1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Atmel DataFlash probing
4  *
5  * Copyright (C) 2004-2009, 2015 Freescale Semiconductor, Inc.
6  * Haikun Wang (haikun.wang@freescale.com)
7  */
8 
9 #include <common.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <fdtdec.h>
13 #include <flash.h>
14 #include <log.h>
15 #include <spi.h>
16 #include <spi_flash.h>
17 #include <div64.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/math64.h>
21 
22 #include "sf_internal.h"
23 
24 #define CMD_READ_ID		0x9f
25 /* reads can bypass the buffers */
26 #define OP_READ_CONTINUOUS	0xE8
27 #define OP_READ_PAGE		0xD2
28 
29 /* group B requests can run even while status reports "busy" */
30 #define OP_READ_STATUS		0xD7	/* group B */
31 
32 /* move data between host and buffer */
33 #define OP_READ_BUFFER1		0xD4	/* group B */
34 #define OP_READ_BUFFER2		0xD6	/* group B */
35 #define OP_WRITE_BUFFER1	0x84	/* group B */
36 #define OP_WRITE_BUFFER2	0x87	/* group B */
37 
38 /* erasing flash */
39 #define OP_ERASE_PAGE		0x81
40 #define OP_ERASE_BLOCK		0x50
41 
42 /* move data between buffer and flash */
43 #define OP_TRANSFER_BUF1	0x53
44 #define OP_TRANSFER_BUF2	0x55
45 #define OP_MREAD_BUFFER1	0xD4
46 #define OP_MREAD_BUFFER2	0xD6
47 #define OP_MWERASE_BUFFER1	0x83
48 #define OP_MWERASE_BUFFER2	0x86
49 #define OP_MWRITE_BUFFER1	0x88	/* sector must be pre-erased */
50 #define OP_MWRITE_BUFFER2	0x89	/* sector must be pre-erased */
51 
52 /* write to buffer, then write-erase to flash */
53 #define OP_PROGRAM_VIA_BUF1	0x82
54 #define OP_PROGRAM_VIA_BUF2	0x85
55 
56 /* compare buffer to flash */
57 #define OP_COMPARE_BUF1		0x60
58 #define OP_COMPARE_BUF2		0x61
59 
60 /* read flash to buffer, then write-erase to flash */
61 #define OP_REWRITE_VIA_BUF1	0x58
62 #define OP_REWRITE_VIA_BUF2	0x59
63 
64 /*
65  * newer chips report JEDEC manufacturer and device IDs; chip
66  * serial number and OTP bits; and per-sector writeprotect.
67  */
68 #define OP_READ_ID		0x9F
69 #define OP_READ_SECURITY	0x77
70 #define OP_WRITE_SECURITY_REVC	0x9A
71 #define OP_WRITE_SECURITY	0x9B	/* revision D */
72 
73 struct dataflash {
74 	uint8_t			command[16];
75 	unsigned short		page_offset;	/* offset in flash address */
76 };
77 
78 /* Return the status of the DataFlash device */
dataflash_status(struct spi_slave * spi)79 static inline int dataflash_status(struct spi_slave *spi)
80 {
81 	int ret;
82 	u8 opcode = OP_READ_STATUS;
83 	u8 status;
84 
85 	/*
86 	 * NOTE:  at45db321c over 25 MHz wants to write
87 	 * a dummy byte after the opcode...
88 	 */
89 	ret =  spi_write_then_read(spi, &opcode, 1, NULL, &status, 1);
90 	return ret ? -EIO : status;
91 }
92 
93 /*
94  * Poll the DataFlash device until it is READY.
95  * This usually takes 5-20 msec or so; more for sector erase.
96  * ready: return > 0
97  */
dataflash_waitready(struct spi_slave * spi)98 static int dataflash_waitready(struct spi_slave *spi)
99 {
100 	int status;
101 	int timeout = 2 * CONFIG_SYS_HZ;
102 	int timebase;
103 
104 	timebase = get_timer(0);
105 	do {
106 		status = dataflash_status(spi);
107 		if (status < 0)
108 			status = 0;
109 
110 		if (status & (1 << 7))	/* RDY/nBSY */
111 			return status;
112 
113 		mdelay(3);
114 	} while (get_timer(timebase) < timeout);
115 
116 	return -ETIME;
117 }
118 
119 /* Erase pages of flash */
spi_dataflash_erase(struct udevice * dev,u32 offset,size_t len)120 static int spi_dataflash_erase(struct udevice *dev, u32 offset, size_t len)
121 {
122 	struct dataflash	*dataflash;
123 	struct spi_flash	*spi_flash;
124 	struct spi_slave	*spi;
125 	unsigned		blocksize;
126 	uint8_t			*command;
127 	uint32_t		rem;
128 	int			status;
129 
130 	dataflash = dev_get_priv(dev);
131 	spi_flash = dev_get_uclass_priv(dev);
132 	spi = spi_flash->spi;
133 
134 	blocksize = spi_flash->page_size << 3;
135 
136 	memset(dataflash->command, 0 , sizeof(dataflash->command));
137 	command = dataflash->command;
138 
139 	debug("%s: erase addr=0x%x len 0x%x\n", dev->name, offset, len);
140 
141 	div_u64_rem(len, spi_flash->page_size, &rem);
142 	if (rem) {
143 		printf("%s: len(0x%x) isn't the multiple of page size(0x%x)\n",
144 		       dev->name, len, spi_flash->page_size);
145 		return -EINVAL;
146 	}
147 	div_u64_rem(offset, spi_flash->page_size, &rem);
148 	if (rem) {
149 		printf("%s: offset(0x%x) isn't the multiple of page size(0x%x)\n",
150 		       dev->name, offset, spi_flash->page_size);
151 		return -EINVAL;
152 	}
153 
154 	status = spi_claim_bus(spi);
155 	if (status) {
156 		debug("dataflash: unable to claim SPI bus\n");
157 		return status;
158 	}
159 
160 	while (len > 0) {
161 		unsigned int	pageaddr;
162 		int		do_block;
163 		/*
164 		 * Calculate flash page address; use block erase (for speed) if
165 		 * we're at a block boundary and need to erase the whole block.
166 		 */
167 		pageaddr = div_u64(offset, spi_flash->page_size);
168 		do_block = (pageaddr & 0x7) == 0 && len >= blocksize;
169 		pageaddr = pageaddr << dataflash->page_offset;
170 
171 		command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE;
172 		command[1] = (uint8_t)(pageaddr >> 16);
173 		command[2] = (uint8_t)(pageaddr >> 8);
174 		command[3] = 0;
175 
176 		debug("%s ERASE %s: (%x) %x %x %x [%d]\n",
177 		      dev->name, do_block ? "block" : "page",
178 		      command[0], command[1], command[2], command[3],
179 		      pageaddr);
180 
181 		status = spi_write_then_read(spi, command, 4, NULL, NULL, 0);
182 		if (status < 0) {
183 			debug("%s: erase send command error!\n", dev->name);
184 			return -EIO;
185 		}
186 
187 		status = dataflash_waitready(spi);
188 		if (status < 0) {
189 			debug("%s: erase waitready error!\n", dev->name);
190 			return status;
191 		}
192 
193 		if (do_block) {
194 			offset += blocksize;
195 			len -= blocksize;
196 		} else {
197 			offset += spi_flash->page_size;
198 			len -= spi_flash->page_size;
199 		}
200 	}
201 
202 	spi_release_bus(spi);
203 
204 	return 0;
205 }
206 
207 /*
208  * Read from the DataFlash device.
209  *   offset : Start offset in flash device
210  *   len    : Amount to read
211  *   buf    : Buffer containing the data
212  */
spi_dataflash_read(struct udevice * dev,u32 offset,size_t len,void * buf)213 static int spi_dataflash_read(struct udevice *dev, u32 offset, size_t len,
214 			      void *buf)
215 {
216 	struct dataflash	*dataflash;
217 	struct spi_flash	*spi_flash;
218 	struct spi_slave	*spi;
219 	unsigned int		addr;
220 	uint8_t			*command;
221 	int			status;
222 
223 	dataflash = dev_get_priv(dev);
224 	spi_flash = dev_get_uclass_priv(dev);
225 	spi = spi_flash->spi;
226 
227 	memset(dataflash->command, 0 , sizeof(dataflash->command));
228 	command = dataflash->command;
229 
230 	debug("%s: erase addr=0x%x len 0x%x\n", dev->name, offset, len);
231 	debug("READ: (%x) %x %x %x\n",
232 	      command[0], command[1], command[2], command[3]);
233 
234 	/* Calculate flash page/byte address */
235 	addr = (((unsigned)offset / spi_flash->page_size)
236 	       << dataflash->page_offset)
237 	       + ((unsigned)offset % spi_flash->page_size);
238 
239 	status = spi_claim_bus(spi);
240 	if (status) {
241 		debug("dataflash: unable to claim SPI bus\n");
242 		return status;
243 	}
244 
245 	/*
246 	 * Continuous read, max clock = f(car) which may be less than
247 	 * the peak rate available.  Some chips support commands with
248 	 * fewer "don't care" bytes.  Both buffers stay unchanged.
249 	 */
250 	command[0] = OP_READ_CONTINUOUS;
251 	command[1] = (uint8_t)(addr >> 16);
252 	command[2] = (uint8_t)(addr >> 8);
253 	command[3] = (uint8_t)(addr >> 0);
254 
255 	/* plus 4 "don't care" bytes, command len: 4 + 4 "don't care" bytes */
256 	status = spi_write_then_read(spi, command, 8, NULL, buf, len);
257 
258 	spi_release_bus(spi);
259 
260 	return status;
261 }
262 
263 /*
264  * Write to the DataFlash device.
265  *   offset     : Start offset in flash device
266  *   len    : Amount to write
267  *   buf    : Buffer containing the data
268  */
spi_dataflash_write(struct udevice * dev,u32 offset,size_t len,const void * buf)269 int spi_dataflash_write(struct udevice *dev, u32 offset, size_t len,
270 			const void *buf)
271 {
272 	struct dataflash	*dataflash;
273 	struct spi_flash	*spi_flash;
274 	struct spi_slave	*spi;
275 	uint8_t			*command;
276 	unsigned int		pageaddr, addr, to, writelen;
277 	size_t			remaining = len;
278 	u_char			*writebuf = (u_char *)buf;
279 	int			status = -EINVAL;
280 
281 	dataflash = dev_get_priv(dev);
282 	spi_flash = dev_get_uclass_priv(dev);
283 	spi = spi_flash->spi;
284 
285 	memset(dataflash->command, 0 , sizeof(dataflash->command));
286 	command = dataflash->command;
287 
288 	debug("%s: write 0x%x..0x%x\n", dev->name, offset, (offset + len));
289 
290 	pageaddr = ((unsigned)offset / spi_flash->page_size);
291 	to = ((unsigned)offset % spi_flash->page_size);
292 	if (to + len > spi_flash->page_size)
293 		writelen = spi_flash->page_size - to;
294 	else
295 		writelen = len;
296 
297 	status = spi_claim_bus(spi);
298 	if (status) {
299 		debug("dataflash: unable to claim SPI bus\n");
300 		return status;
301 	}
302 
303 	while (remaining > 0) {
304 		debug("write @ %d:%d len=%d\n", pageaddr, to, writelen);
305 
306 		/*
307 		 * REVISIT:
308 		 * (a) each page in a sector must be rewritten at least
309 		 *     once every 10K sibling erase/program operations.
310 		 * (b) for pages that are already erased, we could
311 		 *     use WRITE+MWRITE not PROGRAM for ~30% speedup.
312 		 * (c) WRITE to buffer could be done while waiting for
313 		 *     a previous MWRITE/MWERASE to complete ...
314 		 * (d) error handling here seems to be mostly missing.
315 		 *
316 		 * Two persistent bits per page, plus a per-sector counter,
317 		 * could support (a) and (b) ... we might consider using
318 		 * the second half of sector zero, which is just one block,
319 		 * to track that state.  (On AT91, that sector should also
320 		 * support boot-from-DataFlash.)
321 		 */
322 
323 		addr = pageaddr << dataflash->page_offset;
324 
325 		/* (1) Maybe transfer partial page to Buffer1 */
326 		if (writelen != spi_flash->page_size) {
327 			command[0] = OP_TRANSFER_BUF1;
328 			command[1] = (addr & 0x00FF0000) >> 16;
329 			command[2] = (addr & 0x0000FF00) >> 8;
330 			command[3] = 0;
331 
332 			debug("TRANSFER: (%x) %x %x %x\n",
333 			      command[0], command[1], command[2], command[3]);
334 
335 			status = spi_write_then_read(spi, command, 4,
336 						     NULL, NULL, 0);
337 			if (status < 0) {
338 				debug("%s: write(<pagesize) command error!\n",
339 				      dev->name);
340 				return -EIO;
341 			}
342 
343 			status = dataflash_waitready(spi);
344 			if (status < 0) {
345 				debug("%s: write(<pagesize) waitready error!\n",
346 				      dev->name);
347 				return status;
348 			}
349 		}
350 
351 		/* (2) Program full page via Buffer1 */
352 		addr += to;
353 		command[0] = OP_PROGRAM_VIA_BUF1;
354 		command[1] = (addr & 0x00FF0000) >> 16;
355 		command[2] = (addr & 0x0000FF00) >> 8;
356 		command[3] = (addr & 0x000000FF);
357 
358 		debug("PROGRAM: (%x) %x %x %x\n",
359 		      command[0], command[1], command[2], command[3]);
360 
361 		status = spi_write_then_read(spi, command, 4,
362 					     writebuf, NULL, writelen);
363 		if (status < 0) {
364 			debug("%s: write send command error!\n", dev->name);
365 			return -EIO;
366 		}
367 
368 		status = dataflash_waitready(spi);
369 		if (status < 0) {
370 			debug("%s: write waitready error!\n", dev->name);
371 			return status;
372 		}
373 
374 #ifdef CONFIG_SPI_DATAFLASH_WRITE_VERIFY
375 		/* (3) Compare to Buffer1 */
376 		addr = pageaddr << dataflash->page_offset;
377 		command[0] = OP_COMPARE_BUF1;
378 		command[1] = (addr & 0x00FF0000) >> 16;
379 		command[2] = (addr & 0x0000FF00) >> 8;
380 		command[3] = 0;
381 
382 		debug("COMPARE: (%x) %x %x %x\n",
383 		      command[0], command[1], command[2], command[3]);
384 
385 		status = spi_write_then_read(spi, command, 4,
386 					     writebuf, NULL, writelen);
387 		if (status < 0) {
388 			debug("%s: write(compare) send command error!\n",
389 			      dev->name);
390 			return -EIO;
391 		}
392 
393 		status = dataflash_waitready(spi);
394 
395 		/* Check result of the compare operation */
396 		if (status & (1 << 6)) {
397 			printf("dataflash: write compare page %u, err %d\n",
398 			       pageaddr, status);
399 			remaining = 0;
400 			status = -EIO;
401 			break;
402 		} else {
403 			status = 0;
404 		}
405 
406 #endif	/* CONFIG_SPI_DATAFLASH_WRITE_VERIFY */
407 		remaining = remaining - writelen;
408 		pageaddr++;
409 		to = 0;
410 		writebuf += writelen;
411 
412 		if (remaining > spi_flash->page_size)
413 			writelen = spi_flash->page_size;
414 		else
415 			writelen = remaining;
416 	}
417 
418 	spi_release_bus(spi);
419 
420 	return 0;
421 }
422 
add_dataflash(struct udevice * dev,char * name,int nr_pages,int pagesize,int pageoffset,char revision)423 static int add_dataflash(struct udevice *dev, char *name, int nr_pages,
424 			     int pagesize, int pageoffset, char revision)
425 {
426 	struct spi_flash *spi_flash;
427 	struct dataflash *dataflash;
428 
429 	dataflash = dev_get_priv(dev);
430 	spi_flash = dev_get_uclass_priv(dev);
431 
432 	dataflash->page_offset = pageoffset;
433 
434 	spi_flash->name = name;
435 	spi_flash->page_size = pagesize;
436 	spi_flash->size = nr_pages * pagesize;
437 	spi_flash->erase_size = pagesize;
438 
439 #ifndef CONFIG_SPL_BUILD
440 	printf("SPI DataFlash: Detected %s with page size ", spi_flash->name);
441 	print_size(spi_flash->page_size, ", erase size ");
442 	print_size(spi_flash->erase_size, ", total ");
443 	print_size(spi_flash->size, "");
444 	printf(", revision %c", revision);
445 	puts("\n");
446 #endif
447 
448 	return 0;
449 }
450 
451 struct data_flash_info {
452 	char		*name;
453 
454 	/*
455 	 * JEDEC id has a high byte of zero plus three data bytes:
456 	 * the manufacturer id, then a two byte device id.
457 	 */
458 	uint32_t	jedec_id;
459 
460 	/* The size listed here is what works with OP_ERASE_PAGE. */
461 	unsigned	nr_pages;
462 	uint16_t	pagesize;
463 	uint16_t	pageoffset;
464 
465 	uint16_t	flags;
466 #define SUP_POW2PS	0x0002		/* supports 2^N byte pages */
467 #define IS_POW2PS	0x0001		/* uses 2^N byte pages */
468 };
469 
470 static struct data_flash_info dataflash_data[] = {
471 	/*
472 	 * NOTE:  chips with SUP_POW2PS (rev D and up) need two entries,
473 	 * one with IS_POW2PS and the other without.  The entry with the
474 	 * non-2^N byte page size can't name exact chip revisions without
475 	 * losing backwards compatibility for cmdlinepart.
476 	 *
477 	 * Those two entries have different name spelling format in order to
478 	 * show their difference obviously.
479 	 * The upper case refer to the chip isn't in normal 2^N bytes page-size
480 	 * mode.
481 	 * The lower case refer to the chip is in normal 2^N bytes page-size
482 	 * mode.
483 	 *
484 	 * These newer chips also support 128-byte security registers (with
485 	 * 64 bytes one-time-programmable) and software write-protection.
486 	 */
487 	{ "AT45DB011B",  0x1f2200, 512, 264, 9, SUP_POW2PS},
488 	{ "at45db011d",  0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS},
489 
490 	{ "AT45DB021B",  0x1f2300, 1024, 264, 9, SUP_POW2PS},
491 	{ "at45db021d",  0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS},
492 
493 	{ "AT45DB041x",  0x1f2400, 2048, 264, 9, SUP_POW2PS},
494 	{ "at45db041d",  0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS},
495 
496 	{ "AT45DB081B",  0x1f2500, 4096, 264, 9, SUP_POW2PS},
497 	{ "at45db081d",  0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS},
498 
499 	{ "AT45DB161x",  0x1f2600, 4096, 528, 10, SUP_POW2PS},
500 	{ "at45db161d",  0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS},
501 
502 	{ "AT45DB321x",  0x1f2700, 8192, 528, 10, 0},		/* rev C */
503 
504 	{ "AT45DB321x",  0x1f2701, 8192, 528, 10, SUP_POW2PS},
505 	{ "at45db321d",  0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS},
506 
507 	{ "AT45DB642x",  0x1f2800, 8192, 1056, 11, SUP_POW2PS},
508 	{ "at45db642d",  0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS},
509 };
510 
jedec_probe(struct spi_slave * spi)511 static struct data_flash_info *jedec_probe(struct spi_slave *spi)
512 {
513 	int			tmp;
514 	uint8_t			id[5];
515 	uint32_t		jedec;
516 	struct data_flash_info	*info;
517 	u8 opcode		= CMD_READ_ID;
518 	int status;
519 
520 	/*
521 	 * JEDEC also defines an optional "extended device information"
522 	 * string for after vendor-specific data, after the three bytes
523 	 * we use here.  Supporting some chips might require using it.
524 	 *
525 	 * If the vendor ID isn't Atmel's (0x1f), assume this call failed.
526 	 * That's not an error; only rev C and newer chips handle it, and
527 	 * only Atmel sells these chips.
528 	 */
529 	tmp = spi_write_then_read(spi, &opcode, 1, NULL, id, sizeof(id));
530 	if (tmp < 0) {
531 		printf("dataflash: error %d reading JEDEC ID\n", tmp);
532 		return ERR_PTR(tmp);
533 	}
534 	if (id[0] != 0x1f)
535 		return NULL;
536 
537 	jedec = id[0];
538 	jedec = jedec << 8;
539 	jedec |= id[1];
540 	jedec = jedec << 8;
541 	jedec |= id[2];
542 
543 	for (tmp = 0, info = dataflash_data;
544 			tmp < ARRAY_SIZE(dataflash_data);
545 			tmp++, info++) {
546 		if (info->jedec_id == jedec) {
547 			if (info->flags & SUP_POW2PS) {
548 				status = dataflash_status(spi);
549 				if (status < 0) {
550 					debug("dataflash: status error %d\n",
551 					      status);
552 					return NULL;
553 				}
554 				if (status & 0x1) {
555 					if (info->flags & IS_POW2PS)
556 						return info;
557 				} else {
558 					if (!(info->flags & IS_POW2PS))
559 						return info;
560 				}
561 			} else {
562 				return info;
563 			}
564 		}
565 	}
566 
567 	/*
568 	 * Treat other chips as errors ... we won't know the right page
569 	 * size (it might be binary) even when we can tell which density
570 	 * class is involved (legacy chip id scheme).
571 	 */
572 	printf("dataflash: JEDEC id %06x not handled\n", jedec);
573 	return ERR_PTR(-ENODEV);
574 }
575 
576 /*
577  * Detect and initialize DataFlash device, using JEDEC IDs on newer chips
578  * or else the ID code embedded in the status bits:
579  *
580  *   Device      Density         ID code          #Pages PageSize  Offset
581  *   AT45DB011B  1Mbit   (128K)  xx0011xx (0x0c)    512    264      9
582  *   AT45DB021B  2Mbit   (256K)  xx0101xx (0x14)   1024    264      9
583  *   AT45DB041B  4Mbit   (512K)  xx0111xx (0x1c)   2048    264      9
584  *   AT45DB081B  8Mbit   (1M)    xx1001xx (0x24)   4096    264      9
585  *   AT45DB0161B 16Mbit  (2M)    xx1011xx (0x2c)   4096    528     10
586  *   AT45DB0321B 32Mbit  (4M)    xx1101xx (0x34)   8192    528     10
587  *   AT45DB0642  64Mbit  (8M)    xx111xxx (0x3c)   8192   1056     11
588  *   AT45DB1282  128Mbit (16M)   xx0100xx (0x10)  16384   1056     11
589  */
spi_dataflash_probe(struct udevice * dev)590 static int spi_dataflash_probe(struct udevice *dev)
591 {
592 	struct spi_slave *spi = dev_get_parent_priv(dev);
593 	struct spi_flash *spi_flash;
594 	struct data_flash_info *info;
595 	int status;
596 
597 	spi_flash = dev_get_uclass_priv(dev);
598 	spi_flash->spi = spi;
599 	spi_flash->dev = dev;
600 
601 	status = spi_claim_bus(spi);
602 	if (status)
603 		return status;
604 
605 	/*
606 	 * Try to detect dataflash by JEDEC ID.
607 	 * If it succeeds we know we have either a C or D part.
608 	 * D will support power of 2 pagesize option.
609 	 * Both support the security register, though with different
610 	 * write procedures.
611 	 */
612 	info = jedec_probe(spi);
613 	if (IS_ERR(info))
614 		goto err_jedec_probe;
615 	if (info != NULL) {
616 		status = add_dataflash(dev, info->name, info->nr_pages,
617 				info->pagesize, info->pageoffset,
618 				(info->flags & SUP_POW2PS) ? 'd' : 'c');
619 		if (status < 0)
620 			goto err_status;
621 	}
622 
623        /*
624 	* Older chips support only legacy commands, identifing
625 	* capacity using bits in the status byte.
626 	*/
627 	status = dataflash_status(spi);
628 	if (status <= 0 || status == 0xff) {
629 		printf("dataflash: read status error %d\n", status);
630 		if (status == 0 || status == 0xff)
631 			status = -ENODEV;
632 		goto err_jedec_probe;
633 	}
634 
635        /*
636 	* if there's a device there, assume it's dataflash.
637 	* board setup should have set spi->max_speed_max to
638 	* match f(car) for continuous reads, mode 0 or 3.
639 	*/
640 	switch (status & 0x3c) {
641 	case 0x0c:	/* 0 0 1 1 x x */
642 		status = add_dataflash(dev, "AT45DB011B", 512, 264, 9, 0);
643 		break;
644 	case 0x14:	/* 0 1 0 1 x x */
645 		status = add_dataflash(dev, "AT45DB021B", 1024, 264, 9, 0);
646 		break;
647 	case 0x1c:	/* 0 1 1 1 x x */
648 		status = add_dataflash(dev, "AT45DB041x", 2048, 264, 9, 0);
649 		break;
650 	case 0x24:	/* 1 0 0 1 x x */
651 		status = add_dataflash(dev, "AT45DB081B", 4096, 264, 9, 0);
652 		break;
653 	case 0x2c:	/* 1 0 1 1 x x */
654 		status = add_dataflash(dev, "AT45DB161x", 4096, 528, 10, 0);
655 		break;
656 	case 0x34:	/* 1 1 0 1 x x */
657 		status = add_dataflash(dev, "AT45DB321x", 8192, 528, 10, 0);
658 		break;
659 	case 0x38:	/* 1 1 1 x x x */
660 	case 0x3c:
661 		status = add_dataflash(dev, "AT45DB642x", 8192, 1056, 11, 0);
662 		break;
663 	/* obsolete AT45DB1282 not (yet?) supported */
664 	default:
665 		printf("dataflash: unsupported device (%x)\n", status & 0x3c);
666 		status = -ENODEV;
667 		goto err_status;
668 	}
669 
670 	return status;
671 
672 err_status:
673 	spi_free_slave(spi);
674 err_jedec_probe:
675 	spi_release_bus(spi);
676 	return status;
677 }
678 
679 static const struct dm_spi_flash_ops spi_dataflash_ops = {
680 	.read = spi_dataflash_read,
681 	.write = spi_dataflash_write,
682 	.erase = spi_dataflash_erase,
683 };
684 
685 static const struct udevice_id spi_dataflash_ids[] = {
686 	{ .compatible = "atmel,at45", },
687 	{ .compatible = "atmel,dataflash", },
688 	{ }
689 };
690 
691 U_BOOT_DRIVER(spi_dataflash) = {
692 	.name		= "spi_dataflash",
693 	.id		= UCLASS_SPI_FLASH,
694 	.of_match	= spi_dataflash_ids,
695 	.probe		= spi_dataflash_probe,
696 	.priv_auto	= sizeof(struct dataflash),
697 	.ops		= &spi_dataflash_ops,
698 };
699