Hi Christoph Hellwig,
This is the patchset. for your reference.
thanks,
On Mon, Jun 8, 2020 at 4:30 PM <dillon.minfei@xxxxxxxxx> wrote:
>
> From: dillon min <dillon.minfei@xxxxxxxxx>
>
> 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 <dillon.minfei@xxxxxxxxx>
> ---
> 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
>
