From: Pratyush Yadav <p.yadav@ti.com>
To: Michael Walle <michael@walle.cc>
Cc: <Tudor.Ambarus@microchip.com>, <nm@ti.com>, <kristo@kernel.org>,
<robh+dt@kernel.org>, <miquel.raynal@bootlin.com>,
<richard@nod.at>, <vigneshr@ti.com>, <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>,
<lokeshvutla@ti.com>
Subject: Re: [RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi
Date: Fri, 12 Mar 2021 16:37:09 +0530 [thread overview]
Message-ID: <20210312110707.lrabch4ketqyyepn@ti.com> (raw)
In-Reply-To: <676386736df5e5b22e34b0b5af91c894@walle.cc>
On 12/03/21 11:20AM, Michael Walle wrote:
> Am 2021-03-12 11:10, schrieb Pratyush Yadav:
> > There is usually a delay from when the flash drives the data line (IOW,
> > puts a data bit on it) and when the signal reaches the controller. This
> > delay can vary by the flash, board, silicon characteristics,
> > temperature, etc.
>
> Temperature might change over time, but the calibration is only done
> once. I don't know how much influence the temperature actually has, but
> our boards are usually operating from -40°C to +85°C. So there might be
> a possible temperature difference of 125K between actual calibration and
> when the flash is accessed.
The algorithm supports a temperature range of -45 C to +130 C. The
temperature is checked at calibration time and adjustments are made to
make sure the reads work over the entire temperature range [0].
[0] The current implementation does not have a way to query the
temperature from the sensor (see cqspi_get_temp()), so it always assumes
the temperature at calibration time is 45 C. But that can be added later
once the temperature sensor driver is implemented.
--
Regards,
Pratyush Yadav
Texas Instruments Inc.
next prev parent reply other threads:[~2021-03-12 11:08 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 [this message]
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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