sys/isa/pnp.c

   1 /*
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1996, Sujal M. Patel
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  *      from: pnp.c,v 1.11 1999/05/06 22:11:19 peter Exp
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/kernel.h>
  37 #include <sys/module.h>
  38 #include <sys/bus.h>
  39 #include <sys/endian.h>
  40 #include <sys/malloc.h>
  41 #include <isa/isavar.h>
  42 #include <isa/pnpreg.h>
  43 #include <isa/pnpvar.h>
  44 #include <machine/bus.h>
  45
  46 typedef struct _pnp_id {
  47         uint32_t vendor_id;
  48         uint32_t serial;
  49         u_char checksum;
  50 } pnp_id;
  51
  52 struct pnp_set_config_arg {
  53         int     csn;            /* Card number to configure */
  54         int     ldn;            /* Logical device on card */
  55 };
  56
  57 struct pnp_quirk {
  58         uint32_t vendor_id;     /* Vendor of the card */
  59         uint32_t logical_id;    /* ID of the device with quirk */
  60         int     type;
  61 #define PNP_QUIRK_WRITE_REG     1 /* Need to write a pnp register  */
  62 #define PNP_QUIRK_EXTRA_IO      2 /* Has extra io ports  */
  63         int     arg1;
  64         int     arg2;
  65 };
  66
  67 struct pnp_quirk pnp_quirks[] = {
  68         /*
  69          * The Gravis UltraSound needs register 0xf2 to be set to 0xff
  70          * to enable power.
  71          * XXX need to know the logical device id.
  72          */
  73         { 0x0100561e /* GRV0001 */,     0,
  74           PNP_QUIRK_WRITE_REG,  0xf2,    0xff },
  75         /*
  76          * An emu8000 does not give us other than the first
  77          * port.
  78          */
  79         { 0x26008c0e /* SB16 */,        0x21008c0e,
  80           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  81         { 0x42008c0e /* SB32(CTL0042) */,       0x21008c0e,
  82           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  83         { 0x44008c0e /* SB32(CTL0044) */,       0x21008c0e,
  84           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  85         { 0x49008c0e /* SB32(CTL0049) */,       0x21008c0e,
  86           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  87         { 0xf1008c0e /* SB32(CTL00f1) */,       0x21008c0e,
  88           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  89         { 0xc1008c0e /* SB64(CTL00c1) */,       0x22008c0e,
  90           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  91         { 0xc5008c0e /* SB64(CTL00c5) */,       0x22008c0e,
  92           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  93         { 0xe4008c0e /* SB64(CTL00e4) */,       0x22008c0e,
  94           PNP_QUIRK_EXTRA_IO,   0x400,   0x800 },
  95
  96         { 0 }
  97 };
  98
  99 /* The READ_DATA port that we are using currently */
 100 static int pnp_rd_port;
 101
 102 static void   pnp_send_initiation_key(void);
 103 static int    pnp_get_serial(pnp_id *p);
 104 static int    pnp_isolation_protocol(device_t parent);
 105
 106 char *
 107 pnp_eisaformat(uint32_t id)
 108 {
 109         uint8_t *data;
 110         static char idbuf[8];
 111         const char  hextoascii[] = "0123456789abcdef";
 112
 113         id = htole32(id);
 114         data = (uint8_t *)&id;
 115         idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
 116         idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
 117         idbuf[2] = '@' + (data[1] & 0x1f);
 118         idbuf[3] = hextoascii[(data[2] >> 4)];
 119         idbuf[4] = hextoascii[(data[2] & 0xf)];
 120         idbuf[5] = hextoascii[(data[3] >> 4)];
 121         idbuf[6] = hextoascii[(data[3] & 0xf)];
 122         idbuf[7] = 0;
 123         return(idbuf);
 124 }
 125
 126 static void
 127 pnp_write(int d, u_char r)
 128 {
 129         outb (_PNP_ADDRESS, d);
 130         outb (_PNP_WRITE_DATA, r);
 131 }
 132
 133 /*
 134  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
 135  * Intel May 94.
 136  */
 137 static void
 138 pnp_send_initiation_key()
 139 {
 140         int cur, i;
 141
 142         /* Reset the LSFR */
 143         outb(_PNP_ADDRESS, 0);
 144         outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
 145
 146         cur = 0x6a;
 147         outb(_PNP_ADDRESS, cur);
 148
 149         for (i = 1; i < 32; i++) {
 150                 cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
 151                 outb(_PNP_ADDRESS, cur);
 152         }
 153 }
 154
 155
 156 /*
 157  * Get the device's serial number.  Returns 1 if the serial is valid.
 158  */
 159 static int
 160 pnp_get_serial(pnp_id *p)
 161 {
 162         int i, bit, valid = 0, sum = 0x6a;
 163         u_char *data = (u_char *)p;
 164
 165         bzero(data, sizeof(char) * 9);
 166         outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
 167         for (i = 0; i < 72; i++) {
 168                 bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
 169                 DELAY(250);     /* Delay 250 usec */
 170
 171                 /* Can't Short Circuit the next evaluation, so 'and' is last */
 172                 bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
 173                 DELAY(250);     /* Delay 250 usec */
 174
 175                 valid = valid || bit;
 176                 if (i < 64)
 177                         sum = (sum >> 1) |
 178                           (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
 179                 data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
 180         }
 181
 182         valid = valid && (data[8] == sum);
 183
 184         return (valid);
 185 }
 186
 187 /*
 188  * Fill's the buffer with resource info from the device.
 189  * Returns the number of characters read.
 190  */
 191 static int
 192 pnp_get_resource_info(u_char *buffer, int len)
 193 {
 194         int i, j, count;
 195         u_char temp;
 196
 197         count = 0;
 198         for (i = 0; i < len; i++) {
 199                 outb(_PNP_ADDRESS, PNP_STATUS);
 200                 for (j = 0; j < 100; j++) {
 201                         if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
 202                                 break;
 203                         DELAY(10);
 204                 }
 205                 if (j == 100) {
 206                         printf("PnP device failed to report resource data\n");
 207                         return (count);
 208                 }
 209                 outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
 210                 temp = inb((pnp_rd_port << 2) | 0x3);
 211                 if (buffer != NULL)
 212                         buffer[i] = temp;
 213                 count++;
 214         }
 215         return (count);
 216 }
 217
 218 /*
 219  * This function is called after the bus has assigned resource
 220  * locations for a logical device.
 221  */
 222 static void
 223 pnp_set_config(void *arg, struct isa_config *config, int enable)
 224 {
 225         int csn = ((struct pnp_set_config_arg *) arg)->csn;
 226         int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
 227         int i;
 228
 229         /*
 230          * First put all cards into Sleep state with the initiation
 231          * key, then put our card into Config state.
 232          */
 233         pnp_send_initiation_key();
 234         pnp_write(PNP_WAKE, csn);
 235
 236         /*
 237          * Select our logical device so that we can program it.
 238          */
 239         pnp_write(PNP_SET_LDN, ldn);
 240
 241         /*
 242          * Constrain the number of resources we will try to program
 243          */
 244         if (config->ic_nmem > ISA_PNP_NMEM) {
 245                 printf("too many ISA memory ranges (%d > %d)\n",
 246                     config->ic_nmem, ISA_PNP_NMEM);
 247                 config->ic_nmem = ISA_PNP_NMEM;
 248         }
 249         if (config->ic_nport > ISA_PNP_NPORT) {
 250                 printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
 251                     ISA_PNP_NPORT);
 252                 config->ic_nport = ISA_PNP_NPORT;
 253         }
 254         if (config->ic_nirq > ISA_PNP_NIRQ) {
 255                 printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
 256                     ISA_PNP_NIRQ);
 257                 config->ic_nirq = ISA_PNP_NIRQ;
 258         }
 259         if (config->ic_ndrq > ISA_PNP_NDRQ) {
 260                 printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
 261                     ISA_PNP_NDRQ);
 262                 config->ic_ndrq = ISA_PNP_NDRQ;
 263         }
 264
 265         /*
 266          * Now program the resources.
 267          */
 268         for (i = 0; i < config->ic_nmem; i++) {
 269                 uint32_t start;
 270                 uint32_t size;
 271
 272                 /* XXX: should handle memory control register, 32 bit memory */
 273                 if (config->ic_mem[i].ir_size == 0) {
 274                         pnp_write(PNP_MEM_BASE_HIGH(i), 0);
 275                         pnp_write(PNP_MEM_BASE_LOW(i), 0);
 276                         pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
 277                         pnp_write(PNP_MEM_RANGE_LOW(i), 0);
 278                 } else {
 279                         start = config->ic_mem[i].ir_start;
 280                         size =  config->ic_mem[i].ir_size;
 281                         if (start & 0xff)
 282                                 panic("pnp_set_config: bogus memory assignment");
 283                         pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
 284                         pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
 285                         pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
 286                         pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
 287                 }
 288         }
 289         for (; i < ISA_PNP_NMEM; i++) {
 290                 pnp_write(PNP_MEM_BASE_HIGH(i), 0);
 291                 pnp_write(PNP_MEM_BASE_LOW(i), 0);
 292                 pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
 293                 pnp_write(PNP_MEM_RANGE_LOW(i), 0);
 294         }
 295
 296         for (i = 0; i < config->ic_nport; i++) {
 297                 uint32_t start;
 298
 299                 if (config->ic_port[i].ir_size == 0) {
 300                         pnp_write(PNP_IO_BASE_HIGH(i), 0);
 301                         pnp_write(PNP_IO_BASE_LOW(i), 0);
 302                 } else {
 303                         start = config->ic_port[i].ir_start;
 304                         pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
 305                         pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
 306                 }
 307         }
 308         for (; i < ISA_PNP_NPORT; i++) {
 309                 pnp_write(PNP_IO_BASE_HIGH(i), 0);
 310                 pnp_write(PNP_IO_BASE_LOW(i), 0);
 311         }
 312
 313         for (i = 0; i < config->ic_nirq; i++) {
 314                 int irq;
 315
 316                 /* XXX: interrupt type */
 317                 if (config->ic_irqmask[i] == 0) {
 318                         pnp_write(PNP_IRQ_LEVEL(i), 0);
 319                         pnp_write(PNP_IRQ_TYPE(i), 2);
 320                 } else {
 321                         irq = ffs(config->ic_irqmask[i]) - 1;
 322                         pnp_write(PNP_IRQ_LEVEL(i), irq);
 323                         pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
 324                 }
 325         }
 326         for (; i < ISA_PNP_NIRQ; i++) {
 327                 /*
 328                  * IRQ 0 is not a valid interrupt selection and
 329                  * represents no interrupt selection.
 330                  */
 331                 pnp_write(PNP_IRQ_LEVEL(i), 0);
 332                 pnp_write(PNP_IRQ_TYPE(i), 2);
 333         }
 334
 335         for (i = 0; i < config->ic_ndrq; i++) {
 336                 int drq;
 337
 338                 if (config->ic_drqmask[i] == 0) {
 339                         pnp_write(PNP_DMA_CHANNEL(i), 4);
 340                 } else {
 341                         drq = ffs(config->ic_drqmask[i]) - 1;
 342                         pnp_write(PNP_DMA_CHANNEL(i), drq);
 343                 }
 344         }
 345         for (; i < ISA_PNP_NDRQ; i++) {
 346                 /*
 347                  * DMA channel 4, the cascade channel is used to
 348                  * indicate no DMA channel is active.
 349                  */
 350                 pnp_write(PNP_DMA_CHANNEL(i), 4);
 351         }
 352
 353         pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
 354
 355         /*
 356          * Wake everyone up again, we are finished.
 357          */
 358         pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
 359 }
 360
 361 /*
 362  * Process quirks for a logical device.. The card must be in Config state.
 363  */
 364 void
 365 pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
 366     struct isa_config *config)
 367 {
 368         struct pnp_quirk *qp;
 369
 370         for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
 371                 if (qp->vendor_id == vendor_id
 372                     && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
 373                         switch (qp->type) {
 374                         case PNP_QUIRK_WRITE_REG:
 375                                 pnp_write(PNP_SET_LDN, ldn);
 376                                 pnp_write(qp->arg1, qp->arg2);
 377                                 break;
 378                         case PNP_QUIRK_EXTRA_IO:
 379                                 if (config == NULL)
 380                                         break;
 381                                 if (qp->arg1 != 0) {
 382                                         config->ic_nport++;
 383                                         config->ic_port[config->ic_nport - 1] = config->ic_port[0];
 384                                         config->ic_port[config->ic_nport - 1].ir_start += qp->arg1;
 385                                         config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
 386                                 }
 387                                 if (qp->arg2 != 0) {
 388                                         config->ic_nport++;
 389                                         config->ic_port[config->ic_nport - 1] = config->ic_port[0];
 390                                         config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
 391                                         config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
 392                                 }
 393                                 break;
 394                         }
 395                 }
 396         }
 397 }
 398
 399 /*
 400  * Scan Resource Data for Logical Devices.
 401  *
 402  * This function exits as soon as it gets an error reading *ANY*
 403  * Resource Data or it reaches the end of Resource Data.  In the first
 404  * case the return value will be TRUE, FALSE otherwise.
 405  */
 406 static int
 407 pnp_create_devices(device_t parent, pnp_id *p, int csn,
 408     u_char *resources, int len)
 409 {
 410         u_char tag, *resp, *resinfo, *startres = NULL;
 411         int large_len, scanning = len, retval = FALSE;
 412         uint32_t logical_id;
 413         device_t dev = 0;
 414         int ldn = 0;
 415         struct pnp_set_config_arg *csnldn;
 416         char buf[100];
 417         char *desc = NULL;
 418
 419         resp = resources;
 420         while (scanning > 0) {
 421                 tag = *resp++;
 422                 scanning--;
 423                 if (PNP_RES_TYPE(tag) != 0) {
 424                         /* Large resource */
 425                         if (scanning < 2) {
 426                                 scanning = 0;
 427                                 continue;
 428                         }
 429                         large_len = resp[0] + (resp[1] << 8);
 430                         resp += 2;
 431
 432                         if (scanning < large_len) {
 433                                 scanning = 0;
 434                                 continue;
 435                         }
 436                         resinfo = resp;
 437                         resp += large_len;
 438                         scanning -= large_len;
 439
 440                         if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
 441                                 if (dev) {
 442                                         /*
 443                                          * This is an optional device
 444                                          * identifier string. Skip it
 445                                          * for now.
 446                                          */
 447                                         continue;
 448                                 }
 449                                 /* else mandately card identifier string */
 450                                 if (large_len > sizeof(buf) - 1)
 451                                         large_len = sizeof(buf) - 1;
 452                                 bcopy(resinfo, buf, large_len);
 453
 454                                 /*
 455                                  * Trim trailing spaces.
 456                                  */
 457                                 while (buf[large_len-1] == ' ')
 458                                         large_len--;
 459                                 buf[large_len] = '\0';
 460                                 desc = buf;
 461                                 continue;
 462                         }
 463
 464                         continue;
 465                 }
 466
 467                 /* Small resource */
 468                 if (scanning < PNP_SRES_LEN(tag)) {
 469                         scanning = 0;
 470                         continue;
 471                 }
 472                 resinfo = resp;
 473                 resp += PNP_SRES_LEN(tag);
 474                 scanning -= PNP_SRES_LEN(tag);
 475
 476                 switch (PNP_SRES_NUM(tag)) {
 477                 case PNP_TAG_LOGICAL_DEVICE:
 478                         /*
 479                          * Parse the resources for the previous
 480                          * logical device (if any).
 481                          */
 482                         if (startres) {
 483                                 pnp_parse_resources(dev, startres,
 484                                     resinfo - startres - 1, ldn);
 485                                 dev = 0;
 486                                 startres = NULL;
 487                         }
 488
 489                         /*
 490                          * A new logical device. Scan for end of
 491                          * resources.
 492                          */
 493                         bcopy(resinfo, &logical_id, 4);
 494                         pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
 495                         dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
 496                         if (desc)
 497                                 device_set_desc_copy(dev, desc);
 498                         else
 499                                 device_set_desc_copy(dev,
 500                                     pnp_eisaformat(logical_id));
 501                         isa_set_vendorid(dev, p->vendor_id);
 502                         isa_set_serial(dev, p->serial);
 503                         isa_set_logicalid(dev, logical_id);
 504                         isa_set_configattr(dev,
 505                             ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
 506                         csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
 507                         if (!csnldn) {
 508                                 device_printf(parent, "out of memory\n");
 509                                 scanning = 0;
 510                                 break;
 511                         }
 512                         csnldn->csn = csn;
 513                         csnldn->ldn = ldn;
 514                         ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
 515                             csnldn);
 516                         isa_set_pnp_csn(dev, csn);
 517                         isa_set_pnp_ldn(dev, ldn);
 518                         ldn++;
 519                         startres = resp;
 520                         break;
 521
 522                 case PNP_TAG_END:
 523                         if (!startres) {
 524                                 device_printf(parent, "malformed resources\n");
 525                                 scanning = 0;
 526                                 break;
 527                         }
 528                         pnp_parse_resources(dev, startres,
 529                             resinfo - startres - 1, ldn);
 530                         dev = 0;
 531                         startres = NULL;
 532                         scanning = 0;
 533                         break;
 534
 535                 default:
 536                         /* Skip this resource */
 537                         break;
 538                 }
 539         }
 540
 541         return (retval);
 542 }
 543
 544 /*
 545  * Read 'amount' bytes of resources from the card, allocating memory
 546  * as needed. If a buffer is already available, it should be passed in
 547  * '*resourcesp' and its length in '*spacep'. The number of resource
 548  * bytes already in the buffer should be passed in '*lenp'. The memory
 549  * allocated will be returned in '*resourcesp' with its size and the
 550  * number of bytes of resources in '*spacep' and '*lenp' respectively.
 551  *
 552  * XXX: Multiple problems here, we forget to free() stuff in one
 553  * XXX: error return, and in another case we free (*resourcesp) but
 554  * XXX: don't tell the caller.
 555  */
 556 static int
 557 pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
 558 {
 559         u_char *resources = *resourcesp;
 560         u_char *newres;
 561         int space = *spacep;
 562         int len = *lenp;
 563
 564         if (space == 0) {
 565                 space = 1024;
 566                 resources = malloc(space, M_TEMP, M_NOWAIT);
 567                 if (!resources)
 568                         return (ENOMEM);
 569         }
 570
 571         if (len + amount > space) {
 572                 int extra = 1024;
 573                 while (len + amount > space + extra)
 574                         extra += 1024;
 575                 newres = malloc(space + extra, M_TEMP, M_NOWAIT);
 576                 if (!newres) {
 577                         /* XXX: free resources */
 578                         return (ENOMEM);
 579                 }
 580                 bcopy(resources, newres, len);
 581                 free(resources, M_TEMP);
 582                 resources = newres;
 583                 space += extra;
 584         }
 585
 586         if (pnp_get_resource_info(resources + len, amount) != amount)
 587                 return (EINVAL);
 588         len += amount;
 589
 590         *resourcesp = resources;
 591         *spacep = space;
 592         *lenp = len;
 593
 594         return (0);
 595 }
 596
 597 /*
 598  * Read all resources from the card, allocating memory as needed. If a
 599  * buffer is already available, it should be passed in '*resourcesp'
 600  * and its length in '*spacep'. The memory allocated will be returned
 601  * in '*resourcesp' with its size and the number of bytes of resources
 602  * in '*spacep' and '*lenp' respectively.
 603  */
 604 static int
 605 pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
 606 {
 607         u_char *resources = *resourcesp;
 608         int space = *spacep;
 609         int len = 0;
 610         int error, done;
 611         u_char tag;
 612
 613         error = 0;
 614         done = 0;
 615         while (!done) {
 616                 error = pnp_read_bytes(1, &resources, &space, &len);
 617                 if (error)
 618                         goto out;
 619                 tag = resources[len-1];
 620                 if (PNP_RES_TYPE(tag) == 0) {
 621                         /*
 622                          * Small resource, read contents.
 623                          */
 624                         error = pnp_read_bytes(PNP_SRES_LEN(tag),
 625                             &resources, &space, &len);
 626                         if (error)
 627                                 goto out;
 628                         if (PNP_SRES_NUM(tag) == PNP_TAG_END)
 629                                 done = 1;
 630                 } else {
 631                         /*
 632                          * Large resource, read length and contents.
 633                          */
 634                         error = pnp_read_bytes(2, &resources, &space, &len);
 635                         if (error)
 636                                 goto out;
 637                         error = pnp_read_bytes(resources[len-2]
 638                             + (resources[len-1] << 8), &resources, &space,
 639                             &len);
 640                         if (error)
 641                                 goto out;
 642                 }
 643         }
 644
 645  out:
 646         *resourcesp = resources;
 647         *spacep = space;
 648         *lenp = len;
 649         return (error);
 650 }
 651
 652 /*
 653  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
 654  * value (caller should try multiple READ_DATA locations before giving
 655  * up). Upon exiting, all cards are aware that they should use
 656  * pnp_rd_port as the READ_DATA port.
 657  *
 658  * In the first pass, a csn is assigned to each board and pnp_id's
 659  * are saved to an array, pnp_devices. In the second pass, each
 660  * card is woken up and the device configuration is called.
 661  */
 662 static int
 663 pnp_isolation_protocol(device_t parent)
 664 {
 665         int csn;
 666         pnp_id id;
 667         int found = 0, len;
 668         u_char *resources = NULL;
 669         int space = 0;
 670         int error;
 671
 672         /*
 673          * Put all cards into the Sleep state so that we can clear
 674          * their CSNs.
 675          */
 676         pnp_send_initiation_key();
 677
 678         /*
 679          * Clear the CSN for all cards.
 680          */
 681         pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
 682
 683         /*
 684          * Move all cards to the Isolation state.
 685          */
 686         pnp_write(PNP_WAKE, 0);
 687
 688         /*
 689          * Tell them where the read point is going to be this time.
 690          */
 691         pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
 692
 693         for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
 694                 /*
 695                  * Start the serial isolation protocol.
 696                  */
 697                 outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
 698                 DELAY(1000);    /* Delay 1 msec */
 699
 700                 if (pnp_get_serial(&id)) {
 701                         /*
 702                          * We have read the id from a card
 703                          * successfully. The card which won the
 704                          * isolation protocol will be in Isolation
 705                          * mode and all others will be in Sleep.
 706                          * Program the CSN of the isolated card
 707                          * (taking it to Config state) and read its
 708                          * resources, creating devices as we find
 709                          * logical devices on the card.
 710                          */
 711                         pnp_write(PNP_SET_CSN, csn);
 712                         if (bootverbose)
 713                                 printf("Reading PnP configuration for %s.\n",
 714                                     pnp_eisaformat(id.vendor_id));
 715                         error = pnp_read_resources(&resources, &space, &len);
 716                         if (error)
 717                                 break;
 718                         pnp_create_devices(parent, &id, csn, resources, len);
 719                         found++;
 720                 } else
 721                         break;
 722
 723                 /*
 724                  * Put this card back to the Sleep state and
 725                  * simultaneously move all cards which don't have a
 726                  * CSN yet to Isolation state.
 727                  */
 728                 pnp_write(PNP_WAKE, 0);
 729         }
 730
 731         /*
 732          * Unless we have chosen the wrong read port, all cards will
 733          * be in Sleep state. Put them back into WaitForKey for
 734          * now. Their resources will be programmed later.
 735          */
 736         pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
 737
 738         /*
 739          * Cleanup.
 740          */
 741         if (resources)
 742                 free(resources, M_TEMP);
 743
 744         return (found);
 745 }
 746
 747
 748 /*
 749  * pnp_identify()
 750  *
 751  * autoconfiguration of pnp devices. This routine just runs the
 752  * isolation protocol over several ports, until one is successful.
 753  *
 754  * may be called more than once ?
 755  *
 756  */
 757
 758 static void
 759 pnp_identify(driver_t *driver, device_t parent)
 760 {
 761         int num_pnp_devs;
 762
 763         /* Try various READ_DATA ports from 0x203-0x3ff */
 764         for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
 765                 if (bootverbose)
 766                         printf("pnp_identify: Trying Read_Port at %x\n",
 767                             (pnp_rd_port << 2) | 0x3);
 768
 769                 num_pnp_devs = pnp_isolation_protocol(parent);
 770                 if (num_pnp_devs)
 771                         break;
 772         }
 773         if (bootverbose)
 774                 printf("PNP Identify complete\n");
 775 }
 776
 777 static device_method_t pnp_methods[] = {
 778         /* Device interface */
 779         DEVMETHOD(device_identify,      pnp_identify),
 780
 781         { 0, 0 }
 782 };
 783
 784 static driver_t pnp_driver = {
 785         "pnp",
 786         pnp_methods,
 787         1,                      /* no softc */
 788 };
 789
 790 static devclass_t pnp_devclass;
 791
 792 DRIVER_MODULE(pnp, isa, pnp_driver, pnp_devclass, 0, 0);