Re: [PATCH 1/2] arm64: dts: qcom: Enable lvds panel-DV215FHM-R01 for rb3gen2 industrial mezzanine

[Bjorn Andersson]

On Wed, Nov 12, 2025 at 10:16:27PM +0200, Dmitry Baryshkov wrote:
> On Wed, Nov 12, 2025 at 10:53:36AM -0600, Bjorn Andersson wrote:
> > On Wed, Nov 12, 2025 at 05:02:20PM +0200, Dmitry Baryshkov wrote:
> > > On Wed, Nov 12, 2025 at 08:18:11PM +0530, Gopi Botlagunta wrote:
> > > > Below is the routing diagram of dsi lanes from qcs6490 soc to
> > > > mezzanine.
> > > > 
> > > > DSI0 --> SW1403.4 --> LT9611uxc --> hdmi port
> > > >                  |
> > > >                   --> SW2700.1 --> dsi connector
> > > >                               |
> > > >                                --> LT9211c --> LVDS connector
> > > > 
> > > > Disable hdmi connector for industrial mezzanine and enable
> > > > LT9211c bridge and lvds panel node.
> > > > LT9211c is powered by default with reset gpio connected to 117.
> > > > 
> > > > Signed-off-by: Yi Zhang <zhanyi@xxxxxxxxxxxxxxxx>
> > > > Signed-off-by: Gopi Botlagunta <venkata.botlagunta@xxxxxxxxxxxxxxxx>
> > > > ---
> > > >  .../qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso | 106 +++++++++++++++++++++
> > > >  1 file changed, 106 insertions(+)
> > > > 
> > > > diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> > > > index 619a42b5ef48..cc8ee1643167 100644
> > > > --- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> > > > +++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2-industrial-mezzanine.dtso
> > > > @@ -8,6 +8,112 @@
> > > >  #include <dt-bindings/clock/qcom,gcc-sc7280.h>
> > > >  #include <dt-bindings/pinctrl/qcom,pmic-gpio.h>
> > > >  
> > > > +/ {
> > > > +
> > > > +	hdmi-connector {
> > > > +		status = "disabled";
> > > > +	};
> > > > +
> > > > +	panel_lvds: panel-lvds@0 {
> > > > +		compatible = "panel-lvds";
> > > 
> > > Please describe the actual panel using compatible, etc. It's not that
> > > this is some generic uknown LVDS panel.
> > > 
> > 
> > I presume the mezzanine doesn't have a panel, so how do we provide the
> > description of the mezzanine such that a developer can quickly get up to
> > speed with their specific panel connected to it?
> > 
> > Do we leave this node disabled, just for reference, or do we specify a
> > specific panel and then have the developer copy and adopt this to their
> > panel?
> > 
> > The benefit of doing it like that is that we provide a complete example
> > and something we can test. But at the same time, If I presume we might
> > have users of the mezzanine without an attached LVDS panel?
> > 
> > > > +		data-mapping = "vesa-24";
> > > > +		width-mm = <476>;
> > > > +		height-mm = <268>;
> > 
> > The way this patch is written we certainly have some specific panel in
> > mind...
> 
> It's even mentioned in the subject: BOE DV215FHM-R01. Having a proper
> panel compatible is demanded by the panel-lvds bindings.
> 

I missed that mention. But that implies then that this isn't "the
industrial mezzanine", but "the industrial mezznine with a boe
DV215FHM-R01 connected".

Are you saying that this is the way you'd prefer that we handle the
mezzanines with capabilities for extension?

Regards,
Bjorn

> 
> -- 
> With best wishes
> Dmitry