[U-Boot] [PATCH] Move ICS CLK chip frequenty calculation code into a common board library

Kumar Gala
2010-05-22T22:39:59Z

On May 21, 2010, at 3:16 PM, Wolfgang Denk wrote:

> Dear Timur Tabi,
>
> In message <4BF6E5DF.5020306@freescale.com> you wrote:
>>
>>>> So here's a better version of that function that rounds to the nearest
>>>> MHz and is of a proper coding style:
>>>
>>> Why do we need that?
>>
>> Um, because you complained about it?
>
> I mean, why do we need that function? strmhz() already includes
> rounding. Are you really rounding, or cutting off precsion?
>
>> Also, because this is silly:
>>
>> Clock Configuration:
>> CPU0:799.992 MHz, CPU1:799.992 MHz,
>> CCB:399.996 MHz,
>> DDR:299.997 MHz (599.994 MT/s data rate) (Asynchronous), LBC:25 MHz
>>
>> Why display 799.992 MHZ when 800 MHz makes more sense?
>
> Hm... does it really make more sense? Or is it just less precise, or
> do you hush up an error?
>
> 799.992 MHz seems to be 24 * 33,333,000 Hz. Are you sure this is the
> exact quartz frequency on your board? If yes, then the number printed
> should probably remain 799.992 MHz. Or is it 33,333,333 Hz? Or
> 33,000,000 ?

Its a 33,333,000 Hz input crystal so the math is correct. Rounding in the ICS code is wrong.

- k