@@ -38,6 +38,24 @@ implemented by this node:
 - .../reset/reset.txt
 - <dt-bindings/reset/tegra186-reset.h>
 
+The BPMP implements some services which must be represented by separate nodes.
+For example, it can provide access to certain I2C controllers, and the I2C
+bindings represent each I2C controller as a device tree node. Such nodes should
+be nested directly inside the main BPMP node.
+
+Software can determine whether a child node of the BPMP node represents a device
+by checking for a compatible property. Any node with a compatible property
+represents a device that can be instantiated. Nodes without a compatible
+property may be used to provide configuration information regarding the BPMP
+itself, although no such configuration nodes are currently defined by this
+binding.
+
+The BPMP firmware defines no single global name-/numbering-space for such
+services. Put another way, the numbering scheme for I2C buses is distinct from
+the numbering scheme for any other service the BPMP may provide (e.g. a future
+hypothetical SPI bus service). As such, child device nodes will have no reg
+property, and the BPMP node will have no #address-cells or #size-cells property.
+
 The shared memory bindings for BPMP
 -----------------------------------
 

@@ -78,4 +96,9 @@ bpmp {
 	#clock-cells = <1>;
 	#power-domain-cells = <1>;
 	#reset-cells = <1>;
+
+	bpmp-i2c {
+		compatible = "...";
+		...
+	};
 };