summaryrefslogtreecommitdiffstats
path: root/Documentation/media/uapi/dvb/video-get-event.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/media/uapi/dvb/video-get-event.rst')
-rw-r--r--Documentation/media/uapi/dvb/video-get-event.rst88
1 files changed, 88 insertions, 0 deletions
diff --git a/Documentation/media/uapi/dvb/video-get-event.rst b/Documentation/media/uapi/dvb/video-get-event.rst
new file mode 100644
index 000000000000..a1484a226518
--- /dev/null
+++ b/Documentation/media/uapi/dvb/video-get-event.rst
@@ -0,0 +1,88 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDEO_GET_EVENT:
+
+===============
+VIDEO_GET_EVENT
+===============
+
+Name
+----
+
+VIDEO_GET_EVENT
+
+
+Synopsis
+--------
+
+.. cpp:function:: int ioctl(fd, int request = VIDEO_GET_EVENT, struct video_event *ev)
+
+
+Arguments
+---------
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+
+
+ - .. row 1
+
+ - int fd
+
+ - File descriptor returned by a previous call to open().
+
+ - .. row 2
+
+ - int request
+
+ - Equals VIDEO_GET_EVENT for this command.
+
+ - .. row 3
+
+ - struct video_event \*ev
+
+ - Points to the location where the event, if any, is to be stored.
+
+
+Description
+-----------
+
+This ioctl is for DVB devices only. To get events from a V4L2 decoder
+use the V4L2 :ref:`VIDIOC_DQEVENT` ioctl instead.
+
+This ioctl call returns an event of type video_event if available. If
+an event is not available, the behavior depends on whether the device is
+in blocking or non-blocking mode. In the latter case, the call fails
+immediately with errno set to ``EWOULDBLOCK``. In the former case, the call
+blocks until an event becomes available. The standard Linux poll()
+and/or select() system calls can be used with the device file descriptor
+to watch for new events. For select(), the file descriptor should be
+included in the exceptfds argument, and for poll(), POLLPRI should be
+specified as the wake-up condition. Read-only permissions are sufficient
+for this ioctl call.
+
+
+Return Value
+------------
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+.. flat-table::
+ :header-rows: 0
+ :stub-columns: 0
+
+
+ - .. row 1
+
+ - ``EWOULDBLOCK``
+
+ - There is no event pending, and the device is in non-blocking mode.
+
+ - .. row 2
+
+ - ``EOVERFLOW``
+
+ - Overflow in event queue - one or more events were lost.