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U-Boot SPI NOR support (sf layer) is quite outdated as it does not support 4 byte addressing opcodes, SFDP table and different types of quad mode enable sequences.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