Re: [PATCH 0/4] drm/panel: simple: add Waveshare LCD panels

[Marek Vasut]

On 3/31/26 5:36 PM, Dmitry Baryshkov wrote:
> On Tue, Mar 31, 2026 at 05:11:43AM +0200, Marek Vasut wrote:
> > On 3/31/26 3:22 AM, Dmitry Baryshkov wrote:
> > > On Tue, 31 Mar 2026 at 00:07, Marek Vasut <marek.vasut@xxxxxxxxxxx> wrote:
> > > > On 3/30/26 3:25 PM, Dmitry Baryshkov wrote:
> > > > > Waveshare have a serie of DSI panel kits with the DPI or LVDS panel
> > > > > being attached to the DSI2DPI or DSI2LVDS bridge. Commit 80b0eb11f8e0
> > > > > ("dt-bindings: display: panel: Add waveshare DPI panel support")
> > > > > described two of them in the bindings and commit 46be11b678e0
> > > > > ("drm/panel: simple: Add Waveshare 13.3" panel support") added
> > > > > definitions for one of those panels. Add support for the rest of them.
> > > > Can we by any chance use the icn6211 driver in tree for this ?
> > >
> > > As far as I can see, no. Waveshare kits have an extra ASIC in front of
> > > ICN6211 / ICN6202, which completely hides all programming. So far the
> > > interface is really better expressed by the waveshare,dsi2dpi /
> > > dsi2lvds: this way, even if they decide to change the actual
> > > implementation (like they did for DPI -> LVDS), we won't have to worry
> > > about it for as long as their programming interface remains stable.
> > Hmmm, I've seen this before, but I don't think this is extra ASIC. The
> > ICN6211 pulls its register settings from EEPROM, does it not ?
>
> The kits that I have at hand don't have I2C EEPROMs. They have 25Q8
> QSPI. Also note that neither ICN6211 nor ICN6202 datasheets describe I2C
> master interface. It is defined as a purely I2C slave.
>
> The kits have WSVTH01 chip (CPLD?) and 25Q8 QSPI NOR. I assume the
> bridge settings are loaded from by the WSVTH01 and programmed into the
> ICN bridge.
>
> > But no matter how the ICN loads its configuration, this is not waveshare
> > specific. I have another display from another manufacturer here which is
> > also ICN6211 that is preprogrammed. Can we instead have some generic-dsi
> > display , because I don't think these proprogrammed DSI displays are going
> > to be only ICN6211 based and only made by waveshare ?
>
> If it was just about the bridge config, I would completely agree with
> you. However if you check the waveshare-dsi.c, you'd notice that it is
> not directly related to either of ICN bridges. It controls backlight
> and panel regulators.
Oh ok, this part, I understand.