xref: /freebsd/sys/isa/pnp.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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/endian.h>
38 #include <sys/malloc.h>
39 #include <isa/isavar.h>
40 #include <isa/pnpreg.h>
41 #include <isa/pnpvar.h>
42 #include <machine/bus.h>
43 
44 typedef struct _pnp_id {
45 	uint32_t vendor_id;
46 	uint32_t serial;
47 	u_char checksum;
48 } pnp_id;
49 
50 struct pnp_set_config_arg {
51 	int	csn;		/* Card number to configure */
52 	int	ldn;		/* Logical device on card */
53 };
54 
55 struct pnp_quirk {
56 	uint32_t vendor_id;	/* Vendor of the card */
57 	uint32_t logical_id;	/* ID of the device with quirk */
58 	int	type;
59 #define PNP_QUIRK_WRITE_REG	1 /* Need to write a pnp register  */
60 #define PNP_QUIRK_EXTRA_IO	2 /* Has extra io ports  */
61 	int	arg1;
62 	int	arg2;
63 };
64 
65 struct pnp_quirk pnp_quirks[] = {
66 	/*
67 	 * The Gravis UltraSound needs register 0xf2 to be set to 0xff
68 	 * to enable power.
69 	 * XXX need to know the logical device id.
70 	 */
71 	{ 0x0100561e /* GRV0001 */,	0,
72 	  PNP_QUIRK_WRITE_REG,	0xf2,	 0xff },
73 	/*
74 	 * An emu8000 does not give us other than the first
75 	 * port.
76 	 */
77 	{ 0x26008c0e /* SB16 */,	0x21008c0e,
78 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
79 	{ 0x42008c0e /* SB32(CTL0042) */,	0x21008c0e,
80 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
81 	{ 0x44008c0e /* SB32(CTL0044) */,	0x21008c0e,
82 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
83 	{ 0x49008c0e /* SB32(CTL0049) */,	0x21008c0e,
84 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
85 	{ 0xf1008c0e /* SB32(CTL00f1) */,	0x21008c0e,
86 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
87 	{ 0xc1008c0e /* SB64(CTL00c1) */,	0x22008c0e,
88 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
89 	{ 0xc5008c0e /* SB64(CTL00c5) */,	0x22008c0e,
90 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
91 	{ 0xe4008c0e /* SB64(CTL00e4) */,	0x22008c0e,
92 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
93 
94 	{ 0 }
95 };
96 
97 #ifdef PC98
98 /* Some NEC PnP cards have 9 bytes serial code. */
99 static pnp_id necids[] = {
100 	{0x4180a3b8, 0xffffffff, 0x00},	/* PC-9801CB-B04 (NEC8041) */
101 	{0x5181a3b8, 0xffffffff, 0x46},	/* PC-9821CB2-B04(NEC8151) */
102 	{0x5182a3b8, 0xffffffff, 0xb8},	/* PC-9801-XX    (NEC8251) */
103 	{0x9181a3b8, 0xffffffff, 0x00},	/* PC-9801-120   (NEC8191) */
104 	{0, 0, 0}
105 };
106 #endif
107 
108 /* The READ_DATA port that we are using currently */
109 static int pnp_rd_port;
110 
111 static void   pnp_send_initiation_key(void);
112 static int    pnp_get_serial(pnp_id *p);
113 static int    pnp_isolation_protocol(device_t parent);
114 
115 char *
116 pnp_eisaformat(uint32_t id)
117 {
118 	uint8_t *data;
119 	static char idbuf[8];
120 	const char  hextoascii[] = "0123456789abcdef";
121 
122 	id = htole32(id);
123 	data = (uint8_t *)&id;
124 	idbuf[0] = '@' + ((data[0] & 0x7c) >> 2);
125 	idbuf[1] = '@' + (((data[0] & 0x3) << 3) + ((data[1] & 0xe0) >> 5));
126 	idbuf[2] = '@' + (data[1] & 0x1f);
127 	idbuf[3] = hextoascii[(data[2] >> 4)];
128 	idbuf[4] = hextoascii[(data[2] & 0xf)];
129 	idbuf[5] = hextoascii[(data[3] >> 4)];
130 	idbuf[6] = hextoascii[(data[3] & 0xf)];
131 	idbuf[7] = 0;
132 	return(idbuf);
133 }
134 
135 static void
136 pnp_write(int d, u_char r)
137 {
138 	outb (_PNP_ADDRESS, d);
139 	outb (_PNP_WRITE_DATA, r);
140 }
141 
142 /*
143  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
144  * Intel May 94.
145  */
146 static void
147 pnp_send_initiation_key()
148 {
149 	int cur, i;
150 
151 	/* Reset the LSFR */
152 	outb(_PNP_ADDRESS, 0);
153 	outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
154 
155 	cur = 0x6a;
156 	outb(_PNP_ADDRESS, cur);
157 
158 	for (i = 1; i < 32; i++) {
159 		cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
160 		outb(_PNP_ADDRESS, cur);
161 	}
162 }
163 
164 
165 /*
166  * Get the device's serial number.  Returns 1 if the serial is valid.
167  */
168 static int
169 pnp_get_serial(pnp_id *p)
170 {
171 	int i, bit, valid = 0, sum = 0x6a;
172 	u_char *data = (u_char *)p;
173 
174 	bzero(data, sizeof(char) * 9);
175 	outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
176 	for (i = 0; i < 72; i++) {
177 		bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
178 		DELAY(250);	/* Delay 250 usec */
179 
180 		/* Can't Short Circuit the next evaluation, so 'and' is last */
181 		bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
182 		DELAY(250);	/* Delay 250 usec */
183 
184 		valid = valid || bit;
185 		if (i < 64)
186 			sum = (sum >> 1) |
187 			  (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
188 		data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
189 	}
190 
191 	valid = valid && (data[8] == sum);
192 
193 	return (valid);
194 }
195 
196 /*
197  * Fill's the buffer with resource info from the device.
198  * Returns the number of characters read.
199  */
200 static int
201 pnp_get_resource_info(u_char *buffer, int len)
202 {
203 	int i, j, count;
204 	u_char temp;
205 
206 	count = 0;
207 	for (i = 0; i < len; i++) {
208 		outb(_PNP_ADDRESS, PNP_STATUS);
209 		for (j = 0; j < 100; j++) {
210 			if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
211 				break;
212 			DELAY(1);
213 		}
214 		if (j == 100) {
215 			printf("PnP device failed to report resource data\n");
216 			return (count);
217 		}
218 		outb(_PNP_ADDRESS, PNP_RESOURCE_DATA);
219 		temp = inb((pnp_rd_port << 2) | 0x3);
220 		if (buffer != NULL)
221 			buffer[i] = temp;
222 		count++;
223 	}
224 	return (count);
225 }
226 
227 /*
228  * This function is called after the bus has assigned resource
229  * locations for a logical device.
230  */
231 static void
232 pnp_set_config(void *arg, struct isa_config *config, int enable)
233 {
234 	int csn = ((struct pnp_set_config_arg *) arg)->csn;
235 	int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
236 	int i;
237 
238 	/*
239 	 * First put all cards into Sleep state with the initiation
240 	 * key, then put our card into Config state.
241 	 */
242 	pnp_send_initiation_key();
243 	pnp_write(PNP_WAKE, csn);
244 
245 	/*
246 	 * Select our logical device so that we can program it.
247 	 */
248 	pnp_write(PNP_SET_LDN, ldn);
249 
250 	/*
251 	 * Constrain the number of resources we will try to program
252 	 */
253 	if (config->ic_nmem > ISA_PNP_NMEM) {
254 		printf("too many ISA memory ranges (%d > %d)\n",
255 		    config->ic_nmem, ISA_PNP_NMEM);
256 		config->ic_nmem = ISA_PNP_NMEM;
257 	}
258 	if (config->ic_nport > ISA_PNP_NPORT) {
259 		printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
260 		    ISA_PNP_NPORT);
261 		config->ic_nport = ISA_PNP_NPORT;
262 	}
263 	if (config->ic_nirq > ISA_PNP_NIRQ) {
264 		printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
265 		    ISA_PNP_NIRQ);
266 		config->ic_nirq = ISA_PNP_NIRQ;
267 	}
268 	if (config->ic_ndrq > ISA_PNP_NDRQ) {
269 		printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
270 		    ISA_PNP_NDRQ);
271 		config->ic_ndrq = ISA_PNP_NDRQ;
272 	}
273 
274 	/*
275 	 * Now program the resources.
276 	 */
277 	for (i = 0; i < config->ic_nmem; i++) {
278 		uint32_t start;
279 		uint32_t size;
280 
281 		/* XXX: should handle memory control register, 32 bit memory */
282 		if (config->ic_mem[i].ir_size == 0) {
283 			pnp_write(PNP_MEM_BASE_HIGH(i), 0);
284 			pnp_write(PNP_MEM_BASE_LOW(i), 0);
285 			pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
286 			pnp_write(PNP_MEM_RANGE_LOW(i), 0);
287 		} else {
288 			start = config->ic_mem[i].ir_start;
289 			size =  config->ic_mem[i].ir_size;
290 			if (start & 0xff)
291 				panic("pnp_set_config: bogus memory assignment");
292 			pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
293 			pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
294 			pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
295 			pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
296 		}
297 	}
298 	for (; i < ISA_PNP_NMEM; i++) {
299 		pnp_write(PNP_MEM_BASE_HIGH(i), 0);
300 		pnp_write(PNP_MEM_BASE_LOW(i), 0);
301 		pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
302 		pnp_write(PNP_MEM_RANGE_LOW(i), 0);
303 	}
304 
305 	for (i = 0; i < config->ic_nport; i++) {
306 		uint32_t start;
307 
308 		if (config->ic_port[i].ir_size == 0) {
309 			pnp_write(PNP_IO_BASE_HIGH(i), 0);
310 			pnp_write(PNP_IO_BASE_LOW(i), 0);
311 		} else {
312 			start = config->ic_port[i].ir_start;
313 			pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
314 			pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
315 		}
316 	}
317 	for (; i < ISA_PNP_NPORT; i++) {
318 		pnp_write(PNP_IO_BASE_HIGH(i), 0);
319 		pnp_write(PNP_IO_BASE_LOW(i), 0);
320 	}
321 
322 	for (i = 0; i < config->ic_nirq; i++) {
323 		int irq;
324 
325 		/* XXX: interrupt type */
326 		if (config->ic_irqmask[i] == 0) {
327 			pnp_write(PNP_IRQ_LEVEL(i), 0);
328 			pnp_write(PNP_IRQ_TYPE(i), 2);
329 		} else {
330 			irq = ffs(config->ic_irqmask[i]) - 1;
331 			pnp_write(PNP_IRQ_LEVEL(i), irq);
332 			pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
333 		}
334 	}
335 	for (; i < ISA_PNP_NIRQ; i++) {
336 		/*
337 		 * IRQ 0 is not a valid interrupt selection and
338 		 * represents no interrupt selection.
339 		 */
340 		pnp_write(PNP_IRQ_LEVEL(i), 0);
341 		pnp_write(PNP_IRQ_TYPE(i), 2);
342 	}
343 
344 	for (i = 0; i < config->ic_ndrq; i++) {
345 		int drq;
346 
347 		if (config->ic_drqmask[i] == 0) {
348 			pnp_write(PNP_DMA_CHANNEL(i), 4);
349 		} else {
350 			drq = ffs(config->ic_drqmask[i]) - 1;
351 			pnp_write(PNP_DMA_CHANNEL(i), drq);
352 		}
353 	}
354 	for (; i < ISA_PNP_NDRQ; i++) {
355 		/*
356 		 * DMA channel 4, the cascade channel is used to
357 		 * indicate no DMA channel is active.
358 		 */
359 		pnp_write(PNP_DMA_CHANNEL(i), 4);
360 	}
361 
362 	pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
363 
364 	/*
365 	 * Wake everyone up again, we are finished.
366 	 */
367 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
368 }
369 
370 /*
371  * Process quirks for a logical device.. The card must be in Config state.
372  */
373 void
374 pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
375     struct isa_config *config)
376 {
377 	struct pnp_quirk *qp;
378 
379 	for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
380 		if (qp->vendor_id == vendor_id
381 		    && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
382 			switch (qp->type) {
383 			case PNP_QUIRK_WRITE_REG:
384 				pnp_write(PNP_SET_LDN, ldn);
385 				pnp_write(qp->arg1, qp->arg2);
386 				break;
387 			case PNP_QUIRK_EXTRA_IO:
388 				if (config == NULL)
389 					break;
390 				if (qp->arg1 != 0) {
391 					config->ic_nport++;
392 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
393 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg1;
394 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
395 				}
396 				if (qp->arg2 != 0) {
397 					config->ic_nport++;
398 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
399 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
400 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
401 				}
402 				break;
403 			}
404 		}
405 	}
406 }
407 
408 /*
409  * Scan Resource Data for Logical Devices.
410  *
411  * This function exits as soon as it gets an error reading *ANY*
412  * Resource Data or it reaches the end of Resource Data.  In the first
413  * case the return value will be TRUE, FALSE otherwise.
414  */
415 static int
416 pnp_create_devices(device_t parent, pnp_id *p, int csn,
417     u_char *resources, int len)
418 {
419 	u_char tag, *resp, *resinfo, *startres = 0;
420 	int large_len, scanning = len, retval = FALSE;
421 	uint32_t logical_id;
422 	device_t dev = 0;
423 	int ldn = 0;
424 	struct pnp_set_config_arg *csnldn;
425 	char buf[100];
426 	char *desc = 0;
427 
428 	resp = resources;
429 	while (scanning > 0) {
430 		tag = *resp++;
431 		scanning--;
432 		if (PNP_RES_TYPE(tag) != 0) {
433 			/* Large resource */
434 			if (scanning < 2) {
435 				scanning = 0;
436 				continue;
437 			}
438 			large_len = resp[0] + (resp[1] << 8);
439 			resp += 2;
440 
441 			if (scanning < large_len) {
442 				scanning = 0;
443 				continue;
444 			}
445 			resinfo = resp;
446 			resp += large_len;
447 			scanning -= large_len;
448 
449 			if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
450 				if (dev) {
451 					/*
452 					 * This is an optional device
453 					 * indentifier string. Skipt it
454 					 * for now.
455 					 */
456 					continue;
457 				}
458 				/* else mandately card identifier string */
459 				if (large_len > sizeof(buf) - 1)
460 					large_len = sizeof(buf) - 1;
461 				bcopy(resinfo, buf, large_len);
462 
463 				/*
464 				 * Trim trailing spaces.
465 				 */
466 				while (buf[large_len-1] == ' ')
467 					large_len--;
468 				buf[large_len] = '\0';
469 				desc = buf;
470 				continue;
471 			}
472 
473 			continue;
474 		}
475 
476 		/* Small resource */
477 		if (scanning < PNP_SRES_LEN(tag)) {
478 			scanning = 0;
479 			continue;
480 		}
481 		resinfo = resp;
482 		resp += PNP_SRES_LEN(tag);
483 		scanning -= PNP_SRES_LEN(tag);;
484 
485 		switch (PNP_SRES_NUM(tag)) {
486 		case PNP_TAG_LOGICAL_DEVICE:
487 			/*
488 			 * Parse the resources for the previous
489 			 * logical device (if any).
490 			 */
491 			if (startres) {
492 				pnp_parse_resources(dev, startres,
493 				    resinfo - startres - 1, ldn);
494 				dev = 0;
495 				startres = 0;
496 			}
497 
498 			/*
499 			 * A new logical device. Scan for end of
500 			 * resources.
501 			 */
502 			bcopy(resinfo, &logical_id, 4);
503 			pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
504 			dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
505 			if (desc)
506 				device_set_desc_copy(dev, desc);
507 			else
508 				device_set_desc_copy(dev,
509 				    pnp_eisaformat(logical_id));
510 			isa_set_vendorid(dev, p->vendor_id);
511 			isa_set_serial(dev, p->serial);
512 			isa_set_logicalid(dev, logical_id);
513 			isa_set_configattr(dev,
514 			    ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
515 			csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
516 			if (!csnldn) {
517 				device_printf(parent, "out of memory\n");
518 				scanning = 0;
519 				break;
520 			}
521 			csnldn->csn = csn;
522 			csnldn->ldn = ldn;
523 			ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
524 			    csnldn);
525 			ldn++;
526 			startres = resp;
527 			break;
528 
529 		case PNP_TAG_END:
530 			if (!startres) {
531 				device_printf(parent, "malformed resources\n");
532 				scanning = 0;
533 				break;
534 			}
535 			pnp_parse_resources(dev, startres,
536 			    resinfo - startres - 1, ldn);
537 			dev = 0;
538 			startres = 0;
539 			scanning = 0;
540 			break;
541 
542 		default:
543 			/* Skip this resource */
544 			break;
545 		}
546 	}
547 
548 	return (retval);
549 }
550 
551 /*
552  * Read 'amount' bytes of resources from the card, allocating memory
553  * as needed. If a buffer is already available, it should be passed in
554  * '*resourcesp' and its length in '*spacep'. The number of resource
555  * bytes already in the buffer should be passed in '*lenp'. The memory
556  * allocated will be returned in '*resourcesp' with its size and the
557  * number of bytes of resources in '*spacep' and '*lenp' respectively.
558  *
559  * XXX: Multiple problems here, we forget to free() stuff in one
560  * XXX: error return, and in another case we free (*resourcesp) but
561  * XXX: don't tell the caller.
562  */
563 static int
564 pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
565 {
566 	u_char *resources = *resourcesp;
567 	u_char *newres;
568 	int space = *spacep;
569 	int len = *lenp;
570 
571 	if (space == 0) {
572 		space = 1024;
573 		resources = malloc(space, M_TEMP, M_NOWAIT);
574 		if (!resources)
575 			return (ENOMEM);
576 	}
577 
578 	if (len + amount > space) {
579 		int extra = 1024;
580 		while (len + amount > space + extra)
581 			extra += 1024;
582 		newres = malloc(space + extra, M_TEMP, M_NOWAIT);
583 		if (!newres) {
584 			/* XXX: free resources */
585 			return (ENOMEM);
586 		}
587 		bcopy(resources, newres, len);
588 		free(resources, M_TEMP);
589 		resources = newres;
590 		space += extra;
591 	}
592 
593 	if (pnp_get_resource_info(resources + len, amount) != amount)
594 		return (EINVAL);
595 	len += amount;
596 
597 	*resourcesp = resources;
598 	*spacep = space;
599 	*lenp = len;
600 
601 	return (0);
602 }
603 
604 /*
605  * Read all resources from the card, allocating memory as needed. If a
606  * buffer is already available, it should be passed in '*resourcesp'
607  * and its length in '*spacep'. The memory allocated will be returned
608  * in '*resourcesp' with its size and the number of bytes of resources
609  * in '*spacep' and '*lenp' respectively.
610  */
611 static int
612 pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
613 {
614 	u_char *resources = *resourcesp;
615 	int space = *spacep;
616 	int len = 0;
617 	int error, done;
618 	u_char tag;
619 
620 	error = 0;
621 	done = 0;
622 	while (!done) {
623 		error = pnp_read_bytes(1, &resources, &space, &len);
624 		if (error)
625 			goto out;
626 		tag = resources[len-1];
627 		if (PNP_RES_TYPE(tag) == 0) {
628 			/*
629 			 * Small resource, read contents.
630 			 */
631 			error = pnp_read_bytes(PNP_SRES_LEN(tag),
632 			    &resources, &space, &len);
633 			if (error)
634 				goto out;
635 			if (PNP_SRES_NUM(tag) == PNP_TAG_END)
636 				done = 1;
637 		} else {
638 			/*
639 			 * Large resource, read length and contents.
640 			 */
641 			error = pnp_read_bytes(2, &resources, &space, &len);
642 			if (error)
643 				goto out;
644 			error = pnp_read_bytes(resources[len-2]
645 			    + (resources[len-1] << 8), &resources, &space,
646 			    &len);
647 			if (error)
648 				goto out;
649 		}
650 	}
651 
652  out:
653 	*resourcesp = resources;
654 	*spacep = space;
655 	*lenp = len;
656 	return (error);
657 }
658 
659 /*
660  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
661  * value (caller should try multiple READ_DATA locations before giving
662  * up). Upon exiting, all cards are aware that they should use
663  * pnp_rd_port as the READ_DATA port.
664  *
665  * In the first pass, a csn is assigned to each board and pnp_id's
666  * are saved to an array, pnp_devices. In the second pass, each
667  * card is woken up and the device configuration is called.
668  */
669 static int
670 pnp_isolation_protocol(device_t parent)
671 {
672 	int csn;
673 	pnp_id id;
674 	int found = 0, len;
675 	u_char *resources = 0;
676 	int space = 0;
677 	int error;
678 #ifdef PC98
679 	int n, necpnp;
680 	u_char buffer[10];
681 #endif
682 
683 	/*
684 	 * Put all cards into the Sleep state so that we can clear
685 	 * their CSNs.
686 	 */
687 	pnp_send_initiation_key();
688 
689 	/*
690 	 * Clear the CSN for all cards.
691 	 */
692 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
693 
694 	/*
695 	 * Move all cards to the Isolation state.
696 	 */
697 	pnp_write(PNP_WAKE, 0);
698 
699 	/*
700 	 * Tell them where the read point is going to be this time.
701 	 */
702 	pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
703 
704 	for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
705 		/*
706 		 * Start the serial isolation protocol.
707 		 */
708 		outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
709 		DELAY(1000);	/* Delay 1 msec */
710 
711 		if (pnp_get_serial(&id)) {
712 			/*
713 			 * We have read the id from a card
714 			 * successfully. The card which won the
715 			 * isolation protocol will be in Isolation
716 			 * mode and all others will be in Sleep.
717 			 * Program the CSN of the isolated card
718 			 * (taking it to Config state) and read its
719 			 * resources, creating devices as we find
720 			 * logical devices on the card.
721 			 */
722 			pnp_write(PNP_SET_CSN, csn);
723 #ifdef PC98
724 			if (bootverbose)
725 				printf("PnP Vendor ID = %x\n", id.vendor_id);
726 			/* Check for NEC PnP (9 bytes serial). */
727 			for (n = necpnp = 0; necids[n].vendor_id; n++) {
728 				if (id.vendor_id == necids[n].vendor_id) {
729 					necpnp = 1;
730 					break;
731 				}
732 			}
733 			if (necpnp) {
734 				if (bootverbose)
735 					printf("An NEC-PnP card (%s).\n",
736 					    pnp_eisaformat(id.vendor_id));
737 				/*  Read dummy 9 bytes serial area. */
738 				pnp_get_resource_info(buffer, 9);
739 			} else {
740 				if (bootverbose)
741 					printf("A Normal-ISA-PnP card (%s).\n",
742 					    pnp_eisaformat(id.vendor_id));
743 			}
744 			if (bootverbose)
745 				printf("Reading PnP configuration for %s.\n",
746 				    pnp_eisaformat(id.vendor_id));
747 #endif
748 			error = pnp_read_resources(&resources, &space, &len);
749 			if (error)
750 				break;
751 			pnp_create_devices(parent, &id, csn, resources, len);
752 			found++;
753 		} else
754 			break;
755 
756 		/*
757 		 * Put this card back to the Sleep state and
758 		 * simultaneously move all cards which don't have a
759 		 * CSN yet to Isolation state.
760 		 */
761 		pnp_write(PNP_WAKE, 0);
762 	}
763 
764 	/*
765 	 * Unless we have chosen the wrong read port, all cards will
766 	 * be in Sleep state. Put them back into WaitForKey for
767 	 * now. Their resources will be programmed later.
768 	 */
769 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
770 
771 	/*
772 	 * Cleanup.
773 	 */
774 	if (resources)
775 		free(resources, M_TEMP);
776 
777 	return (found);
778 }
779 
780 
781 /*
782  * pnp_identify()
783  *
784  * autoconfiguration of pnp devices. This routine just runs the
785  * isolation protocol over several ports, until one is successful.
786  *
787  * may be called more than once ?
788  *
789  */
790 
791 static void
792 pnp_identify(driver_t *driver, device_t parent)
793 {
794 	int num_pnp_devs;
795 
796 	/* Try various READ_DATA ports from 0x203-0x3ff */
797 	for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
798 		if (bootverbose)
799 			printf("pnp_identify: Trying Read_Port at %x\n",
800 			    (pnp_rd_port << 2) | 0x3);
801 
802 		num_pnp_devs = pnp_isolation_protocol(parent);
803 		if (num_pnp_devs)
804 			break;
805 	}
806 	if (bootverbose)
807 		printf("PNP Identify complete\n");
808 }
809 
810 static device_method_t pnp_methods[] = {
811 	/* Device interface */
812 	DEVMETHOD(device_identify,	pnp_identify),
813 
814 	{ 0, 0 }
815 };
816 
817 static driver_t pnp_driver = {
818 	"pnp",
819 	pnp_methods,
820 	1,			/* no softc */
821 };
822 
823 static devclass_t pnp_devclass;
824 
825 DRIVER_MODULE(pnp, isa, pnp_driver, pnp_devclass, 0, 0);
826