[media] DocBook: Add an example for using FE_SET_PROPERTY

[cascardo/linux.git] / Documentation / DocBook / media / dvb / dvbproperty.xml

diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml
index b91210d..00ba1a9 100644 (file)
--- a/Documentation/DocBook/media/dvb/dvbproperty.xml
+++ b/Documentation/DocBook/media/dvb/dvbproperty.xml
@@ -15,11 +15,13 @@
     approach, in favor of a properties set approach.</para>
 <para>By using a properties set, it is now possible to extend and support any
     digital TV without needing to redesign the API</para>
+
 <para>Example: with the properties based approach, in order to set the tuner
     to a DVB-C channel at 651 kHz, modulated with 256-QAM, FEC 3/4 and symbol
     rate of 5.217 Mbauds, those properties should be sent to
     <link linkend="FE_GET_PROPERTY"><constant>FE_SET_PROPERTY</constant></link> ioctl:</para>
     <itemizedlist>
+       <listitem>&DTV-DELIVERY-SYSTEM; = SYS_DVBC_ANNEX_A</listitem>
        <listitem>&DTV-FREQUENCY; = 651000000</listitem>
        <listitem>&DTV-MODULATION; = QAM_256</listitem>
        <listitem>&DTV-INVERSION; = INVERSION_AUTO</listitem>
@@ -27,6 +29,44 @@
        <listitem>&DTV-INNER-FEC; = FEC_3_4</listitem>
        <listitem>&DTV-TUNE;</listitem>
     </itemizedlist>
+
+<para>The code that would do the above is:</para>
+<programlisting>
+#include &lt;stdio.h&gt;
+#include &lt;fcntl.h&gt;
+#include &lt;sys/ioctl.h&gt;
+#include &lt;linux/dvb/frontend.h&gt;
+
+static struct dtv_property props[] = {
+       { .cmd = DTV_DELIVERY_SYSTEM, .u.data = SYS_DVBC_ANNEX_A },
+       { .cmd = DTV_FREQUENCY,       .u.data = 651000000 },
+       { .cmd = DTV_MODULATION,      .u.data = QAM_256 },
+       { .cmd = DTV_INVERSION,       .u.data = INVERSION_AUTO },
+       { .cmd = DTV_SYMBOL_RATE,     .u.data = 5217000 },
+       { .cmd = DTV_INNER_FEC,       .u.data = FEC_3_4 },
+       { .cmd = DTV_TUNE }
+};
+
+static struct dtv_properties dtv_prop = {
+       .num = 6, .props = props
+};
+
+int main(void)
+{
+       int fd = open("/dev/dvb/adapter0/frontend0", O_RDWR);
+
+       if (!fd) {
+           perror ("open");
+           return -1;
+       }
+       if (ioctl(fd, FE_SET_PROPERTY, &amp;dtv_prop) == -1) {
+               perror("ioctl");
+               return -1;
+       }
+       printf("Frontend set\n");
+       return 0;
+}
+</programlisting>
 <para>NOTE: This section describes the DVB version 5 extension of the DVB-API,
 also called "S2API", as this API were added to provide support for DVB-S2. It
 was designed to be able to replace the old frontend API. Yet, the DISEQC and