4 * Driver for SST25L SPI Flash chips
6 * Copyright © 2009 Bluewater Systems Ltd
7 * Author: Andre Renaud <andre@bluewatersys.com>
8 * Author: Ryan Mallon <ryan@bluewatersys.com>
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.
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>
25 #include <linux/mtd/mtd.h>
26 #include <linux/mtd/partitions.h>
28 #include <linux/spi/spi.h>
29 #include <linux/spi/flash.h>
31 /* Erases can take up to 3 seconds! */
32 #define MAX_READY_WAIT_JIFFIES msecs_to_jiffies(3000)
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 */
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 */
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 */
51 struct spi_device *spi;
66 #define to_sst25l_flash(x) container_of(x, struct sst25l_flash, mtd)
68 static struct flash_info __initdata sst25l_flash_info[] = {
69 {"sst25lf020a", 0xbf43, 256, 1024, 4096},
70 {"sst25lf040a", 0xbf44, 256, 2048, 4096},
73 static int sst25l_status(struct sst25l_flash *flash, int *status)
75 unsigned char command, response;
78 command = SST25L_CMD_RDSR;
79 err = spi_write_then_read(flash->spi, &command, 1, &response, 1);
87 static int sst25l_write_enable(struct sst25l_flash *flash, int enable)
89 unsigned char command[2];
92 command[0] = enable ? SST25L_CMD_WREN : SST25L_CMD_WRDI;
93 err = spi_write(flash->spi, command, 1);
97 command[0] = SST25L_CMD_EWSR;
98 err = spi_write(flash->spi, command, 1);
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);
109 err = sst25l_status(flash, &status);
112 if (!(status & SST25L_STATUS_WREN))
119 static int sst25l_wait_till_ready(struct sst25l_flash *flash)
121 unsigned long deadline;
124 deadline = jiffies + MAX_READY_WAIT_JIFFIES;
126 err = sst25l_status(flash, &status);
129 if (!(status & SST25L_STATUS_BUSY))
133 } while (!time_after_eq(jiffies, deadline));
138 static int sst25l_erase_sector(struct sst25l_flash *flash, uint32_t offset)
140 unsigned char command[4];
143 err = sst25l_write_enable(flash, 1);
147 command[0] = SST25L_CMD_SECTOR_ERASE;
148 command[1] = offset >> 16;
149 command[2] = offset >> 8;
151 err = spi_write(flash->spi, command, 4);
155 err = sst25l_wait_till_ready(flash);
159 return sst25l_write_enable(flash, 0);
162 static int sst25l_erase(struct mtd_info *mtd, struct erase_info *instr)
164 struct sst25l_flash *flash = to_sst25l_flash(mtd);
169 if (instr->addr + instr->len > flash->mtd.size)
172 if ((uint32_t)instr->len % mtd->erasesize)
175 if ((uint32_t)instr->addr % mtd->erasesize)
179 end = addr + instr->len;
181 mutex_lock(&flash->lock);
183 err = sst25l_wait_till_ready(flash);
185 mutex_unlock(&flash->lock);
190 err = sst25l_erase_sector(flash, addr);
192 mutex_unlock(&flash->lock);
193 instr->state = MTD_ERASE_FAILED;
194 dev_err(&flash->spi->dev, "Erase failed\n");
198 addr += mtd->erasesize;
201 mutex_unlock(&flash->lock);
203 instr->state = MTD_ERASE_DONE;
204 mtd_erase_callback(instr);
208 static int sst25l_read(struct mtd_info *mtd, loff_t from, size_t len,
209 size_t *retlen, unsigned char *buf)
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];
217 /* Sanity checking */
221 if (from + len > flash->mtd.size)
227 spi_message_init(&message);
228 memset(&transfer, 0, sizeof(transfer));
230 command[0] = SST25L_CMD_READ;
231 command[1] = from >> 16;
232 command[2] = from >> 8;
235 transfer[0].tx_buf = command;
236 transfer[0].len = sizeof(command);
237 spi_message_add_tail(&transfer[0], &message);
239 transfer[1].rx_buf = buf;
240 transfer[1].len = len;
241 spi_message_add_tail(&transfer[1], &message);
243 mutex_lock(&flash->lock);
245 /* Wait for previous write/erase to complete */
246 ret = sst25l_wait_till_ready(flash);
248 mutex_unlock(&flash->lock);
252 spi_sync(flash->spi, &message);
254 if (retlen && message.actual_length > sizeof(command))
255 *retlen += message.actual_length - sizeof(command);
257 mutex_unlock(&flash->lock);
261 static int sst25l_write(struct mtd_info *mtd, loff_t to, size_t len,
262 size_t *retlen, const unsigned char *buf)
264 struct sst25l_flash *flash = to_sst25l_flash(mtd);
265 int i, j, ret, bytes, copied = 0;
266 unsigned char command[5];
272 if (to + len > flash->mtd.size)
275 if ((uint32_t)to % mtd->writesize)
278 mutex_lock(&flash->lock);
280 ret = sst25l_write_enable(flash, 1);
284 for (i = 0; i < len; i += mtd->writesize) {
285 ret = sst25l_wait_till_ready(flash);
289 /* Write the first byte of the page */
290 command[0] = SST25L_CMD_AAI_PROGRAM;
291 command[1] = (to + i) >> 16;
292 command[2] = (to + i) >> 8;
293 command[3] = (to + i);
295 ret = spi_write(flash->spi, command, 5);
301 * Write the remaining bytes using auto address
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);
310 command[1] = buf[i + j];
311 ret = spi_write(flash->spi, command, 2);
318 ret = sst25l_write_enable(flash, 0);
323 mutex_unlock(&flash->lock);
327 static struct flash_info *__init sst25l_match_device(struct spi_device *spi)
329 struct flash_info *flash_info = NULL;
330 unsigned char command[4], response;
334 command[0] = SST25L_CMD_READ_ID;
338 err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
340 dev_err(&spi->dev, "error reading device id msb\n");
346 command[0] = SST25L_CMD_READ_ID;
350 err = spi_write_then_read(spi, command, sizeof(command), &response, 1);
352 dev_err(&spi->dev, "error reading device id lsb\n");
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];
363 dev_err(&spi->dev, "unknown id %.4x\n", id);
368 static int __init sst25l_probe(struct spi_device *spi)
370 struct flash_info *flash_info;
371 struct sst25l_flash *flash;
372 struct flash_platform_data *data;
375 flash_info = sst25l_match_device(spi);
379 flash = kzalloc(sizeof(struct sst25l_flash), GFP_KERNEL);
384 mutex_init(&flash->lock);
385 dev_set_drvdata(&spi->dev, flash);
387 data = spi->dev.platform_data;
388 if (data && data->name)
389 flash->mtd.name = data->name;
391 flash->mtd.name = dev_name(&spi->dev);
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;
402 dev_info(&spi->dev, "%s (%lld KiB)\n", flash_info->name,
403 (long long)flash->mtd.size >> 10);
405 DEBUG(MTD_DEBUG_LEVEL2,
406 "mtd .name = %s, .size = 0x%llx (%lldMiB) "
407 ".erasesize = 0x%.8x (%uKiB) .numeraseregions = %d\n",
409 (long long)flash->mtd.size, (long long)(flash->mtd.size >> 20),
410 flash->mtd.erasesize, flash->mtd.erasesize / 1024,
411 flash->mtd.numeraseregions);
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);
424 if (mtd_has_partitions()) {
425 struct mtd_partition *parts = NULL;
428 if (mtd_has_cmdlinepart()) {
429 static const char *part_probes[] =
430 {"cmdlinepart", NULL};
432 nr_parts = parse_mtd_partitions(&flash->mtd,
437 if (nr_parts <= 0 && data && data->parts) {
439 nr_parts = data->nr_parts;
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",
448 (long long)parts[i].offset,
449 (long long)parts[i].size,
450 (long long)(parts[i].size >> 10));
453 flash->partitioned = 1;
454 return add_mtd_partitions(&flash->mtd,
458 } else if (data->nr_parts) {
459 dev_warn(&spi->dev, "ignoring %d default partitions on %s\n",
460 data->nr_parts, data->name);
463 ret = add_mtd_device(&flash->mtd);
466 dev_set_drvdata(&spi->dev, NULL);
473 static int __exit sst25l_remove(struct spi_device *spi)
475 struct sst25l_flash *flash = dev_get_drvdata(&spi->dev);
478 if (mtd_has_partitions() && flash->partitioned)
479 ret = del_mtd_partitions(&flash->mtd);
481 ret = del_mtd_device(&flash->mtd);
487 static struct spi_driver sst25l_driver = {
490 .bus = &spi_bus_type,
491 .owner = THIS_MODULE,
493 .probe = sst25l_probe,
494 .remove = __exit_p(sst25l_remove),
497 static int __init sst25l_init(void)
499 return spi_register_driver(&sst25l_driver);
502 static void __exit sst25l_exit(void)
504 spi_unregister_driver(&sst25l_driver);
507 module_init(sst25l_init);
508 module_exit(sst25l_exit);
510 MODULE_DESCRIPTION("MTD SPI driver for SST25L Flash chips");
511 MODULE_AUTHOR("Andre Renaud <andre@bluewatersys.com>, "
512 "Ryan Mallon <ryan@bluewatersys.com>");
513 MODULE_LICENSE("GPL");