[38/39] mtd: nand: denali: remove Toshiba, Hynix specific fixup code

The Denali IP can automatically detect device parameters such as
page size, device width, etc. and this driver currently relies on it.
However, this hardware function is problematic.

[1] Due to a hardware bug, various misdetected cases are known.
    That is why get_toshiba_nand_para(), get_hynix_nand_para() exist
    to fix the misdetected parameters.  It is not realistic to add a
    new NAND device to the *black list* every time we are hit by a
    misdetected case.  We would never be able to guarantee that all
    the cases are covered.

[2] Because this feature is unreliable, it is disabled on some
    platforms.

The nand_scan_ident() sets device parameters such as mtd->writesize,
mtd->erasesize, etc. in a more tested way.  We should not set the
hardware registers in a different, unreliable way.  Instead, set
the parameters from nand_scan_ident() back to the registers.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/mtd/nand/denali.c | 39 ++++++---------------------------------
 1 file changed, 6 insertions(+), 33 deletions(-)

On Sun, 27 Nov 2016 03:06:24 +0900
Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> The Denali IP can automatically detect device parameters such as
> page size, device width, etc. and this driver currently relies on it.
> However, this hardware function is problematic.
> 
> [1] Due to a hardware bug, various misdetected cases are known.
>     That is why get_toshiba_nand_para(), get_hynix_nand_para() exist
>     to fix the misdetected parameters.  It is not realistic to add a
>     new NAND device to the *black list* every time we are hit by a
>     misdetected case.  We would never be able to guarantee that all
>     the cases are covered.
> 
> [2] Because this feature is unreliable, it is disabled on some
>     platforms.
> 
> The nand_scan_ident() sets device parameters such as mtd->writesize,
> mtd->erasesize, etc. in a more tested way.  We should not set the
> hardware registers in a different, unreliable way.  Instead, set
> the parameters from nand_scan_ident() back to the registers.
> 

Thanks a lot for fixing that.

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> ---
> 
>  drivers/mtd/nand/denali.c | 39 ++++++---------------------------------
>  1 file changed, 6 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index df174ca..1aa19ec 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -338,35 +338,6 @@ static void get_samsung_nand_para(struct denali_nand_info *denali, u8 device_id)
>  	}
>  }
>  
> -static void get_toshiba_nand_para(struct denali_nand_info *denali)
> -{
> -	/*
> -	 * Workaround to fix a controller bug which reports a wrong
> -	 * spare area size for some kind of Toshiba NAND device
> -	 */
> -	if ((ioread32(denali->flash_reg + DEVICE_MAIN_AREA_SIZE) == 4096) &&
> -		(ioread32(denali->flash_reg + DEVICE_SPARE_AREA_SIZE) == 64))
> -		iowrite32(216, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
> -}
> -
> -static void get_hynix_nand_para(struct denali_nand_info *denali, u8 device_id)
> -{
> -	switch (device_id) {
> -	case 0xD5: /* Hynix H27UAG8T2A, H27UBG8U5A or H27UCG8VFA */
> -	case 0xD7: /* Hynix H27UDG8VEM, H27UCG8UDM or H27UCG8V5A */
> -		iowrite32(128, denali->flash_reg + PAGES_PER_BLOCK);
> -		iowrite32(4096, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
> -		iowrite32(224, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
> -		iowrite32(0, denali->flash_reg + DEVICE_WIDTH);
> -		break;
> -	default:
> -		dev_warn(denali->dev,
> -			 "Unknown Hynix NAND (Device ID: 0x%x).\n"
> -			 "Will use default parameter values instead.\n",
> -			 device_id);
> -	}
> -}
> -
>  /*
>   * determines how many NAND chips are connected to the controller. Note for
>   * Intel CE4100 devices we don't support more than one device.
> @@ -468,10 +439,6 @@ static u16 denali_nand_timing_set(struct denali_nand_info *denali)
>  			return FAIL;
>  	} else if (maf_id == 0xEC) { /* Samsung NAND */
>  		get_samsung_nand_para(denali, device_id);
> -	} else if (maf_id == 0x98) { /* Toshiba NAND */
> -		get_toshiba_nand_para(denali);
> -	} else if (maf_id == 0xAD) { /* Hynix NAND */
> -		get_hynix_nand_para(denali, device_id);
>  	}
>  
>  	dev_info(denali->dev,
> @@ -1661,6 +1628,12 @@ int denali_init(struct denali_nand_info *denali)
>  						chip->ecc.strength);
>  
>  	iowrite32(chip->ecc.strength, denali->flash_reg + ECC_CORRECTION);
> +	iowrite32(mtd->erasesize / mtd->writesize,
> +		  denali->flash_reg + PAGES_PER_BLOCK);
> +	iowrite32(denali->nand.options & NAND_BUSWIDTH_16 ? 1 : 0,
> +		  denali->flash_reg + DEVICE_WIDTH);
> +	iowrite32(mtd->writesize, denali->flash_reg + DEVICE_MAIN_AREA_SIZE);
> +	iowrite32(mtd->oobsize, denali->flash_reg + DEVICE_SPARE_AREA_SIZE);
>  
>  	mtd_set_ooblayout(mtd, &denali_ooblayout_ops);
>