Re: [PATCH v2 3/7] drm/panel: simple: Add waiken WKS101WX001-WCT support

[Liu Ying <victor.liu@nxp.com>]

On Thu, Jul 23, 2026 at 10:16:18PM -0500, Frank Li wrote:
> On Fri, Jul 24, 2026 at 10:27:13AM +0800, Liu Ying wrote:
> > On Thu, Jul 23, 2026 at 04:36:39PM -0500, Frank Li wrote:
> > > On Thu, Jul 23, 2026 at 10:22:10AM +0800, Liu Ying wrote:
> > > > On Wed, Jul 22, 2026 at 05:12:47PM -0500, Frank Li wrote:
> > > > > On Wed, Jul 22, 2026 at 11:57:09AM +0800, Liu Ying wrote:
> > > > > > On Wed, Jul 22, 2026 at 11:44:09AM +0800, Liu Ying wrote:
> > > > > > > On Tue, Jul 21, 2026 at 07:05:03PM -0500, Frank Li wrote:
> > > > > > > > On Fri, Jul 17, 2026 at 01:48:31PM +0800, Liu Ying wrote:
> > > > > > > > > On Wed, Jul 15, 2026 at 02:34:48PM -0400, Frank.Li@oss.nxp.com wrote:
> > > > > > > > > > From: Frank Li <Frank.Li@nxp.com>
> > > > > > > > > >
> > > > > > > > > > Add support for WKS101WX001-WCT panel, which is an industrial-grade
> > > > > > > > > > 10.1-inch IPS TFT LCD capacitive touch screen display module.
> > > > > > > > > >
> > > > > > > > > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > > > > > > > > ---
> > > > > > > > > > change in v2
> > > > > > > > > > - update height to 135 from 136 (sashiko)
> > > > > > > > > > ---
> > > > > > > > > >  drivers/gpu/drm/panel/panel-simple.c | 31 +++++++++++++++++++++++++++++++
> > > > > > > > > >  1 file changed, 31 insertions(+)
> > > > > > >
> > > > > > > [...]
> > > > > > >
> > > > > > > > > > +	.connector_type = DRM_MODE_CONNECTOR_DPI,
> > > > > > > > >
> > > > > > > > > Seems that the panel also supports LVDS input according to the specification,
> > > > > > > > > since it mentions 'RGB or LVDS Interface'?
> > > > > > > >
> > > > > > > > Need hardware rework to use LVDS. Need remove banch of resistors. Should it
> > > > > > > > be treat as difference panel by different compatible string? hardware
> > > > > > > > actually changed.
> > > > > > >
> > > > > > > Not sure how to handle that.
> > > > > >
> > > > > > Wait, you probably may drop this patch, just document the compatible
> > > > > > string in panel-simple.yaml and panel-lvds.yaml and use add a fallback
> > >
> > > panel-simple.yaml don't allow fallback to panel-dpi. Need seperated yaml
> > > for it.
> >
> > Really?  How does it disallow that?
> >
> > I can see newhaven,nhd-4.3-480272ef-atxl and osddisplays,osd070t1718-19ts
> > are documented in panel-simple.yaml and used with the "panel-dpi" fallback
> > compatible string.
> >
> > Documentation/devicetree/bindings/display/panel/panel-simple.yaml:244:      - newhaven,nhd-4.3-480272ef-atxl
> > arch/arm/boot/dts/ti/omap/am437x-sk-evm.dts:127:                compatible = "newhaven,nhd-4.3-480272ef-atxl", "panel-dpi";
> >
> > Documentation/devicetree/bindings/display/panel/panel-simple.yaml:268:      - osddisplays,osd070t1718-19ts
> > arch/arm/boot/dts/ti/omap/am437x-gp-evm.dts:89:         compatible = "osddisplays,osd070t1718-19ts", "panel-dpi";
> > arch/arm/boot/dts/ti/omap/am43x-epos-evm.dts:45:                compatible = "osddisplays,osd070t1718-19ts", "panel-dpi";
> > arch/arm/boot/dts/ti/omap/am57xx-evm.dtso:62:           compatible = "osddisplays,osd070t1718-19ts", "panel-dpi";
> 
> It can't pass DTB_CHECK. it may add at earily time. panel-simple.yaml
> have not fallback compatible string. I tried it. DTB_CHECK will complain
> too long compatible string if add "panel-dpi".

Yeah, I missed testing panel-simple.yaml with DTB_CHECK.

So, just don't document the panel compatible string in panel-simple.yaml
and only document it in panel-lvds.yaml(not today, but until someone really
uses it).  Then, I'd assume that the "fallback compatible" solution still
works.

> 
> >
> > >
> > > > > > compatible string "panel-dpi" or "panel-lvds" in device tree plus a
> > > > > > panel-timing node.
> > >
> > > previous dt-binding discuss, don't allow failback to two compatible string
> > > sorry, I can't remember exactly thread.
> > >
> > > like
> > > items:
> > >   - const: ws101w001-wct
> > >   - enum:
> > >        - panel-dpi
> > >        - panel-lvds
> >
> > I meant just to document the panel in panel-simple.yaml and panel-lvds.yaml.
> > No need to add a dedicated DT binding file with such a compatible property
> > for this panel.
> 
> panel-lvds.yaml allow fallback to panel-lvds, but panel-simple.yaml not.
> all binding which allow fallback to panel-dpi, there are seperate yaml file
> for it.
> 
> of course TI or old platform, especially arm32 platform wrongly use it
> regardless DTB check warning. But for new platform, we can't do that as it.
> 
> Frank
> >
> > >
> > > > >
> > > > > Look like recently prefer add panel-timing informaiton into c code instead
> > > > > of put it into dts file. But I am not sure about it. Just check recent's
> > > > > log history.
> > > >
> > > > If display timing is specified in panel-simple.c, then you have to specify
> > > > the connector_type there too, right?  The problem here is that you don't
> > > > know the connector_type, as it could be either LVDS or DPI, and I'd assume
> > > > that we don't want two compatible strings - one for LVDS and the other for
> > > > DPI.
> > >
> > > If supported both type, generally need customer property and new panel
> > > driver to switch between dpi / lvds
> > >
> > > or use
> > > 	ports {
> > >
> > > 		port@0: //connect dpi
> > > 		port@1: //connect lvds
> > > 	};
> >
> > I'd say a new panel driver for this panel is a bit overkill.
> >
> > >
> > >
> > > I think we can defer this lvds work until it is actually used because
> > > - need a big hardware rework to support lvds, most likely it will not be
> >
> > Per panel spec, just remove a few resistors, which doesn't sound like a
> > big rework to me.  But, perhaps, this doesn't impact SW solution a lot though.
> >
> > > appeared at real productions. If it mass production, vendor most likely use
> > > difference module number for it.
> > > - it may be end of life if there are not much users.
> >
> > I'd prefer a mature solution which handles both DPI and LVDS interfaces
> > correctly in the first place.
> >
> > Anyway, just my two cents here.  "DRM PANEL DRIVERS" maintainers or DRM
> > subsystem maintainers may override me.
> >
> > >
> > > Frank
> > >
> > > > Although display timing in panel-simple.c avoids duplicated panel-timing
> > > > nodes across various potential DT files, I think you have the "good" reason
> > > > here to use the panel-timing node + fallback compatible string with one single
> > > > panel specific compatible string.
> > > >
> > > > >
> > > > > Add Neil Armstrong for comments.
> > > > >
> > > > > Frank
> > > > >
> > > > > >
> > > > > > --
> > > > > > Regards,
> > > > > > Liu Ying
> > > >
> > > > --
> > > > Regards,
> > > > Liu Ying
> >
> > --
> > Regards,
> > Liu Ying

-- 
Regards,
Liu Ying