On 02/22/2016 02:57 PM, Lars-Peter Clausen wrote:
On 02/22/2016 02:07 PM, Gregor Boirie wrote:
On 02/22/2016 12:37 PM, Lars-Peter Clausen wrote:
Add a sysfs file entry for each interrupt trigger instance allowing
userspace to :
* poll for interrupt events ;
Why?
On our platform, several sensors are driven by a dedicated "real-time"
CPU (bare-metal context). This CPU interrupts Linux in a periodic manner
which in turn wakes a user process up to perform sensor fusion.
This sysfs poll support allows the user process to explictly wait for
this dedicated CPU interrupt to fetch data located in RAM then process
them.
So you are only using the IIO trigger in this setup, but no buffers or
devices? If you just want to forward the interrupt to userspace UIO might be
the better solution in this case:
https://www.kernel.org/doc/htmldocs/uio-howto/about.html
- Lars
I forgot to mention I also need the trigger to initiate in-kernel sampling
for other IIO devices. These samples are also retrieved by the process
performing
fusion.
You should still be able to export the interrupt using UIO by sharing the IRQ.
I did not think this UIO framework was as flexible as it is.
It makes the iio-trigger-interrupt patch serie quite useless once UIO is
considered as
a real alternative.
Many thanks for the proposal.
Grégor.
- Lars
--
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
