[PATCH] arm64: dts: add all hi6220 uart nodes

[Rob Herring]

On Wed, Sep 30, 2015 at 1:12 PM, Tyler Baker <tyler.baker at linaro.org> wrote:
> On 30 September 2015 at 10:31, Mark Brown <broonie at kernel.org> wrote:
>> On Wed, Sep 30, 2015 at 10:24:56AM +0200, Arnd Bergmann wrote:
>>> On Tuesday 29 September 2015 13:29:12 Tyler Baker wrote:
>>
>>> >         aliases {
>>> >                 serial0 = &uart0;
>>> > +               serial1 = &uart1;
>>> > +               serial2 = &uart2;
>>> > +               serial3 = &uart3;
>>> > +               serial4 = &uart4;
>>> >         };
>>
>>> In the changelog you mention "both uarts", but here you have five of them.
>>> Are they all accessible on the connector? If not, only provide aliases
>>> for the ones that are, using numbering that makes most sense for given
>>> how one would use the board.
>
> Thanks for the comment Arnd. Mark's comment below is correct, there
> are only two UARTs accessible on the LS connection in addition to the
> one on the board (solder pad).
>
> Is the following definition any clearer?
>
> serial0 = &uart0; // Onboard UART0
> serial1 = &uart2; // LS expansion UART0
> serial2 = &uart3; // LS expansion UART1

Yes, but use C style comments.

What about the BT UART?

>
> If so, I'll respin this patch.
>
>> Unless I'm missing something there's only two UARTs brought out on the
>> low speed expansion connector (in addition to the one on the solder pads
>> which is currently supported).  We should also adjust the console
>> default to match whatever one of the low speed expansion connector UARTs
>> is being used by the bootloader.
>
> Your not missing anything, I should not have added the additional
> aliases, it is confusing, will remove. The UART boards by default come
> configured to use UART1 on the LS connector.

Also, the console default should be set in chosen stdout-path so we
can move away from having to set it on the kernel command line. Then
the aliases don't matter so much, but there may be some work to do to
setup a getty correctly.

> + Peter as he has been submitting u-boot patches recently for the HiKey.
>
> Obviously, both UEFI and u-boot can be configured to use either UART,
> and at the moment u-boot defaults to using the on board UART. Whereas
> UEFI is using UART1 on the LS connector. I'm fine with switching the
> console default to use the UART1 on the LS connector as long as there
> is agreement to do so.

BTW, u-boot can output to multiple serial ports. I think I gave Peter
details on how to do it.

Rob