dt-bindings: allow child nodes inside the Tegra BPMP

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.
Update the binding to describe how the BPMP supports this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
master
Stephen Warren 8 years ago committed by Tom Warren
parent 7b9cb49405
commit 390ae57c76
  1. 23
      doc/device-tree-bindings/firmware/nvidia,tegra186-bpmp.txt

@ -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>;
i2c {
compatible = "...";
...
};
};

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