Re: iio_simple_dummy_buffer_dma

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Seems like “iio_simple_dummy_configure_buffer_dma" never gets called and that is why the demo doesn’t work.

Regards,
John




> On Feb 21, 2016, at 8:51 PM, John Syne <john3909@xxxxxxxxx> 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.
> 
> 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



[Index of Archives]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Input]     [Linux Kernel]     [Linux SCSI]     [X.org]

  Powered by Linux