[U-Boot] [RFC PATCH v2 00/11] SF: Migrate to Linux SPI NOR framework

Jagan Teki
2018-12-06T17:14:00Z

On Tue, Dec 4, 2018 at 5:56 PM Vignesh R <vigneshr@ti.com> wrote:
>
> U-Boot SPI NOR support (sf layer) is quite outdated as it does not
> support 4 byte addressing opcodes, SFDP table parsing and different types of
> quad mode enable sequences. Many newer flashes no longer support BANK
> registers used 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 isn't 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 easier.

We(someone) has proposed this sync before, but we(at-least I) rely on
implementing via DM not direct sync to Linux. ofcourse other
subsystems might have doing this but I literally don't propose to do
that, since it may fire the u-boot implementation in future.

If you really get things up further, try to check this DM based
spi-nor here[1] and lets discuss on u-boot point-of-view. I've paused
this because of non-dm code, but I'm thinking we even re-change this
to fit MTD driver-model (this is my TODO, once spi dm migration done).

[1] http://git.denx.de/?p=u-boot-spi.git;a=shortlog;h=refs/heads/next-working