[U-Boot] [PATCH 2/3] Tegra30: fdt: Update DT files with I2C info for T30/Cardhu

Stephen Warren swarren at wwwdotorg.org
Wed Jan 2 21:41:21 CET 2013


On 12/21/2012 05:16 PM, Tom Warren wrote:
> Note that T30 does not have a separate/different DVC (power I2C)
> controller like T20 - all 5 I2C controllers are identical, but
> DVC_I2C is still used to designate the controller intended for
> power control (PWR_I2C in the schematics). On Cardhu, it's used
> to access the PMU and EEPROM, as well as the audio codec, temp
> sensor, and fuel gauge devices from the OS.

> diff --git a/arch/arm/dts/tegra30.dtsi b/arch/arm/dts/tegra30.dtsi

> +	tegra_car: clock at 60006000 {
> +		compatible = "nvidia,tegra30-car", "nvidia,tegra20-car";
> +		reg = <0x60006000 0x1000>;
> +		#clock-cells = <1>;
> +	};
> +
> +	clocks {

It'd be nice to keep the DT nodes sorted in the same order they are in
the kernel. There, the rules are that nodes appears in order:

1) Any nodes from /include/d files, in the order they appeared in the
underlying file.

2) Any nodes with a reg property, in order of the address in the reg
property.

3) Any nodes without a reg property, in alphabetical order by node name.

This will allow the U-Boot and kernel DT files to be more easily
compared/diff'd.

The clocks and osc node would usually be part of the board file, not the
SoC file, I believe...

Actually, the clocks "osc" and (later) "clk_32k" don't appear to be used
anywhere; can we just drop their nodes until if/when they are?

> +	i2c at 7000c000 {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		compatible = "nvidia,tegra30-i2c", "nvidia,tegra20-i2c";
> +		reg = <0x7000C000 0x100>;
> +		/* PERIPH_ID_I2C1, CLK_M */
> +		clocks = <&tegra_car 12>;
> +	};

I think we should use lower-case for all hex constants in the DT. Also,
can the properties appear in the same order as in the kernel DT files so
they're easier to compare/diff.

Also, the SoC .dtsi file should have status="disabled" for all the
optionally-used HW modules, and the board files set status="okay" for
those that the board actually uses.


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