Thread (13 messages) 13 messages, 4 authors, 2019-07-26
STALE2519d
Revisions (4)
  1. v1 [diff vs current]
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 current

[PATCH v4 1/8] dt-bindings: stm32: add bindings for ML-AHB interconnect

From: Fabien Dessenne <hidden>
Date: 2019-05-14 08:28:24
Also in: linux-devicetree, linux-remoteproc, lkml
Subsystem: open firmware and flattened device tree bindings, the rest · Maintainers: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

Document the ML-AHB interconnect for stm32 SoCs.

Signed-off-by: Fabien Dessenne <redacted>
---
 .../devicetree/bindings/arm/stm32/mlahb.txt        | 37 ++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/stm32/mlahb.txt
diff --git a/Documentation/devicetree/bindings/arm/stm32/mlahb.txt b/Documentation/devicetree/bindings/arm/stm32/mlahb.txt
new file mode 100644
index 0000000..25307aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/stm32/mlahb.txt
@@ -0,0 +1,37 @@
+ML-AHB interconnect bindings
+
+These bindings describe the STM32 SoCs ML-AHB interconnect bus which connects
+a Cortex-M subsystem with dedicated memories.
+The MCU SRAM and RETRAM memory parts can be accessed through different addresses
+(see "RAM aliases" in [1]) using different buses (see [2]) : balancing the
+Cortex-M firmware accesses among those ports allows to tune the system
+performance.
+
+[1]: https://www.st.com/resource/en/reference_manual/dm00327659.pdf
+[2]: https://wiki.st.com/stm32mpu/wiki/STM32MP15_RAM_mapping
+
+Required properties:
+- compatible: should be "simple-bus"
+- dma-ranges: describes memory addresses translation between the local CPU and
+	   the remote Cortex-M processor. Each memory region, is declared with
+	   3 parameters:
+		 - param 1: device base address (Cortex-M processor address)
+		 - param 2: physical base address (local CPU address)
+		 - param 3: size of the memory region.
+
+The Cortex-M remote processor accessed via the mlahb interconnect is described
+by a child node.
+
+Example:
+mlahb {
+	compatible = "simple-bus";
+	#address-cells = <1>;
+	#size-cells = <1>;
+	dma-ranges = <0x00000000 0x38000000 0x10000>,
+		     <0x10000000 0x10000000 0x60000>,
+		     <0x30000000 0x30000000 0x60000>;
+
+	m4_rproc: m4@10000000 {
+		...
+	};
+};
-- 
2.7.4


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help