efeeaefe - drm: Add support for the LogiCVC display controller

Fri, 20 May 2022 14:15:55 +0000

drm: Add support for the LogiCVC display controllerIntroduces a driver for the LogiCVC display controller, a programmablelogic controller optimized for use in Xilinx Zynq-7000 SoCs and otherXilinx FPGAs. The controller is mostly configured at logic synthesistime so only a subset of configuration is left for the driver tohandle.The following features are implemented and tested:- LVDS 4-bit interface;- RGB565 pixel formats;- Multiple layers and hardware composition;- Layer-wide alpha mode;The following features are implemented but untested:- Other RGB pixel formats;- Layer framebuffer configuration for version 4;- Lowest-layer used as background color;- Per-pixel alpha mode.The following features are not implemented:- YUV pixel formats;- DVI, LVDS 3-bit, ITU656 and camera link interfaces;- External parallel input for layer;- Color-keying;- LUT-based alpha modes.Additional implementation-specific notes:- Panels are only enabled after the first page flip to avoid flashing a white screen.- Depth used in context of the LogiCVC driver only counts color components to match the definition of the synthesis parameters.Support is implemented for both version 3 and 4 of the controller.With version 3, framebuffers are stored in a dedicated contiguousmemory area, with a base address hardcoded for each layer. This requiresusing a dedicated CMA pool registered at the base address and tweaking afew offset-related registers to try to use any buffer allocated fromthe pool. This is done on a best-effort basis to have the hardware copewith the DRM framebuffer allocation model and there is no guaranteethat each buffer allocated by GEM CMA can be used for any layer.In particular, buffers allocated below the base address for a layer areguaranteed not to be configurable for that layer. See the implementation oflogicvc_layer_buffer_find_setup for specifics.Version 4 allows configuring each buffer address directly, whichguarantees that any buffer can be configured.Signed-off-by: Paul Kocialkowski Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20220520141555.1429041-2-paul.kocialkowski@bootlin.com List of files: /linux-6.15/drivers/gpu/drm/logicvc/Makefile

Changes in Makefile

efeeaefe - drm: Add support for the LogiCVC display controller