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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> | |
1c5454ee | 8 | * Author: Ryan Mallon |
ec77e21b RM |
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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
d43c36dc | 24 | #include <linux/sched.h> |
ec77e21b RM |
25 | |
26 | #include <linux/mtd/mtd.h> | |
27 | #include <linux/mtd/partitions.h> | |
28 | ||
29 | #include <linux/spi/spi.h> | |
30 | #include <linux/spi/flash.h> | |
31 | ||
32 | /* Erases can take up to 3 seconds! */ | |
33 | #define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000) | |
34 | ||
35 | #define SST25L_CMD_WRSR 0x01 /* Write status register */ | |
36 | #define SST25L_CMD_WRDI 0x04 /* Write disable */ | |
37 | #define SST25L_CMD_RDSR 0x05 /* Read status register */ | |
38 | #define SST25L_CMD_WREN 0x06 /* Write enable */ | |
39 | #define SST25L_CMD_READ 0x03 /* High speed read */ | |
40 | ||
41 | #define SST25L_CMD_EWSR 0x50 /* Enable write status register */ | |
42 | #define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */ | |
43 | #define SST25L_CMD_READ_ID 0x90 /* Read device ID */ | |
44 | #define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */ | |
45 | ||
46 | #define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */ | |
47 | #define SST25L_STATUS_WREN (1 << 1) /* Write enabled */ | |
48 | #define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */ | |
49 | #define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */ | |
50 | ||
51 | struct sst25l_flash { | |
52 | struct spi_device *spi; | |
53 | struct mutex lock; | |
54 | struct mtd_info mtd; | |
ec77e21b RM |
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 | ||
61cc8276 | 67 | static struct flash_info __devinitdata sst25l_flash_info[] = { |
ec77e21b RM |
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 | { | |
0ffe0ce3 HS |
74 | struct spi_message m; |
75 | struct spi_transfer t; | |
76 | unsigned char cmd_resp[2]; | |
ec77e21b RM |
77 | int err; |
78 | ||
0ffe0ce3 HS |
79 | spi_message_init(&m); |
80 | memset(&t, 0, sizeof(struct spi_transfer)); | |
81 | ||
82 | cmd_resp[0] = SST25L_CMD_RDSR; | |
83 | cmd_resp[1] = 0xff; | |
84 | t.tx_buf = cmd_resp; | |
85 | t.rx_buf = cmd_resp; | |
86 | t.len = sizeof(cmd_resp); | |
87 | spi_message_add_tail(&t, &m); | |
88 | err = spi_sync(flash->spi, &m); | |
ec77e21b RM |
89 | if (err < 0) |
90 | return err; | |
91 | ||
0ffe0ce3 | 92 | *status = cmd_resp[1]; |
ec77e21b RM |
93 | return 0; |
94 | } | |
95 | ||
96 | static int sst25l_write_enable(struct sst25l_flash *flash, int enable) | |
97 | { | |
98 | unsigned char command[2]; | |
99 | int status, err; | |
100 | ||
101 | command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI; | |
102 | err = spi_write(flash->spi, command, 1); | |
103 | if (err) | |
104 | return err; | |
105 | ||
106 | command[0] = SST25L_CMD_EWSR; | |
107 | err = spi_write(flash->spi, command, 1); | |
108 | if (err) | |
109 | return err; | |
110 | ||
111 | command[0] = SST25L_CMD_WRSR; | |
112 | command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1; | |
113 | err = spi_write(flash->spi, command, 2); | |
114 | if (err) | |
115 | return err; | |
116 | ||
117 | if (enable) { | |
118 | err = sst25l_status(flash, &status); | |
119 | if (err) | |
120 | return err; | |
121 | if (!(status & SST25L_STATUS_WREN)) | |
122 | return -EROFS; | |
123 | } | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
128 | static int sst25l_wait_till_ready(struct sst25l_flash *flash) | |
129 | { | |
130 | unsigned long deadline; | |
131 | int status, err; | |
132 | ||
133 | deadline = jiffies + MAX_READY_WAIT_JIFFIES; | |
134 | do { | |
135 | err = sst25l_status(flash, &status); | |
136 | if (err) | |
137 | return err; | |
138 | if (!(status & SST25L_STATUS_BUSY)) | |
139 | return 0; | |
140 | ||
141 | cond_resched(); | |
142 | } while (!time_after_eq(jiffies, deadline)); | |
143 | ||
144 | return -ETIMEDOUT; | |
145 | } | |
146 | ||
147 | static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset) | |
148 | { | |
149 | unsigned char command[4]; | |
150 | int err; | |
151 | ||
152 | err = sst25l_write_enable(flash, 1); | |
153 | if (err) | |
154 | return err; | |
155 | ||
156 | command[0] = SST25L_CMD_SECTOR_ERASE; | |
157 | command[1] = offset >> 16; | |
158 | command[2] = offset >> 8; | |
159 | command[3] = offset; | |
160 | err = spi_write(flash->spi, command, 4); | |
161 | if (err) | |
162 | return err; | |
163 | ||
164 | err = sst25l_wait_till_ready(flash); | |
165 | if (err) | |
166 | return err; | |
167 | ||
168 | return sst25l_write_enable(flash, 0); | |
169 | } | |
170 | ||
171 | static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr) | |
172 | { | |
173 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
174 | uint32_t addr, end; | |
175 | int err; | |
176 | ||
177 | /* Sanity checks */ | |
178 | if (instr->addr + instr->len > flash->mtd.size) | |
179 | return -EINVAL; | |
180 | ||
181 | if ((uint32_t)instr->len % mtd->erasesize) | |
182 | return -EINVAL; | |
183 | ||
184 | if ((uint32_t)instr->addr % mtd->erasesize) | |
185 | return -EINVAL; | |
186 | ||
187 | addr = instr->addr; | |
188 | end = addr + instr->len; | |
189 | ||
190 | mutex_lock(&flash->lock); | |
191 | ||
192 | err = sst25l_wait_till_ready(flash); | |
2eaaa5ff JS |
193 | if (err) { |
194 | mutex_unlock(&flash->lock); | |
ec77e21b | 195 | return err; |
2eaaa5ff | 196 | } |
ec77e21b RM |
197 | |
198 | while (addr < end) { | |
199 | err = sst25l_erase_sector(flash, addr); | |
200 | if (err) { | |
201 | mutex_unlock(&flash->lock); | |
202 | instr->state = MTD_ERASE_FAILED; | |
203 | dev_err(&flash->spi->dev, "Erase failed\n"); | |
204 | return err; | |
205 | } | |
206 | ||
207 | addr += mtd->erasesize; | |
208 | } | |
209 | ||
210 | mutex_unlock(&flash->lock); | |
211 | ||
212 | instr->state = MTD_ERASE_DONE; | |
213 | mtd_erase_callback(instr); | |
214 | return 0; | |
215 | } | |
216 | ||
217 | static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len, | |
218 | size_t *retlen, unsigned char *buf) | |
219 | { | |
220 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
221 | struct spi_transfer transfer[2]; | |
222 | struct spi_message message; | |
223 | unsigned char command[4]; | |
224 | int ret; | |
225 | ||
226 | /* Sanity checking */ | |
227 | if (len == 0) | |
228 | return 0; | |
229 | ||
230 | if (from + len > flash->mtd.size) | |
231 | return -EINVAL; | |
232 | ||
233 | if (retlen) | |
234 | *retlen = 0; | |
235 | ||
236 | spi_message_init(&message); | |
237 | memset(&transfer, 0, sizeof(transfer)); | |
238 | ||
239 | command[0] = SST25L_CMD_READ; | |
240 | command[1] = from >> 16; | |
241 | command[2] = from >> 8; | |
242 | command[3] = from; | |
243 | ||
244 | transfer[0].tx_buf = command; | |
245 | transfer[0].len = sizeof(command); | |
246 | spi_message_add_tail(&transfer[0], &message); | |
247 | ||
248 | transfer[1].rx_buf = buf; | |
249 | transfer[1].len = len; | |
250 | spi_message_add_tail(&transfer[1], &message); | |
251 | ||
252 | mutex_lock(&flash->lock); | |
253 | ||
254 | /* Wait for previous write/erase to complete */ | |
255 | ret = sst25l_wait_till_ready(flash); | |
256 | if (ret) { | |
257 | mutex_unlock(&flash->lock); | |
258 | return ret; | |
259 | } | |
260 | ||
261 | spi_sync(flash->spi, &message); | |
262 | ||
263 | if (retlen && message.actual_length > sizeof(command)) | |
264 | *retlen += message.actual_length - sizeof(command); | |
265 | ||
266 | mutex_unlock(&flash->lock); | |
267 | return 0; | |
268 | } | |
269 | ||
270 | static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len, | |
271 | size_t *retlen, const unsigned char *buf) | |
272 | { | |
273 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
274 | int i, j, ret, bytes, copied = 0; | |
275 | unsigned char command[5]; | |
276 | ||
277 | /* Sanity checks */ | |
278 | if (!len) | |
279 | return 0; | |
280 | ||
281 | if (to + len > flash->mtd.size) | |
282 | return -EINVAL; | |
283 | ||
284 | if ((uint32_t)to % mtd->writesize) | |
285 | return -EINVAL; | |
286 | ||
287 | mutex_lock(&flash->lock); | |
288 | ||
289 | ret = sst25l_write_enable(flash, 1); | |
290 | if (ret) | |
291 | goto out; | |
292 | ||
293 | for (i = 0; i < len; i += mtd->writesize) { | |
294 | ret = sst25l_wait_till_ready(flash); | |
295 | if (ret) | |
296 | goto out; | |
297 | ||
298 | /* Write the first byte of the page */ | |
299 | command[0] = SST25L_CMD_AAI_PROGRAM; | |
300 | command[1] = (to + i) >> 16; | |
301 | command[2] = (to + i) >> 8; | |
302 | command[3] = (to + i); | |
303 | command[4] = buf[i]; | |
304 | ret = spi_write(flash->spi, command, 5); | |
305 | if (ret < 0) | |
306 | goto out; | |
307 | copied++; | |
308 | ||
309 | /* | |
310 | * Write the remaining bytes using auto address | |
311 | * increment mode | |
312 | */ | |
313 | bytes = min_t(uint32_t, mtd->writesize, len - i); | |
314 | for (j = 1; j < bytes; j++, copied++) { | |
315 | ret = sst25l_wait_till_ready(flash); | |
316 | if (ret) | |
317 | goto out; | |
318 | ||
319 | command[1] = buf[i + j]; | |
320 | ret = spi_write(flash->spi, command, 2); | |
321 | if (ret) | |
322 | goto out; | |
323 | } | |
324 | } | |
325 | ||
326 | out: | |
327 | ret = sst25l_write_enable(flash, 0); | |
328 | ||
329 | if (retlen) | |
330 | *retlen = copied; | |
331 | ||
332 | mutex_unlock(&flash->lock); | |
333 | return ret; | |
334 | } | |
335 | ||
6b2995b6 | 336 | static struct flash_info *__devinit sst25l_match_device(struct spi_device *spi) |
ec77e21b RM |
337 | { |
338 | struct flash_info *flash_info = NULL; | |
0ffe0ce3 HS |
339 | struct spi_message m; |
340 | struct spi_transfer t; | |
341 | unsigned char cmd_resp[6]; | |
ec77e21b RM |
342 | int i, err; |
343 | uint16_t id; | |
344 | ||
0ffe0ce3 HS |
345 | spi_message_init(&m); |
346 | memset(&t, 0, sizeof(struct spi_transfer)); | |
347 | ||
348 | cmd_resp[0] = SST25L_CMD_READ_ID; | |
349 | cmd_resp[1] = 0; | |
350 | cmd_resp[2] = 0; | |
351 | cmd_resp[3] = 0; | |
352 | cmd_resp[4] = 0xff; | |
353 | cmd_resp[5] = 0xff; | |
354 | t.tx_buf = cmd_resp; | |
355 | t.rx_buf = cmd_resp; | |
356 | t.len = sizeof(cmd_resp); | |
357 | spi_message_add_tail(&t, &m); | |
358 | err = spi_sync(spi, &m); | |
ec77e21b | 359 | if (err < 0) { |
0ffe0ce3 | 360 | dev_err(&spi->dev, "error reading device id\n"); |
ec77e21b RM |
361 | return NULL; |
362 | } | |
363 | ||
0ffe0ce3 | 364 | id = (cmd_resp[4] << 8) | cmd_resp[5]; |
ec77e21b RM |
365 | |
366 | for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++) | |
367 | if (sst25l_flash_info[i].device_id == id) | |
368 | flash_info = &sst25l_flash_info[i]; | |
369 | ||
370 | if (!flash_info) | |
371 | dev_err(&spi->dev, "unknown id %.4x\n", id); | |
372 | ||
373 | return flash_info; | |
374 | } | |
375 | ||
6b2995b6 | 376 | static int __devinit sst25l_probe(struct spi_device *spi) |
ec77e21b RM |
377 | { |
378 | struct flash_info *flash_info; | |
379 | struct sst25l_flash *flash; | |
380 | struct flash_platform_data *data; | |
d81a32f2 | 381 | int ret; |
ec77e21b RM |
382 | |
383 | flash_info = sst25l_match_device(spi); | |
384 | if (!flash_info) | |
385 | return -ENODEV; | |
386 | ||
387 | flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL); | |
388 | if (!flash) | |
389 | return -ENOMEM; | |
390 | ||
391 | flash->spi = spi; | |
392 | mutex_init(&flash->lock); | |
393 | dev_set_drvdata(&spi->dev, flash); | |
394 | ||
395 | data = spi->dev.platform_data; | |
396 | if (data && data->name) | |
397 | flash->mtd.name = data->name; | |
398 | else | |
399 | flash->mtd.name = dev_name(&spi->dev); | |
400 | ||
401 | flash->mtd.type = MTD_NORFLASH; | |
402 | flash->mtd.flags = MTD_CAP_NORFLASH; | |
403 | flash->mtd.erasesize = flash_info->erase_size; | |
404 | flash->mtd.writesize = flash_info->page_size; | |
405 | flash->mtd.size = flash_info->page_size * flash_info->nr_pages; | |
406 | flash->mtd.erase = sst25l_erase; | |
407 | flash->mtd.read = sst25l_read; | |
408 | flash->mtd.write = sst25l_write; | |
409 | ||
410 | dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name, | |
411 | (long long)flash->mtd.size >> 10); | |
412 | ||
289c0522 | 413 | pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) " |
ec77e21b RM |
414 | ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n", |
415 | flash->mtd.name, | |
416 | (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20), | |
417 | flash->mtd.erasesize, flash->mtd.erasesize / 1024, | |
418 | flash->mtd.numeraseregions); | |
419 | ||
ec77e21b | 420 | |
81939afc DES |
421 | ret = mtd_device_parse_register(&flash->mtd, NULL, 0, |
422 | data ? data->parts : NULL, | |
423 | data ? data->nr_parts : 0); | |
424 | if (ret) { | |
ec77e21b RM |
425 | kfree(flash); |
426 | dev_set_drvdata(&spi->dev, NULL); | |
427 | return -ENODEV; | |
428 | } | |
429 | ||
430 | return 0; | |
431 | } | |
432 | ||
61cc8276 | 433 | static int __devexit sst25l_remove(struct spi_device *spi) |
ec77e21b RM |
434 | { |
435 | struct sst25l_flash *flash = dev_get_drvdata(&spi->dev); | |
436 | int ret; | |
437 | ||
98b3979b | 438 | ret = mtd_device_unregister(&flash->mtd); |
ec77e21b RM |
439 | if (ret == 0) |
440 | kfree(flash); | |
441 | return ret; | |
442 | } | |
443 | ||
444 | static struct spi_driver sst25l_driver = { | |
445 | .driver = { | |
446 | .name = "sst25l", | |
ec77e21b RM |
447 | .owner = THIS_MODULE, |
448 | }, | |
449 | .probe = sst25l_probe, | |
61cc8276 | 450 | .remove = __devexit_p(sst25l_remove), |
ec77e21b RM |
451 | }; |
452 | ||
453 | static int __init sst25l_init(void) | |
454 | { | |
455 | return spi_register_driver(&sst25l_driver); | |
456 | } | |
457 | ||
458 | static void __exit sst25l_exit(void) | |
459 | { | |
460 | spi_unregister_driver(&sst25l_driver); | |
461 | } | |
462 | ||
463 | module_init(sst25l_init); | |
464 | module_exit(sst25l_exit); | |
465 | ||
466 | MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips"); | |
467 | MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, " | |
1c5454ee | 468 | "Ryan Mallon"); |
ec77e21b | 469 | MODULE_LICENSE("GPL"); |