Re: [PATCH 1/3] Docs: dt: add generic MSI bindings

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 07/23/2015 09:52 AM, Mark Rutland wrote:
[...]
+MSI clients
+===========
+
+MSI clients are devices which generate MSIs. For each MSI they wish to
+generate, the doorbell and payload may be configured, though sideband
+information may not be configurable.
+
+Required properties:
+--------------------
+
+- msi-parent: A list of phandle + msi-specifier pairs, one for each MSI
+  controller which the device is capable of using.
+

We say here that "msi-parent" consists of pairs ...

+  This property is unordered, and MSIs may be allocated from any combination of
+  MSI controllers listed in the msi-parent property.
+
+  If a device has restrictions on the allocation of MSIs, these restrictions
+  must be described with additional properties.
+
+  When #msi-cells is non-zero, busses with an msi-parent will require
+  additional properties to describe the relationship between devices on the bus
+  and the set of MSIs they can potentially generate.
+
+
+Example
+=======
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	msi_a: msi-controller@a {
+		reg = <0xa 0xf00>;
+		compatible = "vendor-a,some-controller";
+		msi-controller;
+		/* No sideband data, so #msi-cells omitted */
+	};
+
+	msi_b: msi-controller@b {
+		reg = <0xb 0xf00>;
+		compatible = "vendor-b,another-controller";
+		msi-controller;
+		/* Each device has some unique ID */
+		#msi-cells = <1>;
+	};
+
+	msi_c: msi-controller@c {
+		reg = <0xb 0xf00>;
+		compatible = "vendor-b,another-controller";
+		msi-controller;
+		/* Each device has some unique ID */
+		#msi-cells = <1>;
+	};
+
+	dev@0 {
+		reg = <0x0 0xf00>;
+		compatible = "vendor-c,some-device";
+
+		/* Can only generate MSIs to msi_a */
+		msi-parent = <&msi_a>;


My device-tree syntax foo is a little rusty, but doesn't "msi-parent" need a pair of elements? This has only the phandle.

+	};
+
+	dev@1 {
+		reg = <0x1 0xf00>;
+		compatible = "vendor-c,some-device";
+
+		/*
+		 * Can generate MSIs to either A or B.
+		 */
+		msi-parent = <&msi_a>, <&msi_b 0x17>;


... same here, ...

+	};
+
+	dev@2 {
+		reg = <0x2 0xf00>;
+		compatible = "vendor-c,some-device";
+		/*
+		 * Has different IDs at each MSI controller.
+		 * Can generate MSIs to all of the MSI controllers.
+		 */
+		msi-parent = <&msi_a>, <&msi_b 0x17>, <&msi_c 0x53>;

... and here

+	};
+};

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux