctrl);
if (ret < 0) {
- uvc_ctrl_rollback(chain);
+ uvc_ctrl_rollback(handle);
ctrls->error_idx = i;
return ret;
}
}
ctrls->error_idx = 0;
- ret = uvc_ctrl_rollback(chain);
+ ret = uvc_ctrl_rollback(handle);
break;
}

@@ -654,7 +659,7 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_set(chain, ctrl);
if (ret < 0) {
- uvc_ctrl_rollback(chain);
+ uvc_ctrl_rollback(handle);
ctrls->error_idx = i;
return ret;
}
@@ -663,9 +668,10 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
ctrls->error_idx = 0;

if (cmd == VIDIOC_S_EXT_CTRLS)
- ret = uvc_ctrl_commit(chain);
+ ret = uvc_ctrl_commit(handle,
+ ctrls->controls, ctrls->count);
else
- ret = uvc_ctrl_rollback(chain);
+ ret = uvc_ctrl_rollback(handle);
break;
}

@@ -990,6 +996,26 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
return uvc_video_enable(stream, 0);
}

+ case VIDIOC_SUBSCRIBE_EVENT:
+ {
+ struct v4l2_event_subscription *sub = arg;
+
+ switch (sub->type) {
+ case V4L2_EVENT_CTRL:
+ return v4l2_event_subscribe(&handle->vfh, sub, 0,
+ &uvc_ctrl_sub_ev_ops);
+ default:
+ return -EINVAL;
+ }
+ }
+
+ case VIDIOC_UNSUBSCRIBE_EVENT:
+ return v4l2_event_unsubscribe(&handle->vfh, arg);
+
+ case VIDIOC_DQEVENT:
+ return v4l2_event_dequeue(&handle->vfh, arg,
+ file->f_flags & O_NONBLOCK);
+
/* Analog video standards make no sense for digital cameras. */
case VIDIOC_ENUMSTD:
case VIDIOC_QUERYSTD:
diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 67f88d8..649a0bb 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -13,6 +13,8 @@
#include <linux/videodev2.h>
#include <media/media-device.h>
#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fh.h>
#include <media/videobuf2-core.h>

/* --------------------------------------------------------------------------
@@ -153,6 +155,7 @@ struct uvc_control_info {

struct uvc_control_mapping {
struct list_head list;
+ struct list_head ev_subs;

struct uvc_control_info *ctrl;

@@ -524,6 +527,7 @@ enum uvc_handle_state {
};

struct uvc_fh {
+ struct v4l2_fh vfh;
struct uvc_video_chain *chain;
struct uvc_streaming *stream;
enum uvc_handle_state state;
@@ -643,6 +647,8 @@ extern int uvc_status_suspend(struct uvc_device *dev);
extern int uvc_status_resume(struct uvc_device *dev);

/* Controls */
+extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;
+
extern int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
struct v4l2_queryctrl *v4l2_ctrl);
extern int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
@@ -655,14 +661,16 @@ extern void uvc_ctrl_cleanup_device(struct uvc_device *dev);
extern int uvc_ctrl_resume_device(struct uvc_device *dev);

extern int uvc_ctrl_begin(struct uvc_video_chain *chain);
-extern int __uvc_ctrl_commit(struct uvc_video_chain *chain, int rollback);
-static inline int uvc_ctrl_commit(struct uvc_video_chain *chain)
+extern int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
+ struct v4l2_ext_control *xctrls, int xctrls_count);
+static inline int uvc_ctrl_commit(struct uvc_fh *handle,
+ struct v4l2_ext_control *xctrls, int xctrls_count)
{
- return __uvc_ctrl_commit(chain, 0);
+ return __uvc_ctrl_commit(handle, 0, xctrls, xctrls_count);
}
-static inline int uvc_ctrl_rollback(struct uvc_video_chain *chain)
+static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
{
- return __uvc_ctrl_commit(chain, 1);
+ return __uvc_ctrl_commit(handle, 1, NULL, 0);
}

extern int uvc_ctrl_get(struct uvc_video_chain *chain,
--
1.7.9.3