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
