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

Miquel Raynal miquel.raynal at bootlin.com
Mon Sep 2 05:28:53 PDT 2024


Hi Cheng,

linchengming884 at gmail.com wrote on Mon, 2 Sep 2024 16:42:55 +0800:

> 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

Ok, let's keep it is as-is for now.

Thanks,
Miquèl



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