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diff --git a/Documentation/media/uapi/v4l/dev-rds.rst b/Documentation/media/uapi/v4l/dev-rds.rst deleted file mode 100644 index 64a724ef58f5..000000000000 --- a/Documentation/media/uapi/v4l/dev-rds.rst +++ /dev/null @@ -1,191 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _rds: - -************* -RDS Interface -************* - -The Radio Data System transmits supplementary information in binary -format, for example the station name or travel information, on an -inaudible audio subcarrier of a radio program. This interface is aimed -at devices capable of receiving and/or transmitting RDS information. - -For more information see the core RDS standard :ref:`iec62106` and the -RBDS standard :ref:`nrsc4`. - -.. note:: - - Note that the RBDS standard as is used in the USA is almost - identical to the RDS standard. Any RDS decoder/encoder can also handle - RBDS. Only some of the fields have slightly different meanings. See the - RBDS standard for more information. - -The RBDS standard also specifies support for MMBS (Modified Mobile -Search). This is a proprietary format which seems to be discontinued. -The RDS interface does not support this format. Should support for MMBS -(or the so-called 'E blocks' in general) be needed, then please contact -the linux-media mailing list: -`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__. - - -Querying Capabilities -===================== - -Devices supporting the RDS capturing API set the -``V4L2_CAP_RDS_CAPTURE`` flag in the ``capabilities`` field of struct -:c:type:`v4l2_capability` returned by the -:ref:`VIDIOC_QUERYCAP` ioctl. Any tuner that -supports RDS will set the ``V4L2_TUNER_CAP_RDS`` flag in the -``capability`` field of struct :c:type:`v4l2_tuner`. If the -driver only passes RDS blocks without interpreting the data the -``V4L2_TUNER_CAP_RDS_BLOCK_IO`` flag has to be set, see -:ref:`Reading RDS data <reading-rds-data>`. For future use the flag -``V4L2_TUNER_CAP_RDS_CONTROLS`` has also been defined. However, a driver -for a radio tuner with this capability does not yet exist, so if you are -planning to write such a driver you should discuss this on the -linux-media mailing list: -`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__. - -Whether an RDS signal is present can be detected by looking at the -``rxsubchans`` field of struct :c:type:`v4l2_tuner`: the -``V4L2_TUNER_SUB_RDS`` will be set if RDS data was detected. - -Devices supporting the RDS output API set the ``V4L2_CAP_RDS_OUTPUT`` -flag in the ``capabilities`` field of struct -:c:type:`v4l2_capability` returned by the -:ref:`VIDIOC_QUERYCAP` ioctl. Any modulator that -supports RDS will set the ``V4L2_TUNER_CAP_RDS`` flag in the -``capability`` field of struct -:c:type:`v4l2_modulator`. In order to enable the RDS -transmission one must set the ``V4L2_TUNER_SUB_RDS`` bit in the -``txsubchans`` field of struct -:c:type:`v4l2_modulator`. If the driver only passes RDS -blocks without interpreting the data the ``V4L2_TUNER_CAP_RDS_BLOCK_IO`` -flag has to be set. If the tuner is capable of handling RDS entities -like program identification codes and radio text, the flag -``V4L2_TUNER_CAP_RDS_CONTROLS`` should be set, see -:ref:`Writing RDS data <writing-rds-data>` and -:ref:`FM Transmitter Control Reference <fm-tx-controls>`. - - -.. _reading-rds-data: - -Reading RDS data -================ - -RDS data can be read from the radio device with the -:ref:`read() <func-read>` function. The data is packed in groups of -three bytes. - - -.. _writing-rds-data: - -Writing RDS data -================ - -RDS data can be written to the radio device with the -:ref:`write() <func-write>` function. The data is packed in groups of -three bytes, as follows: - - -RDS datastructures -================== - - -.. c:type:: v4l2_rds_data - -.. tabularcolumns:: |p{2.5cm}|p{2.5cm}|p{12.5cm}| - -.. flat-table:: struct v4l2_rds_data - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 5 - - * - __u8 - - ``lsb`` - - Least Significant Byte of RDS Block - * - __u8 - - ``msb`` - - Most Significant Byte of RDS Block - * - __u8 - - ``block`` - - Block description - - - -.. _v4l2-rds-block: - -.. tabularcolumns:: |p{2.9cm}|p{14.6cm}| - -.. flat-table:: Block description - :header-rows: 0 - :stub-columns: 0 - :widths: 1 5 - - * - Bits 0-2 - - Block (aka offset) of the received data. - * - Bits 3-5 - - Deprecated. Currently identical to bits 0-2. Do not use these - bits. - * - Bit 6 - - Corrected bit. Indicates that an error was corrected for this data - block. - * - Bit 7 - - Error bit. Indicates that an uncorrectable error occurred during - reception of this block. - - - -.. _v4l2-rds-block-codes: - -.. tabularcolumns:: |p{6.4cm}|p{2.0cm}|p{1.2cm}|p{7.9cm}| - -.. flat-table:: Block defines - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 1 5 - - * - V4L2_RDS_BLOCK_MSK - - - - 7 - - Mask for bits 0-2 to get the block ID. - * - V4L2_RDS_BLOCK_A - - - - 0 - - Block A. - * - V4L2_RDS_BLOCK_B - - - - 1 - - Block B. - * - V4L2_RDS_BLOCK_C - - - - 2 - - Block C. - * - V4L2_RDS_BLOCK_D - - - - 3 - - Block D. - * - V4L2_RDS_BLOCK_C_ALT - - - - 4 - - Block C'. - * - V4L2_RDS_BLOCK_INVALID - - read-only - - 7 - - An invalid block. - * - V4L2_RDS_BLOCK_CORRECTED - - read-only - - 0x40 - - A bit error was detected but corrected. - * - V4L2_RDS_BLOCK_ERROR - - read-only - - 0x80 - - An uncorrectable error occurred. |