More small fixes: On 12/29/2013 05:04 AM, Antti Palosaari wrote: > Document V4L2 SDR interface. > > Cc: Hans Verkuil <hverkuil@xxxxxxxxx> > Signed-off-by: Antti Palosaari <crope@xxxxxx> > --- > Documentation/DocBook/media/v4l/compat.xml | 10 ++ > Documentation/DocBook/media/v4l/dev-sdr.xml | 107 +++++++++++++++++++++ > Documentation/DocBook/media/v4l/io.xml | 6 ++ > Documentation/DocBook/media/v4l/v4l2.xml | 1 + > Documentation/DocBook/media/v4l/vidioc-g-fmt.xml | 7 ++ > .../DocBook/media/v4l/vidioc-querycap.xml | 6 ++ > 6 files changed, 137 insertions(+) > create mode 100644 Documentation/DocBook/media/v4l/dev-sdr.xml > > diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml > index 0c7195e..85fb864 100644 > --- a/Documentation/DocBook/media/v4l/compat.xml > +++ b/Documentation/DocBook/media/v4l/compat.xml > @@ -2523,6 +2523,16 @@ that used it. It was originally scheduled for removal in 2.6.35. > </orderedlist> > </section> > > + <section> > + <title>V4L2 in Linux 3.14</title> > + <orderedlist> > + <listitem> > + <para>Added Software Defined Radio (SDR) Interface. > + </para> > + </listitem> > + </orderedlist> > + </section> > + > <section id="other"> > <title>Relation of V4L2 to other Linux multimedia APIs</title> > > diff --git a/Documentation/DocBook/media/v4l/dev-sdr.xml b/Documentation/DocBook/media/v4l/dev-sdr.xml > new file mode 100644 > index 0000000..db4859f > --- /dev/null > +++ b/Documentation/DocBook/media/v4l/dev-sdr.xml > @@ -0,0 +1,107 @@ > + <title>Software Defined Radio Interface (SDR)</title> > + > + <para> > +SDR is an abbreviation of Software Defined Radio, the radio device > +which uses application software for modulation or demodulation. This interface > +is intended for controlling and data streaming of such devices. > + </para> > + > + <para> > +SDR devices are accessed through character device special files named > +<filename>/dev/swradio0</filename> to <filename>/dev/swradio255</filename> > +with major number 81 and dynamically allocated minor numbers 0 to 255. > + </para> > + > + <section> > + <title>Querying Capabilities</title> > + > + <para> > +Devices supporting the SDR receiver interface set the > +<constant>V4L2_CAP_SDR_CAPTURE</constant> and > +<constant>V4L2_CAP_TUNER</constant> flag in the > +<structfield>capabilities</structfield> field of &v4l2-capability; > +returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device has an > +Analog to Digital Converter (ADC), which is a mandatory element for the SDR receiver. > +At least one of the read/write, streaming or asynchronous I/O methods must > +be supported. > + </para> > + </section> > + > + <section> > + <title>Supplemental Functions</title> > + > + <para> > +SDR devices can support <link linkend="control">controls</link>, and must > +support the <link linkend="tuner">tuner</link> ioctls. Tuner ioctls are used > +for setting the ADC sampling rate (sampling frequency) and the possible RF tuner > +frequency. > + </para> > + > + <para> > +The <constant>V4L2_TUNER_ADC</constant> tuner type is used for ADC tuners, and > +the <constant>V4L2_TUNER_RF</constant> is used for RF tuners. The tuner index s/is used/tuner type is used/ > +of the RF tuner (if any) must always follow the ADC tuner index. Normally the > +ADC tuner is #0 and the RF tuner is #1. > + </para> > + > + <para> > +The &VIDIOC-S-HW-FREQ-SEEK; ioctl is not supported. > + </para> > + </section> > + > + <section> > + <title>Data Format Negotiation</title> > + > + <para> > +The SDR capture device uses the <link linkend="format">format</link> ioctls to > +select the capture format. Both the sampling resolution and the data streaming > +format are bound to that selectable format. In addition to basic s/to basic/to the basic/ > +<link linkend="format">format</link> ioctls, the &VIDIOC-ENUM-FMT; ioctl > +must be supported too. s/too/as well/ > + </para> > + > + <para> > +To use the <link linkend="format">format</link> ioctls applications set the > +<structfield>type</structfield> field of a &v4l2-format; to > +<constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant> and use the &v4l2-format-sdr; > +<structfield>sdr</structfield> member of the <structfield>fmt</structfield> > +union as needed per the desired operation. > +Currently only the <structfield>pixelformat</structfield> field of > +&v4l2-format-sdr; is used. The content of that field is the V4L2 fourcc code > +of the data format. > + </para> > + > + <table pgwide="1" frame="none" id="v4l2-format-sdr"> > + <title>struct <structname>v4l2_format_sdr</structname></title> > + <tgroup cols="3"> > + &cs-str; > + <tbody valign="top"> > + <row> > + <entry>__u32</entry> > + <entry><structfield>pixelformat</structfield></entry> > + <entry> > +The pixel format or type of compression, set by the > +application. This is a little endian > +<link linkend="v4l2-fourcc">four character code</link>. V4L2 defines > +standard RGB formats in <xref linkend="rgb-formats" />, YUV formats in > +<xref linkend="yuv-formats" />, and reserved codes in > +<xref linkend="reserved-formats" /> Instead of pointing to the RGB/YUV/Reserved codes (which makes no sense for SDR) you need to point to a new section where the SDR fourcc formats are described. > + </entry> > + </row> > + <row> > + <entry>__u8</entry> > + <entry><structfield>reserved[28]</structfield></entry> > + <entry>This array is reserved for future extensions. > +Drivers and applications must set it to zero.</entry> > + </row> > + </tbody> > + </tgroup> > + </table> > + > + <para> > +An SDR device may support <link linkend="rw">read/write</link> > +and/or streaming (<link linkend="mmap">memory mapping</link> > +or <link linkend="userp">user pointer</link>) I/O. > + </para> > + > + </section> > diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > index 2c4c068..1fb11e8 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -1005,6 +1005,12 @@ should set this to 0.</entry> > <entry>Buffer for video output overlay (OSD), see <xref > linkend="osd" />.</entry> > </row> > + <row> > + <entry><constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant></entry> > + <entry>11</entry> > + <entry>Buffer for Software Defined Radio (SDR), see <xref > + linkend="sdr" />.</entry> > + </row> > </tbody> > </tgroup> > </table> > diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml > index 8469fe1..a27fcae 100644 > --- a/Documentation/DocBook/media/v4l/v4l2.xml > +++ b/Documentation/DocBook/media/v4l/v4l2.xml > @@ -529,6 +529,7 @@ and discussions on the V4L mailing list.</revremark> > <section id="ttx"> &sub-dev-teletext; </section> > <section id="radio"> &sub-dev-radio; </section> > <section id="rds"> &sub-dev-rds; </section> > + <section id="sdr"> &sub-dev-sdr; </section> > <section id="event"> &sub-dev-event; </section> > <section id="subdev"> &sub-dev-subdev; </section> > </chapter> > diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > index ee8f56e..ffed137 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > @@ -172,6 +172,13 @@ capture and output devices.</entry> > </row> > <row> > <entry></entry> > + <entry>&v4l2-format-sdr;</entry> > + <entry><structfield>sdr</structfield></entry> > + <entry>Definition of an data format, see > +<xref linkend="pixfmt" />, used by SDR capture devices.</entry> > + </row> > + <row> > + <entry></entry> > <entry>__u8</entry> > <entry><structfield>raw_data</structfield>[200]</entry> > <entry>Place holder for future extensions.</entry> > diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml b/Documentation/DocBook/media/v4l/vidioc-querycap.xml > index d5a3c97..370d49d 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml > @@ -296,6 +296,12 @@ modulator programming see > <xref linkend="tuner" />.</entry> > </row> > <row> > + <entry><constant>V4L2_CAP_SDR_CAPTURE</constant></entry> > + <entry>0x00100000</entry> > + <entry>The device supports the > +<link linkend="sdr">SDR Capture</link> interface.</entry> > + </row> > + <row> > <entry><constant>V4L2_CAP_READWRITE</constant></entry> > <entry>0x01000000</entry> > <entry>The device supports the <link > Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
