This patch adds the documentation of device tree bindings for the STM32
DMAMUX.
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@xxxxxxxxx>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
---
Version history:
v4:
* Add multi-master ability for STM32 DMAMUX
* Get rid of st,dmamux properties
v3:
* Change compatible to st,stm32h7-dmamux to be mode Soc specific
* Add verbosity in dma-cells
v2:
* Move clock bindings from optional to mandatory one
* Drop channelID bindings as managed dynamically from now on by
DMAMUX driver.
---
---
.../devicetree/bindings/dma/stm32-dmamux.txt | 84 ++++++++++++++++++++++
1 file changed, 84 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/stm32-dmamux.txt
diff --git a/Documentation/devicetree/bindings/dma/stm32-dmamux.txt b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
new file mode 100644
index 0000000..1b893b2
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/stm32-dmamux.txt
@@ -0,0 +1,84 @@
+STM32 DMA MUX (DMA request router)
+
+Required properties:
+- compatible: "st,stm32h7-dmamux"
+- reg: Memory map for accessing module
+- #dma-cells: Should be set to <3>.
+ First parameter is request line number.
+ Second is DMA channel configuration
+ Third is Fifo threshold
+ For more details about the three cells, please see
+ stm32-dma.txt documentation binding file
+- dma-masters: Phandle pointing to the DMA controllers.
+ Several controllers are allowed. Only "st,stm32-dma" DMA
+ compatible are supported.
+
+Optional properties:
+- dma-channels : Number of DMA requests supported.
+- dma-requests : Number of DMAMUX requests supported.
+- resets: Reference to a reset controller asserting the DMA controller
+- clocks: Input clock of the DMAMUX instance.
+
+Example:
+
+/* DMA controller 1 */
+dma1: dma-controller@40020000 {
+ compatible = "st,stm32-dma";
+ reg = <0x40020000 0x400>;
+ interrupts = <11>,
+ <12>,
+ <13>,
+ <14>,
+ <15>,
+ <16>,
+ <17>,
+ <47>;
+ clocks = <&timer_clk>;
+ #dma-cells = <4>;
+ st,mem2mem;
+ resets = <&rcc 150>;
+ dma-channels = <8>;
+ dma-requests = <8>;
+};
+
+/* DMA controller 1 */
+dma2: dma@40020400 {
+ compatible = "st,stm32-dma";
+ reg = <0x40020400 0x400>;
+ interrupts = <56>,
+ <57>,
+ <58>,
+ <59>,
+ <60>,
+ <68>,
+ <69>,
+ <70>;
+ clocks = <&timer_clk>;
+ #dma-cells = <4>;
+ st,mem2mem;
+ resets = <&rcc 150>;
+ dma-channels = <8>;
+ dma-requests = <8>;
+};
+
+/* DMA mux */
+dmamux1: dma-router@40020800 {
+ compatible = "st,stm32h7-dmamux";
+ reg = <0x40020800 0x3c>;
+ #dma-cells = <3>;
+ dma-requests = <128>;
+ dma-channels = <16>;
+ dma-masters = <&dma1 &dma2>;
+ clocks = <&timer_clk>;
+};
+
+/* DMA client */
+usart1: serial@40011000 {
+ compatible = "st,stm32-usart", "st,stm32-uart";
+ reg = <0x40011000 0x400>;
+ interrupts = <37>;
+ clocks = <&timer_clk>;
+ dmas = <&dmamux1 41 0x414 0>,
+ <&dmamux1 42 0x414 0>;
+ dma-names = "rx", "tx";
+};
--
2.7.4
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