xref: /freebsd/sys/dev/cfi/cfi_core.c (revision 5686c6c38a3e1cc78804eaf5f880bda23dcf592f)
1 /*-
2  * Copyright (c) 2007, Juniper Networks, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the author nor the names of any co-contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_cfi.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/endian.h>
40 #include <sys/kenv.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/module.h>
44 #include <sys/rman.h>
45 #include <sys/sysctl.h>
46 
47 #include <machine/bus.h>
48 
49 #include <dev/cfi/cfi_reg.h>
50 #include <dev/cfi/cfi_var.h>
51 
52 extern struct cdevsw cfi_cdevsw;
53 
54 char cfi_driver_name[] = "cfi";
55 devclass_t cfi_devclass;
56 devclass_t cfi_diskclass;
57 
58 uint32_t
59 cfi_read_raw(struct cfi_softc *sc, u_int ofs)
60 {
61 	uint32_t val;
62 
63 	ofs &= ~(sc->sc_width - 1);
64 	switch (sc->sc_width) {
65 	case 1:
66 		val = bus_space_read_1(sc->sc_tag, sc->sc_handle, ofs);
67 		break;
68 	case 2:
69 		val = bus_space_read_2(sc->sc_tag, sc->sc_handle, ofs);
70 		break;
71 	case 4:
72 		val = bus_space_read_4(sc->sc_tag, sc->sc_handle, ofs);
73 		break;
74 	default:
75 		val = ~0;
76 		break;
77 	}
78 	return (val);
79 }
80 
81 uint32_t
82 cfi_read(struct cfi_softc *sc, u_int ofs)
83 {
84 	uint32_t val;
85 	uint16_t sval;
86 
87 	ofs &= ~(sc->sc_width - 1);
88 	switch (sc->sc_width) {
89 	case 1:
90 		val = bus_space_read_1(sc->sc_tag, sc->sc_handle, ofs);
91 		break;
92 	case 2:
93 		sval = bus_space_read_2(sc->sc_tag, sc->sc_handle, ofs);
94 		val = le16toh(sval);
95 		break;
96 	case 4:
97 		val = bus_space_read_4(sc->sc_tag, sc->sc_handle, ofs);
98 		val = le32toh(val);
99 		break;
100 	default:
101 		val = ~0;
102 		break;
103 	}
104 	return (val);
105 }
106 
107 static void
108 cfi_write(struct cfi_softc *sc, u_int ofs, u_int val)
109 {
110 
111 	ofs &= ~(sc->sc_width - 1);
112 	switch (sc->sc_width) {
113 	case 1:
114 		bus_space_write_1(sc->sc_tag, sc->sc_handle, ofs, val);
115 		break;
116 	case 2:
117 		bus_space_write_2(sc->sc_tag, sc->sc_handle, ofs, htole16(val));
118 		break;
119 	case 4:
120 		bus_space_write_4(sc->sc_tag, sc->sc_handle, ofs, htole32(val));
121 		break;
122 	}
123 }
124 
125 uint8_t
126 cfi_read_qry(struct cfi_softc *sc, u_int ofs)
127 {
128 	uint8_t val;
129 
130 	cfi_write(sc, CFI_QRY_CMD_ADDR * sc->sc_width, CFI_QRY_CMD_DATA);
131 	val = cfi_read(sc, ofs * sc->sc_width);
132 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
133 	return (val);
134 }
135 
136 static void
137 cfi_amd_write(struct cfi_softc *sc, u_int ofs, u_int addr, u_int data)
138 {
139 
140 	cfi_write(sc, ofs + AMD_ADDR_START, CFI_AMD_UNLOCK);
141 	cfi_write(sc, ofs + AMD_ADDR_ACK, CFI_AMD_UNLOCK_ACK);
142 	cfi_write(sc, ofs + addr, data);
143 }
144 
145 static char *
146 cfi_fmtsize(uint32_t sz)
147 {
148 	static char buf[8];
149 	static const char *sfx[] = { "", "K", "M", "G" };
150 	int sfxidx;
151 
152 	sfxidx = 0;
153 	while (sfxidx < 3 && sz > 1023) {
154 		sz /= 1024;
155 		sfxidx++;
156 	}
157 
158 	sprintf(buf, "%u%sB", sz, sfx[sfxidx]);
159 	return (buf);
160 }
161 
162 int
163 cfi_probe(device_t dev)
164 {
165 	char desc[80];
166 	struct cfi_softc *sc;
167 	char *vend_str;
168 	int error;
169 	uint16_t iface, vend;
170 
171 	sc = device_get_softc(dev);
172 	sc->sc_dev = dev;
173 
174 	sc->sc_rid = 0;
175 	sc->sc_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->sc_rid,
176 	    RF_ACTIVE);
177 	if (sc->sc_res == NULL)
178 		return (ENXIO);
179 
180 	sc->sc_tag = rman_get_bustag(sc->sc_res);
181 	sc->sc_handle = rman_get_bushandle(sc->sc_res);
182 
183 	if (sc->sc_width == 0) {
184 		sc->sc_width = 1;
185 		while (sc->sc_width <= 4) {
186 			if (cfi_read_qry(sc, CFI_QRY_IDENT) == 'Q')
187 				break;
188 			sc->sc_width <<= 1;
189 		}
190 	} else if (cfi_read_qry(sc, CFI_QRY_IDENT) != 'Q') {
191 		error = ENXIO;
192 		goto out;
193 	}
194 	if (sc->sc_width > 4) {
195 		error = ENXIO;
196 		goto out;
197 	}
198 
199 	/* We got a Q. Check if we also have the R and the Y. */
200 	if (cfi_read_qry(sc, CFI_QRY_IDENT + 1) != 'R' ||
201 	    cfi_read_qry(sc, CFI_QRY_IDENT + 2) != 'Y') {
202 		error = ENXIO;
203 		goto out;
204 	}
205 
206 	/* Get the vendor and command set. */
207 	vend = cfi_read_qry(sc, CFI_QRY_VEND) |
208 	    (cfi_read_qry(sc, CFI_QRY_VEND + 1) << 8);
209 
210 	sc->sc_cmdset = vend;
211 
212 	switch (vend) {
213 	case CFI_VEND_AMD_ECS:
214 	case CFI_VEND_AMD_SCS:
215 		vend_str = "AMD/Fujitsu";
216 		break;
217 	case CFI_VEND_INTEL_ECS:
218 		vend_str = "Intel/Sharp";
219 		break;
220 	case CFI_VEND_INTEL_SCS:
221 		vend_str = "Intel";
222 		break;
223 	case CFI_VEND_MITSUBISHI_ECS:
224 	case CFI_VEND_MITSUBISHI_SCS:
225 		vend_str = "Mitsubishi";
226 		break;
227 	default:
228 		vend_str = "Unknown vendor";
229 		break;
230 	}
231 
232 	/* Get the device size. */
233 	sc->sc_size = 1U << cfi_read_qry(sc, CFI_QRY_SIZE);
234 
235 	/* Sanity-check the I/F */
236 	iface = cfi_read_qry(sc, CFI_QRY_IFACE) |
237 	    (cfi_read_qry(sc, CFI_QRY_IFACE + 1) << 8);
238 
239 	/*
240 	 * Adding 1 to iface will give us a bit-wise "switch"
241 	 * that allows us to test for the interface width by
242 	 * testing a single bit.
243 	 */
244 	iface++;
245 
246 	error = (iface & sc->sc_width) ? 0 : EINVAL;
247 	if (error)
248 		goto out;
249 
250 	snprintf(desc, sizeof(desc), "%s - %s", vend_str,
251 	    cfi_fmtsize(sc->sc_size));
252 	device_set_desc_copy(dev, desc);
253 
254  out:
255 	bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid, sc->sc_res);
256 	return (error);
257 }
258 
259 int
260 cfi_attach(device_t dev)
261 {
262 	struct cfi_softc *sc;
263 	u_int blksz, blocks;
264 	u_int r, u;
265 #ifdef CFI_SUPPORT_STRATAFLASH
266 	uint64_t ppr;
267 	char name[KENV_MNAMELEN], value[32];
268 #endif
269 
270 	sc = device_get_softc(dev);
271 	sc->sc_dev = dev;
272 
273 	sc->sc_rid = 0;
274 	sc->sc_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->sc_rid,
275 	    RF_ACTIVE);
276 	if (sc->sc_res == NULL)
277 		return (ENXIO);
278 
279 	sc->sc_tag = rman_get_bustag(sc->sc_res);
280 	sc->sc_handle = rman_get_bushandle(sc->sc_res);
281 
282 	/* Get time-out values for erase and write. */
283 	sc->sc_write_timeout = 1 << cfi_read_qry(sc, CFI_QRY_TTO_WRITE);
284 	sc->sc_erase_timeout = 1 << cfi_read_qry(sc, CFI_QRY_TTO_ERASE);
285 	sc->sc_write_timeout *= 1 << cfi_read_qry(sc, CFI_QRY_MTO_WRITE);
286 	sc->sc_erase_timeout *= 1 << cfi_read_qry(sc, CFI_QRY_MTO_ERASE);
287 
288 	/* Get erase regions. */
289 	sc->sc_regions = cfi_read_qry(sc, CFI_QRY_NREGIONS);
290 	sc->sc_region = malloc(sc->sc_regions * sizeof(struct cfi_region),
291 	    M_TEMP, M_WAITOK | M_ZERO);
292 	for (r = 0; r < sc->sc_regions; r++) {
293 		blocks = cfi_read_qry(sc, CFI_QRY_REGION(r)) |
294 		    (cfi_read_qry(sc, CFI_QRY_REGION(r) + 1) << 8);
295 		sc->sc_region[r].r_blocks = blocks + 1;
296 
297 		blksz = cfi_read_qry(sc, CFI_QRY_REGION(r) + 2) |
298 		    (cfi_read_qry(sc, CFI_QRY_REGION(r) + 3) << 8);
299 		sc->sc_region[r].r_blksz = (blksz == 0) ? 128 :
300 		    blksz * 256;
301 	}
302 
303 	/* Reset the device to a default state. */
304 	cfi_write(sc, 0, CFI_BCS_CLEAR_STATUS);
305 
306 	if (bootverbose) {
307 		device_printf(dev, "[");
308 		for (r = 0; r < sc->sc_regions; r++) {
309 			printf("%ux%s%s", sc->sc_region[r].r_blocks,
310 			    cfi_fmtsize(sc->sc_region[r].r_blksz),
311 			    (r == sc->sc_regions - 1) ? "]\n" : ",");
312 		}
313 	}
314 
315 	u = device_get_unit(dev);
316 	sc->sc_nod = make_dev(&cfi_cdevsw, u, UID_ROOT, GID_WHEEL, 0600,
317 	    "%s%u", cfi_driver_name, u);
318 	sc->sc_nod->si_drv1 = sc;
319 
320 #ifdef CFI_SUPPORT_STRATAFLASH
321 	/*
322 	 * Store the Intel factory PPR in the environment.  In some
323 	 * cases it is the most unique ID on a board.
324 	 */
325 	if (cfi_intel_get_factory_pr(sc, &ppr) == 0) {
326 		if (snprintf(name, sizeof(name), "%s.factory_ppr",
327 		    device_get_nameunit(dev)) < (sizeof(name) - 1) &&
328 		    snprintf(value, sizeof(value), "0x%016jx", ppr) <
329 		    (sizeof(value) - 1))
330 			(void) setenv(name, value);
331 	}
332 #endif
333 
334 	device_add_child(dev, "cfid", -1);
335 	bus_generic_attach(dev);
336 
337 	return (0);
338 }
339 
340 int
341 cfi_detach(device_t dev)
342 {
343 	struct cfi_softc *sc;
344 
345 	sc = device_get_softc(dev);
346 
347 	destroy_dev(sc->sc_nod);
348 	free(sc->sc_region, M_TEMP);
349 	bus_release_resource(dev, SYS_RES_MEMORY, sc->sc_rid, sc->sc_res);
350 	return (0);
351 }
352 
353 static int
354 cfi_wait_ready(struct cfi_softc *sc, u_int ofs, u_int timeout)
355 {
356 	int done, error;
357 	uint32_t st0 = 0, st = 0;
358 
359 	done = 0;
360 	error = 0;
361 	timeout *= 10;
362 	while (!done && !error && timeout) {
363 		DELAY(100);
364 		timeout--;
365 
366 		switch (sc->sc_cmdset) {
367 		case CFI_VEND_INTEL_ECS:
368 		case CFI_VEND_INTEL_SCS:
369 			st = cfi_read(sc, ofs);
370 			done = (st & CFI_INTEL_STATUS_WSMS);
371 			if (done) {
372 				/* NB: bit 0 is reserved */
373 				st &= ~(CFI_INTEL_XSTATUS_RSVD |
374 					CFI_INTEL_STATUS_WSMS |
375 					CFI_INTEL_STATUS_RSVD);
376 				if (st & CFI_INTEL_STATUS_DPS)
377 					error = EPERM;
378 				else if (st & CFI_INTEL_STATUS_PSLBS)
379 					error = EIO;
380 				else if (st & CFI_INTEL_STATUS_ECLBS)
381 					error = ENXIO;
382 				else if (st)
383 					error = EACCES;
384 			}
385 			break;
386 		case CFI_VEND_AMD_SCS:
387 		case CFI_VEND_AMD_ECS:
388 			st0 = cfi_read(sc, ofs);
389 			st = cfi_read(sc, ofs);
390 			done = ((st & 0x40) == (st0 & 0x40)) ? 1 : 0;
391 			break;
392 		}
393 	}
394 	if (!done && !error)
395 		error = ETIMEDOUT;
396 	if (error)
397 		printf("\nerror=%d (st 0x%x st0 0x%x)\n", error, st, st0);
398 	return (error);
399 }
400 
401 int
402 cfi_write_block(struct cfi_softc *sc)
403 {
404 	union {
405 		uint8_t		*x8;
406 		uint16_t	*x16;
407 		uint32_t	*x32;
408 	} ptr;
409 	register_t intr;
410 	int error, i;
411 
412 	/* Erase the block. */
413 	switch (sc->sc_cmdset) {
414 	case CFI_VEND_INTEL_ECS:
415 	case CFI_VEND_INTEL_SCS:
416 		cfi_write(sc, sc->sc_wrofs, CFI_BCS_BLOCK_ERASE);
417 		cfi_write(sc, sc->sc_wrofs, CFI_BCS_CONFIRM);
418 		break;
419 	case CFI_VEND_AMD_SCS:
420 	case CFI_VEND_AMD_ECS:
421 		cfi_amd_write(sc, sc->sc_wrofs, AMD_ADDR_START,
422 		    CFI_AMD_ERASE_SECTOR);
423 		cfi_amd_write(sc, sc->sc_wrofs, 0, CFI_AMD_BLOCK_ERASE);
424 		break;
425 	default:
426 		/* Better safe than sorry... */
427 		return (ENODEV);
428 	}
429 	error = cfi_wait_ready(sc, sc->sc_wrofs, sc->sc_erase_timeout);
430 	if (error)
431 		goto out;
432 
433 	/* Write the block. */
434 	ptr.x8 = sc->sc_wrbuf;
435 	for (i = 0; i < sc->sc_wrbufsz; i += sc->sc_width) {
436 
437 		/*
438 		 * Make sure the command to start a write and the
439 		 * actual write happens back-to-back without any
440 		 * excessive delays.
441 		 */
442 		intr = intr_disable();
443 
444 		switch (sc->sc_cmdset) {
445 		case CFI_VEND_INTEL_ECS:
446 		case CFI_VEND_INTEL_SCS:
447 			cfi_write(sc, sc->sc_wrofs + i, CFI_BCS_PROGRAM);
448 			break;
449 		case CFI_VEND_AMD_SCS:
450 		case CFI_VEND_AMD_ECS:
451 			cfi_amd_write(sc, 0, AMD_ADDR_START, CFI_AMD_PROGRAM);
452 			break;
453 		}
454 		switch (sc->sc_width) {
455 		case 1:
456 			bus_space_write_1(sc->sc_tag, sc->sc_handle,
457 			    sc->sc_wrofs + i, *(ptr.x8)++);
458 			break;
459 		case 2:
460 			bus_space_write_2(sc->sc_tag, sc->sc_handle,
461 			    sc->sc_wrofs + i, *(ptr.x16)++);
462 			break;
463 		case 4:
464 			bus_space_write_4(sc->sc_tag, sc->sc_handle,
465 			    sc->sc_wrofs + i, *(ptr.x32)++);
466 			break;
467 		}
468 
469 		intr_restore(intr);
470 
471 		error = cfi_wait_ready(sc, sc->sc_wrofs, sc->sc_write_timeout);
472 		if (error)
473 			goto out;
474 	}
475 
476 	/* error is 0. */
477 
478  out:
479 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
480 	return (error);
481 }
482 
483 #ifdef CFI_SUPPORT_STRATAFLASH
484 /*
485  * Intel StrataFlash Protection Register Support.
486  *
487  * The memory includes a 128-bit Protection Register that can be
488  * used for security.  There are two 64-bit segments; one is programmed
489  * at the factory with a unique 64-bit number which is immutable.
490  * The other segment is left blank for User (OEM) programming.
491  * The User/OEM segment is One Time Programmable (OTP).  It can also
492  * be locked to prevent any further writes by setting bit 0 of the
493  * Protection Lock Register (PLR).  The PLR can written only once.
494  */
495 
496 static uint16_t
497 cfi_get16(struct cfi_softc *sc, int off)
498 {
499 	uint16_t v = bus_space_read_2(sc->sc_tag, sc->sc_handle, off<<1);
500 	return v;
501 }
502 
503 #ifdef CFI_ARMEDANDDANGEROUS
504 static void
505 cfi_put16(struct cfi_softc *sc, int off, uint16_t v)
506 {
507 	bus_space_write_2(sc->sc_tag, sc->sc_handle, off<<1, v);
508 }
509 #endif
510 
511 /*
512  * Read the factory-defined 64-bit segment of the PR.
513  */
514 int
515 cfi_intel_get_factory_pr(struct cfi_softc *sc, uint64_t *id)
516 {
517 	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
518 		return EOPNOTSUPP;
519 	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));
520 
521 	cfi_write(sc, 0, CFI_INTEL_READ_ID);
522 	*id = ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(0)))<<48 |
523 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(1)))<<32 |
524 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(2)))<<16 |
525 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(3)));
526 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
527 	return 0;
528 }
529 
530 /*
531  * Read the User/OEM 64-bit segment of the PR.
532  */
533 int
534 cfi_intel_get_oem_pr(struct cfi_softc *sc, uint64_t *id)
535 {
536 	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
537 		return EOPNOTSUPP;
538 	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));
539 
540 	cfi_write(sc, 0, CFI_INTEL_READ_ID);
541 	*id = ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(4)))<<48 |
542 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(5)))<<32 |
543 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(6)))<<16 |
544 	      ((uint64_t)cfi_get16(sc, CFI_INTEL_PR(7)));
545 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
546 	return 0;
547 }
548 
549 /*
550  * Write the User/OEM 64-bit segment of the PR.
551  * XXX should allow writing individual words/bytes
552  */
553 int
554 cfi_intel_set_oem_pr(struct cfi_softc *sc, uint64_t id)
555 {
556 #ifdef CFI_ARMEDANDDANGEROUS
557 	register_t intr;
558 	int i, error;
559 #endif
560 
561 	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
562 		return EOPNOTSUPP;
563 	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));
564 
565 #ifdef CFI_ARMEDANDDANGEROUS
566 	for (i = 7; i >= 4; i--, id >>= 16) {
567 		intr = intr_disable();
568 		cfi_write(sc, 0, CFI_INTEL_PP_SETUP);
569 		cfi_put16(sc, CFI_INTEL_PR(i), id&0xffff);
570 		intr_restore(intr);
571 		error = cfi_wait_ready(sc, CFI_BCS_READ_STATUS,
572 		    sc->sc_write_timeout);
573 		if (error)
574 			break;
575 	}
576 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
577 	return error;
578 #else
579 	device_printf(sc->sc_dev, "%s: OEM PR not set, "
580 	    "CFI_ARMEDANDDANGEROUS not configured\n", __func__);
581 	return ENXIO;
582 #endif
583 }
584 
585 /*
586  * Read the contents of the Protection Lock Register.
587  */
588 int
589 cfi_intel_get_plr(struct cfi_softc *sc, uint32_t *plr)
590 {
591 	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
592 		return EOPNOTSUPP;
593 	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));
594 
595 	cfi_write(sc, 0, CFI_INTEL_READ_ID);
596 	*plr = cfi_get16(sc, CFI_INTEL_PLR);
597 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
598 	return 0;
599 }
600 
601 /*
602  * Write the Protection Lock Register to lock down the
603  * user-settable segment of the Protection Register.
604  * NOTE: this operation is not reversible.
605  */
606 int
607 cfi_intel_set_plr(struct cfi_softc *sc)
608 {
609 #ifdef CFI_ARMEDANDDANGEROUS
610 	register_t intr;
611 	int error;
612 #endif
613 	if (sc->sc_cmdset != CFI_VEND_INTEL_ECS)
614 		return EOPNOTSUPP;
615 	KASSERT(sc->sc_width == 2, ("sc_width %d", sc->sc_width));
616 
617 #ifdef CFI_ARMEDANDDANGEROUS
618 	/* worthy of console msg */
619 	device_printf(sc->sc_dev, "set PLR\n");
620 	intr = intr_disable();
621 	cfi_write(sc, 0, CFI_INTEL_PP_SETUP);
622 	cfi_put16(sc, CFI_INTEL_PLR, 0xFFFD);
623 	intr_restore(intr);
624 	error = cfi_wait_ready(sc, CFI_BCS_READ_STATUS, sc->sc_write_timeout);
625 	cfi_write(sc, 0, CFI_BCS_READ_ARRAY);
626 	return error;
627 #else
628 	device_printf(sc->sc_dev, "%s: PLR not set, "
629 	    "CFI_ARMEDANDDANGEROUS not configured\n", __func__);
630 	return ENXIO;
631 #endif
632 }
633 #endif /* CFI_SUPPORT_STRATAFLASH */
634