FreeBSD/Linux Kernel Cross Reference
sys/i386/isa/asc.c

     /* asc.c - device driver for hand scanners
      *
      * Current version supports:
      *
      *      - AmiScan (Mustek) Color and BW hand scanners (GI1904 chipset)
      *
      * Copyright (c) 1995 Gunther Schadow.  All rights reserved.
      * Copyright (c) 1995,1996,1997 Luigi Rizzo.  All rights reserved.
      *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by Gunther Schadow
     *      and Luigi Rizzo.
     * 4. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    /*
     * $FreeBSD: releng/5.0/sys/i386/isa/asc.c 92252 2002-03-14 01:32:30Z alfred $
     */
    
    #include "asc.h"
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/conf.h>
    #include <sys/proc.h>
    #include <sys/malloc.h>
    #include <sys/kernel.h>
    #include <sys/poll.h>
    #include <sys/selinfo.h>
    #include <sys/uio.h>
    #include <sys/bus.h>
    
    #include <machine/asc_ioctl.h>
    
    #include <i386/isa/isa.h>
    #include <i386/isa/isa_device.h>
    #include <i386/isa/ascreg.h>
    
    #ifndef COMPAT_OLDISA
    #error "The asc device requires the old isa compatibility shims"
    #endif
    
    /***
     *** CONSTANTS & DEFINES
     ***
     ***/
    
    #define PROBE_FAIL    0
    #define PROBE_SUCCESS IO_ASCSIZE
    #define ATTACH_FAIL   0
    #define ATTACH_SUCCESS 1
    #define SUCCESS       0
    #define FAIL         -1
    #define INVALID       FAIL
    
    #define DMA1_READY  0x08
    #define ASCDEBUG
    #ifdef ASCDEBUG
    #       define lprintf if(scu->flags & FLAG_DEBUG) printf
    #else
    #       define lprintf (void)
    #endif
    
    #define TIMEOUT (hz*15)  /* timeout while reading a buffer - default value */
    #define ASCPRI  PRIBIO   /* priority while reading a buffer */
    
    /***
     *** LAYOUT OF THE MINOR NUMBER
     ***/
    
    #define UNIT_MASK 0xc0    /* unit asc0 .. asc3 */
    #define UNIT(x)   (x >> 6)
    #define DBUG_MASK 0x20
    #define FRMT_MASK 0x18    /* output format */
    #define FRMT_RAW  0x00    /* output bits as read from scanner */
    #define FRMT_GRAY 0x1     /* output gray mode for color scanner */
    #define FRMT_PBM  0x08    /* output pbm format */
    #define FRMT_PGM  0x18
    
    /***
    *** THE GEMOMETRY TABLE
    ***/
   
   #define GREY_LINE 826 /* 825, or 826 , or 550 ??? */
   static const struct asc_geom {
     int dpi;     /* dots per inch */
     int dpl;     /* dots per line */
     int bpl;     /* bytes per line */
     int g_res;   /* get resolution value (ASC_STAT) */
   } geomtab[] = {
     { 800, 3312, 414, ASC_RES_800},
     { 700, 2896, 362, ASC_RES_700},
     { 600, 2480, 310, ASC_RES_600},
     { 500, 1656, 258, ASC_RES_500},
     { 400, 1656, 207, ASC_RES_400},
     { 300, 1240, 155, ASC_RES_300},
     { 200, 832, 104, ASC_RES_200},
     { 100, 416, 52, ASC_RES_100},
     { 200, 3*GREY_LINE, 3*GREY_LINE, 0 /* returned by color scanner */},
     { 200, GREY_LINE, GREY_LINE, 0 /* color scanner, grey mode */},
     { INVALID, 416, 52, INVALID } /* terminator */
   };
   
   /***
    *** THE TABLE OF UNITS
    ***/
   
   struct _sbuf {
     size_t  size;
     size_t  rptr;
     size_t  wptr; /* only changed in ascintr */
     size_t  count;
     char   *base;
   };
   
   struct asc_unit {
     long thedev;  /* XXX */
     int base;             /* base address */
     int dma_num;          /* dma number */
     char    dma_byte;       /* mask of byte for setting DMA value */
     char    int_byte;       /* mask of byte for setting int value */
     char    cfg_byte;       /* mirror of byte written to config reg (ASC_CFG). */
     char    cmd_byte;       /* mirror of byte written to cmd port (ASC_CMD)*/
     char   portf_byte;
     int flags;
   #define ATTACHED        0x01
   #define OPEN            0x02
   #define READING         0x04
   #define DMA_ACTIVE      0x08
   #define SLEEPING        0x10
   #define SEL_COLL        0x20
   #define PBM_MODE        0x40
   #define FLAG_DEBUG      0x80
     int     geometry;       /* resolution as geomtab index */
     int     linesize;       /* length of one scan line (from geom.table) */
     int     blen;           /* length of buffer in lines */
     int     btime;          /* timeout of buffer in seconds/hz */
     struct  _sbuf sbuf;
     long    icnt;         /* interrupt count XXX for debugging */
     struct selinfo selp;
     int     height;         /* height, for pnm modes */
     size_t  bcount;         /* bytes to read, for pnm modes */
   };
   
   static struct asc_unit unittab[NASC];                                 
   
   /*** I could not find a reasonable buffer size limit other than by
    *** experiments. MAXPHYS is obviously too much, while DEV_BSIZE and
    *** PAGE_SIZE are really too small. There must be something wrong
    *** with isa_dmastart/isa_dmarangecheck HELP!!!
    ***
    *** Note, must be DEFAULT_BLEN * samples_per_line <= MAX_BUFSIZE
    ***/
   #define MAX_BUFSIZE 0xb000 /* XXX was 0x3000 */
   #define DEFAULT_BLEN 16
   
   /***
    *** THE PER-DRIVER RECORD FOR ISA.C
    ***/
   static int ascprobe (struct isa_device *isdp);
   static int ascattach(struct isa_device *isdp);
   
   struct isa_driver ascdriver = {
           INTR_TYPE_TTY,
           ascprobe,
           ascattach,
           "asc"
   };
   COMPAT_ISA_DRIVER(asc, ascdriver);
   
   static ointhand2_t      ascintr;
   
   static d_open_t         ascopen;
   static d_close_t        ascclose;
   static d_read_t         ascread;
   static d_ioctl_t        ascioctl;
   static d_poll_t         ascpoll;
   
   #define CDEV_MAJOR 71
   
   static struct cdevsw asc_cdevsw = {
           /* open */      ascopen,
           /* close */     ascclose,
           /* read */      ascread,
           /* write */     nowrite,
           /* ioctl */     ascioctl,
           /* poll */      ascpoll,
           /* mmap */      nommap,
           /* strategy */  nostrategy,
           /* name */      "asc",
           /* maj */       CDEV_MAJOR,
           /* dump */      nodump,
           /* psize */     nopsize,
           /* flags */     0,
   };
   
   #define STATIC static
   
   /***
    *** LOCALLY USED SUBROUTINES
    ***
    ***/
   
   /***
    *** get_resolution
    ***    read resolution from the scanner
    ***/
   static void
   get_resolution(struct asc_unit *scu)
   {
       int res, i, delay;
   
       res=0;
       scu->cmd_byte = ASC_STANDBY;
       outb(ASC_CMD, scu->cmd_byte);
       tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascres", hz/10);
       for(delay= 100; (res=inb(ASC_STAT)) & ASC_RDY_FLAG; delay--)
       {
           i = tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascres0", 1);
           if ( ( i == 0 ) || ( i == EWOULDBLOCK ) )
               i = SUCCESS;
           else
               break;
       }
       if (delay==0) {
           lprintf("asc.get_resolution: timeout completing command\n");
           return /*  -1 */;
       }
       /* ... actual read resolution... */
       res &= ASC_RES_MASK;
       for (i=0; geomtab[i].dpi != INVALID; i++) {
           if (geomtab[i].g_res == res) break;
       }
       if (geomtab[i].dpi==INVALID) {
           scu->geometry= i; /* INVALID; */
           lprintf("asc.get_resolution: wrong resolution\n");
       } else {
           lprintf("asc.get_resolution: %d dpi\n",geomtab[i].dpi);
           scu->geometry = i;
       }
       scu->portf_byte=0; /* default */
       if (geomtab[scu->geometry].g_res==0 && !(scu->thedev&FRMT_GRAY)) {
           /* color scanner seems to require this */
           scu->portf_byte=2;
           /* scu->geometry++; */
       }
       scu->linesize = geomtab[scu->geometry].bpl;
       scu->height = geomtab[scu->geometry].dpl; /* default... */
   }
   
   /***
    *** buffer_allocate
    ***    allocate/reallocate a buffer
    ***    Now just checks that the preallocated buffer is large enough.
    ***/
   
   static int
   buffer_allocate(struct asc_unit *scu)
   {
     size_t size, size1;
   
     size = scu->blen * scu->linesize;
   
     lprintf("asc.buffer_allocate: need 0x%x bytes\n", size);
   
     if ( size > MAX_BUFSIZE ) {
         size1=size;
         size= ( (MAX_BUFSIZE+scu->linesize-1) / scu->linesize)*scu->linesize;
         lprintf("asc.buffer_allocate: 0x%x bytes are too much, try 0x%x\n",
             size1, size);
         return ENOMEM;
     }
   
     scu->sbuf.size = size;
     scu->sbuf.rptr  = 0;
     scu->sbuf.wptr  = 0;
     scu->sbuf.count  = 0; /* available data for reading */
   
     lprintf("asc.buffer_allocate: ok\n");
   
     return SUCCESS;
   }
   
   /*** dma_restart
    ***    invoked locally to start dma. Must run in a critical section
    ***/
   static void
   dma_restart(struct asc_unit *scu)
   {
       unsigned char al=scu->cmd_byte;
   
       if (geomtab[scu->geometry].g_res==0) {/* color */
           isa_dmastart(ISADMA_READ, scu->sbuf.base+scu->sbuf.wptr,
               scu->linesize + 90 /* XXX */ , scu->dma_num);
           /*
            * looks like we have to set and then clear this
            * bit to enable the scanner to send interrupts
            */
           outb( ASC_CMD, al |= 4 ); /* seems to disable interrupts */
   #if 0
           outb( ASC_CMD, al |= 8 ); /* ??? seems useless */
   #endif
           outb( ASC_CMD, al &= 0xfb );
           scu->cmd_byte = al;
       } else {                                    /* normal */
       isa_dmastart(ISADMA_READ, scu->sbuf.base+scu->sbuf.wptr,
           scu->linesize, scu->dma_num);
       /*** this is done in sub_20, after dmastart ? ***/  
   #if 0
       outb( ASC_CMD, al |= 4 );
       outb( ASC_CMD, al |= 8 ); /* ??? seems useless */
       outb( ASC_CMD, al &= 0xfb );
       scu->cmd_byte = al;
   #else
       outb( ASC_CMD, ASC_OPERATE); 
   #endif
       }
       scu->flags |= DMA_ACTIVE;
   }
   
   /***
    *** the main functions
    ***/
   
   /*** asc_reset
    ***    resets the scanner and the config bytes...
    ***/
   static void
   asc_reset(struct asc_unit *scu)
   {
     scu->cfg_byte = 0 ; /* clear... */
     scu->cmd_byte = 0 ; /* clear... */
   
     outb(ASC_CFG,scu->cfg_byte);  /* for safety, do this here */
     outb(ASC_CMD,scu->cmd_byte);  /* probably not needed */
     tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascres", hz/10); /* sleep .1 sec */
   
     scu->blen = DEFAULT_BLEN;
     scu->btime = TIMEOUT;
     scu->height = 0 ; /* don't know better... */
   }
   /**************************************************************************
    ***
    *** ascprobe
    ***    read status port and check for proper configuration:
    ***    - if address group matches (status byte has reasonable value)
    ***      cannot check interrupt/dma, only clear the config byte.
    ***/
   static int
   ascprobe (struct isa_device *isdp)
   {
     int unit = isdp->id_unit;
     struct asc_unit *scu = unittab + unit;
     int stb;
   
     scu->base = isdp->id_iobase; /*** needed by the following macros ***/
     scu->flags = FLAG_DEBUG;
   
     if ( isdp->id_iobase < 0 ) {
         lprintf("asc%d.probe: no iobase given\n", unit);
         return PROBE_FAIL;
     }
   
     if ((stb=inb(ASC_PROBE)) != ASC_PROBE_VALUE) {
         lprintf("asc%d.probe: failed, got 0x%02x instead of 0x%02x\n",
             unit, stb, ASC_PROBE_VALUE);
         return PROBE_FAIL;
     }
   
   /*
    * NOTE NOTE NOTE
    * the new AmiScan Color board uses int 10,11,12 instead of 3,5,10
    * respectively. This means that the driver must act accordingly.
    * Unfortunately there is no easy way of telling which board one has,
    * other than trying to get an interrupt and noticing that it is
    * missing. use "option ASC_NEW_BOARD" if you have a new board.
    *
    */
   
   #if ASC_NEW_BOARD
   #define ASC_IRQ_A       10
   #define ASC_IRQ_B       11
   #define ASC_IRQ_C       12
   #else
   #define ASC_IRQ_A       3
   #define ASC_IRQ_B       5
   #define ASC_IRQ_C       10
   #endif
   
     switch(ffs(isdp->id_irq) - 1) {
       case ASC_IRQ_A :
         scu->int_byte = ASC_CNF_IRQ3;
         break;
       case ASC_IRQ_B :
         scu->int_byte = ASC_CNF_IRQ5;
         break;
       case ASC_IRQ_C :
         scu->int_byte = ASC_CNF_IRQ10;
         break;
   #if 0
       case -1:
         scu->int_byte = 0;
         lprintf("asc%d.probe: warning - going interruptless\n", unit);
         break;
   #endif
       default:
         lprintf("asc%d.probe: unsupported INT %d (only 3, 5, 10)\n",
                   unit, ffs(isdp->id_irq) - 1 );
         return PROBE_FAIL;
     }
     scu->dma_num = isdp->id_drq;
     switch(scu->dma_num) {
       case 1:
         scu->dma_byte = ASC_CNF_DMA1;
         break;
       case 3:
         scu->dma_byte = ASC_CNF_DMA3;
         break;
       default:
         lprintf("asc%d.probe: unsupported DMA %d (only 1 or 3)\n", 
                   unit, scu->dma_num);
         return PROBE_FAIL;
     }
     asc_reset(scu);
   /*  lprintf("asc%d.probe: ok\n", unit); */
   
     scu->flags &= ~FLAG_DEBUG;
     scu->icnt = 0;
     return PROBE_SUCCESS;
   }
   
   /**************************************************************************
    ***
    *** ascattach
    ***    finish initialization of unit structure, get geometry value (?)
    ***/
   
   static int
   ascattach(struct isa_device *isdp)
   {
     int unit = isdp->id_unit;
     struct asc_unit *scu = unittab + unit;
   
     isdp->id_ointr = ascintr;
     scu->flags |= FLAG_DEBUG;
     printf("asc%d: [GI1904/Trust Ami-Scan Grey/Color]\n", unit);
   
     /*
      * Initialize buffer structure.
      * XXX this must be done early to give a good chance of getting a
      * contiguous buffer.  This wastes memory.
      */
     scu->sbuf.base = contigmalloc((unsigned long)MAX_BUFSIZE, M_DEVBUF, M_NOWAIT,
                                   0ul, 0xfffffful, 1ul, 0x10000ul);
     if ( scu->sbuf.base == NULL )
       {
         lprintf("asc%d.attach: buffer allocation failed\n", unit);
         return ATTACH_FAIL;       /* XXX attach must not fail */
       }
     scu->sbuf.size = INVALID;
     scu->sbuf.rptr  = INVALID;
   
     scu->flags |= ATTACHED;
   /*  lprintf("asc%d.attach: ok\n", unit); */
     scu->flags &= ~FLAG_DEBUG;
   
       scu->selp.si_flags=0;
   #define ASC_UID 0
   #define ASC_GID 13
     make_dev(&asc_cdevsw, unit<<6, ASC_UID, ASC_GID, 0666, "asc%d", unit);
     make_dev(&asc_cdevsw, ((unit<<6) + FRMT_PBM),
       ASC_UID,  ASC_GID, 0666, "asc%dp", unit);
     make_dev(&asc_cdevsw, ((unit<<6) + DBUG_MASK),
       ASC_UID,  ASC_GID, 0666, "asc%dd", unit);
     make_dev(&asc_cdevsw, ((unit<<6) + DBUG_MASK+FRMT_PBM), 
       ASC_UID, ASC_GID, 0666, "asc%dpd", unit);
     return ATTACH_SUCCESS;
   }
   
   /**************************************************************************
    ***
    *** ascintr
    ***    the interrupt routine, at the end of DMA...
    ***/
   static void
   ascintr(int unit)
   {
       struct asc_unit *scu = unittab + unit;
       int chan_bit = 0x01 << scu->dma_num;
   
       scu->icnt++;
       /* ignore stray interrupts... */
       if ((scu->flags & (OPEN |READING)) != (OPEN | READING) ) {
           /* must be after closing... */
           scu->flags &= ~(OPEN | READING | DMA_ACTIVE | SLEEPING | SEL_COLL);
           return;
       }
       if ( (scu->flags & DMA_ACTIVE) && (inb(DMA1_READY) & chan_bit) != 0) {
           outb( ASC_CMD, ASC_STANDBY);
           scu->flags &= ~DMA_ACTIVE;
                   /* bounce buffers... */
           isa_dmadone(ISADMA_READ, scu->sbuf.base+scu->sbuf.wptr,
               scu->linesize, scu->dma_num);
           scu->sbuf.wptr += scu->linesize;
           if (scu->sbuf.wptr >= scu->sbuf.size) scu->sbuf.wptr=0;
           scu->sbuf.count += scu->linesize;
           if (scu->flags & SLEEPING) {
               scu->flags &= ~SLEEPING;
               wakeup((caddr_t)scu);
           }
           if (scu->sbuf.size - scu->sbuf.count >= scu->linesize) {
               dma_restart(scu);
           }
           if (SEL_WAITING(&scu->selp)) {
               selwakeup(&scu->selp);
           }
       }
   }
   
   /**************************************************************************
    ***
    *** ascopen
    ***    set open flag, set modes according to minor number
    ***    FOR RELEASE:
    ***    don't switch scanner on, wait until first read or ioctls go before
    ***/
   
   STATIC int
   ascopen(dev_t dev, int flags, int fmt, struct thread *td)
   {
     struct asc_unit *scu;
     int unit;
   
     unit = UNIT(minor(dev)) & UNIT_MASK;
     if ( unit >= NASC )
       {
   #ifdef ASCDEBUG
         /* XXX lprintf isn't valid here since there is no scu. */
         printf("asc%d.open: unconfigured unit number (max %d)\n", unit, NASC);
   #endif
         return ENXIO;
       }
     scu = unittab + unit;
     if ( !( scu->flags & ATTACHED ) )
       {
         lprintf("asc%d.open: unit was not attached successfully 0x%04x\n",
                unit, scu->flags);
         return ENXIO;
       }
   
     if ( minor(dev) & DBUG_MASK )
       scu->flags |= FLAG_DEBUG;
     else
       scu->flags &= ~FLAG_DEBUG;
   
     switch(minor(dev) & FRMT_MASK) {
     case FRMT_PBM:
       scu->flags |= PBM_MODE;
       lprintf("asc%d.open: pbm mode\n", unit);
       break;
     case FRMT_RAW:
       lprintf("asc%d.open: raw mode\n", unit);
       scu->flags &= ~PBM_MODE;
       break;
     default:
       lprintf("asc%d.open: gray maps are not yet supported", unit);
       return ENXIO;
     }
     
     lprintf("asc%d.open: minor %d icnt %ld\n", unit, minor(dev), scu->icnt);
   
     if ( scu->flags & OPEN ) {
         lprintf("asc%d.open: already open", unit);
         return EBUSY;
     }
     if (isa_dma_acquire(scu->dma_num))
         return(EBUSY);
   
     scu->flags = ATTACHED | OPEN;      
   
     asc_reset(scu);
     get_resolution(scu);
     return SUCCESS;
   }
   
   static int
   asc_startread(struct asc_unit *scu)
   {
       /*** from here on, things can be delayed to the first read/ioctl ***/
       /*** this was done in sub_12... ***/
     scu->cfg_byte= scu->cmd_byte=0;       /* init scanner */
     outb(ASC_CMD, scu->cmd_byte);
       /*** this was done in sub_16, set scan len... ***/
     outb(ASC_BOH, scu->portf_byte );
     if (geomtab[scu->geometry].g_res==0) {                /* color */
           scu->cmd_byte = 0x00 ;
     } else {
     scu->cmd_byte = 0x90 ;
     }
     outb(ASC_CMD, scu->cmd_byte);
     outb(ASC_LEN_L, scu->linesize & 0xff /* len_low */);
     outb(ASC_LEN_H, (scu->linesize >>8) & 0xff /* len_high */);
       /*** this was done in sub_21, config DMA ... ***/
     scu->cfg_byte |= scu->dma_byte;
     outb(ASC_CFG, scu->cfg_byte);
       /*** sub_22: enable int on the scanner ***/
     scu->cfg_byte |= scu->int_byte;
     outb(ASC_CFG, scu->cfg_byte);
       /*** sub_28: light on etc...***/
     scu->cmd_byte = ASC_STANDBY;
     outb(ASC_CMD, scu->cmd_byte);
     tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascstrd", hz/10); /* sleep .1 sec */
     return SUCCESS;
   }
   
   /**************************************************************************
    ***
    *** ascclose
    ***    turn off scanner, release the buffer
    ***    should probably terminate dma ops, release int and dma. lr 12mar95
    ***/
   
   STATIC int
   ascclose(dev_t dev, int flags, int fmt, struct thread *td)
   {
     int unit = UNIT(minor(dev));
     struct asc_unit *scu = unittab + unit;
   
     lprintf("asc%d.close: minor %d\n",
            unit, minor(dev));
   
     if ( unit >= NASC || !( scu->flags & ATTACHED ) ) {
         lprintf("asc%d.close: unit was not attached successfully 0x%04x\n",
                unit, scu->flags);
         return ENXIO;
     }
       /* all this is in sub_29... */
     /* cli(); */
     outb(ASC_CFG, 0 ); /* don't save in CFG byte!!! */
     scu->cmd_byte &= ~ASC_LIGHT_ON;
     outb(ASC_CMD, scu->cmd_byte);/* light off */
     tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascclo", hz/2); /* sleep 1/2 sec */
     scu->cfg_byte &= ~ scu->dma_byte ; /* disable scanner dma */
     scu->cfg_byte &= ~ scu->int_byte ; /* disable scanner int */
     outb(ASC_CFG, scu->cfg_byte);
       /* --- disable dma controller ? --- */
     isa_dma_release(scu->dma_num);
       /* --- disable interrupts on the controller (sub_24) --- */
   
     scu->sbuf.size = INVALID;
     scu->sbuf.rptr  = INVALID;
   
     scu->flags &= ~(FLAG_DEBUG | OPEN | READING);
     
     return SUCCESS;
   }
   
   static void
   pbm_init(struct asc_unit *scu)
   {
       int width = geomtab[scu->geometry].dpl;
       int l= sprintf(scu->sbuf.base,"P4 %d %d\n", width, scu->height);
       char *p;
   
       scu->bcount = scu->height * width / 8 + l;
   
         /* move header to end of sbuf */
       scu->sbuf.rptr=scu->sbuf.size-l;
       bcopy(scu->sbuf.base, scu->sbuf.base+scu->sbuf.rptr,l);
       scu->sbuf.count = l;
       if (geomtab[scu->geometry].g_res!=0) { /* BW scanner */
       for(p = scu->sbuf.base + scu->sbuf.rptr; l; p++, l--)
           *p = ~*p;
   }
   }
   /**************************************************************************
    ***
    *** ascread
    ***/
   
   STATIC int
   ascread(dev_t dev, struct uio *uio, int ioflag)
   {
     int unit = UNIT(minor(dev));
     struct asc_unit *scu = unittab + unit;
     size_t nbytes;
     int sps, res;
     unsigned char *p;
     
     lprintf("asc%d.read: minor %d icnt %ld\n", unit, minor(dev), scu->icnt);
   
     if ( unit >= NASC || !( scu->flags & ATTACHED ) ) {
         lprintf("asc%d.read: unit was not attached successfully 0x%04x\n",
                unit, scu->flags);
         return ENXIO;
     }
   
     if ( !(scu->flags & READING) ) { /*** first read... ***/
           /* allocate a buffer for reading data and init things */
         if ( (res = buffer_allocate(scu)) == SUCCESS ) scu->flags |= READING;
         else return res;
         asc_startread(scu);
         if ( scu->flags & PBM_MODE ) { /* initialize for pbm mode */
             pbm_init(scu);
         }
     }
     
     lprintf("asc%d.read(before): "
         "sz 0x%x, rptr 0x%x, wptr 0x%x, cnt 0x%x bcnt 0x%x flags 0x%x icnt %ld\n",
             unit, scu->sbuf.size, scu->sbuf.rptr,
             scu->sbuf.wptr, scu->sbuf.count, scu->bcount,scu->flags,
             scu->icnt);
   
     sps=spltty();
     if ( scu->sbuf.count == 0 ) { /* no data avail., must wait */
         if (!(scu->flags & DMA_ACTIVE)) dma_restart(scu);
         scu->flags |= SLEEPING;
         res = tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascread", 0);
         scu->flags &= ~SLEEPING;
         if ( res == 0 ) res = SUCCESS;
     }
     splx(sps); /* lower priority... */
     if (scu->flags & FLAG_DEBUG)
         tsleep((caddr_t)scu, ASCPRI | PCATCH, "ascdly",hz);
     lprintf("asc%d.read(after): "
         "sz 0x%x, rptr 0x%x, wptr 0x%x, cnt 0x%x bcnt 0x%x flags 0x%x icnt %ld\n",
             unit, scu->sbuf.size, scu->sbuf.rptr,
             scu->sbuf.wptr, scu->sbuf.count, scu->bcount,scu->flags,scu->icnt);
   
           /* first, not more than available... */
     nbytes = min( uio->uio_resid, scu->sbuf.count );
           /* second, contiguous data... */
     nbytes = min( nbytes, (scu->sbuf.size - scu->sbuf.rptr) );
           /* third, one line (will remove this later, XXX) */
     nbytes = min( nbytes, scu->linesize );
     if ( (scu->flags & PBM_MODE) )
         nbytes = min( nbytes, scu->bcount );
     lprintf("asc%d.read: transferring 0x%x bytes\n", unit, nbytes);
     if (geomtab[scu->geometry].g_res!=0) { /* BW scanner */
     lprintf("asc%d.read: invert buffer\n",unit);
     for(p = scu->sbuf.base + scu->sbuf.rptr, res=nbytes; res; p++, res--)
           *p = ~*p;
     }
     res = uiomove(scu->sbuf.base + scu->sbuf.rptr, nbytes, uio);
     if ( res != SUCCESS ) {
         lprintf("asc%d.read: uiomove failed %d", unit, res);
         return res;
     }
     
     sps=spltty();
     scu->sbuf.rptr += nbytes;
     if (scu->sbuf.rptr >= scu->sbuf.size) scu->sbuf.rptr=0;
     scu->sbuf.count -= nbytes;
           /* having moved some data, can read mode */
     if (!(scu->flags & DMA_ACTIVE)) dma_restart(scu);
     splx(sps); /* lower priority... */
     if ( scu->flags & PBM_MODE ) scu->bcount -= nbytes;
     
     lprintf("asc%d.read: size 0x%x, pointer 0x%x, bcount 0x%x, ok\n",
             unit, scu->sbuf.size, scu->sbuf.rptr, scu->bcount);
     
     return SUCCESS;
   }
   
   /**************************************************************************
    ***
    *** ascioctl
    ***/
   
   STATIC int
   ascioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
   {
     int unit = UNIT(minor(dev));
     struct asc_unit *scu = unittab + unit;
   
     lprintf("asc%d.ioctl: minor %d\n",
            unit, minor(dev));
   
     if ( unit >= NASC || !( scu->flags & ATTACHED ) ) {
         lprintf("asc%d.ioctl: unit was not attached successfully 0x%04x\n",
                unit, scu->flags);
         return ENXIO;
     }
     switch(cmd) {
     case ASC_GRES:
       asc_reset(scu);
       get_resolution(scu);
       *(int *)data=geomtab[scu->geometry].dpi;
       lprintf("asc%d.ioctl:ASC_GRES %ddpi\n", unit, *(int *)data);
       return SUCCESS;    
     case ASC_GWIDTH:
       *(int *)data=geomtab[scu->geometry].dpl;
       lprintf("asc%d.ioctl:ASC_GWIDTH %d\n", unit, *(int *)data);
       return SUCCESS;    
     case ASC_GHEIGHT:
       *(int *)data=scu->height;
       lprintf("asc%d.ioctl:ASC_GHEIGHT %d\n", unit, *(int *)data);
       return SUCCESS;
     case ASC_SHEIGHT:
       lprintf("asc%d.ioctl:ASC_SHEIGHT %d\n", unit, *(int *)data);
       if ( scu->flags & READING ) { 
           lprintf("asc%d:ioctl on already reading unit\n", unit);
           return EBUSY;
       }
       scu->height=*(int *)data;
       return SUCCESS;
   #if 0  
     case ASC_GBLEN:
       *(int *)data=scu->blen;
       lprintf("asc%d.ioctl:ASC_GBLEN %d\n", unit, *(int *)data);
       return SUCCESS;
     case ASC_SBLEN:
       lprintf("asc%d.ioctl:ASC_SBLEN %d\n", unit, *(int *)data);
       if (*(int *)data * geomtab[scu->geometry].dpl / 8 > MAX_BUFSIZE)
         {
           lprintf("asc%d:ioctl buffer size too high\n", unit);
           return ENOMEM;
         }
       scu->blen=*(int *)data;
       return SUCCESS;
     case ASC_GBTIME:
       *(int *)data = scu->btime / hz;
       lprintf("asc%d.ioctl:ASC_GBTIME %d\n", unit, *(int *)data);
       return SUCCESS;
     case ASC_SBTIME:
       scu->btime = *(int *)data * hz;
       lprintf("asc%d.ioctl:ASC_SBTIME %d\n", unit, *(int *)data);
       return SUCCESS;
   #endif
     default: return ENOTTY;
     }
     return SUCCESS;
   }
   
   STATIC int
   ascpoll(dev_t dev, int events, struct thread *td)
   {
       int unit = UNIT(minor(dev));
       struct asc_unit *scu = unittab + unit;
       int sps;
       int revents = 0;
   
       sps=spltty();
   
       if (events & (POLLIN | POLLRDNORM)) {
           if (scu->sbuf.count >0)
               revents |= events & (POLLIN | POLLRDNORM);
           else {
               if (!(scu->flags & DMA_ACTIVE))
                   dma_restart(scu);
               
               selrecord(td, &scu->selp);
           }
       }
       splx(sps);
       return (revents);
   }

Cache object: e99e50ae54adbc9c5793627b8aa43c31