Re: [PATCH 4/6] riscv: dts: spacemit: enable QSPI and add SPI NOR on Milk-V Jupiter

[Aurelien Jarno <aurelien@aurel32.net>]

Hi Yixun,

On 2026-03-24 17:02, Yixun Lan wrote:
> Hi Aurelien,
> 
> On 21:28 Sun 22 Mar     , Aurelien Jarno wrote:
> > Add the QSPI controller node for the Milk-V Jupiter board and describe
> > the attached SPI NOR flash (GD25Q64E).
> > 
> > The flash supports a frequency up to 133MHz (80 MHz for reads), and the
> > SoC supports a frequency up to 104 MHz. However tests have shown that
> > the flash is not reliably detected above 26.5 MHz, consistent with
> > frequency used in the vendor kernel. Therefore, use this frequency.
> > 
> ..
> > The m25p,fast-read properties is taken from the vendor kernel.
> > 
> So long as this is verified and works fine on board?

Yes, it's works. And the datasheet also mentions fast read being 
supported.

> > Add a corresponding flash partition layout, matching the layout and the
> > names used in the vendor U-Boot.
> > 
> ..
> > Also add the bootph-pre-ram property to make the device tree usable by
> > early firmware/bootloaders without modification, as U-Boot is stored on
> > this NOR flash.
> Is the dtb file actually used by U-Boot? I'd highly doubt about this,
> if not the case or has not been tested, I'd suggest then not to add
> this property..

It is currently not used by U-Boot, currently SPL support is not 
available, but patches have been posted to added it. I just wanted to 
anticipate the addition of the Milk-V Jupiter board in U-boot, but if 
that hurt, i can remove it (or you can removed it when merging).

Regards
Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                     http://aurel32.net