Hi Geert, Thanks for the feedback.
> -----Original Message----- > From: Geert Uytterhoeven <[email protected]> > Sent: 14 January 2026 12:38 > Subject: Re: [PATCH 10/22] dt-bindings: display: renesas,rzg2l-du: Add > support for RZ/G3E SoC > > Hi Tommaso, > > On Wed, 3 Dec 2025 at 14:42, Tommaso Merciai > <[email protected]> wrote: > > On Wed, Dec 03, 2025 at 09:23:53AM +0100, Krzysztof Kozlowski wrote: > > > On Wed, Nov 26, 2025 at 03:07:22PM +0100, Tommaso Merciai wrote: > > > > The RZ/G3E Soc has 2 LCD controller (LCDC), contain a Frame > > > > Compression Processor (FCPVD), a Video Signal Processor (VSPD), > > > > Video Signal Processor (VSPD), and Display Unit (DU). > > > > > > > > - LCDC0 supports DSI and LVDS (single or dual-channel) outputs. > > > > - LCDC1 supports DSI, LVDS (single-channel), and RGB outputs. > > > > > > > > Add then two new SoC-specific compatible strings 'renesas,r9a09g047-du0' > > > > and 'renesas,r9a09g047-du1'. > > > > > > LCDC0/1 but compatibles du0/du1... > > > > > > What are the differences between DU0 and DU1? Just different > > > outputs? Is the programming model the same? > > > > The hardware configurations are different: these are two distinct hardware > > blocks. > > > > Based on the block diagrams shown in Figures 9.4-2 (LCDC1) and 9.4-1 > > (LCDC0), the only difference concerns the output, but this variation > > is internal to the hardware blocks themselves. > > Therefore, LCDC0 and LCDC1 are not identical blocks, and their > > programming models differ as a result. > > > > In summary, although most of the internal functions are the same, the > > two blocks have output signals connected to different components within the > > SoC. > > This requires different hardware configurations and inevitably leads > > to different programming models for LCDC0 and LCDC1. > > Isn't that merely an SoC integration issue? > Are there any differences in programming LCDC0 or LCDC1 for the common output > types supported by both > (single channel LVDS and 4-lane MIPI-DSI)? Dual LVDS case, dot clock from LCDC0 is used in both LCDC's. Standalone LVDS and DSI the programming flow is same. > > Of there are no such differences, both instances should use the same > compatible value. Then we need to use a property called display-id, to describe the supported output types in bindings, right?? Display-id=0 {LVDS, DSI) Display-id=1 {LVDS, DSI, DPI) Cheers, Biju
