On Fri, May 27, 2011 at 12:45 AM, Wolfgang Denk wd@denx.de wrote:
Dear Graeme Russ,
In message 4DDF53D3.1060504@gmail.com you wrote:
No. At least not unless you also provide other get_<some unit>_timer() functions which we most likely will not do.
I think you will find most platforms will support get_us_timer() trivially. Those that can't can use get_ms_timer() * 1000 (plus taking wrapping into consideration)
To use common code, we have to assume the "cannot" case, and be prepared to get only millisecond resolution - when can then simply use get_timer() right away and keep the code simple.
Hi Wolfgang,
Can we just assume for a minute that some people want to make use of the microsecond-resolution timers available on some SOC?
If so then we can either say:
1. Sorry, you're on your own, this is an SOC-specific feature and we won't accept patches which use it. Why do you need it anyway, etc.
2. Yes sure, we have a basic framework, please plumb in here.
I would love to see U-Boot take the second approach. It could be as simple as CONFIG_MICROSECOND_TIMER whereupon the library code avoids defining (and the board code must define) get_timer_us(). I don't even believe it needs to be 64-bit, since microsecond timing is obviously not about time of day. Let's keep it simple, but we should have something IMO.
Regards, Simon
Best regards,
Wolfgang Denk
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