On Tue, Oct 13, 2026 at 01:11:58PM +0200, Laurent Pinchart wrote: > On Tue, Oct 13, 2026 at 11:06:31AM +0200, Francesco Dolcini wrote: > > On Mon, Oct 12, 2026 at 06:40:54PM +0200, Laurent Pinchart wrote: > > > On Mon, Oct 12, 2026 at 04:25:22AM -0300, Leonardo Costa wrote: > > > > This series adds a device tree overlay that enables the VGA output on > > > > Apalis > > > > iMX6, which is driven from a parallel RGB interface passing through a > > > > non-programmable video DAC. > > > > > > > > The video DAC is a simple resistor network gated by an active-low > > > > data-enable signal. For the bridge to work properly, this series also > > > > changes the following in the dt-bindings and simple-bridge driver: > > > > > > > > - dt-bindings: Add a new compatible for the bridge in the simple-bridge > > > > binding. This is necessary because the existing dumb-vga-dac > > > > compatible > > > > doesn't describe a data-enable signal polarity. > > > > > > > > - simple-bridge: Add the VGA bridge match-table entry and timings > > > > struct, setting the DRM_BUS_FLAG_DE_LOW flag for the bridge. > > > > > > Is there schematics available anywhere ? That would help reviewing the > > > series ? > > > > This circuit is on the SoM, and the SoM schematics are > > confidential and not generally available. > > > > I tried to extract as ascii art the relevant circuit, hope it helps > > Thank you, it makes things clearer. > > The circuit seems fairly generic. Wouldn't it be better to add an > optional property ot the dumb-vga-dac instead of a new compatible string > specific to Apalis ?
We discussed this internally and we were not 100% sure, so we decided to go with this proposal that seemed easier and less controversial. With that wrote, I let Leonardo comment on the pro/cons of the two approaches. Francesco
