User Space GPIO Interrupt programming - GSoC-2018

[Vladimir]

Are you going to poll encoders same way? I need interface encoders too.
BBB has dedicated eQEP hardware, but it seems to be difficult to run
eQEP under freebsd. So I thinking about PRU for handling encoders.

2020-11-24 23:45, Dr. Rolf Jansen пишет:
>> Am 24.11.2020 um 17:32 schrieb Ian Lepore <ian at freebsd.org>:
>>
>> On Tue, 2020-11-24 at 17:14 -0300, Dr. Rolf Jansen wrote:
>>> Hello
>>>
>>> Has anything of the GSoC-2018 efforts made it into the current code
>>> base?
>>>
>>>
>> https://wiki.freebsd.org/SummerOfCode2018Projects/UserSpaceGPIOinterrupts
>>>
>>> I installed the recent 13.0-CURRENT snapshot (2020-11-19) on a
>>> BeagleBone Black which was one of the implementation targets of said
>>> project, but when running the test tools, I either see cannot
>>> read/kevent/poll/aio_read - Operation not supported by device or
>>> Inappropriate ioctl for device.
>>>
>>> Perhaps I need to pull the project’s changes into the kernel by
>>> myself. However, before this I would like to ask whether it is worth
>>> the effort.
>>>
>>> Please, can anyone shed some light on this.
>>>
>>> Best regards
>>>
>>> Rolf
>>>
>>
>> I have had that webpage open (but docked) for literally a year,
>> eternally hoping that I can find time to get to it and somehow get it
>> committed, or maybe use it as the basis for something to be committed
>> (I haven't even looked at it close enough to see if it's commit-quality 
>> code or what).
>>
>> I'm curious: What particular need do you have for userspace gpio
>> interrupts?  What would you like the API to look like (do you like the
>> things listed at that page, or would you prefer something else)?
>>
>> Interrupts is probably not a good name, because it isn't really going
>> to act like an interrupt does for kernel code.  It's really just pin-
>> change notifications delivered to userland.
> 
> I was asked to jump into a project where push buttons and pulses from a rotary encoder (all connected to GPIO's) would invoke some programmed actions. Polling the GPIO's would be too faulty. To me "pin-change notifications delivered to userland" sounds not too bad for my purpose. However, I won't say no for a real threaded GPIO interrupt handler facility, which presumably would serve perfectly as well.
> 
> Thank you for answering
> 
> Best regards
> 
> Rolf
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-- 
With best regards,
Vladimir Goncharov