On 07/02/2013 09:49 PM, Peter Meerwald wrote: > Hello Jonathan, > >>>>>> the ds1077 is a small, separate chip which can generate a frequency; using >>>>>> IIO I can easily control that frequency from userspace >>>>>> >>>>>> clk seems to be targetted more at integrated clocksources that get >>>>>> activated automatically when needed by other components (maybe I am wrong) >>> >>>>> I think there is a userspace consumer for the clk API in the making. >>> >>> are you referring to this? https://patchwork.kernel.org/patch/2551831/ >>> I'm trying to figure out the status... >> No idea on this I'm afraid, Lars? > > I've been in contact with the person who proposed above patch (Soren); > the proposal was rejected and he is not following up on it to get > it mainline due to lack of time/interest, it is going to be used in his > vendor tree only I've just had a read of the thread. I can see why he gave up on it given the resistence. So what is your usecase for this chip that isn't just providing a clock to some other on board component? (and hence a case where userspace control is necessary) > >>>> Just to jump on the end of this conversation, sorry Peter but this one definitely >>>> looks to me like it belongs clk rather than IIO. If there wasn't a userspace >>>> API in the making, I'd suggest now was the time to propose one as you >>>> clearly have an application for one. >>> >>> fine; so far no reasons were given >>> does that mean iio frequency is deprecated? > >> So as you see it is a bit fuzzy at best, and sometimes I find myself deliberating >> for some time on whether to push a driver in another direction from IIO or not. >> I agreed to the existing frequency drivers on the basis that they didn't fit well >> elsewhere, but if there is now a userspace clock interface in the works, perhaps >> it is time to revisit these. > > thank you for the background information > >>> is there a fundamental difference between hardware supported in iio >>> frequency and the ds1077? > >> Not a clear one, no. The ds1077 to my reading is a very simple example of a programable >> clock but ultimately I 'think' the other two are similar if more complex beasts with >> perhaps rather different target uses. Note that whether they should go in IIO has was >> raised at merge time for them. Honestly I'm more than a little lost in the relevant datasheets. I can verify the code is > > ok, understood > >> If there is a blured edge region where things don't fit in clk but do provide >> functionality that does, then perhaps we need to do a similar job to iio-hwmon? >> This might be true for some of the DDS parts which can be used as clocks, but >> would be a very expensive way of doing that. > > I'll keep looking at clk to see what's going on there (if anything :) > > thanks, regards, p. > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
