[RFC] (early draft) dt: Linux dt usage model documentation

[Shawn Guo]

On Mon, Jun 13, 2011 at 07:32:15AM -0600, Grant Likely wrote:
[...]
> +About now is a good time to lay out an example.  Here is part of the
> +device tree for the NVIDIA Tegra board.
> +
> +/{
> +	compatible = "nvidia,harmony", "nvidia,tegra250";
> +	#address-cells = <1>;
> +	#size-cells = <1>;
> +	interrupt-parent = <&intc>;
> +
> +	chosen { };
> +	aliases { };
> +
> +	memory {
> +		device_type = "memory";
> +		reg = <0x00000000 0x40000000>;
> +	};
> +
> +	soc {
> +		compatible = "nvidia,tegra250-soc", "simple-bus";
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges;
> +
> +		intc: interrupt-controller at 50041000 {
> +			compatible = "nvidia,tegra250-gic";
> +			interrupt-controller;
> +			#interrupt-cells = <1>;
> +			reg = <0x50041000 0x1000>, < 0x50040100 0x0100 >;
> +		};
> +
> +		serial at 70006300 {
> +			compatible = "nvidia,tegra250-uart";
> +			reg = <0x70006300 0x100>;
> +			interrupts = <122>;
> +		};
> +
> +		i2s-1: i2s at 70002800 {

It seem dtc does not compile the label name "i2s-1".  Instead,
"i2s_1" seems good.

> +			compatible = "nvidia,tegra250-i2s";
> +			reg = <0x70002800 0x100>;
> +			interrupts = <77>;
> +			codec = <&wm8903>;
> +		};
> +
> +		i2c at 7000c000 {
> +			compatible = "nvidia,tegra250-i2c";
> +			#address-cells = <1>;
> +			#size-cells = <1>;

#size-cells should be 0 ...

> +			reg = <0x7000c000 0x100>;
> +			interrupts = <70>;
> +
> +			wm8903: codec at 1a {
> +				compatible = "wlf,wm8903";
> +				reg = <0x1a>;

... Otherwise, reg needs a size here.

> +				interrupts = <347>;
> +			};
> +		};
> +	};
> +
> +	sound {
> +		compatible = "nvidia,harmony-sound";
> +		i2s-controller = <&i2s-1>;
> +		i2s-codec = <&wm8903>;
> +	};
> +};
> +

-- 
Regards,
Shawn