From: dillon min <[email protected]> To mmap a framebuffer or v4l2 buffer from kernel to userspace on no-mmu platform, we need rely on 'arm_nommu_dma_ops' from arch/arm/mm/dma-mapping-nommu.c , so setup 4M bytes memory reserved for this purpose.
Signed-off-by: dillon min <[email protected]> --- arch/arm/boot/dts/stm32f469-disco.dts | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/arm/boot/dts/stm32f469-disco.dts b/arch/arm/boot/dts/stm32f469-disco.dts index 9397db0c43de..082b24ee81f7 100644 --- a/arch/arm/boot/dts/stm32f469-disco.dts +++ b/arch/arm/boot/dts/stm32f469-disco.dts @@ -65,6 +65,20 @@ reg = <0x00000000 0x1000000>; }; + reserved-memory { + #address-cells = <1>; + #size-cells = <1>; + ranges; + + linux,dma { + compatible = "shared-dma-pool"; + size = <0x400000>; + no-map; + linux,dma-default; + }; + + }; + aliases { serial0 = &usart3; }; -- 2.7.4
