linux-kernel - Re: [PATCH 01/21] mtd: spinand: Use more specific naming for the reset op

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Message-ID: <4d36e51f-323c-451c-afeb-a6e378e3ed53@linaro.org>
Date: Thu, 20 Mar 2025 12:03:33 +0000
From: Tudor Ambarus <tudor.ambarus@...aro.org>
To: Miquel Raynal <miquel.raynal@...tlin.com>
Cc: Richard Weinberger <richard@....at>, Vignesh Raghavendra
 <vigneshr@...com>, Santhosh Kumar K <s-k6@...com>,
 Pratyush Yadav <pratyush@...nel.org>, Michael Walle <michael@...le.cc>,
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
 Steam Lin <stlin2@...bond.com>, linux-mtd@...ts.infradead.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH 01/21] mtd: spinand: Use more specific naming for the
 reset op



On 3/20/25 11:31 AM, Miquel Raynal wrote:
> 
>>>> How do you feel about a OP-An-Bn-Cn-transaction-format,
>>>> 	where A, B, C is {1, 2, 4, 8}
>>>> 	n is {S, D}
>>>> 	transaction format is {0,1,2,3}{A,B,C,...}
>>>>
>>>> Care must be taken care of at the transaction format, as I see there are
>>>> a few, depending on the xSPI profile and protocol mode.
>>>
>>> I must admit I really dislike the transaction format abbreviation because
>>
>> I'm not in love with the "transaction format" either.
>>
>>> it is specific to a spec we do not follow and is not explicit. I have a
>>> strong preference towards keeping just "An-Bn-Cn", like I did in this
>>
>> Okay.
>>
>>> series. If people are in doubt, they can check what is in the op, it is
>>> self explanatory. I chose this in the first place because it is more
>>> explicit than just "An" which may feel like a cropped
>>> acronym. Furthermore, most octal capable datasheets I've looked at seem
>>> to use the "An-Bn-Cn" format, even for single opcodes.
>>
>> So for RESET, WREN, WRDI and other opcodes that don't require address
>> and data, are those datasheets referring to these opcodes as 1-1-1 commands?
>> Can you point me to one of these datasheets, please?
> 
> All Winbond datasheets use this convention:
> https://www.winbond.com/export/sites/winbond/datasheet/W35N01JW_Datasheet_Brief.pdf
> See 7.1.2 Instruction Set Table p.25.
> 

Nice, thanks!

> I checked Macronix and Gigadevice datasheets, they simply never "name"
> these opcodes clearly.

okay

> 
>> In SPI NOR, WREN is just WREN, regardless of the number of lines it is
>> sent on, 1, 4, or 8. How would you model it here, 1-0-0, 4-0-0, 8-0-0
>> using the same opcode?
> 
> I guess, yes.
> 
>>> So unless there are strong arguments against, I'd prefer to keep the
>>> current formatting. TBH, it is not set in stone and can still evolve
>>> later if that's needed.
>>
>> I find the naming scheme An-Bn-Cn good, I'm arguing that it's not needed
>> everywhere, opcode only commands are better off with it, I think.
> 
> Ok, I can drop the -0-0 in this case if you prefer.

Not needed. Just wanted to make sure we have a unified way of dealing
with the protocol modes. Having WREN-1-0-0 and WREN-8d-0-0 is not that
bad after all, it allows you to specify the number of lines directly,
without mangling the op afterwards.

Reviewed-by: Tudor Ambarus <tudor.ambarus@...aro.org>

Thanks for the patience. I'll check the other patches next week.
Cheers,
ta