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

     /* gsc.c - device driver for handy scanners
      *
      * Current version supports:
      *
      *      - Genius GS-4500
      *
      * Copyright (c) 1995 Gunther Schadow.  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.
     * 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/gsc.c 86011 2001-11-04 08:58:22Z phk $
     *
     */
    
    #include "gsc.h"
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/conf.h>
    #include <sys/malloc.h>
    #include <sys/kernel.h>
    #include <sys/uio.h>
    #include <sys/bus.h>
    
    #include <machine/gsc.h>
    
    #include <i386/isa/isa.h>
    #include <i386/isa/isa_device.h>
    #include <i386/isa/gscreg.h>
    
    #ifndef COMPAT_OLDISA
    #error "The gsc device requires the old isa compatibility shims"
    #endif
    
    /***********************************************************************
     *
     * CONSTANTS & DEFINES
     *
     ***********************************************************************/
    
    #define PROBE_FAIL    0
    #define PROBE_SUCCESS IO_GSCSIZE
    #define ATTACH_FAIL   0
    #define ATTACH_SUCCESS 1
    #define SUCCESS       0
    #define FAIL         -1
    #define INVALID       FAIL
    
    #define DMA1_READY  0x08
    
    #ifdef GSCDEBUG
    #define lprintf(args)                                           \
                    do {                                            \
                            if (scu->flags & FLAG_DEBUG)            \
                                    printf args;                    \
                    } while (0)
    #else
    #define lprintf(args)
    #endif
    
    #define MIN(a, b)       (((a) < (b)) ? (a) : (b))
    
    #define TIMEOUT (hz*15)  /* timeout while reading a buffer - default value */
    #define LONG    (hz/60)  /* timesteps while reading a buffer */
    #define GSCPRI  PRIBIO   /* priority while reading a buffer */
    
    /***********************************************************************
     *
     * LAYOUT OF THE MINOR NUMBER
     *
     ***********************************************************************/
    
    #define UNIT_MASK 0xc0    /* unit gsc0 .. gsc3 */
    #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 0x10    /* output graymap (not implemented yet) */
   #define FRMT_PBM  0x08    /* output pbm format */
   #define FRMT_PGM  0x18
   
   /***********************************************************************
    *
    * THE GEMOMETRY TABLE
    *
    ***********************************************************************/
   
   #define GEOMTAB_SIZE 7
   
   static const struct gsc_geom {
     int dpi;     /* dots per inch */
     int dpl;     /* dots per line */
     int g_res;   /* get resolution value (status flag) */
     int s_res;   /* set resolution value (control register) */
   } geomtab[GEOMTAB_SIZE] = {
     { 100,  424, GSC_RES_100, GSC_CNT_424},
     { 200,  840, GSC_RES_200, GSC_CNT_840},
     { 300, 1264, GSC_RES_300, GSC_CNT_1264},
     { 400, 1648, GSC_RES_400, GSC_CNT_1648},
     {  -1, 1696,          -1, GSC_CNT_1696},
     {  -2, 2644,          -2, GSC_CNT_2544},
     {  -3, 3648,          -3, GSC_CNT_3648},
   };
   
   #define NEW_GEOM { INVALID, INVALID, INVALID, INVALID }
   
   /***********************************************************************
    *
    * THE TABLE OF UNITS
    *
    ***********************************************************************/
   
   struct _sbuf {
     size_t  size;
     size_t  poi;
     char   *base;
   };
   
   struct gsc_unit {
     int channel;            /* DMA channel */
     int data;               /* - video port */
     int stat;               /* - status port */
     int ctrl;               /* - control port */
     int clrp;               /* - clear port */
     int flags;
   #define ATTACHED 0x01
   #define OPEN     0x02
   #define READING  0x04
   #define EOF      0x08
   #define FLAG_DEBUG  0x10
   #define PBM_MODE 0x20
     int     geometry;       /* resolution as geomtab index */
     int     blen;           /* length of buffer in lines */
     int     btime;          /* timeout of buffer in seconds/hz */
     struct  _sbuf sbuf;
     char    ctrl_byte;      /* the byte actually written to ctrl port */
     int     height;         /* height, for pnm modes */
     size_t  bcount;         /* bytes to read, for pnm modes */
     struct  _sbuf hbuf;     /* buffer for pnm header data */
   };
   
   static struct gsc_unit unittab[NGSC];
   
   /* 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!!!
    */
   #define MAX_BUFSIZE 0x3000
   #define DEFAULT_BLEN 59
   
   /***********************************************************************
    *
    * THE PER-DRIVER RECORD FOR ISA.C
    *
    ***********************************************************************/
   
   static  int gscprobe (struct isa_device *isdp);
   static  int gscattach(struct isa_device *isdp);
   
   struct isa_driver gscdriver = {
           INTR_TYPE_TTY,
           gscprobe,
           gscattach,
           "gsc"
   };
   COMPAT_ISA_DRIVER(gsc, gscdriver);
   
   static  d_open_t        gscopen;
   static  d_close_t       gscclose;
   static  d_read_t        gscread;
   static  d_ioctl_t       gscioctl;
   
   #define CDEV_MAJOR 47
   static struct cdevsw gsc_cdevsw = {
           /* open */      gscopen,
           /* close */     gscclose,
           /* read */      gscread,
           /* write */     nowrite,
           /* ioctl */     gscioctl,
           /* poll */      nopoll,
           /* mmap */      nommap,
           /* strategy */  nostrategy,
           /* name */      "gsc",
           /* maj */       CDEV_MAJOR,
           /* dump */      nodump,
           /* psize */     nopsize,
           /* flags */     0,
   };
   
   
   /***********************************************************************
    *
    * LOCALLY USED SUBROUTINES
    *
    ***********************************************************************/
   
   /***********************************************************************
    *
    * lookup_geometry -- lookup a record in the geometry table by pattern
    *
    * The caller supplies a geometry record pattern, where INVALID
    * matches anything. Returns the index in the table or INVALID if
    * lookup fails.
    */
   
   static int
   lookup_geometry(struct gsc_geom geom, const struct gsc_unit *scu)
   {
     struct gsc_geom tab;
     int i;
   
     for(i=0; i<GEOMTAB_SIZE; i++)
       {
         tab = geomtab[i];
   
         if ( ( ( geom.dpi   != INVALID ) && ( tab.dpi   == geom.dpi   ) ) ||
              ( ( geom.dpl   != INVALID ) && ( tab.dpl   == geom.dpl   ) ) ||
              ( ( geom.g_res != INVALID ) && ( tab.g_res == geom.g_res ) ) ||
              ( ( geom.s_res != INVALID ) && ( tab.s_res == geom.s_res ) ) )
           {
             lprintf(("gsc.lookup_geometry: "
                    "geometry lookup found: %ddpi, %ddpl\n",
                    tab.dpi, tab.dpl));
             return i;
           }
       }
   
     lprintf(("gsc.lookup_geometry: "
            "geometry lookup failed on {%d, %d, 0x%02x, 0x%02x}\n",
            geom.dpi, geom.dpl, geom.g_res, geom.s_res));
   
     return INVALID;
   }
   
   /***********************************************************************
    *
    * get_geometry -- read geometry from status port
    *
    * Returns the index into geometry table or INVALID if it fails to
    * either read the status byte or lookup the record.
    */
   
   static int
   get_geometry(const struct gsc_unit *scu)
   {
     struct gsc_geom geom = NEW_GEOM;
   
     lprintf(("gsc.get_geometry: get geometry at 0x%03x\n", scu->stat));
   
     if ( ( geom.g_res = inb(scu->stat) ) == FAIL )
       return INVALID;
   
     geom.g_res &= GSC_RES_MASK;
   
     return lookup_geometry(geom, scu);
   }
   
   /***********************************************************************
    *
    * buffer_allocate -- allocate/reallocate a buffer
    * Now just checks that the preallocated buffer is large enough.
    */
   
   static int
   buffer_allocate(struct gsc_unit *scu)
   {
     size_t size;
   
     size = scu->blen * geomtab[scu->geometry].dpl / 8;
   
     lprintf(("gsc.buffer_allocate: need 0x%x bytes\n", size));
   
     if ( size > MAX_BUFSIZE )
       {
         lprintf(("gsc.buffer_allocate: 0x%x bytes are too much\n", size));
         return ENOMEM;
       }
   
     scu->sbuf.size = size;
     scu->sbuf.poi  = size;
   
     lprintf(("gsc.buffer_allocate: ok\n"));
   
     return SUCCESS;
   }
   
   /***********************************************************************
    *
    * buffer_read -- scan a buffer
    */
   
   static int
   buffer_read(struct gsc_unit *scu)
   {
     int stb;
     int res = SUCCESS;
     int chan_bit;
     char *p;
     int sps;
     int delay;
   
     lprintf(("gsc.buffer_read: begin\n"));
   
     if (scu->ctrl_byte == INVALID)
       {
         lprintf(("gsc.buffer_read: invalid ctrl_byte\n"));
         return EIO;
       }
   
     sps=splbio();
   
     outb( scu->ctrl, scu->ctrl_byte | GSC_POWER_ON );
     outb( scu->clrp, 0 );
     stb = inb( scu->stat );
   
     isa_dmastart(ISADMA_READ, scu->sbuf.base, scu->sbuf.size, scu->channel);
   
     chan_bit = 0x01 << scu->channel;
   
     for(delay=0; !(inb(DMA1_READY) & 0x01 << scu->channel); delay += LONG)
       {
         if(delay >= scu->btime)
           {
             splx(sps);
             lprintf(("gsc.buffer_read: timeout\n"));
             res = EWOULDBLOCK;
             break;
           }
         res = tsleep((caddr_t)scu, GSCPRI | PCATCH, "gscread", LONG);
         if ( ( res == 0 ) || ( res == EWOULDBLOCK ) )
           res = SUCCESS;
         else
           break;
       }
     splx(sps);
     isa_dmadone(ISADMA_READ, scu->sbuf.base, scu->sbuf.size, scu->channel);
     outb( scu->clrp, 0 );
   
     if(res != SUCCESS)
       {
         lprintf(("gsc.buffer_read: aborted with %d\n", res));
         return res;
       }
   
     lprintf(("gsc.buffer_read: invert buffer\n"));
     for(p = scu->sbuf.base + scu->sbuf.size - 1; p >= scu->sbuf.base; p--)
       *p = ~*p;
   
     scu->sbuf.poi = 0;
     lprintf(("gsc.buffer_read: ok\n"));
     return SUCCESS;
   }
   
   /***********************************************************************
    *
    * the main functions
    *
    ***********************************************************************/
   
   /***********************************************************************
    *
    * gscprobe
    *
    * read status port and check for proper configuration:
    *  - if address group matches (status byte has reasonable value)
    *  - if DMA channel matches   (status byte has correct value)
    */
   
   static int
   gscprobe (struct isa_device *isdp)
   {
     int unit = isdp->id_unit;
     struct gsc_unit *scu = unittab + unit;
     int stb;
     struct gsc_geom geom = NEW_GEOM;
   
     scu->flags = FLAG_DEBUG;
   
     lprintf(("gsc%d.probe "
            "on iobase 0x%03x, irq %d, drq %d, addr %p, size %d\n",
            unit,
            isdp->id_iobase,
            isdp->id_irq,
            isdp->id_drq,
            isdp->id_maddr,
            isdp->id_msize));
   
     if ( isdp->id_iobase < 0 )
       {
         lprintf(("gsc%d.probe: no iobase given\n", unit));
         return PROBE_FAIL;
       }
   
     stb = inb( GSC_STAT(isdp->id_iobase) );
     if (stb == FAIL)
       {
         lprintf(("gsc%d.probe: get status byte failed\n", unit));
         return PROBE_FAIL;
       }
   
     scu->data = GSC_DATA(isdp->id_iobase);
     scu->stat = GSC_STAT(isdp->id_iobase);
     scu->ctrl = GSC_CTRL(isdp->id_iobase);
     scu->clrp = GSC_CLRP(isdp->id_iobase);
   
     outb(scu->clrp,stb);
     stb = inb(scu->stat);
   
     switch(stb & GSC_CNF_MASK) {
     case GSC_CNF_DMA1:
       lprintf(("gsc%d.probe: DMA 1\n", unit));
       scu->channel = 1;
       break;
   
     case GSC_CNF_DMA3:
       lprintf(("gsc%d.probe: DMA 3\n", unit));
       scu->channel = 3;
       break;
   
     case GSC_CNF_IRQ3:
       lprintf(("gsc%d.probe: IRQ 3\n", unit));
       goto probe_noirq;
     case GSC_CNF_IRQ5:
       lprintf(("gsc%d.probe: IRQ 5\n", unit));
     probe_noirq:
       lprintf(("gsc%d.probe: sorry, can't use IRQ yet\n", unit));
       return PROBE_FAIL;
     default:
       lprintf(("gsc%d.probe: invalid status byte 0x%02x\n", unit, (u_char) stb));
       return PROBE_FAIL;
     }
   
     if (isdp->id_drq < 0)
       isdp->id_drq = scu->channel;
     if (scu->channel != isdp->id_drq)
       {
         lprintf(("gsc%d.probe: drq mismatch: config: %d; hardware: %d\n",
                 unit, isdp->id_drq, scu->channel));
         return PROBE_FAIL;
       }
   
     geom.g_res = stb & GSC_RES_MASK;
     scu->geometry = lookup_geometry(geom, scu);
     if (scu->geometry == INVALID)
       {
         lprintf(("gsc%d.probe: geometry lookup failed\n", unit));
         return PROBE_FAIL;
       }
     else
       {
         scu->ctrl_byte = geomtab[scu->geometry].s_res;
         outb(scu->ctrl, scu->ctrl_byte | GSC_POWER_ON);
   
         lprintf(("gsc%d.probe: status 0x%02x, %ddpi\n",
                unit, stb, geomtab[scu->geometry].dpi));
   
         outb(scu->ctrl, scu->ctrl_byte & ~GSC_POWER_ON);
       }
   
     lprintf(("gsc%d.probe: ok\n", unit));
   
     scu->flags &= ~FLAG_DEBUG;
   
     return PROBE_SUCCESS;
   }
   
   /***********************************************************************
    *
    * gscattach
    *
    * finish initialization of unit structure
    * get geometry value
    */
   
   static int
   gscattach(struct isa_device *isdp)
   {
     int unit = isdp->id_unit;
     struct gsc_unit *scu = unittab + unit;
   
     scu->flags |= FLAG_DEBUG;
   
     lprintf(("gsc%d.attach: "
            "iobase 0x%03x, irq %d, drq %d, addr %p, size %d\n",
            unit,
            isdp->id_iobase,
            isdp->id_irq,
            isdp->id_drq,
            isdp->id_maddr,
            isdp->id_msize));
   
     printf("gsc%d: GeniScan GS-4500 at %ddpi\n",
            unit, geomtab[scu->geometry].dpi);
   
     /*
      * 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(("gsc%d.attach: buffer allocation failed\n", unit));
         return ATTACH_FAIL;       /* XXX attach must not fail */
       }
     scu->sbuf.size = INVALID;
     scu->sbuf.poi  = INVALID;
   
     scu->blen = DEFAULT_BLEN;
     scu->btime = TIMEOUT;
   
     scu->flags |= ATTACHED;
     lprintf(("gsc%d.attach: ok\n", unit));
     scu->flags &= ~FLAG_DEBUG;
   #define GSC_UID 0
   #define GSC_GID 13
     make_dev(&gsc_cdevsw, unit<<6, GSC_UID, GSC_GID, 0666, "gsc%d", unit);
     make_dev(&gsc_cdevsw, ((unit<<6) + FRMT_PBM),
        GSC_UID,  GSC_GID, 0666, "gsc%dp", unit);
     make_dev(&gsc_cdevsw, ((unit<<6) + DBUG_MASK),
        GSC_UID,  GSC_GID, 0666, "gsc%dd", unit);
     make_dev(&gsc_cdevsw, ((unit<<6) + DBUG_MASK+FRMT_PBM),
        GSC_UID,  GSC_GID, 0666, "gsc%dpd", unit);
   
     return ATTACH_SUCCESS;
   }
   
   /***********************************************************************
    *
    * gscopen
    *
    * set open flag
    * set modes according to minor number
    * don't switch scanner on, wait until first read ioctls go before
    */
   
   static  int
   gscopen  (dev_t dev, int flags, int fmt, struct thread *td)
   {
     struct gsc_unit *scu;
     int unit;
   
     unit = UNIT(minor(dev)) & UNIT_MASK;
     if ( unit >= NGSC )
       {
   #ifdef GSCDEBUG
         /* XXX lprintf isn't valid here since there is no scu. */
         printf("gsc%d.open: unconfigured unit number (max %d)\n", unit, NGSC);
   #endif
         return ENXIO;
       }
     scu = unittab + unit;
     if ( !( scu->flags & ATTACHED ) )
       {
         lprintf(("gsc%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(("gsc%d.open: pbm mode\n", unit));
       break;
     case FRMT_RAW:
       lprintf(("gsc%d.open: raw mode\n", unit));
       scu->flags &= ~PBM_MODE;
       break;
     default:
       lprintf(("gsc%d.open: gray maps are not yet supported", unit));
       return ENXIO;
     }
   
     lprintf(("gsc%d.open: minor %d\n",
            unit, minor(dev)));
   
     if ( scu->flags & OPEN )
       {
         lprintf(("gsc%d.open: already open", unit));
         return EBUSY;
       }
   
     if (isa_dma_acquire(scu->channel))
         return(EBUSY);
   
     scu->flags |= OPEN;
   
     return SUCCESS;
   }
   
   /***********************************************************************
    *
    * gscclose
    *
    * turn off scanner
    * release the buffer
    */
   
   static  int
   gscclose (dev_t dev, int flags, int fmt, struct thread *td)
   {
     int unit = UNIT(minor(dev));
     struct gsc_unit *scu = unittab + unit;
   
     lprintf(("gsc%d.close: minor %d\n",
            unit, minor(dev)));
   
     if ( unit >= NGSC || !( scu->flags & ATTACHED ) )
       {
         lprintf(("gsc%d.read: unit was not attached successfully 0x%04x\n",
                unit, scu->flags));
         return ENXIO;
       }
   
     outb(scu->ctrl, scu->ctrl_byte & ~GSC_POWER_ON);
   
     scu->sbuf.size = INVALID;
     scu->sbuf.poi  = INVALID;
   
     isa_dma_release(scu->channel);
   
     scu->flags &= ~(FLAG_DEBUG | OPEN | READING);
   
     return SUCCESS;
   }
   
   /***********************************************************************
    *
    * gscread
    */
   
   static  int
   gscread  (dev_t dev, struct uio *uio, int ioflag)
   {
     int unit = UNIT(minor(dev));
     struct gsc_unit *scu = unittab + unit;
     size_t nbytes;
     int res;
   
     lprintf(("gsc%d.read: minor %d\n", unit, minor(dev)));
   
     if ( unit >= NGSC || !( scu->flags & ATTACHED ) )
       {
         lprintf(("gsc%d.read: unit was not attached successfully 0x%04x\n",
                unit, scu->flags));
         return ENXIO;
       }
   
     if ( !(scu->flags & READING) )
       {
         res = buffer_allocate(scu);
         if ( res == SUCCESS )
           scu->flags |= READING;
         else
           return res;
   
         scu->ctrl_byte = geomtab[scu->geometry].s_res;
   
         /* initialize for pbm mode */
         if ( scu->flags & PBM_MODE )
           {
             char *p;
             int width = geomtab[scu->geometry].dpl;
   
             sprintf(scu->sbuf.base,"P4 %d %d\n", width, scu->height);
             scu->bcount = scu->height * width / 8;
   
             lprintf(("gsc%d.read: initializing pbm mode: `%s', bcount: 0x%x\n",
                     unit, scu->sbuf.base, scu->bcount));
   
             /* move header to end of sbuf */
             for(p=scu->sbuf.base; *p; p++);
             while(--p >= scu->sbuf.base)
               {
                 *(char *)(scu->sbuf.base + --scu->sbuf.poi) = *p;
                 scu->bcount++;
               }
           }
       }
   
     lprintf(("gsc%d.read(before buffer_read): "
             "size 0x%x, pointer 0x%x, bcount 0x%x, ok\n",
             unit, scu->sbuf.size, scu->sbuf.poi, scu->bcount));
   
     if ( scu->sbuf.poi == scu->sbuf.size )
       if ( (res = buffer_read(scu)) != SUCCESS )
         return res;
   
     lprintf(("gsc%d.read(after buffer_read): "
             "size 0x%x, pointer 0x%x, bcount 0x%x, ok\n",
             unit, scu->sbuf.size, scu->sbuf.poi, scu->bcount));
   
     nbytes = MIN( uio->uio_resid, scu->sbuf.size - scu->sbuf.poi );
   
     if ( (scu->flags & PBM_MODE) )
       nbytes = MIN( nbytes, scu->bcount );
   
     lprintf(("gsc%d.read: transferring 0x%x bytes", unit, nbytes));
   
     res = uiomove(scu->sbuf.base + scu->sbuf.poi, nbytes, uio);
     if ( res != SUCCESS )
       {
         lprintf(("gsc%d.read: uiomove failed %d", unit, res));
         return res;
       }
   
     scu->sbuf.poi += nbytes;
     if ( scu->flags & PBM_MODE ) scu->bcount -= nbytes;
   
     lprintf(("gsc%d.read: size 0x%x, pointer 0x%x, bcount 0x%x, ok\n",
             unit, scu->sbuf.size, scu->sbuf.poi, scu->bcount));
   
     return SUCCESS;
   }
   
   /***********************************************************************
    *
    * gscioctl
    *
    */
   
   static  int
   gscioctl (dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
   {
     int unit = UNIT(minor(dev));
     struct gsc_unit *scu = unittab + unit;
   
     lprintf(("gsc%d.ioctl: minor %d\n",
            unit, minor(dev)));
   
     if ( unit >= NGSC || !( scu->flags & ATTACHED ) )
       {
         lprintf(("gsc%d.ioctl: unit was not attached successfully 0x%04x\n",
                unit, scu->flags));
         return ENXIO;
       }
   
     switch(cmd) {
     case GSC_SRESSW:
       lprintf(("gsc%d.ioctl:GSC_SRESSW\n", unit));
       if ( scu->flags & READING )
         {
           lprintf(("gsc%d:ioctl on already reading unit\n", unit));
           return EBUSY;
         }
       scu->geometry = get_geometry(scu);
       return SUCCESS;
     case GSC_GRES:
       *(int *)data=geomtab[scu->geometry].dpi;
       lprintf(("gsc%d.ioctl:GSC_GRES %ddpi\n", unit, *(int *)data));
       return SUCCESS;
     case GSC_GWIDTH:
       *(int *)data=geomtab[scu->geometry].dpl;
       lprintf(("gsc%d.ioctl:GSC_GWIDTH %d\n", unit, *(int *)data));
       return SUCCESS;
     case GSC_SRES:
     case GSC_SWIDTH:
       lprintf(("gsc%d.ioctl:GSC_SRES or GSC_SWIDTH %d\n",
              unit, *(int *)data));
       { int g;
         struct gsc_geom geom = NEW_GEOM;
         if ( cmd == GSC_SRES )
           geom.dpi = *(int *)data;
         else
           geom.dpl = *(int *)data;
         if ( ( g = lookup_geometry(geom, scu) ) == INVALID )
           return EINVAL;
         scu->geometry = g;
         return SUCCESS;
       }
     case GSC_GHEIGHT:
       *(int *)data=scu->height;
       lprintf(("gsc%d.ioctl:GSC_GHEIGHT %d\n", unit, *(int *)data));
       return SUCCESS;
     case GSC_SHEIGHT:
       lprintf(("gsc%d.ioctl:GSC_SHEIGHT %d\n", unit, *(int *)data));
       if ( scu->flags & READING )
         {
           lprintf(("gsc%d:ioctl on already reading unit\n", unit));
           return EBUSY;
         }
       scu->height=*(int *)data;
       return SUCCESS;
     case GSC_GBLEN:
       *(int *)data=scu->blen;
       lprintf(("gsc%d.ioctl:GSC_GBLEN %d\n", unit, *(int *)data));
       return SUCCESS;
     case GSC_SBLEN:
       lprintf(("gsc%d.ioctl:GSC_SBLEN %d\n", unit, *(int *)data));
       if (*(int *)data * geomtab[scu->geometry].dpl / 8 > MAX_BUFSIZE)
         {
           lprintf(("gsc%d:ioctl buffer size too high\n", unit));
           return ENOMEM;
         }
       scu->blen=*(int *)data;
       return SUCCESS;
     case GSC_GBTIME:
       *(int *)data = scu->btime / hz;
       lprintf(("gsc%d.ioctl:GSC_GBTIME %d\n", unit, *(int *)data));
       return SUCCESS;
     case GSC_SBTIME:
       scu->btime = *(int *)data * hz;
       lprintf(("gsc%d.ioctl:GSC_SBTIME %d\n", unit, *(int *)data));
       return SUCCESS;
     default: return ENOTTY;
     }
   }

Cache object: c8a5f0ac14f0381953279374691a5971