diff mbox

[1/2] dvb: frontend API: Add a flag to indicate that get_frontend() can be called

Message ID 1326909085-14256-1-git-send-email-mchehab@redhat.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

Mauro Carvalho Chehab Jan. 18, 2012, 5:51 p.m. UTC 
get_frontend() can't be called too early, as the device may not have it
yet. Yet, get_frontend() on OFDM standards can happen before FE_HAS_LOCK,
as the TMCC carriers (ISDB-T) or the TPS carriers (DVB-T) require a very
low signal to noise relation to be detected. The other carriers use
diff mbox

Patch

different modulations, so they require a higher SNR.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 Documentation/DocBook/media/dvb/frontend.xml |   59 +++++++++++++++++++++-----
 include/linux/dvb/frontend.h                 |   33 ++++++++++----
 2 files changed, 72 insertions(+), 20 deletions(-)

diff --git a/Documentation/DocBook/media/dvb/frontend.xml b/Documentation/DocBook/media/dvb/frontend.xml
index aeaed59..5426bdc 100644
--- a/Documentation/DocBook/media/dvb/frontend.xml
+++ b/Documentation/DocBook/media/dvb/frontend.xml
@@ -207,18 +207,55 @@  spec.</para>
 <para>Several functions of the frontend device use the fe_status data type defined
 by</para>
 <programlisting>
- typedef enum fe_status {
-	 FE_HAS_SIGNAL     = 0x01,   /&#x22C6;  found something above the noise level &#x22C6;/
-	 FE_HAS_CARRIER    = 0x02,   /&#x22C6;  found a DVB signal  &#x22C6;/
-	 FE_HAS_VITERBI    = 0x04,   /&#x22C6;  FEC is stable  &#x22C6;/
-	 FE_HAS_SYNC       = 0x08,   /&#x22C6;  found sync bytes  &#x22C6;/
-	 FE_HAS_LOCK       = 0x10,   /&#x22C6;  everything's working... &#x22C6;/
-	 FE_TIMEDOUT       = 0x20,   /&#x22C6;  no lock within the last ~2 seconds &#x22C6;/
-	 FE_REINIT         = 0x40    /&#x22C6;  frontend was reinitialized,  &#x22C6;/
- } fe_status_t;                      /&#x22C6;  application is recommned to reset &#x22C6;/
+typedef enum fe_status {
+	FE_HAS_SIGNAL		= 0x01,
+	FE_HAS_CARRIER		= 0x02,
+	FE_HAS_VITERBI		= 0x04,
+	FE_HAS_SYNC		= 0x08,
+	FE_HAS_LOCK		= 0x10,
+	FE_TIMEDOUT		= 0x20,
+	FE_REINIT		= 0x40,
+	FE_HAS_PARAMETERS	= 0x80,
+} fe_status_t;
 </programlisting>
-<para>to indicate the current state and/or state changes of the frontend hardware.
-</para>
+<para>to indicate the current state and/or state changes of the frontend hardware:
+</para>
+
+<informaltable><tgroup cols="2"><tbody>
+<row>
+<entry align="char">FE_HAS_SIGNAL</entry>
+<entry align="char">The frontend has found something above the noise level</entry>
+</row><row>
+<entry align="char">FE_HAS_CARRIER</entry>
+<entry align="char">The frontend has found a DVB signal</entry>
+</row><row>
+<entry align="char">FE_HAS_VITERBI</entry>
+<entry align="char">The frontend FEC code is stable</entry>
+</row><row>
+<entry align="char">FE_HAS_SYNC</entry>
+<entry align="char">Syncronization bytes was found</entry>
+</row><row>
+<entry align="char">FE_HAS_LOCK</entry>
+<entry align="char">The DVB were locked and everything is working</entry>
+</row><row>
+<entry align="char">FE_TIMEDOUT</entry>
+<entry align="char">no lock within the last about 2 seconds</entry>
+</row><row>
+<entry align="char">FE_REINIT</entry>
+<entry align="char">The frontend was reinitialized, application is
+recommended to reset DiSEqC, tone and parameters</entry>
+</row><row>
+<entry align="char">FE_HAS_PARAMETERS</entry>
+<entry align="char"><link linkend="FE_GET_SET_PROPERTY">
+<constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant></link> or
+<link linkend="FE_GET_FRONTEND"><constant>FE_GET_FRONTEND</constant></link> can now be
+called to provide the detected network parameters.
+This should be risen for example when the DVB-T TPS/ISDB-T TMCC is locked.
+This status can be risen before FE_HAS_SYNC, as the SNR required for
+parameters detection is lower than the requirement for the other
+carriers on the OFDM delivery systems.
+</entry>
+</row></tbody></tgroup></informaltable>
 
 </section>
 
diff --git a/include/linux/dvb/frontend.h b/include/linux/dvb/frontend.h
index cb4428a..38fa9ef 100644
--- a/include/linux/dvb/frontend.h
+++ b/include/linux/dvb/frontend.h
@@ -121,16 +121,31 @@  typedef enum fe_sec_mini_cmd {
 } fe_sec_mini_cmd_t;
 
 
+/**
+ * enum fe_status - enumerates the possible frontend status
+ * @FE_HAS_SIGNAL:	found something above the noise level
+ * @FE_HAS_CARRIER:	found a DVB signal
+ * @FE_HAS_VITERBI:	FEC is stable
+ * @FE_HAS_SYNC:	found sync bytes
+ * @FE_HAS_LOCK:	everything's working
+ * @FE_TIMEDOUT:	no lock within the last ~2 seconds
+ * @FE_REINIT:		frontend was reinitialized, application is recommended
+ *			to reset DiSEqC, tone and parameters
+ * @FE_HAS_PARAMETERS:	get_frontend() can now be called to provide the
+ *			detected network parameters. This should be risen
+ *			for example when the DVB-T TPS/ISDB-T TMCC is locked.
+ */
+
 typedef enum fe_status {
-	FE_HAS_SIGNAL	= 0x01,   /* found something above the noise level */
-	FE_HAS_CARRIER	= 0x02,   /* found a DVB signal  */
-	FE_HAS_VITERBI	= 0x04,   /* FEC is stable  */
-	FE_HAS_SYNC	= 0x08,   /* found sync bytes  */
-	FE_HAS_LOCK	= 0x10,   /* everything's working... */
-	FE_TIMEDOUT	= 0x20,   /* no lock within the last ~2 seconds */
-	FE_REINIT	= 0x40    /* frontend was reinitialized,  */
-} fe_status_t;			  /* application is recommended to reset */
-				  /* DiSEqC, tone and parameters */
+	FE_HAS_SIGNAL		= 0x01,
+	FE_HAS_CARRIER		= 0x02,
+	FE_HAS_VITERBI		= 0x04,
+	FE_HAS_SYNC		= 0x08,
+	FE_HAS_LOCK		= 0x10,
+	FE_TIMEDOUT		= 0x20,
+	FE_REINIT		= 0x40,
+	FE_HAS_PARAMETERS	= 0x80,
+} fe_status_t;
 
 typedef enum fe_spectral_inversion {
 	INVERSION_OFF,