1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework
4 *
5 * Largely derived from at91_dataflash.c:
6 *  Copyright (C) 2003-2005 SAN People (Pty) Ltd
7*/
8#include <linux/module.h>
9#include <linux/slab.h>
10#include <linux/delay.h>
11#include <linux/device.h>
12#include <linux/mutex.h>
13#include <linux/err.h>
14#include <linux/math64.h>
15#include <linux/of.h>
16
17#include <linux/spi/spi.h>
18#include <linux/spi/flash.h>
19
20#include <linux/mtd/mtd.h>
21#include <linux/mtd/partitions.h>
22
23/*
24 * DataFlash is a kind of SPI flash.  Most AT45 chips have two buffers in
25 * each chip, which may be used for double buffered I/O; but this driver
26 * doesn't (yet) use these for any kind of i/o overlap or prefetching.
27 *
28 * Sometimes DataFlash is packaged in MMC-format cards, although the
29 * MMC stack can't (yet?) distinguish between MMC and DataFlash
30 * protocols during enumeration.
31 */
32
33/* reads can bypass the buffers */
34#define OP_READ_CONTINUOUS	0xE8
35#define OP_READ_PAGE		0xD2
36
37/* group B requests can run even while status reports "busy" */
38#define OP_READ_STATUS		0xD7	/* group B */
39
40/* move data between host and buffer */
41#define OP_READ_BUFFER1		0xD4	/* group B */
42#define OP_READ_BUFFER2		0xD6	/* group B */
43#define OP_WRITE_BUFFER1	0x84	/* group B */
44#define OP_WRITE_BUFFER2	0x87	/* group B */
45
46/* erasing flash */
47#define OP_ERASE_PAGE		0x81
48#define OP_ERASE_BLOCK		0x50
49
50/* move data between buffer and flash */
51#define OP_TRANSFER_BUF1	0x53
52#define OP_TRANSFER_BUF2	0x55
53#define OP_MREAD_BUFFER1	0xD4
54#define OP_MREAD_BUFFER2	0xD6
55#define OP_MWERASE_BUFFER1	0x83
56#define OP_MWERASE_BUFFER2	0x86
57#define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
58#define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */
59
60/* write to buffer, then write-erase to flash */
61#define OP_PROGRAM_VIA_BUF1	0x82
62#define OP_PROGRAM_VIA_BUF2	0x85
63
64/* compare buffer to flash */
65#define OP_COMPARE_BUF1		0x60
66#define OP_COMPARE_BUF2		0x61
67
68/* read flash to buffer, then write-erase to flash */
69#define OP_REWRITE_VIA_BUF1	0x58
70#define OP_REWRITE_VIA_BUF2	0x59
71
72/* newer chips report JEDEC manufacturer and device IDs; chip
73 * serial number and OTP bits; and per-sector writeprotect.
74 */
75#define OP_READ_ID		0x9F
76#define OP_READ_SECURITY	0x77
77#define OP_WRITE_SECURITY_REVC	0x9A
78#define OP_WRITE_SECURITY	0x9B	/* revision D */
79
80#define CFI_MFR_ATMEL		0x1F
81
82#define DATAFLASH_SHIFT_EXTID	24
83#define DATAFLASH_SHIFT_ID	40
84
85struct dataflash {
86	u8			command[4];
87	char			name[24];
88
89	unsigned short		page_offset;	/* offset in flash address */
90	unsigned int		page_size;	/* of bytes per page */
91
92	struct mutex		lock;
93	struct spi_device	*spi;
94
95	struct mtd_info		mtd;
96};
97
98#ifdef CONFIG_OF
99static const struct of_device_id dataflash_dt_ids[] = {
100	{ .compatible = "atmel,at45", },
101	{ .compatible = "atmel,dataflash", },
102	{ /* sentinel */ }
103};
104MODULE_DEVICE_TABLE(of, dataflash_dt_ids);
105#endif
106
107static const struct spi_device_id dataflash_spi_ids[] = {
108	{ .name = "at45", },
109	{ .name = "dataflash", },
110	{ /* sentinel */ }
111};
112MODULE_DEVICE_TABLE(spi, dataflash_spi_ids);
113
114/* ......................................................................... */
115
116/*
117 * Return the status of the DataFlash device.
118 */
119static inline int dataflash_status(struct spi_device *spi)
120{
121	/* NOTE:  at45db321c over 25 MHz wants to write
122	 * a dummy byte after the opcode...
123	 */
124	return spi_w8r8(spi, OP_READ_STATUS);
125}
126
127/*
128 * Poll the DataFlash device until it is READY.
129 * This usually takes 5-20 msec or so; more for sector erase.
130 */
131static int dataflash_waitready(struct spi_device *spi)
132{
133	int	status;
134
135	for (;;) {
136		status = dataflash_status(spi);
137		if (status < 0) {
138			dev_dbg(&spi->dev, "status %d?\n", status);
139			status = 0;
140		}
141
142		if (status & (1 << 7))	/* RDY/nBSY */
143			return status;
144
145		usleep_range(3000, 4000);
146	}
147}
148
149/* ......................................................................... */
150
151/*
152 * Erase pages of flash.
153 */
154static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
155{
156	struct dataflash	*priv = mtd->priv;
157	struct spi_device	*spi = priv->spi;
158	struct spi_transfer	x = { };
159	struct spi_message	msg;
160	unsigned		blocksize = priv->page_size << 3;
161	u8			*command;
162	u32			rem;
163
164	dev_dbg(&spi->dev, "erase addr=0x%llx len 0x%llx\n",
165		(long long)instr->addr, (long long)instr->len);
166
167	div_u64_rem(instr->len, priv->page_size, &rem);
168	if (rem)
169		return -EINVAL;
170	div_u64_rem(instr->addr, priv->page_size, &rem);
171	if (rem)
172		return -EINVAL;
173
174	spi_message_init(&msg);
175
176	x.tx_buf = command = priv->command;
177	x.len = 4;
178	spi_message_add_tail(&x, &msg);
179
180	mutex_lock(&priv->lock);
181	while (instr->len > 0) {
182		unsigned int	pageaddr;
183		int		status;
184		int		do_block;
185
186		/* Calculate flash page address; use block erase (for speed) if
187		 * we're at a block boundary and need to erase the whole block.
188		 */
189		pageaddr = div_u64(instr->addr, priv->page_size);
190		do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize;
191		pageaddr = pageaddr << priv->page_offset;
192
193		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
194		command[1] = (u8)(pageaddr >> 16);
195		command[2] = (u8)(pageaddr >> 8);
196		command[3] = 0;
197
198		dev_dbg(&spi->dev, "ERASE %s: (%x) %x %x %x [%i]\n",
199			do_block ? "block" : "page",
200			command[0], command[1], command[2], command[3],
201			pageaddr);
202
203		status = spi_sync(spi, &msg);
204		(void) dataflash_waitready(spi);
205
206		if (status < 0) {
207			dev_err(&spi->dev, "erase %x, err %d\n",
208				pageaddr, status);
209			/* REVISIT:  can retry instr->retries times; or
210			 * giveup and instr->fail_addr = instr->addr;
211			 */
212			continue;
213		}
214
215		if (do_block) {
216			instr->addr += blocksize;
217			instr->len -= blocksize;
218		} else {
219			instr->addr += priv->page_size;
220			instr->len -= priv->page_size;
221		}
222	}
223	mutex_unlock(&priv->lock);
224
225	return 0;
226}
227
228/*
229 * Read from the DataFlash device.
230 *   from   : Start offset in flash device
231 *   len    : Amount to read
232 *   retlen : About of data actually read
233 *   buf    : Buffer containing the data
234 */
235static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
236			       size_t *retlen, u_char *buf)
237{
238	struct dataflash	*priv = mtd->priv;
239	struct spi_transfer	x[2] = { };
240	struct spi_message	msg;
241	unsigned int		addr;
242	u8			*command;
243	int			status;
244
245	dev_dbg(&priv->spi->dev, "read 0x%x..0x%x\n",
246		  (unsigned int)from, (unsigned int)(from + len));
247
248	/* Calculate flash page/byte address */
249	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
250		+ ((unsigned)from % priv->page_size);
251
252	command = priv->command;
253
254	dev_dbg(&priv->spi->dev, "READ: (%x) %x %x %x\n",
255		command[0], command[1], command[2], command[3]);
256
257	spi_message_init(&msg);
258
259	x[0].tx_buf = command;
260	x[0].len = 8;
261	spi_message_add_tail(&x[0], &msg);
262
263	x[1].rx_buf = buf;
264	x[1].len = len;
265	spi_message_add_tail(&x[1], &msg);
266
267	mutex_lock(&priv->lock);
268
269	/* Continuous read, max clock = f(car) which may be less than
270	 * the peak rate available.  Some chips support commands with
271	 * fewer "don't care" bytes.  Both buffers stay unchanged.
272	 */
273	command[0] = OP_READ_CONTINUOUS;
274	command[1] = (u8)(addr >> 16);
275	command[2] = (u8)(addr >> 8);
276	command[3] = (u8)(addr >> 0);
277	/* plus 4 "don't care" bytes */
278
279	status = spi_sync(priv->spi, &msg);
280	mutex_unlock(&priv->lock);
281
282	if (status >= 0) {
283		*retlen = msg.actual_length - 8;
284		status = 0;
285	} else
286		dev_dbg(&priv->spi->dev, "read %x..%x --> %d\n",
287			(unsigned)from, (unsigned)(from + len),
288			status);
289	return status;
290}
291
292/*
293 * Write to the DataFlash device.
294 *   to     : Start offset in flash device
295 *   len    : Amount to write
296 *   retlen : Amount of data actually written
297 *   buf    : Buffer containing the data
298 */
299static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
300				size_t * retlen, const u_char * buf)
301{
302	struct dataflash	*priv = mtd->priv;
303	struct spi_device	*spi = priv->spi;
304	struct spi_transfer	x[2] = { };
305	struct spi_message	msg;
306	unsigned int		pageaddr, addr, offset, writelen;
307	size_t			remaining = len;
308	u_char			*writebuf = (u_char *) buf;
309	int			status = -EINVAL;
310	u8			*command;
311
312	dev_dbg(&spi->dev, "write 0x%x..0x%x\n",
313		(unsigned int)to, (unsigned int)(to + len));
314
315	spi_message_init(&msg);
316
317	x[0].tx_buf = command = priv->command;
318	x[0].len = 4;
319	spi_message_add_tail(&x[0], &msg);
320
321	pageaddr = ((unsigned)to / priv->page_size);
322	offset = ((unsigned)to % priv->page_size);
323	if (offset + len > priv->page_size)
324		writelen = priv->page_size - offset;
325	else
326		writelen = len;
327
328	mutex_lock(&priv->lock);
329	while (remaining > 0) {
330		dev_dbg(&spi->dev, "write @ %i:%i len=%i\n",
331			pageaddr, offset, writelen);
332
333		/* REVISIT:
334		 * (a) each page in a sector must be rewritten at least
335		 *     once every 10K sibling erase/program operations.
336		 * (b) for pages that are already erased, we could
337		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
338		 * (c) WRITE to buffer could be done while waiting for
339		 *     a previous MWRITE/MWERASE to complete ...
340		 * (d) error handling here seems to be mostly missing.
341		 *
342		 * Two persistent bits per page, plus a per-sector counter,
343		 * could support (a) and (b) ... we might consider using
344		 * the second half of sector zero, which is just one block,
345		 * to track that state.  (On AT91, that sector should also
346		 * support boot-from-DataFlash.)
347		 */
348
349		addr = pageaddr << priv->page_offset;
350
351		/* (1) Maybe transfer partial page to Buffer1 */
352		if (writelen != priv->page_size) {
353			command[0] = OP_TRANSFER_BUF1;
354			command[1] = (addr & 0x00FF0000) >> 16;
355			command[2] = (addr & 0x0000FF00) >> 8;
356			command[3] = 0;
357
358			dev_dbg(&spi->dev, "TRANSFER: (%x) %x %x %x\n",
359				command[0], command[1], command[2], command[3]);
360
361			status = spi_sync(spi, &msg);
362			if (status < 0)
363				dev_dbg(&spi->dev, "xfer %u -> %d\n",
364					addr, status);
365
366			(void) dataflash_waitready(priv->spi);
367		}
368
369		/* (2) Program full page via Buffer1 */
370		addr += offset;
371		command[0] = OP_PROGRAM_VIA_BUF1;
372		command[1] = (addr & 0x00FF0000) >> 16;
373		command[2] = (addr & 0x0000FF00) >> 8;
374		command[3] = (addr & 0x000000FF);
375
376		dev_dbg(&spi->dev, "PROGRAM: (%x) %x %x %x\n",
377			command[0], command[1], command[2], command[3]);
378
379		x[1].tx_buf = writebuf;
380		x[1].len = writelen;
381		spi_message_add_tail(x + 1, &msg);
382		status = spi_sync(spi, &msg);
383		spi_transfer_del(x + 1);
384		if (status < 0)
385			dev_dbg(&spi->dev, "pgm %u/%u -> %d\n",
386				addr, writelen, status);
387
388		(void) dataflash_waitready(priv->spi);
389
390
391#ifdef CONFIG_MTD_DATAFLASH_WRITE_VERIFY
392
393		/* (3) Compare to Buffer1 */
394		addr = pageaddr << priv->page_offset;
395		command[0] = OP_COMPARE_BUF1;
396		command[1] = (addr & 0x00FF0000) >> 16;
397		command[2] = (addr & 0x0000FF00) >> 8;
398		command[3] = 0;
399
400		dev_dbg(&spi->dev, "COMPARE: (%x) %x %x %x\n",
401			command[0], command[1], command[2], command[3]);
402
403		status = spi_sync(spi, &msg);
404		if (status < 0)
405			dev_dbg(&spi->dev, "compare %u -> %d\n",
406				addr, status);
407
408		status = dataflash_waitready(priv->spi);
409
410		/* Check result of the compare operation */
411		if (status & (1 << 6)) {
412			dev_err(&spi->dev, "compare page %u, err %d\n",
413				pageaddr, status);
414			remaining = 0;
415			status = -EIO;
416			break;
417		} else
418			status = 0;
419
420#endif	/* CONFIG_MTD_DATAFLASH_WRITE_VERIFY */
421
422		remaining = remaining - writelen;
423		pageaddr++;
424		offset = 0;
425		writebuf += writelen;
426		*retlen += writelen;
427
428		if (remaining > priv->page_size)
429			writelen = priv->page_size;
430		else
431			writelen = remaining;
432	}
433	mutex_unlock(&priv->lock);
434
435	return status;
436}
437
438/* ......................................................................... */
439
440#ifdef CONFIG_MTD_DATAFLASH_OTP
441
442static int dataflash_get_otp_info(struct mtd_info *mtd, size_t len,
443				  size_t *retlen, struct otp_info *info)
444{
445	/* Report both blocks as identical:  bytes 0..64, locked.
446	 * Unless the user block changed from all-ones, we can't
447	 * tell whether it's still writable; so we assume it isn't.
448	 */
449	info->start = 0;
450	info->length = 64;
451	info->locked = 1;
452	*retlen = sizeof(*info);
453	return 0;
454}
455
456static ssize_t otp_read(struct spi_device *spi, unsigned base,
457		u8 *buf, loff_t off, size_t len)
458{
459	struct spi_message	m;
460	size_t			l;
461	u8			*scratch;
462	struct spi_transfer	t;
463	int			status;
464
465	if (off > 64)
466		return -EINVAL;
467
468	if ((off + len) > 64)
469		len = 64 - off;
470
471	spi_message_init(&m);
472
473	l = 4 + base + off + len;
474	scratch = kzalloc(l, GFP_KERNEL);
475	if (!scratch)
476		return -ENOMEM;
477
478	/* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes
479	 * IN:  ignore 4 bytes, data bytes 0..N (max 127)
480	 */
481	scratch[0] = OP_READ_SECURITY;
482
483	memset(&t, 0, sizeof t);
484	t.tx_buf = scratch;
485	t.rx_buf = scratch;
486	t.len = l;
487	spi_message_add_tail(&t, &m);
488
489	dataflash_waitready(spi);
490
491	status = spi_sync(spi, &m);
492	if (status >= 0) {
493		memcpy(buf, scratch + 4 + base + off, len);
494		status = len;
495	}
496
497	kfree(scratch);
498	return status;
499}
500
501static int dataflash_read_fact_otp(struct mtd_info *mtd,
502		loff_t from, size_t len, size_t *retlen, u_char *buf)
503{
504	struct dataflash	*priv = mtd->priv;
505	int			status;
506
507	/* 64 bytes, from 0..63 ... start at 64 on-chip */
508	mutex_lock(&priv->lock);
509	status = otp_read(priv->spi, 64, buf, from, len);
510	mutex_unlock(&priv->lock);
511
512	if (status < 0)
513		return status;
514	*retlen = status;
515	return 0;
516}
517
518static int dataflash_read_user_otp(struct mtd_info *mtd,
519		loff_t from, size_t len, size_t *retlen, u_char *buf)
520{
521	struct dataflash	*priv = mtd->priv;
522	int			status;
523
524	/* 64 bytes, from 0..63 ... start at 0 on-chip */
525	mutex_lock(&priv->lock);
526	status = otp_read(priv->spi, 0, buf, from, len);
527	mutex_unlock(&priv->lock);
528
529	if (status < 0)
530		return status;
531	*retlen = status;
532	return 0;
533}
534
535static int dataflash_write_user_otp(struct mtd_info *mtd,
536		loff_t from, size_t len, size_t *retlen, const u_char *buf)
537{
538	struct spi_message	m;
539	const size_t		l = 4 + 64;
540	u8			*scratch;
541	struct spi_transfer	t;
542	struct dataflash	*priv = mtd->priv;
543	int			status;
544
545	if (from >= 64) {
546		/*
547		 * Attempting to write beyond the end of OTP memory,
548		 * no data can be written.
549		 */
550		*retlen = 0;
551		return 0;
552	}
553
554	/* Truncate the write to fit into OTP memory. */
555	if ((from + len) > 64)
556		len = 64 - from;
557
558	/* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes
559	 * IN:  ignore all
560	 */
561	scratch = kzalloc(l, GFP_KERNEL);
562	if (!scratch)
563		return -ENOMEM;
564	scratch[0] = OP_WRITE_SECURITY;
565	memcpy(scratch + 4 + from, buf, len);
566
567	spi_message_init(&m);
568
569	memset(&t, 0, sizeof t);
570	t.tx_buf = scratch;
571	t.len = l;
572	spi_message_add_tail(&t, &m);
573
574	/* Write the OTP bits, if they've not yet been written.
575	 * This modifies SRAM buffer1.
576	 */
577	mutex_lock(&priv->lock);
578	dataflash_waitready(priv->spi);
579	status = spi_sync(priv->spi, &m);
580	mutex_unlock(&priv->lock);
581
582	kfree(scratch);
583
584	if (status >= 0) {
585		status = 0;
586		*retlen = len;
587	}
588	return status;
589}
590
591static char *otp_setup(struct mtd_info *device, char revision)
592{
593	device->_get_fact_prot_info = dataflash_get_otp_info;
594	device->_read_fact_prot_reg = dataflash_read_fact_otp;
595	device->_get_user_prot_info = dataflash_get_otp_info;
596	device->_read_user_prot_reg = dataflash_read_user_otp;
597
598	/* rev c parts (at45db321c and at45db1281 only!) use a
599	 * different write procedure; not (yet?) implemented.
600	 */
601	if (revision > 'c')
602		device->_write_user_prot_reg = dataflash_write_user_otp;
603
604	return ", OTP";
605}
606
607#else
608
609static char *otp_setup(struct mtd_info *device, char revision)
610{
611	return " (OTP)";
612}
613
614#endif
615
616/* ......................................................................... */
617
618/*
619 * Register DataFlash device with MTD subsystem.
620 */
621static int add_dataflash_otp(struct spi_device *spi, char *name, int nr_pages,
622			     int pagesize, int pageoffset, char revision)
623{
624	struct dataflash		*priv;
625	struct mtd_info			*device;
626	struct flash_platform_data	*pdata = dev_get_platdata(&spi->dev);
627	char				*otp_tag = "";
628	int				err = 0;
629
630	priv = kzalloc(sizeof *priv, GFP_KERNEL);
631	if (!priv)
632		return -ENOMEM;
633
634	mutex_init(&priv->lock);
635	priv->spi = spi;
636	priv->page_size = pagesize;
637	priv->page_offset = pageoffset;
638
639	/* name must be usable with cmdlinepart */
640	sprintf(priv->name, "spi%d.%d-%s",
641			spi->controller->bus_num, spi_get_chipselect(spi, 0),
642			name);
643
644	device = &priv->mtd;
645	device->name = (pdata && pdata->name) ? pdata->name : priv->name;
646	device->size = nr_pages * pagesize;
647	device->erasesize = pagesize;
648	device->writesize = pagesize;
649	device->type = MTD_DATAFLASH;
650	device->flags = MTD_WRITEABLE;
651	device->_erase = dataflash_erase;
652	device->_read = dataflash_read;
653	device->_write = dataflash_write;
654	device->priv = priv;
655
656	device->dev.parent = &spi->dev;
657	mtd_set_of_node(device, spi->dev.of_node);
658
659	if (revision >= 'c')
660		otp_tag = otp_setup(device, revision);
661
662	dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n",
663			name, (long long)((device->size + 1023) >> 10),
664			pagesize, otp_tag);
665	spi_set_drvdata(spi, priv);
666
667	err = mtd_device_register(device,
668			pdata ? pdata->parts : NULL,
669			pdata ? pdata->nr_parts : 0);
670
671	if (!err)
672		return 0;
673
674	kfree(priv);
675	return err;
676}
677
678static inline int add_dataflash(struct spi_device *spi, char *name,
679				int nr_pages, int pagesize, int pageoffset)
680{
681	return add_dataflash_otp(spi, name, nr_pages, pagesize,
682			pageoffset, 0);
683}
684
685struct flash_info {
686	char		*name;
687
688	/* JEDEC id has a high byte of zero plus three data bytes:
689	 * the manufacturer id, then a two byte device id.
690	 */
691	u64		jedec_id;
692
693	/* The size listed here is what works with OP_ERASE_PAGE. */
694	unsigned	nr_pages;
695	u16		pagesize;
696	u16		pageoffset;
697
698	u16		flags;
699#define SUP_EXTID	0x0004		/* supports extended ID data */
700#define SUP_POW2PS	0x0002		/* supports 2^N byte pages */
701#define IS_POW2PS	0x0001		/* uses 2^N byte pages */
702};
703
704static struct flash_info dataflash_data[] = {
705
706	/*
707	 * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
708	 * one with IS_POW2PS and the other without.  The entry with the
709	 * non-2^N byte page size can't name exact chip revisions without
710	 * losing backwards compatibility for cmdlinepart.
711	 *
712	 * These newer chips also support 128-byte security registers (with
713	 * 64 bytes one-time-programmable) and software write-protection.
714	 */
715	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
716	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
717
718	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
719	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
720
721	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
722	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
723
724	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
725	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
726
727	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
728	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
729
730	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
731
732	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
733	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
734
735	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
736	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
737
738	{ "AT45DB641E",  0x1f28000100ULL, 32768, 264, 9, SUP_EXTID | SUP_POW2PS},
739	{ "at45db641e",  0x1f28000100ULL, 32768, 256, 8, SUP_EXTID | SUP_POW2PS | IS_POW2PS},
740};
741
742static struct flash_info *jedec_lookup(struct spi_device *spi,
743				       u64 jedec, bool use_extid)
744{
745	struct flash_info *info;
746	int status;
747
748	for (info = dataflash_data;
749	     info < dataflash_data + ARRAY_SIZE(dataflash_data);
750	     info++) {
751		if (use_extid && !(info->flags & SUP_EXTID))
752			continue;
753
754		if (info->jedec_id == jedec) {
755			dev_dbg(&spi->dev, "OTP, sector protect%s\n",
756				(info->flags & SUP_POW2PS) ?
757				", binary pagesize" : "");
758			if (info->flags & SUP_POW2PS) {
759				status = dataflash_status(spi);
760				if (status < 0) {
761					dev_dbg(&spi->dev, "status error %d\n",
762						status);
763					return ERR_PTR(status);
764				}
765				if (status & 0x1) {
766					if (info->flags & IS_POW2PS)
767						return info;
768				} else {
769					if (!(info->flags & IS_POW2PS))
770						return info;
771				}
772			} else
773				return info;
774		}
775	}
776
777	return ERR_PTR(-ENODEV);
778}
779
780static struct flash_info *jedec_probe(struct spi_device *spi)
781{
782	int ret;
783	u8 code = OP_READ_ID;
784	u64 jedec;
785	u8 id[sizeof(jedec)] = {0};
786	const unsigned int id_size = 5;
787	struct flash_info *info;
788
789	/*
790	 * JEDEC also defines an optional "extended device information"
791	 * string for after vendor-specific data, after the three bytes
792	 * we use here.  Supporting some chips might require using it.
793	 *
794	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
795	 * That's not an error; only rev C and newer chips handle it, and
796	 * only Atmel sells these chips.
797	 */
798	ret = spi_write_then_read(spi, &code, 1, id, id_size);
799	if (ret < 0) {
800		dev_dbg(&spi->dev, "error %d reading JEDEC ID\n", ret);
801		return ERR_PTR(ret);
802	}
803
804	if (id[0] != CFI_MFR_ATMEL)
805		return NULL;
806
807	jedec = be64_to_cpup((__be64 *)id);
808
809	/*
810	 * First, try to match device using extended device
811	 * information
812	 */
813	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_EXTID, true);
814	if (!IS_ERR(info))
815		return info;
816	/*
817	 * If that fails, make another pass using regular ID
818	 * information
819	 */
820	info = jedec_lookup(spi, jedec >> DATAFLASH_SHIFT_ID, false);
821	if (!IS_ERR(info))
822		return info;
823	/*
824	 * Treat other chips as errors ... we won't know the right page
825	 * size (it might be binary) even when we can tell which density
826	 * class is involved (legacy chip id scheme).
827	 */
828	dev_warn(&spi->dev, "JEDEC id %016llx not handled\n", jedec);
829	return ERR_PTR(-ENODEV);
830}
831
832/*
833 * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
834 * or else the ID code embedded in the status bits:
835 *
836 *   Device      Density         ID code          #Pages PageSize  Offset
837 *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
838 *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
839 *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
840 *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
841 *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
842 *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
843 *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
844 *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
845 */
846static int dataflash_probe(struct spi_device *spi)
847{
848	int status;
849	struct flash_info	*info;
850
851	/*
852	 * Try to detect dataflash by JEDEC ID.
853	 * If it succeeds we know we have either a C or D part.
854	 * D will support power of 2 pagesize option.
855	 * Both support the security register, though with different
856	 * write procedures.
857	 */
858	info = jedec_probe(spi);
859	if (IS_ERR(info))
860		return PTR_ERR(info);
861	if (info != NULL)
862		return add_dataflash_otp(spi, info->name, info->nr_pages,
863				info->pagesize, info->pageoffset,
864				(info->flags & SUP_POW2PS) ? 'd' : 'c');
865
866	/*
867	 * Older chips support only legacy commands, identifing
868	 * capacity using bits in the status byte.
869	 */
870	status = dataflash_status(spi);
871	if (status <= 0 || status == 0xff) {
872		dev_dbg(&spi->dev, "status error %d\n", status);
873		if (status == 0 || status == 0xff)
874			status = -ENODEV;
875		return status;
876	}
877
878	/* if there's a device there, assume it's dataflash.
879	 * board setup should have set spi->max_speed_max to
880	 * match f(car) for continuous reads, mode 0 or 3.
881	 */
882	switch (status & 0x3c) {
883	case 0x0c:	/* 0 0 1 1 x x */
884		status = add_dataflash(spi, "AT45DB011B", 512, 264, 9);
885		break;
886	case 0x14:	/* 0 1 0 1 x x */
887		status = add_dataflash(spi, "AT45DB021B", 1024, 264, 9);
888		break;
889	case 0x1c:	/* 0 1 1 1 x x */
890		status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9);
891		break;
892	case 0x24:	/* 1 0 0 1 x x */
893		status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9);
894		break;
895	case 0x2c:	/* 1 0 1 1 x x */
896		status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10);
897		break;
898	case 0x34:	/* 1 1 0 1 x x */
899		status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10);
900		break;
901	case 0x38:	/* 1 1 1 x x x */
902	case 0x3c:
903		status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11);
904		break;
905	/* obsolete AT45DB1282 not (yet?) supported */
906	default:
907		dev_info(&spi->dev, "unsupported device (%x)\n",
908				status & 0x3c);
909		status = -ENODEV;
910	}
911
912	if (status < 0)
913		dev_dbg(&spi->dev, "add_dataflash --> %d\n", status);
914
915	return status;
916}
917
918static void dataflash_remove(struct spi_device *spi)
919{
920	struct dataflash	*flash = spi_get_drvdata(spi);
921
922	dev_dbg(&spi->dev, "remove\n");
923
924	WARN_ON(mtd_device_unregister(&flash->mtd));
925
926	kfree(flash);
927}
928
929static struct spi_driver dataflash_driver = {
930	.driver = {
931		.name		= "mtd_dataflash",
932		.of_match_table = of_match_ptr(dataflash_dt_ids),
933	},
934	.probe		= dataflash_probe,
935	.remove		= dataflash_remove,
936	.id_table	= dataflash_spi_ids,
937
938	/* FIXME:  investigate suspend and resume... */
939};
940
941module_spi_driver(dataflash_driver);
942
943MODULE_LICENSE("GPL");
944MODULE_AUTHOR("Andrew Victor, David Brownell");
945MODULE_DESCRIPTION("MTD DataFlash driver");
946MODULE_ALIAS("spi:mtd_dataflash");
947