Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote: >Hi list, > >I'm currently trying to test the buffer output, using the chrdev >present >at /dev/iio:deviceN. > >So I looked into the generic_buffer.c file which seems to do exactly >that. > >By looking into the source code, my understanding is that samples are >stored with this frame format : > >+--bpe--+--...--+--bpe--+--64 bits--+ >| Ch 0 | ..... | Ch N | timestamp | >+-------+-------+-------+-----------+ > >the overall "frame" size being stored in >/sys/..../buffer/bytes_per_datum. > >Now, when I execute generic-buffer, it sets up correctly the driver by >enabling the channels, the buffer, setting the trigger, etc, but >outputs >nothing at all. After some number of trigger firing, it finally exits, >having displayed nothing but > ># /root/generic-buffer -n at91_adc -t at91_adc-dev0-external >iio device number being used is 0 >iio trigger number being used is 3 >/sys/bus/iio/devices/iio:device0 at91_adc-dev0-external ># > >which seems pretty odd to me. > >But when I do a cat directly on /dev/iio:device0, I get some binary >data, which indicates that the buffer is filled anyway. > >So, is generic_buffer supposed to print something ? If so, what kind of >output should I expect ? >Or is it just a poor driver configuration/data storing from me ? Probably something about the data format that it doesn't understand. It is pretty dumb so I would guess you are hitting something it doesn't know about yet. > >Thanks, >Maxime > >-- >Maxime Ripard, Free Electrons >Kernel, drivers, real-time and embedded Linux >development, consulting, training and support. >http://free-electrons.com >-- >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 -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. -- 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
