[PATCH linux v1 0/4] Seven segment display support
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Wed Dec 14 04:45:30 PST 2016
Hello,
On Tue, 13 Dec 2016 23:55:00 -0800, Jaghathiswari Rankappagounder
Natarajan wrote:
> Documentation for the binding which provides an interface for adding clock,
> data and clear signal GPIO lines to control seven segment display.
>
> The platform device driver provides an API for displaying on two 7-segment
> displays, and implements the required bit-banging. The hardware assumed is
> 74HC164 wired to two 7-segment displays.
>
> The character device driver implements the user-space API for letting a user
> write to two 7-segment displays including any conversion methods necessary
> to map the user input to two 7-segment displays.
>
> Adding clock, data and clear signal GPIO lines in the devicetree to control
> seven segment display on zaius platform.
>
> The platform driver matches on the device tree node; the platform driver also
> initializes the character device.
>
> Tested that the seven segment display works properly by writing to the
> character device file on a EVB AST2500 board which also has 74HC164 wired
> to two 7-segment displays.
FWIW, I proposed a driver for seven segment displays back in 2013:
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/139986.html
And the feedback from Greg KH was: we don't need a driver for that, do
it from userspace. See:
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-January/139992.html
So: good luck :-)
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
More information about the linux-arm-kernel
mailing list