xref: /freebsd/sys/isa/pnp.c (revision 87b759f0fa1f7554d50ce640c40138512bbded44)
1 /*
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/bus.h>
36 #include <sys/endian.h>
37 #include <sys/malloc.h>
38 #include <isa/isavar.h>
39 #include <isa/pnpreg.h>
40 #include <isa/pnpvar.h>
41 #include <machine/bus.h>
42 
43 typedef struct _pnp_id {
44 	uint32_t vendor_id;
45 	uint32_t serial;
46 	u_char checksum;
47 } pnp_id;
48 
49 struct pnp_set_config_arg {
50 	int	csn;		/* Card number to configure */
51 	int	ldn;		/* Logical device on card */
52 };
53 
54 struct pnp_quirk {
55 	uint32_t vendor_id;	/* Vendor of the card */
56 	uint32_t logical_id;	/* ID of the device with quirk */
57 	int	type;
58 #define PNP_QUIRK_WRITE_REG	1 /* Need to write a pnp register  */
59 #define PNP_QUIRK_EXTRA_IO	2 /* Has extra io ports  */
60 	int	arg1;
61 	int	arg2;
62 };
63 
64 struct pnp_quirk pnp_quirks[] = {
65 	/*
66 	 * The Gravis UltraSound needs register 0xf2 to be set to 0xff
67 	 * to enable power.
68 	 * XXX need to know the logical device id.
69 	 */
70 	{ 0x0100561e /* GRV0001 */,	0,
71 	  PNP_QUIRK_WRITE_REG,	0xf2,	 0xff },
72 	/*
73 	 * An emu8000 does not give us other than the first
74 	 * port.
75 	 */
76 	{ 0x26008c0e /* SB16 */,	0x21008c0e,
77 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
78 	{ 0x42008c0e /* SB32(CTL0042) */,	0x21008c0e,
79 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
80 	{ 0x44008c0e /* SB32(CTL0044) */,	0x21008c0e,
81 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
82 	{ 0x49008c0e /* SB32(CTL0049) */,	0x21008c0e,
83 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
84 	{ 0xf1008c0e /* SB32(CTL00f1) */,	0x21008c0e,
85 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
86 	{ 0xc1008c0e /* SB64(CTL00c1) */,	0x22008c0e,
87 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
88 	{ 0xc5008c0e /* SB64(CTL00c5) */,	0x22008c0e,
89 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
90 	{ 0xe4008c0e /* SB64(CTL00e4) */,	0x22008c0e,
91 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
92 
93 	{ 0 }
94 };
95 
96 /* The READ_DATA port that we are using currently */
97 static int pnp_rd_port;
98 
99 static void   pnp_send_initiation_key(void);
100 static int    pnp_get_serial(pnp_id *p);
101 static int    pnp_isolation_protocol(device_t parent);
102 
103 static void
104 pnp_write(int d, u_char r)
105 {
106 	outb (_PNP_ADDRESS, d);
107 	outb (_PNP_WRITE_DATA, r);
108 }
109 
110 /*
111  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
112  * Intel May 94.
113  */
114 static void
115 pnp_send_initiation_key(void)
116 {
117 	int cur, i;
118 
119 	/* Reset the LSFR */
120 	outb(_PNP_ADDRESS, 0);
121 	outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
122 
123 	cur = 0x6a;
124 	outb(_PNP_ADDRESS, cur);
125 
126 	for (i = 1; i < 32; i++) {
127 		cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
128 		outb(_PNP_ADDRESS, cur);
129 	}
130 }
131 
132 
133 /*
134  * Get the device's serial number.  Returns 1 if the serial is valid.
135  */
136 static int
137 pnp_get_serial(pnp_id *p)
138 {
139 	int i, bit, valid = 0, sum = 0x6a;
140 	u_char *data = (u_char *)p;
141 
142 	bzero(data, sizeof(char) * 9);
143 	outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
144 	for (i = 0; i < 72; i++) {
145 		bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
146 		DELAY(250);	/* Delay 250 usec */
147 
148 		/* Can't Short Circuit the next evaluation, so 'and' is last */
149 		bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
150 		DELAY(250);	/* Delay 250 usec */
151 
152 		valid = valid || bit;
153 		if (i < 64)
154 			sum = (sum >> 1) |
155 			  (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
156 		data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
157 	}
158 
159 	valid = valid && (data[8] == sum);
160 
161 	return (valid);
162 }
163 
164 /*
165  * Fill's the buffer with resource info from the device.
166  * Returns the number of characters read.
167  */
168 static int
169 pnp_get_resource_info(u_char *buffer, int len)
170 {
171 	int i, j, count;
172 	u_char temp;
173 
174 	count = 0;
175 	for (i = 0; i < len; i++) {
176 		outb(_PNP_ADDRESS, PNP_STATUS);
177 		for (j = 0; j < 100; j++) {
178 			if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
179 				break;
180 			DELAY(10);
181 		}
182 		if (j == 100) {
183 			printf("PnP device failed to report resource data\n");
184 			return (count);
185 		}
186 		outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
187 		temp = inb((pnp_rd_port << 2) | 0x3);
188 		if (buffer != NULL)
189 			buffer[i] = temp;
190 		count++;
191 	}
192 	return (count);
193 }
194 
195 /*
196  * This function is called after the bus has assigned resource
197  * locations for a logical device.
198  */
199 static void
200 pnp_set_config(void *arg, struct isa_config *config, int enable)
201 {
202 	int csn = ((struct pnp_set_config_arg *) arg)->csn;
203 	int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
204 	int i;
205 
206 	/*
207 	 * First put all cards into Sleep state with the initiation
208 	 * key, then put our card into Config state.
209 	 */
210 	pnp_send_initiation_key();
211 	pnp_write(PNP_WAKE, csn);
212 
213 	/*
214 	 * Select our logical device so that we can program it.
215 	 */
216 	pnp_write(PNP_SET_LDN, ldn);
217 
218 	/*
219 	 * Constrain the number of resources we will try to program
220 	 */
221 	if (config->ic_nmem > ISA_PNP_NMEM) {
222 		printf("too many ISA memory ranges (%d > %d)\n",
223 		    config->ic_nmem, ISA_PNP_NMEM);
224 		config->ic_nmem = ISA_PNP_NMEM;
225 	}
226 	if (config->ic_nport > ISA_PNP_NPORT) {
227 		printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
228 		    ISA_PNP_NPORT);
229 		config->ic_nport = ISA_PNP_NPORT;
230 	}
231 	if (config->ic_nirq > ISA_PNP_NIRQ) {
232 		printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
233 		    ISA_PNP_NIRQ);
234 		config->ic_nirq = ISA_PNP_NIRQ;
235 	}
236 	if (config->ic_ndrq > ISA_PNP_NDRQ) {
237 		printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
238 		    ISA_PNP_NDRQ);
239 		config->ic_ndrq = ISA_PNP_NDRQ;
240 	}
241 
242 	/*
243 	 * Now program the resources.
244 	 */
245 	for (i = 0; i < config->ic_nmem; i++) {
246 		uint32_t start;
247 		uint32_t size;
248 
249 		/* XXX: should handle memory control register, 32 bit memory */
250 		if (config->ic_mem[i].ir_size == 0) {
251 			pnp_write(PNP_MEM_BASE_HIGH(i), 0);
252 			pnp_write(PNP_MEM_BASE_LOW(i), 0);
253 			pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
254 			pnp_write(PNP_MEM_RANGE_LOW(i), 0);
255 		} else {
256 			start = config->ic_mem[i].ir_start;
257 			size =  config->ic_mem[i].ir_size;
258 			if (start & 0xff)
259 				panic("pnp_set_config: bogus memory assignment");
260 			pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
261 			pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
262 			pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
263 			pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
264 		}
265 	}
266 	for (; i < ISA_PNP_NMEM; i++) {
267 		pnp_write(PNP_MEM_BASE_HIGH(i), 0);
268 		pnp_write(PNP_MEM_BASE_LOW(i), 0);
269 		pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
270 		pnp_write(PNP_MEM_RANGE_LOW(i), 0);
271 	}
272 
273 	for (i = 0; i < config->ic_nport; i++) {
274 		uint32_t start;
275 
276 		if (config->ic_port[i].ir_size == 0) {
277 			pnp_write(PNP_IO_BASE_HIGH(i), 0);
278 			pnp_write(PNP_IO_BASE_LOW(i), 0);
279 		} else {
280 			start = config->ic_port[i].ir_start;
281 			pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
282 			pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
283 		}
284 	}
285 	for (; i < ISA_PNP_NPORT; i++) {
286 		pnp_write(PNP_IO_BASE_HIGH(i), 0);
287 		pnp_write(PNP_IO_BASE_LOW(i), 0);
288 	}
289 
290 	for (i = 0; i < config->ic_nirq; i++) {
291 		int irq;
292 
293 		/* XXX: interrupt type */
294 		if (config->ic_irqmask[i] == 0) {
295 			pnp_write(PNP_IRQ_LEVEL(i), 0);
296 			pnp_write(PNP_IRQ_TYPE(i), 2);
297 		} else {
298 			irq = ffs(config->ic_irqmask[i]) - 1;
299 			pnp_write(PNP_IRQ_LEVEL(i), irq);
300 			pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
301 		}
302 	}
303 	for (; i < ISA_PNP_NIRQ; i++) {
304 		/*
305 		 * IRQ 0 is not a valid interrupt selection and
306 		 * represents no interrupt selection.
307 		 */
308 		pnp_write(PNP_IRQ_LEVEL(i), 0);
309 		pnp_write(PNP_IRQ_TYPE(i), 2);
310 	}
311 
312 	for (i = 0; i < config->ic_ndrq; i++) {
313 		int drq;
314 
315 		if (config->ic_drqmask[i] == 0) {
316 			pnp_write(PNP_DMA_CHANNEL(i), 4);
317 		} else {
318 			drq = ffs(config->ic_drqmask[i]) - 1;
319 			pnp_write(PNP_DMA_CHANNEL(i), drq);
320 		}
321 	}
322 	for (; i < ISA_PNP_NDRQ; i++) {
323 		/*
324 		 * DMA channel 4, the cascade channel is used to
325 		 * indicate no DMA channel is active.
326 		 */
327 		pnp_write(PNP_DMA_CHANNEL(i), 4);
328 	}
329 
330 	pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
331 
332 	/*
333 	 * Wake everyone up again, we are finished.
334 	 */
335 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
336 }
337 
338 /*
339  * Process quirks for a logical device.. The card must be in Config state.
340  */
341 void
342 pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
343     struct isa_config *config)
344 {
345 	struct pnp_quirk *qp;
346 
347 	for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
348 		if (qp->vendor_id == vendor_id
349 		    && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
350 			switch (qp->type) {
351 			case PNP_QUIRK_WRITE_REG:
352 				pnp_write(PNP_SET_LDN, ldn);
353 				pnp_write(qp->arg1, qp->arg2);
354 				break;
355 			case PNP_QUIRK_EXTRA_IO:
356 				if (config == NULL)
357 					break;
358 				if (qp->arg1 != 0) {
359 					config->ic_nport++;
360 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
361 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg1;
362 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
363 				}
364 				if (qp->arg2 != 0) {
365 					config->ic_nport++;
366 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
367 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
368 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
369 				}
370 				break;
371 			}
372 		}
373 	}
374 }
375 
376 /*
377  * Scan Resource Data for Logical Devices.
378  *
379  * This function exits as soon as it gets an error reading *ANY*
380  * Resource Data or it reaches the end of Resource Data.  In the first
381  * case the return value will be TRUE, FALSE otherwise.
382  */
383 static int
384 pnp_create_devices(device_t parent, pnp_id *p, int csn,
385     u_char *resources, int len)
386 {
387 	u_char tag, *resp, *resinfo, *startres = NULL;
388 	int large_len, scanning = len, retval = FALSE;
389 	uint32_t logical_id;
390 	device_t dev = 0;
391 	int ldn = 0;
392 	struct pnp_set_config_arg *csnldn;
393 	char buf[100];
394 	char *desc = NULL;
395 
396 	resp = resources;
397 	while (scanning > 0) {
398 		tag = *resp++;
399 		scanning--;
400 		if (PNP_RES_TYPE(tag) != 0) {
401 			/* Large resource */
402 			if (scanning < 2) {
403 				scanning = 0;
404 				continue;
405 			}
406 			large_len = resp[0] + (resp[1] << 8);
407 			resp += 2;
408 
409 			if (scanning < large_len) {
410 				scanning = 0;
411 				continue;
412 			}
413 			resinfo = resp;
414 			resp += large_len;
415 			scanning -= large_len;
416 
417 			if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
418 				if (dev) {
419 					/*
420 					 * This is an optional device
421 					 * identifier string. Skip it
422 					 * for now.
423 					 */
424 					continue;
425 				}
426 				/* else mandately card identifier string */
427 				if (large_len > sizeof(buf) - 1)
428 					large_len = sizeof(buf) - 1;
429 				bcopy(resinfo, buf, large_len);
430 
431 				/*
432 				 * Trim trailing spaces.
433 				 */
434 				while (buf[large_len-1] == ' ')
435 					large_len--;
436 				buf[large_len] = '\0';
437 				desc = buf;
438 				continue;
439 			}
440 
441 			continue;
442 		}
443 
444 		/* Small resource */
445 		if (scanning < PNP_SRES_LEN(tag)) {
446 			scanning = 0;
447 			continue;
448 		}
449 		resinfo = resp;
450 		resp += PNP_SRES_LEN(tag);
451 		scanning -= PNP_SRES_LEN(tag);
452 
453 		switch (PNP_SRES_NUM(tag)) {
454 		case PNP_TAG_LOGICAL_DEVICE:
455 			/*
456 			 * Parse the resources for the previous
457 			 * logical device (if any).
458 			 */
459 			if (startres) {
460 				pnp_parse_resources(dev, startres,
461 				    resinfo - startres - 1, ldn);
462 				dev = 0;
463 				startres = NULL;
464 			}
465 
466 			/*
467 			 * A new logical device. Scan for end of
468 			 * resources.
469 			 */
470 			bcopy(resinfo, &logical_id, 4);
471 			pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
472 			dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, DEVICE_UNIT_ANY);
473 			if (desc)
474 				device_set_desc_copy(dev, desc);
475 			else
476 				device_set_desc_copy(dev,
477 				    pnp_eisaformat(logical_id));
478 			isa_set_vendorid(dev, p->vendor_id);
479 			isa_set_serial(dev, p->serial);
480 			isa_set_logicalid(dev, logical_id);
481 			isa_set_configattr(dev,
482 			    ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
483 			csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
484 			if (!csnldn) {
485 				device_printf(parent, "out of memory\n");
486 				scanning = 0;
487 				break;
488 			}
489 			csnldn->csn = csn;
490 			csnldn->ldn = ldn;
491 			ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
492 			    csnldn);
493 			isa_set_pnp_csn(dev, csn);
494 			isa_set_pnp_ldn(dev, ldn);
495 			ldn++;
496 			startres = resp;
497 			break;
498 
499 		case PNP_TAG_END:
500 			if (!startres) {
501 				device_printf(parent, "malformed resources\n");
502 				scanning = 0;
503 				break;
504 			}
505 			pnp_parse_resources(dev, startres,
506 			    resinfo - startres - 1, ldn);
507 			dev = 0;
508 			startres = NULL;
509 			scanning = 0;
510 			break;
511 
512 		default:
513 			/* Skip this resource */
514 			break;
515 		}
516 	}
517 
518 	return (retval);
519 }
520 
521 /*
522  * Read 'amount' bytes of resources from the card, allocating memory
523  * as needed. If a buffer is already available, it should be passed in
524  * '*resourcesp' and its length in '*spacep'. The number of resource
525  * bytes already in the buffer should be passed in '*lenp'. The memory
526  * allocated will be returned in '*resourcesp' with its size and the
527  * number of bytes of resources in '*spacep' and '*lenp' respectively.
528  *
529  * XXX: Multiple problems here, we forget to free() stuff in one
530  * XXX: error return, and in another case we free (*resourcesp) but
531  * XXX: don't tell the caller.
532  */
533 static int
534 pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
535 {
536 	u_char *resources = *resourcesp;
537 	u_char *newres;
538 	int space = *spacep;
539 	int len = *lenp;
540 
541 	if (space == 0) {
542 		space = 1024;
543 		resources = malloc(space, M_TEMP, M_NOWAIT);
544 		if (!resources)
545 			return (ENOMEM);
546 	}
547 
548 	if (len + amount > space) {
549 		int extra = 1024;
550 		while (len + amount > space + extra)
551 			extra += 1024;
552 		newres = malloc(space + extra, M_TEMP, M_NOWAIT);
553 		if (!newres) {
554 			/* XXX: free resources */
555 			return (ENOMEM);
556 		}
557 		bcopy(resources, newres, len);
558 		free(resources, M_TEMP);
559 		resources = newres;
560 		space += extra;
561 	}
562 
563 	if (pnp_get_resource_info(resources + len, amount) != amount)
564 		return (EINVAL);
565 	len += amount;
566 
567 	*resourcesp = resources;
568 	*spacep = space;
569 	*lenp = len;
570 
571 	return (0);
572 }
573 
574 /*
575  * Read all resources from the card, allocating memory as needed. If a
576  * buffer is already available, it should be passed in '*resourcesp'
577  * and its length in '*spacep'. The memory allocated will be returned
578  * in '*resourcesp' with its size and the number of bytes of resources
579  * in '*spacep' and '*lenp' respectively.
580  */
581 static int
582 pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
583 {
584 	u_char *resources = *resourcesp;
585 	int space = *spacep;
586 	int len = 0;
587 	int error, done;
588 	u_char tag;
589 
590 	error = 0;
591 	done = 0;
592 	while (!done) {
593 		error = pnp_read_bytes(1, &resources, &space, &len);
594 		if (error)
595 			goto out;
596 		tag = resources[len-1];
597 		if (PNP_RES_TYPE(tag) == 0) {
598 			/*
599 			 * Small resource, read contents.
600 			 */
601 			error = pnp_read_bytes(PNP_SRES_LEN(tag),
602 			    &resources, &space, &len);
603 			if (error)
604 				goto out;
605 			if (PNP_SRES_NUM(tag) == PNP_TAG_END)
606 				done = 1;
607 		} else {
608 			/*
609 			 * Large resource, read length and contents.
610 			 */
611 			error = pnp_read_bytes(2, &resources, &space, &len);
612 			if (error)
613 				goto out;
614 			error = pnp_read_bytes(resources[len-2]
615 			    + (resources[len-1] << 8), &resources, &space,
616 			    &len);
617 			if (error)
618 				goto out;
619 		}
620 	}
621 
622  out:
623 	*resourcesp = resources;
624 	*spacep = space;
625 	*lenp = len;
626 	return (error);
627 }
628 
629 /*
630  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
631  * value (caller should try multiple READ_DATA locations before giving
632  * up). Upon exiting, all cards are aware that they should use
633  * pnp_rd_port as the READ_DATA port.
634  *
635  * In the first pass, a csn is assigned to each board and pnp_id's
636  * are saved to an array, pnp_devices. In the second pass, each
637  * card is woken up and the device configuration is called.
638  */
639 static int
640 pnp_isolation_protocol(device_t parent)
641 {
642 	int csn;
643 	pnp_id id;
644 	int found = 0, len;
645 	u_char *resources = NULL;
646 	int space = 0;
647 	int error;
648 
649 	/*
650 	 * Put all cards into the Sleep state so that we can clear
651 	 * their CSNs.
652 	 */
653 	pnp_send_initiation_key();
654 
655 	/*
656 	 * Clear the CSN for all cards.
657 	 */
658 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
659 
660 	/*
661 	 * Move all cards to the Isolation state.
662 	 */
663 	pnp_write(PNP_WAKE, 0);
664 
665 	/*
666 	 * Tell them where the read point is going to be this time.
667 	 */
668 	pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
669 
670 	for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
671 		/*
672 		 * Start the serial isolation protocol.
673 		 */
674 		outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
675 		DELAY(1000);	/* Delay 1 msec */
676 
677 		if (pnp_get_serial(&id)) {
678 			/*
679 			 * We have read the id from a card
680 			 * successfully. The card which won the
681 			 * isolation protocol will be in Isolation
682 			 * mode and all others will be in Sleep.
683 			 * Program the CSN of the isolated card
684 			 * (taking it to Config state) and read its
685 			 * resources, creating devices as we find
686 			 * logical devices on the card.
687 			 */
688 			pnp_write(PNP_SET_CSN, csn);
689 			if (bootverbose)
690 				printf("Reading PnP configuration for %s.\n",
691 				    pnp_eisaformat(id.vendor_id));
692 			error = pnp_read_resources(&resources, &space, &len);
693 			if (error)
694 				break;
695 			pnp_create_devices(parent, &id, csn, resources, len);
696 			found++;
697 		} else
698 			break;
699 
700 		/*
701 		 * Put this card back to the Sleep state and
702 		 * simultaneously move all cards which don't have a
703 		 * CSN yet to Isolation state.
704 		 */
705 		pnp_write(PNP_WAKE, 0);
706 	}
707 
708 	/*
709 	 * Unless we have chosen the wrong read port, all cards will
710 	 * be in Sleep state. Put them back into WaitForKey for
711 	 * now. Their resources will be programmed later.
712 	 */
713 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
714 
715 	/*
716 	 * Cleanup.
717 	 */
718 	if (resources)
719 		free(resources, M_TEMP);
720 
721 	return (found);
722 }
723 
724 
725 /*
726  * pnp_identify()
727  *
728  * autoconfiguration of pnp devices. This routine just runs the
729  * isolation protocol over several ports, until one is successful.
730  *
731  * may be called more than once ?
732  *
733  */
734 
735 static void
736 pnp_identify(driver_t *driver, device_t parent)
737 {
738 	int num_pnp_devs;
739 
740 	/* Try various READ_DATA ports from 0x203-0x3ff */
741 	for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
742 		if (bootverbose)
743 			printf("pnp_identify: Trying Read_Port at %x\n",
744 			    (pnp_rd_port << 2) | 0x3);
745 
746 		num_pnp_devs = pnp_isolation_protocol(parent);
747 		if (num_pnp_devs)
748 			break;
749 	}
750 	if (bootverbose)
751 		printf("PNP Identify complete\n");
752 }
753 
754 static device_method_t pnp_methods[] = {
755 	/* Device interface */
756 	DEVMETHOD(device_identify,	pnp_identify),
757 
758 	{ 0, 0 }
759 };
760 
761 static driver_t pnp_driver = {
762 	"pnp",
763 	pnp_methods,
764 	1,			/* no softc */
765 };
766 
767 DRIVER_MODULE(pnp, isa, pnp_driver, 0, 0);
768