Re: [PATCH 24/24] mtd: spinand: winbond: Add support for DTR operations

[Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>]

On 10/25/24 5:15 PM, Miquel Raynal wrote:
> W25N01JW and W25N02JW support many DTR read modes in single, dual and
> quad configurations.
> 
> DTR modes however cannot be used at 166MHz, as the bus frequency in
> this case must be lowered to 80MHz.

ha, what's the benefit then? Aren't we better of with non dtr modes
then? 80 MHz * 2 < 166 MHz?

> 
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
>  drivers/mtd/nand/spi/winbond.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/mtd/nand/spi/winbond.c b/drivers/mtd/nand/spi/winbond.c
> index 9e2562805d23..77897a52b149 100644
> --- a/drivers/mtd/nand/spi/winbond.c
> +++ b/drivers/mtd/nand/spi/winbond.c
> @@ -24,10 +24,15 @@
>   */
>  
>  static SPINAND_OP_VARIANTS(read_cache_dtr_variants,
> +		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_DTR_OP(0, 8, NULL, 0, 80 * HZ_PER_MHZ),
> +		SPINAND_PAGE_READ_FROM_CACHE_X4_DTR_OP(0, 2, NULL, 0, 80 * HZ_PER_MHZ),
>  		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 2, NULL, 0),
>  		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
> +		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_DTR_OP(0, 4, NULL, 0, 80 * HZ_PER_MHZ),
> +		SPINAND_PAGE_READ_FROM_CACHE_X2_DTR_OP(0, 2, NULL, 0, 80 * HZ_PER_MHZ),
>  		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_OP(0, 1, NULL, 0),
>  		SPINAND_PAGE_READ_FROM_CACHE_X2_OP(0, 1, NULL, 0),
> +		SPINAND_PAGE_READ_FROM_CACHE_DTR_OP(0, 2, NULL, 0, 80 * HZ_PER_MHZ),
>  		SPINAND_PAGE_READ_FROM_CACHE_FAST_OP(0, 1, NULL, 0),
>  		SPINAND_PAGE_READ_FROM_CACHE_OP(0, 1, NULL, 0, 54 * HZ_PER_MHZ));
>