xref: /freebsd/sys/isa/pnp.c (revision f9ce010afdd3136fc73e2b500f2ed916bf9cfa59)
1 /*
2  * Copyright (c) 1996, Sujal M. Patel
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	$FreeBSD$
27  *      from: pnp.c,v 1.11 1999/05/06 22:11:19 peter Exp
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/bus.h>
35 #include <sys/malloc.h>
36 #include <isa/isavar.h>
37 #include <isa/pnpreg.h>
38 #include <isa/pnpvar.h>
39 #include <machine/resource.h>
40 #include <machine/clock.h>
41 
42 typedef struct _pnp_id {
43 	u_int32_t vendor_id;
44 	u_int32_t serial;
45 	u_char checksum;
46 } pnp_id;
47 
48 struct pnp_set_config_arg {
49 	int	csn;		/* Card number to configure */
50 	int	ldn;		/* Logical device on card */
51 };
52 
53 struct pnp_quirk {
54 	u_int32_t vendor_id;	/* Vendor of the card */
55 	u_int32_t logical_id;	/* ID of the device with quirk */
56 	int	type;
57 #define PNP_QUIRK_WRITE_REG	1 /* Need to write a pnp register  */
58 	int	arg1;
59 	int	arg2;
60 };
61 
62 struct pnp_quirk pnp_quirks[] = {
63 	/*
64 	 * The Gravis UltraSound needs register 0xf2 to be set to 0xff
65 	 * to enable power.
66 	 * XXX need to know the logical device id.
67 	 */
68 	{ 0x0100561e /* GRV0001 */,	0,
69 	  PNP_QUIRK_WRITE_REG,	0xf2,	 0xff },
70 
71 	{ 0 }
72 };
73 
74 #if 0
75 /*
76  * these entries are initialized using the autoconfig menu
77  * The struct is invalid (and must be initialized) if the first
78  * CSN is zero. The init code fills invalid entries with CSN 255
79  * which is not a supported value.
80  */
81 
82 struct pnp_cinfo pnp_ldn_overrides[MAX_PNP_LDN] = {
83     { 0 }
84 };
85 #endif
86 
87 /* The READ_DATA port that we are using currently */
88 static int pnp_rd_port;
89 
90 static void   pnp_send_initiation_key(void);
91 static int    pnp_get_serial(pnp_id *p);
92 static int    pnp_isolation_protocol(device_t parent);
93 
94 static void
95 pnp_write(int d, u_char r)
96 {
97 	outb (_PNP_ADDRESS, d);
98 	outb (_PNP_WRITE_DATA, r);
99 }
100 
101 #if 0
102 
103 static u_char
104 pnp_read(int d)
105 {
106 	outb (_PNP_ADDRESS, d);
107 	return (inb(3 | (pnp_rd_port <<2)));
108 }
109 
110 #endif
111 
112 /*
113  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
114  * Intel May 94.
115  */
116 static void
117 pnp_send_initiation_key()
118 {
119 	int cur, i;
120 
121 	/* Reset the LSFR */
122 	outb(_PNP_ADDRESS, 0);
123 	outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
124 
125 	cur = 0x6a;
126 	outb(_PNP_ADDRESS, cur);
127 
128 	for (i = 1; i < 32; i++) {
129 		cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
130 		outb(_PNP_ADDRESS, cur);
131 	}
132 }
133 
134 
135 /*
136  * Get the device's serial number.  Returns 1 if the serial is valid.
137  */
138 static int
139 pnp_get_serial(pnp_id *p)
140 {
141 	int i, bit, valid = 0, sum = 0x6a;
142 	u_char *data = (u_char *)p;
143 
144 	bzero(data, sizeof(char) * 9);
145 	outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
146 	for (i = 0; i < 72; i++) {
147 		bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
148 		DELAY(250);	/* Delay 250 usec */
149 
150 		/* Can't Short Circuit the next evaluation, so 'and' is last */
151 		bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
152 		DELAY(250);	/* Delay 250 usec */
153 
154 		valid = valid || bit;
155 
156 		if (i < 64)
157 			sum = (sum >> 1) |
158 				(((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
159 
160 		data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
161 	}
162 
163 	valid = valid && (data[8] == sum);
164 
165 	return valid;
166 }
167 
168 /*
169  * Fill's the buffer with resource info from the device.
170  * Returns 0 if the device fails to report
171  */
172 static int
173 pnp_get_resource_info(u_char *buffer, int len)
174 {
175 	int i, j;
176 	u_char temp;
177 
178 	for (i = 0; i < len; i++) {
179 		outb(_PNP_ADDRESS, PNP_STATUS);
180 		for (j = 0; j < 100; j++) {
181 			if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
182 				break;
183 			DELAY(1);
184 		}
185 		if (j == 100) {
186 			printf("PnP device failed to report resource data\n");
187 			return 0;
188 		}
189 		outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
190 		temp = inb((pnp_rd_port << 2) | 0x3);
191 		if (buffer != NULL)
192 			buffer[i] = temp;
193 	}
194 	return 1;
195 }
196 
197 #if 0
198 /*
199  * write_pnp_parms initializes a logical device with the parms
200  * in d, and then activates the board if the last parameter is 1.
201  */
202 
203 static int
204 write_pnp_parms(struct pnp_cinfo *d, pnp_id *p, int ldn)
205 {
206     int i, empty = -1 ;
207 
208     pnp_write (SET_LDN, ldn );
209     i = pnp_read(SET_LDN) ;
210     if (i != ldn) {
211 	printf("Warning: LDN %d does not exist\n", ldn);
212     }
213     for (i = 0; i < 8; i++) {
214 	pnp_write(IO_CONFIG_BASE + i * 2, d->ic_port[i] >> 8 );
215 	pnp_write(IO_CONFIG_BASE + i * 2 + 1, d->ic_port[i] & 0xff );
216     }
217     for (i = 0; i < 4; i++) {
218 	pnp_write(MEM_CONFIG + i*8, (d->ic_mem[i].base >> 16) & 0xff );
219 	pnp_write(MEM_CONFIG + i*8+1, (d->ic_mem[i].base >> 8) & 0xff );
220 	pnp_write(MEM_CONFIG + i*8+2, d->ic_mem[i].control & 0xff );
221 	pnp_write(MEM_CONFIG + i*8+3, (d->ic_mem[i].range >> 16) & 0xff );
222 	pnp_write(MEM_CONFIG + i*8+4, (d->ic_mem[i].range >> 8) & 0xff );
223     }
224     for (i = 0; i < 2; i++) {
225 	pnp_write(IRQ_CONFIG + i*2    , d->irq[i] );
226 	pnp_write(IRQ_CONFIG + i*2 + 1, d->irq_type[i] );
227 	pnp_write(DRQ_CONFIG + i, d->drq[i] );
228     }
229     /*
230      * store parameters read into the current kernel
231      * so manual editing next time is easier
232      */
233     for (i = 0 ; i < MAX_PNP_LDN; i++) {
234 	if (pnp_ldn_overrides[i].csn == d->csn &&
235 		pnp_ldn_overrides[i].ldn == ldn) {
236 	    d->flags = pnp_ldn_overrides[i].flags ;
237 	    pnp_ldn_overrides[i] = *d ;
238 	    break ;
239 	} else if (pnp_ldn_overrides[i].csn < 1 ||
240 		pnp_ldn_overrides[i].csn == 255)
241 	    empty = i ;
242     }
243     if (i== MAX_PNP_LDN && empty != -1)
244 	pnp_ldn_overrides[empty] = *d;
245 
246     /*
247      * Here should really perform the range check, and
248      * return a failure if not successful.
249      */
250     pnp_write (IO_RANGE_CHECK, 0);
251     DELAY(1000); /* XXX is it really necessary ? */
252     pnp_write (ACTIVATE, d->enable ? 1 : 0);
253     DELAY(1000); /* XXX is it really necessary ? */
254     return 1 ;
255 }
256 #endif
257 
258 /*
259  * This function is called after the bus has assigned resource
260  * locations for a logical device.
261  */
262 static void
263 pnp_set_config(void *arg, struct isa_config *config, int enable)
264 {
265 	int csn = ((struct pnp_set_config_arg *) arg)->csn;
266 	int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
267 	int i;
268 
269 	/*
270 	 * First put all cards into Sleep state with the initiation
271 	 * key, then put our card into Config state.
272 	 */
273 	pnp_send_initiation_key();
274 	pnp_write(PNP_WAKE, csn);
275 
276 	/*
277 	 * Select our logical device so that we can program it.
278 	 */
279 	pnp_write(PNP_SET_LDN, ldn);
280 
281 	/*
282 	 * Now program the resources.
283 	 */
284 	for (i = 0; i < config->ic_nmem; i++) {
285 		u_int32_t start = config->ic_mem[i].ir_start;
286 		u_int32_t size =  config->ic_mem[i].ir_size;
287 		if (start & 0xff)
288 			panic("pnp_set_config: bogus memory assignment");
289 		pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
290 		pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
291 		pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
292 		pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
293 	}
294 	for (; i < ISA_NMEM; i++) {
295 		pnp_write(PNP_MEM_BASE_HIGH(i), 0);
296 		pnp_write(PNP_MEM_BASE_LOW(i), 0);
297 		pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
298 		pnp_write(PNP_MEM_RANGE_LOW(i), 0);
299 	}
300 
301 	for (i = 0; i < config->ic_nport; i++) {
302 		u_int32_t start = config->ic_port[i].ir_start;
303 		pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
304 		pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
305 	}
306 	for (; i < ISA_NPORT; i++) {
307 		pnp_write(PNP_IO_BASE_HIGH(i), 0);
308 		pnp_write(PNP_IO_BASE_LOW(i), 0);
309 	}
310 
311 	for (i = 0; i < config->ic_nirq; i++) {
312 		int irq = ffs(config->ic_irqmask[i]) - 1;
313 		pnp_write(PNP_IRQ_LEVEL(i), irq);
314 		pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
315 	}
316 	for (; i < ISA_NIRQ; i++) {
317 		/*
318 		 * IRQ 0 is not a valid interrupt selection and
319 		 * represents no interrupt selection.
320 		 */
321 		pnp_write(PNP_IRQ_LEVEL(i), 0);
322 	}
323 
324 	for (i = 0; i < config->ic_ndrq; i++) {
325 		int drq = ffs(config->ic_drqmask[i]) - 1;
326 		pnp_write(PNP_DMA_CHANNEL(i), drq);
327 	}
328 	for (; i < ISA_NDRQ; i++) {
329 		/*
330 		 * DMA channel 4, the cascade channel is used to
331 		 * indicate no DMA channel is active.
332 		 */
333 		pnp_write(PNP_DMA_CHANNEL(i), 4);
334 	}
335 
336 	pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
337 
338 	/*
339 	 * Wake everyone up again, we are finished.
340 	 */
341 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
342 }
343 
344 /*
345  * Process quirks for a logical device.. The card must be in Config state.
346  */
347 static void
348 pnp_check_quirks(u_int32_t vendor_id, u_int32_t logical_id, int ldn)
349 {
350 	struct pnp_quirk *qp;
351 
352 	for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
353 		if (qp->vendor_id == vendor_id
354 		    && (qp->logical_id == 0
355 			|| qp->logical_id == logical_id)) {
356 			switch (qp->type) {
357 			case PNP_QUIRK_WRITE_REG:
358 				pnp_write(PNP_SET_LDN, ldn);
359 				pnp_write(qp->arg1, qp->arg2);
360 				break;
361 			}
362 		}
363 	}
364 }
365 
366 /*
367  * Scan Resource Data for Logical Devices.
368  *
369  * This function exits as soon as it gets an error reading *ANY*
370  * Resource Data or ir reaches the end of Resource Data.  In the first
371  * case the return value will be TRUE, FALSE otherwise.
372  */
373 static int
374 pnp_scan_resdata(device_t parent, pnp_id *p, int csn)
375 {
376 	u_char tag, resinfo[16];
377 	int large_len, scanning = 1024, retval = FALSE;
378 	u_int32_t logical_id;
379 	u_int32_t compat_id;
380 	device_t dev = 0;
381 	int ldn = 0;
382 	struct isa_config card, logdev, alt;
383 	struct isa_config *config;
384 	struct pnp_set_config_arg *csnldn;
385 	int priority = 0;
386 	char *desc = 0;
387 
388 	bzero(&card, sizeof card);
389 	bzero(&logdev, sizeof logdev);
390 	bzero(&alt, sizeof alt);
391 	config = &card;
392 	while (scanning-- > 0 && pnp_get_resource_info(&tag, 1)) {
393 		if (PNP_RES_TYPE(tag) == 0) {
394 			/* Small resource */
395 			if (pnp_get_resource_info(resinfo,
396 						  PNP_SRES_LEN(tag)) == 0) {
397 				scanning = 0;
398 				continue;
399 			}
400 
401 			switch (PNP_SRES_NUM(tag)) {
402 			case PNP_TAG_LOGICAL_DEVICE:
403 				/*
404 				 * A new logical device. Scan
405 				 * resourcea and add device.
406 				 */
407 				bcopy(resinfo, &logical_id, 4);
408 				pnp_check_quirks(p->vendor_id,
409 						 logical_id,
410 						 ldn);
411 				compat_id = 0;
412 				logdev = card;
413 				config = &logdev;
414 				dev = BUS_ADD_CHILD(parent,
415 						    ISA_ORDER_PNP, NULL, -1);
416 				if (desc)
417 					device_set_desc_copy(dev, desc);
418 				isa_set_vendorid(dev, p->vendor_id);
419 				isa_set_serial(dev, p->serial);
420 				isa_set_logicalid(dev, logical_id);
421 				csnldn = malloc(sizeof *csnldn,
422 						M_DEVBUF, M_NOWAIT);
423 				if (!csnldn) {
424 					device_printf(parent,
425 						      "out of memory\n");
426 					scanning = 0;
427 					break;
428 				}
429 				csnldn->csn = csn;
430 				csnldn->ldn = ldn;
431 				ISA_SET_CONFIG_CALLBACK(parent, dev,
432 							pnp_set_config,
433 							csnldn);
434 				ldn++;
435 				break;
436 
437 			case PNP_TAG_COMPAT_DEVICE:
438 				/*
439 				 * Got a compatible device id
440 				 * resource. Should keep a list of
441 				 * compat ids in the device.
442 				 */
443 				bcopy(resinfo, &compat_id, 4);
444 				if (dev)
445 					isa_set_compatid(dev, compat_id);
446 				break;
447 
448 			case PNP_TAG_IRQ_FORMAT:
449 				if (config->ic_nirq == ISA_NIRQ) {
450 					device_printf(parent,
451 						      "CSN %d too many irqs",
452 						      csn);
453 					scanning = 0;
454 					break;
455 				}
456 				config->ic_irqmask[config->ic_nirq] =
457 					resinfo[0] + (resinfo[1]<<8);
458 				config->ic_nirq++;
459 				break;
460 
461 			case PNP_TAG_DMA_FORMAT:
462 				if (config->ic_ndrq == ISA_NDRQ) {
463 					device_printf(parent,
464 						      "CSN %d too many drqs",
465 						      csn);
466 					scanning = 0;
467 					break;
468 				}
469 				config->ic_drqmask[config->ic_ndrq] =
470 					resinfo[0];
471 				config->ic_ndrq++;
472 				break;
473 
474 			case PNP_TAG_START_DEPENDANT:
475 				if (config == &alt) {
476 					ISA_ADD_CONFIG(parent, dev,
477 						       priority, config);
478 				} else if (config != &logdev) {
479 					device_printf(parent,
480 						      "CSN %d malformed\n",
481 						      csn);
482 					scanning = 0;
483 					break;
484 				}
485 				/*
486 				 * If the priority is not specified,
487 				 * then use the default of
488 				 * 'acceptable'
489 				 */
490 				if (PNP_SRES_LEN(tag) > 0)
491 					priority = resinfo[0];
492 				else
493 					priority = 1;
494 				alt = logdev;
495 				config = &alt;
496 				break;
497 
498 			case PNP_TAG_END_DEPENDANT:
499 				ISA_ADD_CONFIG(parent, dev, priority, config);
500 				config = &logdev;
501 				break;
502 
503 			case PNP_TAG_IO_RANGE:
504 				if (config->ic_nport == ISA_NPORT) {
505 					device_printf(parent,
506 						      "CSN %d too many ports",
507 						      csn);
508 					scanning = 0;
509 					break;
510 				}
511 				config->ic_port[config->ic_nport].ir_start =
512 					resinfo[1] + (resinfo[2]<<8);
513 				config->ic_port[config->ic_nport].ir_end =
514 					resinfo[3] + (resinfo[4]<<8)
515 					+ resinfo[6] - 1;
516 				config->ic_port[config->ic_nport].ir_size
517 					=
518 					resinfo[6];
519 				config->ic_port[config->ic_nport].ir_align =
520 					resinfo[5];
521 				config->ic_nport++;
522 				break;
523 
524 			case PNP_TAG_IO_FIXED:
525 				if (config->ic_nport == ISA_NPORT) {
526 					device_printf(parent,
527 						      "CSN %d too many ports",
528 						      csn);
529 					scanning = 0;
530 					break;
531 				}
532 				config->ic_port[config->ic_nport].ir_start =
533 					resinfo[0] + (resinfo[1]<<8);
534 				config->ic_port[config->ic_nport].ir_end =
535 					resinfo[0] + (resinfo[1]<<8)
536 					+ resinfo[2] - 1;
537 				config->ic_port[config->ic_nport].ir_size
538 					= resinfo[2];
539 				config->ic_port[config->ic_nport].ir_align = 1;
540 				config->ic_nport++;
541 				break;
542 
543 			case PNP_TAG_END:
544 				scanning = 0;
545 				break;
546 
547 			default:
548 				/* Skip this resource */
549 				break;
550 			}
551 		} else {
552 			/* Large resource */
553 			if (pnp_get_resource_info(resinfo, 2) == 0) {
554 				scanning = 0;
555 				continue;
556 			}
557 			large_len = resinfo[0] + (resinfo[1] << 8);
558 
559 			if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
560 				if (desc)
561 					free(desc, M_TEMP);
562 				desc = malloc(large_len + 1,
563 					      M_TEMP, M_NOWAIT);
564 				/*
565 				 * Note: if malloc fails, this will
566 				 * skip the resource instead of
567 				 * reading it into desc.
568 				 */
569 				if (pnp_get_resource_info(desc,
570 							  large_len) == 0) {
571 					scanning = 0;
572 				}
573 				if (desc) {
574 					/*
575 					 * Trim trailing spaces.
576 					 */
577 					while (desc[large_len-1] == ' ')
578 						large_len--;
579 					desc[large_len] = '\0';
580 					if (dev)
581 						device_set_desc_copy
582 							(dev, desc);
583 				}
584 				continue;
585 			}
586 
587 			if (PNP_LRES_NUM(tag) != PNP_TAG_MEMORY_RANGE) {
588 				/* skip */
589 				if (pnp_get_resource_info(NULL,
590 							  large_len) == 0) {
591 					scanning = 0;
592 				}
593 				continue;
594 			}
595 
596 			if (pnp_get_resource_info(resinfo, large_len) == 0) {
597 				scanning = 0;
598 				continue;
599 			}
600 
601 			if (config->ic_nmem == ISA_NMEM) {
602 				device_printf(parent,
603 					      "CSN %d too many memory ranges",
604 					      csn);
605 				scanning = 0;
606 				break;
607 			}
608 
609 			config->ic_mem[config->ic_nmem].ir_start =
610 				(resinfo[4]<<8) + (resinfo[5]<<16);
611 			config->ic_mem[config->ic_nmem].ir_end =
612 				(resinfo[6]<<8) + (resinfo[7]<<16);
613 			config->ic_mem[config->ic_nmem].ir_size =
614 				(resinfo[10]<<8) + (resinfo[11]<<16);
615 			config->ic_mem[config->ic_nmem].ir_align =
616 				resinfo[8] + (resinfo[9]<<8);
617 			if (!config->ic_mem[config->ic_nmem].ir_align)
618 				config->ic_mem[config->ic_nmem].ir_align =
619 					0x10000;
620 			config->ic_nmem++;
621 		}
622 	}
623 
624 	if (desc)
625 		free(desc, M_TEMP);
626 
627 	return retval;
628 }
629 
630 /*
631  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
632  * value (caller should try multiple READ_DATA locations before giving
633  * up). Upon exiting, all cards are aware that they should use
634  * pnp_rd_port as the READ_DATA port.
635  *
636  * In the first pass, a csn is assigned to each board and pnp_id's
637  * are saved to an array, pnp_devices. In the second pass, each
638  * card is woken up and the device configuration is called.
639  */
640 static int
641 pnp_isolation_protocol(device_t parent)
642 {
643 	int csn;
644 	pnp_id id;
645 	int found = 0;
646 
647 	/*
648 	 * Put all cards into the Sleep state so that we can clear
649 	 * their CSNs.
650 	 */
651 	pnp_send_initiation_key();
652 
653 	/*
654 	 * Clear the CSN for all cards.
655 	 */
656 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
657 
658 	/*
659 	 * Move all cards to the Isolation state.
660 	 */
661 	pnp_write(PNP_WAKE, 0);
662 
663 	/*
664 	 * Tell them where the read point is going to be this time.
665 	 */
666 	pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
667 
668 	for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
669 		/*
670 		 * Start the serial isolation protocol.
671 		 */
672 		outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
673 		DELAY(1000);	/* Delay 1 msec */
674 
675 		if (pnp_get_serial(&id)) {
676 			/*
677 			 * We have read the id from a card
678 			 * successfully. The card which won the
679 			 * isolation protocol will be in Isolation
680 			 * mode and all others will be in Sleep.  *
681 			 * Program the CSN of the isolated card
682 			 * (taking it to Config state) and read its
683 			 * resources, creating devices as we find
684 			 * logical devices on the card.
685 			 */
686 			pnp_write(PNP_SET_CSN, csn);
687 			pnp_scan_resdata(parent, &id, csn);
688 			found++;
689 		} else
690 			break;
691 
692 		/*
693 		 * Put this card back to the Sleep state and
694 		 * simultaneously move all cards which don't have a
695 		 * CSN yet to Isolation state.
696 		 */
697 		pnp_write(PNP_WAKE, 0);
698 	}
699 
700 	/*
701 	 * Unless we have chosen the wrong read port, all cards will
702 	 * be in Sleep state. Put them back into WaitForKey for
703 	 * now. Their resources will be programmed later.
704 	 */
705 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
706 
707 	return found;
708 }
709 
710 
711 /*
712  * pnp_identify()
713  *
714  * autoconfiguration of pnp devices. This routine just runs the
715  * isolation protocol over several ports, until one is successful.
716  *
717  * may be called more than once ?
718  *
719  */
720 
721 static void
722 pnp_identify(driver_t *driver, device_t parent)
723 {
724 	int num_pnp_devs;
725 
726 #if 0
727 	if (pnp_ldn_overrides[0].csn == 0) {
728 		if (bootverbose)
729 			printf("Initializing PnP override table\n");
730 		bzero (pnp_ldn_overrides, sizeof(pnp_ldn_overrides));
731 		pnp_ldn_overrides[0].csn = 255 ;
732 	}
733 #endif
734 
735 	/* Try various READ_DATA ports from 0x203-0x3ff */
736 	for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
737 		if (bootverbose)
738 			printf("Trying Read_Port at %x\n", (pnp_rd_port << 2) | 0x3);
739 
740 		num_pnp_devs = pnp_isolation_protocol(parent);
741 		if (num_pnp_devs)
742 			break;
743 	}
744 }
745 
746 static device_method_t pnp_methods[] = {
747 	/* Device interface */
748 	DEVMETHOD(device_identify,	pnp_identify),
749 
750 	{ 0, 0 }
751 };
752 
753 static driver_t pnp_driver = {
754 	"pnp",
755 	pnp_methods,
756 	1,			/* no softc */
757 };
758 
759 static devclass_t pnp_devclass;
760 
761 DRIVER_MODULE(pnp, isa, pnp_driver, pnp_devclass, 0, 0);
762