RE: [EXT] Re: [PATCH 6/8] mtd: spinand: micron: Turn driver implementation generic

["Shivamurthy Shastri (sshivamurthy)" <sshivamurthy@xxxxxxxxxx>]

Hi Miquel,

> 
> Hi Shiva,
> 
> shiva.linuxworks@xxxxxxxxx wrote on Mon, 22 Jul 2019 07:56:19 +0200:
> 
> > From: Shivamurthy Shastri <sshivamurthy@xxxxxxxxxx>
> >
> 
> I am not sure the "turn implemenatation generic" title describes what
> you do.
> 
> > Driver is redesigned using parameter page to support Micron SPI NAND
> > flashes.
> 
> Redesigned is perhaps a bit too much.
> 
> "
> > The reason why spinand_select_op_variant globalized is that the Micron
> > driver no longer calling spinand_match_and_init.
> >
> > Signed-off-by: Shivamurthy Shastri <sshivamurthy@xxxxxxxxxx>
> > ---
> >  drivers/mtd/nand/spi/core.c   |  2 +-
> >  drivers/mtd/nand/spi/micron.c | 61 +++++++++++++++++++++++++-------
> ---
> >  include/linux/mtd/spinand.h   |  4 +++
> >  3 files changed, 49 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> > index 7ae76dab9141..aae715d388b7 100644
> > --- a/drivers/mtd/nand/spi/core.c
> > +++ b/drivers/mtd/nand/spi/core.c
> > @@ -920,7 +920,7 @@ static void spinand_manufacturer_cleanup(struct
> spinand_device *spinand)
> >  		return spinand->manufacturer->ops->cleanup(spinand);
> >  }
> >
> > -static const struct spi_mem_op *
> > +const struct spi_mem_op *
> >  spinand_select_op_variant(struct spinand_device *spinand,
> >  			  const struct spinand_op_variants *variants)
> >  {
> > diff --git a/drivers/mtd/nand/spi/micron.c
> b/drivers/mtd/nand/spi/micron.c
> > index 95bc5264ebc1..6fde93ec23a1 100644
> > --- a/drivers/mtd/nand/spi/micron.c
> > +++ b/drivers/mtd/nand/spi/micron.c
> > @@ -90,22 +90,10 @@ static int micron_ecc_get_status(struct
> spinand_device *spinand,
> >  	return -EINVAL;
> >  }
> >
> > -static const struct spinand_info micron_spinand_table[] = {
> > -	SPINAND_INFO("MT29F2G01ABAGD", 0x24,
> > -		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 2, 1, 1),
> > -		     NAND_ECCREQ(8, 512),
> > -		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
> > -					      &write_cache_variants,
> > -					      &update_cache_variants),
> > -		     0,
> > -		     SPINAND_ECCINFO(&micron_ooblayout_ops,
> > -				     micron_ecc_get_status)),
> > -};
> > -
> 
> I don't know if it is wise to drop this structure.
> 
> >  static int micron_spinand_detect(struct spinand_device *spinand)
> >  {
> > +	const struct spi_mem_op *op;
> >  	u8 *id = spinand->id.data;
> > -	int ret;
> >
> >  	/*
> >  	 * Micron SPI NAND read ID need a dummy byte,
> > @@ -114,16 +102,55 @@ static int micron_spinand_detect(struct
> spinand_device *spinand)
> >  	if (id[1] != SPINAND_MFR_MICRON)
> >  		return 0;
> >
> > -	ret = spinand_match_and_init(spinand, micron_spinand_table,
> > -				     ARRAY_SIZE(micron_spinand_table),
> id[2]);
> 
> I am not sure this is the right solution. I would keep this call and
> overwrite what you need to overwrite with the fixup hook.
> 

Then, I will have dummy structure like below.

static const struct spinand_info micron_spinand_table[] = {                      
        SPINAND_INFO(NULL, 0,                                                                    
                     NAND_MEMORG(0, 0, 0, 0, 0, 0, 0, 0, 0),           
                     NAND_ECCREQ(0, 0),                                                                       
                     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,              
                                              &write_cache_variants,             
                                              &update_cache_variants),           
                     0,                                                                                         
                     SPINAND_ECCINFO(&micron_ooblayout_ops,                      
                                     micron_ecc_get_status)),                    
};                                    

Let me know if you are thinking for different approach.

> > -	if (ret)
> > -		return ret;
> > +	spinand->flags = 0;
> > +	spinand->eccinfo.get_status = micron_ecc_get_status;
> > +	spinand->eccinfo.ooblayout = &micron_ooblayout_ops;
> > +
> > +	op = spinand_select_op_variant(spinand,
> > +				       &read_cache_variants);
> > +	if (!op)
> > +		return -ENOTSUPP;
> > +
> > +	spinand->op_templates.read_cache = op;
> > +
> > +	op = spinand_select_op_variant(spinand,
> > +				       &write_cache_variants);
> > +	if (!op)
> > +		return -ENOTSUPP;
> > +
> > +	spinand->op_templates.write_cache = op;
> > +
> > +	op = spinand_select_op_variant(spinand,
> > +				       &update_cache_variants);
> > +	spinand->op_templates.update_cache = op;
> >
> >  	return 1;
> >  }
> >
> > +static void micron_fixup_param_page(struct spinand_device *spinand,
> > +				    struct nand_onfi_params *p)
> > +{
> > +	/*
> > +	 * As per Micron datasheets vendor[83] is defined as
> > +	 * die_select_feature
> > +	 */
> > +	if (p->vendor[83] && !p->interleaved_bits)
> > +		spinand->base.memorg.planes_per_lun = 1 << p-
> >vendor[0];
> > +
> > +	spinand->base.memorg.ntargets = p->lun_count;
> > +	spinand->base.memorg.luns_per_target = 1;
> > +
> > +	/*
> > +	 * As per Micron datasheets,
> > +	 * vendor[82] is ECC maximum correctability
> > +	 */
> > +	spinand->base.eccreq.strength = p->vendor[82];
> > +	spinand->base.eccreq.step_size = 512;
> > +}
> > +
> >  static const struct spinand_manufacturer_ops
> micron_spinand_manuf_ops = {
> >  	.detect = micron_spinand_detect,
> > +	.fixup_param_page = micron_fixup_param_page,
> >  };
> >
> >  const struct spinand_manufacturer micron_spinand_manufacturer = {
> > diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
> > index fea820a20bc9..ddb2194273a8 100644
> > --- a/include/linux/mtd/spinand.h
> > +++ b/include/linux/mtd/spinand.h
> > @@ -461,4 +461,8 @@ int spinand_match_and_init(struct spinand_device
> *dev,
> >  int spinand_upd_cfg(struct spinand_device *spinand, u8 mask, u8 val);
> >  int spinand_select_target(struct spinand_device *spinand, unsigned int
> target);
> >
> > +const struct spi_mem_op *
> > +spinand_select_op_variant(struct spinand_device *spinand,
> > +			  const struct spinand_op_variants *variants);
> > +
> >  #endif /* __LINUX_MTD_SPINAND_H */
> 
> 
> 
> 
> Thanks,
> Miquèl
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