On Wed Nov 26, 2025 at 6:35 PM CET, Kory Maincent (TI.com) wrote:

Migrate CRTC mode configuration to use standard DRM bus flags in
preparation for removing the tilcdc_panel driver and its custom
tilcdc_panel_info structure.

Add support for DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE and
DRM_BUS_FLAG_SYNC_DRIVE_NEGEDGE flags to control pixel clock and sync
signal edge polarity, while maintaining backward compatibility with the
existing tilcdc panel info structure.

Simplify several hardware parameters by setting them to fixed defaults
based on common usage across existing device trees:
- DMA burst size: 16 (previously configurable via switch statement)
- AC bias frequency: 255 (previously panel-specific)
- FIFO DMA request delay: 128 (previously panel-specific)

These parameters show no variation in real-world usage, so hardcoding
them simplifies the driver without losing functionality.

Preserve FIFO threshold configurability by adding a new "fifo-threshold"
device tree property at the display controller level, as this parameter
varies across different display configurations in existing device trees.

Signed-off-by: Kory Maincent (TI.com) <kory.maincent@bootlin.com>

Apart from the "fifo-threshold" property, which as discussed should instead
be inferred from the compatible, the patch looks good. I checked the values
which are being removed and they have all the same value in the code
defaults and all in-tree dts files.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com