Re: [RESEND PATCH v2 21/53] mtd: nand: denali: move multi device fixup code to a helper function

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Thu, 23 Mar 2017 05:07:20 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> Collect multi NAND fixups into a helper function instead of
> scattering them in denali_init().
> 
> I am rewording the comment block to clearly explain what is called
> "multi device".

I will take the patch (and the next one too), but I might reconsider
supporting this kind of thing (2 x 8bits devices connected on a 16bits
bus) in the core.

> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
> Changes in v2:
>   - Reword the comment block for clarification
> 
>  drivers/mtd/nand/denali.c | 54 +++++++++++++++++++++++++++++------------------
>  1 file changed, 33 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index 1706975..4e63d57 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -1458,6 +1458,36 @@ static void denali_drv_init(struct denali_nand_info *denali)
>  	denali->irq_status = 0;
>  }
>  
> +static void denali_multidev_fixup(struct denali_nand_info *denali)
> +{
> +	struct nand_chip *chip = &denali->nand;
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +
> +	/*
> +	 * Support for multi device:
> +	 * When the IP configuration is x16 capable and two x8 chips are
> +	 * connected in parallel, DEVICES_CONNECTED should be set to 2.
> +	 * In this case, the core framework knows nothing about this fact,
> +	 * so we should tell it the _logical_ pagesize and anything necessary.
> +	 */
> +	denali->devnum = ioread32(denali->flash_reg + DEVICES_CONNECTED);
> +
> +	mtd->size <<= denali->devnum - 1;
> +	mtd->erasesize <<= denali->devnum - 1;
> +	mtd->writesize <<= denali->devnum - 1;
> +	mtd->oobsize <<= denali->devnum - 1;
> +	chip->chipsize <<= denali->devnum - 1;
> +	chip->page_shift += denali->devnum - 1;
> +	chip->phys_erase_shift += denali->devnum - 1;
> +	chip->bbt_erase_shift += denali->devnum - 1;
> +	chip->chip_shift += denali->devnum - 1;
> +	chip->pagemask <<= denali->devnum - 1;
> +	chip->ecc.size *= denali->devnum;
> +	chip->ecc.bytes *= denali->devnum;
> +	chip->ecc.strength *= denali->devnum;
> +	denali->bbtskipbytes *= denali->devnum;
> +}
> +
>  int denali_init(struct denali_nand_info *denali)
>  {
>  	struct nand_chip *chip = &denali->nand;
> @@ -1540,24 +1570,6 @@ int denali_init(struct denali_nand_info *denali)
>  	}
>  
>  	/*
> -	 * support for multi nand
> -	 * MTD known nothing about multi nand, so we should tell it
> -	 * the real pagesize and anything necessery
> -	 */
> -	denali->devnum = ioread32(denali->flash_reg + DEVICES_CONNECTED);
> -	chip->chipsize <<= denali->devnum - 1;
> -	chip->page_shift += denali->devnum - 1;
> -	chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
> -	chip->bbt_erase_shift += denali->devnum - 1;
> -	chip->phys_erase_shift = chip->bbt_erase_shift;
> -	chip->chip_shift += denali->devnum - 1;
> -	mtd->writesize <<= denali->devnum - 1;
> -	mtd->oobsize <<= denali->devnum - 1;
> -	mtd->erasesize <<= denali->devnum - 1;
> -	mtd->size = chip->numchips * chip->chipsize;
> -	denali->bbtskipbytes *= denali->devnum;
> -
> -	/*
>  	 * second stage of the NAND scan
>  	 * this stage requires information regarding ECC and
>  	 * bad block management.
> @@ -1600,11 +1612,9 @@ int denali_init(struct denali_nand_info *denali)
>  	}
>  
>  	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
> -	chip->ecc.bytes *= denali->devnum;
> -	chip->ecc.strength *= denali->devnum;
>  
>  	/* override the default read operations */
> -	chip->ecc.size = ECC_SECTOR_SIZE * denali->devnum;
> +	chip->ecc.size = ECC_SECTOR_SIZE;
>  	chip->ecc.read_page = denali_read_page;
>  	chip->ecc.read_page_raw = denali_read_page_raw;
>  	chip->ecc.write_page = denali_write_page;
> @@ -1613,6 +1623,8 @@ int denali_init(struct denali_nand_info *denali)
>  	chip->ecc.write_oob = denali_write_oob;
>  	chip->erase = denali_erase;
>  
> +	denali_multidev_fixup(denali);
> +
>  	ret = nand_scan_tail(mtd);
>  	if (ret)
>  		goto failed_req_irq;