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

[Simon Glass]

Hi,

On 10 January 2016 at 20:10, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Thu, Jan 7, 2016 at 5:22 PM, Bin Meng <bmeng.cn at gmail.com> 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.
>>
>> I've done the PCI UART support on the Crown Bay before using the same
>> way. Simon, do you have some better way to handle this?
>
> Alison has tested this series on her board. I believe the only concern
> is with the lpuart in the /chosen node. Can you comment on this?

It looks OK to me. You could create a separate device tree and put the
common contents in a .dtsi file,. I'm not sure of the trade-offs with
this though.

Regards,
Simon