xref: /freebsd/sys/isa/pnp.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1996, Sujal M. Patel
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *      from: pnp.c,v 1.11 1999/05/06 22:11:19 peter Exp
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/bus.h>
39 #include <sys/endian.h>
40 #include <sys/malloc.h>
41 #include <isa/isavar.h>
42 #include <isa/pnpreg.h>
43 #include <isa/pnpvar.h>
44 #include <machine/bus.h>
45 
46 typedef struct _pnp_id {
47 	uint32_t vendor_id;
48 	uint32_t serial;
49 	u_char checksum;
50 } pnp_id;
51 
52 struct pnp_set_config_arg {
53 	int	csn;		/* Card number to configure */
54 	int	ldn;		/* Logical device on card */
55 };
56 
57 struct pnp_quirk {
58 	uint32_t vendor_id;	/* Vendor of the card */
59 	uint32_t logical_id;	/* ID of the device with quirk */
60 	int	type;
61 #define PNP_QUIRK_WRITE_REG	1 /* Need to write a pnp register  */
62 #define PNP_QUIRK_EXTRA_IO	2 /* Has extra io ports  */
63 	int	arg1;
64 	int	arg2;
65 };
66 
67 struct pnp_quirk pnp_quirks[] = {
68 	/*
69 	 * The Gravis UltraSound needs register 0xf2 to be set to 0xff
70 	 * to enable power.
71 	 * XXX need to know the logical device id.
72 	 */
73 	{ 0x0100561e /* GRV0001 */,	0,
74 	  PNP_QUIRK_WRITE_REG,	0xf2,	 0xff },
75 	/*
76 	 * An emu8000 does not give us other than the first
77 	 * port.
78 	 */
79 	{ 0x26008c0e /* SB16 */,	0x21008c0e,
80 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
81 	{ 0x42008c0e /* SB32(CTL0042) */,	0x21008c0e,
82 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
83 	{ 0x44008c0e /* SB32(CTL0044) */,	0x21008c0e,
84 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
85 	{ 0x49008c0e /* SB32(CTL0049) */,	0x21008c0e,
86 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
87 	{ 0xf1008c0e /* SB32(CTL00f1) */,	0x21008c0e,
88 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
89 	{ 0xc1008c0e /* SB64(CTL00c1) */,	0x22008c0e,
90 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
91 	{ 0xc5008c0e /* SB64(CTL00c5) */,	0x22008c0e,
92 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
93 	{ 0xe4008c0e /* SB64(CTL00e4) */,	0x22008c0e,
94 	  PNP_QUIRK_EXTRA_IO,	0x400,	 0x800 },
95 
96 	{ 0 }
97 };
98 
99 /* The READ_DATA port that we are using currently */
100 static int pnp_rd_port;
101 
102 static void   pnp_send_initiation_key(void);
103 static int    pnp_get_serial(pnp_id *p);
104 static int    pnp_isolation_protocol(device_t parent);
105 
106 static void
107 pnp_write(int d, u_char r)
108 {
109 	outb (_PNP_ADDRESS, d);
110 	outb (_PNP_WRITE_DATA, r);
111 }
112 
113 /*
114  * Send Initiation LFSR as described in "Plug and Play ISA Specification",
115  * Intel May 94.
116  */
117 static void
118 pnp_send_initiation_key()
119 {
120 	int cur, i;
121 
122 	/* Reset the LSFR */
123 	outb(_PNP_ADDRESS, 0);
124 	outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
125 
126 	cur = 0x6a;
127 	outb(_PNP_ADDRESS, cur);
128 
129 	for (i = 1; i < 32; i++) {
130 		cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
131 		outb(_PNP_ADDRESS, cur);
132 	}
133 }
134 
135 
136 /*
137  * Get the device's serial number.  Returns 1 if the serial is valid.
138  */
139 static int
140 pnp_get_serial(pnp_id *p)
141 {
142 	int i, bit, valid = 0, sum = 0x6a;
143 	u_char *data = (u_char *)p;
144 
145 	bzero(data, sizeof(char) * 9);
146 	outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
147 	for (i = 0; i < 72; i++) {
148 		bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
149 		DELAY(250);	/* Delay 250 usec */
150 
151 		/* Can't Short Circuit the next evaluation, so 'and' is last */
152 		bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
153 		DELAY(250);	/* Delay 250 usec */
154 
155 		valid = valid || bit;
156 		if (i < 64)
157 			sum = (sum >> 1) |
158 			  (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
159 		data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
160 	}
161 
162 	valid = valid && (data[8] == sum);
163 
164 	return (valid);
165 }
166 
167 /*
168  * Fill's the buffer with resource info from the device.
169  * Returns the number of characters read.
170  */
171 static int
172 pnp_get_resource_info(u_char *buffer, int len)
173 {
174 	int i, j, count;
175 	u_char temp;
176 
177 	count = 0;
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(10);
184 		}
185 		if (j == 100) {
186 			printf("PnP device failed to report resource data\n");
187 			return (count);
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 		count++;
194 	}
195 	return (count);
196 }
197 
198 /*
199  * This function is called after the bus has assigned resource
200  * locations for a logical device.
201  */
202 static void
203 pnp_set_config(void *arg, struct isa_config *config, int enable)
204 {
205 	int csn = ((struct pnp_set_config_arg *) arg)->csn;
206 	int ldn = ((struct pnp_set_config_arg *) arg)->ldn;
207 	int i;
208 
209 	/*
210 	 * First put all cards into Sleep state with the initiation
211 	 * key, then put our card into Config state.
212 	 */
213 	pnp_send_initiation_key();
214 	pnp_write(PNP_WAKE, csn);
215 
216 	/*
217 	 * Select our logical device so that we can program it.
218 	 */
219 	pnp_write(PNP_SET_LDN, ldn);
220 
221 	/*
222 	 * Constrain the number of resources we will try to program
223 	 */
224 	if (config->ic_nmem > ISA_PNP_NMEM) {
225 		printf("too many ISA memory ranges (%d > %d)\n",
226 		    config->ic_nmem, ISA_PNP_NMEM);
227 		config->ic_nmem = ISA_PNP_NMEM;
228 	}
229 	if (config->ic_nport > ISA_PNP_NPORT) {
230 		printf("too many ISA I/O ranges (%d > %d)\n", config->ic_nport,
231 		    ISA_PNP_NPORT);
232 		config->ic_nport = ISA_PNP_NPORT;
233 	}
234 	if (config->ic_nirq > ISA_PNP_NIRQ) {
235 		printf("too many ISA IRQs (%d > %d)\n", config->ic_nirq,
236 		    ISA_PNP_NIRQ);
237 		config->ic_nirq = ISA_PNP_NIRQ;
238 	}
239 	if (config->ic_ndrq > ISA_PNP_NDRQ) {
240 		printf("too many ISA DRQs (%d > %d)\n", config->ic_ndrq,
241 		    ISA_PNP_NDRQ);
242 		config->ic_ndrq = ISA_PNP_NDRQ;
243 	}
244 
245 	/*
246 	 * Now program the resources.
247 	 */
248 	for (i = 0; i < config->ic_nmem; i++) {
249 		uint32_t start;
250 		uint32_t size;
251 
252 		/* XXX: should handle memory control register, 32 bit memory */
253 		if (config->ic_mem[i].ir_size == 0) {
254 			pnp_write(PNP_MEM_BASE_HIGH(i), 0);
255 			pnp_write(PNP_MEM_BASE_LOW(i), 0);
256 			pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
257 			pnp_write(PNP_MEM_RANGE_LOW(i), 0);
258 		} else {
259 			start = config->ic_mem[i].ir_start;
260 			size =  config->ic_mem[i].ir_size;
261 			if (start & 0xff)
262 				panic("pnp_set_config: bogus memory assignment");
263 			pnp_write(PNP_MEM_BASE_HIGH(i), (start >> 16) & 0xff);
264 			pnp_write(PNP_MEM_BASE_LOW(i), (start >> 8) & 0xff);
265 			pnp_write(PNP_MEM_RANGE_HIGH(i), (size >> 16) & 0xff);
266 			pnp_write(PNP_MEM_RANGE_LOW(i), (size >> 8) & 0xff);
267 		}
268 	}
269 	for (; i < ISA_PNP_NMEM; i++) {
270 		pnp_write(PNP_MEM_BASE_HIGH(i), 0);
271 		pnp_write(PNP_MEM_BASE_LOW(i), 0);
272 		pnp_write(PNP_MEM_RANGE_HIGH(i), 0);
273 		pnp_write(PNP_MEM_RANGE_LOW(i), 0);
274 	}
275 
276 	for (i = 0; i < config->ic_nport; i++) {
277 		uint32_t start;
278 
279 		if (config->ic_port[i].ir_size == 0) {
280 			pnp_write(PNP_IO_BASE_HIGH(i), 0);
281 			pnp_write(PNP_IO_BASE_LOW(i), 0);
282 		} else {
283 			start = config->ic_port[i].ir_start;
284 			pnp_write(PNP_IO_BASE_HIGH(i), (start >> 8) & 0xff);
285 			pnp_write(PNP_IO_BASE_LOW(i), (start >> 0) & 0xff);
286 		}
287 	}
288 	for (; i < ISA_PNP_NPORT; i++) {
289 		pnp_write(PNP_IO_BASE_HIGH(i), 0);
290 		pnp_write(PNP_IO_BASE_LOW(i), 0);
291 	}
292 
293 	for (i = 0; i < config->ic_nirq; i++) {
294 		int irq;
295 
296 		/* XXX: interrupt type */
297 		if (config->ic_irqmask[i] == 0) {
298 			pnp_write(PNP_IRQ_LEVEL(i), 0);
299 			pnp_write(PNP_IRQ_TYPE(i), 2);
300 		} else {
301 			irq = ffs(config->ic_irqmask[i]) - 1;
302 			pnp_write(PNP_IRQ_LEVEL(i), irq);
303 			pnp_write(PNP_IRQ_TYPE(i), 2); /* XXX */
304 		}
305 	}
306 	for (; i < ISA_PNP_NIRQ; i++) {
307 		/*
308 		 * IRQ 0 is not a valid interrupt selection and
309 		 * represents no interrupt selection.
310 		 */
311 		pnp_write(PNP_IRQ_LEVEL(i), 0);
312 		pnp_write(PNP_IRQ_TYPE(i), 2);
313 	}
314 
315 	for (i = 0; i < config->ic_ndrq; i++) {
316 		int drq;
317 
318 		if (config->ic_drqmask[i] == 0) {
319 			pnp_write(PNP_DMA_CHANNEL(i), 4);
320 		} else {
321 			drq = ffs(config->ic_drqmask[i]) - 1;
322 			pnp_write(PNP_DMA_CHANNEL(i), drq);
323 		}
324 	}
325 	for (; i < ISA_PNP_NDRQ; i++) {
326 		/*
327 		 * DMA channel 4, the cascade channel is used to
328 		 * indicate no DMA channel is active.
329 		 */
330 		pnp_write(PNP_DMA_CHANNEL(i), 4);
331 	}
332 
333 	pnp_write(PNP_ACTIVATE, enable ? 1 : 0);
334 
335 	/*
336 	 * Wake everyone up again, we are finished.
337 	 */
338 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
339 }
340 
341 /*
342  * Process quirks for a logical device.. The card must be in Config state.
343  */
344 void
345 pnp_check_quirks(uint32_t vendor_id, uint32_t logical_id, int ldn,
346     struct isa_config *config)
347 {
348 	struct pnp_quirk *qp;
349 
350 	for (qp = &pnp_quirks[0]; qp->vendor_id; qp++) {
351 		if (qp->vendor_id == vendor_id
352 		    && (qp->logical_id == 0 || qp->logical_id == logical_id)) {
353 			switch (qp->type) {
354 			case PNP_QUIRK_WRITE_REG:
355 				pnp_write(PNP_SET_LDN, ldn);
356 				pnp_write(qp->arg1, qp->arg2);
357 				break;
358 			case PNP_QUIRK_EXTRA_IO:
359 				if (config == NULL)
360 					break;
361 				if (qp->arg1 != 0) {
362 					config->ic_nport++;
363 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
364 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg1;
365 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg1;
366 				}
367 				if (qp->arg2 != 0) {
368 					config->ic_nport++;
369 					config->ic_port[config->ic_nport - 1] = config->ic_port[0];
370 					config->ic_port[config->ic_nport - 1].ir_start += qp->arg2;
371 					config->ic_port[config->ic_nport - 1].ir_end += qp->arg2;
372 				}
373 				break;
374 			}
375 		}
376 	}
377 }
378 
379 /*
380  * Scan Resource Data for Logical Devices.
381  *
382  * This function exits as soon as it gets an error reading *ANY*
383  * Resource Data or it reaches the end of Resource Data.  In the first
384  * case the return value will be TRUE, FALSE otherwise.
385  */
386 static int
387 pnp_create_devices(device_t parent, pnp_id *p, int csn,
388     u_char *resources, int len)
389 {
390 	u_char tag, *resp, *resinfo, *startres = NULL;
391 	int large_len, scanning = len, retval = FALSE;
392 	uint32_t logical_id;
393 	device_t dev = 0;
394 	int ldn = 0;
395 	struct pnp_set_config_arg *csnldn;
396 	char buf[100];
397 	char *desc = NULL;
398 
399 	resp = resources;
400 	while (scanning > 0) {
401 		tag = *resp++;
402 		scanning--;
403 		if (PNP_RES_TYPE(tag) != 0) {
404 			/* Large resource */
405 			if (scanning < 2) {
406 				scanning = 0;
407 				continue;
408 			}
409 			large_len = resp[0] + (resp[1] << 8);
410 			resp += 2;
411 
412 			if (scanning < large_len) {
413 				scanning = 0;
414 				continue;
415 			}
416 			resinfo = resp;
417 			resp += large_len;
418 			scanning -= large_len;
419 
420 			if (PNP_LRES_NUM(tag) == PNP_TAG_ID_ANSI) {
421 				if (dev) {
422 					/*
423 					 * This is an optional device
424 					 * identifier string. Skip it
425 					 * for now.
426 					 */
427 					continue;
428 				}
429 				/* else mandately card identifier string */
430 				if (large_len > sizeof(buf) - 1)
431 					large_len = sizeof(buf) - 1;
432 				bcopy(resinfo, buf, large_len);
433 
434 				/*
435 				 * Trim trailing spaces.
436 				 */
437 				while (buf[large_len-1] == ' ')
438 					large_len--;
439 				buf[large_len] = '\0';
440 				desc = buf;
441 				continue;
442 			}
443 
444 			continue;
445 		}
446 
447 		/* Small resource */
448 		if (scanning < PNP_SRES_LEN(tag)) {
449 			scanning = 0;
450 			continue;
451 		}
452 		resinfo = resp;
453 		resp += PNP_SRES_LEN(tag);
454 		scanning -= PNP_SRES_LEN(tag);
455 
456 		switch (PNP_SRES_NUM(tag)) {
457 		case PNP_TAG_LOGICAL_DEVICE:
458 			/*
459 			 * Parse the resources for the previous
460 			 * logical device (if any).
461 			 */
462 			if (startres) {
463 				pnp_parse_resources(dev, startres,
464 				    resinfo - startres - 1, ldn);
465 				dev = 0;
466 				startres = NULL;
467 			}
468 
469 			/*
470 			 * A new logical device. Scan for end of
471 			 * resources.
472 			 */
473 			bcopy(resinfo, &logical_id, 4);
474 			pnp_check_quirks(p->vendor_id, logical_id, ldn, NULL);
475 			dev = BUS_ADD_CHILD(parent, ISA_ORDER_PNP, NULL, -1);
476 			if (desc)
477 				device_set_desc_copy(dev, desc);
478 			else
479 				device_set_desc_copy(dev,
480 				    pnp_eisaformat(logical_id));
481 			isa_set_vendorid(dev, p->vendor_id);
482 			isa_set_serial(dev, p->serial);
483 			isa_set_logicalid(dev, logical_id);
484 			isa_set_configattr(dev,
485 			    ISACFGATTR_CANDISABLE | ISACFGATTR_DYNAMIC);
486 			csnldn = malloc(sizeof *csnldn, M_DEVBUF, M_NOWAIT);
487 			if (!csnldn) {
488 				device_printf(parent, "out of memory\n");
489 				scanning = 0;
490 				break;
491 			}
492 			csnldn->csn = csn;
493 			csnldn->ldn = ldn;
494 			ISA_SET_CONFIG_CALLBACK(parent, dev, pnp_set_config,
495 			    csnldn);
496 			isa_set_pnp_csn(dev, csn);
497 			isa_set_pnp_ldn(dev, ldn);
498 			ldn++;
499 			startres = resp;
500 			break;
501 
502 		case PNP_TAG_END:
503 			if (!startres) {
504 				device_printf(parent, "malformed resources\n");
505 				scanning = 0;
506 				break;
507 			}
508 			pnp_parse_resources(dev, startres,
509 			    resinfo - startres - 1, ldn);
510 			dev = 0;
511 			startres = NULL;
512 			scanning = 0;
513 			break;
514 
515 		default:
516 			/* Skip this resource */
517 			break;
518 		}
519 	}
520 
521 	return (retval);
522 }
523 
524 /*
525  * Read 'amount' bytes of resources from the card, allocating memory
526  * as needed. If a buffer is already available, it should be passed in
527  * '*resourcesp' and its length in '*spacep'. The number of resource
528  * bytes already in the buffer should be passed in '*lenp'. The memory
529  * allocated will be returned in '*resourcesp' with its size and the
530  * number of bytes of resources in '*spacep' and '*lenp' respectively.
531  *
532  * XXX: Multiple problems here, we forget to free() stuff in one
533  * XXX: error return, and in another case we free (*resourcesp) but
534  * XXX: don't tell the caller.
535  */
536 static int
537 pnp_read_bytes(int amount, u_char **resourcesp, int *spacep, int *lenp)
538 {
539 	u_char *resources = *resourcesp;
540 	u_char *newres;
541 	int space = *spacep;
542 	int len = *lenp;
543 
544 	if (space == 0) {
545 		space = 1024;
546 		resources = malloc(space, M_TEMP, M_NOWAIT);
547 		if (!resources)
548 			return (ENOMEM);
549 	}
550 
551 	if (len + amount > space) {
552 		int extra = 1024;
553 		while (len + amount > space + extra)
554 			extra += 1024;
555 		newres = malloc(space + extra, M_TEMP, M_NOWAIT);
556 		if (!newres) {
557 			/* XXX: free resources */
558 			return (ENOMEM);
559 		}
560 		bcopy(resources, newres, len);
561 		free(resources, M_TEMP);
562 		resources = newres;
563 		space += extra;
564 	}
565 
566 	if (pnp_get_resource_info(resources + len, amount) != amount)
567 		return (EINVAL);
568 	len += amount;
569 
570 	*resourcesp = resources;
571 	*spacep = space;
572 	*lenp = len;
573 
574 	return (0);
575 }
576 
577 /*
578  * Read all resources from the card, allocating memory as needed. If a
579  * buffer is already available, it should be passed in '*resourcesp'
580  * and its length in '*spacep'. The memory allocated will be returned
581  * in '*resourcesp' with its size and the number of bytes of resources
582  * in '*spacep' and '*lenp' respectively.
583  */
584 static int
585 pnp_read_resources(u_char **resourcesp, int *spacep, int *lenp)
586 {
587 	u_char *resources = *resourcesp;
588 	int space = *spacep;
589 	int len = 0;
590 	int error, done;
591 	u_char tag;
592 
593 	error = 0;
594 	done = 0;
595 	while (!done) {
596 		error = pnp_read_bytes(1, &resources, &space, &len);
597 		if (error)
598 			goto out;
599 		tag = resources[len-1];
600 		if (PNP_RES_TYPE(tag) == 0) {
601 			/*
602 			 * Small resource, read contents.
603 			 */
604 			error = pnp_read_bytes(PNP_SRES_LEN(tag),
605 			    &resources, &space, &len);
606 			if (error)
607 				goto out;
608 			if (PNP_SRES_NUM(tag) == PNP_TAG_END)
609 				done = 1;
610 		} else {
611 			/*
612 			 * Large resource, read length and contents.
613 			 */
614 			error = pnp_read_bytes(2, &resources, &space, &len);
615 			if (error)
616 				goto out;
617 			error = pnp_read_bytes(resources[len-2]
618 			    + (resources[len-1] << 8), &resources, &space,
619 			    &len);
620 			if (error)
621 				goto out;
622 		}
623 	}
624 
625  out:
626 	*resourcesp = resources;
627 	*spacep = space;
628 	*lenp = len;
629 	return (error);
630 }
631 
632 /*
633  * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
634  * value (caller should try multiple READ_DATA locations before giving
635  * up). Upon exiting, all cards are aware that they should use
636  * pnp_rd_port as the READ_DATA port.
637  *
638  * In the first pass, a csn is assigned to each board and pnp_id's
639  * are saved to an array, pnp_devices. In the second pass, each
640  * card is woken up and the device configuration is called.
641  */
642 static int
643 pnp_isolation_protocol(device_t parent)
644 {
645 	int csn;
646 	pnp_id id;
647 	int found = 0, len;
648 	u_char *resources = NULL;
649 	int space = 0;
650 	int error;
651 
652 	/*
653 	 * Put all cards into the Sleep state so that we can clear
654 	 * their CSNs.
655 	 */
656 	pnp_send_initiation_key();
657 
658 	/*
659 	 * Clear the CSN for all cards.
660 	 */
661 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_RESET_CSN);
662 
663 	/*
664 	 * Move all cards to the Isolation state.
665 	 */
666 	pnp_write(PNP_WAKE, 0);
667 
668 	/*
669 	 * Tell them where the read point is going to be this time.
670 	 */
671 	pnp_write(PNP_SET_RD_DATA, pnp_rd_port);
672 
673 	for (csn = 1; csn < PNP_MAX_CARDS; csn++) {
674 		/*
675 		 * Start the serial isolation protocol.
676 		 */
677 		outb(_PNP_ADDRESS, PNP_SERIAL_ISOLATION);
678 		DELAY(1000);	/* Delay 1 msec */
679 
680 		if (pnp_get_serial(&id)) {
681 			/*
682 			 * We have read the id from a card
683 			 * successfully. The card which won the
684 			 * isolation protocol will be in Isolation
685 			 * mode and all others will be in Sleep.
686 			 * Program the CSN of the isolated card
687 			 * (taking it to Config state) and read its
688 			 * resources, creating devices as we find
689 			 * logical devices on the card.
690 			 */
691 			pnp_write(PNP_SET_CSN, csn);
692 			if (bootverbose)
693 				printf("Reading PnP configuration for %s.\n",
694 				    pnp_eisaformat(id.vendor_id));
695 			error = pnp_read_resources(&resources, &space, &len);
696 			if (error)
697 				break;
698 			pnp_create_devices(parent, &id, csn, resources, len);
699 			found++;
700 		} else
701 			break;
702 
703 		/*
704 		 * Put this card back to the Sleep state and
705 		 * simultaneously move all cards which don't have a
706 		 * CSN yet to Isolation state.
707 		 */
708 		pnp_write(PNP_WAKE, 0);
709 	}
710 
711 	/*
712 	 * Unless we have chosen the wrong read port, all cards will
713 	 * be in Sleep state. Put them back into WaitForKey for
714 	 * now. Their resources will be programmed later.
715 	 */
716 	pnp_write(PNP_CONFIG_CONTROL, PNP_CONFIG_CONTROL_WAIT_FOR_KEY);
717 
718 	/*
719 	 * Cleanup.
720 	 */
721 	if (resources)
722 		free(resources, M_TEMP);
723 
724 	return (found);
725 }
726 
727 
728 /*
729  * pnp_identify()
730  *
731  * autoconfiguration of pnp devices. This routine just runs the
732  * isolation protocol over several ports, until one is successful.
733  *
734  * may be called more than once ?
735  *
736  */
737 
738 static void
739 pnp_identify(driver_t *driver, device_t parent)
740 {
741 	int num_pnp_devs;
742 
743 	/* Try various READ_DATA ports from 0x203-0x3ff */
744 	for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
745 		if (bootverbose)
746 			printf("pnp_identify: Trying Read_Port at %x\n",
747 			    (pnp_rd_port << 2) | 0x3);
748 
749 		num_pnp_devs = pnp_isolation_protocol(parent);
750 		if (num_pnp_devs)
751 			break;
752 	}
753 	if (bootverbose)
754 		printf("PNP Identify complete\n");
755 }
756 
757 static device_method_t pnp_methods[] = {
758 	/* Device interface */
759 	DEVMETHOD(device_identify,	pnp_identify),
760 
761 	{ 0, 0 }
762 };
763 
764 static driver_t pnp_driver = {
765 	"pnp",
766 	pnp_methods,
767 	1,			/* no softc */
768 };
769 
770 static devclass_t pnp_devclass;
771 
772 DRIVER_MODULE(pnp, isa, pnp_driver, pnp_devclass, 0, 0);
773