From 559f40fe0c5469d9080e3fa70638199c26cc460c Mon Sep 17 00:00:00 2001 From: Antti Palosaari Date: Fri, 20 Dec 2013 01:50:38 -0300 Subject: [PATCH] [media] DocBook: Software Defined Radio Interface Document V4L2 SDR interface. Cc: Hans Verkuil Signed-off-by: Antti Palosaari Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/media/v4l/compat.xml | 10 ++ Documentation/DocBook/media/v4l/dev-sdr.xml | 104 ++++++++++++++++++ Documentation/DocBook/media/v4l/io.xml | 6 + Documentation/DocBook/media/v4l/pixfmt.xml | 8 ++ Documentation/DocBook/media/v4l/v4l2.xml | 1 + .../DocBook/media/v4l/vidioc-g-fmt.xml | 7 ++ .../DocBook/media/v4l/vidioc-querycap.xml | 6 + 7 files changed, 142 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 c4cac6dbf9af..0b4db0e524ac 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2535,6 +2535,16 @@ fields changed from _s32 to _u32. +
+ V4L2 in Linux 3.15 + + + Added Software Defined Radio (SDR) Interface. + + + +
+
Relation of V4L2 to other Linux multimedia APIs diff --git a/Documentation/DocBook/media/v4l/dev-sdr.xml b/Documentation/DocBook/media/v4l/dev-sdr.xml new file mode 100644 index 000000000000..332b87f073cd --- /dev/null +++ b/Documentation/DocBook/media/v4l/dev-sdr.xml @@ -0,0 +1,104 @@ + Software Defined Radio Interface (SDR) + + +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. + + + +SDR devices are accessed through character device special files named +/dev/swradio0 to /dev/swradio255 +with major number 81 and dynamically allocated minor numbers 0 to 255. + + +
+ Querying Capabilities + + +Devices supporting the SDR receiver interface set the +V4L2_CAP_SDR_CAPTURE and +V4L2_CAP_TUNER flag in the +capabilities 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. + +
+ +
+ Supplemental Functions + + +SDR devices can support controls, and must +support the tuner ioctls. Tuner ioctls are used +for setting the ADC sampling rate (sampling frequency) and the possible RF tuner +frequency. + + + +The V4L2_TUNER_ADC tuner type is used for ADC tuners, and +the V4L2_TUNER_RF tuner type is used for RF tuners. The +tuner index 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. + + + +The &VIDIOC-S-HW-FREQ-SEEK; ioctl is not supported. + +
+ +
+ Data Format Negotiation + + +The SDR capture device uses the format ioctls to +select the capture format. Both the sampling resolution and the data streaming +format are bound to that selectable format. In addition to the basic +format ioctls, the &VIDIOC-ENUM-FMT; ioctl +must be supported as well. + + + +To use the format ioctls applications set the +type field of a &v4l2-format; to +V4L2_BUF_TYPE_SDR_CAPTURE and use the &v4l2-format-sdr; +sdr member of the fmt +union as needed per the desired operation. +Currently only the pixelformat field of +&v4l2-format-sdr; is used. The content of that field is the V4L2 fourcc code +of the data format. + + + + struct <structname>v4l2_format_sdr</structname> + + &cs-str; + + + __u32 + pixelformat + +The data format or type of compression, set by the application. This is a +little endian four character code. +V4L2 defines SDR formats in . + + + + __u8 + reserved[28] + This array is reserved for future extensions. +Drivers and applications must set it to zero. + + + +
+ + +An SDR device may support read/write +and/or streaming (memory mapping +or user pointer) I/O. + + +
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 2c4c068dde83..1fb11e8d2a26 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -1005,6 +1005,12 @@ should set this to 0. Buffer for video output overlay (OSD), see . + + V4L2_BUF_TYPE_SDR_CAPTURE + 11 + Buffer for Software Defined Radio (SDR), see . + diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml index 72d72bd67d0a..f586d3441b96 100644 --- a/Documentation/DocBook/media/v4l/pixfmt.xml +++ b/Documentation/DocBook/media/v4l/pixfmt.xml @@ -811,6 +811,14 @@ extended control V4L2_CID_MPEG_STREAM_TYPE, see
+
+ SDR Formats + + These formats are used for SDR Capture +interface only. + +
+
Reserved Format Identifiers diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index 6bf35328dcbf..e826d1d5df08 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -548,6 +548,7 @@ and discussions on the V4L mailing list.
&sub-dev-teletext;
&sub-dev-radio;
&sub-dev-rds;
+
&sub-dev-sdr;
&sub-dev-event;
&sub-dev-subdev;
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml index ee8f56e1bac0..f43f1a9285d6 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml @@ -169,6 +169,13 @@ capture and output devices. Sliced VBI capture or output parameters. See for details. Used by sliced VBI capture and output devices. + + + + &v4l2-format-sdr; + sdr + Definition of a data format, see +, used by SDR capture devices. diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml b/Documentation/DocBook/media/v4l/vidioc-querycap.xml index d5a3c97b206a..370d49d6fb64 100644 --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml @@ -294,6 +294,12 @@ interface. For more information on audio inputs and outputs see . + + + V4L2_CAP_SDR_CAPTURE + 0x00100000 + The device supports the +SDR Capture interface. V4L2_CAP_READWRITE -- 2.20.1