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ec77e21b RM |
1 | /* |
2 | * sst25l.c | |
3 | * | |
4 | * Driver for SST25L SPI Flash chips | |
5 | * | |
6 | * Copyright © 2009 Bluewater Systems Ltd | |
7 | * Author: Andre Renaud <andre@bluewatersys.com> | |
8 | * Author: Ryan Mallon <ryan@bluewatersys.com> | |
9 | * | |
10 | * Based on m25p80.c | |
11 | * | |
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. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/init.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/device.h> | |
21 | #include <linux/mutex.h> | |
22 | #include <linux/interrupt.h> | |
23 | ||
24 | #include <linux/mtd/mtd.h> | |
25 | #include <linux/mtd/partitions.h> | |
26 | ||
27 | #include <linux/spi/spi.h> | |
28 | #include <linux/spi/flash.h> | |
29 | ||
30 | /* Erases can take up to 3 seconds! */ | |
31 | #define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000) | |
32 | ||
33 | #define SST25L_CMD_WRSR 0x01 /* Write status register */ | |
34 | #define SST25L_CMD_WRDI 0x04 /* Write disable */ | |
35 | #define SST25L_CMD_RDSR 0x05 /* Read status register */ | |
36 | #define SST25L_CMD_WREN 0x06 /* Write enable */ | |
37 | #define SST25L_CMD_READ 0x03 /* High speed read */ | |
38 | ||
39 | #define SST25L_CMD_EWSR 0x50 /* Enable write status register */ | |
40 | #define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */ | |
41 | #define SST25L_CMD_READ_ID 0x90 /* Read device ID */ | |
42 | #define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */ | |
43 | ||
44 | #define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */ | |
45 | #define SST25L_STATUS_WREN (1 << 1) /* Write enabled */ | |
46 | #define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */ | |
47 | #define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */ | |
48 | ||
49 | struct sst25l_flash { | |
50 | struct spi_device *spi; | |
51 | struct mutex lock; | |
52 | struct mtd_info mtd; | |
53 | ||
54 | int partitioned; | |
55 | }; | |
56 | ||
57 | struct flash_info { | |
58 | const char *name; | |
59 | uint16_t device_id; | |
60 | unsigned page_size; | |
61 | unsigned nr_pages; | |
62 | unsigned erase_size; | |
63 | }; | |
64 | ||
65 | #define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd) | |
66 | ||
67 | static struct flash_info __initdata sst25l_flash_info[] = { | |
68 | {"sst25lf020a", 0xbf43, 256, 1024, 4096}, | |
69 | {"sst25lf040a", 0xbf44, 256, 2048, 4096}, | |
70 | }; | |
71 | ||
72 | static int sst25l_status(struct sst25l_flash *flash, int *status) | |
73 | { | |
74 | unsigned char command, response; | |
75 | int err; | |
76 | ||
77 | command = SST25L_CMD_RDSR; | |
78 | err = spi_write_then_read(flash->spi, &command, 1, &response, 1); | |
79 | if (err < 0) | |
80 | return err; | |
81 | ||
82 | *status = response; | |
83 | return 0; | |
84 | } | |
85 | ||
86 | static int sst25l_write_enable(struct sst25l_flash *flash, int enable) | |
87 | { | |
88 | unsigned char command[2]; | |
89 | int status, err; | |
90 | ||
91 | command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI; | |
92 | err = spi_write(flash->spi, command, 1); | |
93 | if (err) | |
94 | return err; | |
95 | ||
96 | command[0] = SST25L_CMD_EWSR; | |
97 | err = spi_write(flash->spi, command, 1); | |
98 | if (err) | |
99 | return err; | |
100 | ||
101 | command[0] = SST25L_CMD_WRSR; | |
102 | command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1; | |
103 | err = spi_write(flash->spi, command, 2); | |
104 | if (err) | |
105 | return err; | |
106 | ||
107 | if (enable) { | |
108 | err = sst25l_status(flash, &status); | |
109 | if (err) | |
110 | return err; | |
111 | if (!(status & SST25L_STATUS_WREN)) | |
112 | return -EROFS; | |
113 | } | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static int sst25l_wait_till_ready(struct sst25l_flash *flash) | |
119 | { | |
120 | unsigned long deadline; | |
121 | int status, err; | |
122 | ||
123 | deadline = jiffies + MAX_READY_WAIT_JIFFIES; | |
124 | do { | |
125 | err = sst25l_status(flash, &status); | |
126 | if (err) | |
127 | return err; | |
128 | if (!(status & SST25L_STATUS_BUSY)) | |
129 | return 0; | |
130 | ||
131 | cond_resched(); | |
132 | } while (!time_after_eq(jiffies, deadline)); | |
133 | ||
134 | return -ETIMEDOUT; | |
135 | } | |
136 | ||
137 | static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset) | |
138 | { | |
139 | unsigned char command[4]; | |
140 | int err; | |
141 | ||
142 | err = sst25l_write_enable(flash, 1); | |
143 | if (err) | |
144 | return err; | |
145 | ||
146 | command[0] = SST25L_CMD_SECTOR_ERASE; | |
147 | command[1] = offset >> 16; | |
148 | command[2] = offset >> 8; | |
149 | command[3] = offset; | |
150 | err = spi_write(flash->spi, command, 4); | |
151 | if (err) | |
152 | return err; | |
153 | ||
154 | err = sst25l_wait_till_ready(flash); | |
155 | if (err) | |
156 | return err; | |
157 | ||
158 | return sst25l_write_enable(flash, 0); | |
159 | } | |
160 | ||
161 | static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr) | |
162 | { | |
163 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
164 | uint32_t addr, end; | |
165 | int err; | |
166 | ||
167 | /* Sanity checks */ | |
168 | if (instr->addr + instr->len > flash->mtd.size) | |
169 | return -EINVAL; | |
170 | ||
171 | if ((uint32_t)instr->len % mtd->erasesize) | |
172 | return -EINVAL; | |
173 | ||
174 | if ((uint32_t)instr->addr % mtd->erasesize) | |
175 | return -EINVAL; | |
176 | ||
177 | addr = instr->addr; | |
178 | end = addr + instr->len; | |
179 | ||
180 | mutex_lock(&flash->lock); | |
181 | ||
182 | err = sst25l_wait_till_ready(flash); | |
183 | if (err) | |
184 | return err; | |
185 | ||
186 | while (addr < end) { | |
187 | err = sst25l_erase_sector(flash, addr); | |
188 | if (err) { | |
189 | mutex_unlock(&flash->lock); | |
190 | instr->state = MTD_ERASE_FAILED; | |
191 | dev_err(&flash->spi->dev, "Erase failed\n"); | |
192 | return err; | |
193 | } | |
194 | ||
195 | addr += mtd->erasesize; | |
196 | } | |
197 | ||
198 | mutex_unlock(&flash->lock); | |
199 | ||
200 | instr->state = MTD_ERASE_DONE; | |
201 | mtd_erase_callback(instr); | |
202 | return 0; | |
203 | } | |
204 | ||
205 | static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len, | |
206 | size_t *retlen, unsigned char *buf) | |
207 | { | |
208 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
209 | struct spi_transfer transfer[2]; | |
210 | struct spi_message message; | |
211 | unsigned char command[4]; | |
212 | int ret; | |
213 | ||
214 | /* Sanity checking */ | |
215 | if (len == 0) | |
216 | return 0; | |
217 | ||
218 | if (from + len > flash->mtd.size) | |
219 | return -EINVAL; | |
220 | ||
221 | if (retlen) | |
222 | *retlen = 0; | |
223 | ||
224 | spi_message_init(&message); | |
225 | memset(&transfer, 0, sizeof(transfer)); | |
226 | ||
227 | command[0] = SST25L_CMD_READ; | |
228 | command[1] = from >> 16; | |
229 | command[2] = from >> 8; | |
230 | command[3] = from; | |
231 | ||
232 | transfer[0].tx_buf = command; | |
233 | transfer[0].len = sizeof(command); | |
234 | spi_message_add_tail(&transfer[0], &message); | |
235 | ||
236 | transfer[1].rx_buf = buf; | |
237 | transfer[1].len = len; | |
238 | spi_message_add_tail(&transfer[1], &message); | |
239 | ||
240 | mutex_lock(&flash->lock); | |
241 | ||
242 | /* Wait for previous write/erase to complete */ | |
243 | ret = sst25l_wait_till_ready(flash); | |
244 | if (ret) { | |
245 | mutex_unlock(&flash->lock); | |
246 | return ret; | |
247 | } | |
248 | ||
249 | spi_sync(flash->spi, &message); | |
250 | ||
251 | if (retlen && message.actual_length > sizeof(command)) | |
252 | *retlen += message.actual_length - sizeof(command); | |
253 | ||
254 | mutex_unlock(&flash->lock); | |
255 | return 0; | |
256 | } | |
257 | ||
258 | static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len, | |
259 | size_t *retlen, const unsigned char *buf) | |
260 | { | |
261 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
262 | int i, j, ret, bytes, copied = 0; | |
263 | unsigned char command[5]; | |
264 | ||
265 | /* Sanity checks */ | |
266 | if (!len) | |
267 | return 0; | |
268 | ||
269 | if (to + len > flash->mtd.size) | |
270 | return -EINVAL; | |
271 | ||
272 | if ((uint32_t)to % mtd->writesize) | |
273 | return -EINVAL; | |
274 | ||
275 | mutex_lock(&flash->lock); | |
276 | ||
277 | ret = sst25l_write_enable(flash, 1); | |
278 | if (ret) | |
279 | goto out; | |
280 | ||
281 | for (i = 0; i < len; i += mtd->writesize) { | |
282 | ret = sst25l_wait_till_ready(flash); | |
283 | if (ret) | |
284 | goto out; | |
285 | ||
286 | /* Write the first byte of the page */ | |
287 | command[0] = SST25L_CMD_AAI_PROGRAM; | |
288 | command[1] = (to + i) >> 16; | |
289 | command[2] = (to + i) >> 8; | |
290 | command[3] = (to + i); | |
291 | command[4] = buf[i]; | |
292 | ret = spi_write(flash->spi, command, 5); | |
293 | if (ret < 0) | |
294 | goto out; | |
295 | copied++; | |
296 | ||
297 | /* | |
298 | * Write the remaining bytes using auto address | |
299 | * increment mode | |
300 | */ | |
301 | bytes = min_t(uint32_t, mtd->writesize, len - i); | |
302 | for (j = 1; j < bytes; j++, copied++) { | |
303 | ret = sst25l_wait_till_ready(flash); | |
304 | if (ret) | |
305 | goto out; | |
306 | ||
307 | command[1] = buf[i + j]; | |
308 | ret = spi_write(flash->spi, command, 2); | |
309 | if (ret) | |
310 | goto out; | |
311 | } | |
312 | } | |
313 | ||
314 | out: | |
315 | ret = sst25l_write_enable(flash, 0); | |
316 | ||
317 | if (retlen) | |
318 | *retlen = copied; | |
319 | ||
320 | mutex_unlock(&flash->lock); | |
321 | return ret; | |
322 | } | |
323 | ||
324 | static struct flash_info *__init sst25l_match_device(struct spi_device *spi) | |
325 | { | |
326 | struct flash_info *flash_info = NULL; | |
327 | unsigned char command[4], response; | |
328 | int i, err; | |
329 | uint16_t id; | |
330 | ||
331 | command[0] = SST25L_CMD_READ_ID; | |
332 | command[1] = 0; | |
333 | command[2] = 0; | |
334 | command[3] = 0; | |
335 | err = spi_write_then_read(spi, command, sizeof(command), &response, 1); | |
336 | if (err < 0) { | |
337 | dev_err(&spi->dev, "error reading device id msb\n"); | |
338 | return NULL; | |
339 | } | |
340 | ||
341 | id = response << 8; | |
342 | ||
343 | command[0] = SST25L_CMD_READ_ID; | |
344 | command[1] = 0; | |
345 | command[2] = 0; | |
346 | command[3] = 1; | |
347 | err = spi_write_then_read(spi, command, sizeof(command), &response, 1); | |
348 | if (err < 0) { | |
349 | dev_err(&spi->dev, "error reading device id lsb\n"); | |
350 | return NULL; | |
351 | } | |
352 | ||
353 | id |= response; | |
354 | ||
355 | for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++) | |
356 | if (sst25l_flash_info[i].device_id == id) | |
357 | flash_info = &sst25l_flash_info[i]; | |
358 | ||
359 | if (!flash_info) | |
360 | dev_err(&spi->dev, "unknown id %.4x\n", id); | |
361 | ||
362 | return flash_info; | |
363 | } | |
364 | ||
365 | static int __init sst25l_probe(struct spi_device *spi) | |
366 | { | |
367 | struct flash_info *flash_info; | |
368 | struct sst25l_flash *flash; | |
369 | struct flash_platform_data *data; | |
370 | int ret, i; | |
371 | ||
372 | flash_info = sst25l_match_device(spi); | |
373 | if (!flash_info) | |
374 | return -ENODEV; | |
375 | ||
376 | flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL); | |
377 | if (!flash) | |
378 | return -ENOMEM; | |
379 | ||
380 | flash->spi = spi; | |
381 | mutex_init(&flash->lock); | |
382 | dev_set_drvdata(&spi->dev, flash); | |
383 | ||
384 | data = spi->dev.platform_data; | |
385 | if (data && data->name) | |
386 | flash->mtd.name = data->name; | |
387 | else | |
388 | flash->mtd.name = dev_name(&spi->dev); | |
389 | ||
390 | flash->mtd.type = MTD_NORFLASH; | |
391 | flash->mtd.flags = MTD_CAP_NORFLASH; | |
392 | flash->mtd.erasesize = flash_info->erase_size; | |
393 | flash->mtd.writesize = flash_info->page_size; | |
394 | flash->mtd.size = flash_info->page_size * flash_info->nr_pages; | |
395 | flash->mtd.erase = sst25l_erase; | |
396 | flash->mtd.read = sst25l_read; | |
397 | flash->mtd.write = sst25l_write; | |
398 | ||
399 | dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name, | |
400 | (long long)flash->mtd.size >> 10); | |
401 | ||
402 | DEBUG(MTD_DEBUG_LEVEL2, | |
403 | "mtd .name = %s, .size = 0x%llx (%lldMiB) " | |
404 | ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n", | |
405 | flash->mtd.name, | |
406 | (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20), | |
407 | flash->mtd.erasesize, flash->mtd.erasesize / 1024, | |
408 | flash->mtd.numeraseregions); | |
409 | ||
410 | if (flash->mtd.numeraseregions) | |
411 | for (i = 0; i < flash->mtd.numeraseregions; i++) | |
412 | DEBUG(MTD_DEBUG_LEVEL2, | |
413 | "mtd.eraseregions[%d] = { .offset = 0x%llx, " | |
414 | ".erasesize = 0x%.8x (%uKiB), " | |
415 | ".numblocks = %d }\n", | |
416 | i, (long long)flash->mtd.eraseregions[i].offset, | |
417 | flash->mtd.eraseregions[i].erasesize, | |
418 | flash->mtd.eraseregions[i].erasesize / 1024, | |
419 | flash->mtd.eraseregions[i].numblocks); | |
420 | ||
421 | if (mtd_has_partitions()) { | |
422 | struct mtd_partition *parts = NULL; | |
423 | int nr_parts = 0; | |
424 | ||
425 | if (mtd_has_cmdlinepart()) { | |
426 | static const char *part_probes[] = | |
427 | {"cmdlinepart", NULL}; | |
428 | ||
429 | nr_parts = parse_mtd_partitions(&flash->mtd, | |
430 | part_probes, | |
431 | &parts, 0); | |
432 | } | |
433 | ||
434 | if (nr_parts <= 0 && data && data->parts) { | |
435 | parts = data->parts; | |
436 | nr_parts = data->nr_parts; | |
437 | } | |
438 | ||
439 | if (nr_parts > 0) { | |
440 | for (i = 0; i < nr_parts; i++) { | |
441 | DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = " | |
442 | "{.name = %s, .offset = 0x%llx, " | |
443 | ".size = 0x%llx (%lldKiB) }\n", | |
444 | i, parts[i].name, | |
445 | (long long)parts[i].offset, | |
446 | (long long)parts[i].size, | |
447 | (long long)(parts[i].size >> 10)); | |
448 | } | |
449 | ||
450 | flash->partitioned = 1; | |
451 | return add_mtd_partitions(&flash->mtd, | |
452 | parts, nr_parts); | |
453 | } | |
454 | ||
455 | } else if (data->nr_parts) { | |
456 | dev_warn(&spi->dev, "ignoring %d default partitions on %s\n", | |
457 | data->nr_parts, data->name); | |
458 | } | |
459 | ||
460 | ret = add_mtd_device(&flash->mtd); | |
461 | if (ret == 1) { | |
462 | kfree(flash); | |
463 | dev_set_drvdata(&spi->dev, NULL); | |
464 | return -ENODEV; | |
465 | } | |
466 | ||
467 | return 0; | |
468 | } | |
469 | ||
470 | static int __exit sst25l_remove(struct spi_device *spi) | |
471 | { | |
472 | struct sst25l_flash *flash = dev_get_drvdata(&spi->dev); | |
473 | int ret; | |
474 | ||
475 | if (mtd_has_partitions() && flash->partitioned) | |
476 | ret = del_mtd_partitions(&flash->mtd); | |
477 | else | |
478 | ret = del_mtd_device(&flash->mtd); | |
479 | if (ret == 0) | |
480 | kfree(flash); | |
481 | return ret; | |
482 | } | |
483 | ||
484 | static struct spi_driver sst25l_driver = { | |
485 | .driver = { | |
486 | .name = "sst25l", | |
487 | .bus = &spi_bus_type, | |
488 | .owner = THIS_MODULE, | |
489 | }, | |
490 | .probe = sst25l_probe, | |
491 | .remove = __exit_p(sst25l_remove), | |
492 | }; | |
493 | ||
494 | static int __init sst25l_init(void) | |
495 | { | |
496 | return spi_register_driver(&sst25l_driver); | |
497 | } | |
498 | ||
499 | static void __exit sst25l_exit(void) | |
500 | { | |
501 | spi_unregister_driver(&sst25l_driver); | |
502 | } | |
503 | ||
504 | module_init(sst25l_init); | |
505 | module_exit(sst25l_exit); | |
506 | ||
507 | MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips"); | |
508 | MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, " | |
509 | "Ryan Mallon <ryan@bluewatersys.com>"); | |
510 | MODULE_LICENSE("GPL"); |