From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- .../DocBook/media/v4l/vidioc-g-frequency.xml | 148 +++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 Documentation/DocBook/media/v4l/vidioc-g-frequency.xml (limited to 'Documentation/DocBook/media/v4l/vidioc-g-frequency.xml') diff --git a/Documentation/DocBook/media/v4l/vidioc-g-frequency.xml b/Documentation/DocBook/media/v4l/vidioc-g-frequency.xml new file mode 100644 index 000000000..d1034fb61 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-g-frequency.xml @@ -0,0 +1,148 @@ + + + ioctl VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY + &manvol; + + + + VIDIOC_G_FREQUENCY + VIDIOC_S_FREQUENCY + Get or set tuner or modulator radio +frequency + + + + + + int ioctl + int fd + int request + struct v4l2_frequency +*argp + + + + + int ioctl + int fd + int request + const struct v4l2_frequency +*argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY + + + + argp + + + + + + + + + Description + + To get the current tuner or modulator radio frequency +applications set the tuner field of a +&v4l2-frequency; to the respective tuner or modulator number (only +input devices have tuners, only output devices have modulators), zero +out the reserved array and +call the VIDIOC_G_FREQUENCY ioctl with a pointer +to this structure. The driver stores the current frequency in the +frequency field. + + To change the current tuner or modulator radio frequency +applications initialize the tuner, +type and +frequency fields, and the +reserved array of a &v4l2-frequency; and +call the VIDIOC_S_FREQUENCY ioctl with a pointer +to this structure. When the requested frequency is not possible the +driver assumes the closest possible value. However +VIDIOC_S_FREQUENCY is a write-only ioctl, it does +not return the actual new frequency. + + + struct <structname>v4l2_frequency</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 + frequency + Tuning frequency in units of 62.5 kHz, or if the +&v4l2-tuner; or &v4l2-modulator; capability flag +V4L2_TUNER_CAP_LOW is set, in units of 62.5 +Hz. A 1 Hz unit is used when the capability flag +V4L2_TUNER_CAP_1HZ is set. + + + __u32 + reserved[8] + Reserved for future extensions. Drivers and + applications must set the array to zero. + + + +
+
+ + + &return-value; + + + + EINVAL + + The tuner index is out of +bounds or the value in the type field is +wrong. + + + + EBUSY + + A hardware seek is in progress. + + + + +
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