[U-Boot] [RFC PATCH 0/6] SF: Migrate to Linux SPI NOR framework

[Stefan Roese]

On 28.11.18 18:26, Vignesh R wrote:
> U-Boot SPI NOR support (sf layer) is quite outdated as it does not
> support 4 byte addressing opcodes, SFDP table and different types of
> quad mode enable sequences. Many newer flashes no longer support BANK
> registers use by sf layer to a access >16MB space.
> Also, many SPI controllers have special MMIO interfaces which provide
> accelerated read/write access but require knowledge of flash parameters
> to make use of it. Recent spi-mem layer provides a way to support such
> flashes but sf layer isnt using that.
> This patch series syncs SPI NOR framework from Linux v4.19. It also adds
> spi-mem support on top.
> So, we gain 4byte addressing support and SFDP support. This makes
> migrating to U-Boot MTD framework very easy.
> 
> Tested with few Spansion, micron and macronix flashes with TI's dra7xx,
> k2g, am43xx EVMs. I dont have access to flashes from other vendors. So,
> I would greatly appreciate testing on other platforms.
> 
> This is a RFC, if this approach if fine with the community and get an
> early feedback. Based on the response, I plan to post
> official series with better splitting of patches, removing all dead code
> and fixing up any checkpatch errors.
> 
> [1] https://github.com/r-vignesh/u-boot.git  branch: spi-nor-mig

Thank you very much for working on this. I tested this patchset on
my MIPS Linkit board with the 4-byte factory strapped Macronix
mx25l25635e/f. It works like a charm. 4-Byte mode is detected /
enabled and I can access the complete SPI flash. So please go ahead
with this patchset. I'll review and test a new patchset version,
once its ready.

With this, my previous implementation of the 4-byte mode detection
can be dropped [1].

Thanks,
Stefan

[1] https://patchwork.ozlabs.org/patch/982525/