[PATCH 2/2] mtd: spi-nor: Add support for flash reset
Michael Walle
michael at walle.cc
Tue Aug 30 00:09:58 PDT 2022
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
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