Re: [PATCH] mtd: spinand: micron: add support for MT29F1G01AAADD

[Marco Felsch <m.felsch@pengutronix.de>]

Hi Miquel,

On 19-08-19 16:34, Miquel Raynal wrote:
> Hi Marco,
> 
> Marco Felsch <m.felsch@pengutronix.de> wrote on Mon, 19 Aug 2019
> 15:30:42 +0200:
> 
> > Hi Miquel,
> > 
> > On 19-08-19 10:17, Miquel Raynal wrote:
> > > Hi Marco,
> > > 
> > > Marco Felsch <m.felsch@pengutronix.de> wrote on Wed, 14 Aug 2019
> > > 10:22:32 +0200:
> > >   
> > > > The MT29F1G01AAADD is a single die, SLC based SPI NAND. It has a
> > > > capacity of 1Gb and supports 4-bit ECC. The datasheet can be found [1].
> > > > 
> > > > Unfortunatly the linked device is marked as EoL, but I will expect that
> > > > the MT29F1G01AAADDH4-ITX behaves the same way.
> > > > 
> > > > [1] https://datasheet.octopart.com/ \
> > > >       MT29F1G01AAADDH4-IT:D-Micron-datasheet-11572380.pdf
> > > > 
> > > > Cc: Peter Pan <peterpandong@micron.com>
> > > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > > ---
> > > >  drivers/mtd/nand/spi/micron.c | 68 +++++++++++++++++++++++++++++++++++
> > > >  1 file changed, 68 insertions(+)
> > > > 
> > > > diff --git a/drivers/mtd/nand/spi/micron.c b/drivers/mtd/nand/spi/micron.c
> > > > index 7d7b1f7fcf71..9d63450afc69 100644
> > > > --- a/drivers/mtd/nand/spi/micron.c
> > > > +++ b/drivers/mtd/nand/spi/micron.c
> > > > @@ -34,6 +34,18 @@ static SPINAND_OP_VARIANTS(update_cache_variants,
> > > >  		SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
> > > >  		SPINAND_PROG_LOAD(false, 0, NULL, 0));
> > > >  
> > > > +static SPINAND_OP_VARIANTS(read_cache_variants_mt29f1g01aaadd,
> > > > +		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
> > > > +		SPINAND_PAGE_READ_FROM_CACHE_X2_OP(0, 1, NULL, 0),
> > > > +		SPINAND_PAGE_READ_FROM_CACHE_OP(true, 0, 1, NULL, 0),
> > > > +		SPINAND_PAGE_READ_FROM_CACHE_OP(false, 0, 1, NULL, 0));
> > > > +
> > > > +static SPINAND_OP_VARIANTS(write_cache_variants_mt29f1g01aaadd,
> > > > +		SPINAND_PROG_LOAD(true, 0, NULL, 0));
> > > > +
> > > > +static SPINAND_OP_VARIANTS(update_cache_variants_mt29f1g01aaadd,
> > > > +		SPINAND_PROG_LOAD(false, 0, NULL, 0));
> > > > +
> > > >  static int mt29f2g01abagd_ooblayout_ecc(struct mtd_info *mtd, int section,
> > > >  					struct mtd_oob_region *region)
> > > >  {
> > > > @@ -90,6 +102,52 @@ static int mt29f2g01abagd_ecc_get_status(struct spinand_device *spinand,
> > > >  	return -EINVAL;
> > > >  }
> > > >  
> > > > +static int mt29f1g01aaadd_ooblayout_ecc(struct mtd_info *mtd, int section,
> > > > +					struct mtd_oob_region *region)
> > > > +{
> > > > +	if (section > 3)
> > > > +		return -ERANGE;
> > > > +
> > > > +	region->offset = (section * 0x10) + 8;  
> > > 
> > > Any reason to use hex here?         ^
> > > 
> > > If not I would prefer decimal numbers.  
> > 
> > Since the datasheet describe it in hex to.
> > 
> > Can you have a look on [1] table 11? May we do something like:
> > 
> > 	region->offset = (section * 0x10) + 0x8;
> > 
> > [1] https://datasheet.octopart.com/MT29F1G01AAADDH4-IT:D-Micron-datasheet-11572380.pdf
> > 
> > > 
> > > Otherwise looks fine.  
> > 
> > Anyway I can change the above code to use only decimal values if you
> > like it more.
> 
> I think it is better to reserve hexadecimal values to register
> operations. Please translate into decimal.

Okay. Just one last question. What is the common way to go to specify
the free area? By this I mean that the NAND has two areas to store the
user metadata calling it 'user metadata I' and 'user metadata II'. 'user
metadata II' isn't ecc protected so I skip them. But the current
supported chip does not skip the user metadata area which isn't
protected [1] table 10.

[1] https://www.micron.com/~/media/documents/products/data-sheet/nand-flash/70-series/m79a_2gb_3v_nand_spi.pdf

Regards,
  Marco

> 
> Thanks,
> Miquèl
> 
> 

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