Re: [PATCH] mtd: spi-nor: Add support for is25lp01g

[ClÃment Leger]

Hi Tudor,

----- On 21 Apr, 2020, at 06:40, Tudor Ambarus Tudor.Ambarus@xxxxxxxxxxxxx wrote:

> On Monday, April 20, 2020 5:50:02 PM EEST ClÃment Leger wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
>> content is safe
>> 
>> Hi Tudor,
> 
> Hi, Clement,
> 
>> 
>> ----- On 20 Apr, 2020, at 14:14, Tudor Ambarus Tudor.Ambarus@xxxxxxxxxxxxx
> wrote:
>> > Hi, Clement,
>> > 
>> > On Friday, April 17, 2020 7:08:39 PM EEST Clement Leger wrote:
>> >> EXTERNAL EMAIL: Do not click links or open attachments unless you know
>> >> the
>> >> content is safe
>> >> 
>> >> Update the issi_parts table for is25lp01g (128MB) device from ISSI.
>> >> Tested on Kalray K200 board.
>> >> 
>> >> Signed-off-by: Clement Leger <cleger@xxxxxxxxx>
>> >> ---
>> >> 
>> >>  drivers/mtd/spi-nor/issi.c | 2 ++
>> >>  1 file changed, 2 insertions(+)
>> >> 
>> >> diff --git a/drivers/mtd/spi-nor/issi.c b/drivers/mtd/spi-nor/issi.c
>> >> index ffcb60e54a80..c3c3438e3d08 100644
>> >> --- a/drivers/mtd/spi-nor/issi.c
>> >> +++ b/drivers/mtd/spi-nor/issi.c
>> >> @@ -49,6 +49,8 @@ static const struct flash_info issi_parts[] = {
>> >> 
>> >>                              SECT_4K | SPI_NOR_DUAL_READ |
>> >>                              SPI_NOR_QUAD_READ
>> >> | 
>> >> | SPI_NOR_4B_OPCODES)
>> >> | 
>> >>                 .fixups = &is25lp256_fixups },
>> >> 
>> >> +       { "is25lp01g",  INFO(0x9d601b, 0, 64 * 1024, 2048,
>> > 
>> > There is a "K" flavor of this flash which has 512 Byte Page size with 256
>> > KB Block size. While the page size can be determined by parsing SFDP, I
>> > think we will have some problems with sector_size because as of now, the
>> > sector_size is always set to 64KB. An incorrect sector_size will affect
>> > erases and locking.
>> Thanks, I did not noticed that ! If I understand, this will require to
>> modify the core to handle sector size the same way as page_size and
>> probably add a fixup to detect the "K" options from SFDP ?
> 
> Right. You can add a post_bfpt fixup hook for this flash. You can
> differentiate between the "K" version and the rest by the page size. Since the
> page size is tightly coupled with the sector size, you can amend both in the
> post_bfpt hook.

Ok, this seems clear ! I'll give it a try. By looking quickly at the code I
think that n_sectors will also have to be updated after discovering the
sector_size from BFPT (for flash size computation). Since some parameters
of the nor are initialized early in spi_nor_info_init_params using
sector_size, should I move the call making use of sector_size later in the
init (in spi_nor_late_init_params for instance) ?

> 
>> This is probably more changes than I can handle, and you can probably drop
>> this patch since not really functional for "K" type flash.
> 
> I dropped it. You should try to fix it, I can guide you if needed. Or I can do
> it myself, but I'll need some help from you at testing.

I will try to do it but I will probably only be able to test the patches in a 
couple of weeks due to our architecture not being rebased on 5.7 yet.

Thanks,

ClÃment

> 
> Cheers,
> ta