From: Michael Walle <michael@walle.cc>
To: "Potthuri, Sai Krishna" <sai.krishna.potthuri@amd.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>,
Pratyush Yadav <pratyush@kernel.org>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
devicetree@vger.kernel.org, linux-mtd@lists.infradead.org,
linux-kernel@vger.kernel.org, saikrishna12468@gmail.com,
"git (AMD-Xilinx)" <git@amd.com>
Subject: Re: [PATCH 2/2] mtd: spi-nor: Add support for flash reset
Date: Tue, 30 Aug 2022 09:09:58 +0200 [thread overview]
Message-ID: <c7fd841b2244cbe60e174be3babb1607@walle.cc> (raw)
In-Reply-To: <BY5PR12MB425817D90687D37ABDC638EADB799@BY5PR12MB4258.namprd12.prod.outlook.com>
Hi,
Am 2022-08-30 08:32, schrieb Potthuri, Sai Krishna:
>> > + if (ret)
>> > + return ret;
>> > +
>> > + /*
>> > + * Experimental Minimum Chip select high to Reset delay value
>> > + * based on the flash device spec.
>> > + */
>>
>> Which flash device spec?
> I referred some of the qspi, ospi flash vendors datasheets like Micron,
> Macronix, ISSI, gigadevice, spansion.
Please mention here that you've looked at datasheets of different
vendors.
And maybe instead of doing three comments, just one and then the reset
sequence.
>>
>> > + usleep_range(1, 5);
>> > + gpiod_set_value(reset, 0);
>>
>> Mh, is your logic inverted here? If I read the code correctly,
>> you should use a value of 1 to take the device into reset. The
>> device tree should then have a flag "active low", which will
> Reset Sequence which I implemented here is high(1)->low(0)->high(1).
> By doing this sequence (active low), flash device is getting reset,
> this sequence
> is tested using Octal SPI flash device.
How does the device tree property for your look like?
Has it the GPIO_ACTIVE_LOW flag set?
-michael
next prev parent reply other threads:[~2022-08-30 7:10 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-29 9:05 [PATCH 0/2] mtd: spi-nor: Add flash device reset support Sai Krishna Potthuri
2022-08-29 9:05 ` [PATCH 1/2] dt-bindings: mtd: spi-nor: Add reset-gpios property Sai Krishna Potthuri
2022-08-30 9:21 ` Krzysztof Kozlowski
2022-08-30 9:36 ` Michael Walle
2022-08-30 9:48 ` Krzysztof Kozlowski
2022-08-29 9:05 ` [PATCH 2/2] mtd: spi-nor: Add support for flash reset Sai Krishna Potthuri
2022-08-29 10:04 ` Michael Walle
2022-08-30 6:32 ` Potthuri, Sai Krishna
2022-08-30 7:09 ` Michael Walle [this message]
2022-08-30 10:22 ` Potthuri, Sai Krishna
2022-09-01 1:57 ` Takahiro Kuwano
2022-09-01 5:15 ` Potthuri, Sai Krishna
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