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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#include <linux/sched.h>
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
32#define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
33
34#define SST25L_CMD_WRSR 0x01
35#define SST25L_CMD_WRDI 0x04
36#define SST25L_CMD_RDSR 0x05
37#define SST25L_CMD_WREN 0x06
38#define SST25L_CMD_READ 0x03
39
40#define SST25L_CMD_EWSR 0x50
41#define SST25L_CMD_SECTOR_ERASE 0x20
42#define SST25L_CMD_READ_ID 0x90
43#define SST25L_CMD_AAI_PROGRAM 0xaf
44
45#define SST25L_STATUS_BUSY (1 << 0)
46#define SST25L_STATUS_WREN (1 << 1)
47#define SST25L_STATUS_BP0 (1 << 2)
48#define SST25L_STATUS_BP1 (1 << 3)
49
50struct sst25l_flash {
51 struct spi_device *spi;
52 struct mutex lock;
53 struct mtd_info mtd;
54
55 int partitioned;
56};
57
58struct flash_info {
59 const char *name;
60 uint16_t device_id;
61 unsigned page_size;
62 unsigned nr_pages;
63 unsigned erase_size;
64};
65
66#define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
67
68static struct flash_info __initdata sst25l_flash_info[] = {
69 {"sst25lf020a", 0xbf43, 256, 1024, 4096},
70 {"sst25lf040a", 0xbf44, 256, 2048, 4096},
71};
72
73static int sst25l_status(struct sst25l_flash *flash, int *status)
74{
75 unsigned char command, response;
76 int err;
77
78 command = SST25L_CMD_RDSR;
79 err = spi_write_then_read(flash->spi, &command, 1, &response, 1);
80 if (err < 0)
81 return err;
82
83 *status = response;
84 return 0;
85}
86
87static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
88{
89 unsigned char command[2];
90 int status, err;
91
92 command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
93 err = spi_write(flash->spi, command, 1);
94 if (err)
95 return err;
96
97 command[0] = SST25L_CMD_EWSR;
98 err = spi_write(flash->spi, command, 1);
99 if (err)
100 return err;
101
102 command[0] = SST25L_CMD_WRSR;
103 command[1] = enable ? 0 : SST25L_STATUS_BP0 | SST25L_STATUS_BP1;
104 err = spi_write(flash->spi, command, 2);
105 if (err)
106 return err;
107
108 if (enable) {
109 err = sst25l_status(flash, &status);
110 if (err)
111 return err;
112 if (!(status & SST25L_STATUS_WREN))
113 return -EROFS;
114 }
115
116 return 0;
117}
118
119static int sst25l_wait_till_ready(struct sst25l_flash *flash)
120{
121 unsigned long deadline;
122 int status, err;
123
124 deadline = jiffies + MAX_READY_WAIT_JIFFIES;
125 do {
126 err = sst25l_status(flash, &status);
127 if (err)
128 return err;
129 if (!(status & SST25L_STATUS_BUSY))
130 return 0;
131
132 cond_resched();
133 } while (!time_after_eq(jiffies, deadline));
134
135 return -ETIMEDOUT;
136}
137
138static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
139{
140 unsigned char command[4];
141 int err;
142
143 err = sst25l_write_enable(flash, 1);
144 if (err)
145 return err;
146
147 command[0] = SST25L_CMD_SECTOR_ERASE;
148 command[1] = offset >> 16;
149 command[2] = offset >> 8;
150 command[3] = offset;
151 err = spi_write(flash->spi, command, 4);
152 if (err)
153 return err;
154
155 err = sst25l_wait_till_ready(flash);
156 if (err)
157 return err;
158
159 return sst25l_write_enable(flash, 0);
160}
161
162static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
163{
164 struct sst25l_flash *flash = to_sst25l_flash(mtd);
165 uint32_t addr, end;
166 int err;
167
168
169 if (instr->addr + instr->len > flash->mtd.size)
170 return -EINVAL;
171
172 if ((uint32_t)instr->len % mtd->erasesize)
173 return -EINVAL;
174
175 if ((uint32_t)instr->addr % mtd->erasesize)
176 return -EINVAL;
177
178 addr = instr->addr;
179 end = addr + instr->len;
180
181 mutex_lock(&flash->lock);
182
183 err = sst25l_wait_till_ready(flash);
184 if (err) {
185 mutex_unlock(&flash->lock);
186 return err;
187 }
188
189 while (addr < end) {
190 err = sst25l_erase_sector(flash, addr);
191 if (err) {
192 mutex_unlock(&flash->lock);
193 instr->state = MTD_ERASE_FAILED;
194 dev_err(&flash->spi->dev, "Erase failed\n");
195 return err;
196 }
197
198 addr += mtd->erasesize;
199 }
200
201 mutex_unlock(&flash->lock);
202
203 instr->state = MTD_ERASE_DONE;
204 mtd_erase_callback(instr);
205 return 0;
206}
207
208static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
209 size_t *retlen, unsigned char *buf)
210{
211 struct sst25l_flash *flash = to_sst25l_flash(mtd);
212 struct spi_transfer transfer[2];
213 struct spi_message message;
214 unsigned char command[4];
215 int ret;
216
217
218 if (len == 0)
219 return 0;
220
221 if (from + len > flash->mtd.size)
222 return -EINVAL;
223
224 if (retlen)
225 *retlen = 0;
226
227 spi_message_init(&message);
228 memset(&transfer, 0, sizeof(transfer));
229
230 command[0] = SST25L_CMD_READ;
231 command[1] = from >> 16;
232 command[2] = from >> 8;
233 command[3] = from;
234
235 transfer[0].tx_buf = command;
236 transfer[0].len = sizeof(command);
237 spi_message_add_tail(&transfer[0], &message);
238
239 transfer[1].rx_buf = buf;
240 transfer[1].len = len;
241 spi_message_add_tail(&transfer[1], &message);
242
243 mutex_lock(&flash->lock);
244
245
246 ret = sst25l_wait_till_ready(flash);
247 if (ret) {
248 mutex_unlock(&flash->lock);
249 return ret;
250 }
251
252 spi_sync(flash->spi, &message);
253
254 if (retlen && message.actual_length > sizeof(command))
255 *retlen += message.actual_length - sizeof(command);
256
257 mutex_unlock(&flash->lock);
258 return 0;
259}
260
261static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
262 size_t *retlen, const unsigned char *buf)
263{
264 struct sst25l_flash *flash = to_sst25l_flash(mtd);
265 int i, j, ret, bytes, copied = 0;
266 unsigned char command[5];
267
268
269 if (!len)
270 return 0;
271
272 if (to + len > flash->mtd.size)
273 return -EINVAL;
274
275 if ((uint32_t)to % mtd->writesize)
276 return -EINVAL;
277
278 mutex_lock(&flash->lock);
279
280 ret = sst25l_write_enable(flash, 1);
281 if (ret)
282 goto out;
283
284 for (i = 0; i < len; i += mtd->writesize) {
285 ret = sst25l_wait_till_ready(flash);
286 if (ret)
287 goto out;
288
289
290 command[0] = SST25L_CMD_AAI_PROGRAM;
291 command[1] = (to + i) >> 16;
292 command[2] = (to + i) >> 8;
293 command[3] = (to + i);
294 command[4] = buf[i];
295 ret = spi_write(flash->spi, command, 5);
296 if (ret < 0)
297 goto out;
298 copied++;
299
300
301
302
303
304 bytes = min_t(uint32_t, mtd->writesize, len - i);
305 for (j = 1; j < bytes; j++, copied++) {
306 ret = sst25l_wait_till_ready(flash);
307 if (ret)
308 goto out;
309
310 command[1] = buf[i + j];
311 ret = spi_write(flash->spi, command, 2);
312 if (ret)
313 goto out;
314 }
315 }
316
317out:
318 ret = sst25l_write_enable(flash, 0);
319
320 if (retlen)
321 *retlen = copied;
322
323 mutex_unlock(&flash->lock);
324 return ret;
325}
326
327static struct flash_info *__init sst25l_match_device(struct spi_device *spi)
328{
329 struct flash_info *flash_info = NULL;
330 unsigned char command[4], response;
331 int i, err;
332 uint16_t id;
333
334 command[0] = SST25L_CMD_READ_ID;
335 command[1] = 0;
336 command[2] = 0;
337 command[3] = 0;
338 err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
339 if (err < 0) {
340 dev_err(&spi->dev, "error reading device id msb\n");
341 return NULL;
342 }
343
344 id = response << 8;
345
346 command[0] = SST25L_CMD_READ_ID;
347 command[1] = 0;
348 command[2] = 0;
349 command[3] = 1;
350 err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
351 if (err < 0) {
352 dev_err(&spi->dev, "error reading device id lsb\n");
353 return NULL;
354 }
355
356 id |= response;
357
358 for (i = 0; i < ARRAY_SIZE(sst25l_flash_info); i++)
359 if (sst25l_flash_info[i].device_id == id)
360 flash_info = &sst25l_flash_info[i];
361
362 if (!flash_info)
363 dev_err(&spi->dev, "unknown id %.4x\n", id);
364
365 return flash_info;
366}
367
368static int __init sst25l_probe(struct spi_device *spi)
369{
370 struct flash_info *flash_info;
371 struct sst25l_flash *flash;
372 struct flash_platform_data *data;
373 int ret, i;
374
375 flash_info = sst25l_match_device(spi);
376 if (!flash_info)
377 return -ENODEV;
378
379 flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
380 if (!flash)
381 return -ENOMEM;
382
383 flash->spi = spi;
384 mutex_init(&flash->lock);
385 dev_set_drvdata(&spi->dev, flash);
386
387 data = spi->dev.platform_data;
388 if (data && data->name)
389 flash->mtd.name = data->name;
390 else
391 flash->mtd.name = dev_name(&spi->dev);
392
393 flash->mtd.type = MTD_NORFLASH;
394 flash->mtd.flags = MTD_CAP_NORFLASH;
395 flash->mtd.erasesize = flash_info->erase_size;
396 flash->mtd.writesize = flash_info->page_size;
397 flash->mtd.size = flash_info->page_size * flash_info->nr_pages;
398 flash->mtd.erase = sst25l_erase;
399 flash->mtd.read = sst25l_read;
400 flash->mtd.write = sst25l_write;
401
402 dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
403 (long long)flash->mtd.size >> 10);
404
405 DEBUG(MTD_DEBUG_LEVEL2,
406 "mtd .name = %s, .size = 0x%llx (%lldMiB) "
407 ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
408 flash->mtd.name,
409 (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
410 flash->mtd.erasesize, flash->mtd.erasesize / 1024,
411 flash->mtd.numeraseregions);
412
413 if (flash->mtd.numeraseregions)
414 for (i = 0; i < flash->mtd.numeraseregions; i++)
415 DEBUG(MTD_DEBUG_LEVEL2,
416 "mtd.eraseregions[%d] = { .offset = 0x%llx, "
417 ".erasesize = 0x%.8x (%uKiB), "
418 ".numblocks = %d }\n",
419 i, (long long)flash->mtd.eraseregions[i].offset,
420 flash->mtd.eraseregions[i].erasesize,
421 flash->mtd.eraseregions[i].erasesize / 1024,
422 flash->mtd.eraseregions[i].numblocks);
423
424 if (mtd_has_partitions()) {
425 struct mtd_partition *parts = NULL;
426 int nr_parts = 0;
427
428 if (mtd_has_cmdlinepart()) {
429 static const char *part_probes[] =
430 {"cmdlinepart", NULL};
431
432 nr_parts = parse_mtd_partitions(&flash->mtd,
433 part_probes,
434 &parts, 0);
435 }
436
437 if (nr_parts <= 0 && data && data->parts) {
438 parts = data->parts;
439 nr_parts = data->nr_parts;
440 }
441
442 if (nr_parts > 0) {
443 for (i = 0; i < nr_parts; i++) {
444 DEBUG(MTD_DEBUG_LEVEL2, "partitions[%d] = "
445 "{.name = %s, .offset = 0x%llx, "
446 ".size = 0x%llx (%lldKiB) }\n",
447 i, parts[i].name,
448 (long long)parts[i].offset,
449 (long long)parts[i].size,
450 (long long)(parts[i].size >> 10));
451 }
452
453 flash->partitioned = 1;
454 return add_mtd_partitions(&flash->mtd,
455 parts, nr_parts);
456 }
457
458 } else if (data->nr_parts) {
459 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
460 data->nr_parts, data->name);
461 }
462
463 ret = add_mtd_device(&flash->mtd);
464 if (ret == 1) {
465 kfree(flash);
466 dev_set_drvdata(&spi->dev, NULL);
467 return -ENODEV;
468 }
469
470 return 0;
471}
472
473static int __exit sst25l_remove(struct spi_device *spi)
474{
475 struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
476 int ret;
477
478 if (mtd_has_partitions() && flash->partitioned)
479 ret = del_mtd_partitions(&flash->mtd);
480 else
481 ret = del_mtd_device(&flash->mtd);
482 if (ret == 0)
483 kfree(flash);
484 return ret;
485}
486
487static struct spi_driver sst25l_driver = {
488 .driver = {
489 .name = "sst25l",
490 .bus = &spi_bus_type,
491 .owner = THIS_MODULE,
492 },
493 .probe = sst25l_probe,
494 .remove = __exit_p(sst25l_remove),
495};
496
497static int __init sst25l_init(void)
498{
499 return spi_register_driver(&sst25l_driver);
500}
501
502static void __exit sst25l_exit(void)
503{
504 spi_unregister_driver(&sst25l_driver);
505}
506
507module_init(sst25l_init);
508module_exit(sst25l_exit);
509
510MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
511MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
512 "Ryan Mallon <ryan@bluewatersys.com>");
513MODULE_LICENSE("GPL");
514
