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uk.c revision 1.2 
      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 1.2 1993/12/17 08:51:13 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 
     15 #include <scsi/scsi_all.h>
     16 #include <scsi/scsiconf.h>
     17 
     18 #define NUK 16
     19 
     20 /*
     21  * This driver is so simple it uses all the default services
     22  */
     23 struct scsi_device uk_switch =
     24 {
     25     NULL,
     26     NULL,
     27     NULL,
     28     NULL,
     29     "uk",
     30     0,
     31     0, 0
     32 };
     33 
     34 struct uk_data {
     35 	u_int32 flags;
     36 	struct scsi_link *sc_link;	/* all the inter level info */
     37 } uk_data[NUK];
     38 
     39 #define UK_KNOWN	0x02
     40 
     41 static u_int32 next_uk_unit = 0;
     42 
     43 /*
     44  * The routine called by the low level scsi routine when it discovers
     45  * a device suitable for this driver.
     46  */
     47 errval
     48 ukattach(sc_link)
     49 	struct scsi_link *sc_link;
     50 {
     51 	u_int32 unit, i, stat;
     52 	unsigned char *tbl;
     53 
     54 	SC_DEBUG(sc_link, SDEV_DB2, ("ukattach: "));
     55 	/*
     56 	 * Check we have the resources for another drive
     57 	 */
     58 	unit = next_uk_unit++;
     59 	if (unit >= NUK) {
     60 		printf("Too many unknown devices..(%d > %d) reconfigure kernel\n",
     61 				(unit + 1), NUK);
     62 		return (0);
     63 	}
     64 	/*
     65 	 * Store information needed to contact our base driver
     66 	 */
     67 	uk_data[unit].sc_link = sc_link;
     68 	sc_link->device = &uk_switch;
     69 	sc_link->dev_unit = unit;
     70 
     71 	printf("uk%d: unknown device\n", unit);
     72 	uk_data[unit].flags = UK_KNOWN;
     73 
     74 	return;
     75 
     76 }
     77 
     78 /*
     79  *    open the device.
     80  */
     81 errval
     82 ukopen(dev)
     83 {
     84 	errval  errcode = 0;
     85 	u_int32 unit, mode;
     86 	struct scsi_link *sc_link;
     87 	unit = minor(dev);
     88 
     89 	/*
     90 	 * Check the unit is legal
     91 	 */
     92 	if (unit >= NUK) {
     93 		printf("uk%d: uk %d  > %d\n", unit, unit, NUK);
     94 		return ENXIO;
     95 	}
     96 
     97 	/*
     98 	 * Make sure the device has been initialised
     99 	 */
    100 	if((uk_data[unit].flags & UK_KNOWN) == 0) {
    101 		printf("uk%d: not set up\n", unit);
    102 		return ENXIO;
    103 	}
    104 
    105 	/*
    106 	 * Only allow one at a time
    107 	 */
    108 	sc_link = uk_data[unit].sc_link;
    109 	if (sc_link->flags & SDEV_OPEN) {
    110 		printf("uk%d: already open\n", unit);
    111 		return ENXIO;
    112 	}
    113 	sc_link->flags |= SDEV_OPEN;
    114 	SC_DEBUG(sc_link, SDEV_DB1, ("ukopen: dev=0x%x (unit %d (of %d))\n"
    115 		,dev, unit, NUK));
    116 	/*
    117 	 * Catch any unit attention errors.
    118 	 */
    119 	return 0;
    120 }
    121 
    122 /*
    123  * close the device.. only called if we are the LAST
    124  * occurence of an open device
    125  */
    126 errval
    127 ukclose(dev)
    128 {
    129 	unsigned char unit, mode;
    130 	struct scsi_link *sc_link;
    131 
    132 	sc_link = uk_data[unit].sc_link;
    133 
    134 	SC_DEBUG(sc_link, SDEV_DB1, ("Closing device"));
    135 	sc_link->flags &= ~SDEV_OPEN;
    136 	return (0);
    137 }
    138 
    139 /*
    140  * Perform special action on behalf of the user
    141  * Only does generic scsi ioctls.
    142  */
    143 errval
    144 ukioctl(dev, cmd, arg, mode)
    145 	dev_t   dev;
    146 	u_int32 cmd;
    147 	caddr_t arg;
    148 {
    149 	unsigned char unit;
    150 	struct scsi_link *sc_link;
    151 
    152 	/*
    153 	 * Find the device that the user is talking about
    154 	 */
    155 	unit = minor(dev);
    156 	sc_link = uk_data[unit].sc_link;
    157 	return(scsi_do_ioctl(sc_link,cmd,arg,mode));
    158 }
    159 
    160