Hi Ramesh,
On Tuesday 11 Apr 2017 09:57:45 Ramesh Shanmugasundaram wrote:
> > On Tuesday 07 Feb 2017 15:02:32 Ramesh Shanmugasundaram wrote:
> >> Add device tree binding documentation for MAX2175 Rf to bits tuner
> >> device.
> >>
> >> Signed-off-by: Ramesh Shanmugasundaram
> >> <ramesh.shanmugasunda...@bp.renesas.com> ---
> >>
> >> .../devicetree/bindings/media/i2c/max2175.txt | 61 +++++++++++++++
> >> .../devicetree/bindings/property-units.txt | 1 +
> >> 2 files changed, 62 insertions(+)
> >> create mode 100644
> >>
> >> Documentation/devicetree/bindings/media/i2c/max2175.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/media/i2c/max2175.txt
> >> b/Documentation/devicetree/bindings/media/i2c/max2175.txt new file
> >> mode 100644
> >> index 0000000..f591ab4
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/media/i2c/max2175.txt
[snip]
> >> +- maxim,am-hiz : empty property indicates AM Hi-Z filter path
> >> is
> >> + selected for AM antenna input. By default this
> >> + filter path is not used.
> >
> > Isn't this something that should be selected at runtime through a control
> > ? Or does the hardware design dictate whether the filter has to be used or
> > must not be used ?
>
> This is dictated by the h/w design and not selectable at run-time.
> I will update these changes in the next patchset.
In that case I'm fine with a property, but could we name it in such a way that
it describes the hardware instead of instructing the software on how to
configure the device ? For instance (and this is a made-up example as I don't
know exactly how this works), if the AM Hi-Z filter is required when dealing
with AM frequencies and forbidden when dealing with other frequency bands, and
*if* boards have to be designed specifically for one frequency band (AM, FM,
VHF, L, ...) without any way to accept different bands, then you could instead
use
maxim,frequency-band = "AM";
and enable the filter accordingly in the driver. This would be in my opinion a
better system hardware description.
--
Regards,
Laurent Pinchart
