From 50121317c2035c017d62c8ec24f84b91ef8d4de2 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Thu, 5 Jul 2012 06:54:38 -0300 Subject: [media] v4l2 spec: add VIDIOC_ENUM_FREQ_BANDS documentation Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- .../DocBook/media/v4l/vidioc-enum-freq-bands.xml | 179 +++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml (limited to 'Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml') diff --git a/Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml b/Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml new file mode 100644 index 000000000000..6541ba0175ed --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-enum-freq-bands.xml @@ -0,0 +1,179 @@ + + + ioctl VIDIOC_ENUM_FREQ_BANDS + &manvol; + + + + VIDIOC_ENUM_FREQ_BANDS + Enumerate supported frequency bands + + + + + + int ioctl + int fd + int request + struct v4l2_frequency_band +*argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_ENUM_FREQ_BANDS + + + + argp + + + + + + + + + Description + + + Experimental + This is an experimental + interface and may change in the future. + + + Enumerates the frequency bands that a tuner or modulator supports. +To do this applications initialize the tuner, +type and index fields, +and zero out the reserved array of a &v4l2-frequency-band; and +call the VIDIOC_ENUM_FREQ_BANDS ioctl with a pointer +to this structure. + + This ioctl is supported if the V4L2_TUNER_CAP_FREQ_BANDS capability + of the corresponding tuner/modulator is set. + + + struct <structname>v4l2_frequency_band</structname> + + &cs-str; + + + __u32 + tuner + The tuner or modulator index number. This is the +same value as in the &v4l2-input; tuner +field and the &v4l2-tuner; index field, or +the &v4l2-output; modulator field and the +&v4l2-modulator; index field. + + + __u32 + type + The tuner type. This is the same value as in the +&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 + + + __u32 + index + Identifies the frequency band, set by the application. + + + __u32 + capability + The tuner/modulator capability flags for +this frequency band, see . The V4L2_TUNER_CAP_LOW +capability must be the same for all frequency bands of the selected tuner/modulator. +So either all bands have that capability set, or none of them have that capability. + + + __u32 + rangelow + The lowest tunable frequency in +units of 62.5 kHz, or if the capability +flag V4L2_TUNER_CAP_LOW is set, in units of 62.5 +Hz, for this frequency band. + + + __u32 + rangehigh + The highest tunable frequency in +units of 62.5 kHz, or if the capability +flag V4L2_TUNER_CAP_LOW is set, in units of 62.5 +Hz, for this frequency band. + + + __u32 + modulation + The supported modulation systems of this frequency band. + See . Note that currently only one + modulation system per frequency band is supported. More work will need to + be done if multiple modulation systems are possible. Contact the + linux-media mailing list (&v4l-ml;) if you need that functionality. + + + __u32 + reserved[9] + Reserved for future extensions. Applications and drivers + must set the array to zero. + + + +
+ + + Band Modulation Systems + + &cs-def; + + + V4L2_BAND_MODULATION_VSB + 0x02 + Vestigial Sideband modulation, used for analog TV. + + + V4L2_BAND_MODULATION_FM + 0x04 + Frequency Modulation, commonly used for analog radio. + + + V4L2_BAND_MODULATION_AM + 0x08 + Amplitude Modulation, commonly used for analog radio. + + + +
+ + + + &return-value; + + + + EINVAL + + The tuner or index +is out of bounds or the type field is wrong. + + + + + -- cgit