On Wed, Jul 11, 2012 at 1:01 PM, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > Hi Hans, > > Thanks for the patch. > > I've CC-ed Halli as well. > > On Wed July 11 2012 17:47:34 Hans de Goede wrote: >> To allow apps to limit a hw-freq-seek to a specific band, for further >> info see the documentation this patch adds for these new fields. >> >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> --- >> .../DocBook/media/v4l/vidioc-s-hw-freq-seek.xml | 44 ++++++++++++++++---- >> include/linux/videodev2.h | 5 ++- >> 2 files changed, 40 insertions(+), 9 deletions(-) >> >> diff --git a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml >> index f4db44d..50dc9f8 100644 >> --- a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml >> +++ b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml >> @@ -52,11 +52,21 @@ >> <para>Start a hardware frequency seek from the current frequency. >> To do this applications initialize the <structfield>tuner</structfield>, >> <structfield>type</structfield>, <structfield>seek_upward</structfield>, >> -<structfield>spacing</structfield> and >> -<structfield>wrap_around</structfield> fields, and zero out the >> -<structfield>reserved</structfield> array of a &v4l2-hw-freq-seek; and >> -call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> ioctl with a pointer >> -to this structure.</para> >> +<structfield>wrap_around</structfield>, <structfield>spacing</structfield>, >> +<structfield>rangelow</structfield> and <structfield>rangehigh</structfield> >> +fields, and zero out the <structfield>reserved</structfield> array of a >> +&v4l2-hw-freq-seek; and call the <constant>VIDIOC_S_HW_FREQ_SEEK</constant> >> +ioctl with a pointer to this structure.</para> >> + >> + <para>The <structfield>rangelow</structfield> and >> +<structfield>rangehigh</structfield> fields can be set to a non-zero value to >> +tell the driver to search a specific band. If the &v4l2-tuner; >> +<structfield>capability</structfield> field has the >> +<constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag set, these values >> +must fall within one of the bands returned by &VIDIOC-ENUM-FREQ-BANDS;. If >> +the <constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant> flag is not set, >> +then these values must exactly match those of one of the bands returned by >> +&VIDIOC-ENUM-FREQ-BANDS;.</para> > > OK, I have some questions here: > > 1) If you have a multiband tuner, what should happen if both low and high are > zero? Currently it is undefined, other than that the seek should start from > the current frequency until it reaches some limit. > > Halli, what does your hardware do? In particular, is the hwseek limited by the > US/Europe or Japan band range or can it do the full range? If I'm not mistaken > it is the former, right? You are right... my hardware seek is limited by the japan/US band range.... > If it is the former, then you need to explicitly set low + high to ensure that > the hwseek uses the correct range because the driver can't guess which of the > overlapping bands to use. Yes in my driver I will take care of this :).... > > 2) What happens if the current frequency is outside the low/high range? The > hwseek spec says that the seek starts from the current frequency, so that might > mean that hwseek returns -ERANGE in this case. > > Regards, > > Hans -- Regards Halli -- 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
