[U-Boot] [PATCH 1/3] ARM: Tegra: FDT: Add USB support for T20/T30/T114

[Stephen Warren]

On 05/03/2013 05:07 AM, Jim Lin wrote:
> On Fri, 2013-05-03 at 03:10 +0800, Stephen Warren wrote:
>> On 04/29/2013 03:21 AM, Jim Lin wrote:
>>> Add DT node for USB function.
>>
>>> diff --git a/arch/arm/dts/tegra114.dtsi b/arch/arm/dts/tegra114.dtsi
>>
>>> +/* This table has USB timing parameters for each Oscillator frequency we
>>> + * support. There are four sets of values:
...
>>> +	usbparams at 3 {
>>> +		compatible = "nvidia,usbparams";
>>> +		osc-frequency = <26000000>;
>>> +		params = <0x3c0 0x1a 0x00 0xc 2  0x04 0x66 0x09 0xfe  0xfde8 0xb>;
>>> +	};
>>
>> None of the above should be present; this is SoC-specific information
>> and should be part of the USB driver itself. There's no benefit to
>> putting the information into DT just to parse it back out into the same
>> tables that the driver could have contained in the first place.
>
> Parameters are not completely same for T20, T30, and T114.
> Putting over dt file is for expanding on future chips.

The driver itself is going to need to change anything in all likelihood,
so there's no point attempting to put the parameters somewhere else to
avoid changing the driver.

Even ignoring all that, the USB DT binding for Tegra is already defined,
and does not include this information, so it must be in the driver.

...
>> The bindings here don't match the kernel. Please make sure they do.
>> This patch only touches 2 board files: Cardhu and Dalmore. Will USB
>> support on other boards continue to work without any DT changes?
>> Existing functionality can't be broken. I'd expect to see a bunch more
>> DT files edited here.
>
> For T20, I only have Seaboard and Harmony platforms.
> For other T20 platforms, I may blindly add USB support as you suggested,
> is that okay?

Yes, please update all Tegra boards so that nothing breaks. For boards
you don't have, others can perform the testing once you've posted the
patches.