[U-Boot] [PATCH v5 05/11] exynos: dts: Adjust device tree files for U-Boot

[Simon Glass]

Hi Tom,

On 30 July 2014 09:34, Simon Glass <sjg at chromium.org> wrote:
> Hi Tom,
>
> On 28 July 2014 21:27, Tom Rini <trini at ti.com> wrote:
>> On Mon, Jul 28, 2014 at 06:11:32AM -0600, Simon Glass wrote:
>>
>>> The pinctrl bindings used by Linux are an incomplete description of the
>>> hardware. It is possible in most cases to determine the register address
>>> of each, but not in all cases. By adding an additional property we can
>>> fix this, and avoid adding a table to U-Boot for every single Exynos
>>> SOC.
>>
>> So here's my fear..
>>
>> [snip]
>>> @@ -49,7 +57,7 @@
>>>       i2c at 12ca0000 {
>>>               #address-cells = <1>;
>>>               #size-cells = <0>;
>>> -             compatible = "samsung,s3c2440-i27c";
>>> +             compatible = "samsung,s3c2440-i2c";
>>>               reg = <0x12CA0000 0x100>;
>>>               interrupts = <0 60 0>;
>>>       };
>>
>> Except for the above (what's going on? pulling in a typo fix from
>> upstream?) they're legal "regular" non-U-Boot-prefixed changes.  Are
>> they going back into the master copy in Linux?
>
> Oops I missed this email. The typo is just my mistake - we don't need
> this change and the typo is in the previous patch.
>
>>
>>> diff --git a/arch/arm/dts/exynos5420-pinctrl.dtsi b/arch/arm/dts/exynos5420-pinctrl.dtsi
>>> index b3e63d1..df31f37 100644
>>> --- a/arch/arm/dts/exynos5420-pinctrl.dtsi
>>> +++ b/arch/arm/dts/exynos5420-pinctrl.dtsi
>>> @@ -13,6 +13,18 @@
>>>  */
>>>
>>>  / {
>>> +     /* Replicate the ordering of arch/arm/include/asm/arch-exynos/gpio.h */
>>> +     pinctrl at 14010000 {
>>> +     };
>>> +     pinctrl at 13400000 {
>>> +     };
>>> +     pinctrl at 13410000 {
>>> +     };
>>> +     pinctrl at 14000000 {
>>> +     };
>>> +     pinctrl at 03860000 {
>>> +     };
>>
>> So this isn't going to head back to Linux, clearly...
>>
>> Is there some way we can contain our changes under includes perhaps?
>
> I hope that this one could go away, since the order of GPIOs doesn't
> ultimately matter. At present we assume a particular order due to the
> numbering of GPIOs. But once we move to named GPIOs in the device tree
> we can drop this ordering patch.
>
> In general, yes we could create a new include file for the U-Boot
> device tree additions.

Update: I took a look at the includes. I can create a new file, like
arch/arm/dts/exynos4210-pinctrl.dtsi which I include from
arch/arm/dts/exynos4210.dtsi. But I think I will still need to modify
arch/arm/dts/exynos4210.dtsi. The alternative is to put the changes in
something like exynos4210-u-boot.dtsi and include those in every board
file that uses that include.

This needs to be done for each of the 4/5 SoCs.

>
> We might be able to send these up to the kernel as they are pretty
> harmless and do describe the hardware. Perhaps the kernel people will
> push back on the basis that they are unnecessary for the kernel. I'm
> not sure. What do you think?

The good news is that I think my changes fit within the binding
definition so they may be accepted eventually.

Regards,
Simon