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Linus Walleij authored
The Versatile Express has 8 MB of dedicated video RAM (VRAM) on the motherboard, which is what we should be using for the PL111 if available. On this platform, the memory backplane is constructed so that only this memory will work properly with the CLCD on the motherboard, using any other memory area just gives random snow on the display. The CA9 Versatile Express also has a PL111 instance on its core tile that can address all memory, and this does not have the restriction. The memory is assigned to the device using the memory-region device tree property and a "shared-dma-pool" reserved memory pool like this: reserved-memory { #address-cells = <1>; #size-cells = <1>; ranges; vram: vram@48000000 { compatible = "shared-dma-pool"; reg = <0x48000000 0x00800000>; no-map; }; }; clcd@1f000 { compatible = "arm,pl111", "arm,primecell"; (...) memory-region = <&vram>; }·; Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Mali DP Maintainers <malidp@foss.arm.com> Reviewed-by: Eric Anholt <eric@anholt.net> Tested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20180502134719.8388-2-linus.walleij@linaro.org
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