[U-Boot] [PATCH] mtd: atmel_nand: according to pmecc version to perform 0xff page correction

[Bo Shen <voice.shen@atmel.com>]

Hi Josh,

On 01/16/2015 11:54 AM, Josh Wu wrote:
> As the PMECC hardware has different version. In SAMA5D4 chip, the PMECC ip
> can generate 0xff pmecc ECC value for all 0xff sector.
>
> According to this, add PMECC version check, if it's SAMA5D4 then we always
> let PMECC hardware to correct it.
>
> Signed-off-by: Josh Wu <josh.wu@atmel.com>

except the nitpick.

Acked-by: Bo Shen <voice.shen@atmel.com>

>
> ---
>
>   drivers/mtd/nand/atmel_nand.c     |  9 +++++++++
>   drivers/mtd/nand/atmel_nand_ecc.h | 20 ++++++++++++++++++++
>   2 files changed, 29 insertions(+)
>
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 620b6e8..b16e3aa 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -44,6 +44,7 @@ struct atmel_nand_host {
>   	u8		pmecc_corr_cap;
>   	u16		pmecc_sector_size;
>   	u32		pmecc_index_table_offset;
> +	u32		pmecc_version;
>
>   	int		pmecc_bytes_per_sector;
>   	int		pmecc_sector_number;
> @@ -486,6 +487,10 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
>   	int i, err_nbr, eccbytes;
>   	uint8_t *buf_pos;
>
> +	/* SAMA5D4 PMECC IP can correct errors for all 0xff page */
> +	if (host->pmecc_version >= PMECC_VERSION_SAMA5D4)

I think we can hard coded here, then we can drop the definition in 
header file.

> +		goto normal_check;
> +
>   	eccbytes = nand_chip->ecc.bytes;
>   	for (i = 0; i < eccbytes; i++)
>   		if (ecc[i] != 0xff)
> @@ -961,6 +966,10 @@ static int atmel_pmecc_nand_init_params(struct nand_chip *nand,
>   	nand->ecc.write_page = atmel_nand_pmecc_write_page;
>   	nand->ecc.strength = cap;
>
> +	/* Check the PMECC ip version */
> +	host->pmecc_version = pmecc_readl(host->pmerrloc, version);
> +	dev_dbg(host->dev, "PMECC IP version is: %x\n", host->pmecc_version);
> +
>   	atmel_pmecc_core_init(mtd);
>
>   	return 0;
> diff --git a/drivers/mtd/nand/atmel_nand_ecc.h b/drivers/mtd/nand/atmel_nand_ecc.h
> index eac860d..b2d2682 100644
> --- a/drivers/mtd/nand/atmel_nand_ecc.h
> +++ b/drivers/mtd/nand/atmel_nand_ecc.h
> @@ -123,6 +123,20 @@ struct pmecc_errloc_regs {
>   	u32 sigma[25];	/* 0x28-0x88 Error Location Sigma Registers */
>   	u32 el[24];	/* 0x8C-0xE8 Error Location Registers */
>   	u32 reserved1[5];	/* 0xEC-0xFC Reserved */
> +
> +	/*
> +	 * 0x100-0x1F8:
> +	 *   Reserved for AT91SAM9X5, AT91SAM9N12.
> +	 *   HSMC registers for SAMA5D3, SAMA5D4.
> +	 */

I think no need to add this.

> +	u32 reserved2[63];
> +
> +	/*
> +	 * 0x1FC:
> +	 *   PMECC version for AT91SAM9X5, AT91SAM9N12.
> +	 *   HSMC version for SAMA5D3, SAMA5D4. Can refer as PMECC version.
> +	 */

ditto.

> +	u32 version;
>   };
>
>   /* For Error Location Configuration Register */
> @@ -137,6 +151,12 @@ struct pmecc_errloc_regs {
>   #define		PMERRLOC_ERR_NUM_MASK		(0x1f << 8)
>   #define		PMERRLOC_CALC_DONE		(1 << 0)
>
> +/* PMECC IP version */
> +#define PMECC_VERSION_SAMA5D4			0x113
> +#define PMECC_VERSION_SAMA5D3			0x112
> +#define PMECC_VERSION_AT91SAM9N12		0x102

No where will use the upper three definitions, we can drop them.

> +#define PMECC_VERSION_AT91SAM9X5		0x101

If hard coded, we can drop it also.

> +
>   /* Galois field dimension */
>   #define PMECC_GF_DIMENSION_13			13
>   #define PMECC_GF_DIMENSION_14			14
>

Best Regards,
Bo Shen