[PATCH] m25p80: Use a 512 byte page size for Spansion flash s25fl512s

[Marek Vasut]

On 01/24/2017 02:52 PM, mark.marshall at omicronenergy.com wrote:
> From: Mark Marshall <mark.marshall at omicronenergy.com>
> 
> The s25fl512s flash from Spansion has a 512 byte write page size,
> which means that we can write 512 bytes at a time (instead of 256).
> 
> This single change makes writing to the flash about 2x faster.
> 
> Signed-off-by: Mark Marshall <mark.marshall at omicronenergy.com>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index da7cd69..c9ac0bf 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -775,6 +775,21 @@ static int spi_nor_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
>  		.page_size = 256,					\
>  		.flags = (_flags),
>  
> +/* Used to set a custom (non 256) page_size */
> +#define INFOP(_jedec_id, _ext_id, _sector_size, _n_sectors, _pg_sz, _flags) \
> +		.id = {							\
> +			((_jedec_id) >> 16) & 0xff,			\
> +			((_jedec_id) >> 8) & 0xff,			\
> +			(_jedec_id) & 0xff,				\
> +			((_ext_id) >> 8) & 0xff,			\
> +			(_ext_id) & 0xff,				\
> +			},						\
> +		.id_len = (!(_jedec_id) ? 0 : (3 + ((_ext_id) ? 2 : 0))), \
> +		.sector_size = (_sector_size),				\
> +		.n_sectors = (_n_sectors),				\
> +		.page_size = (_pg_sz),					\
> +		.flags = (_flags),					\
> +

Maybe it's time to introduce INFO_FULL() instead, where you could
specify the page size and ID length. Adding more and more custom INFOx()
doesn't scale. The INFOx() could then be easily converted
over to INFO_FULL().

One minor bit which could be slightly problematic is the .id_len
field, which is precomputed now, but maybe there is a way to handle
that too.

Thoughts ?

>  #define CAT25_INFO(_sector_size, _n_sectors, _page_size, _addr_width, _flags)	\
>  		.sector_size = (_sector_size),				\
>  		.n_sectors = (_n_sectors),				\
> @@ -905,7 +920,7 @@ static const struct flash_info spi_nor_ids[] = {
>  	{ "s25sl064p",  INFO(0x010216, 0x4d00,  64 * 1024, 128, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
>  	{ "s25fl256s0", INFO(0x010219, 0x4d00, 256 * 1024, 128, 0) },
>  	{ "s25fl256s1", INFO(0x010219, 0x4d01,  64 * 1024, 512, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> -	{ "s25fl512s",  INFO(0x010220, 0x4d00, 256 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> +	{ "s25fl512s",  INFOP(0x010220, 0x4d00, 256 * 1024, 256, 512, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
>  	{ "s70fl01gs",  INFO(0x010221, 0x4d00, 256 * 1024, 256, 0) },
>  	{ "s25sl12800", INFO(0x012018, 0x0300, 256 * 1024,  64, 0) },
>  	{ "s25sl12801", INFO(0x012018, 0x0301,  64 * 1024, 256, 0) },
> 


-- 
Best regards,
Marek Vasut