[Linux-parport] ppdev apps compiled on 2.4 fail under 2.6

[rtwas]

Ajay Kumar wrote:
> Hi Robert,
>
> I have used 2.6.13 ppdev back some time. Had written a driver to
> support vendor card with one of the ports being pp and used the
> printing apps available.
>
> Currently i dont have the code or pointers to help you out but is
> there any issue with the driver u r using !!
>
> If struck at any specific point with parport, let me know. My
> knowledge too is limited :-)  Will try to help u, if in my reach.
>
Thank you.


I've included the code I had been using successfully under 2.4 (rh9.0).
I've looked at "drv_generic_parport.c"
provided as a reference by Michael Reinelt. At first glance, I can't see
anything different, except the use of
signals. I'll also point out that my code fails under at least two
different distros:
Fedora 4
SuSE 10.0

So I don't think it's a config issue. I took a closer look at my code
operating under SuSE 10.0 thinking maybe
there was a conflicting demon like *CUPS* or something. I tried doing an
"PPEXCL" (a mode to the code listed here) and found I could'nt get a
"PPCLAIM" after that. I killed the CUPS demon and then was able to get a
an exclusive claim on the port. This did'nt change the result however,
-no io on the port-. Although I did notice what seemed to be some input
activity. It seems to behave as if buffered. Nothing conclusive though,
as I
could not get a repeatable behavior on multible bits of the *status*
register. I'll also point out these tests have
been carried out on multiple machines which *had* been runing rh9.0 and
which had seen successful operation
of the code included in this post.

Thanks for taking a look...

Robert W.





#include <linux/parport.h>
#include <linux/ppdev.h>
#include <fcntl.h>



//.............................................
// control:
//                7  6  5  4  3  2  1  0
// STROBE: -c0                         x
// AUTOFD: -c1                      x
//   INIT:  c2                   x
// SELECT: -c3                x
//  (irq en):              x
//  (dir):              x
//
//.............................................

int fd;  // file descriptor


//******************************************************************************
// initialize sppa system
//******************************************************************************
int
sppa_init()
 {

 extern int fd;
 
 fd = open("/dev/parport0",O_RDWR);
 if (fd == -1)
  {
  perror("open");
  return(-1);
  }
 
 
 if (ioctl(fd,PPCLAIM))
  {
  perror("PPCLAIM");
  close(fd);
  return(-2);
  }

 return(0);
 }
//******************************************************************************

//******************************************************************************
// write to out-port
//******************************************************************************
int
sppa_wport
        (
        unsigned char  data
        )
 {
 extern int fd;

 unsigned char control;

 control = 0x0f & (data ^ 0x0b);
 if (ioctl(fd,PPWCONTROL, &control))  return(-1);

 return(0);
 }
//******************************************************************************
//******************************************************************************
// read from in-port
//******************************************************************************
int
sppa_rport
        (
        unsigned char * data
        )
 {
 extern int fd;
 unsigned char control;

 if (ioctl(fd,PPRSTATUS, &control)) return(-1);;

// *data = 0xf & (control ^ 0x0b);

 *data = 0xf & (control >> 3); // 112005


 return(0);
 }
//******************************************************************************

//******************************************************************************
//******************************************************************************
int
sppa_close()
 {
 extern int fd;

 ioctl (fd, PPRELEASE);

 close(fd);

 return(0);
 }
//******************************************************************************