Re: [PATCH v2 9/9] mtd: rawnand: jz4780-bch: Add support for the JZ4740

[Paul Cercueil]

Le dim. 3 févr. 2019 à 12:07, Boris Brezillon <bbrezillon@xxxxxxxxxx> 
a écrit :
> On Sun, 03 Feb 2019 11:56:32 -0300
> Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
>
> >  Le dim. 3 févr. 2019 à 11:16, Boris Brezillon 
> > <bbrezillon@xxxxxxxxxx>
> >  a écrit :
> >  > On Sun, 03 Feb 2019 10:58:13 -0300
> >  > Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
> >  >
> >  >>  Le dim. 3 févr. 2019 à 4:35, Boris Brezillon
> >  >> <bbrezillon@xxxxxxxxxx>
> >  >>  a écrit :
> >  >>  > On Sat,  2 Feb 2019 20:19:26 -0300
> >  >>  > Paul Cercueil <paul@xxxxxxxxxxxxxxx> wrote:
> >  >>  >
> >  >>  >>  Add the backend code for the jz4780-bch driver to support 
> > the
> >  >> JZ4740
> >  >>  >>  SoC from Ingenic.
> >  >>  >>
> >  >>  >>  Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> >  >>  >>  ---
> >  >>  >>
> >  >>  >>  Changes:
> >  >>  >>
> >  >>  >>  v2: New patch
> >  >>  >>
> >  >>  >>   drivers/mtd/nand/raw/ingenic/Makefile         |   2 +-
> >  >>  >>   drivers/mtd/nand/raw/ingenic/jz4740_bch.c     | 173
> >  >>  >> ++++++++++++++++++
> >  >>  >>   .../mtd/nand/raw/ingenic/jz4780_bch_common.c  |   1 +
> >  >>  >>   .../nand/raw/ingenic/jz4780_bch_internal.h    |   1 +
> >  >>  >>   4 files changed, 176 insertions(+), 1 deletion(-)
> >  >>  >>   create mode 100644 
> > drivers/mtd/nand/raw/ingenic/jz4740_bch.c
> >  >>  >>
> >  >>  >>  diff --git a/drivers/mtd/nand/raw/ingenic/Makefile
> >  >>  >> b/drivers/mtd/nand/raw/ingenic/Makefile
> >  >>  >>  index f38b467490cf..d16c96113a93 100644
> >  >>  >>  --- a/drivers/mtd/nand/raw/ingenic/Makefile
> >  >>  >>  +++ b/drivers/mtd/nand/raw/ingenic/Makefile
> >  >>  >>  @@ -1,3 +1,3 @@
> >  >>  >>   obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
> >  >>  >>   obj-$(CONFIG_MTD_NAND_JZ4780) += jz4780_nand.o
> >  >> jz4780_bch_common.o
> >  >>  >> \
> >  >>  >>  -				 jz4780_bch.o jz4725b_bch.o
> >  >>  >>  +				 jz4780_bch.o jz4725b_bch.o jz4740_bch.o
> >  >>  >
> >  >>  > I still don't see the point of the 
> > jz4780_bch_common/jz47xxx_bch
> >  >>  > separation. You seem to always embed all objects anyway, so 
> > you
> >  >> can
> >  >>  > just put the code for both engines in the same source file and
> >  >> decide
> >  >>  > which one to use based on the compat (which you already do
> >  >> anyway).
> >  >>
> >  >>  Each SoC has a different set of registers for the BCH hardware. 
> > I
> >  >> can
> >  >>  try to
> >  >>  cram everything into one file, but it won't be that much 
> > cleaner.
> >  >
> >  > Then maybe they deserve separate drivers/modules.
> >  >
> >  > BTW, didn't you say that one IP uses Reed-Salomon instead of BCH. 
> > I'd
> >  > suggest prefixing structs and functions with jz47xx_ecc instead of
> >  > jz47xx_bch and naming the common part jz47xx_ecc.c to reflect 
> > that.
> >
> >  Would it be a good idea to make a generic ECC API that the 
> > jz47xx_nand
> >  driver could use? Then the three jz47xx BCH codepaths could be 
> > separate
> >  drivers that register with the generic ECC core.
>
> Definitely. Actually, Miquel is already working on that, but I don't
> think it's a good idea to wait for this new framework to be finished 
> to
> get your changes merged. So I'd recommend having a jz specific ECC API
> (pretty much the one you have in the common file expect it would be
> prefixed with _ecc instead of _bch) and convert it to the generic
> approach afterwards. Given the size of the common.c file, you can even
> put everything in jz47xx_ecc.h as inline funcs to avoid having yet
> another module.

Ok, perfect, I'll do that.
Thank you for your input!