[PATCH 01/10] mtd: set the cell information for ONFI nand

[Gupta, Pekon]

Hi,
> 
> The current code does not set the SLC/MLC information for onfi nand.
> (This makes that the kernel treats all the onfi nand as SLC nand.)
> 
> This patch fills the chip->cellinfo when the onfi nand is a MLC(or TLC) nand
> (p->bits_per_cell > 1).
> 
> The macro NAND_CI_CELLTYPE_SHIFT is added to avoid the hardcode.
> 
> Signed-off-by: Huang Shijie <b32955 at freescale.com>
> ---
>  drivers/mtd/nand/nand_base.c |    3 +++
>  include/linux/mtd/nand.h     |    1 +
>  2 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index ff605c8..ee1aa52 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -2988,6 +2988,9 @@ static int nand_flash_detect_onfi(struct mtd_info
> *mtd, struct nand_chip *chip,
>  	chip->chipsize = le32_to_cpu(p->blocks_per_lun);
>  	chip->chipsize *= (uint64_t)mtd->erasesize * p->lun_count;
> 
> +	/* @bits_per_cell equals 1 means this is a SLC nand. */
> +	chip->cellinfo = (p->bits_per_cell - 1) << NAND_CI_CELLTYPE_SHIFT;
> +
[Pekon]: For future scalability, good to update only MLC related bit-fields
So ORing instead of assigning..
chip->cellinfo |= (p->bits_per_cell - 1) << NAND_CI_CELLTYPE_SHIFT;

>  	if (onfi_feature(chip) & ONFI_FEATURE_16_BIT_BUS)
>  		*busw = NAND_BUSWIDTH_16;
>  	else
> diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> index ac8e89d..bf743ba 100644
> --- a/include/linux/mtd/nand.h
> +++ b/include/linux/mtd/nand.h
> @@ -198,6 +198,7 @@ typedef enum {
>  /* Cell info constants */
>  #define NAND_CI_CHIPNR_MSK	0x03
>  #define NAND_CI_CELLTYPE_MSK	0x0C
> +#define NAND_CI_CELLTYPE_SHIFT	2
> 
>  /* Keep gcc happy */
>  struct nand_chip;
> --
> 1.7.1
> 

With regards, pekon