Input driver on 1.15.1 vs. 1.19.6

[Alan Coopersmith]

On 10/9/19 6:05 PM, Software Orchestration wrote:
> Hi, I have a client that has a working serial input driver on Ubuntu 14.04, 
> which is running the Xorg 1.15.1 server.
> 
> I'm tasked with getting this to work on Ubuntu 18.04 which is running Xorg 1.19.6
> 
> In looking at the X.Org Server wiki page:
> 
> https://en.wikipedia.org/wiki/X.Org_Server
> 
> I see that 1.15.1 is not supported anymore, but 1.19.6 still is.

I have no idea who decided what releases to list there as supported, but X.Org
certainly isn't supporting all those releases upstream - though some downstream
distros may be doing so. X.Org itself is mainly maintaining the 1.20 series now:
https://gitlab.freedesktop.org/xorg/xserver/-/branches

> My question is if anything would have changed for the input device driver specs 
> between these versions that would effect a serial input device? This is a touch 
> screen, but it interfaces through serial.

There certainly have been driver API/ABI updates between the two:
https://www.x.org/wiki/XorgModuleABIVersions/

> The code uses xf86ReadSerial() and xf86WriteSerial().

Doesn't look like there's been a whole lot of change there in recent years:
https://gitlab.freedesktop.org/xorg/xserver/commits/master/hw/xfree86/os-support/shared/posix_tty.c

> Are there any examples using the latest Xorg server available? 

Examples of input device drivers for Xorg?

https://gitlab.freedesktop.org/xorg/driver?filter=input

> The sources go back pretty far on 14.04 and I see ifdefs for XFREE86_V3 and 
> XFREE86_V4.

XFREE86_V3 code is almost 20 years out of date now, while XFREE86_V4 code would
be closer to 15 years out of date.

-- 
	-Alan Coopersmith-               alan.coopersmith at oracle.com
	 Oracle Solaris Engineering - https://blogs.oracle.com/alanc