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

[Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>]

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.