xref: /freebsd/sys/isa/pnp.c (revision 7a83aa6339e1a9f1fe894f64d5fa4f579f404d92)
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  *      from: pnp.c,v 1.11 1999/05/06 22:11:19 peter Exp
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
36 #include <sys/bus.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 #ifdef PC98
97 /* Some NEC PnP cards have 9 bytes serial code. */
98 static pnp_id necids[] = {
99 	{0x4180a3b8, 0xffffffff, 0x00},	/* PC-9801CB-B04 (NEC8041) */
100 	{0x5181a3b8, 0xffffffff, 0x46},	/* PC-9821CB2-B04(NEC8151) */
101 	{0x5182a3b8, 0xffffffff, 0xb8},	/* PC-9801-XX    (NEC8251) */
102 	{0x9181a3b8, 0xffffffff, 0x00},	/* PC-9801-120   (NEC8191) */
103 	{0, 0, 0}
104 };
105 #endif
106 
107 /* The READ_DATA port that we are using currently */
108 static int pnp_rd_port;
109 
110 static void   pnp_send_initiation_key(void);
111 static int    pnp_get_serial(pnp_id *p);
112 static int    pnp_isolation_protocol(device_t parent);
113 
114 char *
115 pnp_eisaformat(uint32_t id)
116 {
117 	uint8_t *data = (uint8_t *) &id;
118 	static char idbuf[8];
119 	const char  hextoascii[] = "0123456789abcdef";
120 
121 	idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
122 	idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
123 	idbuf[2] = '@' + (data[1] & 0x1f);
124 	idbuf[3] = hextoascii[(data[2] >> 4)];
125 	idbuf[4] = hextoascii[(data[2] & 0xf)];
126 	idbuf[5] = hextoascii[(data[3] >> 4)];
127 	idbuf[6] = hextoascii[(data[3] & 0xf)];
128 	idbuf[7] = 0;
129 	return(idbuf);
130 }
131 
132 static void
133 pnp_write(int d, u_char r)
134 {
135 	outb (_PNP_ADDRESS, d);
136 	outb (_PNP_WRITE_DATA, r);
137 }
138 
139 /*
140  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
141  * Intel May 94.
142  */
143 static void
144 pnp_send_initiation_key()
145 {
146 	int cur, i;
147 
148 	/* Reset the LSFR */
149 	outb(_PNP_ADDRESS, 0);
150 	outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
151 
152 	cur = 0x6a;
153 	outb(_PNP_ADDRESS, cur);
154 
155 	for (i = 1; i < 32; i++) {
156 		cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
157 		outb(_PNP_ADDRESS, cur);
158 	}
159 }
160 
161 
162 /*
163  * Get the device's serial number.  Returns 1 if the serial is valid.
164  */
165 static int
166 pnp_get_serial(pnp_id *p)
167 {
168 	int i, bit, valid = 0, sum = 0x6a;
169 	u_char *data = (u_char *)p;
170 
171 	bzero(data, sizeof(char) * 9);
172 	outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
173 	for (i = 0; i < 72; i++) {
174 		bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
175 		DELAY(250);	/* Delay 250 usec */
176 
177 		/* Can't Short Circuit the next evaluation, so 'and' is last */
178 		bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
179 		DELAY(250);	/* Delay 250 usec */
180 
181 		valid = valid || bit;
182 		if (i < 64)
183 			sum = (sum >> 1) |
184 			  (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
185 		data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
186 	}
187 
188 	valid = valid && (data[8] == sum);
189 
190 	return (valid);
191 }
192 
193 /*
194  * Fill's the buffer with resource info from the device.
195  * Returns the number of characters read.
196  */
197 static int
198 pnp_get_resource_info(u_char *buffer, int len)
199 {
200 	int i, j, count;
201 	u_char temp;
202 
203 	count = 0;
204 	for (i = 0; i < len; i++) {
205 		outb(_PNP_ADDRESS, PNP_STATUS);
206 		for (j = 0; j < 100; j++) {
207 			if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
208 				break;
209 			DELAY(1);
210 		}
211 		if (j == 100) {
212 			printf("PnP device failed to report resource data\n");
213 			return (count);
214 		}
215 		outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
216 		temp = inb((pnp_rd_port << 2) | 0x3);
217 		if (buffer != NULL)
218 			buffer[i] = temp;
219 		count++;
220 	}
221 	return (count);
222 }
223 
224 /*
225  * This function is called after the bus has assigned resource
226  * locations for a logical device.
227  */
228 static void
229 pnp_set_config(void *arg, struct isa_config *config, int enable)
230 {
231 	int csn = ((struct pnp_set_config_arg *) arg)->csn;
232 	int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
233 	int i;
234 
235 	/*
236 	 * First put all cards into Sleep state with the initiation
237 	 * key, then put our card into Config state.
238 	 */
239 	pnp_send_initiation_key();
240 	pnp_write(PNP_WAKE, csn);
241 
242 	/*
243 	 * Select our logical device so that we can program it.
244 	 */
245 	pnp_write(PNP_SET_LDN, ldn);
246 
247 	/*
248 	 * Constrain the number of resources we will try to program
249 	 */
250 	if (config->ic_nmem > ISA_PNP_NMEM) {
251 		printf("too many ISA memory ranges (%d > %d)\n",
252 		    config->ic_nmem, ISA_PNP_NMEM);
253 		config->ic_nmem = ISA_PNP_NMEM;
254 	}
255 	if (config->ic_nport > ISA_PNP_NPORT) {
256 		printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
257 		    ISA_PNP_NPORT);
258 		config->ic_nport = ISA_PNP_NPORT;
259 	}
260 	if (config->ic_nirq > ISA_PNP_NIRQ) {
261 		printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
262 		    ISA_PNP_NIRQ);
263 		config->ic_nirq = ISA_PNP_NIRQ;
264 	}
265 	if (config->ic_ndrq > ISA_PNP_NDRQ) {
266 		printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
267 		    ISA_PNP_NDRQ);
268 		config->ic_ndrq = ISA_PNP_NDRQ;
269 	}
270 
271 	/*
272 	 * Now program the resources.
273 	 */
274 	for (i = 0; i < config->ic_nmem; i++) {
275 		uint32_t start;
276 		uint32_t size;
277 
278 		/* XXX: should handle memory control register, 32 bit memory */
279 		if (config->ic_mem[i].ir_size == 0) {
280 			pnp_write(PNP_MEM_BASE_HIGH(i), 0);
281 			pnp_write(PNP_MEM_BASE_LOW(i), 0);
282 			pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
283 			pnp_write(PNP_MEM_RANGE_LOW(i), 0);
284 		} else {
285 			start = config->ic_mem[i].ir_start;
286 			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 	}
295 	for (; i < ISA_PNP_NMEM; i++) {
296 		pnp_write(PNP_MEM_BASE_HIGH(i), 0);
297 		pnp_write(PNP_MEM_BASE_LOW(i), 0);
298 		pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
299 		pnp_write(PNP_MEM_RANGE_LOW(i), 0);
300 	}
301 
302 	for (i = 0; i < config->ic_nport; i++) {
303 		uint32_t start;
304 
305 		if (config->ic_port[i].ir_size == 0) {
306 			pnp_write(PNP_IO_BASE_HIGH(i), 0);
307 			pnp_write(PNP_IO_BASE_LOW(i), 0);
308 		} else {
309 			start = config->ic_port[i].ir_start;
310 			pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
311 			pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
312 		}
313 	}
314 	for (; i < ISA_PNP_NPORT; i++) {
315 		pnp_write(PNP_IO_BASE_HIGH(i), 0);
316 		pnp_write(PNP_IO_BASE_LOW(i), 0);
317 	}
318 
319 	for (i = 0; i < config->ic_nirq; i++) {
320 		int irq;
321 
322 		/* XXX: interrupt type */
323 		if (config->ic_irqmask[i] == 0) {
324 			pnp_write(PNP_IRQ_LEVEL(i), 0);
325 			pnp_write(PNP_IRQ_TYPE(i), 2);
326 		} else {
327 			irq = ffs(config->ic_irqmask[i]) - 1;
328 			pnp_write(PNP_IRQ_LEVEL(i), irq);
329 			pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
330 		}
331 	}
332 	for (; i < ISA_PNP_NIRQ; i++) {
333 		/*
334 		 * IRQ 0 is not a valid interrupt selection and
335 		 * represents no interrupt selection.
336 		 */
337 		pnp_write(PNP_IRQ_LEVEL(i), 0);
338 		pnp_write(PNP_IRQ_TYPE(i), 2);
339 	}
340 
341 	for (i = 0; i < config->ic_ndrq; i++) {
342 		int drq;
343 
344 		if (config->ic_drqmask[i] == 0) {
345 			pnp_write(PNP_DMA_CHANNEL(i), 4);
346 		} else {
347 			drq = ffs(config->ic_drqmask[i]) - 1;
348 			pnp_write(PNP_DMA_CHANNEL(i), drq);
349 		}
350 	}
351 	for (; i < ISA_PNP_NDRQ; i++) {
352 		/*
353 		 * DMA channel 4, the cascade channel is used to
354 		 * indicate no DMA channel is active.
355 		 */
356 		pnp_write(PNP_DMA_CHANNEL(i), 4);
357 	}
358 
359 	pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
360 
361 	/*
362 	 * Wake everyone up again, we are finished.
363 	 */
364 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
365 }
366 
367 /*
368  * Process quirks for a logical device.. The card must be in Config state.
369  */
370 void
371 pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
372     struct isa_config *config)
373 {
374 	struct pnp_quirk *qp;
375 
376 	for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
377 		if (qp->vendor_id == vendor_id
378 		    && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
379 			switch (qp->type) {
380 			case PNP_QUIRK_WRITE_REG:
381 				pnp_write(PNP_SET_LDN, ldn);
382 				pnp_write(qp->arg1, qp->arg2);
383 				break;
384 			case PNP_QUIRK_EXTRA_IO:
385 				if (config == NULL)
386 					break;
387 				if (qp->arg1 != 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->arg1;
391 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
392 				}
393 				if (qp->arg2 != 0) {
394 					config->ic_nport++;
395 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
396 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
397 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
398 				}
399 				break;
400 			}
401 		}
402 	}
403 }
404 
405 /*
406  * Scan Resource Data for Logical Devices.
407  *
408  * This function exits as soon as it gets an error reading *ANY*
409  * Resource Data or it reaches the end of Resource Data.  In the first
410  * case the return value will be TRUE, FALSE otherwise.
411  */
412 static int
413 pnp_create_devices(device_t parent, pnp_id *p, int csn,
414     u_char *resources, int len)
415 {
416 	u_char tag, *resp, *resinfo, *startres = 0;
417 	int large_len, scanning = len, retval = FALSE;
418 	uint32_t logical_id;
419 	device_t dev = 0;
420 	int ldn = 0;
421 	struct pnp_set_config_arg *csnldn;
422 	char buf[100];
423 	char *desc = 0;
424 
425 	resp = resources;
426 	while (scanning > 0) {
427 		tag = *resp++;
428 		scanning--;
429 		if (PNP_RES_TYPE(tag) != 0) {
430 			/* Large resource */
431 			if (scanning < 2) {
432 				scanning = 0;
433 				continue;
434 			}
435 			large_len = resp[0] + (resp[1] << 8);
436 			resp += 2;
437 
438 			if (scanning < large_len) {
439 				scanning = 0;
440 				continue;
441 			}
442 			resinfo = resp;
443 			resp += large_len;
444 			scanning -= large_len;
445 
446 			if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
447 				if (dev) {
448 					/*
449 					 * This is an optional device
450 					 * indentifier string. Skipt it
451 					 * for now.
452 					 */
453 					continue;
454 				}
455 				/* else mandately card identifier string */
456 				if (large_len > sizeof(buf) - 1)
457 					large_len = sizeof(buf) - 1;
458 				bcopy(resinfo, buf, large_len);
459 
460 				/*
461 				 * Trim trailing spaces.
462 				 */
463 				while (buf[large_len-1] == ' ')
464 					large_len--;
465 				buf[large_len] = '\0';
466 				desc = buf;
467 				continue;
468 			}
469 
470 			continue;
471 		}
472 
473 		/* Small resource */
474 		if (scanning < PNP_SRES_LEN(tag)) {
475 			scanning = 0;
476 			continue;
477 		}
478 		resinfo = resp;
479 		resp += PNP_SRES_LEN(tag);
480 		scanning -= PNP_SRES_LEN(tag);;
481 
482 		switch (PNP_SRES_NUM(tag)) {
483 		case PNP_TAG_LOGICAL_DEVICE:
484 			/*
485 			 * Parse the resources for the previous
486 			 * logical device (if any).
487 			 */
488 			if (startres) {
489 				pnp_parse_resources(dev, startres,
490 				    resinfo - startres - 1, ldn);
491 				dev = 0;
492 				startres = 0;
493 			}
494 
495 			/*
496 			 * A new logical device. Scan for end of
497 			 * resources.
498 			 */
499 			bcopy(resinfo, &logical_id, 4);
500 			pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
501 			dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
502 			if (desc)
503 				device_set_desc_copy(dev, desc);
504 			else
505 				device_set_desc_copy(dev,
506 				    pnp_eisaformat(logical_id));
507 			isa_set_vendorid(dev, p->vendor_id);
508 			isa_set_serial(dev, p->serial);
509 			isa_set_logicalid(dev, logical_id);
510 			isa_set_configattr(dev,
511 			    ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
512 			csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
513 			if (!csnldn) {
514 				device_printf(parent, "out of memory\n");
515 				scanning = 0;
516 				break;
517 			}
518 			csnldn->csn = csn;
519 			csnldn->ldn = ldn;
520 			ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
521 			    csnldn);
522 			ldn++;
523 			startres = resp;
524 			break;
525 
526 		case PNP_TAG_END:
527 			if (!startres) {
528 				device_printf(parent, "malformed resources\n");
529 				scanning = 0;
530 				break;
531 			}
532 			pnp_parse_resources(dev, startres,
533 			    resinfo - startres - 1, ldn);
534 			dev = 0;
535 			startres = 0;
536 			scanning = 0;
537 			break;
538 
539 		default:
540 			/* Skip this resource */
541 			break;
542 		}
543 	}
544 
545 	return (retval);
546 }
547 
548 /*
549  * Read 'amount' bytes of resources from the card, allocating memory
550  * as needed. If a buffer is already available, it should be passed in
551  * '*resourcesp' and its length in '*spacep'. The number of resource
552  * bytes already in the buffer should be passed in '*lenp'. The memory
553  * allocated will be returned in '*resourcesp' with its size and the
554  * number of bytes of resources in '*spacep' and '*lenp' respectively.
555  *
556  * XXX: Multiple problems here, we forget to free() stuff in one
557  * XXX: error return, and in another case we free (*resourcesp) but
558  * XXX: don't tell the caller.
559  */
560 static int
561 pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
562 {
563 	u_char *resources = *resourcesp;
564 	u_char *newres;
565 	int space = *spacep;
566 	int len = *lenp;
567 
568 	if (space == 0) {
569 		space = 1024;
570 		resources = malloc(space, M_TEMP, M_NOWAIT);
571 		if (!resources)
572 			return (ENOMEM);
573 	}
574 
575 	if (len + amount > space) {
576 		int extra = 1024;
577 		while (len + amount > space + extra)
578 			extra += 1024;
579 		newres = malloc(space + extra, M_TEMP, M_NOWAIT);
580 		if (!newres) {
581 			/* XXX: free resources */
582 			return (ENOMEM);
583 		}
584 		bcopy(resources, newres, len);
585 		free(resources, M_TEMP);
586 		resources = newres;
587 		space += extra;
588 	}
589 
590 	if (pnp_get_resource_info(resources + len, amount) != amount)
591 		return (EINVAL);
592 	len += amount;
593 
594 	*resourcesp = resources;
595 	*spacep = space;
596 	*lenp = len;
597 
598 	return (0);
599 }
600 
601 /*
602  * Read all resources from the card, allocating memory as needed. If a
603  * buffer is already available, it should be passed in '*resourcesp'
604  * and its length in '*spacep'. The memory allocated will be returned
605  * in '*resourcesp' with its size and the number of bytes of resources
606  * in '*spacep' and '*lenp' respectively.
607  */
608 static int
609 pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
610 {
611 	u_char *resources = *resourcesp;
612 	int space = *spacep;
613 	int len = 0;
614 	int error, done;
615 	u_char tag;
616 
617 	error = 0;
618 	done = 0;
619 	while (!done) {
620 		error = pnp_read_bytes(1, &resources, &space, &len);
621 		if (error)
622 			goto out;
623 		tag = resources[len-1];
624 		if (PNP_RES_TYPE(tag) == 0) {
625 			/*
626 			 * Small resource, read contents.
627 			 */
628 			error = pnp_read_bytes(PNP_SRES_LEN(tag),
629 			    &resources, &space, &len);
630 			if (error)
631 				goto out;
632 			if (PNP_SRES_NUM(tag) == PNP_TAG_END)
633 				done = 1;
634 		} else {
635 			/*
636 			 * Large resource, read length and contents.
637 			 */
638 			error = pnp_read_bytes(2, &resources, &space, &len);
639 			if (error)
640 				goto out;
641 			error = pnp_read_bytes(resources[len-2]
642 			    + (resources[len-1] << 8), &resources, &space,
643 			    &len);
644 			if (error)
645 				goto out;
646 		}
647 	}
648 
649  out:
650 	*resourcesp = resources;
651 	*spacep = space;
652 	*lenp = len;
653 	return (error);
654 }
655 
656 /*
657  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
658  * value (caller should try multiple READ_DATA locations before giving
659  * up). Upon exiting, all cards are aware that they should use
660  * pnp_rd_port as the READ_DATA port.
661  *
662  * In the first pass, a csn is assigned to each board and pnp_id's
663  * are saved to an array, pnp_devices. In the second pass, each
664  * card is woken up and the device configuration is called.
665  */
666 static int
667 pnp_isolation_protocol(device_t parent)
668 {
669 	int csn;
670 	pnp_id id;
671 	int found = 0, len;
672 	u_char *resources = 0;
673 	int space = 0;
674 	int error;
675 #ifdef PC98
676 	int n, necpnp;
677 	u_char buffer[10];
678 #endif
679 
680 	/*
681 	 * Put all cards into the Sleep state so that we can clear
682 	 * their CSNs.
683 	 */
684 	pnp_send_initiation_key();
685 
686 	/*
687 	 * Clear the CSN for all cards.
688 	 */
689 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
690 
691 	/*
692 	 * Move all cards to the Isolation state.
693 	 */
694 	pnp_write(PNP_WAKE, 0);
695 
696 	/*
697 	 * Tell them where the read point is going to be this time.
698 	 */
699 	pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
700 
701 	for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
702 		/*
703 		 * Start the serial isolation protocol.
704 		 */
705 		outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
706 		DELAY(1000);	/* Delay 1 msec */
707 
708 		if (pnp_get_serial(&id)) {
709 			/*
710 			 * We have read the id from a card
711 			 * successfully. The card which won the
712 			 * isolation protocol will be in Isolation
713 			 * mode and all others will be in Sleep.
714 			 * Program the CSN of the isolated card
715 			 * (taking it to Config state) and read its
716 			 * resources, creating devices as we find
717 			 * logical devices on the card.
718 			 */
719 			pnp_write(PNP_SET_CSN, csn);
720 #ifdef PC98
721 			if (bootverbose)
722 				printf("PnP Vendor ID = %x\n", id.vendor_id);
723 			/* Check for NEC PnP (9 bytes serial). */
724 			for (n = necpnp = 0; necids[n].vendor_id; n++) {
725 				if (id.vendor_id == necids[n].vendor_id) {
726 					necpnp = 1;
727 					break;
728 				}
729 			}
730 			if (necpnp) {
731 				if (bootverbose)
732 					printf("An NEC-PnP card (%s).\n",
733 					    pnp_eisaformat(id.vendor_id));
734 				/*  Read dummy 9 bytes serial area. */
735 				pnp_get_resource_info(buffer, 9);
736 			} else {
737 				if (bootverbose)
738 					printf("A Normal-ISA-PnP card (%s).\n",
739 					    pnp_eisaformat(id.vendor_id));
740 			}
741 			if (bootverbose)
742 				printf("Reading PnP configuration for %s.\n",
743 				    pnp_eisaformat(id.vendor_id));
744 #endif
745 			error = pnp_read_resources(&resources, &space, &len);
746 			if (error)
747 				break;
748 			pnp_create_devices(parent, &id, csn, resources, len);
749 			found++;
750 		} else
751 			break;
752 
753 		/*
754 		 * Put this card back to the Sleep state and
755 		 * simultaneously move all cards which don't have a
756 		 * CSN yet to Isolation state.
757 		 */
758 		pnp_write(PNP_WAKE, 0);
759 	}
760 
761 	/*
762 	 * Unless we have chosen the wrong read port, all cards will
763 	 * be in Sleep state. Put them back into WaitForKey for
764 	 * now. Their resources will be programmed later.
765 	 */
766 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
767 
768 	/*
769 	 * Cleanup.
770 	 */
771 	if (resources)
772 		free(resources, M_TEMP);
773 
774 	return (found);
775 }
776 
777 
778 /*
779  * pnp_identify()
780  *
781  * autoconfiguration of pnp devices. This routine just runs the
782  * isolation protocol over several ports, until one is successful.
783  *
784  * may be called more than once ?
785  *
786  */
787 
788 static void
789 pnp_identify(driver_t *driver, device_t parent)
790 {
791 	int num_pnp_devs;
792 
793 	/* Try various READ_DATA ports from 0x203-0x3ff */
794 	for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
795 		if (bootverbose)
796 			printf("Trying Read_Port at %x\n",
797 			    (pnp_rd_port << 2) | 0x3);
798 
799 		num_pnp_devs = pnp_isolation_protocol(parent);
800 		if (num_pnp_devs)
801 			break;
802 	}
803 }
804 
805 static device_method_t pnp_methods[] = {
806 	/* Device interface */
807 	DEVMETHOD(device_identify,	pnp_identify),
808 
809 	{ 0, 0 }
810 };
811 
812 static driver_t pnp_driver = {
813 	"pnp",
814 	pnp_methods,
815 	1,			/* no softc */
816 };
817 
818 static devclass_t pnp_devclass;
819 
820 DRIVER_MODULE(pnp, isa, pnp_driver, pnp_devclass, 0, 0);
821