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

From: Paul Cercueil
Date: Sun Feb 03 2019 - 09:57:04 EST




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.