FM Receiver Control Reference

document, from CENELEC. >> >> >> +

>> + FM Receiver Control Reference >> + >> + The FM Receiver (FM_RX) class includes controls for common features of >> +FM Reception capable devices. Currently this class includes parameter for Alternate >> +frequency. >> + >> + >> + FM_RX Control IDs >> + >> + >> + >> + >> + >> + >> + >> + >> + >> + >> + ID >> + Type >> + Description >> + >> + >> + >> + >> + >> + V4L2_CID_FM_RX_CLASS >> + class >> + The FM_RX class >> +descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a >> +description of this control class. >> + >> + >> + V4L2_CID_RDS_AF_SWITCH >> + boolean >> + >> + Enable or Disable's FM RX RDS Alternate frequency feature. > > How does this work? If this is enabled, will the receiver automagically switch to > the alternate frequency if the signal becomes too weak? And how does that affect > VIDIOC_G_FREQUENCY? Yes, when signal strength of current channel goes below the threshold then driver will switch to the AF frequency and updates the VIDIOC_G_FREQUENCY accordingly. > >> + >> + >> + V4L2_CID_TUNE_DEEMPHASIS >> + integer >> + >> + Configures the de-emphasis value for reception. >> +A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies. >> +Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_deemphasis >> +defines possible values for pre-emphasis. Here they are: > > Should enum v4l2_preemphasis be reused here? I'm not certain what's best myself. Sure we can use the same enum for both FM RX and TX, but shall I name it as "enum v4l2_emphasis_filter" (as in case of RX its de-emphasis and in TX its Pre-Emphasis) > >> + >> + >> + >> + >> + V4L2_DEEMPHASIS_DISABLED >> + No de-emphasis is applied. >> + >> + >> + V4L2_DEEMPHASIS_50_uS >> + A de-emphasis of 50 uS is used. >> + >> + >> + V4L2_DEEMPHASIS_75_uS >> + A de-emphasis of 75 uS is used. >> + >> + >> + >> + >> + >> + >> + >> + >> +

>> + >> +

>> Flash Control Reference >> >> diff --git a/Documentation/DocBook/media/v4l/dev-rds.xml b/Documentation/DocBook/media/v4l/dev-rds.xml >> index 38883a4..8188161 100644 >> --- a/Documentation/DocBook/media/v4l/dev-rds.xml >> +++ b/Documentation/DocBook/media/v4l/dev-rds.xml >> @@ -55,8 +55,9 @@ If the driver only passes RDS blocks without interpreting the data >> the V4L2_TUNER_CAP_RDS_BLOCK_IO flag has to be set. If the >> tuner is capable of handling RDS entities like program identification codes and radio >> text, the flag V4L2_TUNER_CAP_RDS_CONTROLS should be set, >> -see Writing RDS data and >> -FM Transmitter Control Reference. >> +see Writing RDS data, >> +FM Transmitter Control Reference >> +FM Receiver Control Reference. >>

>> >>

>> diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml >> index b17a7aa..2a8b44e 100644 >> --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml >> +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml >> @@ -258,6 +258,13 @@ These controls are described in > These controls are described in > linkend="fm-tx-controls" />. >> >> + >> + V4L2_CTRL_CLASS_FM_RX >> + 0x9c0000 >> + The class containing FM Receiver (FM RX) controls. >> +These controls are described in > + linkend="fm-rx-controls" />. >> + >> >> V4L2_CTRL_CLASS_FLASH >> 0x9c0000 >> > > I'm missing the documentation for the new fm_band field! I missed it :(. will add this in next patch set > > Regards, > > Hans > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Regards Halli