staging panel driver

[Peter Hüwe]

Am Thursday 03 September 2009 20:55:17 schrieb Greg KH:
> On Thu, Sep 03, 2009 at 08:49:08PM +0200, Peter Huewe wrote:
> > >
> > >   while :; do
> > >      read key
> > >      case key in
> > >        'Up') ...
> > >      ...
> > >      esac
> > >      echo "Blah"
> > >   done </dev/keypad >/dev/lcd

>
> Well, if it all can work in userspace using lcdproc, that's great.
>
> As long as everyone agrees that's the best way, I'll be glad to drop the
> driver, just let me know.


Hmm, 
I'm not quite sure myself wether the driver is still useful or not.
The main 'disadvantage' of lcdproc is that you can't use simple shell pipes to 
write something on the display (afaik), but rather you have to talk to the 
LCDd (the lcdproc deamon) using sockets or by using telnet.
So something like echo "test" > /dev/lcd is unfortunately not possible, and 
you can't write something to it from kernelspace directly.

Moreover another thing is, even if you really like writing code with sockets 
(*g*), lcdproc has a rather extensive api [ 
http://lcdproc.sourceforge.net/docs/current-dev.html#language ]
The deamon can handle multiple clients, which each can create multiple pages, 
with different priorities - so it isn't as intuitive as a simple echo "test" 
> /dev/lcd

Example session: (I indented lcdproc's responses)

telnet localhost 13666 
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
hello
	connect LCDproc 0.5.2 protocol 0.3 lcd wid 20 hgt 2 cellwid 5 cellhgt 8
client_set -name Example
	success
screen_add myscreen
	success
	ignore myscreen
	listen myscreen
screen_set myscreen -priority alert
	success
	listen myscreen
widget_add myscreen test title
	success
widget_set myscreen test "hello world"
	success



Regards,
Peter