[U-Boot] [PATCH 0/8] arm: ls1021atwr: Convert to driver model and enable serial support

[Stefan Agner]

On 2016-01-07 01:22, Bin Meng wrote:
> Hi Alison,
> 
> On Thu, Jan 7, 2016 at 2:19 PM, Huan Wang <alison.wang at nxp.com> wrote:
>> Hi, Bin,
>>
>>> On Thu, Jan 7, 2016 at 2:01 PM, Huan Wang <alison.wang at nxp.com> wrote:
>>> > Hi, Bin,
>>> >
>>> >> On Wed, Jan 6, 2016 at 1:31 PM, Huan Wang <alison.wang at nxp.com> wrote:
>>> >> > Hi,
>>> >> >
>>> >> >         I tested this set on my LS1021ATWR board. NOR boot using
>>> >> > DUART
>>> >> as serial output is ok. But NOR boot using LPUART as serial output
>>> >> failed. How about your test result?
>>> >> >
>>> >>
>>> >> Yes, I tested NOR boot using DUART or LPUART. Both boot. I suspect
>>> >> you forgot to update the RCW for LPUART, or change the jumper setting
>>> >> (J19,
>>> >> J20) to route the LPUART signal.
>>> >>
>>> > [Alison Wang] I updated the RCW for LPUART and changed the jumper
>>> > setting (J19, J20). Without this set, NOR boot using LPUART is ok. But
>>> > after adding this set, NOR boot using LPUART failed.
>>> >
>>>
>>> That's strange. Can you please send your build instructions? Did you
>>> program the u-boot-dtb.bin (not u-boot.bin anymore) to the NOR?
>>>
>> [Alison Wang] My build instructions are,
>>
>> make ARCH=arm ls1021atwr_nor_lpuart_defconfig
>> make
>>
>> Yes. I programmed u-boot-dtb.bin to NOR flash.
>>
> 
> Oh, it turns out the last thing to suspect is the /chose node :)
> 
> See comments in patch#8 in this series
> (http://patchwork.ozlabs.org/patch/561859/)
> 
>   chosen {
> + /*
> + * With ls1021atwr_nor_lpuart_defconfig configuration,
> + * this needs to be changed to &lpuart0.
> + */
>   stdout-path = &uart0;
>   };
> 
> I was wondering whether I should introduce another separate dts file
> for this LPUART configuration, something like ls1021a-twr_lpuart.dts,
> but I felt it's quite some duplication thus I chose to just add some
> comments under the /chosen node in the original dts file.

How about:
ls1021a-twr.dts => ls1021a-twr.dtsi

And include that from
ls1021a-twr-uart.dts
ls1021a-twr-lpuart.dts
and add the /chosen node to those files.

--
Stefan