Hi Arnd,
2015-10-16 0:17 GMT+09:00 Arnd Bergmann <arnd@xxxxxxxx>:
> On Thursday 15 October 2015 18:05:33 Masahiro Yamada wrote:
>> + aliases {
>> + serial0 = &serial0;
>> + serial1 = &serial1;
>> + serial2 = &serial2;
>> + i2c0 = &i2c0;
>> + i2c4 = &i2c4;
>> + i2c5 = &i2c5;
>> + i2c6 = &i2c6;
>>
>
> This looks like a typo, you probably mean
>
> i2c0 = &i2c0;
> i2c1 = &i2c4;
> i2c2 = &i2c5;
> i2c3 = &i2c6;
>
> Can you re-send this?
>
No, it is not a typo, but intentional.
i2c0 - i2c3 are connected to the pads of the SoC package.
On the other hand, i2c-4 - i2c-6 are connected to
internal devices inside the SoC package.
i2c-4 - i2c-6 are always connected to the same hardware
devices and always used for the same purpose.
My expected scenario is:
[1] i2c0 - i2c3 are connected to the on-board devices
depending on board variants.
On some boards, their status is "okay" and
on some boards, their status is "disabled".
[2] i2c4 - i2c6 are always used to communicate
with in-package devices. The status is always "okay".
[3] Some user-land applications may want to have access
through the same character devices,
/dev/i2c4, /dev/i2c5, /dev/i2c6
If your way is adopted,
the real hardware "i2c4" might be aligned to /dev/i2c1 on some boards,
and /dev/i2c2 on others, etc.
--
Best Regards
Masahiro Yamada
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