Hi Daniel, Yep, that was a typo in my e-mail, but I did this correctly when entering this command. Thank you for pointing that out. Regards, John > On Feb 22, 2016, at 12:07 AM, Daniel Baluta <daniel.baluta@xxxxxxxxx> wrote: > > On Mon, Feb 22, 2016 at 6:41 AM, John Syne <john3909@xxxxxxxxx> wrote: >> 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 > > Nit: 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? -- 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
