diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-queryctrl.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-queryctrl.rst | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst index 0f27e712eec9..4342aceddd57 100644 --- a/Documentation/media/uapi/v4l/vidioc-queryctrl.rst +++ b/Documentation/media/uapi/v4l/vidioc-queryctrl.rst @@ -82,10 +82,12 @@ fills the rest of the structure or returns an ``EINVAL`` error code when the ``id`` or ``index`` is invalid. Menu items are enumerated by calling ``VIDIOC_QUERYMENU`` with successive ``index`` values from struct :ref:`v4l2_queryctrl <v4l2-queryctrl>` ``minimum`` to ``maximum``, -inclusive. Note that it is possible for ``VIDIOC_QUERYMENU`` to return -an ``EINVAL`` error code for some indices between ``minimum`` and -``maximum``. In that case that particular menu item is not supported by -this driver. Also note that the ``minimum`` value is not necessarily 0. +inclusive. + +.. note:: It is possible for ``VIDIOC_QUERYMENU`` to return + an ``EINVAL`` error code for some indices between ``minimum`` and + ``maximum``. In that case that particular menu item is not supported by + this driver. Also note that the ``minimum`` value is not necessarily 0. See also the examples in :ref:`control`. @@ -184,9 +186,10 @@ See also the examples in :ref:`control`. - The default value of a ``V4L2_CTRL_TYPE_INTEGER``, ``_BOOLEAN``, ``_BITMASK``, ``_MENU`` or ``_INTEGER_MENU`` control. Not valid - for other types of controls. Note that drivers reset controls to - their default value only when the driver is first loaded, never - afterwards. + for other types of controls. + + .. note:: Drivers reset controls to their default value only when + the driver is first loaded, never afterwards. - .. row 8 @@ -301,9 +304,10 @@ See also the examples in :ref:`control`. - The default value of a ``V4L2_CTRL_TYPE_INTEGER``, ``_INTEGER64``, ``_BOOLEAN``, ``_BITMASK``, ``_MENU``, ``_INTEGER_MENU``, ``_U8`` - or ``_U16`` control. Not valid for other types of controls. Note - that drivers reset controls to their default value only when the - driver is first loaded, never afterwards. + or ``_U16`` control. Not valid for other types of controls. + + .. note:: Drivers reset controls to their default value only when + the driver is first loaded, never afterwards. - .. row 8 @@ -722,11 +726,12 @@ See also the examples in :ref:`control`. control changes continuously. A typical example would be the current gain value if the device is in auto-gain mode. In such a case the hardware calculates the gain value based on the lighting - conditions which can change over time. Note that setting a new - value for a volatile control will have no effect and no - ``V4L2_EVENT_CTRL_CH_VALUE`` will be sent, unless the - ``V4L2_CTRL_FLAG_EXECUTE_ON_WRITE`` flag (see below) is also set. - Otherwise the new value will just be ignored. + conditions which can change over time. + + .. note:: Setting a new value for a volatile control will have no + effect and no ``V4L2_EVENT_CTRL_CH_VALUE`` will be sent, unless + the ``V4L2_CTRL_FLAG_EXECUTE_ON_WRITE`` flag (see below) is + also set. Otherwise the new value will just be ignored. - .. row 9 |
