v4l2-spec: update for new modulator and rds encoder caps.

From: Hans Verkuil <hverkuil@xs4all.nl>

Document the radio modulator and RDS encoder API.

Priority: normal

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

1 files changed, 8 insertions, 6 deletions

diff --git a/v4l2-spec/dev-radio.sgml b/v4l2-spec/dev-radio.sgml
index ae8367219..4d521d2a8 100644
--- a/v4l2-spec/dev-radio.sgml
+++ b/v4l2-spec/dev-radio.sgml
@@ -1,7 +1,7 @@
   <title>Radio Interface</title>
 
   <para>This interface is intended for AM and FM (analog) radio
-receivers.</para>
+receivers and transmitters.</para>
 
   <para>Conventionally V4L2 radio devices are accessed through
 character device special files named <filename>/dev/radio</filename>
@@ -14,7 +14,8 @@ numbers 64 to 127.</para>
 
     <para>Devices supporting the radio interface set the
 <constant>V4L2_CAP_RADIO</constant> and
-<constant>V4L2_CAP_TUNER</constant> flag in the
+<constant>V4L2_CAP_TUNER</constant> or
+<constant>V4L2_CAP_MODULATOR</constant> flag in the
 <structfield>capabilities</structfield> field of &v4l2-capability;
 returned by the &VIDIOC-QUERYCAP; ioctl. Other combinations of
 capability flags are reserved for future extensions.</para>
@@ -25,7 +26,7 @@ capability flags are reserved for future extensions.</para>
 
     <para>Radio devices can support <link
 linkend="control">controls</link>, and must support the <link
-linkend="tuner">tuner</link> ioctls.</para>
+linkend="tuner">tuner or modulator</link> ioctls.</para>
 
     <para>They do not support the video input or output, audio input
 or output, video standard, cropping and scaling, compression and
@@ -38,11 +39,12 @@ methods are reserved for future extensions.</para>
 
     <para>Radio devices may have a couple audio controls (as discussed
 in <xref linkend="control">) such as a volume control, possibly custom
-controls. Further all radio devices have one tuner (these are
+controls. Further all radio devices have one tuner or modulator (these are
 discussed in <xref linkend="tuner">) with index number zero to select
 the radio frequency and to determine if a monaural or FM stereo
-program is received. Drivers switch automatically between AM and FM
-depending on the selected frequency. The &VIDIOC-G-TUNER; ioctl
+program is received/emitted. Drivers switch automatically between AM and FM
+depending on the selected frequency. The &VIDIOC-G-TUNER; or
+&VIDIOC-G-MODULATOR; ioctl
 reports the supported frequency range.</para>
   </section>