[PATCH v2 3/4] dt-bindings: mtd: macronix,mx25l12833f: add SPI-NOR chip

[Erez]

On Mon, 1 Jul 2024 at 12:15, Tudor Ambarus <tudor.ambarus at linaro.org> wrote:
>
>
>
> On 7/1/24 10:46 AM, Erez wrote:
> > When using mx25l12805d, we do not read SFDP.
> > As it uses the no-SFDP flags.
> > When using mx25l12833f hardware with mx25l12805d driver, it did not
> > try to read the SFDP.
> > Yet mx25l12833f does have SFDP, when I remove the no-SFDP flags, the
> > driver fetch the SFDP.
> >
> > Secondly SFDP does not contain OTP information.
> >
> > mx25l12805d has two OTP regions of 128 KiB and 384 KiB (yes asymmetric).
> > While mx25l12833f has two OTP regions of 512 KiB.
> >
> > How do we handle it?
>
> You would first try to parse SFDP and initialize the flash based on
> SFDP. If there's no SFDP then you fallback to the flags declared at
> flash declaration. Esben had a try recently, see [1]. I don't know if
> there's any progress in that direction.
>
> Also, you haven't mentioned anything about the testing. Do you have the
> flash?
>
> [1]
> https://lore.kernel.org/linux-mtd/20240603-macronix-mx25l3205d-fixups-v2-0-ff98da26835c@geanix.com/

Looking at "mtd: spi-nor: macronix: workaround for device id re-use"
I guess it can be applied to all Macronix devices.
Adding something like the following in macronix_nor_default_init():

if (info>no_sfdp_flags)
    info>no_sfdp_flags |= SPI_NOR_TRY_SFDP

It seems Macronix did many reuse of IDs.
I saw it with "mx25l12833f" reusing "mx25l12805d".
And Esben saw it with MX25L3233F reusing "MX25L3205D".

The only thing I notice is the flash using the same size.
A sort of "backward" compatible.

Erez