From: Michael Walle <michael@walle.cc>
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>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Mark Brown <broonie@kernel.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, Lokesh Vutla <lokeshvutla@ti.com>
Subject: Re: [RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi
Date: Fri, 12 Mar 2021 14:32:25 +0100 [thread overview]
Message-ID: <b9450a151cce89cde47b4d6a76c74b32@walle.cc> (raw)
In-Reply-To: <20210311191216.7363-1-p.yadav@ti.com>
Am 2021-03-11 20:12, schrieb Pratyush Yadav:
> The main problem here is telling the controller where to find the
> pattern and how to read it. This RFC uses nvmem cells which point to a
> fixed partition containing the data to do the reads. It depends on [0]
> and [1].
>
> The obvious problem with this is it won't work when the partitions are
> defined via command line. I don't see any good way to add nvmem cells
> to
> command line partitions. I would like some help or ideas here. We don't
> necessarily have to use nvmem either. Any way that can cleanly and
> consistently let the controller find out where the pattern is stored is
> good.
The NXP LS1028A SoC has a similar calibration (although there its done
in hardware it seems) and there the datasheet mentions there are flash
devices which supports a preamble before a read function. The preamble
is then some kind of learning pattern. Did you see a flash which
actually
supports that in the wild? I can't find any publicly available
datasheets
of 8bit I/O SPI NOR flashes.
-michael
next prev parent reply other threads:[~2021-03-12 13:33 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
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 [this message]
2021-03-12 14:59 ` Tudor.Ambarus
2021-03-12 17:00 ` Pratyush Yadav
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