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uk.c revision 1.1 
      1 
      2 /*
      3  * Dummy driver for a device we can't identify.
      4  * by Julian Elischer (julian (at) tfs.com)
      5  *
      6  *      $Id: uk.c,v 1.1 1993/11/24 04:52:53 mycroft Exp $
      7  */
      8 
      9 
     10 #include <sys/types.h>
     11 #include <sys/param.h>
     12 #include <sys/errno.h>
     13 #include <sys/ioctl.h>
     14 #include <scsi/scsi_all.h>
     15 #include <scsi/scsiconf.h>
     16 #define NUK 16
     17 
     18 /*
     19  * This driver is so simple it uses all the default services
     20  */
     21 struct scsi_device uk_switch =
     22 {
     23     NULL,
     24     NULL,
     25     NULL,
     26     NULL,
     27     "uk",
     28     0,
     29     0, 0
     30 };
     31 
     32 struct uk_data {
     33 	u_int32 flags;
     34 	struct scsi_link *sc_link;	/* all the inter level info */
     35 } uk_data[NUK];
     36 
     37 #define UK_KNOWN	0x02
     38 
     39 static u_int32 next_uk_unit = 0;
     40 
     41 /*
     42  * The routine called by the low level scsi routine when it discovers
     43  * a device suitable for this driver.
     44  */
     45 errval
     46 ukattach(sc_link)
     47 	struct scsi_link *sc_link;
     48 {
     49 	u_int32 unit, i, stat;
     50 	unsigned char *tbl;
     51 
     52 	SC_DEBUG(sc_link, SDEV_DB2, ("ukattach: "));
     53 	/*
     54 	 * Check we have the resources for another drive
     55 	 */
     56 	unit = next_uk_unit++;
     57 	if (unit >= NUK) {
     58 		printf("Too many unknown devices..(%d > %d) reconfigure kernel\n",
     59 				(unit + 1), NUK);
     60 		return (0);
     61 	}
     62 	/*
     63 	 * Store information needed to contact our base driver
     64 	 */
     65 	uk_data[unit].sc_link = sc_link;
     66 	sc_link->device = &uk_switch;
     67 	sc_link->dev_unit = unit;
     68 
     69 	printf("uk%d: unknown device\n", unit);
     70 	uk_data[unit].flags = UK_KNOWN;
     71 
     72 	return;
     73 
     74 }
     75 
     76 /*
     77  *    open the device.
     78  */
     79 errval
     80 ukopen(dev)
     81 {
     82 	errval  errcode = 0;
     83 	u_int32 unit, mode;
     84 	struct scsi_link *sc_link;
     85 	unit = minor(dev);
     86 
     87 	/*
     88 	 * Check the unit is legal
     89 	 */
     90 	if (unit >= NUK) {
     91 		printf("uk%d: uk %d  > %d\n", unit, unit, NUK);
     92 		return ENXIO;
     93 	}
     94 
     95 	/*
     96 	 * Make sure the device has been initialised
     97 	 */
     98 	if((uk_data[unit].flags & UK_KNOWN) == 0) {
     99 		printf("uk%d: not set up\n", unit);
    100 		return ENXIO;
    101 	}
    102 
    103 	/*
    104 	 * Only allow one at a time
    105 	 */
    106 	sc_link = uk_data[unit].sc_link;
    107 	if (sc_link->flags & SDEV_OPEN) {
    108 		printf("uk%d: already open\n", unit);
    109 		return ENXIO;
    110 	}
    111 	sc_link->flags |= SDEV_OPEN;
    112 	SC_DEBUG(sc_link, SDEV_DB1, ("ukopen: dev=0x%x (unit %d (of %d))\n"
    113 		,dev, unit, NUK));
    114 	/*
    115 	 * Catch any unit attention errors.
    116 	 */
    117 	return 0;
    118 }
    119 
    120 /*
    121  * close the device.. only called if we are the LAST
    122  * occurence of an open device
    123  */
    124 errval
    125 ukclose(dev)
    126 {
    127 	unsigned char unit, mode;
    128 	struct scsi_link *sc_link;
    129 
    130 	sc_link = uk_data[unit].sc_link;
    131 
    132 	SC_DEBUG(sc_link, SDEV_DB1, ("Closing device"));
    133 	sc_link->flags &= ~SDEV_OPEN;
    134 	return (0);
    135 }
    136 
    137 /*
    138  * Perform special action on behalf of the user
    139  * Only does generic scsi ioctls.
    140  */
    141 errval
    142 ukioctl(dev, cmd, arg, mode)
    143 	dev_t   dev;
    144 	u_int32 cmd;
    145 	caddr_t arg;
    146 {
    147 	unsigned char unit;
    148 	struct scsi_link *sc_link;
    149 
    150 	/*
    151 	 * Find the device that the user is talking about
    152 	 */
    153 	unit = minor(dev);
    154 	sc_link = uk_data[unit].sc_link;
    155 	return(scsi_do_ioctl(sc_link,cmd,arg,mode));
    156 }
    157 
    158