Re: [PATCH 23/24] mtd: spinand: winbond: Add comment about naming

[Miquel Raynal <miquel.raynal@xxxxxxxxxxx>]

On 18/12/2024 at 08:14:36 GMT, Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> wrote:

> On 12/13/24 12:25 PM, Miquel Raynal wrote:
>> On 11/11/2024 at 14:38:53 GMT, Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> wrote:
>> 
>>> On 10/25/24 5:15 PM, Miquel Raynal wrote:
>>>> Make the link between the core macros and the datasheet.
>>>>
>>>> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
>>>> ---
>>>>  drivers/mtd/nand/spi/winbond.c | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/drivers/mtd/nand/spi/winbond.c b/drivers/mtd/nand/spi/winbond.c
>>>> index 686e872fe0ff..9e2562805d23 100644
>>>> --- a/drivers/mtd/nand/spi/winbond.c
>>>> +++ b/drivers/mtd/nand/spi/winbond.c
>>>> @@ -18,6 +18,11 @@
>>>>  
>>>>  #define W25N04KV_STATUS_ECC_5_8_BITFLIPS	(3 << 4)
>>>>  
>>>> +/*
>>>> + * "X2" in the core is equivalent to "dual output" in the datasheets,
>>>> + * "X4" in the core is equivalent to "quad output" in the datasheets.
>>>> + */
>>>
>>> doesn't help great for an outsider like me. Is quad referring to cmd,
>>> addr or data? Or maybe of all? I need to read the code anyway.
>> 
>> I also don't like these terms. IIRC "output" is referring to the data cycles,
>> otherwise it means address (dummy) and data cycles.
>> 
>> In single, dual or quad mode the naming is unclear but "okay". But octal
>> DDR modes can require the opcode to be sent in octal mode as well, which
>> is new. If we support that, I'll take care of using a more
>> understandable naming for all macros like Xy-Xy-Xy, X being the
>> buswidth, y being S (sdr) or D (ddr) and the three members being
>
> 8d-8d-8d is common and covered by few standards, yes.
>
>> Command-Address-Data. I might even be tempted to include dummy cycles as
>> well, because it is important to be clear if eg. in octal mode "1" means
>> "1 cycle" or "8 cycles".
> I find the info about dummy cycles useful. I wonder if such terminology
> is already specified in a standard. If not, maybe we can put the dummy
> cycles after the mode, in parenthesis? I would refrain custom terminology.

I see you concern, but would you mind giving an example of what you have
in mind?

Thanks,
Miquèl