linux-kernel - Re: [RFC PATCH] mtd: rawnand: ams-delta: use ->exec

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Message-ID: <20181003143054.597b3a9e@bbrezillon>
Date:   Wed, 3 Oct 2018 14:30:54 +0200
From:   Boris Brezillon <boris.brezillon@...tlin.com>
To:     Janusz Krzysztofik <jmkrzyszt@...il.com>
Cc:     Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Marek Vasut <marek.vasut@...il.com>,
        linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH] mtd: rawnand: ams-delta: use ->exec_op()

Hi Janusz,

On Wed,  3 Oct 2018 14:00:28 +0200
Janusz Krzysztofik <jmkrzyszt@...il.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.

> otherwise that function would probabaly have to be

				^ probably


> 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?

> 
> Suggested-by: Boris Brezillon <boris.brezillon@...tlin.com>
> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@...il.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.

Regards,

Boris