Thread (7 messages) 7 messages, 2 authors, 2018-02-28
STALE3015d REVIEWED: 1 (0M)

[PATCH v2 1/4] ARM: dts: stm32: add DMA memory pool on MCU which embed a cortex-M7

From: Alexandre Torgue <hidden>
Date: 2018-02-28 13:10:55
Also in: linux-devicetree
Subsystem: the rest · Maintainer: Linus Torvalds

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 except stm32f746-disco. Indeed, as stm32f746-disco has
only a 8MB SDRAM and it's tricky to reduce memory used by Kernel.

Reviewed-by: Vladimir Murzin <redacted>
Signed-off-by: Alexandre Torgue <redacted>
diff --git a/arch/arm/boot/dts/stm32746g-eval.dts b/arch/arm/boot/dts/stm32746g-eval.dts
index e3f5a83..92651c3 100644
--- a/arch/arm/boot/dts/stm32746g-eval.dts
+++ b/arch/arm/boot/dts/stm32746g-eval.dts
@@ -58,6 +58,19 @@
 		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 d712260..c526853 100644
--- a/arch/arm/boot/dts/stm32f769-disco.dts
+++ b/arch/arm/boot/dts/stm32f769-disco.dts
@@ -59,6 +59,19 @@
 		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 45e088c..3689e70 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 c7187e1..b9af696 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
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