[flashrom] [PATCH] ft2232_spi.c: add frequency divider parameter.

[Samir Ibradžić]

On 2012年03月07日 00:25, Stefan Tauner wrote:
> On Tue, 28 Feb 2012 11:50:37 +0900
> Samir Ibradžić<sibradzic at gmail.com>  wrote:
>
>>> it might be a better idea to let the user specify the actual frequency instead of
>>> the divisor like some other programmers do (serprog and buspirate).
>>
>> Well, it may be more clear to specify exact frequencies, but we may end
>> up with weird set of frequencies for all these large dividers.
>> Maybe it would be better to support a limited set of "standard" dividers
>> and their corresponding frequencies, like:
>>
>> divider | freq
>> --------+--------
>> 2       | 30MHz
>> 4       | 15MHz
>> 6       | 10MHz
>> […]
>> (and so on)
>>
>> But i vote for supporting specific divider after all, one can never know
>> if there is some obscure device out there in the wild that supports only
>> 6365372Hz.
>
> well we could support both actually... selecting the divider as in our
> patch, or alternatively the frequency (if it is not possible print the
> next lower available one)...
>
> anyway this can be done later and i'd like to get this into svn
> now-ish rather than wait for the perfect patch. you do not happen to
> own a logic analyzer that could confirm that the frequency now is
> really what we think it is, do you?

Sorry, no analyzer available here. I can confirm though, that when using 
bigger dividers, data transfer speeds achieved matches the calculated 
frequencies, at least on the device i have here (PicoTAP).

> in any case could you please test the patch i have sent so that we know
> it does not break the programmer completely?

Already tested, seems ok. Anyway, we just need to be careful that the 
patch has zero consequences when "spispeed" option is not used at all.

>
> if you like to work on a followup patch please use "spispeed" as the
> parameter for the frequency because that is the one used in serprog and
> the buspirate already.
>

Do you have any updates, or i can re-base on top of your previous patch?

R,
S