From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Pratyush Yadav <p.yadav@ti.com>
Cc: "Nishanth Menon" <nm@ti.com>, "Tero Kristo" <kristo@kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Tudor Ambarus" <tudor.ambarus@microchip.com>,
"Michael Walle" <michael@walle.cc>,
"Richard Weinberger" <richard@nod.at>,
"Vignesh Raghavendra" <vigneshr@ti.com>,
"Mark Brown" <broonie@kernel.org>,
"Cédric Le Goater" <clg@kaod.org>,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
linux-spi@vger.kernel.org
Subject: Re: [RFC PATCH 3/6] mtd: spi-nor: core: run calibration when initialization is done
Date: Wed, 18 May 2022 09:19:31 +0200 [thread overview]
Message-ID: <20220518091931.279c5398@xps-13> (raw)
In-Reply-To: <20220518060640.os5fp5rez4ie7qc4@ti.com>
Hi Pratyush,
p.yadav@ti.com wrote on Wed, 18 May 2022 11:37:05 +0530:
> +Cedric
>
> On 17/05/22 04:02PM, Miquel Raynal wrote:
> > Hi Pratyush,
> >
> > p.yadav@ti.com wrote on Fri, 12 Mar 2021 00:42:13 +0530:
> >
> > > Once the flash is initialized tell the controller it can run
> > > calibration procedures if needed. This can be useful when calibration is
> > > needed to run at higher clock speeds.
> > >
> > > Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
> > > ---
> > > drivers/mtd/spi-nor/core.c | 12 ++++++++++--
> > > 1 file changed, 10 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> > > index 88888df009f0..e0cbcaf1be89 100644
> > > --- a/drivers/mtd/spi-nor/core.c
> > > +++ b/drivers/mtd/spi-nor/core.c
> > > @@ -3650,6 +3650,7 @@ static int spi_nor_probe(struct spi_mem *spimem)
> > > * checking what's really supported using spi_mem_supports_op().
> > > */
> > > const struct spi_nor_hwcaps hwcaps = { .mask = SNOR_HWCAPS_ALL };
> > > + struct spi_mem_op op;
> > > char *flash_name;
> > > int ret;
> > >
> > > @@ -3709,8 +3710,15 @@ static int spi_nor_probe(struct spi_mem *spimem)
> > > if (ret)
> > > return ret;
> > >
> > > - return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
> > > - data ? data->nr_parts : 0);
> > > + ret = mtd_device_register(&nor->mtd, data ? data->parts : NULL,
> > > + data ? data->nr_parts : 0);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + op = spi_nor_spimem_get_read_op(nor);
> >
> > Isn't this too specific? I really don't know much about spi-nors, but I
> > find odd to have this op being created here, why not moving this into
> > the _do_calibration() helper?
>
> Maybe the naming confused you but this is a function in the SPI NOR
> core, not in SPI MEM. SPI NOR supports both SPI MEM based controllers
> and "legacy" controllers, so the convention is to add the "spimem"
> prefix before SPI MEM specific functions. So I don't get the comment
> about it being too specific. It is too specific to what?
Mmh right, it's fine then.
>
> And how can spi_mem_do_calibration() know what op the flash uses to read
> data? SPI NOR or SPI NAND would know it, but not SPI MEM. That is why we
> pass in that information to spi_mem_do_calibration().
But here the op is "spi-nor wide", I would have expected a
per-device op. But that is not a big deal, that is something that can
also be updated later if needed I guess.
One last question, is there something that mtd_device_register() does
that is really needed for the calibration to work? Otherwise I would
rather prefer to have that calibration happening before the user gets
access to the device.
>
> >
> > > + spi_mem_do_calibration(nor->spimem, &op);
> >
> > A warning/info upon calibration error (not on the absence of the hook)
> > would be nice?
>
> Yes, agreed.
>
> >
> > > +
> > > + return 0;
> > > }
> > >
> > > static int spi_nor_remove(struct spi_mem *spimem)
> >
> > Otherwise I like the overall idea.
>
> Thanks for reviewing.
>
> >
> > Thanks,
> > Miquèl
>
Thanks,
Miquèl
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next prev parent reply other threads:[~2022-05-18 7:20 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 19:12 [RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi Pratyush Yadav
2021-03-11 19:12 ` [RFC PATCH 1/6] spi: spi-mem: Tell controller when device is ready for calibration Pratyush Yadav
2021-03-23 23:07 ` Michael Walle
2021-03-24 8:08 ` Pratyush Yadav
2021-04-29 16:23 ` Michael Walle
2021-04-29 18:41 ` Pratyush Yadav
2021-04-29 22:46 ` Michael Walle
2021-03-11 19:12 ` [RFC PATCH 2/6] mtd: spi-nor: core: consolidate read op creation Pratyush Yadav
2021-03-23 23:17 ` Michael Walle
2021-03-24 8:04 ` Pratyush Yadav
2021-04-08 12:48 ` Michael Walle
2021-03-11 19:12 ` [RFC PATCH 3/6] mtd: spi-nor: core: run calibration when initialization is done Pratyush Yadav
2022-05-17 14:02 ` Miquel Raynal
2022-05-18 6:07 ` Pratyush Yadav
2022-05-18 7:19 ` Miquel Raynal [this message]
2022-05-18 7:56 ` Pratyush Yadav
2022-05-18 8:51 ` Cédric Le Goater
2022-06-27 9:14 ` Pratyush Yadav
2022-06-27 9:43 ` Cédric Le Goater
2022-06-27 10:35 ` Pratyush Yadav
2021-03-11 19:12 ` [RFC PATCH 4/6] spi: cadence-qspi: Use PHY for DAC reads if possible Pratyush Yadav
2021-03-12 9:13 ` Tudor.Ambarus
2021-03-12 10:17 ` Pratyush Yadav
2021-04-29 16:28 ` Michael Walle
2021-04-29 18:19 ` Pratyush Yadav
2021-04-29 22:20 ` Michael Walle
2021-05-10 11:39 ` Pratyush Yadav
2021-03-11 19:12 ` [RFC PATCH 5/6] spi: cadence-qspi: Tune PHY to allow running at higher frequencies Pratyush Yadav
2021-04-29 22:48 ` Michael Walle
2021-04-30 5:42 ` Pratyush Yadav
2021-03-11 19:12 ` [RFC PATCH 6/6] arm64: dts: ti: k3-j721e-som-p0: Enable PHY calibration Pratyush Yadav
2021-03-12 9:09 ` [RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi Tudor.Ambarus
2021-03-12 10:10 ` Pratyush Yadav
2021-03-12 10:20 ` Michael Walle
2021-03-12 11:07 ` Pratyush Yadav
2021-03-12 13:26 ` Michael Walle
2021-03-12 11:23 ` Tudor.Ambarus
2021-03-12 18:14 ` Pratyush Yadav
2021-03-12 13:32 ` Michael Walle
2021-03-12 14:59 ` Tudor.Ambarus
2021-03-12 17:00 ` Pratyush Yadav
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