xref: /openbmc/linux/drivers/scsi/sym53c8xx_2/sym_nvram.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family
3  * of PCI-SCSI IO processors.
4  *
5  * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
6  *
7  * This driver is derived from the Linux sym53c8xx driver.
8  * Copyright (C) 1998-2000  Gerard Roudier
9  *
10  * The sym53c8xx driver is derived from the ncr53c8xx driver that had been
11  * a port of the FreeBSD ncr driver to Linux-1.2.13.
12  *
13  * The original ncr driver has been written for 386bsd and FreeBSD by
14  *         Wolfgang Stanglmeier        <wolf@cologne.de>
15  *         Stefan Esser                <se@mi.Uni-Koeln.de>
16  * Copyright (C) 1994  Wolfgang Stanglmeier
17  *
18  * Other major contributions:
19  *
20  * NVRAM detection and reading.
21  * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
22  *
23  *-----------------------------------------------------------------------------
24  *
25  * This program is free software; you can redistribute it and/or modify
26  * it under the terms of the GNU General Public License as published by
27  * the Free Software Foundation; either version 2 of the License, or
28  * (at your option) any later version.
29  *
30  * This program is distributed in the hope that it will be useful,
31  * but WITHOUT ANY WARRANTY; without even the implied warranty of
32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
33  * GNU General Public License for more details.
34  *
35  * You should have received a copy of the GNU General Public License
36  * along with this program; if not, write to the Free Software
37  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
38  */
39 
40 #include "sym_glue.h"
41 #include "sym_nvram.h"
42 
43 #ifdef	SYM_CONF_DEBUG_NVRAM
44 static u_char Tekram_boot_delay[7] = {3, 5, 10, 20, 30, 60, 120};
45 #endif
46 
47 /*
48  *  Get host setup from NVRAM.
49  */
50 void sym_nvram_setup_host(struct Scsi_Host *shost, struct sym_hcb *np, struct sym_nvram *nvram)
51 {
52 	/*
53 	 *  Get parity checking, host ID, verbose mode
54 	 *  and miscellaneous host flags from NVRAM.
55 	 */
56 	switch (nvram->type) {
57 	case SYM_SYMBIOS_NVRAM:
58 		if (!(nvram->data.Symbios.flags & SYMBIOS_PARITY_ENABLE))
59 			np->rv_scntl0  &= ~0x0a;
60 		np->myaddr = nvram->data.Symbios.host_id & 0x0f;
61 		if (nvram->data.Symbios.flags & SYMBIOS_VERBOSE_MSGS)
62 			np->verbose += 1;
63 		if (nvram->data.Symbios.flags1 & SYMBIOS_SCAN_HI_LO)
64 			shost->reverse_ordering = 1;
65 		if (nvram->data.Symbios.flags2 & SYMBIOS_AVOID_BUS_RESET)
66 			np->usrflags |= SYM_AVOID_BUS_RESET;
67 		break;
68 	case SYM_TEKRAM_NVRAM:
69 		np->myaddr = nvram->data.Tekram.host_id & 0x0f;
70 		break;
71 #ifdef CONFIG_PARISC
72 	case SYM_PARISC_PDC:
73 		if (nvram->data.parisc.host_id != -1)
74 			np->myaddr = nvram->data.parisc.host_id;
75 		if (nvram->data.parisc.factor != -1)
76 			np->minsync = nvram->data.parisc.factor;
77 		if (nvram->data.parisc.width != -1)
78 			np->maxwide = nvram->data.parisc.width;
79 		switch (nvram->data.parisc.mode) {
80 			case 0: np->scsi_mode = SMODE_SE; break;
81 			case 1: np->scsi_mode = SMODE_HVD; break;
82 			case 2: np->scsi_mode = SMODE_LVD; break;
83 			default: break;
84 		}
85 #endif
86 	default:
87 		break;
88 	}
89 }
90 
91 /*
92  *  Get target set-up from Symbios format NVRAM.
93  */
94 static void
95 sym_Symbios_setup_target(struct sym_hcb *np, int target, Symbios_nvram *nvram)
96 {
97 	struct sym_tcb *tp = &np->target[target];
98 	Symbios_target *tn = &nvram->target[target];
99 
100 	tp->usrtags =
101 		(tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? SYM_SETUP_MAX_TAG : 0;
102 
103 	if (!(tn->flags & SYMBIOS_DISCONNECT_ENABLE))
104 		tp->usrflags &= ~SYM_DISC_ENABLED;
105 	if (!(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME))
106 		tp->usrflags |= SYM_SCAN_BOOT_DISABLED;
107 	if (!(tn->flags & SYMBIOS_SCAN_LUNS))
108 		tp->usrflags |= SYM_SCAN_LUNS_DISABLED;
109 }
110 
111 /*
112  *  Get target set-up from Tekram format NVRAM.
113  */
114 static void
115 sym_Tekram_setup_target(struct sym_hcb *np, int target, Tekram_nvram *nvram)
116 {
117 	struct sym_tcb *tp = &np->target[target];
118 	struct Tekram_target *tn = &nvram->target[target];
119 
120 	if (tn->flags & TEKRAM_TAGGED_COMMANDS) {
121 		tp->usrtags = 2 << nvram->max_tags_index;
122 	}
123 
124 	if (tn->flags & TEKRAM_DISCONNECT_ENABLE)
125 		tp->usrflags |= SYM_DISC_ENABLED;
126 
127 	/* If any device does not support parity, we will not use this option */
128 	if (!(tn->flags & TEKRAM_PARITY_CHECK))
129 		np->rv_scntl0  &= ~0x0a; /* SCSI parity checking disabled */
130 }
131 
132 /*
133  *  Get target setup from NVRAM.
134  */
135 void sym_nvram_setup_target(struct sym_hcb *np, int target, struct sym_nvram *nvp)
136 {
137 	switch (nvp->type) {
138 	case SYM_SYMBIOS_NVRAM:
139 		sym_Symbios_setup_target(np, target, &nvp->data.Symbios);
140 		break;
141 	case SYM_TEKRAM_NVRAM:
142 		sym_Tekram_setup_target(np, target, &nvp->data.Tekram);
143 		break;
144 	default:
145 		break;
146 	}
147 }
148 
149 #ifdef	SYM_CONF_DEBUG_NVRAM
150 /*
151  *  Dump Symbios format NVRAM for debugging purpose.
152  */
153 static void sym_display_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram)
154 {
155 	int i;
156 
157 	/* display Symbios nvram host data */
158 	printf("%s: HOST ID=%d%s%s%s%s%s%s\n",
159 		sym_name(np), nvram->host_id & 0x0f,
160 		(nvram->flags  & SYMBIOS_SCAM_ENABLE)	? " SCAM"	:"",
161 		(nvram->flags  & SYMBIOS_PARITY_ENABLE)	? " PARITY"	:"",
162 		(nvram->flags  & SYMBIOS_VERBOSE_MSGS)	? " VERBOSE"	:"",
163 		(nvram->flags  & SYMBIOS_CHS_MAPPING)	? " CHS_ALT"	:"",
164 		(nvram->flags2 & SYMBIOS_AVOID_BUS_RESET)?" NO_RESET"	:"",
165 		(nvram->flags1 & SYMBIOS_SCAN_HI_LO)	? " HI_LO"	:"");
166 
167 	/* display Symbios nvram drive data */
168 	for (i = 0 ; i < 15 ; i++) {
169 		struct Symbios_target *tn = &nvram->target[i];
170 		printf("%s-%d:%s%s%s%s WIDTH=%d SYNC=%d TMO=%d\n",
171 		sym_name(np), i,
172 		(tn->flags & SYMBIOS_DISCONNECT_ENABLE)	? " DISC"	: "",
173 		(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME)	? " SCAN_BOOT"	: "",
174 		(tn->flags & SYMBIOS_SCAN_LUNS)		? " SCAN_LUNS"	: "",
175 		(tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? " TCQ"	: "",
176 		tn->bus_width,
177 		tn->sync_period / 4,
178 		tn->timeout);
179 	}
180 }
181 
182 /*
183  *  Dump TEKRAM format NVRAM for debugging purpose.
184  */
185 static void sym_display_Tekram_nvram(struct sym_device *np, Tekram_nvram *nvram)
186 {
187 	int i, tags, boot_delay;
188 	char *rem;
189 
190 	/* display Tekram nvram host data */
191 	tags = 2 << nvram->max_tags_index;
192 	boot_delay = 0;
193 	if (nvram->boot_delay_index < 6)
194 		boot_delay = Tekram_boot_delay[nvram->boot_delay_index];
195 	switch ((nvram->flags & TEKRAM_REMOVABLE_FLAGS) >> 6) {
196 	default:
197 	case 0:	rem = "";			break;
198 	case 1: rem = " REMOVABLE=boot device";	break;
199 	case 2: rem = " REMOVABLE=all";		break;
200 	}
201 
202 	printf("%s: HOST ID=%d%s%s%s%s%s%s%s%s%s BOOT DELAY=%d tags=%d\n",
203 		sym_name(np), nvram->host_id & 0x0f,
204 		(nvram->flags1 & SYMBIOS_SCAM_ENABLE)	? " SCAM"	:"",
205 		(nvram->flags & TEKRAM_MORE_THAN_2_DRIVES) ? " >2DRIVES":"",
206 		(nvram->flags & TEKRAM_DRIVES_SUP_1GB)	? " >1GB"	:"",
207 		(nvram->flags & TEKRAM_RESET_ON_POWER_ON) ? " RESET"	:"",
208 		(nvram->flags & TEKRAM_ACTIVE_NEGATION)	? " ACT_NEG"	:"",
209 		(nvram->flags & TEKRAM_IMMEDIATE_SEEK)	? " IMM_SEEK"	:"",
210 		(nvram->flags & TEKRAM_SCAN_LUNS)	? " SCAN_LUNS"	:"",
211 		(nvram->flags1 & TEKRAM_F2_F6_ENABLED)	? " F2_F6"	:"",
212 		rem, boot_delay, tags);
213 
214 	/* display Tekram nvram drive data */
215 	for (i = 0; i <= 15; i++) {
216 		int sync, j;
217 		struct Tekram_target *tn = &nvram->target[i];
218 		j = tn->sync_index & 0xf;
219 		sync = Tekram_sync[j];
220 		printf("%s-%d:%s%s%s%s%s%s PERIOD=%d\n",
221 		sym_name(np), i,
222 		(tn->flags & TEKRAM_PARITY_CHECK)	? " PARITY"	: "",
223 		(tn->flags & TEKRAM_SYNC_NEGO)		? " SYNC"	: "",
224 		(tn->flags & TEKRAM_DISCONNECT_ENABLE)	? " DISC"	: "",
225 		(tn->flags & TEKRAM_START_CMD)		? " START"	: "",
226 		(tn->flags & TEKRAM_TAGGED_COMMANDS)	? " TCQ"	: "",
227 		(tn->flags & TEKRAM_WIDE_NEGO)		? " WIDE"	: "",
228 		sync);
229 	}
230 }
231 #else
232 static void sym_display_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram) { (void)np; (void)nvram; }
233 static void sym_display_Tekram_nvram(struct sym_device *np, Tekram_nvram *nvram) { (void)np; (void)nvram; }
234 #endif	/* SYM_CONF_DEBUG_NVRAM */
235 
236 
237 /*
238  *  24C16 EEPROM reading.
239  *
240  *  GPOI0 - data in/data out
241  *  GPIO1 - clock
242  *  Symbios NVRAM wiring now also used by Tekram.
243  */
244 
245 #define SET_BIT 0
246 #define CLR_BIT 1
247 #define SET_CLK 2
248 #define CLR_CLK 3
249 
250 /*
251  *  Set/clear data/clock bit in GPIO0
252  */
253 static void S24C16_set_bit(struct sym_device *np, u_char write_bit, u_char *gpreg,
254 			  int bit_mode)
255 {
256 	udelay(5);
257 	switch (bit_mode) {
258 	case SET_BIT:
259 		*gpreg |= write_bit;
260 		break;
261 	case CLR_BIT:
262 		*gpreg &= 0xfe;
263 		break;
264 	case SET_CLK:
265 		*gpreg |= 0x02;
266 		break;
267 	case CLR_CLK:
268 		*gpreg &= 0xfd;
269 		break;
270 
271 	}
272 	OUTB(np, nc_gpreg, *gpreg);
273 	udelay(5);
274 }
275 
276 /*
277  *  Send START condition to NVRAM to wake it up.
278  */
279 static void S24C16_start(struct sym_device *np, u_char *gpreg)
280 {
281 	S24C16_set_bit(np, 1, gpreg, SET_BIT);
282 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
283 	S24C16_set_bit(np, 0, gpreg, CLR_BIT);
284 	S24C16_set_bit(np, 0, gpreg, CLR_CLK);
285 }
286 
287 /*
288  *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZzzzz!!
289  */
290 static void S24C16_stop(struct sym_device *np, u_char *gpreg)
291 {
292 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
293 	S24C16_set_bit(np, 1, gpreg, SET_BIT);
294 }
295 
296 /*
297  *  Read or write a bit to the NVRAM,
298  *  read if GPIO0 input else write if GPIO0 output
299  */
300 static void S24C16_do_bit(struct sym_device *np, u_char *read_bit, u_char write_bit,
301 			 u_char *gpreg)
302 {
303 	S24C16_set_bit(np, write_bit, gpreg, SET_BIT);
304 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
305 	if (read_bit)
306 		*read_bit = INB(np, nc_gpreg);
307 	S24C16_set_bit(np, 0, gpreg, CLR_CLK);
308 	S24C16_set_bit(np, 0, gpreg, CLR_BIT);
309 }
310 
311 /*
312  *  Output an ACK to the NVRAM after reading,
313  *  change GPIO0 to output and when done back to an input
314  */
315 static void S24C16_write_ack(struct sym_device *np, u_char write_bit, u_char *gpreg,
316 			    u_char *gpcntl)
317 {
318 	OUTB(np, nc_gpcntl, *gpcntl & 0xfe);
319 	S24C16_do_bit(np, NULL, write_bit, gpreg);
320 	OUTB(np, nc_gpcntl, *gpcntl);
321 }
322 
323 /*
324  *  Input an ACK from NVRAM after writing,
325  *  change GPIO0 to input and when done back to an output
326  */
327 static void S24C16_read_ack(struct sym_device *np, u_char *read_bit, u_char *gpreg,
328 			   u_char *gpcntl)
329 {
330 	OUTB(np, nc_gpcntl, *gpcntl | 0x01);
331 	S24C16_do_bit(np, read_bit, 1, gpreg);
332 	OUTB(np, nc_gpcntl, *gpcntl);
333 }
334 
335 /*
336  *  WRITE a byte to the NVRAM and then get an ACK to see it was accepted OK,
337  *  GPIO0 must already be set as an output
338  */
339 static void S24C16_write_byte(struct sym_device *np, u_char *ack_data, u_char write_data,
340 			     u_char *gpreg, u_char *gpcntl)
341 {
342 	int x;
343 
344 	for (x = 0; x < 8; x++)
345 		S24C16_do_bit(np, NULL, (write_data >> (7 - x)) & 0x01, gpreg);
346 
347 	S24C16_read_ack(np, ack_data, gpreg, gpcntl);
348 }
349 
350 /*
351  *  READ a byte from the NVRAM and then send an ACK to say we have got it,
352  *  GPIO0 must already be set as an input
353  */
354 static void S24C16_read_byte(struct sym_device *np, u_char *read_data, u_char ack_data,
355 			    u_char *gpreg, u_char *gpcntl)
356 {
357 	int x;
358 	u_char read_bit;
359 
360 	*read_data = 0;
361 	for (x = 0; x < 8; x++) {
362 		S24C16_do_bit(np, &read_bit, 1, gpreg);
363 		*read_data |= ((read_bit & 0x01) << (7 - x));
364 	}
365 
366 	S24C16_write_ack(np, ack_data, gpreg, gpcntl);
367 }
368 
369 #if SYM_CONF_NVRAM_WRITE_SUPPORT
370 /*
371  *  Write 'len' bytes starting at 'offset'.
372  */
373 static int sym_write_S24C16_nvram(struct sym_device *np, int offset,
374 		u_char *data, int len)
375 {
376 	u_char	gpcntl, gpreg;
377 	u_char	old_gpcntl, old_gpreg;
378 	u_char	ack_data;
379 	int	x;
380 
381 	/* save current state of GPCNTL and GPREG */
382 	old_gpreg	= INB(np, nc_gpreg);
383 	old_gpcntl	= INB(np, nc_gpcntl);
384 	gpcntl		= old_gpcntl & 0x1c;
385 
386 	/* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
387 	OUTB(np, nc_gpreg,  old_gpreg);
388 	OUTB(np, nc_gpcntl, gpcntl);
389 
390 	/* this is to set NVRAM into a known state with GPIO0/1 both low */
391 	gpreg = old_gpreg;
392 	S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
393 	S24C16_set_bit(np, 0, &gpreg, CLR_BIT);
394 
395 	/* now set NVRAM inactive with GPIO0/1 both high */
396 	S24C16_stop(np, &gpreg);
397 
398 	/* NVRAM has to be written in segments of 16 bytes */
399 	for (x = 0; x < len ; x += 16) {
400 		do {
401 			S24C16_start(np, &gpreg);
402 			S24C16_write_byte(np, &ack_data,
403 					  0xa0 | (((offset+x) >> 7) & 0x0e),
404 					  &gpreg, &gpcntl);
405 		} while (ack_data & 0x01);
406 
407 		S24C16_write_byte(np, &ack_data, (offset+x) & 0xff,
408 				  &gpreg, &gpcntl);
409 
410 		for (y = 0; y < 16; y++)
411 			S24C16_write_byte(np, &ack_data, data[x+y],
412 					  &gpreg, &gpcntl);
413 		S24C16_stop(np, &gpreg);
414 	}
415 
416 	/* return GPIO0/1 to original states after having accessed NVRAM */
417 	OUTB(np, nc_gpcntl, old_gpcntl);
418 	OUTB(np, nc_gpreg,  old_gpreg);
419 
420 	return 0;
421 }
422 #endif /* SYM_CONF_NVRAM_WRITE_SUPPORT */
423 
424 /*
425  *  Read 'len' bytes starting at 'offset'.
426  */
427 static int sym_read_S24C16_nvram(struct sym_device *np, int offset, u_char *data, int len)
428 {
429 	u_char	gpcntl, gpreg;
430 	u_char	old_gpcntl, old_gpreg;
431 	u_char	ack_data;
432 	int	retv = 1;
433 	int	x;
434 
435 	/* save current state of GPCNTL and GPREG */
436 	old_gpreg	= INB(np, nc_gpreg);
437 	old_gpcntl	= INB(np, nc_gpcntl);
438 	gpcntl		= old_gpcntl & 0x1c;
439 
440 	/* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
441 	OUTB(np, nc_gpreg,  old_gpreg);
442 	OUTB(np, nc_gpcntl, gpcntl);
443 
444 	/* this is to set NVRAM into a known state with GPIO0/1 both low */
445 	gpreg = old_gpreg;
446 	S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
447 	S24C16_set_bit(np, 0, &gpreg, CLR_BIT);
448 
449 	/* now set NVRAM inactive with GPIO0/1 both high */
450 	S24C16_stop(np, &gpreg);
451 
452 	/* activate NVRAM */
453 	S24C16_start(np, &gpreg);
454 
455 	/* write device code and random address MSB */
456 	S24C16_write_byte(np, &ack_data,
457 		0xa0 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
458 	if (ack_data & 0x01)
459 		goto out;
460 
461 	/* write random address LSB */
462 	S24C16_write_byte(np, &ack_data,
463 		offset & 0xff, &gpreg, &gpcntl);
464 	if (ack_data & 0x01)
465 		goto out;
466 
467 	/* regenerate START state to set up for reading */
468 	S24C16_start(np, &gpreg);
469 
470 	/* rewrite device code and address MSB with read bit set (lsb = 0x01) */
471 	S24C16_write_byte(np, &ack_data,
472 		0xa1 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
473 	if (ack_data & 0x01)
474 		goto out;
475 
476 	/* now set up GPIO0 for inputting data */
477 	gpcntl |= 0x01;
478 	OUTB(np, nc_gpcntl, gpcntl);
479 
480 	/* input all requested data - only part of total NVRAM */
481 	for (x = 0; x < len; x++)
482 		S24C16_read_byte(np, &data[x], (x == (len-1)), &gpreg, &gpcntl);
483 
484 	/* finally put NVRAM back in inactive mode */
485 	gpcntl &= 0xfe;
486 	OUTB(np, nc_gpcntl, gpcntl);
487 	S24C16_stop(np, &gpreg);
488 	retv = 0;
489 out:
490 	/* return GPIO0/1 to original states after having accessed NVRAM */
491 	OUTB(np, nc_gpcntl, old_gpcntl);
492 	OUTB(np, nc_gpreg,  old_gpreg);
493 
494 	return retv;
495 }
496 
497 #undef SET_BIT
498 #undef CLR_BIT
499 #undef SET_CLK
500 #undef CLR_CLK
501 
502 /*
503  *  Try reading Symbios NVRAM.
504  *  Return 0 if OK.
505  */
506 static int sym_read_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram)
507 {
508 	static u_char Symbios_trailer[6] = {0xfe, 0xfe, 0, 0, 0, 0};
509 	u_char *data = (u_char *) nvram;
510 	int len  = sizeof(*nvram);
511 	u_short	csum;
512 	int x;
513 
514 	/* probe the 24c16 and read the SYMBIOS 24c16 area */
515 	if (sym_read_S24C16_nvram (np, SYMBIOS_NVRAM_ADDRESS, data, len))
516 		return 1;
517 
518 	/* check valid NVRAM signature, verify byte count and checksum */
519 	if (nvram->type != 0 ||
520 	    memcmp(nvram->trailer, Symbios_trailer, 6) ||
521 	    nvram->byte_count != len - 12)
522 		return 1;
523 
524 	/* verify checksum */
525 	for (x = 6, csum = 0; x < len - 6; x++)
526 		csum += data[x];
527 	if (csum != nvram->checksum)
528 		return 1;
529 
530 	return 0;
531 }
532 
533 /*
534  *  93C46 EEPROM reading.
535  *
536  *  GPOI0 - data in
537  *  GPIO1 - data out
538  *  GPIO2 - clock
539  *  GPIO4 - chip select
540  *
541  *  Used by Tekram.
542  */
543 
544 /*
545  *  Pulse clock bit in GPIO0
546  */
547 static void T93C46_Clk(struct sym_device *np, u_char *gpreg)
548 {
549 	OUTB(np, nc_gpreg, *gpreg | 0x04);
550 	udelay(2);
551 	OUTB(np, nc_gpreg, *gpreg);
552 }
553 
554 /*
555  *  Read bit from NVRAM
556  */
557 static void T93C46_Read_Bit(struct sym_device *np, u_char *read_bit, u_char *gpreg)
558 {
559 	udelay(2);
560 	T93C46_Clk(np, gpreg);
561 	*read_bit = INB(np, nc_gpreg);
562 }
563 
564 /*
565  *  Write bit to GPIO0
566  */
567 static void T93C46_Write_Bit(struct sym_device *np, u_char write_bit, u_char *gpreg)
568 {
569 	if (write_bit & 0x01)
570 		*gpreg |= 0x02;
571 	else
572 		*gpreg &= 0xfd;
573 
574 	*gpreg |= 0x10;
575 
576 	OUTB(np, nc_gpreg, *gpreg);
577 	udelay(2);
578 
579 	T93C46_Clk(np, gpreg);
580 }
581 
582 /*
583  *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZZzzz!!
584  */
585 static void T93C46_Stop(struct sym_device *np, u_char *gpreg)
586 {
587 	*gpreg &= 0xef;
588 	OUTB(np, nc_gpreg, *gpreg);
589 	udelay(2);
590 
591 	T93C46_Clk(np, gpreg);
592 }
593 
594 /*
595  *  Send read command and address to NVRAM
596  */
597 static void T93C46_Send_Command(struct sym_device *np, u_short write_data,
598 				u_char *read_bit, u_char *gpreg)
599 {
600 	int x;
601 
602 	/* send 9 bits, start bit (1), command (2), address (6)  */
603 	for (x = 0; x < 9; x++)
604 		T93C46_Write_Bit(np, (u_char) (write_data >> (8 - x)), gpreg);
605 
606 	*read_bit = INB(np, nc_gpreg);
607 }
608 
609 /*
610  *  READ 2 bytes from the NVRAM
611  */
612 static void T93C46_Read_Word(struct sym_device *np,
613 		unsigned short *nvram_data, unsigned char *gpreg)
614 {
615 	int x;
616 	u_char read_bit;
617 
618 	*nvram_data = 0;
619 	for (x = 0; x < 16; x++) {
620 		T93C46_Read_Bit(np, &read_bit, gpreg);
621 
622 		if (read_bit & 0x01)
623 			*nvram_data |=  (0x01 << (15 - x));
624 		else
625 			*nvram_data &= ~(0x01 << (15 - x));
626 	}
627 }
628 
629 /*
630  *  Read Tekram NvRAM data.
631  */
632 static int T93C46_Read_Data(struct sym_device *np, unsigned short *data,
633 		int len, unsigned char *gpreg)
634 {
635 	int x;
636 
637 	for (x = 0; x < len; x++)  {
638 		unsigned char read_bit;
639 		/* output read command and address */
640 		T93C46_Send_Command(np, 0x180 | x, &read_bit, gpreg);
641 		if (read_bit & 0x01)
642 			return 1; /* Bad */
643 		T93C46_Read_Word(np, &data[x], gpreg);
644 		T93C46_Stop(np, gpreg);
645 	}
646 
647 	return 0;
648 }
649 
650 /*
651  *  Try reading 93C46 Tekram NVRAM.
652  */
653 static int sym_read_T93C46_nvram(struct sym_device *np, Tekram_nvram *nvram)
654 {
655 	u_char gpcntl, gpreg;
656 	u_char old_gpcntl, old_gpreg;
657 	int retv = 1;
658 
659 	/* save current state of GPCNTL and GPREG */
660 	old_gpreg	= INB(np, nc_gpreg);
661 	old_gpcntl	= INB(np, nc_gpcntl);
662 
663 	/* set up GPREG & GPCNTL to set GPIO0/1/2/4 in to known state, 0 in,
664 	   1/2/4 out */
665 	gpreg = old_gpreg & 0xe9;
666 	OUTB(np, nc_gpreg, gpreg);
667 	gpcntl = (old_gpcntl & 0xe9) | 0x09;
668 	OUTB(np, nc_gpcntl, gpcntl);
669 
670 	/* input all of NVRAM, 64 words */
671 	retv = T93C46_Read_Data(np, (u_short *) nvram,
672 				sizeof(*nvram) / sizeof(short), &gpreg);
673 
674 	/* return GPIO0/1/2/4 to original states after having accessed NVRAM */
675 	OUTB(np, nc_gpcntl, old_gpcntl);
676 	OUTB(np, nc_gpreg,  old_gpreg);
677 
678 	return retv;
679 }
680 
681 /*
682  *  Try reading Tekram NVRAM.
683  *  Return 0 if OK.
684  */
685 static int sym_read_Tekram_nvram (struct sym_device *np, Tekram_nvram *nvram)
686 {
687 	u_char *data = (u_char *) nvram;
688 	int len = sizeof(*nvram);
689 	u_short	csum;
690 	int x;
691 
692 	switch (np->device_id) {
693 	case PCI_DEVICE_ID_NCR_53C885:
694 	case PCI_DEVICE_ID_NCR_53C895:
695 	case PCI_DEVICE_ID_NCR_53C896:
696 		x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
697 					  data, len);
698 		break;
699 	case PCI_DEVICE_ID_NCR_53C875:
700 		x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
701 					  data, len);
702 		if (!x)
703 			break;
704 	default:
705 		x = sym_read_T93C46_nvram(np, nvram);
706 		break;
707 	}
708 	if (x)
709 		return 1;
710 
711 	/* verify checksum */
712 	for (x = 0, csum = 0; x < len - 1; x += 2)
713 		csum += data[x] + (data[x+1] << 8);
714 	if (csum != 0x1234)
715 		return 1;
716 
717 	return 0;
718 }
719 
720 #ifdef CONFIG_PARISC
721 /*
722  * Host firmware (PDC) keeps a table for altering SCSI capabilities.
723  * Many newer machines export one channel of 53c896 chip as SE, 50-pin HD.
724  * Also used for Multi-initiator SCSI clusters to set the SCSI Initiator ID.
725  */
726 static int sym_read_parisc_pdc(struct sym_device *np, struct pdc_initiator *pdc)
727 {
728 	struct hardware_path hwpath;
729 	get_pci_node_path(np->pdev, &hwpath);
730 	if (!pdc_get_initiator(&hwpath, pdc))
731 		return 0;
732 
733 	return SYM_PARISC_PDC;
734 }
735 #else
736 static int sym_read_parisc_pdc(struct sym_device *np, struct pdc_initiator *x)
737 {
738 	return 0;
739 }
740 #endif
741 
742 /*
743  *  Try reading Symbios or Tekram NVRAM
744  */
745 int sym_read_nvram(struct sym_device *np, struct sym_nvram *nvp)
746 {
747 	if (!sym_read_Symbios_nvram(np, &nvp->data.Symbios)) {
748 		nvp->type = SYM_SYMBIOS_NVRAM;
749 		sym_display_Symbios_nvram(np, &nvp->data.Symbios);
750 	} else if (!sym_read_Tekram_nvram(np, &nvp->data.Tekram)) {
751 		nvp->type = SYM_TEKRAM_NVRAM;
752 		sym_display_Tekram_nvram(np, &nvp->data.Tekram);
753 	} else {
754 		nvp->type = sym_read_parisc_pdc(np, &nvp->data.parisc);
755 	}
756 	return nvp->type;
757 }
758 
759 char *sym_nvram_type(struct sym_nvram *nvp)
760 {
761 	switch (nvp->type) {
762 	case SYM_SYMBIOS_NVRAM:
763 		return "Symbios NVRAM";
764 	case SYM_TEKRAM_NVRAM:
765 		return "Tekram NVRAM";
766 	case SYM_PARISC_PDC:
767 		return "PA-RISC Firmware";
768 	default:
769 		return "No NVRAM";
770 	}
771 }
772