2 * MTD SPI driver for ST M25Pxx (and similar) serial flash chips
4 * Author: Mike Lavender, mike@steroidmicros.com
6 * Copyright (c) 2005, Intec Automation Inc.
8 * Some parts are based on lart.c by Abraham Van Der Merwe
10 * Cleaned up and generalized based on mtd_dataflash.c
12 * This code is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/interrupt.h>
22 #include <linux/mutex.h>
24 #include <linux/mtd/mtd.h>
25 #include <linux/mtd/partitions.h>
27 #include <linux/spi/spi.h>
28 #include <linux/spi/flash.h>
31 #define FLASH_PAGESIZE 256
34 #define OPCODE_WREN 0x06 /* Write enable */
35 #define OPCODE_RDSR 0x05 /* Read status register */
36 #define OPCODE_WRSR 0x01 /* Write status register 1 byte */
37 #define OPCODE_NORM_READ 0x03 /* Read data bytes (low frequency) */
38 #define OPCODE_FAST_READ 0x0b /* Read data bytes (high frequency) */
39 #define OPCODE_PP 0x02 /* Page program (up to 256 bytes) */
40 #define OPCODE_BE_4K 0x20 /* Erase 4KiB block */
41 #define OPCODE_BE_32K 0x52 /* Erase 32KiB block */
42 #define OPCODE_SE 0xd8 /* Sector erase (usually 64KiB) */
43 #define OPCODE_RDID 0x9f /* Read JEDEC ID */
45 /* Status Register bits. */
46 #define SR_WIP 1 /* Write in progress */
47 #define SR_WEL 2 /* Write enable latch */
48 /* meaning of other SR_* bits may differ between vendors */
49 #define SR_BP0 4 /* Block protect 0 */
50 #define SR_BP1 8 /* Block protect 1 */
51 #define SR_BP2 0x10 /* Block protect 2 */
52 #define SR_SRWD 0x80 /* SR write protect */
54 /* Define max times to check status register before we give up. */
55 #define MAX_READY_WAIT_COUNT 100000
58 #ifdef CONFIG_M25PXX_USE_FAST_READ
59 #define OPCODE_READ OPCODE_FAST_READ
60 #define FAST_READ_DUMMY_BYTE 1
62 #define OPCODE_READ OPCODE_NORM_READ
63 #define FAST_READ_DUMMY_BYTE 0
66 #ifdef CONFIG_MTD_PARTITIONS
67 #define mtd_has_partitions() (1)
69 #define mtd_has_partitions() (0)
72 /****************************************************************************/
75 struct spi_device *spi;
78 unsigned partitioned:1;
80 u8 command[CMD_SIZE + FAST_READ_DUMMY_BYTE];
83 static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
85 return container_of(mtd, struct m25p, mtd);
88 /****************************************************************************/
91 * Internal helper functions
95 * Read the status register, returning its value in the location
96 * Return the status register value.
97 * Returns negative if error occurred.
99 static int read_sr(struct m25p *flash)
102 u8 code = OPCODE_RDSR;
105 retval = spi_write_then_read(flash->spi, &code, 1, &val, 1);
108 dev_err(&flash->spi->dev, "error %d reading SR\n",
117 * Write status register 1 byte
118 * Returns negative if error occurred.
120 static int write_sr(struct m25p *flash, u8 val)
122 flash->command[0] = OPCODE_WRSR;
123 flash->command[1] = val;
125 return spi_write(flash->spi, flash->command, 2);
129 * Set write enable latch with Write Enable command.
130 * Returns negative if error occurred.
132 static inline int write_enable(struct m25p *flash)
134 u8 code = OPCODE_WREN;
136 return spi_write_then_read(flash->spi, &code, 1, NULL, 0);
141 * Service routine to read status register until ready, or timeout occurs.
142 * Returns non-zero if error.
144 static int wait_till_ready(struct m25p *flash)
149 /* one chip guarantees max 5 msec wait here after page writes,
150 * but potentially three seconds (!) after page erase.
152 for (count = 0; count < MAX_READY_WAIT_COUNT; count++) {
153 if ((sr = read_sr(flash)) < 0)
155 else if (!(sr & SR_WIP))
158 /* REVISIT sometimes sleeping would be best */
166 * Erase one sector of flash memory at offset ``offset'' which is any
167 * address within the sector which should be erased.
169 * Returns 0 if successful, non-zero otherwise.
171 static int erase_sector(struct m25p *flash, u32 offset)
173 DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB at 0x%08x\n",
174 flash->spi->dev.bus_id, __func__,
175 flash->mtd.erasesize / 1024, offset);
177 /* Wait until finished previous write command. */
178 if (wait_till_ready(flash))
181 /* Send write enable, then erase commands. */
184 /* Set up command buffer. */
185 flash->command[0] = flash->erase_opcode;
186 flash->command[1] = offset >> 16;
187 flash->command[2] = offset >> 8;
188 flash->command[3] = offset;
190 spi_write(flash->spi, flash->command, CMD_SIZE);
195 /****************************************************************************/
202 * Erase an address range on the flash chip. The address range may extend
203 * one or more erase sectors. Return an error is there is a problem erasing.
205 static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
207 struct m25p *flash = mtd_to_m25p(mtd);
210 DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %d\n",
211 flash->spi->dev.bus_id, __func__, "at",
212 (u32)instr->addr, instr->len);
215 if (instr->addr + instr->len > flash->mtd.size)
217 if ((instr->addr % mtd->erasesize) != 0
218 || (instr->len % mtd->erasesize) != 0) {
225 mutex_lock(&flash->lock);
227 /* REVISIT in some cases we could speed up erasing large regions
228 * by using OPCODE_SE instead of OPCODE_BE_4K
231 /* now erase those sectors */
233 if (erase_sector(flash, addr)) {
234 instr->state = MTD_ERASE_FAILED;
235 mutex_unlock(&flash->lock);
239 addr += mtd->erasesize;
240 len -= mtd->erasesize;
243 mutex_unlock(&flash->lock);
245 instr->state = MTD_ERASE_DONE;
246 mtd_erase_callback(instr);
252 * Read an address range from the flash chip. The address range
253 * may be any size provided it is within the physical boundaries.
255 static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
256 size_t *retlen, u_char *buf)
258 struct m25p *flash = mtd_to_m25p(mtd);
259 struct spi_transfer t[2];
260 struct spi_message m;
262 DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
263 flash->spi->dev.bus_id, __func__, "from",
270 if (from + len > flash->mtd.size)
273 spi_message_init(&m);
274 memset(t, 0, (sizeof t));
277 * OPCODE_FAST_READ (if available) is faster.
278 * Should add 1 byte DUMMY_BYTE.
280 t[0].tx_buf = flash->command;
281 t[0].len = CMD_SIZE + FAST_READ_DUMMY_BYTE;
282 spi_message_add_tail(&t[0], &m);
286 spi_message_add_tail(&t[1], &m);
288 /* Byte count starts at zero. */
292 mutex_lock(&flash->lock);
294 /* Wait till previous write/erase is done. */
295 if (wait_till_ready(flash)) {
296 /* REVISIT status return?? */
297 mutex_unlock(&flash->lock);
301 /* FIXME switch to OPCODE_FAST_READ. It's required for higher
302 * clocks; and at this writing, every chip this driver handles
303 * supports that opcode.
306 /* Set up the write data buffer. */
307 flash->command[0] = OPCODE_READ;
308 flash->command[1] = from >> 16;
309 flash->command[2] = from >> 8;
310 flash->command[3] = from;
312 spi_sync(flash->spi, &m);
314 *retlen = m.actual_length - CMD_SIZE - FAST_READ_DUMMY_BYTE;
316 mutex_unlock(&flash->lock);
322 * Write an address range to the flash chip. Data must be written in
323 * FLASH_PAGESIZE chunks. The address range may be any size provided
324 * it is within the physical boundaries.
326 static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
327 size_t *retlen, const u_char *buf)
329 struct m25p *flash = mtd_to_m25p(mtd);
330 u32 page_offset, page_size;
331 struct spi_transfer t[2];
332 struct spi_message m;
334 DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
335 flash->spi->dev.bus_id, __func__, "to",
345 if (to + len > flash->mtd.size)
348 spi_message_init(&m);
349 memset(t, 0, (sizeof t));
351 t[0].tx_buf = flash->command;
353 spi_message_add_tail(&t[0], &m);
356 spi_message_add_tail(&t[1], &m);
358 mutex_lock(&flash->lock);
360 /* Wait until finished previous write command. */
361 if (wait_till_ready(flash)) {
362 mutex_unlock(&flash->lock);
368 /* Set up the opcode in the write buffer. */
369 flash->command[0] = OPCODE_PP;
370 flash->command[1] = to >> 16;
371 flash->command[2] = to >> 8;
372 flash->command[3] = to;
374 /* what page do we start with? */
375 page_offset = to % FLASH_PAGESIZE;
377 /* do all the bytes fit onto one page? */
378 if (page_offset + len <= FLASH_PAGESIZE) {
381 spi_sync(flash->spi, &m);
383 *retlen = m.actual_length - CMD_SIZE;
387 /* the size of data remaining on the first page */
388 page_size = FLASH_PAGESIZE - page_offset;
390 t[1].len = page_size;
391 spi_sync(flash->spi, &m);
393 *retlen = m.actual_length - CMD_SIZE;
395 /* write everything in PAGESIZE chunks */
396 for (i = page_size; i < len; i += page_size) {
398 if (page_size > FLASH_PAGESIZE)
399 page_size = FLASH_PAGESIZE;
401 /* write the next page to flash */
402 flash->command[1] = (to + i) >> 16;
403 flash->command[2] = (to + i) >> 8;
404 flash->command[3] = (to + i);
406 t[1].tx_buf = buf + i;
407 t[1].len = page_size;
409 wait_till_ready(flash);
413 spi_sync(flash->spi, &m);
416 *retlen += m.actual_length - CMD_SIZE;
420 mutex_unlock(&flash->lock);
426 /****************************************************************************/
429 * SPI device driver setup and teardown
435 /* JEDEC id zero means "no ID" (most older chips); otherwise it has
436 * a high byte of zero plus three data bytes: the manufacturer id,
437 * then a two byte device id.
441 /* The size listed here is what works with OPCODE_SE, which isn't
442 * necessarily called a "sector" by the vendor.
444 unsigned sector_size;
448 #define SECT_4K 0x01 /* OPCODE_BE_4K works uniformly */
452 /* NOTE: double check command sets and memory organization when you add
453 * more flash chips. This current list focusses on newer chips, which
454 * have been converging on command sets which including JEDEC ID.
456 static struct flash_info __devinitdata m25p_data [] = {
458 /* Atmel -- some are (confusingly) marketed as "DataFlash" */
459 { "at25fs010", 0x1f6601, 32 * 1024, 4, SECT_4K, },
460 { "at25fs040", 0x1f6604, 64 * 1024, 8, SECT_4K, },
462 { "at25df041a", 0x1f4401, 64 * 1024, 8, SECT_4K, },
463 { "at25df641", 0x1f4800, 64 * 1024, 128, SECT_4K, },
465 { "at26f004", 0x1f0400, 64 * 1024, 8, SECT_4K, },
466 { "at26df081a", 0x1f4501, 64 * 1024, 16, SECT_4K, },
467 { "at26df161a", 0x1f4601, 64 * 1024, 32, SECT_4K, },
468 { "at26df321", 0x1f4701, 64 * 1024, 64, SECT_4K, },
470 /* Spansion -- single (large) sector size only, at least
471 * for the chips listed here (without boot sectors).
473 { "s25sl004a", 0x010212, 64 * 1024, 8, },
474 { "s25sl008a", 0x010213, 64 * 1024, 16, },
475 { "s25sl016a", 0x010214, 64 * 1024, 32, },
476 { "s25sl032a", 0x010215, 64 * 1024, 64, },
477 { "s25sl064a", 0x010216, 64 * 1024, 128, },
479 /* SST -- large erase sizes are "overlays", "sectors" are 4K */
480 { "sst25vf040b", 0xbf258d, 64 * 1024, 8, SECT_4K, },
481 { "sst25vf080b", 0xbf258e, 64 * 1024, 16, SECT_4K, },
482 { "sst25vf016b", 0xbf2541, 64 * 1024, 32, SECT_4K, },
483 { "sst25vf032b", 0xbf254a, 64 * 1024, 64, SECT_4K, },
485 /* ST Microelectronics -- newer production may have feature updates */
486 { "m25p05", 0x202010, 32 * 1024, 2, },
487 { "m25p10", 0x202011, 32 * 1024, 4, },
488 { "m25p20", 0x202012, 64 * 1024, 4, },
489 { "m25p40", 0x202013, 64 * 1024, 8, },
490 { "m25p80", 0, 64 * 1024, 16, },
491 { "m25p16", 0x202015, 64 * 1024, 32, },
492 { "m25p32", 0x202016, 64 * 1024, 64, },
493 { "m25p64", 0x202017, 64 * 1024, 128, },
494 { "m25p128", 0x202018, 256 * 1024, 64, },
496 { "m45pe80", 0x204014, 64 * 1024, 16, },
497 { "m45pe16", 0x204015, 64 * 1024, 32, },
499 { "m25pe80", 0x208014, 64 * 1024, 16, },
500 { "m25pe16", 0x208015, 64 * 1024, 32, SECT_4K, },
502 /* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
503 { "w25x10", 0xef3011, 64 * 1024, 2, SECT_4K, },
504 { "w25x20", 0xef3012, 64 * 1024, 4, SECT_4K, },
505 { "w25x40", 0xef3013, 64 * 1024, 8, SECT_4K, },
506 { "w25x80", 0xef3014, 64 * 1024, 16, SECT_4K, },
507 { "w25x16", 0xef3015, 64 * 1024, 32, SECT_4K, },
508 { "w25x32", 0xef3016, 64 * 1024, 64, SECT_4K, },
509 { "w25x64", 0xef3017, 64 * 1024, 128, SECT_4K, },
512 static struct flash_info *__devinit jedec_probe(struct spi_device *spi)
515 u8 code = OPCODE_RDID;
518 struct flash_info *info;
520 /* JEDEC also defines an optional "extended device information"
521 * string for after vendor-specific data, after the three bytes
522 * we use here. Supporting some chips might require using it.
524 tmp = spi_write_then_read(spi, &code, 1, id, 3);
526 DEBUG(MTD_DEBUG_LEVEL0, "%s: error %d reading JEDEC ID\n",
527 spi->dev.bus_id, tmp);
536 for (tmp = 0, info = m25p_data;
537 tmp < ARRAY_SIZE(m25p_data);
539 if (info->jedec_id == jedec)
542 dev_err(&spi->dev, "unrecognized JEDEC id %06x\n", jedec);
548 * board specific setup should have ensured the SPI clock used here
549 * matches what the READ command supports, at least until this driver
550 * understands FAST_READ (for clocks over 25 MHz).
552 static int __devinit m25p_probe(struct spi_device *spi)
554 struct flash_platform_data *data;
556 struct flash_info *info;
559 /* Platform data helps sort out which chip type we have, as
560 * well as how this board partitions it. If we don't have
561 * a chip ID, try the JEDEC id commands; they'll work for most
562 * newer chips, even if we don't recognize the particular chip.
564 data = spi->dev.platform_data;
565 if (data && data->type) {
566 for (i = 0, info = m25p_data;
567 i < ARRAY_SIZE(m25p_data);
569 if (strcmp(data->type, info->name) == 0)
573 /* unrecognized chip? */
574 if (i == ARRAY_SIZE(m25p_data)) {
575 DEBUG(MTD_DEBUG_LEVEL0, "%s: unrecognized id %s\n",
576 spi->dev.bus_id, data->type);
579 /* recognized; is that chip really what's there? */
580 } else if (info->jedec_id) {
581 struct flash_info *chip = jedec_probe(spi);
583 if (!chip || chip != info) {
584 dev_warn(&spi->dev, "found %s, expected %s\n",
585 chip ? chip->name : "UNKNOWN",
591 info = jedec_probe(spi);
596 flash = kzalloc(sizeof *flash, GFP_KERNEL);
601 mutex_init(&flash->lock);
602 dev_set_drvdata(&spi->dev, flash);
605 * Atmel serial flash tend to power up
606 * with the software protection bits set
609 if (info->jedec_id >> 16 == 0x1f) {
614 if (data && data->name)
615 flash->mtd.name = data->name;
617 flash->mtd.name = spi->dev.bus_id;
619 flash->mtd.type = MTD_NORFLASH;
620 flash->mtd.writesize = 1;
621 flash->mtd.flags = MTD_CAP_NORFLASH;
622 flash->mtd.size = info->sector_size * info->n_sectors;
623 flash->mtd.erase = m25p80_erase;
624 flash->mtd.read = m25p80_read;
625 flash->mtd.write = m25p80_write;
627 /* prefer "small sector" erase if possible */
628 if (info->flags & SECT_4K) {
629 flash->erase_opcode = OPCODE_BE_4K;
630 flash->mtd.erasesize = 4096;
632 flash->erase_opcode = OPCODE_SE;
633 flash->mtd.erasesize = info->sector_size;
636 dev_info(&spi->dev, "%s (%d Kbytes)\n", info->name,
637 flash->mtd.size / 1024);
639 DEBUG(MTD_DEBUG_LEVEL2,
640 "mtd .name = %s, .size = 0x%.8x (%uMiB) "
641 ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
643 flash->mtd.size, flash->mtd.size / (1024*1024),
644 flash->mtd.erasesize, flash->mtd.erasesize / 1024,
645 flash->mtd.numeraseregions);
647 if (flash->mtd.numeraseregions)
648 for (i = 0; i < flash->mtd.numeraseregions; i++)
649 DEBUG(MTD_DEBUG_LEVEL2,
650 "mtd.eraseregions[%d] = { .offset = 0x%.8x, "
651 ".erasesize = 0x%.8x (%uKiB), "
652 ".numblocks = %d }\n",
653 i, flash->mtd.eraseregions[i].offset,
654 flash->mtd.eraseregions[i].erasesize,
655 flash->mtd.eraseregions[i].erasesize / 1024,
656 flash->mtd.eraseregions[i].numblocks);
659 /* partitions should match sector boundaries; and it may be good to
660 * use readonly partitions for writeprotected sectors (BP2..BP0).
662 if (mtd_has_partitions()) {
663 struct mtd_partition *parts = NULL;
666 #ifdef CONFIG_MTD_CMDLINE_PARTS
667 static const char *part_probes[] = { "cmdlinepart", NULL, };
669 nr_parts = parse_mtd_partitions(&flash->mtd,
670 part_probes, &parts, 0);
673 if (nr_parts <= 0 && data && data->parts) {
675 nr_parts = data->nr_parts;
679 for (i = 0; i < nr_parts; i++) {
680 DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
681 "{.name = %s, .offset = 0x%.8x, "
682 ".size = 0x%.8x (%uKiB) }\n",
686 parts[i].size / 1024);
688 flash->partitioned = 1;
689 return add_mtd_partitions(&flash->mtd, parts, nr_parts);
691 } else if (data->nr_parts)
692 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
693 data->nr_parts, data->name);
695 return add_mtd_device(&flash->mtd) == 1 ? -ENODEV : 0;
699 static int __devexit m25p_remove(struct spi_device *spi)
701 struct m25p *flash = dev_get_drvdata(&spi->dev);
704 /* Clean up MTD stuff. */
705 if (mtd_has_partitions() && flash->partitioned)
706 status = del_mtd_partitions(&flash->mtd);
708 status = del_mtd_device(&flash->mtd);
715 static struct spi_driver m25p80_driver = {
718 .bus = &spi_bus_type,
719 .owner = THIS_MODULE,
722 .remove = __devexit_p(m25p_remove),
724 /* REVISIT: many of these chips have deep power-down modes, which
725 * should clearly be entered on suspend() to minimize power use.
726 * And also when they're otherwise idle...
731 static int m25p80_init(void)
733 return spi_register_driver(&m25p80_driver);
737 static void m25p80_exit(void)
739 spi_unregister_driver(&m25p80_driver);
743 module_init(m25p80_init);
744 module_exit(m25p80_exit);
746 MODULE_LICENSE("GPL");
747 MODULE_AUTHOR("Mike Lavender");
748 MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");