On 04/13/2013 06:34 PM, Devin Heitmueller wrote:
On Sat, Apr 13, 2013 at 11:30 AM, Frank Schäfer
<fschaefer.oss@xxxxxxxxxxxxxx> wrote:
I've checked the documentation about the gpio and led frameworks a few
weeks ago to find out if it makes sense to use them for the
gpio/buttons/led stuff of the VAD Laplace webcam.
AFAICS, there are no benfits as long as you are dealing with these
things internally. It just increases the code size and adds an
additional dependency in this case.
Of course, the situation is different when there is an interaction with
other modules or userspace. In that case using gpiolib could make sense.
I don't know which case applies to the LAN stuff, but for the
buttons/leds it's the first case.
IMHO, it would be a bad idea to expose the actual GPIOs to userspace.
Improperly setting the GPIOs can cause damage to the board, and all of
the functionality that the GPIOs control are exposed through other
much better supported interfaces. It's a nice debug feature for
driver developers who want to hack at the driver, but you really don't
want any situation where end users or applications are making direct
use of the GPIOs.
Existing userspace sysfs interface is clearly debug interface. You will
need root privileges to mount it and IIRC it was not even compiled by
default (needs Kconfig debug option?).
regards
Antti
--
http://palosaari.fi/
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