[PATCH v4 00/20] eeprom: at24: Add OF device ID table
Javier Martinez Canillas
javier at dowhile0.org
Mon May 22 12:39:02 PDT 2017
Hello Geert,
On Mon, May 22, 2017 at 9:30 PM, Geert Uytterhoeven
<geert at linux-m68k.org> wrote:
> Hi Javier,
>
> On Mon, May 22, 2017 at 7:15 PM, Javier Martinez Canillas
> <javier at dowhile0.org> wrote:
>>>> I also wonder why this is really needed if AFAIU "renesas,24c02" is
>>>> compatible with "atmel,24c02". IOW, the driver doesn't need to
>>>> differentiate between the two since the devices are the same and will
>>>> always match using "atmel,24c02".
>>>
>>> It is needed, so that when a difference is found, it can be handled
>>> without updating the DT.
>>
>> Yes, I understand this. What I tried to ask is if there could really
>> be a difference for the same chip type between different vendors, or
>> is just that people were using other manufacturers in the compatible
>> string as a consequence of the DT binding doc and the I2C core
>> ignoring the vendor prefix.
>
> The devices from different vendors are not the same. They contain FLASH
> ROM of a specific size, and glue logic to expose an i2c slave
> interface providing
> an AT24-compatible command set. They should behave similar within
> the limits of the AT24 "spec". But the actual implementation may be different.
>
I see, really appreciate your explanation. I'm not familiar with these
devices and driver but the patch-series are needed in order to make
sure that no regressions will happen once the I2C core reports a
proper OF modalias.
>> I don't mind though, I will leave the manufacturers that are different
>> than the atmel variants in the mainline DTS as you and Geert asked.
>
> OK, thanks!
>
Thanks a lot for your feedback!
> Gr{oetje,eeting}s,
>
> Geert
>
> --
Best regards,
Javier
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