doc-rst: linux_tv DocBook to reST migration (docs-next)
This is the restructuredText (reST) migration of the ``media``
DocBook-XML set from the linux_tv project.
Signed-off-by: Markus Heiser <markus.heiser@darmarIT.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/Documentation/linux_tv/media/v4l/vidioc-g-ctrl.rst b/Documentation/linux_tv/media/v4l/vidioc-g-ctrl.rst
new file mode 100644
index 0000000..6381d7c
--- /dev/null
+++ b/Documentation/linux_tv/media/v4l/vidioc-g-ctrl.rst
@@ -0,0 +1,114 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _vidioc-g-ctrl:
+
+**********************************
+ioctl VIDIOC_G_CTRL, VIDIOC_S_CTRL
+**********************************
+
+*man VIDIOC_G_CTRL(2)*
+
+VIDIOC_S_CTRL
+Get or set the value of a control
+
+
+Synopsis
+========
+
+.. c:function:: int ioctl( int fd, int request, struct v4l2_control *argp )
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :ref:`open() <func-open>`.
+
+``request``
+ VIDIOC_G_CTRL, VIDIOC_S_CTRL
+
+``argp``
+
+
+Description
+===========
+
+To get the current value of a control applications initialize the ``id``
+field of a struct :c:type:`struct v4l2_control` and call the
+``VIDIOC_G_CTRL`` ioctl with a pointer to this structure. To change the
+value of a control applications initialize the ``id`` and ``value``
+fields of a struct :c:type:`struct v4l2_control` and call the
+``VIDIOC_S_CTRL`` ioctl.
+
+When the ``id`` is invalid drivers return an EINVAL error code. When the
+``value`` is out of bounds drivers can choose to take the closest valid
+value or return an ERANGE error code, whatever seems more appropriate.
+However, ``VIDIOC_S_CTRL`` is a write-only ioctl, it does not return the
+actual new value. If the ``value`` is inappropriate for the control
+(e.g. if it refers to an unsupported menu index of a menu control), then
+EINVAL error code is returned as well.
+
+These ioctls work only with user controls. For other control classes the
+:ref:`VIDIOC_G_EXT_CTRLS <vidioc-g-ext-ctrls>`,
+:ref:`VIDIOC_S_EXT_CTRLS <vidioc-g-ext-ctrls>` or
+:ref:`VIDIOC_TRY_EXT_CTRLS <vidioc-g-ext-ctrls>` must be used.
+
+
+.. _v4l2-control:
+
+.. flat-table:: struct v4l2_control
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+
+ - .. row 1
+
+ - __u32
+
+ - ``id``
+
+ - Identifies the control, set by the application.
+
+ - .. row 2
+
+ - __s32
+
+ - ``value``
+
+ - New value or current value.
+
+
+
+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 struct :ref:`v4l2_control <v4l2-control>` ``id`` is invalid
+ or the ``value`` is inappropriate for the given control (i.e. if a
+ menu item is selected that is not supported by the driver according
+ to :ref:`VIDIOC_QUERYMENU <vidioc-queryctrl>`).
+
+ERANGE
+ The struct :ref:`v4l2_control <v4l2-control>` ``value`` is out of
+ bounds.
+
+EBUSY
+ The control is temporarily not changeable, possibly because another
+ applications took over control of the device function this control
+ belongs to.
+
+EACCES
+ Attempt to set a read-only control or to get a write-only control.
+
+
+.. ------------------------------------------------------------------------------
+.. This file was automatically converted from DocBook-XML with the dbxml
+.. library (https://github.com/return42/sphkerneldoc). The origin XML comes
+.. from the linux kernel, refer to:
+..
+.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
+.. ------------------------------------------------------------------------------