Re: [PATCH v3 2/7] dt-bindings: bus: Add binding for the Allwinner MBUS controller
From: Robin Murphy <robin.murphy@arm.com>
Date: 2019-02-12 18:53:11
Also in:
dri-devel, linux-devicetree
On 11/02/2019 15:02, Maxime Ripard wrote:
quoted hunk ↗ jump to hunk
The MBUS controller drives the MBUS that other devices in the SoC will use to perform DMA. It also has a register interface that allows to monitor and control the bandwidth and priorities for masters on that bus. Signed-off-by: Maxime Ripard <redacted> --- Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt | 36 +++++++- 1 file changed, 36 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txtdiff --git a/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt b/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt new file mode 100644 index 000000000000..e72b7ac9e359 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/sunxi/sunxi-mbus.txt@@ -0,0 +1,36 @@ +Allwinner Memory Bus (MBUS) controller + +The MBUS controller drives the MBUS that other devices in the SoC will +use to perform DMA. It also has a register interface that allows to +monitor and control the bandwidth and priorities for masters on that +bus. + +Required properties: + - compatible: Must be one of: + - allwinner,sun5i-a13-mbus + - reg: Offset and length of the register set for the controller + - clocks: phandle to the clock driving the controller + - dma-ranges: see booting-without-of.txt
Nit: this is a standard property in DTSpec, so it's probably better to refer to that rather than Linux-specific documentation. Robin.
+ - #interconnect-cells: Must be one, with the argument being the MBUS
+ port ID
+
+Each device having to perform their DMA through the MBUS must have the
+interconnects and interconnect-names properties set to the MBUS
+controller and with "dma" as the interconnect name.
+
+Example:
+
+mbus: dram-controller@1c01000 {
+ compatible = "allwinner,sun5i-a13-mbus";
+ reg = <0x01c01000 0x1000>;
+ clocks = <&ccu CLK_MBUS>;
+ dma-ranges = <0x00000000 0x40000000 0x20000000>;
+ #interconnect-cells = <1>;
+};
+
+fe0: display-frontend@1e00000 {
+ compatible = "allwinner,sun5i-a13-display-frontend";
+ ...
+ interconnects = <&mbus 19>;
+ interconnect-names = "dma";
+};_______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel