1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Device driver for the SYMBIOS/LSILOGIC 53C8XX and 53C1010 family
4  * of PCI-SCSI IO processors.
5  *
6  * Copyright (C) 1999-2001  Gerard Roudier <groudier@free.fr>
7  *
8  * This driver is derived from the Linux sym53c8xx driver.
9  * Copyright (C) 1998-2000  Gerard Roudier
10  *
11  * The sym53c8xx driver is derived from the ncr53c8xx driver that had been
12  * a port of the FreeBSD ncr driver to Linux-1.2.13.
13  *
14  * The original ncr driver has been written for 386bsd and FreeBSD by
15  *         Wolfgang Stanglmeier        <wolf@cologne.de>
16  *         Stefan Esser                <se@mi.Uni-Koeln.de>
17  * Copyright (C) 1994  Wolfgang Stanglmeier
18  *
19  * Other major contributions:
20  *
21  * NVRAM detection and reading.
22  * Copyright (C) 1997 Richard Waltham <dormouse@farsrobt.demon.co.uk>
23  *
24  *-----------------------------------------------------------------------------
25  */
26 
27 #include "sym_glue.h"
28 #include "sym_nvram.h"
29 
30 #ifdef	SYM_CONF_DEBUG_NVRAM
31 static u_char Tekram_boot_delay[7] = {3, 5, 10, 20, 30, 60, 120};
32 #endif
33 
34 /*
35  *  Get host setup from NVRAM.
36  */
37 void sym_nvram_setup_host(struct Scsi_Host *shost, struct sym_hcb *np, struct sym_nvram *nvram)
38 {
39 	/*
40 	 *  Get parity checking, host ID, verbose mode
41 	 *  and miscellaneous host flags from NVRAM.
42 	 */
43 	switch (nvram->type) {
44 	case SYM_SYMBIOS_NVRAM:
45 		if (!(nvram->data.Symbios.flags & SYMBIOS_PARITY_ENABLE))
46 			np->rv_scntl0  &= ~0x0a;
47 		np->myaddr = nvram->data.Symbios.host_id & 0x0f;
48 		if (nvram->data.Symbios.flags & SYMBIOS_VERBOSE_MSGS)
49 			np->verbose += 1;
50 		if (nvram->data.Symbios.flags1 & SYMBIOS_SCAN_HI_LO)
51 			shost->reverse_ordering = 1;
52 		if (nvram->data.Symbios.flags2 & SYMBIOS_AVOID_BUS_RESET)
53 			np->usrflags |= SYM_AVOID_BUS_RESET;
54 		break;
55 	case SYM_TEKRAM_NVRAM:
56 		np->myaddr = nvram->data.Tekram.host_id & 0x0f;
57 		break;
58 #ifdef CONFIG_PARISC
59 	case SYM_PARISC_PDC:
60 		if (nvram->data.parisc.host_id != -1)
61 			np->myaddr = nvram->data.parisc.host_id;
62 		if (nvram->data.parisc.factor != -1)
63 			np->minsync = nvram->data.parisc.factor;
64 		if (nvram->data.parisc.width != -1)
65 			np->maxwide = nvram->data.parisc.width;
66 		switch (nvram->data.parisc.mode) {
67 			case 0: np->scsi_mode = SMODE_SE; break;
68 			case 1: np->scsi_mode = SMODE_HVD; break;
69 			case 2: np->scsi_mode = SMODE_LVD; break;
70 			default: break;
71 		}
72 #endif
73 	default:
74 		break;
75 	}
76 }
77 
78 /*
79  *  Get target set-up from Symbios format NVRAM.
80  */
81 static void
82 sym_Symbios_setup_target(struct sym_tcb *tp, int target, Symbios_nvram *nvram)
83 {
84 	Symbios_target *tn = &nvram->target[target];
85 
86 	if (!(tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED))
87 		tp->usrtags = 0;
88 	if (!(tn->flags & SYMBIOS_DISCONNECT_ENABLE))
89 		tp->usrflags &= ~SYM_DISC_ENABLED;
90 	if (!(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME))
91 		tp->usrflags |= SYM_SCAN_BOOT_DISABLED;
92 	if (!(tn->flags & SYMBIOS_SCAN_LUNS))
93 		tp->usrflags |= SYM_SCAN_LUNS_DISABLED;
94 	tp->usr_period = (tn->sync_period + 3) / 4;
95 	tp->usr_width = (tn->bus_width == 0x8) ? 0 : 1;
96 }
97 
98 static const unsigned char Tekram_sync[16] = {
99 	25, 31, 37, 43, 50, 62, 75, 125, 12, 15, 18, 21, 6, 7, 9, 10
100 };
101 
102 /*
103  *  Get target set-up from Tekram format NVRAM.
104  */
105 static void
106 sym_Tekram_setup_target(struct sym_tcb *tp, int target, Tekram_nvram *nvram)
107 {
108 	struct Tekram_target *tn = &nvram->target[target];
109 
110 	if (tn->flags & TEKRAM_TAGGED_COMMANDS) {
111 		tp->usrtags = 2 << nvram->max_tags_index;
112 	}
113 
114 	if (tn->flags & TEKRAM_DISCONNECT_ENABLE)
115 		tp->usrflags |= SYM_DISC_ENABLED;
116 
117 	if (tn->flags & TEKRAM_SYNC_NEGO)
118 		tp->usr_period = Tekram_sync[tn->sync_index & 0xf];
119 	tp->usr_width = (tn->flags & TEKRAM_WIDE_NEGO) ? 1 : 0;
120 }
121 
122 /*
123  *  Get target setup from NVRAM.
124  */
125 void sym_nvram_setup_target(struct sym_tcb *tp, int target, struct sym_nvram *nvp)
126 {
127 	switch (nvp->type) {
128 	case SYM_SYMBIOS_NVRAM:
129 		sym_Symbios_setup_target(tp, target, &nvp->data.Symbios);
130 		break;
131 	case SYM_TEKRAM_NVRAM:
132 		sym_Tekram_setup_target(tp, target, &nvp->data.Tekram);
133 		break;
134 	default:
135 		break;
136 	}
137 }
138 
139 #ifdef	SYM_CONF_DEBUG_NVRAM
140 /*
141  *  Dump Symbios format NVRAM for debugging purpose.
142  */
143 static void sym_display_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram)
144 {
145 	int i;
146 
147 	/* display Symbios nvram host data */
148 	printf("%s: HOST ID=%d%s%s%s%s%s%s\n",
149 		sym_name(np), nvram->host_id & 0x0f,
150 		(nvram->flags  & SYMBIOS_SCAM_ENABLE)	? " SCAM"	:"",
151 		(nvram->flags  & SYMBIOS_PARITY_ENABLE)	? " PARITY"	:"",
152 		(nvram->flags  & SYMBIOS_VERBOSE_MSGS)	? " VERBOSE"	:"",
153 		(nvram->flags  & SYMBIOS_CHS_MAPPING)	? " CHS_ALT"	:"",
154 		(nvram->flags2 & SYMBIOS_AVOID_BUS_RESET)?" NO_RESET"	:"",
155 		(nvram->flags1 & SYMBIOS_SCAN_HI_LO)	? " HI_LO"	:"");
156 
157 	/* display Symbios nvram drive data */
158 	for (i = 0 ; i < 15 ; i++) {
159 		struct Symbios_target *tn = &nvram->target[i];
160 		printf("%s-%d:%s%s%s%s WIDTH=%d SYNC=%d TMO=%d\n",
161 		sym_name(np), i,
162 		(tn->flags & SYMBIOS_DISCONNECT_ENABLE)	? " DISC"	: "",
163 		(tn->flags & SYMBIOS_SCAN_AT_BOOT_TIME)	? " SCAN_BOOT"	: "",
164 		(tn->flags & SYMBIOS_SCAN_LUNS)		? " SCAN_LUNS"	: "",
165 		(tn->flags & SYMBIOS_QUEUE_TAGS_ENABLED)? " TCQ"	: "",
166 		tn->bus_width,
167 		tn->sync_period / 4,
168 		tn->timeout);
169 	}
170 }
171 
172 /*
173  *  Dump TEKRAM format NVRAM for debugging purpose.
174  */
175 static void sym_display_Tekram_nvram(struct sym_device *np, Tekram_nvram *nvram)
176 {
177 	int i, tags, boot_delay;
178 	char *rem;
179 
180 	/* display Tekram nvram host data */
181 	tags = 2 << nvram->max_tags_index;
182 	boot_delay = 0;
183 	if (nvram->boot_delay_index < 6)
184 		boot_delay = Tekram_boot_delay[nvram->boot_delay_index];
185 	switch ((nvram->flags & TEKRAM_REMOVABLE_FLAGS) >> 6) {
186 	default:
187 	case 0:	rem = "";			break;
188 	case 1: rem = " REMOVABLE=boot device";	break;
189 	case 2: rem = " REMOVABLE=all";		break;
190 	}
191 
192 	printf("%s: HOST ID=%d%s%s%s%s%s%s%s%s%s BOOT DELAY=%d tags=%d\n",
193 		sym_name(np), nvram->host_id & 0x0f,
194 		(nvram->flags1 & SYMBIOS_SCAM_ENABLE)	? " SCAM"	:"",
195 		(nvram->flags & TEKRAM_MORE_THAN_2_DRIVES) ? " >2DRIVES":"",
196 		(nvram->flags & TEKRAM_DRIVES_SUP_1GB)	? " >1GB"	:"",
197 		(nvram->flags & TEKRAM_RESET_ON_POWER_ON) ? " RESET"	:"",
198 		(nvram->flags & TEKRAM_ACTIVE_NEGATION)	? " ACT_NEG"	:"",
199 		(nvram->flags & TEKRAM_IMMEDIATE_SEEK)	? " IMM_SEEK"	:"",
200 		(nvram->flags & TEKRAM_SCAN_LUNS)	? " SCAN_LUNS"	:"",
201 		(nvram->flags1 & TEKRAM_F2_F6_ENABLED)	? " F2_F6"	:"",
202 		rem, boot_delay, tags);
203 
204 	/* display Tekram nvram drive data */
205 	for (i = 0; i <= 15; i++) {
206 		int sync, j;
207 		struct Tekram_target *tn = &nvram->target[i];
208 		j = tn->sync_index & 0xf;
209 		sync = Tekram_sync[j];
210 		printf("%s-%d:%s%s%s%s%s%s PERIOD=%d\n",
211 		sym_name(np), i,
212 		(tn->flags & TEKRAM_PARITY_CHECK)	? " PARITY"	: "",
213 		(tn->flags & TEKRAM_SYNC_NEGO)		? " SYNC"	: "",
214 		(tn->flags & TEKRAM_DISCONNECT_ENABLE)	? " DISC"	: "",
215 		(tn->flags & TEKRAM_START_CMD)		? " START"	: "",
216 		(tn->flags & TEKRAM_TAGGED_COMMANDS)	? " TCQ"	: "",
217 		(tn->flags & TEKRAM_WIDE_NEGO)		? " WIDE"	: "",
218 		sync);
219 	}
220 }
221 #else
222 static void sym_display_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram) { (void)np; (void)nvram; }
223 static void sym_display_Tekram_nvram(struct sym_device *np, Tekram_nvram *nvram) { (void)np; (void)nvram; }
224 #endif	/* SYM_CONF_DEBUG_NVRAM */
225 
226 
227 /*
228  *  24C16 EEPROM reading.
229  *
230  *  GPIO0 - data in/data out
231  *  GPIO1 - clock
232  *  Symbios NVRAM wiring now also used by Tekram.
233  */
234 
235 #define SET_BIT 0
236 #define CLR_BIT 1
237 #define SET_CLK 2
238 #define CLR_CLK 3
239 
240 /*
241  *  Set/clear data/clock bit in GPIO0
242  */
243 static void S24C16_set_bit(struct sym_device *np, u_char write_bit, u_char *gpreg,
244 			  int bit_mode)
245 {
246 	udelay(5);
247 	switch (bit_mode) {
248 	case SET_BIT:
249 		*gpreg |= write_bit;
250 		break;
251 	case CLR_BIT:
252 		*gpreg &= 0xfe;
253 		break;
254 	case SET_CLK:
255 		*gpreg |= 0x02;
256 		break;
257 	case CLR_CLK:
258 		*gpreg &= 0xfd;
259 		break;
260 
261 	}
262 	OUTB(np, nc_gpreg, *gpreg);
263 	INB(np, nc_mbox1);
264 	udelay(5);
265 }
266 
267 /*
268  *  Send START condition to NVRAM to wake it up.
269  */
270 static void S24C16_start(struct sym_device *np, u_char *gpreg)
271 {
272 	S24C16_set_bit(np, 1, gpreg, SET_BIT);
273 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
274 	S24C16_set_bit(np, 0, gpreg, CLR_BIT);
275 	S24C16_set_bit(np, 0, gpreg, CLR_CLK);
276 }
277 
278 /*
279  *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZzzzz!!
280  */
281 static void S24C16_stop(struct sym_device *np, u_char *gpreg)
282 {
283 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
284 	S24C16_set_bit(np, 1, gpreg, SET_BIT);
285 }
286 
287 /*
288  *  Read or write a bit to the NVRAM,
289  *  read if GPIO0 input else write if GPIO0 output
290  */
291 static void S24C16_do_bit(struct sym_device *np, u_char *read_bit, u_char write_bit,
292 			 u_char *gpreg)
293 {
294 	S24C16_set_bit(np, write_bit, gpreg, SET_BIT);
295 	S24C16_set_bit(np, 0, gpreg, SET_CLK);
296 	if (read_bit)
297 		*read_bit = INB(np, nc_gpreg);
298 	S24C16_set_bit(np, 0, gpreg, CLR_CLK);
299 	S24C16_set_bit(np, 0, gpreg, CLR_BIT);
300 }
301 
302 /*
303  *  Output an ACK to the NVRAM after reading,
304  *  change GPIO0 to output and when done back to an input
305  */
306 static void S24C16_write_ack(struct sym_device *np, u_char write_bit, u_char *gpreg,
307 			    u_char *gpcntl)
308 {
309 	OUTB(np, nc_gpcntl, *gpcntl & 0xfe);
310 	S24C16_do_bit(np, NULL, write_bit, gpreg);
311 	OUTB(np, nc_gpcntl, *gpcntl);
312 }
313 
314 /*
315  *  Input an ACK from NVRAM after writing,
316  *  change GPIO0 to input and when done back to an output
317  */
318 static void S24C16_read_ack(struct sym_device *np, u_char *read_bit, u_char *gpreg,
319 			   u_char *gpcntl)
320 {
321 	OUTB(np, nc_gpcntl, *gpcntl | 0x01);
322 	S24C16_do_bit(np, read_bit, 1, gpreg);
323 	OUTB(np, nc_gpcntl, *gpcntl);
324 }
325 
326 /*
327  *  WRITE a byte to the NVRAM and then get an ACK to see it was accepted OK,
328  *  GPIO0 must already be set as an output
329  */
330 static void S24C16_write_byte(struct sym_device *np, u_char *ack_data, u_char write_data,
331 			     u_char *gpreg, u_char *gpcntl)
332 {
333 	int x;
334 
335 	for (x = 0; x < 8; x++)
336 		S24C16_do_bit(np, NULL, (write_data >> (7 - x)) & 0x01, gpreg);
337 
338 	S24C16_read_ack(np, ack_data, gpreg, gpcntl);
339 }
340 
341 /*
342  *  READ a byte from the NVRAM and then send an ACK to say we have got it,
343  *  GPIO0 must already be set as an input
344  */
345 static void S24C16_read_byte(struct sym_device *np, u_char *read_data, u_char ack_data,
346 			    u_char *gpreg, u_char *gpcntl)
347 {
348 	int x;
349 	u_char read_bit;
350 
351 	*read_data = 0;
352 	for (x = 0; x < 8; x++) {
353 		S24C16_do_bit(np, &read_bit, 1, gpreg);
354 		*read_data |= ((read_bit & 0x01) << (7 - x));
355 	}
356 
357 	S24C16_write_ack(np, ack_data, gpreg, gpcntl);
358 }
359 
360 #ifdef SYM_CONF_NVRAM_WRITE_SUPPORT
361 /*
362  *  Write 'len' bytes starting at 'offset'.
363  */
364 static int sym_write_S24C16_nvram(struct sym_device *np, int offset,
365 		u_char *data, int len)
366 {
367 	u_char	gpcntl, gpreg;
368 	u_char	old_gpcntl, old_gpreg;
369 	u_char	ack_data;
370 	int	x;
371 
372 	/* save current state of GPCNTL and GPREG */
373 	old_gpreg	= INB(np, nc_gpreg);
374 	old_gpcntl	= INB(np, nc_gpcntl);
375 	gpcntl		= old_gpcntl & 0x1c;
376 
377 	/* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
378 	OUTB(np, nc_gpreg,  old_gpreg);
379 	OUTB(np, nc_gpcntl, gpcntl);
380 
381 	/* this is to set NVRAM into a known state with GPIO0/1 both low */
382 	gpreg = old_gpreg;
383 	S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
384 	S24C16_set_bit(np, 0, &gpreg, CLR_BIT);
385 
386 	/* now set NVRAM inactive with GPIO0/1 both high */
387 	S24C16_stop(np, &gpreg);
388 
389 	/* NVRAM has to be written in segments of 16 bytes */
390 	for (x = 0; x < len ; x += 16) {
391 		do {
392 			S24C16_start(np, &gpreg);
393 			S24C16_write_byte(np, &ack_data,
394 					  0xa0 | (((offset+x) >> 7) & 0x0e),
395 					  &gpreg, &gpcntl);
396 		} while (ack_data & 0x01);
397 
398 		S24C16_write_byte(np, &ack_data, (offset+x) & 0xff,
399 				  &gpreg, &gpcntl);
400 
401 		for (y = 0; y < 16; y++)
402 			S24C16_write_byte(np, &ack_data, data[x+y],
403 					  &gpreg, &gpcntl);
404 		S24C16_stop(np, &gpreg);
405 	}
406 
407 	/* return GPIO0/1 to original states after having accessed NVRAM */
408 	OUTB(np, nc_gpcntl, old_gpcntl);
409 	OUTB(np, nc_gpreg,  old_gpreg);
410 
411 	return 0;
412 }
413 #endif /* SYM_CONF_NVRAM_WRITE_SUPPORT */
414 
415 /*
416  *  Read 'len' bytes starting at 'offset'.
417  */
418 static int sym_read_S24C16_nvram(struct sym_device *np, int offset, u_char *data, int len)
419 {
420 	u_char	gpcntl, gpreg;
421 	u_char	old_gpcntl, old_gpreg;
422 	u_char	ack_data;
423 	int	retv = 1;
424 	int	x;
425 
426 	/* save current state of GPCNTL and GPREG */
427 	old_gpreg	= INB(np, nc_gpreg);
428 	old_gpcntl	= INB(np, nc_gpcntl);
429 	gpcntl		= old_gpcntl & 0x1c;
430 
431 	/* set up GPREG & GPCNTL to set GPIO0 and GPIO1 in to known state */
432 	OUTB(np, nc_gpreg,  old_gpreg);
433 	OUTB(np, nc_gpcntl, gpcntl);
434 
435 	/* this is to set NVRAM into a known state with GPIO0/1 both low */
436 	gpreg = old_gpreg;
437 	S24C16_set_bit(np, 0, &gpreg, CLR_CLK);
438 	S24C16_set_bit(np, 0, &gpreg, CLR_BIT);
439 
440 	/* now set NVRAM inactive with GPIO0/1 both high */
441 	S24C16_stop(np, &gpreg);
442 
443 	/* activate NVRAM */
444 	S24C16_start(np, &gpreg);
445 
446 	/* write device code and random address MSB */
447 	S24C16_write_byte(np, &ack_data,
448 		0xa0 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
449 	if (ack_data & 0x01)
450 		goto out;
451 
452 	/* write random address LSB */
453 	S24C16_write_byte(np, &ack_data,
454 		offset & 0xff, &gpreg, &gpcntl);
455 	if (ack_data & 0x01)
456 		goto out;
457 
458 	/* regenerate START state to set up for reading */
459 	S24C16_start(np, &gpreg);
460 
461 	/* rewrite device code and address MSB with read bit set (lsb = 0x01) */
462 	S24C16_write_byte(np, &ack_data,
463 		0xa1 | ((offset >> 7) & 0x0e), &gpreg, &gpcntl);
464 	if (ack_data & 0x01)
465 		goto out;
466 
467 	/* now set up GPIO0 for inputting data */
468 	gpcntl |= 0x01;
469 	OUTB(np, nc_gpcntl, gpcntl);
470 
471 	/* input all requested data - only part of total NVRAM */
472 	for (x = 0; x < len; x++)
473 		S24C16_read_byte(np, &data[x], (x == (len-1)), &gpreg, &gpcntl);
474 
475 	/* finally put NVRAM back in inactive mode */
476 	gpcntl &= 0xfe;
477 	OUTB(np, nc_gpcntl, gpcntl);
478 	S24C16_stop(np, &gpreg);
479 	retv = 0;
480 out:
481 	/* return GPIO0/1 to original states after having accessed NVRAM */
482 	OUTB(np, nc_gpcntl, old_gpcntl);
483 	OUTB(np, nc_gpreg,  old_gpreg);
484 
485 	return retv;
486 }
487 
488 #undef SET_BIT
489 #undef CLR_BIT
490 #undef SET_CLK
491 #undef CLR_CLK
492 
493 /*
494  *  Try reading Symbios NVRAM.
495  *  Return 0 if OK.
496  */
497 static int sym_read_Symbios_nvram(struct sym_device *np, Symbios_nvram *nvram)
498 {
499 	static u_char Symbios_trailer[6] = {0xfe, 0xfe, 0, 0, 0, 0};
500 	u_char *data = (u_char *) nvram;
501 	int len  = sizeof(*nvram);
502 	u_short	csum;
503 	int x;
504 
505 	/* probe the 24c16 and read the SYMBIOS 24c16 area */
506 	if (sym_read_S24C16_nvram (np, SYMBIOS_NVRAM_ADDRESS, data, len))
507 		return 1;
508 
509 	/* check valid NVRAM signature, verify byte count and checksum */
510 	if (nvram->type != 0 ||
511 	    memcmp(nvram->trailer, Symbios_trailer, 6) ||
512 	    nvram->byte_count != len - 12)
513 		return 1;
514 
515 	/* verify checksum */
516 	for (x = 6, csum = 0; x < len - 6; x++)
517 		csum += data[x];
518 	if (csum != nvram->checksum)
519 		return 1;
520 
521 	return 0;
522 }
523 
524 /*
525  *  93C46 EEPROM reading.
526  *
527  *  GPIO0 - data in
528  *  GPIO1 - data out
529  *  GPIO2 - clock
530  *  GPIO4 - chip select
531  *
532  *  Used by Tekram.
533  */
534 
535 /*
536  *  Pulse clock bit in GPIO0
537  */
538 static void T93C46_Clk(struct sym_device *np, u_char *gpreg)
539 {
540 	OUTB(np, nc_gpreg, *gpreg | 0x04);
541 	INB(np, nc_mbox1);
542 	udelay(2);
543 	OUTB(np, nc_gpreg, *gpreg);
544 }
545 
546 /*
547  *  Read bit from NVRAM
548  */
549 static void T93C46_Read_Bit(struct sym_device *np, u_char *read_bit, u_char *gpreg)
550 {
551 	udelay(2);
552 	T93C46_Clk(np, gpreg);
553 	*read_bit = INB(np, nc_gpreg);
554 }
555 
556 /*
557  *  Write bit to GPIO0
558  */
559 static void T93C46_Write_Bit(struct sym_device *np, u_char write_bit, u_char *gpreg)
560 {
561 	if (write_bit & 0x01)
562 		*gpreg |= 0x02;
563 	else
564 		*gpreg &= 0xfd;
565 
566 	*gpreg |= 0x10;
567 
568 	OUTB(np, nc_gpreg, *gpreg);
569 	INB(np, nc_mbox1);
570 	udelay(2);
571 
572 	T93C46_Clk(np, gpreg);
573 }
574 
575 /*
576  *  Send STOP condition to NVRAM - puts NVRAM to sleep... ZZZzzz!!
577  */
578 static void T93C46_Stop(struct sym_device *np, u_char *gpreg)
579 {
580 	*gpreg &= 0xef;
581 	OUTB(np, nc_gpreg, *gpreg);
582 	INB(np, nc_mbox1);
583 	udelay(2);
584 
585 	T93C46_Clk(np, gpreg);
586 }
587 
588 /*
589  *  Send read command and address to NVRAM
590  */
591 static void T93C46_Send_Command(struct sym_device *np, u_short write_data,
592 				u_char *read_bit, u_char *gpreg)
593 {
594 	int x;
595 
596 	/* send 9 bits, start bit (1), command (2), address (6)  */
597 	for (x = 0; x < 9; x++)
598 		T93C46_Write_Bit(np, (u_char) (write_data >> (8 - x)), gpreg);
599 
600 	*read_bit = INB(np, nc_gpreg);
601 }
602 
603 /*
604  *  READ 2 bytes from the NVRAM
605  */
606 static void T93C46_Read_Word(struct sym_device *np,
607 		unsigned short *nvram_data, unsigned char *gpreg)
608 {
609 	int x;
610 	u_char read_bit;
611 
612 	*nvram_data = 0;
613 	for (x = 0; x < 16; x++) {
614 		T93C46_Read_Bit(np, &read_bit, gpreg);
615 
616 		if (read_bit & 0x01)
617 			*nvram_data |=  (0x01 << (15 - x));
618 		else
619 			*nvram_data &= ~(0x01 << (15 - x));
620 	}
621 }
622 
623 /*
624  *  Read Tekram NvRAM data.
625  */
626 static int T93C46_Read_Data(struct sym_device *np, unsigned short *data,
627 		int len, unsigned char *gpreg)
628 {
629 	int x;
630 
631 	for (x = 0; x < len; x++)  {
632 		unsigned char read_bit;
633 		/* output read command and address */
634 		T93C46_Send_Command(np, 0x180 | x, &read_bit, gpreg);
635 		if (read_bit & 0x01)
636 			return 1; /* Bad */
637 		T93C46_Read_Word(np, &data[x], gpreg);
638 		T93C46_Stop(np, gpreg);
639 	}
640 
641 	return 0;
642 }
643 
644 /*
645  *  Try reading 93C46 Tekram NVRAM.
646  */
647 static int sym_read_T93C46_nvram(struct sym_device *np, Tekram_nvram *nvram)
648 {
649 	u_char gpcntl, gpreg;
650 	u_char old_gpcntl, old_gpreg;
651 	int retv;
652 
653 	/* save current state of GPCNTL and GPREG */
654 	old_gpreg	= INB(np, nc_gpreg);
655 	old_gpcntl	= INB(np, nc_gpcntl);
656 
657 	/* set up GPREG & GPCNTL to set GPIO0/1/2/4 in to known state, 0 in,
658 	   1/2/4 out */
659 	gpreg = old_gpreg & 0xe9;
660 	OUTB(np, nc_gpreg, gpreg);
661 	gpcntl = (old_gpcntl & 0xe9) | 0x09;
662 	OUTB(np, nc_gpcntl, gpcntl);
663 
664 	/* input all of NVRAM, 64 words */
665 	retv = T93C46_Read_Data(np, (u_short *) nvram,
666 				sizeof(*nvram) / sizeof(short), &gpreg);
667 
668 	/* return GPIO0/1/2/4 to original states after having accessed NVRAM */
669 	OUTB(np, nc_gpcntl, old_gpcntl);
670 	OUTB(np, nc_gpreg,  old_gpreg);
671 
672 	return retv;
673 }
674 
675 /*
676  *  Try reading Tekram NVRAM.
677  *  Return 0 if OK.
678  */
679 static int sym_read_Tekram_nvram (struct sym_device *np, Tekram_nvram *nvram)
680 {
681 	u_char *data = (u_char *) nvram;
682 	int len = sizeof(*nvram);
683 	u_short	csum;
684 	int x;
685 
686 	switch (np->pdev->device) {
687 	case PCI_DEVICE_ID_NCR_53C885:
688 	case PCI_DEVICE_ID_NCR_53C895:
689 	case PCI_DEVICE_ID_NCR_53C896:
690 		x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
691 					  data, len);
692 		break;
693 	case PCI_DEVICE_ID_NCR_53C875:
694 		x = sym_read_S24C16_nvram(np, TEKRAM_24C16_NVRAM_ADDRESS,
695 					  data, len);
696 		if (!x)
697 			break;
698 		fallthrough;
699 	default:
700 		x = sym_read_T93C46_nvram(np, nvram);
701 		break;
702 	}
703 	if (x)
704 		return 1;
705 
706 	/* verify checksum */
707 	for (x = 0, csum = 0; x < len - 1; x += 2)
708 		csum += data[x] + (data[x+1] << 8);
709 	if (csum != 0x1234)
710 		return 1;
711 
712 	return 0;
713 }
714 
715 #ifdef CONFIG_PARISC
716 /*
717  * Host firmware (PDC) keeps a table for altering SCSI capabilities.
718  * Many newer machines export one channel of 53c896 chip as SE, 50-pin HD.
719  * Also used for Multi-initiator SCSI clusters to set the SCSI Initiator ID.
720  */
721 static int sym_read_parisc_pdc(struct sym_device *np, struct pdc_initiator *pdc)
722 {
723 	struct hardware_path hwpath;
724 	get_pci_node_path(np->pdev, &hwpath);
725 	if (!pdc_get_initiator(&hwpath, pdc))
726 		return 0;
727 
728 	return SYM_PARISC_PDC;
729 }
730 #else
731 static inline int sym_read_parisc_pdc(struct sym_device *np,
732 					struct pdc_initiator *x)
733 {
734 	return 0;
735 }
736 #endif
737 
738 /*
739  *  Try reading Symbios or Tekram NVRAM
740  */
741 int sym_read_nvram(struct sym_device *np, struct sym_nvram *nvp)
742 {
743 	if (!sym_read_Symbios_nvram(np, &nvp->data.Symbios)) {
744 		nvp->type = SYM_SYMBIOS_NVRAM;
745 		sym_display_Symbios_nvram(np, &nvp->data.Symbios);
746 	} else if (!sym_read_Tekram_nvram(np, &nvp->data.Tekram)) {
747 		nvp->type = SYM_TEKRAM_NVRAM;
748 		sym_display_Tekram_nvram(np, &nvp->data.Tekram);
749 	} else {
750 		nvp->type = sym_read_parisc_pdc(np, &nvp->data.parisc);
751 	}
752 	return nvp->type;
753 }
754 
755 char *sym_nvram_type(struct sym_nvram *nvp)
756 {
757 	switch (nvp->type) {
758 	case SYM_SYMBIOS_NVRAM:
759 		return "Symbios NVRAM";
760 	case SYM_TEKRAM_NVRAM:
761 		return "Tekram NVRAM";
762 	case SYM_PARISC_PDC:
763 		return "PA-RISC Firmware";
764 	default:
765 		return "No NVRAM";
766 	}
767 }
768