Oops, I didn’t copy the complete config: CONFIG_IIO_DUMMY_EVGEN=m CONFIG_IIO_SIMPLE_DUMMY=m CONFIG_IIO_SIMPLE_DUMMY_EVENTS=y CONFIG_IIO_SIMPLE_DUMMY_BUFFER=y # CONFIG_IIO_SIMPLE_DUMMY_BUFFER_KFIFO is not set CONFIG_IIO_SIMPLE_DUMMY_BUFFER_DMA=y Regards, John > On Feb 22, 2016, at 9:31 AM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > > On 02/22/2016 06:25 PM, John Syne wrote: >> Hi Lars, >> >> It seems like there are other config selections that are selecting KFIFO so it seems to be enabled always. I can enable DMA buffer, but I will see how to disable KFIFO. When I get this working, should I see a waveform in IIO Oscilloscope? > > Hi, > > There is one for the dummy buffer. > > IIO_SIMPLE_DUMMY_BUFFER_DMA needs to be set and > IIO_SIMPLE_DUMMY_BUFFER_KFIFO needs to be unset. > > - Lars > > >> >> Regards, >> John >> >> >> >> >>> On Feb 22, 2016, at 3:44 AM, Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: >>> >>> On 02/22/2016 05:51 AM, John Syne wrote: >>>> BTW, I seem to remember that Lars removed iio_simple_dummy_buffer_dma.c in his V3 patch so this won’t be in the IIO repo, but I don’t know how to test the IIO DMA framework without this file. >>>> >>> >>> Hi, >>> >>> The patch was dropped for now to avoid conflicts with other ongoing work on >>> the dummy driver. The patch will come back in a slightly overhauled version >>> soonish. >>> >>> As for your problem, make sure that you have the part of the patch which >>> updates things so you can choose in Kconfig whether you want to use the DMA >>> buffer or the KFIFO buffer. And then select the DMA buffer in your .config. >>> >>> - Lars >>> >>> >>>> Regards, >>>> John >>>> >>>> >>>> >>>> >>>>> On Feb 21, 2016, at 8:41 PM, 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 >>>>> >>>>> 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 >> > -- 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
