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authorMauro Carvalho Chehab <mchehab@redhat.com>2011-06-07 20:43:25 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-07-27 17:52:45 -0300
commitdf2692a6dd89fc00929a18735b83204b352ebb52 (patch)
tree61895d345c72e08e7ac879eaf05c904864b5aa23 /Documentation/DocBook
parent17d8bb061fcf8ba6a56adcf193d7d255966cff79 (diff)
downloadop-kernel-dev-df2692a6dd89fc00929a18735b83204b352ebb52.zip
op-kernel-dev-df2692a6dd89fc00929a18735b83204b352ebb52.tar.gz
[media] DocBook/frontend.xml: Recomend the usage of the new API
The old way of setting delivery system parameters were to use an union with specific per-system parameters. However, as newer delivery systems required more data, the structure size weren't enough to fit. So, recomend using the DVBS2API instead. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r--Documentation/DocBook/media/dvb/frontend.xml16
1 files changed, 14 insertions, 2 deletions
diff --git a/Documentation/DocBook/media/dvb/frontend.xml b/Documentation/DocBook/media/dvb/frontend.xml
index b1f0123..086e62b 100644
--- a/Documentation/DocBook/media/dvb/frontend.xml
+++ b/Documentation/DocBook/media/dvb/frontend.xml
@@ -221,8 +221,20 @@ by</para>
<section id="dvb-frontend-parameters">
<title>frontend parameters</title>
<para>The kind of parameters passed to the frontend device for tuning depend on
-the kind of hardware you are using. All kinds of parameters are combined as an
-union in the FrontendParameters structure:</para>
+the kind of hardware you are using.</para>
+<para>The struct <constant>dvb_frontend_parameters</constant> uses an
+union with specific per-system parameters. However, as newer delivery systems
+required more data, the structure size weren't enough to fit, and just
+extending its size would break the existing applications. So, those parameters
+were replaced by the usage of <link linkend="FE_GET_SET_PROPERTY">
+<constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant></link> ioctl's. The
+new API is flexible enough to add new parameters to existing delivery systems,
+and to add newer delivery systems.</para>
+<para>So, newer applications should use <link linkend="FE_GET_SET_PROPERTY">
+<constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant></link> instead, in
+order to be able to support the newer System Delivery like DVB-S2, DVB-T2,
+DVB-C2, ISDB, etc.</para>
+<para>All kinds of parameters are combined as an union in the FrontendParameters structure:</para>
<programlisting>
struct dvb_frontend_parameters {
uint32_t frequency; /&#x22C6; (absolute) frequency in Hz for QAM/OFDM &#x22C6;/
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