Re: [PATCH v2 00/12] mtd: nand_bbt: introduce independent nand BBT

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Tue, 29 Dec 2015 12:07:50 -0300
Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> wrote:

> On 29 December 2015 at 06:35, Boris Brezillon
> <boris.brezillon@free-electrons.com> wrote:
> > Hi,
> >
> > On Mon, 28 Dec 2015 17:42:50 -0300
> > Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> wrote:
> >
> >> This is looking a lot better, thanks for the good work!
> >>
> >> On 15 December 2015 at 02:59, Peter Pan <peterpansjtu@gmail.com> wrote:
> >> > Currently nand_bbt.c is tied with struct nand_chip, and it makes other
> >> > NAND family chips hard to use nand_bbt.c. Maybe it's the reason why
> >> > onenand has own bbt(onenand_bbt.c).
> >> >
> >> > Separate struct nand_chip from BBT code can make current BBT shareable.
> >> > We create struct nand_bbt to take place of nand_chip in nand_bbt.c.
> >> > Struct nand_bbt contains all the information BBT needed from outside and
> >> > it should be embedded into NAND family chip struct (such as struct nand_chip).
> >> > NAND family driver should allocate, initialize and free struct nand_bbt.
> >> >
> >> > Below is mtd folder structure we want:
> >> >         mtd
> >> >         ├── Kconfig
> >> >         ├── Makefile
> >> >         ├── ...
> >> >         ├── nand_bbt.c
> >>
> >> Hm.. I'm not sure about having nand_bbt.c in drivers/mtd.
> >> What's wrong with drivers/mtd/nand ?
> >
> > I haven't reviewed the series yet, but I agree. If the BBT code is only
> > meant to be used on NAND based devices, it should probably stay in
> > drivers/mtd/nand.
> >
> >>
> >> In fact, I  was thinking we could go further and clean up the directories a bit
> >> by separating core code, from controllers code, from SPI NAND code:
> >>
> >> drivers/mtd/nand/
> >> drivers/mtd/nand/controllers
> >> drivers/mtd/nand/spi
> >>
> >> Makes any sense?
> >
> > Actually I had the secret plan of moving all (raw) NAND controller
> > drivers into the drivers/mtd/nand/controllers directory, though this
> > was for a different reason: I'd like to create another directory for
> > manufacturer specific code in order to support some advanced features
> > on NANDs that do not implement (or only partially implement) the ONFI
> > standard.
> >
> > The separation you're talking about here is more related to the
> > interface used to communicate with the NAND chip.
> >
> > How about using the following hierarchy?
> >
> > drivers/mtd/nand/<nand-core-code>
> > drivers/mtd/nand/interfaces/raw/<raw-nand-core-code>
> > drivers/mtd/nand/interfaces/raw/controllers/<raw-nand-controller-drivers>
> > drivers/mtd/nand/interfaces/spi/<spi-nand-code>
> > drivers/mtd/nand/interfaces/onenand/<onenand-code>
> > drivers/mtd/nand/chips/<manufacturer-spcific-code>
> >
> > What do you think?
> >
> 
> I believe we are bikeshedding here, but what the heck.
> 
> That seems too involved. A simpler hierarchy could be clear enough,
> and seems to follow what other subsystems do:
> 
> drivers/mtd/nand/<all-nand-core-code>
> drivers/mtd/nand/raw/<raw-nand-controller-drivers>

And probably some common logic in there too.

> drivers/mtd/nand/spi/<spi-nand-code>
> drivers/mtd/nand/onenand/<onenand-code>
> drivers/mtd/nand/chips/<manufacturer-spcific-code>
> 

I'm fine with this one too ;-).

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com