diff options
Diffstat (limited to 'Documentation/DocBook')
| -rw-r--r-- | Documentation/DocBook/media/v4l/v4l2.xml | 10 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml | 22 |
2 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index 7e61643358de..42e626d6c936 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -152,6 +152,16 @@ structs, ioctls) must be noted in more detail in the history chapter (compat.xml), along with the possible impact on existing drivers and applications. --> <revision> + <revnumber>4.5</revnumber> + <date>2015-10-29</date> + <authorinitials>rr</authorinitials> + <revremark>Extend vidioc-g-ext-ctrls;. Replace ctrl_class with a new +union with ctrl_class and which. Which is used to select the current value of +the control or the default value. + </revremark> + </revision> + + <revision> <revnumber>4.4</revnumber> <date>2015-05-26</date> <authorinitials>ap</authorinitials> diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml index 47f9fee91442..eb82f7e7d06b 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml @@ -223,7 +223,12 @@ Valid if <constant>V4L2_CTRL_FLAG_HAS_PAYLOAD</constant> is set for this control <tgroup cols="3"> &cs-str; <tbody valign="top"> + <row> + <entry>union</entry> + <entry>(anonymous)</entry> + </row> <row> + <entry></entry> <entry>__u32</entry> <entry><structfield>ctrl_class</structfield></entry> <entry>The control class to which all controls belong, see @@ -235,6 +240,23 @@ with a <structfield>count</structfield> of 0. If that succeeds, then the driver supports this feature.</entry> </row> <row> + <entry></entry> + <entry>__u32</entry> + <entry><structfield>which</structfield></entry> + <entry><para>Which value of the control to get/set/try. <constant>V4L2_CTRL_WHICH_CUR_VAL</constant> +will return the current value of the control and <constant>V4L2_CTRL_WHICH_DEF_VAL</constant> will +return the default value of the control. Please note that you can only get the default value of the +control, you cannot set or try it.</para> +<para>For backwards compatibility you can also use a control class here (see +<xref linkend="ctrl-class" />). In that case all controls have to belong to that +control class. This usage is deprecated, instead just use <constant>V4L2_CTRL_WHICH_CUR_VAL</constant>. +There are some very old drivers that do not yet support <constant>V4L2_CTRL_WHICH_CUR_VAL</constant> +and that require a control class here. You can test for such drivers by setting ctrl_class to +<constant>V4L2_CTRL_WHICH_CUR_VAL</constant> and calling VIDIOC_TRY_EXT_CTRLS with a count of 0. +If that fails, then the driver does not support <constant>V4L2_CTRL_WHICH_CUR_VAL</constant>.</para> +</entry> + </row> + <row> <entry>__u32</entry> <entry><structfield>count</structfield></entry> <entry>The number of controls in the controls array. May |