[U-Boot] [PATCH v2 16/22] omap4: calculate EMIF register values

Aneesh V
2011-05-17T14:30:09Z

Hi Mans,

On Monday 16 May 2011 02:12 AM, M?ns Rullg?rd wrote:
> Wolfgang Denk<wd@denx.de> writes:
>
>> Dear Aneesh V,
>>
>> In message<1305472900-4004-17-git-send-email-aneesh@ti.com> you wrote:
>>> Calculate EMIF register values based on AC timing parameters
>>> from the SDRAM datasheet and the DDR frequency rather than
>>> using the hard-coded values.
>>>
>>> For a new board the user doen't have to go through the tedious
>>> process of calculating the register values. Instead, just
>>> provide the AC timings from the device data sheet as input
>>> and the driver will automatically calculate the register values.
>>
>> Does it make sense to do this in the driver code? These parameters
>> will never change, so why can we not rather perform the computation
>> only once, at build time, and feed in the respective parameters to the
>> driver?
>
> I agree, there should be no reason for doing this at runtime. I would
> think it possible to do with some C macros.
>

I had a C macro version earlier. But as I have mentioned in my reply to
Wolfgang some of the inputs vary between different revisions of our
silicon. I am doing a run-time identification of the revision and doing
the settings accordingly.

Besides, the forest of MACROs was really ugly.

best regards,
Aneesh