RE: EXTERNAL: Re: [PATCH 1/1] mtd: spi-nor: everspin: add em004lxb entry

[FLAVIO SULIGOI]

Hi Michael,

...
 
> Hi Flavio,
> 
> On Fri Apr 5, 2024 at 12:01 PM CEST, Flavio Suligoi wrote:
> > Add the Everspin EM0004LXB 4Mb (512KB) Industrial STT-MRAM Persistent
> > Memory.
> > This device is JEDEC compatible (JESD251 and JESD251-1), but it is not
> > able to provide SFDP information.
> 
> Did you try the at25 driver if it will fit your usecase? Judging from
> your last response, it sounds like it will do.

Yes, you are right, it works with at25 driver!
Thanks!

At the moment I have to use a page size of 256 bytes, using "atmel,at25".
Since the Everspin EM0004LXB MRAM doesn't have problem with any page size
(theoretically I could use a single page size of 512KB), can I update the
at25.c driver with a support for the EM0004LXB MRAM, as already done for
the Cypress fm25 F-RAM?

> 
> >
> > Link: https://www.everspin.com/file/158244/download
> >
> > Signed-off-by: Flavio Suligoi <f.suligoi@xxxxxxx>
> > ---
> >  drivers/mtd/spi-nor/everspin.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/mtd/spi-nor/everspin.c
> > b/drivers/mtd/spi-nor/everspin.c index 5f321e24ae7d..4741930ce9a8
> > 100644
> > --- a/drivers/mtd/spi-nor/everspin.c
> > +++ b/drivers/mtd/spi-nor/everspin.c
> > @@ -31,6 +31,14 @@ static const struct flash_info everspin_nor_parts[]
> = {
> >  		.size = SZ_512K,
> >  		.sector_size = SZ_512K,
> >  		.flags = SPI_NOR_NO_ERASE | SPI_NOR_NO_FR,
> > +	}, {
> > +		.id = SNOR_ID(0x6b, 0xbb, 0x13),
> > +		.name = "em004lxb",
> > +		.size = SZ_512K,
> > +		.sector_size = SZ_512K,
> > +		.flags = SPI_NOR_NO_ERASE | SPI_NOR_NO_FR | SPI_NOR_HAS_LOCK
> |
> 
> Will it also work without SPI_NOR_NO_ERASE? Also, the flash supports
> fast read, so drop NO_FR. Also, please have a look at [1] for the
> testing requirements.
> 
> Thanks.
> -michael
> 
> > +			 SPI_NOR_HAS_TB | SPI_NOR_4BIT_BP | SPI_NOR_BP3_SR_BIT6,
> > +		.no_sfdp_flags = SPI_NOR_SKIP_SFDP,
> >  	}
> >  };
> >
> 
> [1] https://docs.kernel.org/driver-api/mtd/spi-nor.html

Thanks and best regards,
Flavio