arm: stm32h7: Support for the STM32H747I-DISCO board

[Johannes (krjdev) Krottmayer]

Hi Patrice

Thanks for the answer.

On 07.03.22 17:09, Patrice CHOTARD wrote:
>> But there some issues on the website:
>> - According the website, the board has 256Mbit external SDRAM
>>
>> That's not true. There is a 512MBit SDRAM from ISSI mounted.

It's a 256Mbit SDRAM mounted on the board. First looked in the
schematics in the user manual and there are two SDRAM types
(256MBit and 512Bit from ISSI). But unfortunately no notice
which type is really mounted.

Sorry, my mistake.

>> Can I release a patch series here, when my work is done? I don't
>> know if there any interest for other users exists, to add here
>> the support to U-Boot.
> 
> Yes please, it's still useful to get a new STM32 board supported in U-Boot ;-)

Device-Trees:
I would release SoC device-trees for other types in this series too.
Made a base SoC (dtsi) for the STM32H745. The STM32H747 includes this
device-tree as base configuration, because according the TRM, the
STM32H747 has an additional feature, the DSI interface.

Other SoC series:
- STM32H755:
STM32H755 source also STM32H745, because the additional features is
the HASH and the CRYPTO controller.

- STM32H757:
STM32H757 source also STM32H747 because the SoC has also the DSI
interface and the HASH and the CRYPTO controller.

So I would create following SoC device-trees:
stm32h745.dtsi -> This is the base device-tree
stm22h747.dtsi
stm22h755.dtsi
stm32h757.dtsi

Of course also for STM32H747I-DISCO. :)

Okay?

Kind regards,

Johannes K.