summaryrefslogtreecommitdiffstats
path: root/Documentation/media/uapi/v4l/vidioc-g-input.rst
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-input.rst')
-rw-r--r--Documentation/media/uapi/v4l/vidioc-g-input.rst62
1 files changed, 62 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-input.rst b/Documentation/media/uapi/v4l/vidioc-g-input.rst
new file mode 100644
index 000000000000..29e22f6f8028
--- /dev/null
+++ b/Documentation/media/uapi/v4l/vidioc-g-input.rst
@@ -0,0 +1,62 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDIOC_G_INPUT:
+
+************************************
+ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT
+************************************
+
+Name
+====
+
+VIDIOC_G_INPUT - VIDIOC_S_INPUT - Query or select the current video input
+
+
+Synopsis
+========
+
+.. cpp:function:: int ioctl( int fd, int request, int *argp )
+
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :ref:`open() <func-open>`.
+
+``request``
+ VIDIOC_G_INPUT, VIDIOC_S_INPUT
+
+``argp``
+
+
+Description
+===========
+
+To query the current video input applications call the
+:ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer to an integer where the driver
+stores the number of the input, as in the struct
+:ref:`v4l2_input <v4l2-input>` ``index`` field. This ioctl will fail
+only when there are no video inputs, returning ``EINVAL``.
+
+To select a video input applications store the number of the desired
+input in an integer and call the :ref:`VIDIOC_S_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer
+to this integer. Side effects are possible. For example inputs may
+support different video standards, so the driver may implicitly switch
+the current standard. Because of these possible side effects
+applications must select an input before querying or negotiating any
+other parameters.
+
+Information about video inputs is available using the
+:ref:`VIDIOC_ENUMINPUT` ioctl.
+
+
+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.
+
+EINVAL
+ The number of the video input is out of bounds.