V4L/DVB: IR: extend interfaces to support more device settings

LIRC: add new IOCTL that enables learning mode (wide band receiver)
Still missing features: carrier report & timeout reports.
Will need to pack these into ir_raw_event

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/DocBook/v4l/lirc_device_interface.xml

@@ -229,6 +229,22 @@ on working with the default settings initially.</para>
       and LIRC_SETUP_END. Drivers can also choose to ignore these ioctls.</para>
     </listitem>
   </varlistentry>
+  <varlistentry>
+    <term>LIRC_SET_WIDEBAND_RECEIVER</term>
+    <listitem>
+      <para>Some receivers are equipped with special wide band receiver which is intended
+      to be used to learn output of existing remote.
+      Calling that ioctl with (1) will enable it, and with (0) disable it.
+      This might be useful of receivers that have otherwise narrow band receiver
+      that prevents them to be used with some remotes.
+      Wide band receiver might also be more precise
+      On the other hand its disadvantage it usually reduced range of reception.
+      Note: wide band receiver might be implictly enabled if you enable
+      carrier reports. In that case it will be disabled as soon as you disable
+      carrier reports. Trying to disable wide band receiver while carrier
+      reports are active will do nothing.</para>
+    </listitem>
+  </varlistentry>
 </variablelist>
 
 </section>