Hi Guenter, On 21 May 2015 at 23:59, Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > On Thu, May 21, 2015 at 11:46:53PM +0800, Fu Wei wrote: >> Hi Guenter, >> > [ ... ] > >> >> >> + >> >> >> + /* >> >> >> + * Try to determine the frequency from the arch_timer interface >> >> >> + */ >> >> >> + clk = arch_timer_get_rate(); >> >> > >> >> > >> >> > arch_timer_get_rate() does not seem to be exported. Did you try to build >> >> > the driver as module ? >> >> >> >> yes, I have built it as a ko module, that is why I made a patch to >> >> export this interface in the first patch of this patchset >> >> >> >> but I will confirm it again :-) >> >> >> > Guess I'll give it a try myself. I don't really understand how this >> > can work unless arch_timer_get_rate() is exported in your tree. >> >> yes, I have exported it , I think it make sense to export it. >> Because other driver maybe need to get system counter info >> >> Do you agree ? :-) >> > I don't think it is for me to agree or not. The arm maintainers > will need to be involved. You can not just export such a function > without maintainer Ack. yes, I have added Mark Rutland in the CC list when I sent this patchset . He added the "arch_timer_get_rate();" in the arch timer driver. See if he can provide some suggestion. :-) maybe I should add some more arm arch timer maintainers to get more help on this :-) > > Having said that, my personal preference would be for the counter > and rate to be exported through the clock subsystem (ie with > clk_get_rate). But that would still not provide the current counter > value, so maybe that isn't even possible. I will try to make a patch for this, If the arm maintainers don't like exporting "arch_timer_get_rate();" But your thought is good, the clk_get_rate is the best way to do for now > > Thanks, > Guenter -- Best regards, Fu Wei Software Engineer Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch Ph: +86 21 61221326(direct) Ph: +86 186 2020 4684 (mobile) Room 1512, Regus One Corporate Avenue,Level 15, One Corporate Avenue,222 Hubin Road,Huangpu District, Shanghai,China 200021 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
