Dear Lars-Peter Clausen, > On 07/19/2012 09:26 PM, Marek Vasut wrote: > > Dear Lars-Peter Clausen, > > > >> On 07/19/2012 04:23 PM, Marek Vasut wrote: > >>> Dear Lars-Peter Clausen, > >>> > >>> Sorry for my late reply, got busy with other crazy stuff. > >>> > >>> [...] > >>> > >>>>>> Is there any reason not to use the mxs_lradc struct directly has the > >>>>>> iio data? > >>>>> > >>>>> I explained it below in the patch. I hope we'll eventually support > >>>>> the delay triggers, which will need 4 separate IIO devices. And this > >>>>> is where this structure will be augmented by other components. > >>>> > >>>> Ok I saw the comment, but it wasn't obvious to me that delay channels > >>>> will require multiple IIO devices. Might make sense to state this > >>>> explicitly. > >>> > >>> Fixed. > >>> > >>>>>>> [...] > >>>>>>> > >>>>>>> + > >>>>>>> +/* > >>>>>>> + * Channel management > >>>>>>> + * > >>>>>>> + * This involves crazy mapping between 8 virtual channels the > >>>>>>> CTRL4 register + * can harbor and 16 channels total this hardware > >>>>>>> supports. + */ > >>>>>> > >>>>>> I suppose this means only a maximum 8 channels can be active at a > >>>>>> time. I've recently posted a patch which makes it easy to implement > >>>>>> such a restriction. > >>>>>> http://www.spinics.net/lists/linux-iio/msg05936.html and > >>>>>> http://www.spinics.net/lists/linux-iio/msg05935.html for an example > >>>>>> validate callback implementation. In your case you'd check for > >>>>>> bitmap_weight(...) <= 8. Those patches are not yet in IIO though. > >>>>> > >>>>> This is good. When do you expect this to hit linux-next possibly? Or > >>>>> at least linux-iio? > >>>> > >>>> soon, hopefully. > >>> > >>> So I checked this, not sure how it'll help me though. > >> > >> Right now with your driver you can enable any combination of channels. > >> If more than 8 channels are enabled and you start sampling it will > >> fail, since not all channels can be mapped. With those patch you can > >> implement a validate callback and check for bitmap_weight(scan_mask) <= > >> 8. This will ensure that it is not possible to select more than 8 > >> channels at once, which again means that starting sampling can't fail > >> of this. > > > > Ok, I fixed this one. One last thing that I don't really understand is > > this. I run generic_buffer.c to source samples from the LRADC. Is there > > any way to continuously sample them? Because right now, I get one sample > > and that's it, no more samples happen later on (I can 0 data in > > subsequent read() call). > > I'd consider that a bug in your driver ;) > The intend with IIO is that once you start sampling by enabling the buffer > you get a continuous data stream until sampling is stopped and this works > fine with other drivers. Ah! Thanks, I'll poke into this. > - Lars Best regards, Marek Vasut -- 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
