[PATCH v5 1/2] mtd: spinand: Add support for setting plane select bits

[Cheng Ming Lin]

Hi Miquel,

I accidentally sent the previous email before it was finished.

Miquel Raynal <miquel.raynal at bootlin.com> 於 2024年8月30日 週五 下午11:55寫道：
>
> Hi ChengMing,
>
> linchengming884 at gmail.com wrote on Fri, 30 Aug 2024 18:03:09 +0800:
>
> > From: Cheng Ming Lin <chengminglin at mxic.com.tw>
> >
> > Add two flags for inserting the Plane Select bit into the column
> > address during the write_to_cache and the read_from_cache operation.
> >
> > Add the SPINAND_HAS_PP_PLANE_SELECT_BIT flag for serial NAND flash
>
> This flag has been renamed :)

Thank you for the reminder. I will make the necessary changes.

>
> > that require inserting the Plane Select bit into the column address
> > during the write_to_cache operation.
> >
> > Add the SPINAND_HAS_READ_PLANE_SELECT_BIT flag for serial NAND flash
> > that require inserting the Plane Select bit into the column address
> > during the read_from_cache operation.
> >
> > Signed-off-by: Cheng Ming Lin <chengminglin at mxic.com.tw>
> > ---
> >  drivers/mtd/nand/spi/core.c | 6 ++++++
> >  include/linux/mtd/spinand.h | 2 ++
> >  2 files changed, 8 insertions(+)
> >
> > diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> > index e0b6715e5dfe..e7b592cdbb4c 100644
> > --- a/drivers/mtd/nand/spi/core.c
> > +++ b/drivers/mtd/nand/spi/core.c
> > @@ -386,6 +386,9 @@ static int spinand_read_from_cache_op(struct spinand_device *spinand,
> >       else
> >               rdesc = spinand->dirmaps[req->pos.plane].rdesc_ecc;
> >
> > +     if (spinand->flags & SPINAND_HAS_READ_PLANE_SELECT_BIT)
> > +             column |= req->pos.plane << fls(nanddev_page_size(nand));
>
> Isn't there any better way to know what the bit position is?

There are two other methods to determine the bit position:
- column |= res->pos.plane << fls(nand->memorg.pagesize)
- column |= wdesc->info.offset

>
> Thanks,
> Miquèl

Thanks,
Cheng Ming Lin