[U-Boot] [PATCH 2/7] tegra: fdt: Add extra I2C definitions for U-Boot

[Simon Glass]

Hi Stephen,

On Mon, Dec 26, 2011 at 8:35 PM, Stephen Warren <swarren at nvidia.com> wrote:
> Simon Glass wrote at Monday, December 26, 2011 11:12 AM:
>> Add U-Boot's peripheral ID and pinmux selection to the Tegra20
>> device tree file.
>
>> diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi
> ...
>>               compatible = "nvidia,tegra20-i2c";
>>               reg = <0x7000C000 0x100>;
>>               interrupts = < 70 >;
>> +             u-boot,pinmux = <0>;
>
> That isn't acceptable to me for the same reasons I've outline many
> times before while discussing USB.
>
> At least periph-id can be argued to be related to the HW, but the pinmux
> value is a hack that really has no place in device tree.

Are you sure you have this right? The pinmux is set by the hardware,
since it is the board schematic which determines which SOC pins are
connected to the I2C bus, for example.

There are only a few possible combinations for each port, so I believe
it makes sense to represent these by a number, at least until we find
out what Linux will do.

But if not, what do you propose we do instead?

>
>> +             speed = <100000>;
>
> That's already defined as "clock-frequency" in the Linux kernel.

OK thanks. I must be chasing a moving target here, as I got this
device tree from the -next branch of the kernel only a few weeks ago.
Can you please point me to the latest definition for i2c?

Regards,
Simon

>
>> +             u-boot,periph-id = <12>;        // PERIPH_ID_I2C1
>
> --
> nvpublic
>