Re: [RFC PATCH] mtd: rawnand: ams-delta: use ->exec_op()

Janusz Krzysztofik
2018-10-03T13:54:06Z

On Wednesday, October 3, 2018 2:30:54 PM CEST Boris Brezillon wrote:
> Hi Janusz,
>
> On Wed, 3 Oct 2018 14:00:28 +0200
> Janusz Krzysztofik <jmkrzyszt@gmail.com> wrote:
>
> > Replace legacy callbacks with ->select_chip() and ->exec_op().
>
> Thanks for working on that, that's really appreciated.
>
> >
> > Implementation of NAND_OP_WAITRDY_INSTR has been based on legacy
> > nand_wait_ready(),
>
> I don't remember what the ams-delta ->dev_ready()/->waitfunc() hooks
> are doing, but is shouldn't be too hard to replace them by an
> ams_delta_wait_ready() func.

Default nand_wait() is used as ->waitfunc(), and ->dev_ready() returns R/B
GPIO pin status.

> > otherwise that function would probabaly have to be
>
> ^ probably

Do you think other drivers which now provide ->dev_ready() won't require
reimplementation of nand_wait_ready()?

> > reimplemented inside the driver. Hence, legacy callback ->dev_ready()
> > is still used.
> >
> > Use of IO_ADDR_R and IO_ADDR_W legacy structure members will be dropped
> > later, as soon as the driver is converted to use GPIO API for data I/O.
>
> In the meantime, can you move the iomem pointer to the ams_delta
> private struct so that this driver no longer uses the ->IO_ADDR_R/W
> fields?

OK

> >
> > Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
> > Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
> > ---
> > Hi,
> >
> > I've not tested the change on hardware yet as I'm not sure if:
> > - handling of NCE limited to that inside ->select_chip() is
> > sufficient,
>
> I think it is.
>
> > - releasing ALE / CLE immediately after ams_delta_write_buf() is
> > correct.
>
> Well, you should probably consider waiting for instr->ctx.delay_ns
> nanoseconds after each instruction, but, if it was working before the
> conversion to ->exec_op(), it should work just fine now.

OK, I'll give it a try.

Thanks,
Janusz