[PATCH] mtd: nand: denali: max_banks calculation changed in revision 5.1

[Graham Moore]

Howdy folks,

Any comment on this patch?  Is anyone else using Denali NAND rev 5.1 
controller?

Thanks,
Graham

On 07/21/2015 09:39 AM, Graham Moore wrote:
> Read Denali hardware revision number and use it to
> calculate max_banks,  The encoding of max_banks changed
> in Denali revision 5.1.
>
> Signed-off-by: Graham Moore <grmoore at opensource.altera.com>
> ---
>   drivers/mtd/nand/denali.c |   11 ++++++++++-
>   drivers/mtd/nand/denali.h |    2 ++
>   2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index 870c7fc..a98b41e 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -458,8 +458,17 @@ static void find_valid_banks(struct denali_nand_info *denali)
>   static void detect_max_banks(struct denali_nand_info *denali)
>   {
>   	uint32_t features = ioread32(denali->flash_reg + FEATURES);
> +	/*
> +	 * Read the revision register, so we can calculate the max_banks
> +	 * properly: the encoding changed from rev 5.0 to 5.1
> +	 */
> +	u32 revision = MAKE_COMPARABLE_REVISION(
> +				ioread32(denali->flash_reg + REVISION));
>
> -	denali->max_banks = 2 << (features & FEATURES__N_BANKS);
> +	if (revision < REVISION_5_1)
> +		denali->max_banks = 2 << (features & FEATURES__N_BANKS);
> +	else
> +		denali->max_banks = 1 << (features & FEATURES__N_BANKS);
>   }
>
>   static void detect_partition_feature(struct denali_nand_info *denali)
> diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
> index 145bf88..4bf13bb 100644
> --- a/drivers/mtd/nand/denali.h
> +++ b/drivers/mtd/nand/denali.h
> @@ -178,6 +178,8 @@
>
>   #define REVISION				0x370
>   #define     REVISION__VALUE				0xffff
> +#define MAKE_COMPARABLE_REVISION(x)		swab16(x & REVISION__VALUE)
> +#define REVISION_5_1				0x00000501
>
>   #define ONFI_DEVICE_FEATURES			0x380
>   #define     ONFI_DEVICE_FEATURES__VALUE			0x003f
>