[U-Boot] RFC Re: [PATCH 1/4] OMAP3 I2C Fix the sampling clock.

Tom
2009-06-17T22:31:18Z

How about something like this ?
It is all done in #define's and follows what the kernel does.

The clocks are
I2C_IP_CLK
I2C_INTERNAL_SAMPLING_CLK

The scll and sclh can be modifed by
I2C_SCLL_TRIM
I2C_SCLH_TRIM

Tom

Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 09:02 Thu 11 Jun , Tom wrote:
>
>> Menon, Nishanth wrote:
>>
>>>> -----Original Message-----
>>>> From: Tom [mailto:Tom.Rix at windriver.com]
>>>> Sent: Wednesday, June 10, 2009 9:44 PM
>>>>
>>>>
>>>>> This is a repeat story of what happened in linux-omap and kernel. We had
>>>>>
>>>>>
>>>> a similar discussion in [1] and related patch [2] to change equations. I
>>>> have the same reservations with this patch:
>>>>
>>>>
>>>>> a) using speed as default does not scale for all board combinations.
>>>>> b) need flexible option to provide scll and sclh on a platform basis.
>>>>> Regards,
>>>>> Nishanth Menon
>>>>> Ref:
>>>>> [1] http://marc.info/?t=123540865900002&r=1&w=2
>>>>> [2] http://marc.info/?l=linux-omap&m=122770723311340&w=2
>>>>>
>>>>>
>>>>>
>>>> Do you think this could be handled with just config files?
>>>> Or maybe like fsl_i2c does by passing clk data through the global_data ?
>>>>
>>>>
>>> #defines in config header file might be a viable option.. Though the gd
>>> might be cleaner I think..
>>>
>>> Regards,
>>> Nishanth Menon
>>>
>>>
>> How about something like this?
>> The timing calculation is moved to a separate function that is weakly
>> aliased to a function that the boards can define? This is similar to
>> led initializing in lib_arm. I have put a stub omap_i2c_timing in
>> zoom1.c to show how the board would do the define.
>>
> use weak function will increase the size of u-boot
> I'll prefer to avoid it when it's possible
> if no board mainline need it I'll prefer to avoid it also
>
> Best Regards,
> J.
>

-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-OMAP3-I2C-Fix-the-sampling-clock.patch
Type: text/x-patch
Size: 0 bytes
Desc: not available
Url : http://lists.denx.de/pipermail/u-boot/attachments/20090617/7bab78c9/attachment.bin