[PATCH 0/2] staging: mtd: Support for GigaDevice SPI NAND flash

[Brian Norris]

On Thu, Nov 06, 2014 at 03:17:10PM -0300, Ezequiel Garcia wrote:
> How about picking Sourav's v2 as a starting point:
> 
> http://lists.infradead.org/pipermail/linux-mtd/2013-July/047434.html

Completely irrelevant, but I found this amusing in that patch, a few
lines into spinand.h:

+/bin/bash: 4: command not found

:)

> And then try to use that to support Micron's MT29F and Gigadevice's GD5F ?
> 
> Brian: Any ideas or suggestion on how to proceed?

I'm not opposed to trying to build a proper SPI-NAND framework. But the
linked v2 patch doesn't provide much to start from. It barely handles
anything that is specific to SPI-NAND (pushing the details out to a
flash-specific driver), and it doesn't address what I think the biggest
question is: how similar will the various SPI-NAND implementations be?
I've talked with a few flash vendors and seen that there were some
growing pains with developing a first generation de-facto standard, so
there is bound to be a bit of incompatibility if we try to support the
earliest examples, but it seemed like there was some effort to keep
things consistent across different manufacturers. I don't know the
progress of any standardization effort there.

Anyway, I think we really should look at whether any of the
identification and command sequencing details can be abstracted into a
drivers/mtd/spinand/spinand.c, with client drivers mostly handling the
transport protocol differences (e.g., interfacing with the SPI layer,
similar to what m25p80.c does for SPI NOR).

I don't have any time to create such a framwork on my own, but I may be
able to spare some limited resources for reviewing others' work. I'd
really like to see some efforts from a few interested reviewers, as I
haven't figured out how to squeeze more hours into my day yet.

BTW, has there been any progress on whatever TODO items landed
mt29f_spinand in staging in the first place?

Brian