[flashrom] Tagging all EWSR chips correctly (was: [PATCH] spi25.c: Refactor spi_write_status_register helpers.)

[Stefan Tauner]

On Tue, 07 Feb 2012 23:31:50 +0100
Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> wrote:

> Ahem. Once we do the per-region unlock dance, this will be extremely
> painful. We have three choices:
> - Keep that part of the code as is. Not good.
> - Spit out that message for every status register write. Not good.
> - Fix all flash chip definitions. Good, but separate patch.
> How do we proceed?

fixing the stuff that needs fixing, of course.

steve said he might look into it, so this is what has to be done:
i have attached a file containing what seems to be the spi chips
without correctly set feature_bits fields. we need to check the
datasheets for the opcodes needed to enable writing to the status
register. normally this is either WREN (write enable) or EWSR (enable
write status register), or both.
currently we are only interested in the non-volatile bits of the status
register, but there are chips that require another write enable command
for the volatile bits. if anyone creates a spreadsheet, he should
probably note those too if feasible or maybe even add a comment in the
patch.

the field should be added after page_size and either set to:
		.feature_bits	= FEATURE_WRSR_EWSR
or
		.feature_bits	= FEATURE_WRSR_EITHER
if EWSR and WREN are allowed (all other SPI chips are already set
to FEATURE_WRSR_WREN). in the case we encounter a chip that does use
something else a comment should suffice for the time being.

we could also split the work up, if it takes too long otherwise...
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner
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