Hi, I am interested in using the IIO DMA framework and tried to use your dummy driver. I attempting to get the iio_dummy working with dma and seem to be having sum difficulty. Here is what I have done so far: I’m working on a BeagleBoneBlack running a 4.1 Linux Kernel. I have back ported the latest IIO code from git://git.kernel.org/pub/scm/linux/kernel/git/jic23 As a test I tried ti_am335x_adc.ko and enabled in_voltage0_en and then enabled the buffer. Reading from /dev/iio:device0 provided the waveform of the signal generator I had connected to ADC0 on the board. I was even able to run iiod and then connected IIO Oscilloscope which showed the same waveform. I did get a message WARNING: High-speed mode not enabled, but I guess there is no mmap in the driver and that is probably the issue. In linux config, I have enabled the following: CONFIG_IIO_SIMPLE_DUMMY_EVENTS CONFIG_IIO_SIMPLE_DUMMY_BUFFER CONFIG_IIO_SIMPLE_DUMMY_BUFFER_DMA CONFIG_IIO_BUFFER_CB CONFIG_IIO_BUFFER_DMA CONFIG_IIO_BUFFER_DMAENGINE CONFIG_IIO_KFIFO_BUF CONFIG_IIO_TRIGGERED_BUFFER CONFIG_IIO_TRIGGER CONFIG_IIO_CONSUMERS_PER_TRIGGER 2 When I "modprobe iio_dummy”, the following modules are loaded: industrialio industrialio_buffer_dma iio_dummy kfifo_buf iio_dummy_evgen I then modprobe iio_trig_sysfs which gives me /sys/bus/iio/device/iio_sysfs_trigger. To create a trigger I did: > echo 1 > /sys/bus/iio/device/iio_sysfs_trigger/add_trigger > cat name /sys/bus/iio/device/trigger0/name > sysfstrig1 > echo sysfstrig1 > /sys/bus/iio/device/iio:device0/trigger/current_trigger Now to enable a measurement: > echo 1 > /sys/bus/iio/device/iio:device0/scan_elements/in_voltage0_en Finally to enable the buffer: > echo 1 /sys/bus/iio/device/iio:device0/buffer/enable When I read "/dev/iio:device0" I get nothing. Connecting IIO Oscilloscope I get the following error message: WARNING: High-speed mode not enabled ERROR: Reading from device failed: -110 Client Exited In iio_simple_dummy_buffer_dma.c, I see iio_dummy_dma_source which generates a rect, sine, tri and saw waveforms. Not sure what I need to do to get these waveforms to generate. Is this demo functional? Regards, John -- 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
