[U-Boot-Users] Please pull u-boot-83xx.git (I2C rework)
Tolunay Orkun
listmember at orkun.us
Tue Nov 28 22:09:07 CET 2006
Wolfgang Denk wrote:
> In message <1164737878.31193.38.camel at saruman.qstreams.net> you wrote:
>>> Can you be more specific? These two macros are defined in a variety of ways in
>>> U-Boot. Soft I2C is not used on any Freescale parts (AFAIK).
>>>
>> While it's not used on any Freescale evaluation boards, it could
>> certainly be implemented on boards with Freescale CPUs. I'm not sure
>> why you'd bit-bang I2C if you have nice hardware controllers, but there
>
> ...because the bitbanging code is much smaller and easier to
> implement and debug than the code that uses the HW controller?
>
>> may be situations where this makes sense. On the other hand, I don't
>> know if SOFT_I2C and HARD_I2C can co-exist.
>
> No, theu=y are exclusive. But it should be possible to select any of
> these interfaces.
How do we handle the case that there is one hard I2C interface and
another soft I2C interface (bus) via a pair of GPIO port pins? I have a
PPC405EP based custom board that has such a case and I was looking
forward to enabling multiple I2C bus support in U-Boot via both SOFT_I2C
as well as HARD_I2C defined.
Tolunay
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