On Sat May 5 2012 00:41:34 Hans Verkuil wrote: > > + <table pgwide="1" frame="none" id="Radio band Types"> > > + <title>Radio Band Types</title> > > + <tgroup cols="2"> > > + &cs-str; > > + <tbody valign="top"> > > + <row> > > + <entry><constant>FM_BAND_TYPE_ALL</constant> </entry> > > + <entry>All Bands from 65.8 MHz till 108 Mhz or 162.55 MHz if weather band.</entry> > > + </row> > > Hmm, I have to thing about that name. And about other related issues as well: > what to do if a band isn't supported? How does an application know which bands are > in fact supported? > > It's too late and I'll have to think about this tomorrow. OK, I've thought about this a bit more. First of all we need a way to detect which bands are supported. I propose to add capability flags to struct v4l2_tuner, one for each band. There are more than enough capability flags available, so we can start from bit 16 and add 4 capability flags for the four bands. Since applications can now detect which bands are available, it is OK for the SEEK ioctl to return -EINVAL if the band isn't present. Please update the SEEK ioctl documentation accordingly. With respect to the name FM_BAND_TYPE_ALL: I propose to rename that to _TYPE_DEFAULT. The description should be something like: "This is the default band, which should be the widest frequency range supported by the hardware." I think that is a better name since that is what drivers to at the moment. I don't think you can guarantee an 'All bands' setting as that is often limited by the hardware. What do you think? Regards, Hans > > Regards, > > Hans > > > + <row> > > + <entry><constant>FM_BAND_TYPE_EUROPE_US</constant> </entry> > > + <entry>Europe or US band(87.5 Mhz - 108 MHz).</entry> > > + </row> > > + <row> > > + <entry><constant>FM_BAND_TYPE_JAPAN</constant> </entry> > > + <entry>Japan band(76 MHz - 90 MHz).</entry> > > + </row> > > + <row> > > + <entry><constant>FM_BAND_TYPE_RUSSIAN</constant> </entry> > > + <entry>OIRT or Russian band(65.8 MHz - 74 MHz).</entry> > > + </row> > > + <row> > > + <entry><constant>FM_BAND_TYPE_WEATHER</constant> </entry> > > + <entry>Weather band(162.4 MHz - 162.55 MHz).</entry> > > + </row> > > + </tbody> > > + </tgroup> > > + </table> > > > > <refsect1> > > &return-value; > > > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
