Hi Brandon
I am learning to use the BBB to interface a 802.15.4 radio to BBB without a
MCU between BBB and CC2500. I want to remove the MCU and interface directly
to the Kernel.
So for this i have to service interrupts which will be a gpio interrupt to
BBB if a new packet arrives. So that the
From: neo prag.in...@gmail.com
Reply-To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Date: Saturday, September 13, 2014 at 6:17 AM
To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Subject: Re: [beagleboard] Re: registering asynchronous events on kernel
thread
@googlegroups.com
Subject: Re: [beagleboard] Re: registering asynchronous events on kernel
thread in user space
Hi Brandon
I am learning to use the BBB to interface a 802.15.4 radio to BBB without a
MCU between BBB and CC2500. I want to remove the MCU and interface directly
to the Kernel
:
Subject: Re: [beagleboard] Re: registering asynchronous events on kernel
thread in user space
Hi Brandon
Thanks for the reply.
I will summarize here what i found about controlling a GPIO and about
using interrupts.
1. Using sysfs one can easily control the gpio and using threading can
Hi Brandon
1. I agree with jitter involved with processing interrupts and 100% cpu
usage during polling for the same, so is there no way to let the user-space
know that interrupt has occurred apart from polling ?
2. The reason why i said pseudo-interrupt is because we are polling
OK, one more time. All userspace interrupts work the same, pru, network
driver, *anything*. The process blocks until the interrupt handler unblocks
the process with a semaphore or completion in the kernel. For example, when
you read data for a socket connection, it blocks. When data comes in, the
Hi Brandon
Thanks for the reply.
I will summarize here what i found about controlling a GPIO and about using
interrupts.
1. Using sysfs one can easily control the gpio and using threading can
re-create pseudo-interrupt from user space. Found a useful project called
libsoc
From: neo prag.in...@gmail.com
Reply-To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Date: Wednesday, September 10, 2014 at 5:13 AM
To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Subject: Re: [beagleboard] Re: registering asynchronous events on kernel
thread
pseudo-interrupt from user space
There's nothing pseudo about it. Again, any usual way to have a userspace
application respond to an interrupt will be the exact same. The kernel will
block the userspace process until the interrupt is seen. The only real
alternative is burning up the cpu with
From: Brandon I brandon.ir...@gmail.com
Reply-To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Date: Wednesday, September 10, 2014 at 1:55 PM
To: beagleboard@googlegroups.com beagleboard@googlegroups.com
Subject: Re: [beagleboard] Re: registering asynchronous events on kernel
Hi Kavita
I understood the part of request_threaded_irq() found a sample
implementation here-
http://lxr.free-electrons.com/source/drivers/input/touchscreen/cy8ctmg110_ts.c
for touch controllers.
But did not understand the bit about
In userspace use evetest like application to wait on the
Before you jump into the kernel hole, is there a reason that you're not
using the existing sysfs gpio interface (
https://www.kernel.org/doc/Documentation/gpio/sysfs.txt) for the interrupts?
Using this, if you set the gpio up as an interrupt with the sysfs
interface, you poll() the value file and
May be you can use udev In the
err = request_threaded_irq(pdata-irq, NULL, receive_thread,
pdata-irqflags, interrupt, ir);
In reciever thread
static irqreturn_t receive_threar(int irq, void *context_data)
{
struct data *dh = context_data;
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