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Ryan Mallonec77e212009-09-18 12:51:40 -07001/*
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>
Ryan Mallon1c5454e2011-06-15 14:45:36 +10008 * Author: Ryan Mallon
Ryan Mallonec77e212009-09-18 12:51:40 -07009 *
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040024#include <linux/sched.h>
Ryan Mallonec77e212009-09-18 12:51:40 -070025
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
51struct sst25l_flash {
52 struct spi_device *spi;
53 struct mutex lock;
54 struct mtd_info mtd;
Ryan Mallonec77e212009-09-18 12:51:40 -070055};
56
57struct 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
Mike Frysinger61cc8272011-05-09 10:07:58 -040067static struct flash_info __devinitdata sst25l_flash_info[] = {
Ryan Mallonec77e212009-09-18 12:51:40 -070068 {"sst25lf020a", 0xbf43, 256, 1024, 4096},
69 {"sst25lf040a", 0xbf44, 256, 2048, 4096},
70};
71
72static int sst25l_status(struct sst25l_flash *flash, int *status)
73{
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -050074 struct spi_message m;
75 struct spi_transfer t;
76 unsigned char cmd_resp[2];
Ryan Mallonec77e212009-09-18 12:51:40 -070077 int err;
78
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -050079 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);
Ryan Mallonec77e212009-09-18 12:51:40 -070089 if (err < 0)
90 return err;
91
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -050092 *status = cmd_resp[1];
Ryan Mallonec77e212009-09-18 12:51:40 -070093 return 0;
94}
95
96static 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
128static 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
147static 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
171static 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);
Jiri Slaby2eaaa5f2009-09-18 12:51:42 -0700193 if (err) {
194 mutex_unlock(&flash->lock);
Ryan Mallonec77e212009-09-18 12:51:40 -0700195 return err;
Jiri Slaby2eaaa5f2009-09-18 12:51:42 -0700196 }
Ryan Mallonec77e212009-09-18 12:51:40 -0700197
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
217static 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
270static 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
326out:
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
Fabio Estevam6b2995b2010-11-26 14:31:44 -0200336static struct flash_info *__devinit sst25l_match_device(struct spi_device *spi)
Ryan Mallonec77e212009-09-18 12:51:40 -0700337{
338 struct flash_info *flash_info = NULL;
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -0500339 struct spi_message m;
340 struct spi_transfer t;
341 unsigned char cmd_resp[6];
Ryan Mallonec77e212009-09-18 12:51:40 -0700342 int i, err;
343 uint16_t id;
344
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -0500345 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);
Ryan Mallonec77e212009-09-18 12:51:40 -0700359 if (err < 0) {
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -0500360 dev_err(&spi->dev, "error reading device id\n");
Ryan Mallonec77e212009-09-18 12:51:40 -0700361 return NULL;
362 }
363
H Hartley Sweeten0ffe0ce2010-04-29 13:34:24 -0500364 id = (cmd_resp[4] << 8) | cmd_resp[5];
Ryan Mallonec77e212009-09-18 12:51:40 -0700365
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
Fabio Estevam6b2995b2010-11-26 14:31:44 -0200376static int __devinit sst25l_probe(struct spi_device *spi)
Ryan Mallonec77e212009-09-18 12:51:40 -0700377{
378 struct flash_info *flash_info;
379 struct sst25l_flash *flash;
380 struct flash_platform_data *data;
381 int ret, i;
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
Brian Norris289c0522011-07-19 10:06:09 -0700413 pr_debug("mtd .name = %s, .size = 0x%llx (%lldMiB) "
Ryan Mallonec77e212009-09-18 12:51:40 -0700414 ".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
Ryan Mallonec77e212009-09-18 12:51:40 -0700420
Dmitry Eremin-Solenikov81939af2011-06-02 17:59:23 +0400421 ret = mtd_device_parse_register(&flash->mtd, NULL, 0,
422 data ? data->parts : NULL,
423 data ? data->nr_parts : 0);
424 if (ret) {
Ryan Mallonec77e212009-09-18 12:51:40 -0700425 kfree(flash);
426 dev_set_drvdata(&spi->dev, NULL);
427 return -ENODEV;
428 }
429
430 return 0;
431}
432
Mike Frysinger61cc8272011-05-09 10:07:58 -0400433static int __devexit sst25l_remove(struct spi_device *spi)
Ryan Mallonec77e212009-09-18 12:51:40 -0700434{
435 struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
436 int ret;
437
Jamie Iles98b39792011-05-23 10:22:59 +0100438 ret = mtd_device_unregister(&flash->mtd);
Ryan Mallonec77e212009-09-18 12:51:40 -0700439 if (ret == 0)
440 kfree(flash);
441 return ret;
442}
443
444static struct spi_driver sst25l_driver = {
445 .driver = {
446 .name = "sst25l",
447 .bus = &spi_bus_type,
448 .owner = THIS_MODULE,
449 },
450 .probe = sst25l_probe,
Mike Frysinger61cc8272011-05-09 10:07:58 -0400451 .remove = __devexit_p(sst25l_remove),
Ryan Mallonec77e212009-09-18 12:51:40 -0700452};
453
454static int __init sst25l_init(void)
455{
456 return spi_register_driver(&sst25l_driver);
457}
458
459static void __exit sst25l_exit(void)
460{
461 spi_unregister_driver(&sst25l_driver);
462}
463
464module_init(sst25l_init);
465module_exit(sst25l_exit);
466
467MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
468MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
Ryan Mallon1c5454e2011-06-15 14:45:36 +1000469 "Ryan Mallon");
Ryan Mallonec77e212009-09-18 12:51:40 -0700470MODULE_LICENSE("GPL");