xref: /netbsd-src/sys/dev/spi/spiflash.c (revision 49811c99f07ecb34956ba7e5eb757770251c9348)
1 /* $NetBSD: spiflash.c,v 1.27 2022/10/26 21:56:19 andvar Exp $ */
2 
3 /*-
4  * Copyright (c) 2006 Urbana-Champaign Independent Media Center.
5  * Copyright (c) 2006 Garrett D'Amore.
6  * All rights reserved.
7  *
8  * Portions of this code were written by Garrett D'Amore for the
9  * Champaign-Urbana Community Wireless Network Project.
10  *
11  * Redistribution and use in source and binary forms, with or
12  * without modification, are permitted provided that the following
13  * conditions are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above
17  *    copyright notice, this list of conditions and the following
18  *    disclaimer in the documentation and/or other materials provided
19  *    with the distribution.
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgements:
22  *      This product includes software developed by the Urbana-Champaign
23  *      Independent Media Center.
24  *	This product includes software developed by Garrett D'Amore.
25  * 4. Urbana-Champaign Independent Media Center's name and Garrett
26  *    D'Amore's name may not be used to endorse or promote products
27  *    derived from this software without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE URBANA-CHAMPAIGN INDEPENDENT
30  * MEDIA CENTER AND GARRETT D'AMORE ``AS IS'' AND ANY EXPRESS OR
31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
32  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE URBANA-CHAMPAIGN INDEPENDENT
34  * MEDIA CENTER OR GARRETT D'AMORE BE LIABLE FOR ANY DIRECT, INDIRECT,
35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42  */
43 
44 #include <sys/cdefs.h>
45 __KERNEL_RCSID(0, "$NetBSD: spiflash.c,v 1.27 2022/10/26 21:56:19 andvar Exp $");
46 
47 #include <sys/param.h>
48 #include <sys/conf.h>
49 #include <sys/proc.h>
50 #include <sys/systm.h>
51 #include <sys/device.h>
52 #include <sys/kernel.h>
53 #include <sys/file.h>
54 #include <sys/ioctl.h>
55 #include <sys/disk.h>
56 #include <sys/disklabel.h>
57 #include <sys/buf.h>
58 #include <sys/bufq.h>
59 #include <sys/uio.h>
60 #include <sys/kthread.h>
61 #include <sys/malloc.h>
62 #include <sys/errno.h>
63 
64 #include <dev/spi/spivar.h>
65 #include <dev/spi/spiflash.h>
66 
67 /*
68  * This is an MI block driver for SPI flash devices.  It could probably be
69  * converted to some more generic framework, if someone wanted to create one
70  * for NOR flashes.  Note that some flashes have the ability to handle
71  * interrupts.
72  */
73 
74 struct spiflash_softc {
75 	struct disk		sc_dk;
76 
77 	struct spiflash_hw_if	sc_hw;
78 	void			*sc_cookie;
79 
80 	const char		*sc_name;
81 	struct spi_handle	*sc_handle;
82 	int			sc_device_size;
83 	int			sc_write_size;
84 	int			sc_erase_size;
85 	int			sc_read_size;
86 	int			sc_device_blks;
87 
88 	struct bufq_state	*sc_waitq;
89 	struct bufq_state	*sc_workq;
90 	struct bufq_state	*sc_doneq;
91 	lwp_t			*sc_thread;
92 };
93 
94 #define	sc_getname	sc_hw.sf_getname
95 #define	sc_gethandle	sc_hw.sf_gethandle
96 #define	sc_getsize	sc_hw.sf_getsize
97 #define	sc_getflags	sc_hw.sf_getflags
98 #define	sc_erase	sc_hw.sf_erase
99 #define	sc_write	sc_hw.sf_write
100 #define	sc_read		sc_hw.sf_read
101 #define	sc_getstatus	sc_hw.sf_getstatus
102 #define	sc_setstatus	sc_hw.sf_setstatus
103 
104 struct spiflash_attach_args {
105 	const struct spiflash_hw_if	*hw;
106 	void				*cookie;
107 };
108 
109 #define	STATIC
110 STATIC int spiflash_match(device_t , cfdata_t , void *);
111 STATIC void spiflash_attach(device_t , device_t , void *);
112 STATIC int spiflash_print(void *, const char *);
113 STATIC int spiflash_common_erase(spiflash_handle_t, size_t, size_t);
114 STATIC int spiflash_common_write(spiflash_handle_t, size_t, size_t,
115     const uint8_t *);
116 STATIC int spiflash_common_read(spiflash_handle_t, size_t, size_t, uint8_t *);
117 STATIC void spiflash_process_done(spiflash_handle_t, int);
118 STATIC void spiflash_process_read(spiflash_handle_t);
119 STATIC void spiflash_process_write(spiflash_handle_t);
120 STATIC void spiflash_thread(void *);
121 STATIC int spiflash_nsectors(spiflash_handle_t, struct buf *);
122 STATIC int spiflash_nsectors(spiflash_handle_t, struct buf *);
123 STATIC int spiflash_sector(spiflash_handle_t, struct buf *);
124 
125 CFATTACH_DECL_NEW(spiflash, sizeof(struct spiflash_softc),
126 	      spiflash_match, spiflash_attach, NULL, NULL);
127 
128 #ifdef	SPIFLASH_DEBUG
129 #define	DPRINTF(x)	do { printf x; } while (0/*CONSTCOND*/)
130 #else
131 #define	DPRINTF(x)	do {  } while (0/*CONSTCOND*/)
132 #endif
133 
134 extern struct cfdriver spiflash_cd;
135 
136 dev_type_open(spiflash_open);
137 dev_type_close(spiflash_close);
138 dev_type_read(spiflash_read);
139 dev_type_write(spiflash_write);
140 dev_type_ioctl(spiflash_ioctl);
141 dev_type_strategy(spiflash_strategy);
142 
143 const struct bdevsw spiflash_bdevsw = {
144 	.d_open = spiflash_open,
145 	.d_close = spiflash_close,
146 	.d_strategy = spiflash_strategy,
147 	.d_ioctl = spiflash_ioctl,
148 	.d_dump = nodump,
149 	.d_psize = nosize,
150 	.d_discard = nodiscard,
151 	.d_flag = D_DISK,
152 };
153 
154 const struct cdevsw spiflash_cdevsw = {
155 	.d_open = spiflash_open,
156 	.d_close = spiflash_close,
157 	.d_read = spiflash_read,
158 	.d_write = spiflash_write,
159 	.d_ioctl = spiflash_ioctl,
160 	.d_stop = nostop,
161 	.d_tty = notty,
162 	.d_poll = nopoll,
163 	.d_mmap = nommap,
164 	.d_kqfilter = nokqfilter,
165 	.d_discard = nodiscard,
166 	.d_flag = D_DISK,
167 };
168 
169 static struct dkdriver spiflash_dkdriver = {
170 	.d_strategy = spiflash_strategy
171 };
172 
173 spiflash_handle_t
spiflash_attach_mi(const struct spiflash_hw_if * hw,void * cookie,device_t dev)174 spiflash_attach_mi(const struct spiflash_hw_if *hw, void *cookie,
175     device_t dev)
176 {
177 	struct spiflash_attach_args sfa;
178 	sfa.hw = hw;
179 	sfa.cookie = cookie;
180 
181 	return (spiflash_handle_t)config_found(dev, &sfa, spiflash_print,
182 	    CFARGS_NONE);
183 }
184 
185 int
spiflash_print(void * aux,const char * pnp)186 spiflash_print(void *aux, const char *pnp)
187 {
188 	if (pnp != NULL)
189 		printf("spiflash at %s\n", pnp);
190 
191 	return UNCONF;
192 }
193 
194 int
spiflash_match(device_t parent,cfdata_t cf,void * aux)195 spiflash_match(device_t parent, cfdata_t cf, void *aux)
196 {
197 
198 	return 1;
199 }
200 
201 void
spiflash_attach(device_t parent,device_t self,void * aux)202 spiflash_attach(device_t parent, device_t self, void *aux)
203 {
204 	struct spiflash_softc *sc = device_private(self);
205 	struct spiflash_attach_args *sfa = aux;
206 	void *cookie = sfa->cookie;
207 
208 	sc->sc_hw = *sfa->hw;
209 	sc->sc_cookie = cookie;
210 	sc->sc_name = sc->sc_getname(cookie);
211 	sc->sc_handle = sc->sc_gethandle(cookie);
212 	sc->sc_device_size = sc->sc_getsize(cookie, SPIFLASH_SIZE_DEVICE);
213 	sc->sc_erase_size = sc->sc_getsize(cookie, SPIFLASH_SIZE_ERASE);
214 	sc->sc_write_size = sc->sc_getsize(cookie, SPIFLASH_SIZE_WRITE);
215 	sc->sc_read_size = sc->sc_getsize(cookie, SPIFLASH_SIZE_READ);
216 	sc->sc_device_blks = sc->sc_device_size / DEV_BSIZE;
217 
218 	if (sc->sc_read == NULL)
219 		sc->sc_read = spiflash_common_read;
220 	if (sc->sc_write == NULL)
221 		sc->sc_write = spiflash_common_write;
222 	if (sc->sc_erase == NULL)
223 		sc->sc_erase = spiflash_common_erase;
224 
225 	aprint_naive(": SPI flash\n");
226 	aprint_normal(": %s SPI flash\n", sc->sc_name);
227 	/* XXX: note that this has to change for boot-sectored flash */
228 	aprint_normal_dev(self, "%d KB, %d sectors of %d KB each\n",
229 	    sc->sc_device_size / 1024,
230 	    sc->sc_device_size / sc->sc_erase_size,
231 	    sc->sc_erase_size / 1024);
232 
233 	/* first-come first-served strategy works best for us */
234 	bufq_alloc(&sc->sc_waitq, "fcfs", BUFQ_SORT_RAWBLOCK);
235 	bufq_alloc(&sc->sc_workq, "fcfs", BUFQ_SORT_RAWBLOCK);
236 	bufq_alloc(&sc->sc_doneq, "fcfs", BUFQ_SORT_RAWBLOCK);
237 
238 	disk_init(&sc->sc_dk, device_xname(self), &spiflash_dkdriver);
239 	disk_attach(&sc->sc_dk);
240 
241 	/* arrange to allocate the kthread */
242 	kthread_create(PRI_NONE, 0, NULL, spiflash_thread, sc,
243 	    &sc->sc_thread, "spiflash");
244 }
245 
246 int
spiflash_open(dev_t dev,int flags,int mode,struct lwp * l)247 spiflash_open(dev_t dev, int flags, int mode, struct lwp *l)
248 {
249 	spiflash_handle_t sc;
250 
251 	sc = device_lookup_private(&spiflash_cd, DISKUNIT(dev));
252 	if (sc == NULL)
253 		return ENXIO;
254 
255 	/*
256 	 * XXX: We need to handle partitions here.  The problem is
257 	 * that it isn't entirely clear to me how to deal with this.
258 	 * There are devices that could be used "in the raw" with a
259 	 * NetBSD label, but then you get into devices that have other
260 	 * kinds of data on them -- some have VxWorks data, some have
261 	 * RedBoot data, and some have other constraints -- for example
262 	 * some devices might have a portion that is read-only,
263 	 * whereas others might have a portion that is read-write.
264 	 *
265 	 * For now we just permit access to the entire device.
266 	 */
267 	return 0;
268 }
269 
270 int
spiflash_close(dev_t dev,int flags,int mode,struct lwp * l)271 spiflash_close(dev_t dev, int flags, int mode, struct lwp *l)
272 {
273 	spiflash_handle_t sc;
274 
275 	sc = device_lookup_private(&spiflash_cd, DISKUNIT(dev));
276 	if (sc == NULL)
277 		return ENXIO;
278 
279 	return 0;
280 }
281 
282 int
spiflash_read(dev_t dev,struct uio * uio,int ioflag)283 spiflash_read(dev_t dev, struct uio *uio, int ioflag)
284 {
285 
286 	return physio(spiflash_strategy, NULL, dev, B_READ, minphys, uio);
287 }
288 
289 int
spiflash_write(dev_t dev,struct uio * uio,int ioflag)290 spiflash_write(dev_t dev, struct uio *uio, int ioflag)
291 {
292 
293 	return physio(spiflash_strategy, NULL, dev, B_WRITE, minphys, uio);
294 }
295 
296 int
spiflash_ioctl(dev_t dev,u_long cmd,void * data,int flags,struct lwp * l)297 spiflash_ioctl(dev_t dev, u_long cmd, void *data, int flags, struct lwp *l)
298 {
299 	spiflash_handle_t sc;
300 
301 	sc = device_lookup_private(&spiflash_cd, DISKUNIT(dev));
302 	if (sc == NULL)
303 		return ENXIO;
304 
305 	return EINVAL;
306 }
307 
308 void
spiflash_strategy(struct buf * bp)309 spiflash_strategy(struct buf *bp)
310 {
311 	spiflash_handle_t sc;
312 	int	s;
313 
314 	bp->b_resid = bp->b_bcount;
315 
316 	sc = device_lookup_private(&spiflash_cd, DISKUNIT(bp->b_dev));
317 	if (sc == NULL) {
318 		bp->b_error = ENXIO;
319 		biodone(bp);
320 		return;
321 	}
322 
323 	if (((bp->b_bcount % sc->sc_write_size) != 0) ||
324 	    (bp->b_blkno < 0)) {
325 		bp->b_error = EINVAL;
326 		biodone(bp);
327 		return;
328 	}
329 
330 	/* no work? */
331 	if (bp->b_bcount == 0) {
332 		biodone(bp);
333 		return;
334 	}
335 
336 	if (bounds_check_with_mediasize(bp, DEV_BSIZE,
337 		sc->sc_device_blks) <= 0) {
338 		biodone(bp);
339 		return;
340 	}
341 
342 	/* all ready, hand off to thread for async processing */
343 	s = splbio();
344 	bufq_put(sc->sc_waitq, bp);
345 	wakeup(&sc->sc_thread);
346 	splx(s);
347 }
348 
349 void
spiflash_process_done(spiflash_handle_t sc,int err)350 spiflash_process_done(spiflash_handle_t sc, int err)
351 {
352 	struct buf	*bp;
353 	int		cnt = 0;
354 	int		flag = 0;
355 
356 	while ((bp = bufq_get(sc->sc_doneq)) != NULL) {
357 		flag = bp->b_flags & B_READ;
358 		if ((bp->b_error = err) == 0)
359 			bp->b_resid = 0;
360 		cnt += bp->b_bcount - bp->b_resid;
361 		biodone(bp);
362 	}
363 	disk_unbusy(&sc->sc_dk, cnt, flag);
364 }
365 
366 void
spiflash_process_read(spiflash_handle_t sc)367 spiflash_process_read(spiflash_handle_t sc)
368 {
369 	struct buf	*bp;
370 	int		err = 0;
371 
372 	disk_busy(&sc->sc_dk);
373 	while ((bp = bufq_get(sc->sc_workq)) != NULL) {
374 		size_t addr = bp->b_blkno * DEV_BSIZE;
375 		uint8_t *data = bp->b_data;
376 		int cnt = bp->b_resid;
377 
378 		bufq_put(sc->sc_doneq, bp);
379 
380 		DPRINTF(("read from addr %x, cnt %d\n", (unsigned)addr, cnt));
381 
382 		if ((err = sc->sc_read(sc, addr, cnt, data)) != 0) {
383 			/* error occurred, fail all pending workq bufs */
384 			bufq_move(sc->sc_doneq, sc->sc_workq);
385 			break;
386 		}
387 
388 		bp->b_resid -= cnt;
389 		data += cnt;
390 		addr += cnt;
391 	}
392 	spiflash_process_done(sc, err);
393 }
394 
395 void
spiflash_process_write(spiflash_handle_t sc)396 spiflash_process_write(spiflash_handle_t sc)
397 {
398 	int	len;
399 	size_t	base;
400 	daddr_t	blkno;
401 	uint8_t	*save;
402 	int	err = 0, neederase = 0;
403 	struct buf *bp;
404 
405 	/*
406 	 * due to other considerations, we are guaranteed that
407 	 * we will only have multiple buffers if they are all in
408 	 * the same erase sector.  Therefore we never need to look
409 	 * beyond the first block to determine how much data we need
410 	 * to save.
411 	 */
412 
413 	bp = bufq_peek(sc->sc_workq);
414 	len = spiflash_nsectors(sc, bp)  * sc->sc_erase_size;
415 	blkno = bp->b_blkno;
416 	base = (blkno * DEV_BSIZE) & ~ (sc->sc_erase_size - 1);
417 
418 	/* get ourself a scratch buffer */
419 	save = malloc(len, M_DEVBUF, M_WAITOK);
420 
421 	disk_busy(&sc->sc_dk);
422 	/* read in as much of the data as we need */
423 	DPRINTF(("reading in %d bytes\n", len));
424 	if ((err = sc->sc_read(sc, base, len, save)) != 0) {
425 		bufq_move(sc->sc_doneq, sc->sc_workq);
426 		spiflash_process_done(sc, err);
427 		return;
428 	}
429 
430 	/*
431 	 * now coalesce the writes into the save area, but also
432 	 * check to see if we need to do an erase
433 	 */
434 	while ((bp = bufq_get(sc->sc_workq)) != NULL) {
435 		uint8_t	*data, *dst;
436 		int resid = bp->b_resid;
437 
438 		DPRINTF(("coalesce write, blkno %x, count %d, resid %d\n",
439 			    (unsigned)bp->b_blkno, bp->b_bcount, resid));
440 
441 		data = bp->b_data;
442 		dst = save + (bp->b_blkno * DEV_BSIZE) - base;
443 
444 		/*
445 		 * NOR flash bits.  We can clear a bit, but we cannot
446 		 * set a bit, without erasing.  This should help reduce
447 		 * unnecessary erases.
448 		 */
449 		while (resid) {
450 			if ((*data) & ~(*dst))
451 				neederase = 1;
452 			*dst++ = *data++;
453 			resid--;
454 		}
455 
456 		bufq_put(sc->sc_doneq, bp);
457 	}
458 
459 	/*
460 	 * do the erase, if we need to.
461 	 */
462 	if (neederase) {
463 		DPRINTF(("erasing from %zx - %zx\n", base, base + len));
464 		if ((err = sc->sc_erase(sc, base, len)) != 0) {
465 			spiflash_process_done(sc, err);
466 			return;
467 		}
468 	}
469 
470 	/*
471 	 * now write our save area, and finish up.
472 	 */
473 	DPRINTF(("flashing %d bytes to %zx from %p\n", len, base, save));
474 	err = sc->sc_write(sc, base, len, save);
475 	spiflash_process_done(sc, err);
476 }
477 
478 
479 int
spiflash_nsectors(spiflash_handle_t sc,struct buf * bp)480 spiflash_nsectors(spiflash_handle_t sc, struct buf *bp)
481 {
482 	unsigned	addr, sector;
483 
484 	addr = bp->b_blkno * DEV_BSIZE;
485 	sector = addr / sc->sc_erase_size;
486 
487 	addr += bp->b_bcount;
488 	addr--;
489 	return (((addr / sc->sc_erase_size)  - sector) + 1);
490 }
491 
492 int
spiflash_sector(spiflash_handle_t sc,struct buf * bp)493 spiflash_sector(spiflash_handle_t sc, struct buf *bp)
494 {
495 	unsigned	addr, sector;
496 
497 	addr = bp->b_blkno * DEV_BSIZE;
498 	sector = addr / sc->sc_erase_size;
499 
500 	/* if it spans multiple blocks, error it */
501 	addr += bp->b_bcount;
502 	addr--;
503 	if (sector != (addr / sc->sc_erase_size))
504 		return -1;
505 
506 	return sector;
507 }
508 
509 void
spiflash_thread(void * arg)510 spiflash_thread(void *arg)
511 {
512 	spiflash_handle_t sc = arg;
513 	struct buf	*bp;
514 	int		sector;
515 
516 	(void)splbio();
517 	for (;;) {
518 		if ((bp = bufq_get(sc->sc_waitq)) == NULL) {
519 			tsleep(&sc->sc_thread, PRIBIO, "spiflash_thread", 0);
520 			continue;
521 		}
522 
523 		bufq_put(sc->sc_workq, bp);
524 
525 		if (bp->b_flags & B_READ) {
526 			/* just do the read */
527 			spiflash_process_read(sc);
528 			continue;
529 		}
530 
531 		/*
532 		 * Because writing a flash filesystem is particularly
533 		 * painful, involving erase, modify, write, we prefer
534 		 * to coalesce writes to the same sector together.
535 		 */
536 
537 		sector = spiflash_sector(sc, bp);
538 
539 		/*
540 		 * if the write spans multiple sectors, skip
541 		 * coalescing.  (It would be nice if we could break
542 		 * these up.  minphys is honored for read/write, but
543 		 * not necessarily for bread.)
544 		 */
545 		if (sector < 0)
546 			goto dowrite;
547 
548 		while ((bp = bufq_peek(sc->sc_waitq)) != NULL) {
549 			/* can't deal with read requests! */
550 			if (bp->b_flags & B_READ)
551 				break;
552 
553 			/* is it for the same sector? */
554 			if (spiflash_sector(sc, bp) != sector)
555 				break;
556 
557 			bp = bufq_get(sc->sc_waitq);
558 			bufq_put(sc->sc_workq, bp);
559 		}
560 
561 	dowrite:
562 		spiflash_process_write(sc);
563 	}
564 }
565 /*
566  * SPI flash common implementation.
567  */
568 
569 /*
570  * Most devices take on the order of 1 second for each block that they
571  * delete.
572  */
573 int
spiflash_common_erase(spiflash_handle_t sc,size_t start,size_t size)574 spiflash_common_erase(spiflash_handle_t sc, size_t start, size_t size)
575 {
576 	int		rv;
577 
578 	if ((start % sc->sc_erase_size) || (size % sc->sc_erase_size))
579 		return EINVAL;
580 
581 	/* the second test is to test against wrap */
582 	if ((start > sc->sc_device_size) ||
583 	    ((start + size) > sc->sc_device_size))
584 		return EINVAL;
585 
586 	/*
587 	 * XXX: check protection status?  Requires master table mapping
588 	 * sectors to status bits, and so forth.
589 	 */
590 
591 	while (size) {
592 		if ((rv = spiflash_write_enable(sc)) != 0) {
593 			spiflash_write_disable(sc);
594 			return rv;
595 		}
596 		if ((rv = spiflash_cmd(sc, SPIFLASH_CMD_ERASE, 3, start, 0,
597 			 NULL, NULL)) != 0) {
598 			spiflash_write_disable(sc);
599 			return rv;
600 		}
601 
602 		/*
603 		 * The devices I have all say typical for sector erase
604 		 * is ~1sec.  We check ten times that often.  (There
605 		 * is no way to interrupt on this.)
606 		 */
607 		if ((rv = spiflash_wait(sc, hz / 10)) != 0)
608 			return rv;
609 
610 		start += sc->sc_erase_size;
611 		size -= sc->sc_erase_size;
612 
613 		/* NB: according to the docs I have, the write enable
614 		 * is automatically cleared upon completion of an erase
615 		 * command, so there is no need to explicitly disable it.
616 		 */
617 	}
618 
619 	return 0;
620 }
621 
622 int
spiflash_common_write(spiflash_handle_t sc,size_t start,size_t size,const uint8_t * data)623 spiflash_common_write(spiflash_handle_t sc, size_t start, size_t size,
624     const uint8_t *data)
625 {
626 	int		rv;
627 
628 	if ((start % sc->sc_write_size) || (size % sc->sc_write_size))
629 		return EINVAL;
630 
631 	while (size) {
632 		int cnt;
633 
634 		if ((rv = spiflash_write_enable(sc)) != 0) {
635 			spiflash_write_disable(sc);
636 			return rv;
637 		}
638 
639 		cnt = uimin(size, sc->sc_write_size);
640 		if ((rv = spiflash_cmd(sc, SPIFLASH_CMD_PROGRAM, 3, start,
641 			 cnt, data, NULL)) != 0) {
642 			spiflash_write_disable(sc);
643 			return rv;
644 		}
645 
646 		/*
647 		 * It seems that most devices can write bits fairly
648 		 * quickly.  For example, one part I have access to
649 		 * takes ~5msec to process the entire 256 byte page.
650 		 * Probably this should be modified to cope with
651 		 * device-specific timing, and maybe also take into
652 		 * account systems with higher values of HZ (which
653 		 * could benefit from sleeping.)
654 		 */
655 		if ((rv = spiflash_wait(sc, 0)) != 0)
656 			return rv;
657 
658 		data += cnt;
659 		start += cnt;
660 		size -= cnt;
661 	}
662 
663 	return 0;
664 }
665 
666 int
spiflash_common_read(spiflash_handle_t sc,size_t start,size_t size,uint8_t * data)667 spiflash_common_read(spiflash_handle_t sc, size_t start, size_t size,
668     uint8_t *data)
669 {
670 	int		rv;
671 
672 	while (size) {
673 		int cnt;
674 
675 		if (sc->sc_read_size > 0)
676 			cnt = uimin(size, sc->sc_read_size);
677 		else
678 			cnt = size;
679 
680 		if ((rv = spiflash_cmd(sc, SPIFLASH_CMD_READ, 3, start,
681 			 cnt, NULL, data)) != 0) {
682 			return rv;
683 		}
684 
685 		data += cnt;
686 		start += cnt;
687 		size -= cnt;
688 	}
689 
690 	return 0;
691 }
692 
693 /* read status register */
694 int
spiflash_read_status(spiflash_handle_t sc,uint8_t * sr)695 spiflash_read_status(spiflash_handle_t sc, uint8_t *sr)
696 {
697 
698 	return spiflash_cmd(sc, SPIFLASH_CMD_RDSR, 0, 0, 1, NULL, sr);
699 }
700 
701 int
spiflash_write_enable(spiflash_handle_t sc)702 spiflash_write_enable(spiflash_handle_t sc)
703 {
704 
705 	return spiflash_cmd(sc, SPIFLASH_CMD_WREN, 0, 0, 0, NULL, NULL);
706 }
707 
708 int
spiflash_write_disable(spiflash_handle_t sc)709 spiflash_write_disable(spiflash_handle_t sc)
710 {
711 
712 	return spiflash_cmd(sc, SPIFLASH_CMD_WRDI, 0, 0, 0, NULL, NULL);
713 }
714 
715 int
spiflash_cmd(spiflash_handle_t sc,uint8_t cmd,size_t addrlen,uint32_t addr,size_t cnt,const uint8_t * wdata,uint8_t * rdata)716 spiflash_cmd(spiflash_handle_t sc, uint8_t cmd,
717     size_t addrlen, uint32_t addr,
718     size_t cnt, const uint8_t *wdata, uint8_t *rdata)
719 {
720 	struct spi_transfer	trans;
721 	struct spi_chunk	chunk1, chunk2;
722 	char buf[4];
723 	int i;
724 
725 	buf[0] = cmd;
726 
727 	if (addrlen > 3)
728 		return EINVAL;
729 
730 	for (i = addrlen; i > 0; i--) {
731 		buf[i] = addr & 0xff;
732 		addr >>= 8;
733 	}
734 	spi_transfer_init(&trans);
735 	spi_chunk_init(&chunk1, addrlen + 1, buf, NULL);
736 	spi_transfer_add(&trans, &chunk1);
737 	if (cnt) {
738 		spi_chunk_init(&chunk2, cnt, wdata, rdata);
739 		spi_transfer_add(&trans, &chunk2);
740 	}
741 
742 	spi_transfer(sc->sc_handle, &trans);
743 	spi_wait(&trans);
744 
745 	if (trans.st_flags & SPI_F_ERROR)
746 		return trans.st_errno;
747 	return 0;
748 }
749 
750 int
spiflash_wait(spiflash_handle_t sc,int tmo)751 spiflash_wait(spiflash_handle_t sc, int tmo)
752 {
753 	int	rv;
754 	uint8_t	sr;
755 
756 	for (;;) {
757 		if ((rv = spiflash_read_status(sc, &sr)) != 0)
758 			return rv;
759 
760 		if ((sr & SPIFLASH_SR_BUSY) == 0)
761 			break;
762 		/*
763 		 * The devices I have all say typical for sector
764 		 * erase is ~1sec.  We check time times that often.
765 		 * (There is no way to interrupt on this.)
766 		 */
767 		if (tmo)
768 			tsleep(&sr, PWAIT, "spiflash_wait", tmo);
769 	}
770 	return 0;
771 }
772