[PATCH 2/2] mtd: nand: raw: denali: Wait for reset completion status

[Tan, Ley Foon]

> -----Original Message-----
> From: Masahiro Yamada <masahiroy at kernel.org>
> Sent: Friday, July 10, 2020 12:27 AM
> To: Tan, Ley Foon <ley.foon.tan at intel.com>
> Cc: U-Boot Mailing List <u-boot at lists.denx.de>; Simon Glass
> <sjg at chromium.org>; See, Chin Liang <chin.liang.see at intel.com>; Bacrau,
> Radu <radu.bacrau at intel.com>; Marek Vasut <marex at denx.de>
> Subject: Re: [PATCH 2/2] mtd: nand: raw: denali: Wait for reset completion
> status
> 
> On Mon, Jun 29, 2020 at 7:12 PM Ley Foon Tan <ley.foon.tan at intel.com>
> wrote:
> >
> > Fixed delay 200us is not working in certain platforms. Change to poll
> > for reset completion status to have more reliable reset process.
> >
> > Controller will set the rst_comp bit in intr_status register after
> > controller has completed its reset and initialization process.
> >
> > Signed-off-by: Radu Bacrau <radu.bacrau at intel.com>
> > Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>
> > ---
> >  drivers/mtd/nand/raw/denali.c    | 11 +++++++++++
> >  drivers/mtd/nand/raw/denali.h    |  1 +
> >  drivers/mtd/nand/raw/denali_dt.c | 10 +++++++---
> >  3 files changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/raw/denali.c
> > b/drivers/mtd/nand/raw/denali.c index 15e90291de09..ab91db85467d
> > 100644
> > --- a/drivers/mtd/nand/raw/denali.c
> > +++ b/drivers/mtd/nand/raw/denali.c
> > @@ -1220,6 +1220,17 @@ static int denali_multidev_fixup(struct
> denali_nand_info *denali)
> >         return 0;
> >  }
> >
> > +int denali_wait_reset_complete(struct denali_nand_info *denali) {
> > +       u32 irq_status;
> > +
> > +       irq_status = denali_wait_for_irq(denali, INTR__RST_COMP);
> > +       if (!(irq_status & INTR__RST_COMP))
> > +               return -EIO;
> > +
> > +       return 0;
> > +}
> > +
> >  int denali_init(struct denali_nand_info *denali)  {
> >         struct nand_chip *chip = &denali->nand; diff --git
> > a/drivers/mtd/nand/raw/denali.h b/drivers/mtd/nand/raw/denali.h index
> > 019deda094e5..6cd02b2e26ee 100644
> > --- a/drivers/mtd/nand/raw/denali.h
> > +++ b/drivers/mtd/nand/raw/denali.h
> > @@ -321,6 +321,7 @@ struct denali_nand_info {
> >  #define DENALI_CAP_DMA_64BIT                   BIT(1)
> >
> >  int denali_calc_ecc_bytes(int step_size, int strength);
> > +int denali_wait_reset_complete(struct denali_nand_info *denali);
> >  int denali_init(struct denali_nand_info *denali);
> >
> >  #endif /* __DENALI_H__ */
> > diff --git a/drivers/mtd/nand/raw/denali_dt.c
> > b/drivers/mtd/nand/raw/denali_dt.c
> > index 75ad15b0758c..8a6950f8a39f 100644
> > --- a/drivers/mtd/nand/raw/denali_dt.c
> > +++ b/drivers/mtd/nand/raw/denali_dt.c
> > @@ -154,10 +154,14 @@ static int denali_dt_probe(struct udevice *dev)
> >
> >                 /*
> >                  * When the reset is deasserted, the initialization sequence is
> > -                * kicked (bootstrap process). The driver must wait until it is
> > -                * finished. Otherwise, it will result in unpredictable behavior.
> > +                * kicked. The driver must wait until it is finished. Otherwise,
> > +                * it will result in unpredictable behavior.
> 
> 
> What is your motivation for this hunk of change?
> (removal of "bootstrap process")
> 
> What was wrong with the current comment block?
> 
> The term "bootstrap" appears in the
> Cadence (Denali) Flash Controller User Guide.
> 
No special reason. Will send v2 patch to revert back "bootstrap process" in comment.

Thanks.

Regards
Ley Foon