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C:/temp/src/j2k/QNX4/driver/sample/main.c

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/*
 * Sample QNX4 Device Driver
 *
 * The purpose of this file is to provide a working QNX4
 * device driver which can be used as the basis for developing
 * "real" drivers. It is assumed that a "real" driver would be
 * interfacing to some "real" hardware somewhere, rather than
 * using stdin/stdout.
 *
 * One point worth mentioning is that "most" hardware drivers
 * will provide input into the Device subsystem directly from
 * the input interrupt handler (see Dev.ser source for an
 * example of this). This sample driver shows how to input
 * data at "process time".
 *
 * On the other hand, it is NOT uncommon for a "real" driver to
 * output data at process time as is the case in this example.
 * (for example Dev.con, Dev.win, Dev.par all output data at
 * process time).
 */


/*
 * This sample driver will read from stdin and write to stderr.
 * if 'DEBUGMODE' is defined. Comment out the next line to use your code
 */
#define DEBUGMODE

#include <sys/types.h>
#include <sys/sched.h>
#include <sys/kernel.h>
#include <sys/proxy.h>
#include <sys/psinfo.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

#include <sys/_devdrvr.h>

#ifdef DEBUGMODE
#include <sys/dev.h>
unsigned old_mode;
#endif

extern int far Kick (struct output_buffer far *obuf);
extern int far Stty (struct termios far *tios); 
extern int far Ctrl (union ioctl_entry far *ioc); 

extern int sys_msg( void * );

union _private_msg {
   msg_t    type;
   msg_t    status;
   char     filer[100];
   } msg;

int idle = 1;
int more = 0;

pid_t out_proxy;
pid_t in_proxy;
pid_t proxy;

unsigned isize = 2048;
unsigned osize = 2048;
unsigned csize = 256;

#define MAX_DEVICES 10

struct driver_ctrl drv_ctrl;
struct device_ctrl ctrl[MAX_DEVICES];
int dev_handle;
int num_devices = 1;
unsigned driver_options = 0;  /* found in <sys/_devdrvr.h> */

char *prefix = "tst";

main(argc, argv)
int argc; char *argv[];
   {
   unsigned c;
   int i;
   pid_t pid;
   int t;
   int nbytes;
   extern void terminate();

   setscheduler(0, SCHED_FIFO, 15);

   /*
    * Allow only SIGTERM, which we catch and cause
    * graceful termination, all others are ignored
    */
   for( i = _SIGMIN; i <= _SIGMAX; ++i)
      if( i != SIGTERM)
         signal( i, SIG_IGN );

   signal( SIGTERM, &terminate );

   /*
    * Scan arguments
    */
   while ((c=getopt(argc,argv,"C:I:O:N:n:")) != -1) {
      switch (c) {

      case 'C':
         csize = strtol(optarg,NULL,0);
         break;

      case 'I':
         isize = strtol(optarg,NULL,0);
         break;

      case 'O':
         osize = strtol(optarg,NULL,0);
         break;

      case 'N':
         prefix = optarg;
         break;

      case 'n':
         num_devices = strtol(optarg,NULL,0);
         if(num_devices > MAX_DEVICES)
            num_devices = MAX_DEVICES;
         break;

         }
      }

   /*
    * Register ourselves with the DEVICE Manager
    */

   if((dev_handle = dev_drvr_register("custom", prefix, num_devices,
               &Kick, &Stty, &Ctrl, &drv_ctrl, driver_options)) == -1) {
      exit(ENFILE);
      }

   /*
    * Allocate the resources for this device
    */

   for(i = 0; i < num_devices; ++i) {
      ctrl[i].isize = isize;
      ctrl[i].osize = osize;
      ctrl[i].csize = csize;
      }

   if(dev_drvr_mount(dev_handle, drv_ctrl.base_tty, num_devices, &ctrl[0])) {
      dev_drvr_shutdown( dev_handle );
      exit(ENOMEM);
      }

   out_proxy = qnx_proxy_attach(0, 0, 0, -1);
   in_proxy = qnx_proxy_attach(0, 0, 0, -1);

#ifndef DEBUGMODE
   /*
    * Close off stdin,stdout,stderr since this process
    * is usually started in sysinit as a background process,
    * by the shell, which typically sets stdin to /dev/null
    * (on the machine we booted from), which ties up resources
    */
   close(0);
   close(1);
   close(2);
#endif

   /*
    * Tell Proc that we will respond to "sin ver" messages
    */
   qnx_pflags( _PPF_SERVER, _PPF_SERVER, 0, 0 );

   /*
    * Initialize termios and queue parameters
    * to whatever defaults make sense for this class of device
    */
   
   for( i = 0; i < num_devices; ++i ) {
      /* struct input_buffer far *ibuf; */
      struct output_buffer far *obuf;
      struct termios far *tios;

      obuf = ctrl[i].obuf;
      obuf->mode |= OUTPUT_XNL;

      tios = ctrl[i].termios;

      tios->c_ispeed = tios->c_ospeed = 9600;

      tios->c_cflag = (CREAD);
      tios->c_oflag = (OPOST);
      tios->c_iflag = (ICRNL|IXON|BRKINT);
      tios->c_lflag = (ICANON|ISIG|ECHO|ECHOE|ECHOK|IEXTEN);

      tios->c_cc[VEOF]  = 0x04;
      tios->c_cc[VEOL]  = 0x00;
      tios->c_cc[VERASE]   = 0x7F;
      tios->c_cc[VINTR] = 0x03;
      tios->c_cc[VKILL] = 0x18;
      tios->c_cc[VQUIT] = 0x00;
      tios->c_cc[VSUSP] = 0x00;
      tios->c_cc[VSTART]   = 0x11;
      tios->c_cc[VSTOP] = 0x13;

      tios->c_cc[VMIN]  = 0x01;
      tios->c_cc[VTIME] = 0x00;
      }

   /*
    * Initialize hardware
    */

   init_driver();


   /*
    * Let DEV call us now
    */
   for(i = 0; i < num_devices; ++i) {
      if(dev_drvr_arm(ctrl[i].tty)) {
         dev_drvr_shutdown( dev_handle );
         exit(ENODEV);
         }
      }


   /*
    * Main loop
    */
   
   for(;;) {
   
      pid = Receive( 0, &msg, sizeof(msg) );

      if(pid == out_proxy) {
         idle = 1;
         /*
          * Output data now available
          */
         flush_output();
         continue;
         }

      if(pid == in_proxy) {
         /*
          * Input data is available
          * NOTE: that this would "normally" be taken care of
          *       by an interrupt handler
          */
         input_ready();
         continue;
         }

      /*
       * Otherwise, process a message from a process
       */

      t = msg.type;
      msg.status = ENOSYS;
      nbytes = sizeof(msg.status);

      switch(t) {

      case 0:
         nbytes = sys_msg(&msg);
         break;

      default:
         break;
         }

      if(nbytes)
         Reply(pid, &msg, nbytes);

      continue;      
      }
   }


void terminate( int signal )
   {
   if(signal) {
      /*
       * Shutdown by signal
       */
      dev_drvr_shutdown( dev_handle );
      /*
       * We should give back any GDT's, etc. that
       * the system doesn't release for us
       */
      exit_driver();
      }
   exit(0);
   }


/*
 * Process all input data in all devices
 * Only return when all input is exhausted.
 * Rely on a subsequent Interrupt (which triggers 'in_proxy') to wake us up.
 */

int input_ready() {
   pid_t proxy;
   int i, n;
   char buf[100];

   proxy = 0;

   /*
    * Scan all devices looking for available data
    */
   for( i = 0; i < num_devices; ++i ) {
      while( (n = get_data(i, &buf[0], sizeof(buf))) > 0 ) {
         if(drv_ctrl.ttim_offset != 0) {
            /*
             * Use multiple character input routine if supported by Dev
             */
            pid_t (far *ttimcall) (int tty, int len, char far *data, unsigned ds);
            ttimcall = MK_FP( FP_SEG(drv_ctrl.tti), drv_ctrl.ttim_offset );
            proxy |= (*ttimcall) (ctrl[i].tty, n, &buf[0], drv_ctrl.tti_ds);
            }
         else {
            /*
             * Must inject character at a time for older Dev's
             */
            int j;
            for(j = 0; j < n; ++j)
               proxy |= (*drv_ctrl.tti) (buf[j], ctrl[i].tty, drv_ctrl.tti_ds);
            }
         }
      }

   /*
    * "wake up" Dev if ANYTHING of interest happened
    */
   if(proxy)
      Trigger(proxy);

   return(0);
   }

/*
 * This function will print forever, only returning
 * when all output buffers are drained
 * Rely on a subsequent Kick() call to wake us up again
 *
 * NOTE: that the memory semaphores 'idle' and 'more' are updated
 *       by the far-call stubs (ie: Kick) to make this work efficiently
 */

flush_output() {
   struct output_buffer far *obuf;
   char far *tail;
   char far *end;
   char far *begin;
   int i, n, size;
   int nothing, unit;
   int expand_newlines;

   for(;;) {
      /*
       * Scan every output queue, looking for something to do
       */
      nothing = 0;
      more = 0;
      for(unit = 0; unit < num_devices; ++unit) {

         obuf = ctrl[unit].obuf;

         /*
          * Process flow control output functions first
          */

         if(obuf->mode & OUTPUT_HFLOW_OFF) {
            obuf->mode &= ~OUTPUT_HFLOW_OFF;
            drop_hw(unit);
            }
   
         if(obuf->mode & OUTPUT_HFLOW_ON) {
            obuf->mode &= ~OUTPUT_HFLOW_ON;
            raise_hw(unit);
            }

         if(obuf->mode & OUTPUT_XOFF) {
            obuf->mode &= ~OUTPUT_XOFF;
            /*
             * Disable input by sending XOFF
                */
            put_data(unit, (char far *) "\023", 1, 0);
            }
   
         if(obuf->mode & OUTPUT_XON) {
            obuf->mode &= ~OUTPUT_XON;
            /*
             * Re-enable input by sending XON
             */
            put_data(unit, (char far *) "\021", 1, 0);
            }
   
         /*
          * Skip if no data characters available
          */

         _disable();
         if(obuf->size == 0  ||
               (obuf->mode & (OUTPUT_STOPPED|OUTPUT_STOPPED_HW)) != 0) {
            _enable();
            ++nothing;
            continue;
            }
         _enable();
   
         if(obuf->discard) {
            /*
             * Discard some (or all) data instead of displaying it
             */
            n = obuf->discard;
            _disable();
            obuf->discard -= n;
            obuf->size -= n;
            _enable();
            i = &obuf->buffer[obuf->length] - obuf->tail;
            if(i > n)
               obuf->tail += n;
            else
               obuf->tail = &obuf->buffer[n-i];
            }

         /*
          * Extract the data from the buffer
          */

         tail = obuf->tail;
         end = &obuf->buffer[obuf->length];
         begin = &obuf->buffer[0];
         size = obuf->size;

         expand_newlines = obuf->mode & OUTPUT_XNL;

         /*
          * Calculate number of chars before wrap-around point
          */
         i = end - tail;
         if(i >= size) { /* No wrap around */
            n = put_data(unit, tail, size, expand_newlines);
            }
         else {
            n = put_data(unit, tail, i, expand_newlines);
            n += put_data(unit, begin, size - i, expand_newlines);
            }

         /*
          * Update the Queue pointers, now that the
          * 'n' bytes of data has been extracted
          */

         _disable();

         if(i > n) /* No wrap around */
            obuf->tail = tail + n;
         else
            obuf->tail = begin + (n-i);
         obuf->size -= n;
         /*
          * Compensate for any flushed data which
          * was in the process of being transmitted
          */
         if(obuf->discard > n)
            obuf->discard -= n;
         else
            obuf->discard = 0;

         _enable();
   
         /*
          * If size of buffer drops below notification threshold,
          * inform DEV of the new information
          */
         _disable();
         if(obuf->size < obuf->bcount) {
            obuf->bcount = 0;
            obuf->action |= ACT_OUTPUT_READY;
            _enable();
            Trigger(drv_ctrl.hw_pid);
            }
         else
            _enable();
         }
   
      /*
       */
      _disable();
      if(nothing >= num_devices  &&  more == 0) {
         idle = 1;
         _enable();
         return;
         }
      else
         _enable();
      }
   }



/*******************************************************************

 Hardware specific functions

 [add "useful" stuff here]

 ******************************************************************/


int init_driver()
   {
#ifdef DEBUGMODE
   old_mode = dev_mode( 0, 0, _DEV_MODES);
   dev_arm( 0, in_proxy, _DEV_EVENT_RXRDY );
#else
   /* Your stuff here */
#endif
   return(0);
   }



int exit_driver()
   {
#ifdef DEBUGMODE
   dev_mode( 0, old_mode, _DEV_MODES);
#else
   /* Your stuff here */
#endif
   return(0);
   }



get_data(int unit, char *buf, int nbytes)
   {
   /*
    * Get (at most) 'nbytes' of data from 'unit' (into 'buf').
    * Return #bytes read.
    */
   int n = 0;

   unit = unit; /* keep compiler happy */

#ifdef DEBUGMODE
   n = dev_read(0, buf, nbytes, 0, 0, 0, 0, 0);
   dev_arm( 0, in_proxy, _DEV_EVENT_RXRDY );
#else
   /* Your stuff here */
#endif

   return(n);
   }



put_data(int unit, char far *buf, int nbytes, int expand_newlines)
   {
   /*
    * Output 'nbytes' of data (in 'buf') to 'unit'.
    * Return #bytes written (before expansion).
    */
#ifdef DEBUGMODE
   int i;
   char c;

   unit = unit; /* keep compiler happy */

   for(i = 0; i < nbytes; ++i) {
      c = *buf++;
      if(expand_newlines  &&  c == '\n')
         write(1, "\r", 1);
      write(1, &c, 1);
      }
#else
   /* Your stuff here */
#endif
   return(nbytes);
   }



void drop_hw(int unit) {
   /*
    * Disable input by dropping Hardware handshaking
    */
   unit = unit; /* keep compiler happy */
#ifndef DEBUGMODE
   /* Your stuff here */
#endif
   }



void raise_hw(int unit) {
   /*
    * Re-enable input by raising Hardware handshaking
    */
   unit = unit; /* keep compiler happy */
#ifndef DEBUGMODE
   /* Your stuff here */
#endif
   }


#if 0

/************************************************************************
 * Sample interrupt handler                                             *
 ************************************************************************/

#include "../_devdrvr.h"
#include <sys/trace.h>
#include <sys/tracecod.h>

/*
 * Stack checking MUST be disabled in irq handlers
 */

#pragma off (check_stack);

pid_t async_int(int irq) {
   extern pid_t (far *tti)(int, int, unsigned); /* from dev_drvr_register */
   extern unsigned tti_ds;                 /* from dev_drvr_register */
   pid_t status = 0;
   unsigned char *data;
   int nbytes = 0;
   int irq_type = 0;
   unsigned short c;
   unsigned iobase = 0;

   switch(irq_type) {

   case 0:  /* Good data received */
      /*
       * receive 'nbytes' of data ponted to by 'data'
       */
      while(nbytes--) {
         c = (unsigned short) *data++;
         status |= (*tti) (c, dev->tty, tti_ds);
         }
      break;

   case 1: /* Bad data - parity error */
      status |= (*tti) (*data | RCV_PARITY, dev->tty, tti_ds);
      Trace1( (long)_TRACE_DEV_SER_PARITY, _TRACE_TRANSIENT, iobase );
      break;

   case 2: /* Bad data - framing error */
      status |= (*tti) (*data | RCV_FRAME, dev->tty, tti_ds);
      Trace1( (long)_TRACE_DEV_SER_FRAME, _TRACE_TRANSIENT, iobase );
      break;

   case 3: /* Bad data - overrun */
      status |= (*tti) (*data | RCV_OVERRUN, dev->tty, tti_ds);
      Trace1( (long)_TRACE_DEV_SER_OVERRUN, _TRACE_TRANSIENT, iobase );
      break;

   case 4: /* Break detected */
      status |= (*tti) (*data | RCV_BREAK, dev->tty, tti_ds);
      break;

   case 5: /* Raised Carrier */
      status |= (*tti) (RCV_CARRIER, dev->tty, tti_ds);
      Trace1( _TRACE_DEV_SER_CARRIER, _TRACE_EXPECTED, dev->iobase );
      break;

   case 6: /* Lost Carrier */
      status |= (*tti) (RCV_HNGUP, dev->tty, tti_ds);
      Trace1( _TRACE_DEV_SER_HUP, _TRACE_EXPECTED, dev->iobase );
      break;

   case 7: /* Resume Transmission (hardware handshaking) */
      status |= (*tti) (RCV_HW_ON, dev->tty, tti_ds);
      break;

   case 8: /* Stop Transmission (hardware handshaking) */
      status |= (*tti) (RCV_HW_OFF, dev->tty, tti_ds);
      break;
      }

   return(status);
   }

#pragma on (check_stack);

#endif

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