xref: /linux/drivers/pnp/isapnp/core.c (revision 7b347ad4938ddca1a22b983e36b9ef825a72d230)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ISA Plug & Play support
4  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5  *
6  *  Changelog:
7  *  2000-01-01	Added quirks handling for buggy hardware
8  *		Peter Denison <peterd@pnd-pc.demon.co.uk>
9  *  2000-06-14	Added isapnp_probe_devs() and isapnp_activate_dev()
10  *		Christoph Hellwig <hch@infradead.org>
11  *  2001-06-03  Added release_region calls to correspond with
12  *		request_region calls when a failure occurs.  Also
13  *		added KERN_* constants to printk() calls.
14  *  2001-11-07  Added isapnp_{,un}register_driver calls along the lines
15  *              of the pci driver interface
16  *              Kai Germaschewski <kai.germaschewski@gmx.de>
17  *  2002-06-06  Made the use of dma channel 0 configurable
18  *              Gerald Teschl <gerald.teschl@univie.ac.at>
19  *  2002-10-06  Ported to PnP Layer - Adam Belay <ambx1@neo.rr.com>
20  *  2003-08-11	Resource Management Updates - Adam Belay <ambx1@neo.rr.com>
21  */
22 
23 #include <linux/moduleparam.h>
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/delay.h>
27 #include <linux/init.h>
28 #include <linux/isapnp.h>
29 #include <linux/mutex.h>
30 #include <asm/io.h>
31 
32 #include "../base.h"
33 
34 #if 0
35 #define ISAPNP_REGION_OK
36 #endif
37 
38 int isapnp_disable;		/* Disable ISA PnP */
39 static int isapnp_rdp;		/* Read Data Port */
40 static int isapnp_reset = 1;	/* reset all PnP cards (deactivate) */
41 static int isapnp_verbose = 1;	/* verbose mode */
42 
43 module_param(isapnp_disable, int, 0);
44 MODULE_PARM_DESC(isapnp_disable, "ISA Plug & Play disable");
45 module_param(isapnp_rdp, int, 0);
46 MODULE_PARM_DESC(isapnp_rdp, "ISA Plug & Play read data port");
47 module_param(isapnp_reset, int, 0);
48 MODULE_PARM_DESC(isapnp_reset, "ISA Plug & Play reset all cards");
49 module_param(isapnp_verbose, int, 0);
50 MODULE_PARM_DESC(isapnp_verbose, "ISA Plug & Play verbose mode");
51 
52 #define _PIDXR		0x279
53 #define _PNPWRP		0xa79
54 
55 /* short tags */
56 #define _STAG_PNPVERNO		0x01
57 #define _STAG_LOGDEVID		0x02
58 #define _STAG_COMPATDEVID	0x03
59 #define _STAG_IRQ		0x04
60 #define _STAG_DMA		0x05
61 #define _STAG_STARTDEP		0x06
62 #define _STAG_ENDDEP		0x07
63 #define _STAG_IOPORT		0x08
64 #define _STAG_FIXEDIO		0x09
65 #define _STAG_VENDOR		0x0e
66 #define _STAG_END		0x0f
67 /* long tags */
68 #define _LTAG_MEMRANGE		0x81
69 #define _LTAG_ANSISTR		0x82
70 #define _LTAG_UNICODESTR	0x83
71 #define _LTAG_VENDOR		0x84
72 #define _LTAG_MEM32RANGE	0x85
73 #define _LTAG_FIXEDMEM32RANGE	0x86
74 
75 /* Logical device control and configuration registers */
76 
77 #define ISAPNP_CFG_ACTIVATE	0x30	/* byte */
78 #define ISAPNP_CFG_MEM		0x40	/* 4 * dword */
79 #define ISAPNP_CFG_PORT		0x60	/* 8 * word */
80 #define ISAPNP_CFG_IRQ		0x70	/* 2 * word */
81 #define ISAPNP_CFG_DMA		0x74	/* 2 * byte */
82 
83 /*
84  * Sizes of ISAPNP logical device configuration register sets.
85  * See PNP-ISA-v1.0a.pdf, Appendix A.
86  */
87 #define ISAPNP_MAX_MEM		4
88 #define ISAPNP_MAX_PORT		8
89 #define ISAPNP_MAX_IRQ		2
90 #define ISAPNP_MAX_DMA		2
91 
92 static unsigned char isapnp_checksum_value;
93 static DEFINE_MUTEX(isapnp_cfg_mutex);
94 static int isapnp_csn_count;
95 
96 /* some prototypes */
97 
98 static inline void write_data(unsigned char x)
99 {
100 	outb(x, _PNPWRP);
101 }
102 
103 static inline void write_address(unsigned char x)
104 {
105 	outb(x, _PIDXR);
106 	udelay(20);
107 }
108 
109 static inline unsigned char read_data(void)
110 {
111 	unsigned char val = inb(isapnp_rdp);
112 	return val;
113 }
114 
115 unsigned char isapnp_read_byte(unsigned char idx)
116 {
117 	write_address(idx);
118 	return read_data();
119 }
120 
121 static unsigned short isapnp_read_word(unsigned char idx)
122 {
123 	unsigned short val;
124 
125 	val = isapnp_read_byte(idx);
126 	val = (val << 8) + isapnp_read_byte(idx + 1);
127 	return val;
128 }
129 
130 void isapnp_write_byte(unsigned char idx, unsigned char val)
131 {
132 	write_address(idx);
133 	write_data(val);
134 }
135 
136 static void isapnp_write_word(unsigned char idx, unsigned short val)
137 {
138 	isapnp_write_byte(idx, val >> 8);
139 	isapnp_write_byte(idx + 1, val);
140 }
141 
142 static void isapnp_key(void)
143 {
144 	unsigned char code = 0x6a, msb;
145 	int i;
146 
147 	mdelay(1);
148 	write_address(0x00);
149 	write_address(0x00);
150 
151 	write_address(code);
152 
153 	for (i = 1; i < 32; i++) {
154 		msb = ((code & 0x01) ^ ((code & 0x02) >> 1)) << 7;
155 		code = (code >> 1) | msb;
156 		write_address(code);
157 	}
158 }
159 
160 /* place all pnp cards in wait-for-key state */
161 static void isapnp_wait(void)
162 {
163 	isapnp_write_byte(0x02, 0x02);
164 }
165 
166 static void isapnp_wake(unsigned char csn)
167 {
168 	isapnp_write_byte(0x03, csn);
169 }
170 
171 static void isapnp_device(unsigned char logdev)
172 {
173 	isapnp_write_byte(0x07, logdev);
174 }
175 
176 static void isapnp_activate(unsigned char logdev)
177 {
178 	isapnp_device(logdev);
179 	isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 1);
180 	udelay(250);
181 }
182 
183 static void isapnp_deactivate(unsigned char logdev)
184 {
185 	isapnp_device(logdev);
186 	isapnp_write_byte(ISAPNP_CFG_ACTIVATE, 0);
187 	udelay(500);
188 }
189 
190 static void __init isapnp_peek(unsigned char *data, int bytes)
191 {
192 	int i, j;
193 	unsigned char d = 0;
194 
195 	for (i = 1; i <= bytes; i++) {
196 		for (j = 0; j < 20; j++) {
197 			d = isapnp_read_byte(0x05);
198 			if (d & 1)
199 				break;
200 			udelay(100);
201 		}
202 		if (!(d & 1)) {
203 			if (data != NULL)
204 				*data++ = 0xff;
205 			continue;
206 		}
207 		d = isapnp_read_byte(0x04);	/* PRESDI */
208 		isapnp_checksum_value += d;
209 		if (data != NULL)
210 			*data++ = d;
211 	}
212 }
213 
214 #define RDP_STEP	32	/* minimum is 4 */
215 
216 static int isapnp_next_rdp(void)
217 {
218 	int rdp = isapnp_rdp;
219 	static int old_rdp = 0;
220 
221 	if (old_rdp) {
222 		release_region(old_rdp, 1);
223 		old_rdp = 0;
224 	}
225 	while (rdp <= 0x3ff) {
226 		/*
227 		 *      We cannot use NE2000 probe spaces for ISAPnP or we
228 		 *      will lock up machines.
229 		 */
230 		if ((rdp < 0x280 || rdp > 0x380)
231 		    && request_region(rdp, 1, "ISAPnP")) {
232 			isapnp_rdp = rdp;
233 			old_rdp = rdp;
234 			return 0;
235 		}
236 		rdp += RDP_STEP;
237 	}
238 	return -1;
239 }
240 
241 /* Set read port address */
242 static inline void isapnp_set_rdp(void)
243 {
244 	isapnp_write_byte(0x00, isapnp_rdp >> 2);
245 	udelay(100);
246 }
247 
248 /*
249  *	Perform an isolation. The port selection code now tries to avoid
250  *	"dangerous to read" ports.
251  */
252 static int __init isapnp_isolate_rdp_select(void)
253 {
254 	isapnp_wait();
255 	isapnp_key();
256 
257 	/* Control: reset CSN and conditionally everything else too */
258 	isapnp_write_byte(0x02, isapnp_reset ? 0x05 : 0x04);
259 	mdelay(2);
260 
261 	isapnp_wait();
262 	isapnp_key();
263 	isapnp_wake(0x00);
264 
265 	if (isapnp_next_rdp() < 0) {
266 		isapnp_wait();
267 		return -1;
268 	}
269 
270 	isapnp_set_rdp();
271 	udelay(1000);
272 	write_address(0x01);
273 	udelay(1000);
274 	return 0;
275 }
276 
277 /*
278  *  Isolate (assign uniqued CSN) to all ISA PnP devices.
279  */
280 static int __init isapnp_isolate(void)
281 {
282 	unsigned char checksum = 0x6a;
283 	unsigned char chksum = 0x00;
284 	unsigned char bit = 0x00;
285 	int data;
286 	int csn = 0;
287 	int i;
288 	int iteration = 1;
289 
290 	isapnp_rdp = 0x213;
291 	if (isapnp_isolate_rdp_select() < 0)
292 		return -1;
293 
294 	while (1) {
295 		for (i = 1; i <= 64; i++) {
296 			data = read_data() << 8;
297 			udelay(250);
298 			data = data | read_data();
299 			udelay(250);
300 			if (data == 0x55aa)
301 				bit = 0x01;
302 			checksum =
303 			    ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
304 			    | (checksum >> 1);
305 			bit = 0x00;
306 		}
307 		for (i = 65; i <= 72; i++) {
308 			data = read_data() << 8;
309 			udelay(250);
310 			data = data | read_data();
311 			udelay(250);
312 			if (data == 0x55aa)
313 				chksum |= (1 << (i - 65));
314 		}
315 		if (checksum != 0x00 && checksum == chksum) {
316 			csn++;
317 
318 			isapnp_write_byte(0x06, csn);
319 			udelay(250);
320 			iteration++;
321 			isapnp_wake(0x00);
322 			isapnp_set_rdp();
323 			udelay(1000);
324 			write_address(0x01);
325 			udelay(1000);
326 			goto __next;
327 		}
328 		if (iteration == 1) {
329 			isapnp_rdp += RDP_STEP;
330 			if (isapnp_isolate_rdp_select() < 0)
331 				return -1;
332 		} else if (iteration > 1) {
333 			break;
334 		}
335 __next:
336 		if (csn == 255)
337 			break;
338 		checksum = 0x6a;
339 		chksum = 0x00;
340 		bit = 0x00;
341 	}
342 	isapnp_wait();
343 	isapnp_csn_count = csn;
344 	return csn;
345 }
346 
347 /*
348  *  Read one tag from stream.
349  */
350 static int __init isapnp_read_tag(unsigned char *type, unsigned short *size)
351 {
352 	unsigned char tag, tmp[2];
353 
354 	isapnp_peek(&tag, 1);
355 	if (tag == 0)		/* invalid tag */
356 		return -1;
357 	if (tag & 0x80) {	/* large item */
358 		*type = tag;
359 		isapnp_peek(tmp, 2);
360 		*size = (tmp[1] << 8) | tmp[0];
361 	} else {
362 		*type = (tag >> 3) & 0x0f;
363 		*size = tag & 0x07;
364 	}
365 	if (*type == 0xff && *size == 0xffff)	/* probably invalid data */
366 		return -1;
367 	return 0;
368 }
369 
370 /*
371  *  Skip specified number of bytes from stream.
372  */
373 static void __init isapnp_skip_bytes(int count)
374 {
375 	isapnp_peek(NULL, count);
376 }
377 
378 /*
379  *  Parse logical device tag.
380  */
381 static struct pnp_dev *__init isapnp_parse_device(struct pnp_card *card,
382 						  int size, int number)
383 {
384 	unsigned char tmp[6];
385 	struct pnp_dev *dev;
386 	u32 eisa_id;
387 	char id[8];
388 
389 	isapnp_peek(tmp, size);
390 	eisa_id = tmp[0] | tmp[1] << 8 | tmp[2] << 16 | tmp[3] << 24;
391 	pnp_eisa_id_to_string(eisa_id, id);
392 
393 	dev = pnp_alloc_dev(&isapnp_protocol, number, id);
394 	if (!dev)
395 		return NULL;
396 
397 	dev->card = card;
398 	dev->capabilities |= PNP_CONFIGURABLE;
399 	dev->capabilities |= PNP_READ;
400 	dev->capabilities |= PNP_WRITE;
401 	dev->capabilities |= PNP_DISABLE;
402 	pnp_init_resources(dev);
403 	return dev;
404 }
405 
406 /*
407  *  Add IRQ resource to resources list.
408  */
409 static void __init isapnp_parse_irq_resource(struct pnp_dev *dev,
410 					     unsigned int option_flags,
411 					     int size)
412 {
413 	unsigned char tmp[3];
414 	unsigned long bits;
415 	pnp_irq_mask_t map;
416 	unsigned char flags = IORESOURCE_IRQ_HIGHEDGE;
417 
418 	isapnp_peek(tmp, size);
419 	bits = (tmp[1] << 8) | tmp[0];
420 
421 	bitmap_zero(map.bits, PNP_IRQ_NR);
422 	bitmap_copy(map.bits, &bits, 16);
423 
424 	if (size > 2)
425 		flags = tmp[2];
426 
427 	pnp_register_irq_resource(dev, option_flags, &map, flags);
428 }
429 
430 /*
431  *  Add DMA resource to resources list.
432  */
433 static void __init isapnp_parse_dma_resource(struct pnp_dev *dev,
434 					     unsigned int option_flags,
435 					     int size)
436 {
437 	unsigned char tmp[2];
438 
439 	isapnp_peek(tmp, size);
440 	pnp_register_dma_resource(dev, option_flags, tmp[0], tmp[1]);
441 }
442 
443 /*
444  *  Add port resource to resources list.
445  */
446 static void __init isapnp_parse_port_resource(struct pnp_dev *dev,
447 					      unsigned int option_flags,
448 					      int size)
449 {
450 	unsigned char tmp[7];
451 	resource_size_t min, max, align, len;
452 	unsigned char flags;
453 
454 	isapnp_peek(tmp, size);
455 	min = (tmp[2] << 8) | tmp[1];
456 	max = (tmp[4] << 8) | tmp[3];
457 	align = tmp[5];
458 	len = tmp[6];
459 	flags = tmp[0] ? IORESOURCE_IO_16BIT_ADDR : 0;
460 	pnp_register_port_resource(dev, option_flags,
461 				   min, max, align, len, flags);
462 }
463 
464 /*
465  *  Add fixed port resource to resources list.
466  */
467 static void __init isapnp_parse_fixed_port_resource(struct pnp_dev *dev,
468 						    unsigned int option_flags,
469 						    int size)
470 {
471 	unsigned char tmp[3];
472 	resource_size_t base, len;
473 
474 	isapnp_peek(tmp, size);
475 	base = (tmp[1] << 8) | tmp[0];
476 	len = tmp[2];
477 	pnp_register_port_resource(dev, option_flags, base, base, 0, len,
478 				   IORESOURCE_IO_FIXED);
479 }
480 
481 /*
482  *  Add memory resource to resources list.
483  */
484 static void __init isapnp_parse_mem_resource(struct pnp_dev *dev,
485 					     unsigned int option_flags,
486 					     int size)
487 {
488 	unsigned char tmp[9];
489 	resource_size_t min, max, align, len;
490 	unsigned char flags;
491 
492 	isapnp_peek(tmp, size);
493 	min = ((tmp[2] << 8) | tmp[1]) << 8;
494 	max = ((tmp[4] << 8) | tmp[3]) << 8;
495 	align = (tmp[6] << 8) | tmp[5];
496 	len = ((tmp[8] << 8) | tmp[7]) << 8;
497 	flags = tmp[0];
498 	pnp_register_mem_resource(dev, option_flags,
499 				  min, max, align, len, flags);
500 }
501 
502 /*
503  *  Add 32-bit memory resource to resources list.
504  */
505 static void __init isapnp_parse_mem32_resource(struct pnp_dev *dev,
506 					       unsigned int option_flags,
507 					       int size)
508 {
509 	unsigned char tmp[17];
510 	resource_size_t min, max, align, len;
511 	unsigned char flags;
512 
513 	isapnp_peek(tmp, size);
514 	min = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
515 	max = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
516 	align = (tmp[12] << 24) | (tmp[11] << 16) | (tmp[10] << 8) | tmp[9];
517 	len = (tmp[16] << 24) | (tmp[15] << 16) | (tmp[14] << 8) | tmp[13];
518 	flags = tmp[0];
519 	pnp_register_mem_resource(dev, option_flags,
520 				  min, max, align, len, flags);
521 }
522 
523 /*
524  *  Add 32-bit fixed memory resource to resources list.
525  */
526 static void __init isapnp_parse_fixed_mem32_resource(struct pnp_dev *dev,
527 						     unsigned int option_flags,
528 						     int size)
529 {
530 	unsigned char tmp[9];
531 	resource_size_t base, len;
532 	unsigned char flags;
533 
534 	isapnp_peek(tmp, size);
535 	base = (tmp[4] << 24) | (tmp[3] << 16) | (tmp[2] << 8) | tmp[1];
536 	len = (tmp[8] << 24) | (tmp[7] << 16) | (tmp[6] << 8) | tmp[5];
537 	flags = tmp[0];
538 	pnp_register_mem_resource(dev, option_flags, base, base, 0, len, flags);
539 }
540 
541 /*
542  *  Parse card name for ISA PnP device.
543  */
544 static void __init
545 isapnp_parse_name(char *name, unsigned int name_max, unsigned short *size)
546 {
547 	if (name[0] == '\0') {
548 		unsigned short size1 =
549 		    *size >= name_max ? (name_max - 1) : *size;
550 		isapnp_peek(name, size1);
551 		name[size1] = '\0';
552 		*size -= size1;
553 
554 		/* clean whitespace from end of string */
555 		while (size1 > 0 && name[--size1] == ' ')
556 			name[size1] = '\0';
557 	}
558 }
559 
560 /*
561  *  Parse resource map for logical device.
562  */
563 static int __init isapnp_create_device(struct pnp_card *card,
564 				       unsigned short size)
565 {
566 	int number = 0, skip = 0, priority, compat = 0;
567 	unsigned char type, tmp[17];
568 	unsigned int option_flags;
569 	struct pnp_dev *dev;
570 	u32 eisa_id;
571 	char id[8];
572 
573 	if ((dev = isapnp_parse_device(card, size, number++)) == NULL)
574 		return 1;
575 	option_flags = 0;
576 	pnp_add_card_device(card, dev);
577 
578 	while (1) {
579 		if (isapnp_read_tag(&type, &size) < 0)
580 			return 1;
581 		if (skip && type != _STAG_LOGDEVID && type != _STAG_END)
582 			goto __skip;
583 		switch (type) {
584 		case _STAG_LOGDEVID:
585 			if (size >= 5 && size <= 6) {
586 				if ((dev =
587 				     isapnp_parse_device(card, size,
588 							 number++)) == NULL)
589 					return 1;
590 				size = 0;
591 				skip = 0;
592 				option_flags = 0;
593 				pnp_add_card_device(card, dev);
594 			} else {
595 				skip = 1;
596 			}
597 			compat = 0;
598 			break;
599 		case _STAG_COMPATDEVID:
600 			if (size == 4 && compat < DEVICE_COUNT_COMPATIBLE) {
601 				isapnp_peek(tmp, 4);
602 				eisa_id = tmp[0] | tmp[1] << 8 |
603 					  tmp[2] << 16 | tmp[3] << 24;
604 				pnp_eisa_id_to_string(eisa_id, id);
605 				pnp_add_id(dev, id);
606 				compat++;
607 				size = 0;
608 			}
609 			break;
610 		case _STAG_IRQ:
611 			if (size < 2 || size > 3)
612 				goto __skip;
613 			isapnp_parse_irq_resource(dev, option_flags, size);
614 			size = 0;
615 			break;
616 		case _STAG_DMA:
617 			if (size != 2)
618 				goto __skip;
619 			isapnp_parse_dma_resource(dev, option_flags, size);
620 			size = 0;
621 			break;
622 		case _STAG_STARTDEP:
623 			if (size > 1)
624 				goto __skip;
625 			priority = PNP_RES_PRIORITY_ACCEPTABLE;
626 			if (size > 0) {
627 				isapnp_peek(tmp, size);
628 				priority = tmp[0];
629 				size = 0;
630 			}
631 			option_flags = pnp_new_dependent_set(dev, priority);
632 			break;
633 		case _STAG_ENDDEP:
634 			if (size != 0)
635 				goto __skip;
636 			option_flags = 0;
637 			break;
638 		case _STAG_IOPORT:
639 			if (size != 7)
640 				goto __skip;
641 			isapnp_parse_port_resource(dev, option_flags, size);
642 			size = 0;
643 			break;
644 		case _STAG_FIXEDIO:
645 			if (size != 3)
646 				goto __skip;
647 			isapnp_parse_fixed_port_resource(dev, option_flags,
648 							 size);
649 			size = 0;
650 			break;
651 		case _STAG_VENDOR:
652 			break;
653 		case _LTAG_MEMRANGE:
654 			if (size != 9)
655 				goto __skip;
656 			isapnp_parse_mem_resource(dev, option_flags, size);
657 			size = 0;
658 			break;
659 		case _LTAG_ANSISTR:
660 			isapnp_parse_name(dev->name, sizeof(dev->name), &size);
661 			break;
662 		case _LTAG_UNICODESTR:
663 			/* silently ignore */
664 			/* who use unicode for hardware identification? */
665 			break;
666 		case _LTAG_VENDOR:
667 			break;
668 		case _LTAG_MEM32RANGE:
669 			if (size != 17)
670 				goto __skip;
671 			isapnp_parse_mem32_resource(dev, option_flags, size);
672 			size = 0;
673 			break;
674 		case _LTAG_FIXEDMEM32RANGE:
675 			if (size != 9)
676 				goto __skip;
677 			isapnp_parse_fixed_mem32_resource(dev, option_flags,
678 							  size);
679 			size = 0;
680 			break;
681 		case _STAG_END:
682 			if (size > 0)
683 				isapnp_skip_bytes(size);
684 			return 1;
685 		default:
686 			dev_err(&dev->dev, "unknown tag %#x (card %i), "
687 				"ignored\n", type, card->number);
688 		}
689 __skip:
690 		if (size > 0)
691 			isapnp_skip_bytes(size);
692 	}
693 	return 0;
694 }
695 
696 /*
697  *  Parse resource map for ISA PnP card.
698  */
699 static void __init isapnp_parse_resource_map(struct pnp_card *card)
700 {
701 	unsigned char type, tmp[17];
702 	unsigned short size;
703 
704 	while (1) {
705 		if (isapnp_read_tag(&type, &size) < 0)
706 			return;
707 		switch (type) {
708 		case _STAG_PNPVERNO:
709 			if (size != 2)
710 				goto __skip;
711 			isapnp_peek(tmp, 2);
712 			card->pnpver = tmp[0];
713 			card->productver = tmp[1];
714 			size = 0;
715 			break;
716 		case _STAG_LOGDEVID:
717 			if (size >= 5 && size <= 6) {
718 				if (isapnp_create_device(card, size) == 1)
719 					return;
720 				size = 0;
721 			}
722 			break;
723 		case _STAG_VENDOR:
724 			break;
725 		case _LTAG_ANSISTR:
726 			isapnp_parse_name(card->name, sizeof(card->name),
727 					  &size);
728 			break;
729 		case _LTAG_UNICODESTR:
730 			/* silently ignore */
731 			/* who use unicode for hardware identification? */
732 			break;
733 		case _LTAG_VENDOR:
734 			break;
735 		case _STAG_END:
736 			if (size > 0)
737 				isapnp_skip_bytes(size);
738 			return;
739 		default:
740 			dev_err(&card->dev, "unknown tag %#x, ignored\n",
741 			       type);
742 		}
743 __skip:
744 		if (size > 0)
745 			isapnp_skip_bytes(size);
746 	}
747 }
748 
749 /*
750  *  Compute ISA PnP checksum for first eight bytes.
751  */
752 static unsigned char __init isapnp_checksum(unsigned char *data)
753 {
754 	int i, j;
755 	unsigned char checksum = 0x6a, bit, b;
756 
757 	for (i = 0; i < 8; i++) {
758 		b = data[i];
759 		for (j = 0; j < 8; j++) {
760 			bit = 0;
761 			if (b & (1 << j))
762 				bit = 1;
763 			checksum =
764 			    ((((checksum ^ (checksum >> 1)) & 0x01) ^ bit) << 7)
765 			    | (checksum >> 1);
766 		}
767 	}
768 	return checksum;
769 }
770 
771 /*
772  *  Build device list for all present ISA PnP devices.
773  */
774 static int __init isapnp_build_device_list(void)
775 {
776 	int csn;
777 	unsigned char header[9], checksum;
778 	struct pnp_card *card;
779 	u32 eisa_id;
780 	char id[8];
781 
782 	isapnp_wait();
783 	isapnp_key();
784 	for (csn = 1; csn <= isapnp_csn_count; csn++) {
785 		isapnp_wake(csn);
786 		isapnp_peek(header, 9);
787 		checksum = isapnp_checksum(header);
788 		eisa_id = header[0] | header[1] << 8 |
789 			  header[2] << 16 | header[3] << 24;
790 		pnp_eisa_id_to_string(eisa_id, id);
791 		card = pnp_alloc_card(&isapnp_protocol, csn, id);
792 		if (!card)
793 			continue;
794 
795 		INIT_LIST_HEAD(&card->devices);
796 		card->serial =
797 		    (header[7] << 24) | (header[6] << 16) | (header[5] << 8) |
798 		    header[4];
799 		isapnp_checksum_value = 0x00;
800 		isapnp_parse_resource_map(card);
801 		if (isapnp_checksum_value != 0x00)
802 			dev_err(&card->dev, "invalid checksum %#x\n",
803 				isapnp_checksum_value);
804 		card->checksum = isapnp_checksum_value;
805 
806 		pnp_add_card(card);
807 	}
808 	isapnp_wait();
809 	return 0;
810 }
811 
812 /*
813  *  Basic configuration routines.
814  */
815 
816 int isapnp_present(void)
817 {
818 	struct pnp_card *card;
819 
820 	pnp_for_each_card(card) {
821 		if (card->protocol == &isapnp_protocol)
822 			return 1;
823 	}
824 	return 0;
825 }
826 
827 int isapnp_cfg_begin(int csn, int logdev)
828 {
829 	if (csn < 1 || csn > isapnp_csn_count || logdev > 10)
830 		return -EINVAL;
831 	mutex_lock(&isapnp_cfg_mutex);
832 	isapnp_wait();
833 	isapnp_key();
834 	isapnp_wake(csn);
835 #if 0
836 	/* to avoid malfunction when the isapnptools package is used */
837 	/* we must set RDP to our value again */
838 	/* it is possible to set RDP only in the isolation phase */
839 	/*   Jens Thoms Toerring <Jens.Toerring@physik.fu-berlin.de> */
840 	isapnp_write_byte(0x02, 0x04);	/* clear CSN of card */
841 	mdelay(2);		/* is this necessary? */
842 	isapnp_wake(csn);	/* bring card into sleep state */
843 	isapnp_wake(0);		/* bring card into isolation state */
844 	isapnp_set_rdp();	/* reset the RDP port */
845 	udelay(1000);		/* delay 1000us */
846 	isapnp_write_byte(0x06, csn);	/* reset CSN to previous value */
847 	udelay(250);		/* is this necessary? */
848 #endif
849 	if (logdev >= 0)
850 		isapnp_device(logdev);
851 	return 0;
852 }
853 
854 int isapnp_cfg_end(void)
855 {
856 	isapnp_wait();
857 	mutex_unlock(&isapnp_cfg_mutex);
858 	return 0;
859 }
860 
861 /*
862  *  Initialization.
863  */
864 
865 EXPORT_SYMBOL(isapnp_protocol);
866 EXPORT_SYMBOL(isapnp_present);
867 EXPORT_SYMBOL(isapnp_cfg_begin);
868 EXPORT_SYMBOL(isapnp_cfg_end);
869 EXPORT_SYMBOL(isapnp_write_byte);
870 
871 static int isapnp_get_resources(struct pnp_dev *dev)
872 {
873 	int i, ret;
874 
875 	pnp_dbg(&dev->dev, "get resources\n");
876 	pnp_init_resources(dev);
877 	isapnp_cfg_begin(dev->card->number, dev->number);
878 	dev->active = isapnp_read_byte(ISAPNP_CFG_ACTIVATE);
879 	if (!dev->active)
880 		goto __end;
881 
882 	for (i = 0; i < ISAPNP_MAX_PORT; i++) {
883 		ret = isapnp_read_word(ISAPNP_CFG_PORT + (i << 1));
884 		pnp_add_io_resource(dev, ret, ret,
885 				    ret == 0 ? IORESOURCE_DISABLED : 0);
886 	}
887 	for (i = 0; i < ISAPNP_MAX_MEM; i++) {
888 		ret = isapnp_read_word(ISAPNP_CFG_MEM + (i << 3)) << 8;
889 		pnp_add_mem_resource(dev, ret, ret,
890 				     ret == 0 ? IORESOURCE_DISABLED : 0);
891 	}
892 	for (i = 0; i < ISAPNP_MAX_IRQ; i++) {
893 		ret = isapnp_read_word(ISAPNP_CFG_IRQ + (i << 1)) >> 8;
894 		pnp_add_irq_resource(dev, ret,
895 				     ret == 0 ? IORESOURCE_DISABLED : 0);
896 	}
897 	for (i = 0; i < ISAPNP_MAX_DMA; i++) {
898 		ret = isapnp_read_byte(ISAPNP_CFG_DMA + i);
899 		pnp_add_dma_resource(dev, ret,
900 				     ret == 4 ? IORESOURCE_DISABLED : 0);
901 	}
902 
903 __end:
904 	isapnp_cfg_end();
905 	return 0;
906 }
907 
908 static int isapnp_set_resources(struct pnp_dev *dev)
909 {
910 	struct resource *res;
911 	int tmp;
912 
913 	pnp_dbg(&dev->dev, "set resources\n");
914 	isapnp_cfg_begin(dev->card->number, dev->number);
915 	dev->active = 1;
916 	for (tmp = 0; tmp < ISAPNP_MAX_PORT; tmp++) {
917 		res = pnp_get_resource(dev, IORESOURCE_IO, tmp);
918 		if (pnp_resource_enabled(res)) {
919 			pnp_dbg(&dev->dev, "  set io  %d to %#llx\n",
920 				tmp, (unsigned long long) res->start);
921 			isapnp_write_word(ISAPNP_CFG_PORT + (tmp << 1),
922 					  res->start);
923 		}
924 	}
925 	for (tmp = 0; tmp < ISAPNP_MAX_IRQ; tmp++) {
926 		res = pnp_get_resource(dev, IORESOURCE_IRQ, tmp);
927 		if (pnp_resource_enabled(res)) {
928 			int irq = res->start;
929 			if (irq == 2)
930 				irq = 9;
931 			pnp_dbg(&dev->dev, "  set irq %d to %d\n", tmp, irq);
932 			isapnp_write_byte(ISAPNP_CFG_IRQ + (tmp << 1), irq);
933 		}
934 	}
935 	for (tmp = 0; tmp < ISAPNP_MAX_DMA; tmp++) {
936 		res = pnp_get_resource(dev, IORESOURCE_DMA, tmp);
937 		if (pnp_resource_enabled(res)) {
938 			pnp_dbg(&dev->dev, "  set dma %d to %lld\n",
939 				tmp, (unsigned long long) res->start);
940 			isapnp_write_byte(ISAPNP_CFG_DMA + tmp, res->start);
941 		}
942 	}
943 	for (tmp = 0; tmp < ISAPNP_MAX_MEM; tmp++) {
944 		res = pnp_get_resource(dev, IORESOURCE_MEM, tmp);
945 		if (pnp_resource_enabled(res)) {
946 			pnp_dbg(&dev->dev, "  set mem %d to %#llx\n",
947 				tmp, (unsigned long long) res->start);
948 			isapnp_write_word(ISAPNP_CFG_MEM + (tmp << 3),
949 					  (res->start >> 8) & 0xffff);
950 		}
951 	}
952 	/* FIXME: We aren't handling 32bit mems properly here */
953 	isapnp_activate(dev->number);
954 	isapnp_cfg_end();
955 	return 0;
956 }
957 
958 static int isapnp_disable_resources(struct pnp_dev *dev)
959 {
960 	if (!dev->active)
961 		return -EINVAL;
962 	isapnp_cfg_begin(dev->card->number, dev->number);
963 	isapnp_deactivate(dev->number);
964 	dev->active = 0;
965 	isapnp_cfg_end();
966 	return 0;
967 }
968 
969 struct pnp_protocol isapnp_protocol = {
970 	.name = "ISA Plug and Play",
971 	.get = isapnp_get_resources,
972 	.set = isapnp_set_resources,
973 	.disable = isapnp_disable_resources,
974 };
975 
976 static int __init isapnp_init(void)
977 {
978 	int cards;
979 	struct pnp_card *card;
980 	struct pnp_dev *dev;
981 
982 	if (isapnp_disable) {
983 		printk(KERN_INFO "isapnp: ISA Plug & Play support disabled\n");
984 		return 0;
985 	}
986 #ifdef CONFIG_PPC
987 	if (check_legacy_ioport(_PIDXR) || check_legacy_ioport(_PNPWRP))
988 		return -EINVAL;
989 #endif
990 #ifdef ISAPNP_REGION_OK
991 	if (!request_region(_PIDXR, 1, "isapnp index")) {
992 		printk(KERN_ERR "isapnp: Index Register 0x%x already used\n",
993 		       _PIDXR);
994 		return -EBUSY;
995 	}
996 #endif
997 	if (!request_region(_PNPWRP, 1, "isapnp write")) {
998 		printk(KERN_ERR
999 		       "isapnp: Write Data Register 0x%x already used\n",
1000 		       _PNPWRP);
1001 #ifdef ISAPNP_REGION_OK
1002 		release_region(_PIDXR, 1);
1003 #endif
1004 		return -EBUSY;
1005 	}
1006 
1007 	if (pnp_register_protocol(&isapnp_protocol) < 0)
1008 		return -EBUSY;
1009 
1010 	/*
1011 	 *      Print a message. The existing ISAPnP code is hanging machines
1012 	 *      so let the user know where.
1013 	 */
1014 
1015 	printk(KERN_INFO "isapnp: Scanning for PnP cards...\n");
1016 	if (isapnp_rdp >= 0x203 && isapnp_rdp <= 0x3ff) {
1017 		isapnp_rdp |= 3;
1018 		if (!request_region(isapnp_rdp, 1, "isapnp read")) {
1019 			printk(KERN_ERR
1020 			       "isapnp: Read Data Register 0x%x already used\n",
1021 			       isapnp_rdp);
1022 #ifdef ISAPNP_REGION_OK
1023 			release_region(_PIDXR, 1);
1024 #endif
1025 			release_region(_PNPWRP, 1);
1026 			return -EBUSY;
1027 		}
1028 		isapnp_set_rdp();
1029 	}
1030 	if (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff) {
1031 		cards = isapnp_isolate();
1032 		if (cards < 0 || (isapnp_rdp < 0x203 || isapnp_rdp > 0x3ff)) {
1033 #ifdef ISAPNP_REGION_OK
1034 			release_region(_PIDXR, 1);
1035 #endif
1036 			release_region(_PNPWRP, 1);
1037 			printk(KERN_INFO
1038 			       "isapnp: No Plug & Play device found\n");
1039 			return 0;
1040 		}
1041 		request_region(isapnp_rdp, 1, "isapnp read");
1042 	}
1043 	isapnp_build_device_list();
1044 	cards = 0;
1045 
1046 	protocol_for_each_card(&isapnp_protocol, card) {
1047 		cards++;
1048 		if (isapnp_verbose) {
1049 			dev_info(&card->dev, "card '%s'\n",
1050 			       card->name[0] ? card->name : "unknown");
1051 			if (isapnp_verbose < 2)
1052 				continue;
1053 			card_for_each_dev(card, dev) {
1054 				dev_info(&card->dev, "device '%s'\n",
1055 				       dev->name[0] ? dev->name : "unknown");
1056 			}
1057 		}
1058 	}
1059 	if (cards)
1060 		printk(KERN_INFO
1061 		       "isapnp: %i Plug & Play card%s detected total\n", cards,
1062 		       cards > 1 ? "s" : "");
1063 	else
1064 		printk(KERN_INFO "isapnp: No Plug & Play card found\n");
1065 
1066 	isapnp_proc_init();
1067 	return 0;
1068 }
1069 
1070 device_initcall(isapnp_init);
1071 
1072 /* format is: noisapnp */
1073 
1074 static int __init isapnp_setup_disable(char *str)
1075 {
1076 	isapnp_disable = 1;
1077 	return 1;
1078 }
1079 
1080 __setup("noisapnp", isapnp_setup_disable);
1081 
1082 /* format is: isapnp=rdp,reset,skip_pci_scan,verbose */
1083 
1084 static int __init isapnp_setup_isapnp(char *str)
1085 {
1086 	(void)((get_option(&str, &isapnp_rdp) == 2) &&
1087 	       (get_option(&str, &isapnp_reset) == 2) &&
1088 	       (get_option(&str, &isapnp_verbose) == 2));
1089 	return 1;
1090 }
1091 
1092 __setup("isapnp=", isapnp_setup_isapnp);
1093