[PATCH 3.9] Driver for 7-segment displays connected over GPIOs

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Mon Jan 7 12:53:57 EST 2013

Dear Greg Kroah-Hartman,

On Mon, 7 Jan 2013 09:23:40 -0800, Greg Kroah-Hartman wrote:

> > Not having a kernel driver means that gazillions of applications
> > re-invent the same piece of code over and over again, have to hardcode
> > the GPIO numbers for a given piece of hardware, while the kernel
> > abstract all of this very nicely.
> That sounds like a wonderful use of a userspace library to do this
> properly.  Much like libusb does, right?
> I still think as this can be done in userspace, it probably should be.

So that's why we have drivers/usb/misc/usbsevseg.c in the kernel, which
uses sysfs files to output text or numbers on a 7-segment display,
while it could all be done using libusb from userspace? Seems like back
in 2008 you Signed-off-by on the patch adding this driver :-)

Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.

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