[PATCH v2 2/2] spi: npcm-fiu: add NPCM FIU controller driver

Tomer Maimon tmaimon77 at gmail.com
Sat Aug 10 01:47:08 AEST 2019


On Fri, 9 Aug 2019 at 18:26, Boris Brezillon <boris.brezillon at collabora.com>
wrote:

> On Fri, 9 Aug 2019 18:26:23 +0300
> Tomer Maimon <tmaimon77 at gmail.com> wrote:
>
> > Hi Boris,
> >
> > Thanks a lot for your comment.
> >
> > On Thu, 8 Aug 2019 at 18:32, Boris Brezillon <
> boris.brezillon at collabora.com>
> > wrote:
> >
> > > On Thu,  8 Aug 2019 16:14:48 +0300
> > > Tomer Maimon <tmaimon77 at gmail.com> wrote:
> > >
> > >
> > > > +
> > > > +static const struct spi_controller_mem_ops npcm_fiu_mem_ops = {
> > > > +     .exec_op = npcm_fiu_exec_op,
> > >
> > > No npcm_supports_op()? That's suspicious, especially after looking at
> > > the npcm_fiu_exec_op() (and the functions called from there) where the
> > > requested ->buswidth seems to be completely ignored...
> > >
> > > Sorry but I do not fully understand it, do you mean a support for the
> > buswidth?
> > If yes it been done in the UMA functions as follow:
> >
> >                 uma_cfg |= ilog2(op->cmd.buswidth);
> >                 uma_cfg |= ilog2(op->addr.buswidth) <<
> >                         NPCM_FIU_UMA_CFG_ADBPCK_SHIFT;
> >                 uma_cfg |= ilog2(op->data.buswidth) <<
> >                         NPCM_FIU_UMA_CFG_WDBPCK_SHIFT;
> >                 uma_cfg |= op->addr.nbytes <<
> NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT;
> >                 regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR,
> op->addr.val);
> >
>
> Hm, the default supports_op() implementation might be just fine for
> your use case. But there's one thing you still need to check: the
> number of addr cycles (or address size as you call it in this driver).
> Looks like your IP is limited to 4 address cycles, if I'm right, you
> should reject any operation that have op->addr.nbytes > 4. I also
>
Indeed our IP limited to 4 address cycle (bytes) do we have NOR Flash with
more than 32bit address?
I will add this limitation thanks!

> wonder if there's a limitation on the data size you can have on a
> single transfer. If there's one you should implement ->adjust_op() too.
>
there is a limitation in a single transfer but I handle it in the
npcm_fiu_manualwrite
function.
Do you suggest to use ->adjust_op() instead?
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