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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/mtd/devices/
1/*
2 * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
3 *
4 * Largely derived from at91_dataflash.c:
5 *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11*/
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/slab.h>
15#include <linux/delay.h>
16#include <linux/device.h>
17#include <linux/mutex.h>
18#include <linux/err.h>
19#include <linux/math64.h>
20
21#include <linux/spi/spi.h>
22#include <linux/spi/flash.h>
23
24#include <linux/mtd/mtd.h>
25#include <linux/mtd/partitions.h>
26
27
28/*
29 * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
30 * each chip, which may be used for double buffered I/O; but this driver
31 * doesn't (yet) use these for any kind of i/o overlap or prefetching.
32 *
33 * Sometimes DataFlash is packaged in MMC-format cards, although the
34 * MMC stack can't (yet?) distinguish between MMC and DataFlash
35 * protocols during enumeration.
36 */
37
38/* reads can bypass the buffers */
39#define OP_READ_CONTINUOUS	0xE8
40#define OP_READ_PAGE		0xD2
41
42/* group B requests can run even while status reports "busy" */
43#define OP_READ_STATUS		0xD7	/* group B */
44
45/* move data between host and buffer */
46#define OP_READ_BUFFER1		0xD4	/* group B */
47#define OP_READ_BUFFER2		0xD6	/* group B */
48#define OP_WRITE_BUFFER1	0x84	/* group B */
49#define OP_WRITE_BUFFER2	0x87	/* group B */
50
51/* erasing flash */
52#define OP_ERASE_PAGE		0x81
53#define OP_ERASE_BLOCK		0x50
54
55/* move data between buffer and flash */
56#define OP_TRANSFER_BUF1	0x53
57#define OP_TRANSFER_BUF2	0x55
58#define OP_MREAD_BUFFER1	0xD4
59#define OP_MREAD_BUFFER2	0xD6
60#define OP_MWERASE_BUFFER1	0x83
61#define OP_MWERASE_BUFFER2	0x86
62#define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
63#define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */
64
65/* write to buffer, then write-erase to flash */
66#define OP_PROGRAM_VIA_BUF1	0x82
67#define OP_PROGRAM_VIA_BUF2	0x85
68
69/* compare buffer to flash */
70#define OP_COMPARE_BUF1		0x60
71#define OP_COMPARE_BUF2		0x61
72
73/* read flash to buffer, then write-erase to flash */
74#define OP_REWRITE_VIA_BUF1	0x58
75#define OP_REWRITE_VIA_BUF2	0x59
76
77/* newer chips report JEDEC manufacturer and device IDs; chip
78 * serial number and OTP bits; and per-sector writeprotect.
79 */
80#define OP_READ_ID		0x9F
81#define OP_READ_SECURITY	0x77
82#define OP_WRITE_SECURITY_REVC	0x9A
83#define OP_WRITE_SECURITY	0x9B	/* revision D */
84
85
86struct dataflash {
87	uint8_t			command[4];
88	char			name[24];
89
90	unsigned		partitioned:1;
91
92	unsigned short		page_offset;	/* offset in flash address */
93	unsigned int		page_size;	/* of bytes per page */
94
95	struct mutex		lock;
96	struct spi_device	*spi;
97
98	struct mtd_info		mtd;
99};
100
101/* ......................................................................... */
102
103/*
104 * Return the status of the DataFlash device.
105 */
106static inline int dataflash_status(struct spi_device *spi)
107{
108	/* NOTE:  at45db321c over 25 MHz wants to write
109	 * a dummy byte after the opcode...
110	 */
111	return spi_w8r8(spi, OP_READ_STATUS);
112}
113
114/*
115 * Poll the DataFlash device until it is READY.
116 * This usually takes 5-20 msec or so; more for sector erase.
117 */
118static int dataflash_waitready(struct spi_device *spi)
119{
120	int	status;
121
122	for (;;) {
123		status = dataflash_status(spi);
124		if (status < 0) {
125			DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n",
126					dev_name(&spi->dev), status);
127			status = 0;
128		}
129
130		if (status & (1 << 7))	/* RDY/nBSY */
131			return status;
132
133		msleep(3);
134	}
135}
136
137/* ......................................................................... */
138
139/*
140 * Erase pages of flash.
141 */
142static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
143{
144	struct dataflash	*priv = mtd->priv;
145	struct spi_device	*spi = priv->spi;
146	struct spi_transfer	x = { .tx_dma = 0, };
147	struct spi_message	msg;
148	unsigned		blocksize = priv->page_size << 3;
149	uint8_t			*command;
150	uint32_t		rem;
151
152	DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%llx len 0x%llx\n",
153	      dev_name(&spi->dev), (long long)instr->addr,
154	      (long long)instr->len);
155
156	/* Sanity checks */
157	if (instr->addr + instr->len > mtd->size)
158		return -EINVAL;
159	div_u64_rem(instr->len, priv->page_size, &rem);
160	if (rem)
161		return -EINVAL;
162	div_u64_rem(instr->addr, priv->page_size, &rem);
163	if (rem)
164		return -EINVAL;
165
166	spi_message_init(&msg);
167
168	x.tx_buf = command = priv->command;
169	x.len = 4;
170	spi_message_add_tail(&x, &msg);
171
172	mutex_lock(&priv->lock);
173	while (instr->len > 0) {
174		unsigned int	pageaddr;
175		int		status;
176		int		do_block;
177
178		/* Calculate flash page address; use block erase (for speed) if
179		 * we're at a block boundary and need to erase the whole block.
180		 */
181		pageaddr = div_u64(instr->addr, priv->page_size);
182		do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
183		pageaddr = pageaddr << priv->page_offset;
184
185		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
186		command[1] = (uint8_t)(pageaddr >> 16);
187		command[2] = (uint8_t)(pageaddr >> 8);
188		command[3] = 0;
189
190		DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n",
191			do_block ? "block" : "page",
192			command[0], command[1], command[2], command[3],
193			pageaddr);
194
195		status = spi_sync(spi, &msg);
196		(void) dataflash_waitready(spi);
197
198		if (status < 0) {
199			printk(KERN_ERR "%s: erase %x, err %d\n",
200				dev_name(&spi->dev), pageaddr, status);
201			/* REVISIT:  can retry instr->retries times; or
202			 * giveup and instr->fail_addr = instr->addr;
203			 */
204			continue;
205		}
206
207		if (do_block) {
208			instr->addr += blocksize;
209			instr->len -= blocksize;
210		} else {
211			instr->addr += priv->page_size;
212			instr->len -= priv->page_size;
213		}
214	}
215	mutex_unlock(&priv->lock);
216
217	/* Inform MTD subsystem that erase is complete */
218	instr->state = MTD_ERASE_DONE;
219	mtd_erase_callback(instr);
220
221	return 0;
222}
223
224/*
225 * Read from the DataFlash device.
226 *   from   : Start offset in flash device
227 *   len    : Amount to read
228 *   retlen : About of data actually read
229 *   buf    : Buffer containing the data
230 */
231static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
232			       size_t *retlen, u_char *buf)
233{
234	struct dataflash	*priv = mtd->priv;
235	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
236	struct spi_message	msg;
237	unsigned int		addr;
238	uint8_t			*command;
239	int			status;
240
241	DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n",
242		dev_name(&priv->spi->dev), (unsigned)from, (unsigned)(from + len));
243
244	*retlen = 0;
245
246	/* Sanity checks */
247	if (!len)
248		return 0;
249	if (from + len > mtd->size)
250		return -EINVAL;
251
252	/* Calculate flash page/byte address */
253	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
254		+ ((unsigned)from % priv->page_size);
255
256	command = priv->command;
257
258	DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n",
259		command[0], command[1], command[2], command[3]);
260
261	spi_message_init(&msg);
262
263	x[0].tx_buf = command;
264	x[0].len = 8;
265	spi_message_add_tail(&x[0], &msg);
266
267	x[1].rx_buf = buf;
268	x[1].len = len;
269	spi_message_add_tail(&x[1], &msg);
270
271	mutex_lock(&priv->lock);
272
273	/* Continuous read, max clock = f(car) which may be less than
274	 * the peak rate available.  Some chips support commands with
275	 * fewer "don't care" bytes.  Both buffers stay unchanged.
276	 */
277	command[0] = OP_READ_CONTINUOUS;
278	command[1] = (uint8_t)(addr >> 16);
279	command[2] = (uint8_t)(addr >> 8);
280	command[3] = (uint8_t)(addr >> 0);
281	/* plus 4 "don't care" bytes */
282
283	status = spi_sync(priv->spi, &msg);
284	mutex_unlock(&priv->lock);
285
286	if (status >= 0) {
287		*retlen = msg.actual_length - 8;
288		status = 0;
289	} else
290		DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n",
291			dev_name(&priv->spi->dev),
292			(unsigned)from, (unsigned)(from + len),
293			status);
294	return status;
295}
296
297/*
298 * Write to the DataFlash device.
299 *   to     : Start offset in flash device
300 *   len    : Amount to write
301 *   retlen : Amount of data actually written
302 *   buf    : Buffer containing the data
303 */
304static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
305				size_t * retlen, const u_char * buf)
306{
307	struct dataflash	*priv = mtd->priv;
308	struct spi_device	*spi = priv->spi;
309	struct spi_transfer	x[2] = { { .tx_dma = 0, }, };
310	struct spi_message	msg;
311	unsigned int		pageaddr, addr, offset, writelen;
312	size_t			remaining = len;
313	u_char			*writebuf = (u_char *) buf;
314	int			status = -EINVAL;
315	uint8_t			*command;
316
317	DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n",
318		dev_name(&spi->dev), (unsigned)to, (unsigned)(to + len));
319
320	*retlen = 0;
321
322	/* Sanity checks */
323	if (!len)
324		return 0;
325	if ((to + len) > mtd->size)
326		return -EINVAL;
327
328	spi_message_init(&msg);
329
330	x[0].tx_buf = command = priv->command;
331	x[0].len = 4;
332	spi_message_add_tail(&x[0], &msg);
333
334	pageaddr = ((unsigned)to / priv->page_size);
335	offset = ((unsigned)to % priv->page_size);
336	if (offset + len > priv->page_size)
337		writelen = priv->page_size - offset;
338	else
339		writelen = len;
340
341	mutex_lock(&priv->lock);
342	while (remaining > 0) {
343		DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n",
344			pageaddr, offset, writelen);
345
346		/* REVISIT:
347		 * (a) each page in a sector must be rewritten at least
348		 *     once every 10K sibling erase/program operations.
349		 * (b) for pages that are already erased, we could
350		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
351		 * (c) WRITE to buffer could be done while waiting for
352		 *     a previous MWRITE/MWERASE to complete ...
353		 * (d) error handling here seems to be mostly missing.
354		 *
355		 * Two persistent bits per page, plus a per-sector counter,
356		 * could support (a) and (b) ... we might consider using
357		 * the second half of sector zero, which is just one block,
358		 * to track that state.  (On AT91, that sector should also
359		 * support boot-from-DataFlash.)
360		 */
361
362		addr = pageaddr << priv->page_offset;
363
364		/* (1) Maybe transfer partial page to Buffer1 */
365		if (writelen != priv->page_size) {
366			command[0] = OP_TRANSFER_BUF1;
367			command[1] = (addr & 0x00FF0000) >> 16;
368			command[2] = (addr & 0x0000FF00) >> 8;
369			command[3] = 0;
370
371			DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n",
372				command[0], command[1], command[2], command[3]);
373
374			status = spi_sync(spi, &msg);
375			if (status < 0)
376				DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n",
377					dev_name(&spi->dev), addr, status);
378
379			(void) dataflash_waitready(priv->spi);
380		}
381
382		/* (2) Program full page via Buffer1 */
383		addr += offset;
384		command[0] = OP_PROGRAM_VIA_BUF1;
385		command[1] = (addr & 0x00FF0000) >> 16;
386		command[2] = (addr & 0x0000FF00) >> 8;
387		command[3] = (addr & 0x000000FF);
388
389		DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n",
390			command[0], command[1], command[2], command[3]);
391
392		x[1].tx_buf = writebuf;
393		x[1].len = writelen;
394		spi_message_add_tail(x + 1, &msg);
395		status = spi_sync(spi, &msg);
396		spi_transfer_del(x + 1);
397		if (status < 0)
398			DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n",
399				dev_name(&spi->dev), addr, writelen, status);
400
401		(void) dataflash_waitready(priv->spi);
402
403
404#ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
405
406		/* (3) Compare to Buffer1 */
407		addr = pageaddr << priv->page_offset;
408		command[0] = OP_COMPARE_BUF1;
409		command[1] = (addr & 0x00FF0000) >> 16;
410		command[2] = (addr & 0x0000FF00) >> 8;
411		command[3] = 0;
412
413		DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n",
414			command[0], command[1], command[2], command[3]);
415
416		status = spi_sync(spi, &msg);
417		if (status < 0)
418			DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n",
419				dev_name(&spi->dev), addr, status);
420
421		status = dataflash_waitready(priv->spi);
422
423		/* Check result of the compare operation */
424		if (status & (1 << 6)) {
425			printk(KERN_ERR "%s: compare page %u, err %d\n",
426				dev_name(&spi->dev), pageaddr, status);
427			remaining = 0;
428			status = -EIO;
429			break;
430		} else
431			status = 0;
432
433#endif	/* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
434
435		remaining = remaining - writelen;
436		pageaddr++;
437		offset = 0;
438		writebuf += writelen;
439		*retlen += writelen;
440
441		if (remaining > priv->page_size)
442			writelen = priv->page_size;
443		else
444			writelen = remaining;
445	}
446	mutex_unlock(&priv->lock);
447
448	return status;
449}
450
451/* ......................................................................... */
452
453#ifdef CONFIG_MTD_DATAFLASH_OTP
454
455static int dataflash_get_otp_info(struct mtd_info *mtd,
456		struct otp_info *info, size_t len)
457{
458	/* Report both blocks as identical:  bytes 0..64, locked.
459	 * Unless the user block changed from all-ones, we can't
460	 * tell whether it's still writable; so we assume it isn't.
461	 */
462	info->start = 0;
463	info->length = 64;
464	info->locked = 1;
465	return sizeof(*info);
466}
467
468static ssize_t otp_read(struct spi_device *spi, unsigned base,
469		uint8_t *buf, loff_t off, size_t len)
470{
471	struct spi_message	m;
472	size_t			l;
473	uint8_t			*scratch;
474	struct spi_transfer	t;
475	int			status;
476
477	if (off > 64)
478		return -EINVAL;
479
480	if ((off + len) > 64)
481		len = 64 - off;
482	if (len == 0)
483		return len;
484
485	spi_message_init(&m);
486
487	l = 4 + base + off + len;
488	scratch = kzalloc(l, GFP_KERNEL);
489	if (!scratch)
490		return -ENOMEM;
491
492	/* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
493	 * IN:  ignore 4 bytes, data bytes 0..N (max 127)
494	 */
495	scratch[0] = OP_READ_SECURITY;
496
497	memset(&t, 0, sizeof t);
498	t.tx_buf = scratch;
499	t.rx_buf = scratch;
500	t.len = l;
501	spi_message_add_tail(&t, &m);
502
503	dataflash_waitready(spi);
504
505	status = spi_sync(spi, &m);
506	if (status >= 0) {
507		memcpy(buf, scratch + 4 + base + off, len);
508		status = len;
509	}
510
511	kfree(scratch);
512	return status;
513}
514
515static int dataflash_read_fact_otp(struct mtd_info *mtd,
516		loff_t from, size_t len, size_t *retlen, u_char *buf)
517{
518	struct dataflash	*priv = mtd->priv;
519	int			status;
520
521	/* 64 bytes, from 0..63 ... start at 64 on-chip */
522	mutex_lock(&priv->lock);
523	status = otp_read(priv->spi, 64, buf, from, len);
524	mutex_unlock(&priv->lock);
525
526	if (status < 0)
527		return status;
528	*retlen = status;
529	return 0;
530}
531
532static int dataflash_read_user_otp(struct mtd_info *mtd,
533		loff_t from, size_t len, size_t *retlen, u_char *buf)
534{
535	struct dataflash	*priv = mtd->priv;
536	int			status;
537
538	/* 64 bytes, from 0..63 ... start at 0 on-chip */
539	mutex_lock(&priv->lock);
540	status = otp_read(priv->spi, 0, buf, from, len);
541	mutex_unlock(&priv->lock);
542
543	if (status < 0)
544		return status;
545	*retlen = status;
546	return 0;
547}
548
549static int dataflash_write_user_otp(struct mtd_info *mtd,
550		loff_t from, size_t len, size_t *retlen, u_char *buf)
551{
552	struct spi_message	m;
553	const size_t		l = 4 + 64;
554	uint8_t			*scratch;
555	struct spi_transfer	t;
556	struct dataflash	*priv = mtd->priv;
557	int			status;
558
559	if (len > 64)
560		return -EINVAL;
561
562	/* Strictly speaking, we *could* truncate the write ... but
563	 * let's not do that for the only write that's ever possible.
564	 */
565	if ((from + len) > 64)
566		return -EINVAL;
567
568	/* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
569	 * IN:  ignore all
570	 */
571	scratch = kzalloc(l, GFP_KERNEL);
572	if (!scratch)
573		return -ENOMEM;
574	scratch[0] = OP_WRITE_SECURITY;
575	memcpy(scratch + 4 + from, buf, len);
576
577	spi_message_init(&m);
578
579	memset(&t, 0, sizeof t);
580	t.tx_buf = scratch;
581	t.len = l;
582	spi_message_add_tail(&t, &m);
583
584	/* Write the OTP bits, if they've not yet been written.
585	 * This modifies SRAM buffer1.
586	 */
587	mutex_lock(&priv->lock);
588	dataflash_waitready(priv->spi);
589	status = spi_sync(priv->spi, &m);
590	mutex_unlock(&priv->lock);
591
592	kfree(scratch);
593
594	if (status >= 0) {
595		status = 0;
596		*retlen = len;
597	}
598	return status;
599}
600
601static char *otp_setup(struct mtd_info *device, char revision)
602{
603	device->get_fact_prot_info = dataflash_get_otp_info;
604	device->read_fact_prot_reg = dataflash_read_fact_otp;
605	device->get_user_prot_info = dataflash_get_otp_info;
606	device->read_user_prot_reg = dataflash_read_user_otp;
607
608	/* rev c parts (at45db321c and at45db1281 only!) use a
609	 * different write procedure; not (yet?) implemented.
610	 */
611	if (revision > 'c')
612		device->write_user_prot_reg = dataflash_write_user_otp;
613
614	return ", OTP";
615}
616
617#else
618
619static char *otp_setup(struct mtd_info *device, char revision)
620{
621	return " (OTP)";
622}
623
624#endif
625
626/* ......................................................................... */
627
628/*
629 * Register DataFlash device with MTD subsystem.
630 */
631static int __devinit
632add_dataflash_otp(struct spi_device *spi, char *name,
633		int nr_pages, int pagesize, int pageoffset, char revision)
634{
635	struct dataflash		*priv;
636	struct mtd_info			*device;
637	struct flash_platform_data	*pdata = spi->dev.platform_data;
638	char				*otp_tag = "";
639	int				err = 0;
640
641	priv = kzalloc(sizeof *priv, GFP_KERNEL);
642	if (!priv)
643		return -ENOMEM;
644
645	mutex_init(&priv->lock);
646	priv->spi = spi;
647	priv->page_size = pagesize;
648	priv->page_offset = pageoffset;
649
650	/* name must be usable with cmdlinepart */
651	sprintf(priv->name, "spi%d.%d-%s",
652			spi->master->bus_num, spi->chip_select,
653			name);
654
655	device = &priv->mtd;
656	device->name = (pdata && pdata->name) ? pdata->name : priv->name;
657	device->size = nr_pages * pagesize;
658	device->erasesize = pagesize;
659	device->writesize = pagesize;
660	device->owner = THIS_MODULE;
661	device->type = MTD_DATAFLASH;
662	device->flags = MTD_WRITEABLE;
663	device->erase = dataflash_erase;
664	device->read = dataflash_read;
665	device->write = dataflash_write;
666	device->priv = priv;
667
668	device->dev.parent = &spi->dev;
669
670	if (revision >= 'c')
671		otp_tag = otp_setup(device, revision);
672
673	dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
674			name, (long long)((device->size + 1023) >> 10),
675			pagesize, otp_tag);
676	dev_set_drvdata(&spi->dev, priv);
677
678	if (mtd_has_partitions()) {
679		struct mtd_partition	*parts;
680		int			nr_parts = 0;
681
682		if (mtd_has_cmdlinepart()) {
683			static const char *part_probes[]
684					= { "cmdlinepart", NULL, };
685
686			nr_parts = parse_mtd_partitions(device,
687					part_probes, &parts, 0);
688		}
689
690		if (nr_parts <= 0 && pdata && pdata->parts) {
691			parts = pdata->parts;
692			nr_parts = pdata->nr_parts;
693		}
694
695		if (nr_parts > 0) {
696			priv->partitioned = 1;
697			err = add_mtd_partitions(device, parts, nr_parts);
698			goto out;
699		}
700	} else if (pdata && pdata->nr_parts)
701		dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
702				pdata->nr_parts, device->name);
703
704	if (add_mtd_device(device) == 1)
705		err = -ENODEV;
706
707out:
708	if (!err)
709		return 0;
710
711	dev_set_drvdata(&spi->dev, NULL);
712	kfree(priv);
713	return err;
714}
715
716static inline int __devinit
717add_dataflash(struct spi_device *spi, char *name,
718		int nr_pages, int pagesize, int pageoffset)
719{
720	return add_dataflash_otp(spi, name, nr_pages, pagesize,
721			pageoffset, 0);
722}
723
724struct flash_info {
725	char		*name;
726
727	/* JEDEC id has a high byte of zero plus three data bytes:
728	 * the manufacturer id, then a two byte device id.
729	 */
730	uint32_t	jedec_id;
731
732	/* The size listed here is what works with OP_ERASE_PAGE. */
733	unsigned	nr_pages;
734	uint16_t	pagesize;
735	uint16_t	pageoffset;
736
737	uint16_t	flags;
738#define SUP_POW2PS	0x0002		/* supports 2^N byte pages */
739#define IS_POW2PS	0x0001		/* uses 2^N byte pages */
740};
741
742static struct flash_info __devinitdata dataflash_data [] = {
743
744	/*
745	 * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
746	 * one with IS_POW2PS and the other without.  The entry with the
747	 * non-2^N byte page size can't name exact chip revisions without
748	 * losing backwards compatibility for cmdlinepart.
749	 *
750	 * These newer chips also support 128-byte security registers (with
751	 * 64 bytes one-time-programmable) and software write-protection.
752	 */
753	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
754	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
755
756	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
757	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
758
759	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
760	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
761
762	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
763	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
764
765	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
766	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
767
768	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
769
770	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
771	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
772
773	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
774	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
775};
776
777static struct flash_info *__devinit jedec_probe(struct spi_device *spi)
778{
779	int			tmp;
780	uint8_t			code = OP_READ_ID;
781	uint8_t			id[3];
782	uint32_t		jedec;
783	struct flash_info	*info;
784	int status;
785
786	/* JEDEC also defines an optional "extended device information"
787	 * string for after vendor-specific data, after the three bytes
788	 * we use here.  Supporting some chips might require using it.
789	 *
790	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
791	 * That's not an error; only rev C and newer chips handle it, and
792	 * only Atmel sells these chips.
793	 */
794	tmp = spi_write_then_read(spi, &code, 1, id, 3);
795	if (tmp < 0) {
796		DEBUG(MTD_DEBUG_LEVEL0, "%s: error %d reading JEDEC ID\n",
797			dev_name(&spi->dev), tmp);
798		return ERR_PTR(tmp);
799	}
800	if (id[0] != 0x1f)
801		return NULL;
802
803	jedec = id[0];
804	jedec = jedec << 8;
805	jedec |= id[1];
806	jedec = jedec << 8;
807	jedec |= id[2];
808
809	for (tmp = 0, info = dataflash_data;
810			tmp < ARRAY_SIZE(dataflash_data);
811			tmp++, info++) {
812		if (info->jedec_id == jedec) {
813			DEBUG(MTD_DEBUG_LEVEL1, "%s: OTP, sector protect%s\n",
814				dev_name(&spi->dev),
815				(info->flags & SUP_POW2PS)
816					? ", binary pagesize" : ""
817				);
818			if (info->flags & SUP_POW2PS) {
819				status = dataflash_status(spi);
820				if (status < 0) {
821					DEBUG(MTD_DEBUG_LEVEL1,
822						"%s: status error %d\n",
823						dev_name(&spi->dev), status);
824					return ERR_PTR(status);
825				}
826				if (status & 0x1) {
827					if (info->flags & IS_POW2PS)
828						return info;
829				} else {
830					if (!(info->flags & IS_POW2PS))
831						return info;
832				}
833			} else
834				return info;
835		}
836	}
837
838	/*
839	 * Treat other chips as errors ... we won't know the right page
840	 * size (it might be binary) even when we can tell which density
841	 * class is involved (legacy chip id scheme).
842	 */
843	dev_warn(&spi->dev, "JEDEC id %06x not handled\n", jedec);
844	return ERR_PTR(-ENODEV);
845}
846
847/*
848 * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
849 * or else the ID code embedded in the status bits:
850 *
851 *   Device      Density         ID code          #Pages PageSize  Offset
852 *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
853 *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
854 *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
855 *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
856 *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
857 *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
858 *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
859 *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
860 */
861static int __devinit dataflash_probe(struct spi_device *spi)
862{
863	int status;
864	struct flash_info	*info;
865
866	/*
867	 * Try to detect dataflash by JEDEC ID.
868	 * If it succeeds we know we have either a C or D part.
869	 * D will support power of 2 pagesize option.
870	 * Both support the security register, though with different
871	 * write procedures.
872	 */
873	info = jedec_probe(spi);
874	if (IS_ERR(info))
875		return PTR_ERR(info);
876	if (info != NULL)
877		return add_dataflash_otp(spi, info->name, info->nr_pages,
878				info->pagesize, info->pageoffset,
879				(info->flags & SUP_POW2PS) ? 'd' : 'c');
880
881	/*
882	 * Older chips support only legacy commands, identifing
883	 * capacity using bits in the status byte.
884	 */
885	status = dataflash_status(spi);
886	if (status <= 0 || status == 0xff) {
887		DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n",
888				dev_name(&spi->dev), status);
889		if (status == 0 || status == 0xff)
890			status = -ENODEV;
891		return status;
892	}
893
894	/* if there's a device there, assume it's dataflash.
895	 * board setup should have set spi->max_speed_max to
896	 * match f(car) for continuous reads, mode 0 or 3.
897	 */
898	switch (status & 0x3c) {
899	case 0x0c:	/* 0 0 1 1 x x */
900		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
901		break;
902	case 0x14:	/* 0 1 0 1 x x */
903		status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
904		break;
905	case 0x1c:	/* 0 1 1 1 x x */
906		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
907		break;
908	case 0x24:	/* 1 0 0 1 x x */
909		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
910		break;
911	case 0x2c:	/* 1 0 1 1 x x */
912		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
913		break;
914	case 0x34:	/* 1 1 0 1 x x */
915		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
916		break;
917	case 0x38:	/* 1 1 1 x x x */
918	case 0x3c:
919		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
920		break;
921	/* obsolete AT45DB1282 not (yet?) supported */
922	default:
923		DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n",
924				dev_name(&spi->dev), status & 0x3c);
925		status = -ENODEV;
926	}
927
928	if (status < 0)
929		DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n",
930				dev_name(&spi->dev), status);
931
932	return status;
933}
934
935static int __devexit dataflash_remove(struct spi_device *spi)
936{
937	struct dataflash	*flash = dev_get_drvdata(&spi->dev);
938	int			status;
939
940	DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", dev_name(&spi->dev));
941
942	if (mtd_has_partitions() && flash->partitioned)
943		status = del_mtd_partitions(&flash->mtd);
944	else
945		status = del_mtd_device(&flash->mtd);
946	if (status == 0) {
947		dev_set_drvdata(&spi->dev, NULL);
948		kfree(flash);
949	}
950	return status;
951}
952
953static struct spi_driver dataflash_driver = {
954	.driver = {
955		.name		= "mtd_dataflash",
956		.bus		= &spi_bus_type,
957		.owner		= THIS_MODULE,
958	},
959
960	.probe		= dataflash_probe,
961	.remove		= __devexit_p(dataflash_remove),
962
963};
964
965static int __init dataflash_init(void)
966{
967	return spi_register_driver(&dataflash_driver);
968}
969module_init(dataflash_init);
970
971static void __exit dataflash_exit(void)
972{
973	spi_unregister_driver(&dataflash_driver);
974}
975module_exit(dataflash_exit);
976
977
978MODULE_LICENSE("GPL");
979MODULE_AUTHOR("Andrew Victor, David Brownell");
980MODULE_DESCRIPTION("MTD DataFlash driver");
981MODULE_ALIAS("spi:mtd_dataflash");
982