[PATCH 1/3] ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7

[Alexandre Torgue]

On cortex-M7 MCU, DMA have to use a non cache-able memory area. For this
reason a dedicated memory pool is created for DMA.
This patch creates a DMA memory pool of 1MB of each STM32 MCU which
embeds a cortex-M7 expect stm32f746-disco. Indeed, as stm32f746-disco has
only a 8MB SDRAM and it's tricky to reduce memory used by Kernel.

Signed-off-by: Alexandre Torgue <alexandre.torgue at st.com>

diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index 2d4e717..3f52a7b 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -57,6 +57,19 @@
 		reg = <0xc0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32f769-disco.dts b/arch/arm/boot/dts/stm32f769-disco.dts
index 4463ca1..08699a2 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -57,6 +57,19 @@
 		reg = <0xC0000000 0x1000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc0f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-disco.dts b/arch/arm/boot/dts/stm32h743i-disco.dts
index 79e841d..104545a 100644
--- a/arch/arm/boot/dts/stm32h743i-disco.dts
+++ b/arch/arm/boot/dts/stm32h743i-disco.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart2;
 	};
diff --git a/arch/arm/boot/dts/stm32h743i-eval.dts b/arch/arm/boot/dts/stm32h743i-eval.dts
index 9f0e72c..5bd4b16 100644
--- a/arch/arm/boot/dts/stm32h743i-eval.dts
+++ b/arch/arm/boot/dts/stm32h743i-eval.dts
@@ -57,6 +57,19 @@
 		reg = <0xd0000000 0x2000000>;
 	};
 
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		linux,dma {
+			compatible = "shared-dma-pool";
+			linux,dma-default;
+			no-map;
+			reg = <0xc1f00000 0x100000>;
+		};
+	};
+
 	aliases {
 		serial0 = &usart1;
 	};
-- 
2.7.4