drivers/dio/dio.c

   1 /* Code to support devices on the DIO (and eventually DIO-II) bus
   2  * Copyright (C) 05/1998 Peter Maydell <pmaydell@chiark.greenend.org.uk>
   3  *
   4  * This code has basically these routines at the moment:
   5  * int dio_find(u_int deviceid)
   6  *    Search the list of DIO devices and return the select code
   7  *    of the next unconfigured device found that matches the given device ID.
   8  *    Note that the deviceid parameter should be the encoded ID.
   9  *    This means that framebuffers should pass it as
  10  *    DIO_ENCODE_ID(DIO_ID_FBUFFER,DIO_ID2_TOPCAT)
  11  *    (or whatever); everybody else just uses DIO_ID_FOOBAR.
  12  * void *dio_scodetoviraddr(int scode)
  13  *    Return the virtual address corresponding to the given select code.
  14  *    NB: DIO-II devices will have to be mapped in in this routine!
  15  * int dio_scodetoipl(int scode)
  16  *    Every DIO card has a fixed interrupt priority level. This function
  17  *    returns it, whatever it is.
  18  * const char *dio_scodetoname(int scode)
  19  *    Return a character string describing this board [might be "" if
  20  *    not CONFIG_DIO_CONSTANTS]
  21  * void dio_config_board(int scode)     mark board as configured in the list
  22  * void dio_unconfig_board(int scode)   mark board as no longer configured
  23  *
  24  * This file is based on the way the Amiga port handles Zorro II cards,
  25  * although we aren't so complicated...
  26  */
  27 #include <linux/config.h>
  28 #include <linux/kernel.h>
  29 #include <linux/types.h>
  30 #include <linux/dio.h>
  31 #include <linux/malloc.h>                         /* kmalloc() */
  32 #include <linux/init.h>
  33 #include <asm/hwtest.h>                           /* hwreg_present() */
  34 #include <asm/io.h>                               /* readb() */
  35 /* not a real config option yet! */
  36 #define CONFIG_DIO_CONSTANTS
  37
  38 #ifdef CONFIG_DIO_CONSTANTS
  39 /* We associate each numeric ID with an appropriate descriptive string
  40  * using a constant array of these structs.
  41  * FIXME: we should be able to arrange to throw away most of the strings
  42  * using the initdata stuff. Then we wouldn't need to worry about
  43  * carrying them around...
  44  * I think we do this by copying them into newly kmalloc()ed memory and
  45  * marking the names[] array as .initdata ?
  46  */
  47 struct dioname
  48 {
  49         int id;
  50         const char *name;
  51 };
  52
  53 /* useful macro */
  54 #define DIONAME(x) { DIO_ID_##x, DIO_DESC_##x }
  55 #define DIOFBNAME(x) { DIO_ENCODE_ID( DIO_ID_FBUFFER, DIO_ID2_##x), DIO_DESC2_##x }
  56
  57 static struct dioname names[] =
  58 {
  59         DIONAME(DCA0), DIONAME(DCA0REM), DIONAME(DCA1), DIONAME(DCA1REM),
  60         DIONAME(DCM), DIONAME(DCMREM),
  61         DIONAME(LAN),
  62         DIONAME(FHPIB), DIONAME(NHPIB), DIONAME(IHPIB),
  63         DIONAME(SCSI0), DIONAME(SCSI1), DIONAME(SCSI2), DIONAME(SCSI3),
  64         DIONAME(FBUFFER),
  65         DIONAME(PARALLEL), DIONAME(VME), DIONAME(DCL), DIONAME(DCLREM),
  66         DIONAME(MISC0), DIONAME(MISC1), DIONAME(MISC2), DIONAME(MISC3),
  67         DIONAME(MISC4), DIONAME(MISC5), DIONAME(MISC6), DIONAME(MISC7),
  68         DIONAME(MISC8), DIONAME(MISC9), DIONAME(MISC10), DIONAME(MISC11),
  69         DIONAME(MISC12), DIONAME(MISC13),
  70         DIOFBNAME(GATORBOX), DIOFBNAME(TOPCAT), DIOFBNAME(RENAISSANCE),
  71         DIOFBNAME(LRCATSEYE), DIOFBNAME(HRCCATSEYE), DIOFBNAME(HRMCATSEYE),
  72         DIOFBNAME(DAVINCI), DIOFBNAME(XXXCATSEYE), DIOFBNAME(HYPERION),
  73         DIOFBNAME(XGENESIS), DIOFBNAME(TIGER), DIOFBNAME(YGENESIS)
  74 };
  75
  76 #undef DIONAME
  77 #undef DIOFBNAME
  78
  79 #define NUMNAMES (sizeof(names) / sizeof(struct dioname))
  80
  81 static const char *unknowndioname
  82         = "unknown DIO board -- please email <pmaydell@chiark.greenend.org.uk>!";
  83
  84 static const char *dio_getname(int id)
  85 {
  86         /* return pointer to a constant string describing the board with given ID */
  87         unsigned int i;
  88         for (i = 0; i < NUMNAMES; i++)
  89                 if (names[i].id == id)
  90                         return names[i].name;
  91
  92         return unknowndioname;
  93 }
  94
  95 #else
  96
  97 static char dio_no_name[] = { 0 };
  98 #define dio_getname(_id)        (dio_no_name)
  99
 100 #endif /* CONFIG_DIO_CONSTANTS */
 101
 102 /* We represent all the DIO boards in the system with a linked list of these structs. */
 103 struct dioboard
 104 {
 105         struct dioboard *next;                    /* link to next struct in list */
 106         int ipl;                                  /* IPL of this board */
 107         int configured;                           /* has this board been configured? */
 108         int scode;                                /* select code of this board */
 109         int id;                                   /* encoded ID */
 110         const char *name;
 111 };
 112
 113 static struct dioboard *blist = NULL;
 114
 115 __initfunc(static int dio_find_slow(int deviceid))
 116 {
 117         /* Called to find a DIO device before the full bus scan has run.  Basically
 118            only used by the console driver.  */
 119         int scode;
 120         for (scode = 0; scode < DIO_SCMAX; scode++)
 121         {
 122                 void *va;
 123
 124                 if (DIO_SCINHOLE(scode))
 125                         continue;
 126
 127                 va = dio_scodetoviraddr(scode);
 128                 if (!va || !hwreg_present(va + DIO_IDOFF))
 129                         continue;             /* no board present at that select code */
 130
 131                 if (DIO_ID(va) == deviceid)
 132                         return scode;
 133         }
 134         return 0;
 135 }
 136
 137 int dio_find(int deviceid)
 138 {
 139         if (blist)
 140         {
 141                 /* fast way */
 142                 struct dioboard *b;
 143                 for (b = blist; b; b = b->next)
 144                         if (b->id == deviceid && b->configured == 0)
 145                                 return b->scode;
 146                 return 0;
 147         }
 148         return dio_find_slow(deviceid);
 149 }
 150
 151 /* This is the function that scans the DIO space and works out what
 152  * hardware is actually present.
 153  */
 154 __initfunc(void dio_init(void))
 155 {
 156         int scode;
 157         struct dioboard *b, *bprev = NULL;
 158
 159         printk("Scanning for DIO devices...\n");
 160
 161         for (scode = 0; scode < DIO_SCMAX; ++scode)
 162         {
 163                 u_char prid, secid = 0;        /* primary, secondary ID bytes */
 164                 u_char *va;
 165
 166                 if (DIO_SCINHOLE(scode))
 167                         continue;
 168
 169                 va = dio_scodetoviraddr(scode);
 170                 if (!va || !hwreg_present(va + DIO_IDOFF))
 171                         continue;              /* no board present at that select code */
 172
 173                 /* Found a board, allocate it an entry in the list */
 174                 b = kmalloc(sizeof(struct dioboard), GFP_KERNEL);
 175
 176                 /* read the ID byte(s) and encode if necessary. Note workaround
 177                  * for broken internal HPIB devices...
 178                  */
 179                 if (!DIO_ISIHPIB(scode))
 180                         prid = DIO_ID(va);
 181                 else
 182                         prid = DIO_ID_IHPIB;
 183
 184                 if (DIO_NEEDSSECID(prid))
 185                 {
 186                         secid = DIO_SECID(va);
 187                         b->id = DIO_ENCODE_ID(prid, secid);
 188                 }
 189                 else
 190                         b->id = prid;
 191
 192                 b->configured = 0;
 193                 b->scode = scode;
 194                 b->ipl = DIO_IPL(va);
 195                 b->name = dio_getname(b->id);
 196                 printk("select code %3d: ID %02X", scode, prid);
 197                 if (DIO_NEEDSSECID(b->id))
 198                         printk(":%02X", secid);
 199                 printk(" %s\n", b->name);
 200
 201                 b->next = NULL;
 202
 203                 if (bprev)
 204                         bprev->next = b;
 205                 else
 206                         blist = b;
 207                 bprev = b;
 208         }
 209 }
 210
 211 /* Bear in mind that this is called in the very early stages of initialisation
 212  * in order to get the virtual address of the serial port for the console...
 213  */
 214 void *dio_scodetoviraddr(int scode)
 215 {
 216         if (scode > DIOII_SCBASE)
 217         {
 218                 printk("dio_scodetoviraddr: don't support DIO-II yet!\n");
 219                 return 0;
 220         }
 221         else if (scode > DIO_SCMAX || scode < 0)
 222                 return 0;
 223         else if (DIO_SCINHOLE(scode))
 224                 return 0;
 225         else if (scode == DIO_IHPIBSCODE) /* this should really be #ifdef CONFIG_IHPIB */
 226                 return (void*)DIO_IHPIBADDR;   /* or something similar... */
 227
 228         return (void*)(DIO_VIRADDRBASE + DIO_BASE + scode * 0x10000);
 229 }
 230
 231 int dio_scodetoipl(int scode)
 232 {
 233         struct dioboard *b;
 234         for (b = blist; b; b = b->next)
 235                 if (b->scode == scode)
 236                         break;
 237
 238         if (!b)
 239         {
 240                 printk("dio_scodetoipl: bad select code %d\n", scode);
 241                 return 0;
 242         }
 243         else
 244                 return b->ipl;
 245 }
 246
 247 const char *dio_scodetoname(int scode)
 248 {
 249         struct dioboard *b;
 250         for (b = blist; b; b = b->next)
 251                 if (b->scode == scode)
 252                         break;
 253
 254         if (!b)
 255         {
 256                 printk("dio_scodetoname: bad select code %d\n", scode);
 257                 return NULL;
 258         }
 259         else
 260                 return b->name;
 261 }
 262
 263 void dio_config_board(int scode)
 264 {
 265         struct dioboard *b;
 266         for (b = blist; b; b = b->next)
 267                 if (b->scode == scode)
 268                         break;
 269
 270         if (!b)
 271                 printk("dio_config_board: bad select code %d\n", scode);
 272         else if (b->configured)
 273                 printk("dio_config_board: board at select code %d already configured\n", scode);
 274         else
 275                 b->configured = 1;
 276 }
 277
 278 void dio_unconfig_board(int scode)
 279 {
 280         struct dioboard *b;
 281         for (b = blist; b; b = b->next)
 282                 if (b->scode == scode)
 283                         break;
 284
 285         if (!b)
 286                 printk("dio_unconfig_board: bad select code %d\n", scode);
 287         else if (!b->configured)
 288                 printk("dio_unconfig_board: board at select code %d not configured\n",
 289                        scode);
 290         else
 291                 b->configured = 0;
 292 }