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| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-11-11 18:46:23 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-11-11 18:46:23 +0400 |
| commit | 39ce61a846c8e1fa00cb57ad5af021542e6e8403 (patch) | |
| tree | fc2ece73b3c54a805f9ac85d390f2388f741b46c | |
| parent | e9eb0dadba932940f721f9d27544a7818b2fa1c5 (diff) | |
| download | linux-39ce61a846c8e1fa00cb57ad5af021542e6e8403.tar.xz | |
[media] dvb: Allow select between DVB-C Annex A and Annex C
DVB-C, as defined by ITU-T J.83 has 3 annexes. The differences between
Annex A and Annex C is that Annex C uses a subset of the modulation
types, and uses a different rolloff factor. A different rolloff means
that the bandwidth required is slicely different, and may affect the
saw filter configuration at the tuners. Also, some demods have different
configurations, depending on using Annex A or Annex C.
So, allow userspace to specify it, by changing the rolloff factor.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | Documentation/DocBook/media/dvb/dvbproperty.xml | 4 | ||||
| -rw-r--r-- | drivers/media/dvb/dvb-core/dvb_frontend.c | 2 | ||||
| -rw-r--r-- | include/linux/dvb/frontend.h | 2 |
3 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml index 3bc8a61efe30..6ac803959a47 100644 --- a/Documentation/DocBook/media/dvb/dvbproperty.xml +++ b/Documentation/DocBook/media/dvb/dvbproperty.xml @@ -311,6 +311,8 @@ typedef enum fe_rolloff { ROLLOFF_20, ROLLOFF_25, ROLLOFF_AUTO, + ROLLOFF_15, /* DVB-C Annex A */ + ROLLOFF_13, /* DVB-C Annex C */ } fe_rolloff_t; </programlisting> </section> @@ -778,8 +780,10 @@ typedef enum fe_hierarchy { <listitem><para><link linkend="DTV-MODULATION"><constant>DTV_MODULATION</constant></link></para></listitem> <listitem><para><link linkend="DTV-INVERSION"><constant>DTV_INVERSION</constant></link></para></listitem> <listitem><para><link linkend="DTV-SYMBOL-RATE"><constant>DTV_SYMBOL_RATE</constant></link></para></listitem> + <listitem><para><link linkend="DTV-ROLLOFF"><constant>DTV_ROLLOFF</constant></link></para></listitem> <listitem><para><link linkend="DTV-INNER-FEC"><constant>DTV_INNER_FEC</constant></link></para></listitem> </itemizedlist> + <para>The Rolloff of 0.15 (ROLLOFF_15) is assumed, as ITU-T J.83 Annex A is more common. For Annex C, rolloff should be 0.13 (ROLLOFF_13). All other values are invalid.</para> </section> <section id="dvbc-annex-b-params"> <title>DVB-C Annex B delivery system</title> diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c index 2c0acdb4d811..c849455458ea 100644 --- a/drivers/media/dvb/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb/dvb-core/dvb_frontend.c @@ -876,6 +876,7 @@ static int dvb_frontend_clear_cache(struct dvb_frontend *fe) c->symbol_rate = QAM_AUTO; c->code_rate_HP = FEC_AUTO; c->code_rate_LP = FEC_AUTO; + c->rolloff = ROLLOFF_AUTO; c->isdbt_partial_reception = -1; c->isdbt_sb_mode = -1; @@ -1030,6 +1031,7 @@ static void dtv_property_cache_init(struct dvb_frontend *fe, break; case FE_QAM: c->delivery_system = SYS_DVBC_ANNEX_AC; + c->rolloff = ROLLOFF_15; /* implied for Annex A */ break; case FE_OFDM: c->delivery_system = SYS_DVBT; diff --git a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h index 1b1094c35e4f..d9251df867b5 100644 --- a/include/linux/dvb/frontend.h +++ b/include/linux/dvb/frontend.h @@ -329,6 +329,8 @@ typedef enum fe_rolloff { ROLLOFF_20, ROLLOFF_25, ROLLOFF_AUTO, + ROLLOFF_15, /* DVB-C Annex A */ + ROLLOFF_13, /* DVB-C Annex C */ } fe_rolloff_t; typedef enum fe_delivery_system { |