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Date:   Sun, 03 Feb 2019 12:41:30 -0300
From:   Paul Cercueil <paul@crapouillou.net>
Subject: Re: [PATCH v2 9/9] mtd: rawnand: jz4780-bch: Add support for the
 JZ4740
To:     Boris Brezillon <bbrezillon@kernel.org>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Harvey Hunt <harveyhuntnexus@gmail.com>,
        Mathieu Malaterre <malat@debian.org>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
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Le dim. 3 f=E9vr. 2019 =E0 12:07, Boris Brezillon <bbrezillon@kernel.org>=20
a =E9crit :
> On Sun, 03 Feb 2019 11:56:32 -0300
> Paul Cercueil <paul@crapouillou.net> wrote:
>=20
>>  Le dim. 3 f=E9vr. 2019 =E0 11:16, Boris Brezillon=20
>> <bbrezillon@kernel.org>
>>  a =E9crit :
>>  > On Sun, 03 Feb 2019 10:58:13 -0300
>>  > Paul Cercueil <paul@crapouillou.net> wrote:
>>  >
>>  >>  Le dim. 3 f=E9vr. 2019 =E0 4:35, Boris Brezillon
>>  >> <bbrezillon@kernel.org>
>>  >>  a =E9crit :
>>  >>  > On Sat,  2 Feb 2019 20:19:26 -0300
>>  >>  > Paul Cercueil <paul@crapouillou.net> wrote:
>>  >>  >
>>  >>  >>  Add the backend code for the jz4780-bch driver to support=20
>> the
>>  >> JZ4740
>>  >>  >>  SoC from Ingenic.
>>  >>  >>
>>  >>  >>  Signed-off-by: Paul Cercueil <paul@crapouillou.net>
>>  >>  >>  ---
>>  >>  >>
>>  >>  >>  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=20
>> 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-$(CONFIG_MTD_NAND_JZ4740) +=3D jz4740_nand.o
>>  >>  >>   obj-$(CONFIG_MTD_NAND_JZ4780) +=3D 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=20
>> jz4780_bch_common/jz47xxx_bch
>>  >>  > separation. You seem to always embed all objects anyway, so=20
>> 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.=20
>> I
>>  >> can
>>  >>  try to
>>  >>  cram everything into one file, but it won't be that much=20
>> cleaner.
>>  >
>>  > Then maybe they deserve separate drivers/modules.
>>  >
>>  > BTW, didn't you say that one IP uses Reed-Salomon instead of BCH.=20
>> I'd
>>  > suggest prefixing structs and functions with jz47xx_ecc instead of
>>  > jz47xx_bch and naming the common part jz47xx_ecc.c to reflect=20
>> that.
>>=20
>>  Would it be a good idea to make a generic ECC API that the=20
>> jz47xx_nand
>>  driver could use? Then the three jz47xx BCH codepaths could be=20
>> separate
>>  drivers that register with the generic ECC core.
>=20
> 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=20
> 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!
=