diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml | 68 |
1 files changed, 57 insertions, 11 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml index 407dfceb71f0..3dd1bec6d3c7 100644 --- a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml +++ b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml @@ -52,11 +52,26 @@ <para>Start a hardware frequency seek from the current frequency. To do this applications initialize the <structfield>tuner</structfield>, <structfield>type</structfield>, <structfield>seek_upward</structfield>, -<structfield>spacing</structfield> and -<structfield>wrap_around</structfield> fields, and zero out the -<structfield>reserved</structfield> array of a &v4l2-hw-freq-seek; and -call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> ioctl with a pointer -to this structure.</para> +<structfield>wrap_around</structfield>, <structfield>spacing</structfield>, +<structfield>rangelow</structfield> and <structfield>rangehigh</structfield> +fields, and zero out the <structfield>reserved</structfield> array of a +&v4l2-hw-freq-seek; and call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> +ioctl with a pointer to this structure.</para> + + <para>The <structfield>rangelow</structfield> and +<structfield>rangehigh</structfield> fields can be set to a non-zero value to +tell the driver to search a specific band. If the &v4l2-tuner; +<structfield>capability</structfield> field has the +<constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag set, these values +must fall within one of the bands returned by &VIDIOC-ENUM-FREQ-BANDS;. If +the <constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag is not set, +then these values must exactly match those of one of the bands returned by +&VIDIOC-ENUM-FREQ-BANDS;. If the current frequency of the tuner does not fall +within the selected band it will be clamped to fit in the band before the +seek is started.</para> + + <para>If an error is returned, then the original frequency will + be restored.</para> <para>This ioctl is supported if the <constant>V4L2_CAP_HW_FREQ_SEEK</constant> capability is set.</para> @@ -87,7 +102,10 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry> <row> <entry>__u32</entry> <entry><structfield>wrap_around</structfield></entry> - <entry>If non-zero, wrap around when at the end of the frequency range, else stop seeking.</entry> + <entry>If non-zero, wrap around when at the end of the frequency range, else stop seeking. + The &v4l2-tuner; <structfield>capability</structfield> field will tell you what the + hardware supports. + </entry> </row> <row> <entry>__u32</entry> @@ -96,7 +114,27 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry> </row> <row> <entry>__u32</entry> - <entry><structfield>reserved</structfield>[7]</entry> + <entry><structfield>rangelow</structfield></entry> + <entry>If non-zero, the lowest tunable frequency of the band to +search in units of 62.5 kHz, or if the &v4l2-tuner; +<structfield>capability</structfield> field has the +<constant>V4L2_TUNER_CAP_LOW</constant> flag set, in units of 62.5 Hz. +If <structfield>rangelow</structfield> is zero a reasonable default value +is used.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>rangehigh</structfield></entry> + <entry>If non-zero, the highest tunable frequency of the band to +search in units of 62.5 kHz, or if the &v4l2-tuner; +<structfield>capability</structfield> field has the +<constant>V4L2_TUNER_CAP_LOW</constant> flag set, in units of 62.5 Hz. +If <structfield>rangehigh</structfield> is zero a reasonable default value +is used.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[5]</entry> <entry>Reserved for future extensions. Applications must set the array to zero.</entry> </row> @@ -113,14 +151,22 @@ field and the &v4l2-tuner; <structfield>index</structfield> field.</entry> <term><errorcode>EINVAL</errorcode></term> <listitem> <para>The <structfield>tuner</structfield> index is out of -bounds, the wrap_around value is not supported or the value in the <structfield>type</structfield> field is -wrong.</para> +bounds, the <structfield>wrap_around</structfield> value is not supported or +one of the values in the <structfield>type</structfield>, +<structfield>rangelow</structfield> or <structfield>rangehigh</structfield> +fields is wrong.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><errorcode>ENODATA</errorcode></term> + <listitem> + <para>The hardware seek found no channels.</para> </listitem> </varlistentry> <varlistentry> - <term><errorcode>EAGAIN</errorcode></term> + <term><errorcode>EBUSY</errorcode></term> <listitem> - <para>The ioctl timed-out. Try again.</para> + <para>Another hardware seek is already in progress.</para> </listitem> </varlistentry> </variablelist> |
