Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 103 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-frequency.rst b/Documentation/userspace-api/media/v4l/vidioc-g-frequency.rst
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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _VIDIOC_G_FREQUENCY:
+
+********************************************
+ioctl VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY
+********************************************
+
+Name
+====
+
+VIDIOC_G_FREQUENCY - VIDIOC_S_FREQUENCY - Get or set tuner or modulator radio frequency
+
+Synopsis
+========
+
+.. c:macro:: VIDIOC_G_FREQUENCY
+
+``int ioctl(int fd, VIDIOC_G_FREQUENCY, struct v4l2_frequency *argp)``
+
+.. c:macro:: VIDIOC_S_FREQUENCY
+
+``int ioctl(int fd, VIDIOC_S_FREQUENCY, const struct v4l2_frequency *argp)``
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :c:func:`open()`.
+
+``argp``
+    Pointer to struct :c:type:`v4l2_frequency`.
+
+Description
+===========
+
+To get the current tuner or modulator radio frequency applications set
+the ``tuner`` field of a struct
+:c:type:`v4l2_frequency` to the respective tuner or
+modulator number (only input devices have tuners, only output devices
+have modulators), zero out the ``reserved`` array and call the
+:ref:`VIDIOC_G_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl with a pointer to this structure. The
+driver stores the current frequency in the ``frequency`` field.
+
+To change the current tuner or modulator radio frequency applications
+initialize the ``tuner``, ``type`` and ``frequency`` fields, and the
+``reserved`` array of a struct :c:type:`v4l2_frequency`
+and call the :ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl with a pointer to this
+structure. When the requested frequency is not possible the driver
+assumes the closest possible value. However :ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` is a
+write-only ioctl, it does not return the actual new frequency.
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. c:type:: v4l2_frequency
+
+.. flat-table:: struct v4l2_frequency
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``tuner``
+      - The tuner or modulator index number. This is the same value as in
+	the struct :c:type:`v4l2_input` ``tuner`` field and
+	the struct :c:type:`v4l2_tuner` ``index`` field, or
+	the struct :c:type:`v4l2_output` ``modulator`` field
+	and the struct :c:type:`v4l2_modulator` ``index``
+	field.
+    * - __u32
+      - ``type``
+      - The tuner type. This is the same value as in the struct
+	:c:type:`v4l2_tuner` ``type`` field. The type must be
+	set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and
+	to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to
+	``V4L2_TUNER_RADIO`` for modulators (currently only radio
+	modulators are supported). See :c:type:`v4l2_tuner_type`
+    * - __u32
+      - ``frequency``
+      - Tuning frequency in units of 62.5 kHz, or if the struct
+	:c:type:`v4l2_tuner` or struct
+	:c:type:`v4l2_modulator` ``capability`` flag
+	``V4L2_TUNER_CAP_LOW`` is set, in units of 62.5 Hz. A 1 Hz unit is
+	used when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
+    * - __u32
+      - ``reserved``\ [8]
+      - Reserved for future extensions. Drivers and applications must set
+	the array to zero.
+
+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 ``tuner`` index is out of bounds or the value in the ``type``
+    field is wrong.
+
+EBUSY
+    A hardware seek is in progress.