diff options
Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/dev-sdr.xml')
| -rw-r--r-- | kernel/Documentation/DocBook/media/v4l/dev-sdr.xml | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/dev-sdr.xml b/kernel/Documentation/DocBook/media/v4l/dev-sdr.xml index f8903568a..a659771f7 100644 --- a/kernel/Documentation/DocBook/media/v4l/dev-sdr.xml +++ b/kernel/Documentation/DocBook/media/v4l/dev-sdr.xml @@ -28,6 +28,16 @@ Devices supporting the SDR receiver interface set 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. + </para> + <para> +Devices supporting the SDR transmitter interface set the +<constant>V4L2_CAP_SDR_OUTPUT</constant> and +<constant>V4L2_CAP_MODULATOR</constant> flag in the +<structfield>capabilities</structfield> field of &v4l2-capability; +returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device has an +Digital to Analog Converter (DAC), which is a mandatory element for the SDR transmitter. + </para> + <para> At least one of the read/write, streaming or asynchronous I/O methods must be supported. </para> @@ -39,15 +49,16 @@ be supported. <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. +for setting the ADC/DAC sampling rate (sampling frequency) and the possible +radio frequency (RF). </para> <para> -The <constant>V4L2_TUNER_ADC</constant> tuner type is used for ADC tuners, and -the <constant>V4L2_TUNER_RF</constant> 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 <constant>V4L2_TUNER_SDR</constant> tuner type is used for setting SDR +device ADC/DAC frequency, and the <constant>V4L2_TUNER_RF</constant> +tuner type is used for setting radio frequency. +The tuner index of the RF tuner (if any) must always follow the SDR tuner index. +Normally the SDR tuner is #0 and the RF tuner is #1. </para> <para> @@ -59,9 +70,9 @@ The &VIDIOC-S-HW-FREQ-SEEK; ioctl is not supported. <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 the basic +The SDR device uses the <link linkend="format">format</link> ioctls to +select the capture and output format. Both the sampling resolution and the data +streaming format are bound to that selectable format. In addition to the basic <link linkend="format">format</link> ioctls, the &VIDIOC-ENUM-FMT; ioctl must be supported as well. </para> @@ -69,7 +80,8 @@ must be supported as well. <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-sdr-format; +<constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant> or +<constant>V4L2_BUF_TYPE_SDR_OUTPUT</constant> and use the &v4l2-sdr-format; <structfield>sdr</structfield> member of the <structfield>fmt</structfield> union as needed per the desired operation. Currently there is two fields, <structfield>pixelformat</structfield> and |