2008-02-01 16:16:34 API for GPIO Wakeups

Christopher Harrsen (UNITED STATES)

Message: 50582

I would like to use the API for GPIO wakeups. This is a kernel space API. Does this mean I have to compile my application to run in Kernel space. How do I call these functions from user space?

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2008-02-01 16:49:18 Re: API for GPIO Wakeups

Robin Getz (UNITED STATES)

Message: 50585 Chris:

Just to understand the terminology: _in kernel_ interfaces ( interface between drivers and kernel functions - the "kernel API") are not the kernel to userspace interfaces (the "syscall interface").

You can not use a kernel API from userspace.

You can not run an userspace application in the kernel.

The kernel GPIO API is at:

http://docs.blackfin.uclinux.org/doku.php?id=gpio

But, this has nothing to do with userspace. What you need to do is write a GPIO driver, that exposes this to userspace.

Since this is pretty common - we added a GPIO driver:

http://docs.blackfin.uclinux.org/doku.php?id=sample_gpio_driver

To usethat GPIO from userspace:

http://docs.blackfin.uclinux.org/doku.php?id=sample_gpio_driver#test_the_driver

and have a look at the example code.

-Robin

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2008-02-05 15:47:37 Re: API for GPIO Wakeups

Christopher Harrsen (UNITED STATES)

Message: 50712

Robin:

Do you have user space code examples of using ioctls' to configure specific GPIOs as interrupts? Also, which ioctl calls (or system calls) can I use to put the processor into sleep mode?

Thanks,

Chris

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2008-02-05 17:42:35 Re: API for GPIO Wakeups

Robin Getz (UNITED STATES)

Message: 50716 Chris:

At the moment - it looks like the docs do not reflect the existing code - it might take a day or two to fix up.

I will let you know as soon as it is done.

-Robin

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2008-02-05 20:09:54 Re: API for GPIO Wakeups

Mike Frysinger (UNITED STATES)

Message: 50720 you do not use ioctl's to create interrupt handlers. if you want to use a GPIO as an interrupt source, you currently need to write a kernel driver to do so.

to put the processor to sleep, you use the sysfs interface ... this part should be in the power management document in the wiki.

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2009-01-14 02:26:49 Re: API for GPIO Wakeups

Larry Fiery (UNITED STATES)

Message: 67902

Robin:

The links below say "you've followed a link to a topic that doesn't exist yet.":

http://docs.blackfin.uclinux.org/doku.php?id=sample_gpio_driver

http://docs.blackfin.uclinux.org/doku.php?id=sample_gpio_driver#test_the_driver

-Larry

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2009-01-14 06:17:47 Re: API for GPIO Wakeups