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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 | ||
ec77e21b RM |
18 | #include <linux/module.h> |
19 | #include <linux/device.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/interrupt.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
d43c36dc | 23 | #include <linux/sched.h> |
ec77e21b RM |
24 | |
25 | #include <linux/mtd/mtd.h> | |
26 | #include <linux/mtd/partitions.h> | |
27 | ||
28 | #include <linux/spi/spi.h> | |
29 | #include <linux/spi/flash.h> | |
30 | ||
31 | /* Erases can take up to 3 seconds! */ | |
32 | #define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000) | |
33 | ||
34 | #define SST25L_CMD_WRSR 0x01 /* Write status register */ | |
35 | #define SST25L_CMD_WRDI 0x04 /* Write disable */ | |
36 | #define SST25L_CMD_RDSR 0x05 /* Read status register */ | |
37 | #define SST25L_CMD_WREN 0x06 /* Write enable */ | |
38 | #define SST25L_CMD_READ 0x03 /* High speed read */ | |
39 | ||
40 | #define SST25L_CMD_EWSR 0x50 /* Enable write status register */ | |
41 | #define SST25L_CMD_SECTOR_ERASE 0x20 /* Erase sector */ | |
42 | #define SST25L_CMD_READ_ID 0x90 /* Read device ID */ | |
43 | #define SST25L_CMD_AAI_PROGRAM 0xaf /* Auto address increment */ | |
44 | ||
45 | #define SST25L_STATUS_BUSY (1 << 0) /* Chip is busy */ | |
46 | #define SST25L_STATUS_WREN (1 << 1) /* Write enabled */ | |
47 | #define SST25L_STATUS_BP0 (1 << 2) /* Block protection 0 */ | |
48 | #define SST25L_STATUS_BP1 (1 << 3) /* Block protection 1 */ | |
49 | ||
50 | struct sst25l_flash { | |
51 | struct spi_device *spi; | |
52 | struct mutex lock; | |
53 | struct mtd_info mtd; | |
ec77e21b RM |
54 | }; |
55 | ||
56 | struct flash_info { | |
57 | const char *name; | |
58 | uint16_t device_id; | |
59 | unsigned page_size; | |
60 | unsigned nr_pages; | |
61 | unsigned erase_size; | |
62 | }; | |
63 | ||
64 | #define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd) | |
65 | ||
042a1909 | 66 | static struct flash_info sst25l_flash_info[] = { |
ec77e21b RM |
67 | {"sst25lf020a", 0xbf43, 256, 1024, 4096}, |
68 | {"sst25lf040a", 0xbf44, 256, 2048, 4096}, | |
69 | }; | |
70 | ||
71 | static int sst25l_status(struct sst25l_flash *flash, int *status) | |
72 | { | |
0ffe0ce3 HS |
73 | struct spi_message m; |
74 | struct spi_transfer t; | |
75 | unsigned char cmd_resp[2]; | |
ec77e21b RM |
76 | int err; |
77 | ||
0ffe0ce3 HS |
78 | spi_message_init(&m); |
79 | memset(&t, 0, sizeof(struct spi_transfer)); | |
80 | ||
81 | cmd_resp[0] = SST25L_CMD_RDSR; | |
82 | cmd_resp[1] = 0xff; | |
83 | t.tx_buf = cmd_resp; | |
84 | t.rx_buf = cmd_resp; | |
85 | t.len = sizeof(cmd_resp); | |
86 | spi_message_add_tail(&t, &m); | |
87 | err = spi_sync(flash->spi, &m); | |
ec77e21b RM |
88 | if (err < 0) |
89 | return err; | |
90 | ||
0ffe0ce3 | 91 | *status = cmd_resp[1]; |
ec77e21b RM |
92 | return 0; |
93 | } | |
94 | ||
95 | static int sst25l_write_enable(struct sst25l_flash *flash, int enable) | |
96 | { | |
97 | unsigned char command[2]; | |
98 | int status, err; | |
99 | ||
100 | command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI; | |
101 | err = spi_write(flash->spi, command, 1); | |
102 | if (err) | |
103 | return err; | |
104 | ||
105 | command[0] = SST25L_CMD_EWSR; | |
106 | err = spi_write(flash->spi, command, 1); | |
107 | if (err) | |
108 | return err; | |
109 | ||
110 | command[0] = SST25L_CMD_WRSR; | |
111 | command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1; | |
112 | err = spi_write(flash->spi, command, 2); | |
113 | if (err) | |
114 | return err; | |
115 | ||
116 | if (enable) { | |
117 | err = sst25l_status(flash, &status); | |
118 | if (err) | |
119 | return err; | |
120 | if (!(status & SST25L_STATUS_WREN)) | |
121 | return -EROFS; | |
122 | } | |
123 | ||
124 | return 0; | |
125 | } | |
126 | ||
127 | static int sst25l_wait_till_ready(struct sst25l_flash *flash) | |
128 | { | |
129 | unsigned long deadline; | |
130 | int status, err; | |
131 | ||
132 | deadline = jiffies + MAX_READY_WAIT_JIFFIES; | |
133 | do { | |
134 | err = sst25l_status(flash, &status); | |
135 | if (err) | |
136 | return err; | |
137 | if (!(status & SST25L_STATUS_BUSY)) | |
138 | return 0; | |
139 | ||
140 | cond_resched(); | |
141 | } while (!time_after_eq(jiffies, deadline)); | |
142 | ||
143 | return -ETIMEDOUT; | |
144 | } | |
145 | ||
146 | static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset) | |
147 | { | |
148 | unsigned char command[4]; | |
149 | int err; | |
150 | ||
151 | err = sst25l_write_enable(flash, 1); | |
152 | if (err) | |
153 | return err; | |
154 | ||
155 | command[0] = SST25L_CMD_SECTOR_ERASE; | |
156 | command[1] = offset >> 16; | |
157 | command[2] = offset >> 8; | |
158 | command[3] = offset; | |
159 | err = spi_write(flash->spi, command, 4); | |
160 | if (err) | |
161 | return err; | |
162 | ||
163 | err = sst25l_wait_till_ready(flash); | |
164 | if (err) | |
165 | return err; | |
166 | ||
167 | return sst25l_write_enable(flash, 0); | |
168 | } | |
169 | ||
170 | static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr) | |
171 | { | |
172 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
173 | uint32_t addr, end; | |
174 | int err; | |
175 | ||
176 | /* Sanity checks */ | |
ec77e21b RM |
177 | if ((uint32_t)instr->len % mtd->erasesize) |
178 | return -EINVAL; | |
179 | ||
180 | if ((uint32_t)instr->addr % mtd->erasesize) | |
181 | return -EINVAL; | |
182 | ||
183 | addr = instr->addr; | |
184 | end = addr + instr->len; | |
185 | ||
186 | mutex_lock(&flash->lock); | |
187 | ||
188 | err = sst25l_wait_till_ready(flash); | |
2eaaa5ff JS |
189 | if (err) { |
190 | mutex_unlock(&flash->lock); | |
ec77e21b | 191 | return err; |
2eaaa5ff | 192 | } |
ec77e21b RM |
193 | |
194 | while (addr < end) { | |
195 | err = sst25l_erase_sector(flash, addr); | |
196 | if (err) { | |
197 | mutex_unlock(&flash->lock); | |
ec77e21b RM |
198 | dev_err(&flash->spi->dev, "Erase failed\n"); |
199 | return err; | |
200 | } | |
201 | ||
202 | addr += mtd->erasesize; | |
203 | } | |
204 | ||
205 | mutex_unlock(&flash->lock); | |
206 | ||
ec77e21b RM |
207 | return 0; |
208 | } | |
209 | ||
210 | static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len, | |
211 | size_t *retlen, unsigned char *buf) | |
212 | { | |
213 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
214 | struct spi_transfer transfer[2]; | |
215 | struct spi_message message; | |
216 | unsigned char command[4]; | |
217 | int ret; | |
218 | ||
ec77e21b RM |
219 | spi_message_init(&message); |
220 | memset(&transfer, 0, sizeof(transfer)); | |
221 | ||
222 | command[0] = SST25L_CMD_READ; | |
223 | command[1] = from >> 16; | |
224 | command[2] = from >> 8; | |
225 | command[3] = from; | |
226 | ||
227 | transfer[0].tx_buf = command; | |
228 | transfer[0].len = sizeof(command); | |
229 | spi_message_add_tail(&transfer[0], &message); | |
230 | ||
231 | transfer[1].rx_buf = buf; | |
232 | transfer[1].len = len; | |
233 | spi_message_add_tail(&transfer[1], &message); | |
234 | ||
235 | mutex_lock(&flash->lock); | |
236 | ||
237 | /* Wait for previous write/erase to complete */ | |
238 | ret = sst25l_wait_till_ready(flash); | |
239 | if (ret) { | |
240 | mutex_unlock(&flash->lock); | |
241 | return ret; | |
242 | } | |
243 | ||
244 | spi_sync(flash->spi, &message); | |
245 | ||
246 | if (retlen && message.actual_length > sizeof(command)) | |
247 | *retlen += message.actual_length - sizeof(command); | |
248 | ||
249 | mutex_unlock(&flash->lock); | |
250 | return 0; | |
251 | } | |
252 | ||
253 | static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len, | |
254 | size_t *retlen, const unsigned char *buf) | |
255 | { | |
256 | struct sst25l_flash *flash = to_sst25l_flash(mtd); | |
257 | int i, j, ret, bytes, copied = 0; | |
258 | unsigned char command[5]; | |
259 | ||
ec77e21b RM |
260 | if ((uint32_t)to % mtd->writesize) |
261 | return -EINVAL; | |
262 | ||
263 | mutex_lock(&flash->lock); | |
264 | ||
265 | ret = sst25l_write_enable(flash, 1); | |
266 | if (ret) | |
267 | goto out; | |
268 | ||
269 | for (i = 0; i < len; i += mtd->writesize) { | |
270 | ret = sst25l_wait_till_ready(flash); | |
271 | if (ret) | |
272 | goto out; | |
273 | ||
274 | /* Write the first byte of the page */ | |
275 | command[0] = SST25L_CMD_AAI_PROGRAM; | |
276 | command[1] = (to + i) >> 16; | |
277 | command[2] = (to + i) >> 8; | |
278 | command[3] = (to + i); | |
279 | command[4] = buf[i]; | |
280 | ret = spi_write(flash->spi, command, 5); | |
281 | if (ret < 0) | |
282 | goto out; | |
283 | copied++; | |
284 | ||
285 | /* | |
286 | * Write the remaining bytes using auto address | |
287 | * increment mode | |
288 | */ | |
289 | bytes = min_t(uint32_t, mtd->writesize, len - i); | |
290 | for (j = 1; j < bytes; j++, copied++) { | |
291 | ret = sst25l_wait_till_ready(flash); | |
292 | if (ret) | |
293 | goto out; | |
294 | ||
295 | command[1] = buf[i + j]; | |
296 | ret = spi_write(flash->spi, command, 2); | |
297 | if (ret) | |
298 | goto out; | |
299 | } | |
300 | } | |
301 | ||
302 | out: | |
303 | ret = sst25l_write_enable(flash, 0); | |
304 | ||
305 | if (retlen) | |
306 | *retlen = copied; | |
307 | ||
308 | mutex_unlock(&flash->lock); | |
309 | return ret; | |
310 | } | |
311 | ||
06f25510 | 312 | static struct flash_info *sst25l_match_device(struct spi_device *spi) |
ec77e21b RM |
313 | { |
314 | struct flash_info *flash_info = NULL; | |
0ffe0ce3 HS |
315 | struct spi_message m; |
316 | struct spi_transfer t; | |
317 | unsigned char cmd_resp[6]; | |
ec77e21b RM |
318 | int i, err; |
319 | uint16_t id; | |
320 | ||
0ffe0ce3 HS |
321 | spi_message_init(&m); |
322 | memset(&t, 0, sizeof(struct spi_transfer)); | |
323 | ||
324 | cmd_resp[0] = SST25L_CMD_READ_ID; | |
325 | cmd_resp[1] = 0; | |
326 | cmd_resp[2] = 0; | |
327 | cmd_resp[3] = 0; | |
328 | cmd_resp[4] = 0xff; | |
329 | cmd_resp[5] = 0xff; | |
330 | t.tx_buf = cmd_resp; | |
331 | t.rx_buf = cmd_resp; | |
332 | t.len = sizeof(cmd_resp); | |
333 | spi_message_add_tail(&t, &m); | |
334 | err = spi_sync(spi, &m); | |
ec77e21b | 335 | if (err < 0) { |
0ffe0ce3 | 336 | dev_err(&spi->dev, "error reading device id\n"); |
ec77e21b RM |
337 | return NULL; |
338 | } | |
339 | ||
0ffe0ce3 | 340 | id = (cmd_resp[4] << 8) | cmd_resp[5]; |
ec77e21b RM |
341 | |
342 | for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++) | |
343 | if (sst25l_flash_info[i].device_id == id) | |
344 | flash_info = &sst25l_flash_info[i]; | |
345 | ||
346 | if (!flash_info) | |
347 | dev_err(&spi->dev, "unknown id %.4x\n", id); | |
348 | ||
349 | return flash_info; | |
350 | } | |
351 | ||
06f25510 | 352 | static int sst25l_probe(struct spi_device *spi) |
ec77e21b RM |
353 | { |
354 | struct flash_info *flash_info; | |
355 | struct sst25l_flash *flash; | |
356 | struct flash_platform_data *data; | |
d81a32f2 | 357 | int ret; |
ec77e21b RM |
358 | |
359 | flash_info = sst25l_match_device(spi); | |
360 | if (!flash_info) | |
361 | return -ENODEV; | |
362 | ||
b38be288 | 363 | flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL); |
ec77e21b RM |
364 | if (!flash) |
365 | return -ENOMEM; | |
366 | ||
367 | flash->spi = spi; | |
368 | mutex_init(&flash->lock); | |
1594908a | 369 | spi_set_drvdata(spi, flash); |
ec77e21b | 370 | |
0278fd3f | 371 | data = dev_get_platdata(&spi->dev); |
ec77e21b RM |
372 | if (data && data->name) |
373 | flash->mtd.name = data->name; | |
ec77e21b | 374 | |
90b99752 | 375 | flash->mtd.dev.parent = &spi->dev; |
ec77e21b RM |
376 | flash->mtd.type = MTD_NORFLASH; |
377 | flash->mtd.flags = MTD_CAP_NORFLASH; | |
378 | flash->mtd.erasesize = flash_info->erase_size; | |
379 | flash->mtd.writesize = flash_info->page_size; | |
c4cc625e | 380 | flash->mtd.writebufsize = flash_info->page_size; |
ec77e21b | 381 | flash->mtd.size = flash_info->page_size * flash_info->nr_pages; |
3c3c10bb AB |
382 | flash->mtd._erase = sst25l_erase; |
383 | flash->mtd._read = sst25l_read; | |
384 | flash->mtd._write = sst25l_write; | |
ec77e21b RM |
385 | |
386 | dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name, | |
387 | (long long)flash->mtd.size >> 10); | |
388 | ||
289c0522 | 389 | pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) " |
ec77e21b RM |
390 | ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n", |
391 | flash->mtd.name, | |
392 | (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20), | |
393 | flash->mtd.erasesize, flash->mtd.erasesize / 1024, | |
394 | flash->mtd.numeraseregions); | |
395 | ||
ec77e21b | 396 | |
42d7fbe2 AB |
397 | ret = mtd_device_parse_register(&flash->mtd, NULL, NULL, |
398 | data ? data->parts : NULL, | |
399 | data ? data->nr_parts : 0); | |
b38be288 | 400 | if (ret) |
ec77e21b | 401 | return -ENODEV; |
ec77e21b RM |
402 | |
403 | return 0; | |
404 | } | |
405 | ||
810b7e06 | 406 | static int sst25l_remove(struct spi_device *spi) |
ec77e21b | 407 | { |
1594908a | 408 | struct sst25l_flash *flash = spi_get_drvdata(spi); |
ec77e21b | 409 | |
b38be288 | 410 | return mtd_device_unregister(&flash->mtd); |
ec77e21b RM |
411 | } |
412 | ||
413 | static struct spi_driver sst25l_driver = { | |
414 | .driver = { | |
415 | .name = "sst25l", | |
ec77e21b RM |
416 | }, |
417 | .probe = sst25l_probe, | |
5153b88c | 418 | .remove = sst25l_remove, |
ec77e21b RM |
419 | }; |
420 | ||
c9d1b752 | 421 | module_spi_driver(sst25l_driver); |
ec77e21b RM |
422 | |
423 | MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips"); | |
424 | MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, " | |
1c5454ee | 425 | "Ryan Mallon"); |
ec77e21b | 426 | MODULE_LICENSE("GPL"); |